CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. patent application Ser. No. 10/224,034 filed Aug. 20, 2002, and claims the benefit of U.S. provisional patent applications Ser. No. 60/313,978 filed Aug. 21, 2001 and Ser. No. 60/358,861 filed Feb. 22, 2002. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to hypodermic injection systems, and in particular to those residing in a kit format. It more particularly relates to hypodermic injection systems in kit form for mass inoculations, using electrical or manual power. The invention additionally relates to hypodermic injection systems having ampules that are processed to avoid cross contamination. 
     2. Description of the Prior Art 
     Many forms of hypodermic injection systems are available. These systems include rapid delivery of vaccines/medications with jet injectors that utilize the same orifice for every injection, and in some cases, use individual, single use ampules that must be handled by the vaccinator when filling them with vaccine and/or when inserted or removed from the injector. Some are manually armed, these to include all personal use injectors now available, and some have other means of power such as compressed gas. None of the injection systems are available in kit form that will provide healthcare workers with everything needed to deliver thousands of shots in remote or urban locations before returning to a central location for an equipment re-supply or re-energizing the power sources, and none supply single use, self-destruct ampules in a magazine format that can also be used as a shipping container, or if needed, as a mixing structure for the simultaneous preparation of numerous lyophilized filled ampules. 
     Elements of this disclosure that were considered in earlier patents by at least one of the present inventors are: (1) one ampule per injection found in U.S. Pat. No. 5,080,648, (2) the magazine concept for holding ampules while connected to the injector, and a guard ring around the ampule to discourage splashing are found in U.S. Pat. No. 5,318,522, (3) inserting new ampules and/or discarding used ampules without the need of any physical contact by the user, and also the arming station for compressing an energy storage spring in the hand piece are found in PCT application Serial No. PCT/US00/07470, and (4) perforator (or mini-needle) delivery for reduced pressure and pain to the patient is found in U.S. Pat. No. 6,056,716. One of the present inventors has a pending patent application directed to a structural containment of low cost syringes used at high pressure. Elements from each of the four patents are discussed in the present disclosure for mass immunization systems, clinical injectors, and personal use injectors, and the invention herein will represent improvements or new ways for performing these vital functions for all types of injection systems. The latter patents are all incorporated herein by reference. 
     The invention in its preferred form provides the equipment needed for an electrically powered injection kit, including enough battery power for thousands of injections without means of support required from a central location or conventional sources of power. The basic means of energizing the injector is electrical power; however, as a user option, the kit and injection devices preferably also include a means for manual operation to assure continuation of the injection procedure if the transportable power sources are depleted and/or a source of renewable power is not available. The risk of cross-infection is avoided with disposable, single use, self-destruct ampules (also referred to as cartridges, capsules, vials, etc.) that are designed to interface with the injector in such a way that user contact with the ampules both before and after the injection is unnecessary. In addition, with respect to the preferred embodiment, the trigger is disabled until the ampule is securely held in place with the combination of a grasping jaw assembly and a locking sleeve to prevent the possibility of an ampule becoming a projectile when the injection ram is released. The ampules can be pre-filled by the manufacturer with liquid or lyophilized medication, or can be filled on site if necessary. Also included in the kit are magazines that hold numerous ampules before re-supply is needed. These magazines are designed for rapid, sterile delivery when used with the injector. In some cases, the magazine also serves as the shipping container for the ampules, and has the capability of simultaneous, on site mixing of the lyophilized filled ampules when needed. Alternatively, a filling station provides an efficient and sterile means for filling the ampules with liquid or lyophilized medication just prior to delivery. 
     The method for non-contact changing of ampules has utility for clinical situations and personal use injections as well, where avoiding the risk of cross infection to healthcare workers is critically important when dealing with patients harboring dangerous pathogens. By the same token, where the risk of cross infection is not a factor, such as patients receiving insulin, or perhaps the daily delivery of growth or other hormone injections, the patient or healthcare worker assisting them can easily handle the ampule for both insertion and removal with the novel grasping system disclosed. The availability of this system has special utility for people who find the prior art techniques for filling the ampule and manually arming personal-use injectors to be physically challenging, if not impossible, in some cases. 
     For all of the injection scenarios discussed, very short perforators (1 to 2 mm) as the exit nozzle, and used for piercing the injection site prior to jet delivery, are included in the preferred embodiment because they allow for low pressure injections (200 to 1,000 psi) as opposed to typical jet injection pressures on the order of 2,000 to 3,500 psi or more. Properly contained ampules, as discussed in the pending U.S. patent application referred to above, open the door for manufacturer-modified insulin and other syringes having 27 or 28 gauge needles that are already produced by the hundreds of millions, which when supplied at perforator length will provide an injection orifice on the order of 0.008 or 0.007 inches, which are typical diameters for jet injection systems. The economy of this approach is quite substantial. 
     SUMMARY OF THE INVENTION 
     The object of this invention is to provide a new, high-speed injection system that is economical, technically suited to campaigns for mass immunization and meets the needs of reliability, ergonomics, power availability, cost, safety and effective injections. The system is designed with several options for both powered and manual operation so that the needs of a wide variety of users can be met, these to include clinical and personal use injection systems. One option for powering the injector is an embodiment wherein a motor is remote from the handpiece discussed below, and referred to as a “Motor-Off Tool” (MOT) “Handpiece” with three methods including both electrical and manual means for compressing the injection spring. Also available is another embodiment wherein a motor is included in the handpiece, and referred to as a “Motor-In-Tool” (MIT) “Handpiece” similar to that reported in earlier disclosures by at least one of the inventors; however, according to a preferred embodiment in this disclosure, rather than a rotating cam mechanism for compressing the energy storage spring, a gear reduction and ball screw are used to do the same thing which provides novel methods and advantages for operating the motor in both the forward and reverse directions. For example, motor reversal allows for increasing the speed of rapid, repetitive injections by compressing the injection spring in one direction and then reversing direction for an immediate return to the starting point in preparation for the next arming cycle regardless of whether or not the present injection is delivered. An internal switching arrangement determines when the motor drive reaches the intended location, then provides an appropriate signal to first stop, latch the spring, and then reverse motor direction at the appropriate time. This sequence of repeated motor reversal takes place for every injection cycle, the distance of travel in each direction being determined by the volume of injectate to be delivered. In every case described, the mass immunization kit will also include a means for manual delivery if necessary; and this system has utility as a manual device for clinical situations. 
     In an alternate embodiment, the forward direction of the motor allows for the ball screw drive to completely eliminate the energy storage injection spring by using a direct drive delivery from the motor to the ampule piston. One of the advantages of direct drive is the ability to provide an ever-increasing drive voltage to the motor that, in turn, will yield a profile of increasing pressure over the course of an injection. This increasing pressure will drive the injectate ever deeper, rather than ever more shallow, which will discourage the inclination of medication being left on the surface as is sometime seen with the usual spring driven, orifice oriented systems. This feature is especially useful for personal use injectors used by diabetics who are often very sensitive to the correct amount of insulin entering the body. Availability of reversing motor direction can also be used for filling an empty ampule, and has particular utility with personal use injectors as an improvement to the tedious manual methods now in use. To do this, the injector ram will first grab the plunger of an empty in-dwelling ampule, and then, with a push button command by the user, the injector will pull the plunger back to draw vaccine from a supply connected to the front end of the ampule. Mechanical or magnetic means can be used to make this connection to the ampule piston. Once the ampule is full by virtue of the reverse direction, a low speed button controlled motor drive will allow the vaccinator to slowly “jog” the piston forward, and visually determine when all air is expelled from the ampule. For direct drive delivery, the motor is then transferred to its high-speed mode to drive the injectate into the injection site. 
     The ampules are designed for interfacing with a circular set of grasping jaws on the front of the injector. In one embodiment, the system comprises the following: (1) the ampules are packaged on a tear-away paper strip, (2) a filling station fills the ampules with pre-mixed, liquid vaccine while attached to the strip, (3) two different magazine options are available that house the ampules for rapid, easy insertion into the magazine, and then, one by one into the injector, (4) the injection is followed by self-destruction of used ampules, (5) two different handpiece options (the choice depending on user circumstances), and (6) several options for compressing the spring. The high-speed manual option mentioned earlier is an especially important feature for financially strapped countries that are unable to afford higher-level injection systems. The primary means for arming the automatic injector is electrical power for energizing a motor that serves to compress an injection spring. It should be noted that the spring-energized injector options are virtually always adaptable to manual operation as either a primary or emergency back-up system. This option is not available with conventional compressed gas, CO 2  or ignitable gas drive systems. 
     Also disclosed are means for an on site mixing of pre-filled individual ampules having lyophilized medication in one compartment, and its mixing diluent in a companion compartment, the two being separated by an appropriate barrier. Several means are shown for utilizing a barrier between the medication and its diluent. The barrier can be frangible or a one-way valve. In one embodiment, a filling station will provide sufficient force for filling the individual ampules with pre-mixed liquid vaccine through the exit nozzle, an option that is also useful for the personal use injectors described above. This approach for front end filling will virtually eliminate the problem of having air enter the chamber that usually occurs when filling ampules by creating a vacuum when drawing back on the plunger. Alternatively, the filling station can provide sufficient force to insert the diluent through the exit nozzle and then mix it with lyophilized medication located in the ampule. 
     A new concept of a mixing magazine allows for simultaneous, on-site mixing of an entire magazine full of the pre-filled, lyophilized/diluent cartridges. In this case, the magazine can also be used as the shipping container from the manufacturer to anywhere in the world thus, of course, lowering cost and further reducing the risk of contamination due to intermediate handling. 
