Patent Document

REFERENCE TO PENDING APPLICATION  
       [0001]     The present application is a continuation-in-part of application Ser. No. 10/631,052, filed Jul. 29, 2003, which is a division of application Ser. No. 09/781,000, filed Feb. 9, 2001, now U.S. Pat. No. 6,610,074, which claimed priority from provisional application Ser. No. 60/181,435, filed Feb. 10, 2000 by Albert N. Santilli. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The invention relates to clamps for surgical procedures and, more specifically, to a clamp assembly having the capability to heat tissue that is engaged by the clamp assembly.  
         [0004]     2. Description of the Prior Art  
         [0005]     The invention will be discussed in the context of cardiac surgery, although it is to be understood that the invention has applicability to a wide range of surgical procedures. During the course of cardiac surgery in which cardiac function is arrested, it is necessary to isolate the heart and coronary blood vessels from the remainder of the circulatory system. Circulatory isolation of the heart and coronary blood vessels is usually accomplished by placing a mechanical cross clamp externally on the ascending aorta downstream of the ostia of the coronary arteries, but upstream of the brachiocephalic artery so that oxygenated blood from the cardiopulmonary bypass system reaches the arms, neck, head, and remainder of the body. Using conventional techniques, the sternum is cut longitudinally (a median sternotomy) thereby providing access between opposing halves of the anterior portion of the rib cage to the heart and other thoracic vessels and organs. Alternatively, a lateral thoracotomy is formed, wherein a large incision is made between two ribs and the ribs are retracted. A portion of one or more ribs may be permanently removed to optimize access.  
         [0006]     Regardless of whether a sternotomy or a thoracotomy is performed (both collectively referred to herein as a “gross thoracotomy”), the opening in the chest wall must be large enough to permit a cross clamp to be placed externally on the ascending aorta, thereby isolating the heart and coronary arteries from the remainder of the arterial system. A problem with existing cross clamps is their excessive size. A cross clamp usually includes a clamping portion from which integral actuating handles project. The clamp occupies a relatively large portion of the operative site, thereby requiring that the sternum or ribs be retracted to a greater extent than is desired. This is a significant factor in open-chest surgery, because the trauma caused by creating large openings in the chest wall often entails weeks of hospitalization and months of recuperation time.  
         [0007]     Recently, techniques have been developed to facilitate the performance of cardiac procedures such as heart valve repair and replacement, coronary artery bypass grafting, and the like, using minimally invasive techniques that eliminate the need for a gross thoracotomy. Coronary artery bypass grafting, heart valve repair and replacement, and other procedures can be performed through small incisions or cannulae positioned in the chest wall. In one recently developed technique, a clamp is introduced into the patient&#39;s thoracic cavity through a percutaneous intercostal penetration in the patient&#39;s chest, typically using a trocar sleeve. The clamp is detachably mounted to the distal end of a clamp positioner. After the clamp is positioned around the ascending aorta, the clamp is actuated from outside the patient&#39;s thoracic cavity to squeeze the aorta and partially or completely block fluid flow therethrough. The clamp then is disengaged from the distal end of the clamp positioner and the clamp positioner is removed from the thoracic cavity to provide enhanced access to the region in question.  
         [0008]     Although the referenced device permits cardiac surgery to be conducted with significantly smaller openings formed in the chest wall, there is a concern about the reliability of the clamp and whether a connection can be reestablished between the clamp and the clamp positioner when it is necessary to remove the clamp. A failure of the clamp or the inability to remove the clamp could have disastrous consequences for the patient. An additional concern is that the referenced device employs a clamp made of metal that has no capability to heat tissue with which it comes in contact.  
         [0009]     Despite the advantages of minimally invasive cardiac surgery, certain situations still call for the use of a gross thoracotomy. In such circumstances, there remains a need for an aorta cross clamp that is smaller than existing cross clamps but which is extremely reliable and easy to use. In those cases where minimally invasive surgery is indicated, there is a need for an aorta cross clamp that is easy to apply to the ascending aorta, which is reliable in use, and which can be removed without fail. There also is a need for a clamp that has the capability to heat tissue.  
       SUMMARY OF THE INVENTION  
       [0010]     In response to the foregoing concerns, the present invention provides a new and improved surgical clamp assembly for grasping and heating portions of a patient&#39;s body. The invention includes a clamp having first and second jaws that are movable toward and away from each other, each jaw having a clamping surface that is intended to contact a desired portion of a patient&#39;s body. One or both clamping surfaces can be in the form of, or can include, one or more electrodes. The electrode or electrodes can be energized electrically so as to raise the temperature of the contacted tissue to a desired level. Through the use of suitable electrodes, the clamp can be used to heat, sever, or cauterize tissue.  
