the present invention is directed toward a novel method for measuring length of a region of plaque or blockage in a blood vessel . the present invention employs a measuring device external to the patient ( extracorporeal ) for measuring the length of a vascular lesion that eliminates the use of radio - markers on the wire itself . fig1 depicts one embodiment of the device of the present invention for measuring length of a lesion or blockage in a blood vessel . in one embodiment , device 100 comprises a first fixed horizontal ruler 101 and a second fixed horizontal ruler 102 and vertical sliding sleeve 103 . in one embodiment , first and second horizontal rulers 101 and 102 , respectively , are marked in units of length . it should be understood to those of ordinary skill in the art that the ruler markings are scaled , or placed at fixed intervals , so that they can be used as a reference standard in measurement . for example , and not limited to such example , when the horizontal rulers are used to measure arterial blockage , it is preferred that the units of length marked are in millimeters , with additional markings for every tenth of a millimeter . these markings serve as a visual reference representing the displacement that occurs when the vertical sliding sleeve 103 slides over the horizontal rulers 101 , 102 during the measurement of blockage . in one embodiment , first horizontal ruler 101 and second horizontal ruler 102 are parallel to each other , and thus , lie in the same plane , and are also co - planar with , and separated by , a guide wire 106 , as shown in fig1 . in another embodiment , the horizontal rulers 101 , 102 are parallel to each other but not separated by the guide wire 106 , permitting the device to rest more comfortably on the patient &# 39 ; s leg ( thigh platform ), usually 40 - 50 cm from the groin . this embodiment is illustrated , and described in further detail , with respect to fig3 . the device 100 also comprises a torquer 105 , at proximal end 120 ( the end that is close to the clinician ), which is used to 1 ) set a reference point a for the measurement and 2 ) optionally control the sliding movement of the vertical sleeve 103 . the torquer 105 also allows for controlling ( or limiting ) the movement of guide wire 106 . the vertical sleeve 103 is , in one embodiment , provided with a slot 107 a to allow the guide wire 106 to pass through unobstructed and the torque is , in one embodiment , provided with a slot 107 b to allow the guide wire to pass through . using the torquer 105 , guide wire 106 can be advanced out of the distal end 121 ( the end that is close to the patient ) of a catheter 108 into the patient &# 39 ; s coronary artery to reach the affected area or blockage in the artery . one of ordinary skill in the art would appreciate that device 100 may be used with any conventional catheterization assembly 108 . measurement device 100 further comprises an adapter , a ring , band , rubberized band , rubberized ring , or band - like member 109 ( shown in more detail in fig2 ) for coupling the measurement device to a standard catheterization assembly 108 . a suitable adapter 110 used in cardiac catheterization procedures , such as a touhy - borst y - adapter with side arm and valve , couples with the ring - like member 109 , to attach the device 100 to the catheter assembly 108 . the torquer 105 is a standard piece of equipment that can be used to manipulate the guide wire externally ( from outside the patient ). the torquer 105 comprises a screw mechanism ( not shown ), which when tightened , acts to fix the movement of guide wire 106 . thus , when the practitioner tightens the screw on the torque 105 , fixed reference point a is created . it should be noted herein , and will be described in further detail later , that the torquer can be tightened at any point to create fixed reference point a , including , but not limited to a tip , transition between visible / invisible regions , markers , and the like . fig2 is a perspective view illustrating the measurement mechanism 200 of the device of the present invention . a practitioner is able to see x - ray images of the heart after contrast material is introduced into the bloodstream of the patient . in order to use the measurement device of the present invention , the practitioner passes a guide wire 206 through the blood vessel of concern , which can be viewed by x - ray imaging . as the guide wire 206 passes through , the practitioner can decide upon a reference point in the x - ray image of the blood vessel , to mark the starting point of the region of interest . the reference point can be any discernable part of the image such as the tip of guide wire , transition between a visible and an invisible part in the image , a marker on the wire , and the like . referring to fig2 , as soon as the guide wire 206 reaches this reference point , the practitioner tightens the torquer 201 . this acts to acts to a ) create reference point a , 210 and b ) fix the movement of the guide wire ( shown in fig1 ). the point on the horizontal rulers 203 and 204 where the vertical sliding sleeve 202 is positioned upon tightening the torque is referred to as fixed reference point a 210 . this point is marked and / or noted by the practitioner . it should be noted that the practitioner can mark the position of the vertical sliding sleeve 202 by any suitable marking means , including a clip , ink marker , label , or the like . thereafter , the torquer is operated such that the guide wire is advanced further through the lesion . thus , as soon as the torquer is fixed to create a reference point a , and the position of the sliding sleeve 202 is marked , the movable portion of the device is pushed forward . in one embodiment , the movable portion comprises both the torquer and vertical sliding sleeve . in one embodiment , the torquer and vertical sliding sleeve are independently movable . the space between the two horizontal rulers 203 and 204 is large enough to allow for easy manipulation of the torquer 201 . as the guide wire advances , the slidable vertical sleeve 202 is also pushed forward along with the guide wire over the two horizontal rulers 203 and 204 . it should be noted that , in one embodiment , the torquer 201 is used to push vertical sliding sleeve forward . in another embodiment , the practitioner pushes the vertical sliding sleeve forward , as necessary , to mark points on the rulers . when the guide wire 206 reaches at the end of lesion or blockage , the practitioner again tightens the torquer 201 , to fix the movement of guide wire ( not shown ). the position of the vertical ruler 202 on the horizontal rulers 203 and 204 determines point b 220 . the practitioner marks the point b 220 , and the distance 225 between point a 210 and point b on the horizontal rulers 203 and 204 provides a measure of the length of the lesion or blockage in the blood vessel . thus in the present invention , the start point and end point for measurement are based on the torque point , that is the fixed point created using the torque mechanism . one of ordinary skill in the art would appreciate that the mechanism for measuring length as illustrated in the present invention may not only be employed