     In summary, the system includes a transportable injection station or kit that is easily moved from place to place by foot, bicycle, motor scooter, motorcycle, water, air transport or whatever means is available for moving people and equipment to an immunization site. If no other working surface is conveniently available at the site, legs provided as part of the station are opened and extended to the proper height for the user, and optional flat panels from one to all of the four sides of the housing are extended to form a working surface if needed. When the kit is opened, the healthcare worker will have everything needed for thousands of injections without any other means of support for the amount of time expected at the location. As mentioned above, the kit will include magazines of the selected type, filling station if needed, enough battery power to provide the number of shots expected, and a module for manually arming the injector in the event that all battery power is unexpectedly depleted, and/or the power needed for recharging the batteries is not available. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a pictorial view of a portable injection system or kit according to the invention; 
         FIG. 2  is a partially exploded, pictorial view of one embodiment of the invention having a motor off the tool; 
         FIG. 3  is a pictorial view of a mechanical arming system for use with the embodiment shown in  FIG. 2 ; 
         FIG. 4  is a pictorial view of an electrical or optionally manual arming station for compressing an injection spring in the embodiment shown in  FIG. 2 ; 
         FIG. 5   a  is a pictorial view of a Motor-In-Tool injector having a removable motor and battery module for arming the Motor-In-Tool embodiment of the invention; 
         FIG. 5   b  is a pictorial view of a motor-In-Tool injector having a removable motor module for the Motor-In-Tool embodiment of the invention; 
         FIG. 5   c  is a pictorial view of a removable, back-up manual-arming module for the Motor-In-Tool embodiment of the invention; 
         FIG. 6   a  shows a permanent Motor-In-Tool injector according to the invention, in pictorial form; 
         FIG. 6   b  is a cut-away view of the Motor-In-Tool injector illustrated in  FIG. 6   a , showing its internal mechanism; 
         FIG. 7   a  is a cut-away view of a second injector for the embodiment of the Motor-In-Tool invention depicted in  FIG. 6   a , showing its internal mechanism in its armed condition; 
         FIG. 7   b  is a partly cut-away front view of the injector shown in  FIG. 7   a  also showing the internal mechanism in its armed condition; 
         FIG. 7   c  is a cut-away side view of the injector shown in  FIG. 7   a  showing its internal mechanism in its fired or unarmed condition. 
         FIG. 7   d  is a cut-away front view of the injector shown in  FIG. 7   c  showing its internal mechanism in its fired or unarmed condition. 
         FIG. 8   a  is a cut-away view of a version of an injector for the first embodiment of the invention for the Motor-Off-Tool injector shown in  FIG. 2  with an ampule illustrated with a perforator at the exit port; 
         FIG. 8   b  is an enlargement of the ball transfer subsystem shown in  FIG. 8   a    
         FIG. 8   c  is an enlargement of the jaw structure for grasping ampules as shown in  FIG. 8   a;    
         FIG. 8   d  is an illustration of one embodiment for self-destruction of a perforator after use in  FIG. 8   a;    
         FIG. 9  is a pictorial view of a used ampule being ejected from the jaw structure shown in  FIG. 8   c;    
         FIG. 10   a  is a pictorial view of an unused, empty ampule according to an embodiment of the invention; 
         FIG. 10   b  is a pictorial view of the ampule shown in  FIG. 10   a  filled and ready to deliver an injection; 
         FIG. 10   c  is a pictorial view of the ampule shown in  FIG. 10   a  in the disabled state after an injection has been given; 
         FIG. 11   a  is a perspective view of an alternate embodiment of a frangible piston for use in the ampule shown in  FIGS. 10   a - 10   c;    
         FIG. 11   b  is an end view of the piston shown in  FIG. 11   a;    
         FIG. 11   c  is a view taken along the line A-A in  FIG. 11   b;    
         FIG. 12   a  is a pictorial view of a portion of the invention showing ampules attached to a cardboard/paper strip; 
         FIG. 12   b  is an enlargement of a portion of  FIG. 12   a;    
         FIG. 13   a  is a pictorial view of the ampule strip shown in  FIG. 12   a  when inserted in an unfolded magazine; 
         FIG. 13   b  is an enlargement of a portion of  FIG. 13   a  showing a close-up view of posts for securing ampule strips to a folding magazine; 
         FIG. 13   c  is a pictorial view of the apparatus shown in  FIG. 13   a  with a set of magazine wings being folded over the center segment; 
         FIG. 13   d  is a pictorial view of the apparatus of  FIG. 13   a  in a fully-folded magazine ready for injection; 
         FIG. 14   a  is a pictorial view of another embodiment of an aspect of the invention showing an ampule strip coiled up and placed in a rotating auto-feed magazine; 
         FIG. 14   b  is a pictorial view of the embodiment shown in  FIG. 14   a  with a cover placed on the rotating auto-feed magazine shown in  FIG. 14   a  and ready for use; 
         FIG. 14   c  is a pictorial view of a negator spring used in the magazine shown in  FIGS. 14   a - 14   b ,  16 ,  17  and  18   a - 18   c.    
         FIGS. 14   d  and  14   e  are schematic drawings of a pawl and ratchet device used in the magazine shown in  FIGS. 14   a ,  14   b ,  16 ,  17  and  18   a - 18   c.    
         FIG. 15  is a pictorial view of ampules according to the invention located in a tray or crate assembly; 
         FIG. 16  is a pictorial view of the second embodiment of the invention shown in  FIG. 2  retrieving a filled ampule from a rotating auto-feed magazine as shown in  FIGS. 14   a  and  14   b;    
         FIG. 17  is a pictorial view of another embodiment of the magazine portion of the invention showing a linear auto-feed magazine with an open cover; 
         FIG. 18   a  is a pictorial view of another embodiment of the magazine aspect of the invention showing a rotatable auto-feed magazine with an improved structure for ampule retrieval; 
         FIGS. 18   b  and  18   c  are views of the magazine shown in  FIG. 18   a  in two mounting modes. 
         FIG. 19  is a pictorial view of a filling station according to the invention in partially exploded form; 
         FIG. 20   a  is a schematic view of an ampule according to the invention with a lyophilized/diluent vaccine separated by a mixing piston with a one-way valve; 
         FIG. 20   b  is a schematic view of the ampule shown in  FIG. 20   a  with internal lyophilized vaccine and external mixing diluent being forced into the exit nozzle; 
         FIG. 20   c  is a schematic view of an ampule according to the invention with lyophilized vaccine, having an external appendage containing the mixing diluent; 
         FIG. 20   d  is a schematic view of the ampule shown in  FIG. 20   c  having an external appendage containing both lyophilized vaccine and diluent separated by a barrier; 
         FIG. 20   e  is a schematic view of another aspect of the invention showing a magazine full of ampules, each with a collapsible storage unit; and 
         FIG. 20   f  is a schematic view of another variation of an ampule according to the invention showing it with lyophilized vaccine and diluent separated by a slidable frangible barrier. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  illustrates a customized, all-inclusive, carrying case  12  for the portable injection system, station or kit  10  according to an embodiment of the invention. Each carrying case  12  of the portable system  10  contains all components necessary for a healthcare team to efficiently administer thousands of injections at the rate of up to 600 people per hour, this equipment to include several magazines  1 , at least one handpiece  2 , enough battery power  3  for the number of injections expected, manual arming means  4  if needed, at least one filling system  5 , several battery charging options  6  and simple tools  7  to effect repairs to the system components. 
     The case has retractable legs (not shown) for standing the unit in an upright position and flat panels from the four sides that can be pulled out to form a working surface (not shown) for the healthcare team if no other surfaces are available or convenient. Sterile components such as gauze, cotton balls, band-aids  8 , etc., will also be housed in the case. Several ampule strips  9  should be included in the case as a fill-in or backup in case a delay occurs in the normal procedure for delivery; however, for the enormous number of inoculations needed for a mass immunization campaign, it is anticipated that the required number of ampules will be transported to the site in separate cartons and/or shipping magazines, and might even contain pre-filled liquid or lyophilized ampules. 
     One of the main embodiments of the invention is referred to as a “Motor-Off-Tool” or “MOT,” where the electrically operated motor (discussed below) is separable from the injection device that it is driving. The injection device preferably includes a handpiece for effecting injections. 
       FIGS. 2 through 4  are illustrations of the various ways to deal with arming a Motor-Off-Tool (MOT) device, i.e., it includes a handpiece  14  containing an injection spring (discussed below) and a trigger  16 , but a motor  15  and a battery  17  are on motor-battery belt assembly  18  are located off of handpiece  14 . Because of this, MOT handpiece  14  is less expensive and extremely light at an estimated weight of approximately 8.5 ounces (240 g), where the handpiece is made from an appropriate plastic, and the plastic and injection spring comprising nearly all of the weight of the handpiece. The reduced weight has the added advantage of less fatigue to the healthcare worker when thousands of injections are given. 
       FIG. 2  shows a Motor-Off-Tool apparatus  100  having a belt-motor assembly located on a belt pack  22 , arm pack or the like, and is attachable to a convenient location on the healthcare worker giving the injections. A moveable center (not visible but similar to a speedometer cable) located inside tether or cable  26  is fastened on one end to a draw rod (discussed below) on handpiece  14 , and is used for applying the pulling force needed to compress an injection spring in handpiece  14 , also discussed below. The outside shell of tether  26  is connected to handpiece  14  with a coupler mechanism  24 . The other end of the movable center of cable  26  is attached to a motor drive  19  located on belt back  22 , and this end of tether or cable  26  is attached to the housing of motor drive  19  with a coupler or connection mechanism  28 . After an injection is given, a signal goes back from the handpiece to the motor control which will instruct the motor to pull on the movable center of cable  26  to again compress the spring in preparation for the next injection as explained later. The injection fluid or injectate is held in disposable ampules  21 . This option allows the vaccinator to move around freely and provides for very high-speed operation, all the while requiring very little outside assistance. Mechanical tether  26  should be of adequate strength, and could be fairly stiff which, for some situations will also possibly add unwieldy weight to handpiece  14 . 
       FIG. 3  illustrates a manually operated foot pedal assembly  30  for activating the movable center of mechanical tether  32  which functions exactly as described for tether  26  in  FIG. 2  for compressing the spring in handpiece  14 . The outer shell of tether  32  is connectable to handpiece  14  with coupler mechanism  34 . No additional energy is needed and no motor is involved for using this foot-operated device. 
       FIG. 4  shows a pair of Motor-Off-Tool (MOT) injectors residing in rearming station  40 ; however, in this case an electrically operated arming station  42  is used. While not mandatory, the primary objective of arming station  42  is for the vaccinator and an assistant to work together, wherein the vaccinator will give the shots and the assistant will move the handpieces around as described below. Arming station  42  has a pick-up cradle  44  for holding a fully armed Motor-Off-Tool injector, and a rearming dock or port location  50  to accept an unarmed injector. Arming station  42  can be adapted to hold more than one MOT handpiece, wherein two are shown in  FIG. 4  as configured for use with an assistant. Cradle  44  on arming station  42  is for holding an injector  14  that has already been armed and ready for use. A pick-up cradle adjustment knob  46  on arming station  42  is adjustable in order to place the handpiece at an angle that is most convenient and comfortable to provide access to a fully armed injector  14  for the vaccinator. Arming station  42  also has an arming station base  48  on which the aforementioned pick-up cradle  44  and a rearming dock or cradle  50  is located. In addition, base  48  also has an optional or back-up manual arming lever  52  to rearm the handpiece resting in dock or cradle  50  in the event electrical power is not available, all of which are discussed below. At the beginning of an immunization sequence, both injectors are typically unarmed. When arming cradle  50  senses the presence of handpiece  14 , it pulls the injector draw rod to compress the injection spring to the latched position, as discussed hereinafter. After arming is completed, the armed handpiece is moved to pick-up cradle  44 , and the second injector is placed in arming cradle  50  and armed. At this point, the vaccinator takes an armed injector from cradle  44  to give an injection and the assistant will move the second injector to pick-up cradle  44  while at the same time the vaccinator will squeeze trigger  16  of handpiece  14  to then release the injection spring, therein driving a ram in handpiece  14  to expel the jet velocity fluid from the ampule. After giving an injection, the vaccinator ejects used ampule  21  and deposits handpiece  14  into the now empty rearming cradle or dock  50 , and picks up the armed handpiece  14  from cradle  44  wherein handpiece  14  is ready to retrieve a new ampule  21  for the next injection. Benefits with arming station  40  include the elimination of any kind of tether, so that the vaccinator&#39;s arm has complete freedom of movement. Also, in a campaign with an adequate supply of assisting personnel, which is often the case in mass campaigns, arming station  40  will relieve the vaccinator from all duties except for delivering injections, thus insuring an efficient, high-speed operation. If, however, a vaccinator is working with very little assistance, the arming station  40  option would require more motion and effort on the part of the vaccinator than the mechanical tether option. Also, unlike the mechanical tether option, in which the vaccinator can move around freely, this option requires the vaccinator to remain close to the arming station in order to swap handpieces  14  after each injection. The arming station concept is also conveniently applied to the personal use injector, wherein the motor and battery can be housed in a unit that also serves as a compact storage and carrying case that is easily concealed by the user, and which also makes the handpiece very compact, lightweight and easily maneuvered for a personal injection. 
     A second main embodiment of the invention is referred to as a “Motor-In-Tool” or “MIT,” where an electric motor is plugged into or otherwise is a part of the injection device which it is driving, in this case a handpiece as described below. Referring to  FIGS. 5   a - 5   c , they show together a Motor-In-Tool device or apparatus  200  having a handpiece  114 , and in the embodiment of  FIG. 5   b , a battery-belt assembly  118  having a battery  120 , and a motor module with a motor  119 . 
       FIGS. 5   a - 5   c  illustrate various options for arming the Motor-In-Tool (MIT) injector or handpiece  114 . Depending on the required shot capacity, battery  120  can be housed on handpiece  114  or in a separate off-tool compartment as shown in  FIG. 5   b . Just like the Motor-Off-Tool (MOT) handpiece  14 , the MIT handpiece  114  houses an injection spring, the force transfer system that includes a plunger rod such as ampule plunger rod  403  as illustrated in  FIGS. 8   a - 8   c , trigger, and the ampule grip/release system as discussed in greater detail below. Thus, with reference to  FIGS. 10   a - 10   c , ampule  21  includes an injecting piston  718 . Piston  718  is driven forward by plunger rod  403  to force injectable material into the intended target. 
       FIG. 5   a  illustrates a removable module  130  containing a geared down motor  132 . Depending on the desired injection pressure and stroke length for a particular injector design, any number of conversion values could be used, one value implemented for this system has an armature speed as high as 13,900 revolutions per minute (RPM), but with very low torque. This high armature speed is reduced by 29:1 with an appropriate gear reduction to yield an output speed of 480 RPM to shaft  136  (8 revolutions per second), and except for an inevitable loss due to conversion efficiency, the torque output is therefore increased by the same ratio, thus providing the power needed to compress the injection spring (not shown in this figure). In this embodiment, a battery  134  is connected to the motor inside of module  130 , wherein both the motor and battery are connected to the handpiece  114  during its operation by insertion of an output shaft  136  into a mating receptacle  138  on handpiece  114 . 
       FIG. 5   b  illustrates a removable module that contains only the geared down motor  119  when the motor is connected to handpiece  114 , but battery  118  is off the tool during operation and is connected to motor  119  with an electrical tether  140 . Motor  119  has the same type motor shaft  136  as shown in  FIG. 5   a  for insertion into receptacle  138 . This is a more likely situation for providing power to handpiece  114  when thousands of injections are expected, i.e., a larger remote battery pack can be clipped onto a belt or vest, carried in a pocket, or placed on a stationary surface next to the vaccinator without the risk of excessive fatigue from constantly moving the greater weight. The MIT handpiece  114  (that is, when motor  119  is connected thereto) is estimated to weigh about 14 ounces and is somewhat larger than an MOT handpiece  114  (when motor  119  is not connected); however, it is still much lighter than any other mass campaign injector known to the inventors. The MIT handpiece  114  weighs about 14.5 to 16.5 ounces, wherein added to the 8.5-ounce MOT handpiece  114  are motor  119  at about 4 ounces and the linkage from the motor to the gears weighing from 2 to 4 ounces. The option shown in  FIG. 5   b  provides the vaccinator full range of arm motion and complete freedom to walk around; that is, handpiece  114  does not have to be put down between injections and one-handed operation to load, inject, and eject ampules  21  is possible. While not shown, it is clear than other sources of power, such as solar or main power, when converted to the voltage needed can also be used to drive the motors in  FIG. 5   b.    
       FIG. 5   c  shows a module  142  for the manual arming of handpiece  114 , and which is connected to the injector in the same manner as that described for the modules of  FIGS. 5   a  and  5   b . This format takes the place of the motor and the battery pack needed to energize it. Module  142  has a housing  144 , and a manually driven handle  148  coupled to geared down interface prior to moving output shaft  146  which is connected to receptacle  138  on handpiece  114  during its operation. Manual arming of handpiece  114  is facilitated by rotating handle  148  several times to provoke the amount of rotation needed on output shaft  146  to compress the injection spring. While not shown in any of the figures, the MIT injector  200  can also be manually rearmed by compressing the spring from the front end when the injector nose is inserted into a corresponding manual rearming station. 
       FIGS. 6   a  and  6   b  show one version of a complete MIT injector including a handpiece  114 ′, and  FIG. 6   b  is a cut-away view of the motor location and the other significant components. In this case, motor  119 ′ receives power from electrical tether  140  as illustrated in  FIG. 5   b , but in this case, motor  119 ′ is a permanent fixture on handpiece  114 ′. This figure also includes an ampule grip/release system, force transfer system, trigger, and the injection spring, all which are also incorporated in the MOT design  100 . Ampule  21  is not installed in handpiece  114 ′ in these figures. 
     With reference to  FIG. 6   a , handpiece  114 ′ has a housing  150  with a trigger  116 ′. Turning to  FIG. 6   b , an injection spring  152  is shown in the compressed state and is held in compression between a ball screw nut  154  and an injection release sleeve  156  having a shoulder  158  against which spring  152  rests, wherein, motor  119 ′ rotates a ball screw  164  which subsequently rotates ball screw nut  154  in the spring compression direction until it reaches and actuates a motor stop switch which is more fully explained with the embodiment of  FIG. 7 . Optionally, the spring can be made to latch in this position and the motor is instructed to immediately return ball screw nut  154  to a lower portion of ball screw  164 . Alternatively, ball screw  154  can stay in the position shown until the injection is given and the used ampule released from the handpiece, at which time, the motor will reverse the ball screw position as described to be reset to again compress spring  152 . Both techniques have been implemented, the advantage of immediate reversal is saving time in preparation for the next injection. A force transfer system  160  transfers force from injection spring  152  to system  160  and ultimately to a ram for driving a piston inside an ampule. Motor  119 ′ is mounted in housing  150  and has a drive shaft  161  for rotating a spur gear  163 , which in turn rotates a spur gear  162  to rotate ball screw  164  which moves ball screw nut  154  to compress injection spring  152 . No thrust bearing is required for protecting drive shaft  161  because the load is decoupled from the motor and the gearbox by virtue of the offset nature of the spur gears. An electric tether connector port  166  is shown as a connection for connecting a battery or, as suggested for the  FIG. 5  embodiments, connecting other sources of electrical power to motor  119 ′. 
     Force transfer system  160  includes a casing  168  for holding an ampule plunger rod, a transfer mechanism held in casing  168 , and a ramrod extending from injection release sleeve  156  to effect the active operation of the transfer mechanism. The ampules are held in handpiece  114 ′ by gripper jaws  172 , the operation of which is discussed in further detail for  FIG. 8   c  below. The foregoing mechanism included in handpiece  114 ′, with the exception of motor  119 ′ installed in handpiece  114 ′, is essentially the same as for the MOT handpiece  14 . 
     When trigger  16 ,  116  or  116 ′ is squeezed on any of handpiece  14 ,  114 ,  114 ′, the stored energy in injection spring  152  exerts the appropriate force on transfer system  160  (more fully described below for  FIG. 8   a ), which then applies injection pressure to an ampule ramrod (discussed below). After an injection, an ampule release button  170  is compressed and the ampule capture sleeve (discussed below) is pulled back from its locked position. The gripper jaws  172  expands, are held open, and the used ampule  21  either falls out or is pushed away from the front end of handpiece  114 ′. There is no need for physical contact by the user; however, if desired, ampule  21  can be inserted and extracted manually. As described above, at some point in the cycle, motor  119 ′ reverses its direction to reset handpiece  114 ′. To install a new ampule  21 , the front end of the handpiece  114 ′ is placed over the mating back section of a new ampule  21 , and the capture sleeve is returned to the locked position as soon as gripper jaws  172  are released and closed. The ampule is now securely held in place for the next injection. Apparatus is provided for preventing the actuation of a ramrod for normally injecting injectate from an ampule unless gripper jaws  172  are properly holding an ampule because the actuation of the ramrod without a properly held ampule could pose a dangerous situation since the ramrod could provide a dangerous impact if it were to strike a person. 