to measure a blockage in the coronary artery , but can be used to measure the length of any region of interest in a blood vessel through which a guide wire may be passed . in one embodiment , the torquer is integrated with a housing in such a manner that it reduces the movement of the guide wire . this serves to improve the precision of measurement as any undesirable small movement or shake in movement of the wire is prevented . this embodiment is illustrated in fig3 . referring to fig3 , the device 300 comprises a housing 301 , having a distal end 301 a and a proximal end 301 b , where the distal end 301 a is closest to the catheterization assembly 307 and the proximal end 301 b comprises a torquer 303 . further , distal end 301 a of housing 301 further comprises an opening 320 for guide wire 302 to be inserted through . device 300 further comprises at least one vertical sliding sleeve 310 , and preferably two vertical sliding sleeves 310 , attached to and thus , integrated with , housing 301 at its distal end 301 a . the device 300 further comprises a first horizontal measurement ruler 304 and a second horizontal measurement ruler 305 , which are parallel to each other , and which preferably rest on the patient &# 39 ; s thigh 306 . vertical sliding sleeves 310 are perpendicular to , and slide over horizontal rulers 304 and 305 . vertical sliding sleeves 310 are used to mark reference points , and thus , provide a measurement of the distance 311 travelled by the guide wire 302 between the two marked reference points , and hence the length of the region of interest . horizontal rulers 304 and 305 are attached to , at their distal end 321 , a ring or collar connector 322 . as mentioned previously , the measurement device 300 of the present invention is coupled to a catheterization assembly 307 , at the distal end 321 of the horizontal rulers by means of attaching a ring or collar connecter 322 to a suitable y - adapter 309 . the catheter 307 provides entry for the guide wire 302 into the patient at point 308 . fig4 is a flow chart illustrating operational steps of one embodiment of the present invention . now referring to fig4 , in step 402 , a point of entry is created in a patient via a standard catheter . in step 404 , the measurement device of the present invention is coupled to the standard catheterization assembly using , as described above , a ring or band - like member . a suitable adapter used in cardiac catheterization procedures , such as a touhy - borst y - adapter with side arm and valve , couples with the ring - like member to attach the device to the catheter assembly . in step 406 , the practitioner injects the patient artery with a contrast material so that he can simultaneously view x - ray images of the heart . in order to use the measurement device of the present invention , in step 408 , the practitioner passes a guide wire through the blood vessel of concern , which can be viewed by the x - ray imaging . as the guide wire passes through , the practitioner , in step 410 , decides upon a reference point in the x - ray image of the blood vessel , to mark the starting point of the region of interest . the reference point can be any discernable part of the image such as the tip of guide wire , transition between a visible and an invisible part in the image , a marker on the wire , and the like . as soon as the guide wire reaches this reference point , in step 412 , the practitioner tightens the torque to a ) create reference a point a and b ) fix the movement of the guide wire ( shown in fig1 ). in one embodiment , the torque moves the vertical sliding sleeve into position and thus , the point on the horizontal rulers where the vertical sliding sleeve is positioned upon tightening the torque is referred to as fixed reference point a . in another embodiment , the practitioner may optionally move the vertical sliding sleeve to the appropriate position after tightening the torque . this is especially convenient in the case where the measurement is being made in reverse , that is , from the end of the region of interest to the beginning of the region of interest , or as the guidewire is being removed from the patient . thus , the torquer is not required to move the vertical sliding sleeve . fixed reference point a is marked and / or noted by the practitioner , in step 414 . it should be noted that the practitioner can mark the position of the vertical sliding sleeve by any suitable marking means , including a clip , ink marker , label , or the like . thereafter , the torquer is operated such that the guide wire is advanced further through the lesion . thus , as soon as the torquer is fixed to create reference point a , and the position of the vertical sliding sleeve is marked and / or recorded , the torquer is loosened in step 416 , to allow the movable portion of the device to be pushed forward in step 418 . as the guide wire is advanced using the torquer , the slidable vertical sleeve is also pushed forward along with the guide wire over the twin horizontal rulers . it should be noted that , in one embodiment , the torquer is used to push the vertical sliding sleeve forward . in another embodiment , the practitioner pushes the vertical sliding sleeve forward , as necessary , to mark points on the rulers . when the guide wire reaches the end of lesion or blockage , the practitioner again tightens the torquer in step 420 , to fix the movement of guide wire ( not shown ). the position of the vertical ruler on the horizontal rulers determines point b . the practitioner marks point b in step 422 . the practitioner then calculates , in step 424 , the distance between point a and point b on the horizontal rulers to provide a measure of the length of the lesion or blockage in the blood vessel . the device of the present invention can be used to measure the length of a region of interest in a blood vessel , in case when the guide wire is going in as well as when it is coming out . this is because the measurement relies on an external reference point , which is the fixed point created using the torquer as described above . the device or product of the present invention is designed to be disposable in order to help maintain better hygiene in the catheterization procedures where it is to be used . further , the device can be easily coupled to existing catheterization mechanisms , and is designed to conveniently snap in and out of the existing side arm and valve of the adapters commonly used in cardiac procedures . this lends additional operational simplicity to the device of the present invention . while there has been illustrated and described what is at present considered to be a preferred embodiment of the present invention , it will be understood by those skilled in the art that various changes and modifications may be made , and equivalents may be substituted for elements thereof without departing from the true scope of the invention . in addition , many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the central scope thereof . therefore , it is intended that this invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out the invention , but that the invention will include all embodiments falling within the scope of the appended claims .