       FIGS. 7   a ,  7   b ,  7   c  and  7   d  show the internal structure for one embodiment of the MIT injector  200 . Injector  200  has a handpiece  114 ″ shown in  FIGS. 7   a  and  7   b  in the armed position, and  FIGS. 7   c  and  7   d , the same in the fired or unarmed position. MIT handpiece  114 ″ includes a housing  150 ′ having a ball screw assembly  172 , which includes a motor and gear train  119 ″, a coupler mechanism  174 , a ball screw  164 ′ and a ball nut  154 ′. Coupler mechanism  174  represents a fixed point which locks the motor in the housing while at the same time coupling motor  119 ″ and its gear box (included in the motor or housing) to ball screw  164 ′. Member  174  is able to pivot very slightly (a few degrees) to allow for movement of ball screw  164 ′ and a power linkage  176  as ball screw nut  154 ′ moves up and down on ball screw  164 ′ during the arming process. Coupler mechanism  174  also includes a thrust bearing (not detailed in the figure) to protect the motor and gear train from the in-line spring load. Power linkage  176 , described in more detail below, operatively attaches to ball screw assembly  175  with an appropriate connector or pivot point  192 . The injector spring is included in a rear or right part of a spring tube assembly  178 . A battery  118 ′ is located within housing  150 ′ above spring tube assembly  178 . An ampule capture sleeve  180  holds an ampule  21 . The discharge or removal of a used ampule  21  is accomplished by the sidewise movement of an ampule release trigger  182 . A ready indicator  184  is located at the rear of headpiece  114 ″ and extends out the rear end of injector  200  as shown when the injection spring is compressed. A front view of the unit is shown in  FIG. 7   b.    
     Power linkage  176  includes a first link  186  connected to ball screw nut  154 ′ by connector  192  about which first link  186  can pivot. Link  186  has a free end  188  with a longitudinal slot  190 . A second link  194  is connected to a pin or pivot pin  196  extending from trigger  116 ″. Second link  194  can pivot about pin  196 . A third link  198  is pivotally mounted on a pivot pin  201  carried on a tube housing  202  which allows pivot  201  to slide to the left when the injection spring is released, and a fourth link  204  is mounted at one end to a pivot pin  206  fixed on handpiece  114 ″, and at its other end to a connecting pin  208  extending through slot  190  in first link  186 . Link  198  is connected to fourth link  204  by means of the same connecting pin  208  for second link  194 . Pin  208  is held in place by a retainer  210 . 
     As mentioned,  FIG. 7   a  shows MIT handpiece  114 ″ in a loaded or armed position. When trigger  116 ″ is actuated, injection release or second link  194  is forced upwardly by trigger  116 ″, therein, connecting pin  208  is raised above the center point of links  198  and  204  to unlock these links, and the compression spring in spring tube assembly  178  is released and rapidly moves to the left, driving an ampule plunger rod or ramrod into ampule  21  to cause the discharge of the injectate held therein. Connecting pin  208  moves to the upper end of slot  190  in first link  186 , and then, in this embodiment (other motions are possible), upon the sidewise actuation of ampule release trigger  182 , an ampule-eject spring engages an ampule ejector sleeve which both withdraws jaw capture sleeve  180  to release jaw expansion springs (not shown in this figure) from holding ampule  21  in place in handpiece  114 ″, and a plunger return and ampule-eject spring drives an ejector sleeve against ampule  21  to either eject or to allow ampule  21  to fall away from the open gripper jaws (discussed in detail with respect to  FIG. 8   c ). The condition of handpiece  114 ″ after firing, i.e. after an injection has been made and just prior to ejection of ampule  21  from the gripping jaws  172 , is shown in  FIG. 7   c.    
     Ampule release  182  can also release an ampule in the event no injection is made. It also effects release of an ampule if the main system malfunctions. 
     It is noted that the fully compressed spring in this embodiment latches with a slightly over-center toggle composed of third link  198  and fourth link  204 ; therefore, spring release is easily facilitated with a small force to the center point of this toggle arrangement when trigger  116 ″ is actuated. Ball nut  154 ′, screw  164 ′ and motor drive  119 ″, move in both the forward and reverse directions by virtue of electrical switch actuation as described below. As described earlier, a ready button  184  extending from the rear end of housing  150 ′ tells the user when injector  114 ″ is fully armed for an injection. 
     After an injection has been accomplished and injector  200  moves from the condition in  FIG. 7   a  to that of condition  7   c , the direction of rotation of the shaft of motor  119 ″ is reversed. Control of motor  119 ″ is facilitated with the use of switches  214 ,  216 , and  218 . When trigger  116 ″ is actuated and toggle  204 / 198  is released to facilitate the injection, trigger  116 ″ also causes a switch arm  212  to move upward with a guide and stop member  220  riding along a slot  213 , thereby releasing switch  216 . The release of switch  216  enables motor  119 ″, but this alone will not permit it to operate. At this point, there are two possible embodiments for having the motor rearm the injector. In the first embodiment, when ampule release trigger  182  is actuated and the used ampule falls away from the injector, switch  218  is released, and the combination of switch  216  and  218  enable motor  119 ″ to rearm the injector  200 , at which time, ball nut  154 ′ moves in the downward direction along screw  164 ″. When nut  154 ″ reaches the bottom of ball screw  164 ′, arm  212  slides downward with guide and stop member  220  riding along slot  213 , and switch  216  is again compressed, while at the same time, toggle  204 / 198  latches to its slightly over center position. Re-compression of switch  216  when ball screw  154 ′ reaches the bottom causes motor  119 ″ to reverse direction and ball  154 ′ immediately returns to the upward part of screw  164  as shown in  FIG. 7   a . When ball screw  154 ′ reaches the top, it pulls on shaft  215  which in turn produces a slight pull on coupler  174  to pull coupler  174  away from switch  214 , and the motor stops. In an alternative embodiment for rearming the injector, motor  119 ″ reversed direction as soon as the injection is completed. This saves time between shots, however, it also provides the risk of dry firing the injector if the trigger is pulled before a new, filled ampule is inserted into the injector. The choice between the two embodiments is determined by the conditions where the injector is to be used. 
     It should be noted that the manual backup, i.e., for situations where electrical power is unavailable, could be just as fast as automatic arming, but fatigue to the user could be much greater due to the physical energy needed at the rapid rate expected. Whatever the case, the manual feature is necessary to assure that all injections are completed at the location before the healthcare team moves on. 
       FIGS. 8   a - 8   c  illustrate the details of a complete Motor-Off-Tool injector  400 ; however, the inner workings, with the exception of how it is armed, apply to the Motor-In-Tool injector as well. 
     The  FIG. 8   a  cut-away shows the off-axis energy transfer system consisting of a series of balls in a tube and all of the other elements described above. The off-axis transfer of power was developed in order to provide a handpiece that was less threatening to children than the gun type structure that has typically been used. This model is also easier to handle than the straight-line version (similar in shape to a conventional flashlight), provides for a better distribution of weight, and helps reduce the onset of fatigue to the healthcare worker. Several methods were reduced to practice, each having its own advantages and disadvantages for certain situations in mass immunization. 
     Referring to  FIG. 8   a , MOT  400  includes a handpiece  414  having a housing  450  with a trigger  416 , and a force transfer system  402  having ampule plunger rod  403 , force transfer balls  405  and a ramrod  407 . Force transfer balls  405  are held in and tangential to the inside surface of curved housing  409 . Handpiece  414  further includes a draw rod  411 , a spring tube  413  housing an injection spring  415  and a spring retainer nut  417 . An injection release sleeve  456  includes part of curved housing  409  with force transfer balls  405 , as well as six release balls  419  which can be transferred from an annular channel  421  to an annular pocket  423 . Handpiece  414  has an ampule release button  425  and leaf springs  427 . Ampule release from the front end jaw structure is essentially the same as that described for  FIG. 8   c  below. 
       FIG. 8   b  is a blown-up view of force transfer balls  405  shown in  FIG. 5   a . Balls  405  are preferably made from steel, and there are “hat” members  429  inserted between each of the balls that are intended to improve the efficiency of this transfer by helping maintain alignment of the balls to reduce wall friction. Hat members  429  are preferably made from Delrin. While not shown in the figures, tube  409  can also contain a hydraulic fluid with sealing pistons at either end, rather than balls  405 . The fluid, along with these pistons, will transfer the power to ampule plunger rod  403  when the injection spring  415  is released. Tubular transfer system  402  is the most compact and lightest weight of those disclosed; however, its efficiency is not as great as some of the others; for example, while somewhat larger, a chain or cable connected to a pulley and gear motor combination can also provide the spring compression at higher efficiency. Selection of a particular transfer system will depend on the energy available to accommodate an acceptable efficiency, as well as the premium placed on weight and size of the device. 
       FIG. 8   c  is a blown up view of the circular jaw structure shown in  FIG. 8   a . As pointed out earlier and discussed below, these jaws allow for a no-personal contact procedure when grasping and discarding an ampule, and because of that, they also have important utility for personal use injectors when used by healthcare workers for a particular patient who might be harboring dangerous blood born pathogens, thus eliminating the risk of cross infection to the worker. 
     In  FIG. 8   c , an ampule  21  is held in handpiece  414  by three gripper jaws  472 . Ampule  21  has a housing  700  with a cylindrical forward outer surface  702  and a tapered rearward surface  704  that is narrow at its free end and thickens until it reaches a peak  706  after which it tapers inwardly towards the longitudinal axis of ampule  21  to form a slanting shoulder  708 . Gripper jaws  472  each have a head  475  with an inclined ampule engaging surface  476  for engaging ampule shoulder  708 . Jaws  472  are biased outwardly by jaw expansion springs  478 . A jaw capture sleeve  480  engages an abutment  482  on the outside of head  475  of jaws  472  to hold jaws  472  in a closed position against the bias of springs  478 . Plunger rod  403  follows the longitudinal axis of jaws  472  and ampule  21  (if installed), and as explained earlier, effects the ejection of serum or other injectate from ampule  21 . A guide and holder  484  has a forward end portion with an inclined inner surface  486  for engaging and holding inclined rearward surface  704  of ampule  21 , an inward collar  488  and a rearward cylindrical portion  490 . An ejector sleeve  492  extends partially along plunger rod  403 , and the inner surface of collar  488  of rearward portion  490  of gripper jaws  472  engages sleeve  492  and holds it against plunger rod  403 . A plunger return and ampule spring  494  extends partially along plunger rod  403 , including a forward portion between ejector sleeve  492  and plunger rod  403 . 
     A jaw capture sleeve return spring  496  extends along the inside surface of the rear part  497  of jaw capture sleeve  480 , and has a forward end abutting an inwardly extending collar  498  of sleeve  480  and a rear end abutting a gasket  500  extending between the rearward end of sleeve  480  and the rearward portion  490  of guide and holder  484 . A retaining ring  502  is located in an annular groove  504  of guide and holder  484  for maintaining gasket  500  and sleeve and return spring  496  in place. 
       FIG. 8   a  shows the MOT injector  400  in its loaded or armed condition, ready for giving an injection. The user actuates trigger  416  by causing it to pivot on an annular axle (hidden in this figure but located close to the left end centerline of plunger rod  403 ), which causes a cam  506  on trigger  416  to engage an inclined surface  508  to force injection release sleeve  456  downwardly along tube  409  containing balls  405 . This causes injection release balls  419  to move from annular channel  421  into annular pocket  423  in injection release sleeve  456 . Balls  419 , which had been restricting the release of injection spring  415  in spring tube  413 , now permit the release of spring  415 . Therein, injection spring  415 , which at its upper end engages a drive member  510 , in turn drives draw rod  411  into ramrod  407  to apply the force from spring  415  into force transfer balls  405  to move upwardly, the forward ones of which moving around the curve in the upper end of tube  409 , to drive plunger rod  403  into the inner end of ampule  21  of such force as to cause the ejection of injectate under jet pressure through its discharge port  710 . 
     It is noted that ampule  21  in this embodiment is shown with an exit port perforator  460  covered by a collapsible protective front end  462  whose interior contains a springy or resilient return material. When front end  462  is pressed against an injection site, it collapses under the applied force to then expose perforator  460  through the narrow access hole at the front. The perforator now enters the very outer layer of the body and the injection is thereafter delivered. When the injection is completed, protective cover  462  re-expands to again cover perforator  460  thus avoiding the risk of injury to the user. Importantly, protective front end  462  is manufactured with a side-wise bias that breaks lose when the perforator is first exposed, consequently, when perforator  460  is drawn back into protective front end  462 , the narrow exit hole in  462  will shift to the side as shown in  FIG. 8   d , therefore making it impossible to again expose perforator  460 . This feature provides protection against any form of after shot “stick” or reuse by preventing the perforator from again becoming exposed, and will, in fact, destroy the perforator is such front end compression is again applied. 
     Thereafter, the actuation of ampule release button  425  withdraws jaw capture sleeve  480  to the left as shown in  FIG. 8   c , away from forward end  702  of ampule  21 . This results in jaw expansion springs  478  rotating gripper jaws away from ampule  21  so that ampule-engaging surface  476  disengages ampule shoulder  708 . Plunger return and ampule-eject spring  494  urges ejection sleeve  492  forwardly against the rear face  712  of ampule  21  to eject ampule  21  from MOT handpiece  414 . 
     Since this embodiment is that of a motor-off-tool (MOT) injector, withdrawal of ramrod  407  from the forward or fired position must first be facilitated before a new ampule can be inserted into gripper jaws  472 . Thus, injector  414  is inserted into either a motor driven arming station or a manually driven arming station to grab hold of draw rod  411  and pull on it to recompress spring  415  to the injection ready position. A new ampule  21  can now be inserted in the forward end  485  of guide and holder  484 , and jaw heads  475  will ride along inclined surface  704  of ampule  21  until peak  706  rides over the gripping portion of jaw head  475  to releasably lock ampule  21  in place. Jaw capture sleeve return spring  496  then moves jaw capture sleeve  480  to the right as shown in  FIG. 8   c , to move gripper jaws  472  to the closed position. 
     MOT handpiece  414  is now ready for the next injection. The entire system in this and other embodiments have been found to make  600  injections per hour, including the injection of injectate from each ampule, discarding the ampule and reloading a new ampule. 
       FIG. 9  illustrates a full external view of the  FIG. 7   a - 7   c  MIT injector  200  as seen when ejecting a used ampule  21  into a trash container T without the need for any physical contact by the user. 
       FIGS. 10   a - 10   c  are three views of one version of a self-destruct ampule that is conveniently used with this injection system. 
       FIG. 10   a  shows ampule  21  prior to filling. In order to maintain consistency as to the location of the proximal and distal ends of the ampule for the discussions to follow, the proximal end is always that end which is closest to the injector, i.e., the part of the ampule that is held by the grasping jaws described earlier. Each ampule  21  includes its thin plastic shell or housing  700 , cylindrical forward outer surface  702 , tapered rearward surface  704 , peak  706 , shoulder  708 , an orifice or discharge port  710  and rear face or proximal end  717 . A channel or bore  714  forms a chamber  715  extending along the longitudinal axis of ampule  21 , and is open at the rearward or proximal end  717  of ampule  21 . Orifice  710  is located at the forward or distal end  716 . Injection piston  718  is located at the distal end  716  while a spool  720  and a locking spring assembly  722  remain at proximal end  717 . Piston  718  is made from an appropriate plastic and has a head portion  724 , a body  726  and a base  728 . Spool  720  has a head  730 , a body  732  and a base  734 . Locking spring  722  is wrapped around body  732  of spool  720 , and has leaf spring members or fingers  736  which are biased outwardly from the longitudinal axis of ampule  21  towards the side wall  714  of chamber  715 . The leaf members  736  of the locking spring  722  apply slight outward pressure to the inner diameter (ID) of bore  714 , thus enabling locking spring assembly  722  to maintain position within bore  714 . Herein lies another feature that, in some cases, would find use with a personal use injector. However, it should be noted that in some cases where dangerous pathogens are not an issue, some personal use injectors actually promote the reuse of ampules to facilitate greater economy to the user. 
       FIG. 10   b  shows a filled ampule. The distal end  716  of ampule  21  is installed into the filling station (shown in greater detail in  FIG. 19 ), and pressurized injectate is forced into chamber  714  through the orifice  710 , thus driving piston  718  towards spool assembly  720  at proximal end  717  of ampule  21 , wherein it makes physical contact with spool  720  and locking spring  722  and comes to a stop. Due to outward pointing fingers  736  of locking spring  722 , assembly  720  is unable to move any further in the proximal direction. The concept of filling through the exit port with the application of pressure to the vaccine reservoir offers a substantial advantage by avoiding the insertion of air into the injectate chamber during the filling process. This as opposed to the more common practice of creating a vacuum in the injectate chamber when the plunger is pulled back. While the pulling procedure certainly draws fluid into the injectate chamber, it also draws air in at the same time, therein requiring an extra step of carefully pushing the plunger forward until all of the air is expelled before giving the shot. 
       FIG. 10   c  depicts an ampule  21  after the injection is completed. Plunger rod  403  makes contact with end or base  734  of spool  720 , thus driving the spool  720 , locking spring assembly  722  and piston  718  forward at high speed to force the high velocity injectate out through orifice  710  as a coherent jet stream. Once the injection is complete, piston  718  is firmly lodged in distal end  716  of ampule  21 , making reuse virtually impossible to further reduce the likelihood of cross infection. 
       FIGS. 11   a - 11   c  depict an alternate embodiment of the piston used in ampule  21  that avoids the use of a locking spring to disable the ampule, but relies instead on a very thin frangible section just behind an O-ring seal on the piston. After the piston reaches the end of the injection stroke and strikes the distal end of the ampule, the injector ram continues in the forward direction just far enough to produce an additional compression force on the piston which provokes a separation, or breakage, of the piston at the frangible ring. Once the piston is broken into two parts, reuse of the ampule is impossible. In another form of the same idea, the injector ram fractures a frangible center section on the piston. After the piston has fully pushed forward to complete the shot, a movable center rod will continue beyond the end of the ram and force a hole in the frangible member; therefore, if a user tries to refill the ampule, the remains of the piston cannot be moved to the full position. 
     Thus, still referring to  FIGS. 11   a  and  11   b , an ampule piston  750  is shown. Piston  750  has a head  752 , a body  753 , and an annular groove  754  separated by a pair of surfaces  756 ,  758  by a distance sufficient to engage in sealing contact an O-ring  760 . An elongated, annular groove  762  extends between a pair of collars  764 ,  766 . A closed bore  768  ( FIG. 11   c ) extends from an end  770  of piston  750  and ends in a conical surface  772 . The narrow portion  774  between conical surface  772  and surface  758  of groove  754  forms a frangible web area. As explained above, in use a ram such as ampule plunger rod  403 —when activated—is driven into the rear surface  770  of piston  750  as it moves through its injection stroke to eject injectate from an ampule such as ampule  21  from chamber  715  through orifice  710 . After ampule piston  750  reaches the bottom of ampule  21 , plunger rod  403  continues its forward motion until its compressive force breaks the frangible web area at narrow portion  774 , rendering piston  750  useless and ampule  21  disabled against reuse. 
     The item shown in  FIGS. 12   a  and  12   b  is an example of ampules  21  connected together on an ampule strip  800  comprising a cardboard and paper combination, with tear-away paper strip  802  looping over each of the ampules as they rest on cardboard backing  804 . Ampules  21  are affixed to the cardboard backing when the paper overlay  802  is secured to the cardboard backing  804  by a suitable adhesive  806 . Cardboard backing  804  extends beyond distal face  716  of each ampule  21 , protecting the orifice  710  from incidental contact and possible contamination during handling. A loop belt  808  is configured and serpentined in such a way as to form folds  810  to hold ampules  21  securely inside of each other in the folded over strip during shipping, handling, and filling, but allows ampules  21  to be easily torn away when a shear load is applied by the handpiece jaws (such as jaws  472 ) when pulling ampules  21  out of ampule strip  800 , i.e., a tear-away system. Ampules  21  in  FIGS. 12   a  and  12   b  are shown prior to insertion into the magazine system (described in more detail below). An alternate embodiment (not shown) has the ampules connected together during the molding process, but insertion into the magazine and the tear, or breakaway feature is essentially the same. 
     Each ampule strip  800  preferably contains a number of 0.5 ml ampules  21 . Reconstitution of a 50-dose cake of lyophilized vaccine with 30 ml of diluent typically yields more than 50 doses of vaccine, especially with the highly efficient filling station described below. While a greater number is possible, the number of ampules in the strip will be equal to half the average number of doses of vaccine the filling station will extract from the vial (i.e. two ampule strips per vial of vaccine, wherein a strip will preferably hold between 26-28 ampules). As shown in  FIGS. 12   a  and  12   b , ampules  21  are spaced approximately 10 mm (0.400″) apart, allowing strip  800  to fold in half lengthwise ( FIG. 12   a ), nesting ampules  21  facing one another into the intervening spaces ( FIG. 12   b ) for ease of shipping and filling. 
     The folded strip will be removed from its sterile pouch and interfaced directly with the filling station (as discussed below) advancing iteratively to allow the filling nozzle to access each ampule  21  and force reconstituted vaccine through its orifice  710  described above for  FIGS. 10   a - 10   c . The vaccine will push ampule piston (such as piston  718  or  750 ) back until it stops against a pre-installed spool (such as spool  720 ) and lock ring (such as locking ring  722 ), insuring a precise amount of injectate in each ampule  21 . This spool and lock ring will also prevent the piston from moving in the reverse direction once the injection is completed, thus disabling the ampule and preventing reuse. Once the ampules  21  are filled, strip  800  is ready to go into cold storage for use later in the day or to be installed directly into a magazine. 
       FIGS. 13   a - 13   d  and  14   a - 14   b  show two distinct, yet similar, off-tool ampule management systems available with the injection station of  FIG. 1 , and the handpiece designs described above. By virtue of the ampule strip design in  FIGS. 12   a - 12   b , a greater number of ampules are available for the off-tool magazines than that described for the on-tool magazines of prior art patent U.S. Pat. No. 5,318,522. Either of the magazines can be attached to a working surface, such as the injection system carry case, a table, a lanyard around the user&#39;s neck, belt pack, arm pack or wrist mounting, and/or any other convenient location. 
     The magazine  820  shown in  FIGS. 13   a - 13   b  is a folding magazine. This system holds a set of ampules  21  in a fixed position relative to one another, and are removed from any location, one at a time by the handpiece. This system comprises three plastic segments: a center segment  822  and two winged sections  824 ,  826  hinged to each side. Segments  822 ,  824 ,  826  are initially unfolded, and the open magazine is placed on a flat surface, allowing the ampule strip to be laid into the unfolded magazine ( FIG. 13   a ). Small posts  828  ( FIG. 13   b ) on the inner surface of magazine segments  822 ,  824 ,  826  press securely into a set of matching holes  832  in an ampule strip backing  830 , properly locating strip backing  830  on the support walls  834 ,  836 ,  838  ( FIG. 13   c ) on each of segments  822 ,  824 ,  826 , and holding it in place. Additionally, an edge  840  of backing  830  closest to proximal end  717  of ampules  21  fits firmly against retaining rib  708  on the inside surface of magazine segments  822 ,  824 ,  826 , keeping strip backing  830  from sliding while ampules  21  are being extracted one at a time. Ampule strip  800  when inserted in magazine  820  includes a loop belt  842  attached to strip backing  830  by an appropriate means such as an adhesive. Loop belt  842  and backing  830  are flexible so that they can bend with the folding of magazine  820 . Loop belt  842  has a sequence of loops  844  being generally semi-cylindrical for grasping ampules  21  around ampule body  702  to hold ampules  21  in place. Retaining rib  708  extends across each of segments  822 ,  824 ,  826  for engaging the edge of ampule strip  800  when it is inserted in the magazine. Segment  822  has two pairs of opposing hinge arms  848 ,  849  for cooperating with hinge arms  850  on each of segments  824 ,  826  for forming two pairs of hinges  852 . Hinge arms  850  each have a pin  854  for extending through a hole  856  in hinge arms  848 ,  849  to complete respective hinges  852 . Segment  824  has an end plate  858  and segment  826  has an end plate  860  with a handle  862  attached to it by some appropriate means or to be integral therewith. Finally, the segments  824 ,  826  are folded over center segment  822 , left segment  824  first ( FIG. 13   c ). The end of right segment  826  snaps fully over the opposite ends of the center segment  822  and left segment  824 , holding the system securely closed in its folded position ( FIG. 13   d ). Snapping occurs by virtue of opposing fingers  864  extending from hinge arms  850  into opposing notches  866  in end plate  860 . Strip backing  830  and loop belt  842  have strategically positioned pleats or perforations  868 ,  870  to allow the folding to occur easily. The folded magazine  820  ( FIG. 13   d ) has a solid bottom surface because of foot flanges  872 ,  874 ,  878  on each of segments  822 ,  824 ,  826 , to protect ampule distal ends  716  and also to provide a place for possibly securing magazine  820  to a surface, either through hook-and-loop strips (e.g. Velcro©) or features which affix to matching surfaces on the injection system carry case. Folded magazine  820  also has solid sides  880 ,  882 , which allow for gripping the magazine with one hand while extracting the ampules with the handpiece jaws. The relative position of the ampules in the magazine allows access to each ampule in turn. Proximal ends  717  of the remaining ampules provide some guidance to the nose of the handpiece, helping the user locate the handpiece nose (such as gripper jaw heads  475 ) appropriately for jaws (such as jaws  472 ) to grasp the targeted ampule. After the last ampule  21  has been extracted, magazine  820  can be unfolded, ampule strip backing  830  removed and discarded, and a new strip backing  830  of filled ampules  21  installed. The advantage of folding magazine  820  is simplicity. With few parts and few manipulations necessary to operate, this magazine design is likely to be robust and take minimal time to load and unload. Protection of the orifice or distal end  716  of ampule  21  prevents the possibility of cross infection, but because proximal ends  717  of ampules  21  are exposed, some effort must be made by the user to insure cleanliness. 
       FIGS. 14   a - 14   b  illustrate a rotating auto-feed magazine  890 . This system advances the ampule strip along a track, presenting each ampule at a consistent location for extraction. As with folding magazine  820 , this system  890  is ideal for placement on a table, attached to the injection system case, or ideally, on the opposite wrist to the hand used to hold the injector. If desired, auto-feed magazine  890  could also be worn as a neck lanyard by the vaccinator. This magazine  890  comprises a load chamber  892  that holds the ampule strip (such as strip  800  of  FIG. 12   a ) and a rotating take-up spool  898  that collects the empty strip as the ampules are removed, and is similar in operation to the film advance system of a camera ( FIG. 14   a ). This embodiment includes four primary components: a base  894 , a cover  896  ( FIG. 14   b ), take-up spool  898 , and a constant-force negator spring  900  ( FIG. 14   c ) located and attached to the inside of spool  898 . Spring  900  is shown outside of spool  898  with  FIG. 14   c  for clarity. Housing base  894  has a bottom wall  902 , side walls  904  and interior guide walls  906  for cooperating with the inside surfaces of side walls  904  to guide strip backing  908  of ampule strips  909  through load chamber  892 . Wall  906  is also appropriately curved at wall section  910  so that load chamber  892  can receive take-up spool  898 . Cover  896  has a rim  912  that is configured to slip over and slidingly engage the upper portion of side walls  904 . Take-up spool  898  has a slot  914  for receiving a tab  916  and strip backing  908 , for holding tab  916  as take-up spool  898  rotates to draw ampule strip  800  (or  900  in  FIG. 14   a ) along its path in magazine  890 . Ampule strip  909  has ampules  21  secured to strip backing  908  by some appropriate means, such as disclosed with reference to  FIGS. 13   a - 13   d.    
     In preparation for inserting ampule strip  909  into magazine  890 , the user pulls the wind-up cord (not shown, but see  FIG. 17  for an equivalent one) which turns take-up spool  898  through several revolutions (counterclockwise in this figure) to turn spring  900  to the fully wound and latched position. A ratchet-type arrangement having a pawl  918  and a ratchet groove  929  will prevent the cord from being pulled back into the housing by wound up spring  900  because of the vertical left side on groove  929  and mating spring loaded pawl  918  on the interior of magazine  890 , however, the slanted surface on the right side of groove  929  will allow spool  898  to rotate in the counter clockwise direction during wind-up by having spring loaded member  918  slide over the slanted surface during each revolution. To facilitate loading magazine  890 , ampule strip  800  is rolled into a coil and placed in load chamber  892  ( FIG. 14   a ). The user then threads an extended tail or tab  916  of strip backing  908  along the track or path as described above, affixing it to rotatable take-up spool  898 . When cover  896  is placed on to housing base  894 , an appendage on the inside of cover  896  (not shown) extends downward to interface with the surface of spring loaded pawl  918  and push it out of the way to release take up spool  898 . Application of spring tension from constant force spring  900  located in housing base  894  draws strip backing  908  onto spool  898  until an ampule  21  comes to rest against a stop position defined by wall portion  926 . Cover  896 , which can optionally be attached to the housing base by a hinge on housing base  894 , is then placed over base  894  to protect the ampules against contamination ( FIG. 14   b ). As stated above, the ratchet is released when pawl  918  is pushed out of mating groove  929  in the closing of cover  896 . This should be made clear by considering  FIGS. 14   d  and  14   e . In order to cock or set spring  900  prior to the loading of a strip of ampules, a pull cord is pulled to rotate spool  898  counterclockwise. As spool  898  is wound counterclockwise as shown in  FIG. 14   a , spring loaded pawl  918  slides into groove  929  but does not stop the rotation due to the sliding of the inclined surfaces of pawl  918  and groove  929  passing over each other. However, once a strip of ampules is inserted in load chamber  892 , spring  890  would be free to unwind spool  898 . This cannot occur, however, since while spring  900  could unwind, spool  898  moves a small amount due to pawl  918  moving below spool  898  as shown in  FIG. 14   e . Nevertheless, while pawl  918  moves into groove  929  as shown in  FIG. 14   d , the ampule strip is locked in place. When cover  896  is closed, a bar  897  moves pawl  918  downward so that it cannot stop the clockwise rotation of spool  898  as ampules are advanced through magazine  890 . This action-reaction will free spring  900  and advance ampules  21  on backing strip  908  as described. 
     A funnel-like opening  930  in cover  896  provides access to the ampule  21  resting against the stop defined by wall portion  926 . The funnel feature allows the nose (the head of the gripping jaws) of the handpiece to be guided easily into position to grasp the ampule flange, i.e. the portion near proximal end  717 . Once an ampule  21  is extracted, spring  900  turns spool  898  and automatically brings the next ampule  21  into position at access opening  930 . After the last ampule  21  has been extracted, cover  896  is removed so that ampule strip  909  can be removed and discarded. A new ampule strip  909  is then installed as described above. Position of the pull-cord at all times is an indicator of the number of ampules remaining in magazine  890  as the cord is stepwise pulled into the housing when ampules  21  are extracted. Auto-feed magazine  890  makes use of the handpiece easier, because the ampule access point (opening  930 ) is always at the same place and the funnel in the cover (e.g. conical) can guide the jaws into position. To allow for the unlikely case of magazine malfunction, a slot  932  in housing side wall  904  provides a manual feed option where the user can pull the strip to advance the next ampule  21  into position for retrieval by the handpiece. 
       FIG. 15  illustrates the ampules housed in a crate assembly rather than the magazine structure described above. Accordingly, a crate  940  is provided which is made of cardboard, plastic or other appropriate material, which has a series of orifices  942  defining the entrance to receptacles  944  for receiving distal ends  716  of ampules  21  with proximal ends  717  extending from receptacles  944  for engagement by jaws of an appropriate handpiece. While this is the least expensive way to manage ampules  21 , it is also the most likely to risk contamination and/or accidental spilling onto the floor. 
       FIG. 16  illustrates an ampule  21  being extracted from auto-feed magazine  890  ( FIG. 14 ) by injector  200  shown in  FIG. 9 . Ampule  21  could also be grabbed and extracted from folding magazine  820  ( FIG. 13 ) or crate  940  ( FIG. 15 ) with the same injector jaw assembly. 
       FIG. 17  illustrates an in-line version of auto-feed magazine  890  shown in  FIG. 14  and is geometrically similar to stationary magazine  820  shown in  FIG. 13   d . This in-line type magazine is the preferred embodiment in some cases because it reduces the amount of handling of the ampule strip, i.e., the packaging alignment is similar to the way it will be inserted into the filling station, and after that, into the magazine itself. This is easier and faster than trying to coil the ampule strip for use with the rotating magazine shown in  FIGS. 14   a  and  14   b . The in-line magazine is also easier to hold and equally convenient for wrist mounting if so desired. Thus,  FIG. 17  shows in-line magazine  950  having a housing  952  comprised of a base  954  and a cover  956  connected to base  954  by an integral hinge  958 . A spring wound take-up spool  960  (using negator spring  900 ) is disposed in an appropriately figured compartment  962  of housing  952 . A longitudinally extending dividing wall  964  extends between compartment  962  and an end  966  of housing  952 . A path for an ampule strip is defined between the opposite side surfaces of dividing wall  964  and the inside surfaces of opposing side walls  968 ,  970  of base  954 . An ampule strip such as strip  800  in  FIG. 12   a  could be used. It extends from a base end and extends to a connecting end attached to spool  960 . A nylon pull-cord  972  for winding up negator spring  900  is shown in this  FIG. 17 , and is the same as that described above for magazine  890  in  FIGS. 14   a ,  14   b . In both auto-feed magazines  890 ,  950 , the housing can also be transparent for a visual appraisal of the number of ampules remaining. A funnel-shaped opening  973  is provided for presenting the proximal end  717  of ampules  21  for grasping by the jaws of an injector. 
       FIG. 18   a  is another embodiment of the rotating auto-feed magazine. However, rotating auto-feed magazine  980  as shown has a housing with a cover  984  and a base  986 . Cover  984  has a set of V-like rails  988  to virtually guide the injector nose into a funnel-shaped opening  990  where an ampule  21  appears for being grasped or retrieved with little or no visual contact by the user. For this reason, this embodiment is called a “noseeum” model; however, ampules  21  are grabbed by the jaw assembly the same as that described for the other magazine embodiments. It is noted that the “noseeum” feature is very important in high-speed procedures where it was found that delivery efficiency is greatly improved when the vaccinator is able to keep his/her eyes on the next patient rather than looking around for the next ampules  21 . 
       FIG. 18   b  illustrates magazine  980  in the released position from a mounting bracket  989 , and  FIG. 18   c  shows magazine  980  in the secured position in the mounting bracket  989 . Mounting bracket  989  can be any appropriate bracket in the market. 
       FIG. 19  is an illustration of an ampule filling station  990  described above and will be included in injection kit  10  of  FIG. 1 . The purpose of filling station  990  is to accelerate the ampule fill rate. It could have a fill rate capacity in excess of 600 ampules per hour in order to keep up with patient throughput, or several filling stations with slower fill rates could be used simultaneously. A more likely scenario would be to use a slower fill rate filling station to pre-fill a large quantity of ampules before the start of vaccine administration. It is preferred that each ampule be addressed individually in a serial manner (as opposed to collectively in a parallel manner) to minimize maintenance/cleaning of the fluid path, reduce the chance of entrapping air bubbles, and reduce the possibility of contamination. 
     Filling station  990  includes a housing  991  and a manual fluid transfer handle  992 . A magazine  993 , which could be one of those discussed above, receives ampules  21  on a strip, such as ampule strip  800  shown in  FIG. 12   a . A shroud  994  is used to cover magazine  993  in order to reduce the likelihood of contamination. After magazine  993  housing empty ampules is inserted into the filling station at access port  997 , injectate is forced into ampules  21  one by one upon the actuation of handle  992 , which effects the filling of ampules  21  from injectate contained in syringe  998 . The full magazine  995  exits the filling station at an exit  996  of filling station  990 . The filled magazine  995  is again covered with a shroud  994  when it exits from filling station  990 . 
     In an alternate embodiment, ampules can be provided in strips  800  that interface with filling station  990  directly. After being filled in much the manner as described above, strips  800  of filled ampules may then be placed immediately into magazine  993  or placed into cold storage to be installed in magazines just before use. While considering the various means for filling ampules  21  for mass immunization campaigns, and as mentioned above, the assumption is made that the vaccine is available in a 50-dose vial of lyophilized vaccine with the associated 30 ml vial of diluent. Single-dose or ten-dose vials may also be used, but the increased frequency of swapping vials will slow the overall filling process accordingly. The possible means for filling include: 1) forcing injectate through output orifice  710  as illustrated with filling station  990  shown in  FIG. 19 , 2) forcing injectate through the piston (similar in nature to that discussed below with reference to  FIG. 20   a , which refers to the use of lyophilized vaccine), and 3) pulling injectate through orifice  710  by drawing on the piston. Use of a piston to facilitate filling from a filling station (as opposed to forcing the vaccine in through the orifice when using the filling station) poses several problems. The small diameter of the piston (0.186 in, 4.72 mm), coupled with the lack of an ampule plunger in the injection system disclosed, makes it very difficult to create an appropriate interface to the filling station. The precision needed to interface with a smaller component could very well lead to problems in the rougher treatment expected in the field. This concept was therefore not included in filling station  990  of  FIG. 19  as discussed above, but it does fall within the scope of the invention. The orifice at distal end  710  of ampule  21  provides for a more user-friendly interface due to the increased outside diameter of ampule  21  (0.375 in, 9.53 mm). Filling station  990  therefore preferably uses distal end  710  of ampule  21 . Forcing the injectate into ampule  21  by use of a large syringe  998  as shown in  FIG. 19 , or by pressurizing the vial containing the reconstituted vaccine have all been considered. Pumping air into the vial (i.e., avoiding transfer of syringe  998 ) to pressurize the contents could be accomplished via a simple ball type pump (bulb) such as that found on a sphygmomanometer or via a mechanically actuated syringe pump. A more complicated system utilizing a motor driven pump, with manual override, is possible but would add cost, weight and complexity to the portable system. The main difficulty in using the vial comes in the valving required to control flow of air into the vial and flow of injectate out of the vial. In addition, how to control and monitor the pressure within the vial is at issue. The complexity of valving, coupled with the need for pressure control, favors a standard large syringe  998  as a solution for filling the ampules, and this is what is shown in  FIG. 19 . The syringe requires no valving, external pressurization, or pressure monitoring, to provide an accurate fill. In addition, and importantly, standard practice uses large syringes to mix the diluent with the lyophilized vaccine, and the same syringe  998  could then be used to then fill the ampules. A custom interface is provided for the syringe/vial interaction (i.e. for mixing diluent with lyophilized vaccine and for drawing mixed vaccine into syringe  998 ), or users could continue using standard needles to mix vaccine and to draw vaccine from the vial into the syringe. When filling ampules  21  from the syringes, advancement of the syringe plunger is accomplished via a simple lever action  992 , or alternatively, a more, complicated motor driven means. Many of these issues were addressed when settling on the filling station of  FIG. 19  and have been eliminated with the use of ampules  21  that are pre-filled with liquid vaccine as described, or much better, the lyophilized pre-filled ampules  21  as described for  FIGS. 20   a - 20   f  below. 
     The series of ampule and magazine configurations illustrated in  FIGS. 20   a - 20   f  are directed to the very important concept of the vaccine/medication manufacturers pre-filling the ampules prior to shipping them to the user. Pre-filling provides the promise for numerous improvements in some very important healthcare concerns, especially so in campaigns for mass immunization. Two of the most difficult considerations are time and sanitation, both of which are nicely addressed with the concepts disclosed. Time for preparation is a crucial factor for an immunization campaign in the difficult conditions often found in third world countries, and sanitation is virtually non-existent in some of these situations where misuse and mishandling runs rampant. This is especially true when it comes to handling the syringes and vaccine both before and after the injections are given. 
     The concepts found in  FIGS. 20   a - 20   f  also address the problems that have long existed for pre-filled ampules. Plastic, for example, has long been banned for vaccine storage because of the possibility of leaching. While recent findings indicate that some of the higher-grade medical plastics may be satisfactory for long-term storage for vaccines, final approval remains to be seen; consequently, the concepts described in  FIGS. 20   a - 20   f  deal with both plastic storage and the long-accepted means of storing in glass. The mixing ampules shown in  FIGS. 20   a - 20   f  illustrate both a one-way valve and a frangible interface to provoke the mixing action; however, it has been shown that a one-way valve as shown in  FIG. 20   a  with a small retaining pressure, will be effective for allowing the mixing action in place of a frangible interface as shown in the other figures, i.e.,  FIGS. 20   d ,  20   e  and  20   f . It is also noted that in each of the diagrams shown in  FIGS. 20   a - 20   f , the lyophilized vaccine is shown as a small pill-type member for illustrative purposes; however, in reality, the vaccine will totally fill the space to assure a minimum of air in the compartment. By the same token, while it has been pointed out in earlier discussion that filling the ampules through the front end with liquid vaccine will virtually eliminate the introduction of air into the injectate chamber, the same is not true for the case of pre-filled lyophilized vaccine where a very small amount of air will inevitably exist; consequently, following the mixing action for each of these cases, some form of minimal venting may be needed. 
       FIG. 20   a  illustrates an ampule  1000  that contains lyophilized vaccine  1001  and its diluent, the two being separated by a piston  1002  having a piston head  1004  with a one-way valve  1006  in the direction of an exit nozzle  1018 . The embodiment shown uses umbrella valve  1006  that will open (as shown in dotted lines) when piston  1002  is pulled vertically downward in the figure, wherein a diluent  1010  is forced upward, through the fluid flow path channel, past the valve, and into the lyophilized portion of the chamber for immediate mixing. Piston  1002  has a ring seal  1012  for sealing against fluid flow around the periphery of piston  1002 . The injection is given by first removing a cap  1016  that seals an orifice  1018 , slightly advancing the now sealed piston head  1004  to expel any air, and then fully pushing piston  1002  forward for the injection, wherein umbrella valve  1006  will seal throughput ports  1020  that were used for the mixing action. Cap  1016  shown on exit port  1018  is needed to prevent air from being pulled into ampule  1000  and must be removed to vent air and before an injection is given. Piston  1002  has a piston rod  1022  which is designed so that the MIT injector ram can optionally grab and pull it back during motor reversal when arming occurs. A seal  1024  is provided around an orifice  1026  in ampule  1000  to prevent leakage through orifice  1026 . Alternatively, rod  1022  can be eliminated if a small piece of magnetic material, such as a magnetic disk, is attached to the proximal side  1028  of piston head  1004 . A strong magnet on the injector ram (such as ram  403 ) will make contact with the metal disk when ampule  1000  is inserted; consequently, piston head  1004  will follow the ram in the reverse direction when arming occurs. After an injection, piston  1002  must be locked in the forward position as described earlier (see  FIG. 10   a ), thus allowing a small reverse jog of the ram to separate the two for sanitary disposal. 
       FIG. 20   b  has only lyophilized medication  1001  in the forward or distal part of ampule  1000 . In this case, diluent  1010  is forced into exit nozzle  1018  from a filling station, while at the same time forcing piston  1002  to the proximal end of ampule  1000 . As before, the need for venting is likely, and a rapid forward push on piston  1002  will provoke the injection. 
       FIG. 20   c  again has lyophilized vaccine  1001  in the forward part of ampule  1000 ; however, in this case, an appendage  1030  containing diluent  1010  is attached to exit nozzle  1018  with an appropriate seal  1032 . When an appendage piston  1034  is forced downward, diluent  1010  will flow into the chamber for immediate mixing while simultaneously pushing injector piston  1002  to the proximal end of ampule  1000 . This model is ideally suited to the mixing magazine system described in  FIG. 20   e  below. 
       FIG. 20   d  has both lyophilized vaccine  1001  and diluent  1010  in an appendage  1036  connected to the front end; however, the two are separated by a very thin, frangible interface  1038 , or alternatively, a one-way valve. As soon as pressure is applied to an appendage piston  1040  and interface  1038  is broken, diluent  1010  is forced into the lower chamber to provoke immediate mixing in appendage  1036 , and at the same time, forcing the mixed fluid through nozzle  1018  to force injection piston  1002  to the proximal end of ampule  1000 . This technique is also ideally suited to the mixing magazine of  FIG. 20   e.    
       FIG. 20   e  illustrates a complete mixing/shipping magazine that houses a multitude of pre-filled ampules. This technique could be housed in a lid for the stationary folding magazine and/or the auto-feed magazines described earlier. As such, the force needed to provoke the mixing action will require that the lid be collapsible into the lower stationary portion of the magazine. This type of magazine will ideally serve as a shipping container to further reduce the risk of contamination due to ampule handling, the need for which is virtually zero. The appendage for each ampule is similar to that described for  FIG. 20   d ; however, in this case, the appendage is shown as a bellows assembly. Either type of collapsible appendage is suitable for exercising the techniques described. 
     Still referring to  FIG. 20   e , a filling system  1100  is shown. It has a force transfer member  1102  for collapsing pleated walls  1104  of storage unit  1103  to collapse a chamber  1106  holding diluent  1010  above a frangible interface  1138 , and lyophilized medication  1001  below interface  1138 . This applies to each of N filling stations filled by the operation of member  1102 . Each ampule  1000  has a body portion with piston  1002  having wall engaging seals  1012 . Storage unit  1103  is connected to exit nozzle  1018  having a seal  1032  to prevent leakage. Upon the application of sufficient downward force on member  1102 , the mixing diluent  1010  and lyophilized medication  1001  flow through exit orifice  1018 , forcing piston  1002  downward as shown by the arrow to fill the ampule. A cap could optionally be applied over nozzle or orifice  1018  to close ampule  1000  until an injection is made. 
       FIG. 20   f  illustrates an ampule  1200  that contains a lyophilized vaccine  1202  and its diluent  1204 , and in that regard is similar to  FIG. 20   a . However, in this case, the separation is a very thin, inexpensive frangible barrier  1206  that eliminates the cost of an appendage and/or the piston with the one-way valve. A piston  1210  having an annular seal  1212  is provided. Barrier  1206  is held in place by a sliding seal  1208  which is used to properly locate frangible barrier  1206  in ampule  1200 . Force on ampule piston  1210  will cause barrier  1206  to fracture (or a one-way valve to open) and the mixing action occurs. As soon as mixing is complete and the ampule is full of liquid, a sealing cap  1214  can be removed, whereupon the sliding seal  1208  on barrier  1206  will move with piston  1210  as it reaches barrier  1206  and completes the injection transition through exit port  1216 . 
     While the examples described for the procedures depicted in  FIGS. 20   a - 20   f  illustrate a direct pushing force to provoke the mixing action, a twisting motion for advancing a threaded interface could also be used to facilitate the mixing action. 
     Finally, it should be noted that the conventional jet injector orifices shown in all of the above descriptions can be replaced with a perforator exit nozzle as disclosed in U.S. Pat. No. 6,056,716. Perforator delivery has been extensively experimented with by the inventors over a number of years and has been shown to allow for lower jet pressure, painless delivery because the jet stream begins from just inside the skin, which eliminates the need for the high-speed jet velocity required for crossing the barrier of fully exposed skin. Protection against sharps injury to the healthcare workers remain a concern; however, safety is realized by hiding the perforator before the injection, and having the injector itself destroy the perforator after the injection. Several methods are shown to be effective, one being where the perforator is extended through a tight fitting exit port of a compressible, protective front end that becomes an off axis shield after the perforator is drawn back into the protective housing, i.e., as described for  FIGS. 8   a  and  8   d . In another approach, an off-axis, exit hole on a rotatable disk located at the exit nozzle will automatically rotate after the injection to therefore crush and disable the perforator to the point where it is virtually impossible to do any damage. Another tremendous advantage for using this low-pressure technique is the very low cost for a thin-walled ampule. The inventors have shown over the course of many years of experimentation that pressures of anywhere from 200 to 1000 psi are effective for virtually any type of injection, the preferred pressure depending on the patient, location for the injection and the required depth for the delivery (i.e., intradermal, subcutaneous or intramuscular). Because of this, the use of low cost, thin-walled glass is also possible, since the inventors have also shown that the low cost glass ampules that are readily available will not fracture until exposed to pressures in excess of 1500 psi. Consequently, glass ampules for housing the vaccines for long term storage is a realistic goal for the pre-filled techniques described if perforator delivery is used. 
     The invention has been described in detail, with particular emphasis on the preferred embodiment thereof, but variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains.
A hypodermic injection system particularly for use in mass immunizations having a handpiece with a grasping mechanism for holding ampules filled with injectate, a plunger for driving into the ampule to discharge the injectate in an injection process, an injection spring mechanism for driving the plunger, a motor and/or manual mechanism for cocking the injection spring mechanism, and an ampule ejection mechanism for ejecting ampules after use under control of a release mechanism. Ampules can be loaded, used and ejected without contact by the user of the system or the patient being injected. Also disclosed are a filling station for filling ampules through their injection orifices, and an arming device for setting the injection spring. Ampules are disclosed having a piston which is drivable towards an orifice to discharge injectate through the orifice. Ampules are also disclosed having enlarged proximal portions for easy grasping by the grasping mechanism of the injector. Ampules are further disclosed with separators for mixing lyophilized medication and a diluent. Further disclosed are magazines for holding ampules for sequential use by the hypodermic injector. The disclosed system finds particular use as a mass immunization kit for making numerous injections in the field.