         [0011]     The invention can be used with any type of clamp, including conventional scissors-type clamps. The invention also is effective when used with clamps having a removable actuator wherein the clamp is left in or on the patient&#39;s body in a locked position while the actuator is removed from the operative site. In one embodiment, a clamp having movable jaws is provided with a removable actuator having movable handles. Initially, the actuator is connected to the clamp with the jaws in an open position. When the actuator handles are closed, the jaws also will be closed. The clamp is provided with a toothed retainer that prevents the jaws from being opened accidently. The actuator can be detached from the clamp and removed from the operative site, leaving the locked clamp in place. When it is desired to remove the clamp, the actuator can be reattached to the clamp and used to disengage the toothed retainer. The actuator then can be used to spread the jaws in order to permit the clamp to be removed.  
         [0012]     The clamp and the actuator are provided in two forms. In one form, the toothed retainer is engaged and disengaged by movement toward and away from the jaws (“horizontal” movement). In the other form, the toothed retainer is engaged and disengaged by movement generally perpendicular to the jaws (“vertical” movement).  
         [0013]     In another embodiment, a clamp having movable jaws is provided with a slender, flexible, actuator that is not intended to be removed during use. The actuator has a proximal end that defines a handle and a distal end that is connected to the clamp. The jaws are actuated by axial movement of a screw that is connected to the end of a cable included as part of the actuator. The screw passes through a slotted nut that permits non-rotational axial movement of the screw in one direction, but which requires that the screw be rotated in order to move in the opposite direction. A stem having a knob is attached to the proximal end of the cable and extends outwardly from the handle.  
         [0014]     When the knob is pushed inwardly (toward the handle), the stem and the cable are advanced, thereby axially moving the screw and closing the jaws of the clamp. The nut prevents the jaws from being opened inadvertently. When is it necessary to remove the clamp, the knob is rotated. This causes the stem, cable, and screw to be rotated. When the screw is rotated, it is moved axially relative to the nut and pulls the jaws to the open position.  
         [0015]     The present invention provides a surgical clamp that can be used for a variety of surgical procedures, including cardiac surgery during either a gross thoracotomy or a minimally invasive procedure such as a percutaneous intercostal penetration. The ability to heat, sever, or cauterize the tissue contacted by the clamp provides the surgeon with the capability to deal with a wide range of surgical situations that may be encountered. With any embodiment of the invention, the clamp assembly is compact, reliable, and easy to apply and remove. The foregoing and other features and advantages of the invention will be apparent from an examination of the specification and claims that follow, including the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is a perspective view of a surgical clamp assembly according to the invention in which a clamp having electrodes is disposed adjacent an actuator;  
         [0017]      FIG. 2 . is a top plan view of the clamp assembly of  FIG. 1 ;  
         [0018]      FIG. 3 . is a side elevational view of the clamp assembly of  FIG. 1 ;  
         [0019]      FIG. 4  is a view similar to  FIG. 1  showing an alternative surgical clamp assembly according to the invention;  
         [0020]      FIG. 5  is a top plan view of the clamp assembly of  FIG. 4 ;  
         [0021]      FIG. 6  is a side elevational view of the clamp assembly of  FIG. 4 ;  
         [0022]      FIG. 7  is a perspective view of a surgical clamp assembly according to the invention in which a clamp having electrodes is mounted at the end of a flexible actuator;  
         [0023]      FIG. 8  is a view similar to  FIG. 7  in which the components of the clamp assembly have been separated and spaced apart for purposes of clarity of illustration; and  
         [0024]      FIG. 9  is a enlarged plan view, partly in cross-section, of the proximal and distal ends of the actuator of  FIG. 7 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]     The invention can be used with any type of clamp, including conventional scissors-type clamps. The invention also is effective when used with clamps having a removable actuator wherein the clamp is left in or on the patient&#39;s body in a locked position while the actuator is removed from the operative site. The invention will be described in conjunction with clamps having a removable actuator.  
         [0026]     Referring to  FIGS. 1-3 , a surgical clamp assembly according to the invention is indicated by the reference numeral  10 . The clamp assembly  10  is especially adapted for use during a gross thoracotomy, although it can be used for numerous other surgical procedures, if desired. The clamp assembly  10  includes a clamp  12  and an actuator  14 . The clamp  12  has a first jaw  16   a  and a second jaw  18   a . A handle  16   b  having spaced sides is connected to the jaw  16   a . The handle  16   b  includes a formation  16   c  at its end. The formation  16   c  has a slotted opening  16   d . The second jaw  18   a  is similar to the jaw  16   a . A handle  18   b  is connected to the jaw  18   a  and includes a formation  18   c  at its end. A slotted opening  18   d  is provided for the formation  18   c.    
         [0027]     The handle  16   b  is defined by a pair of spaced sides through which the handle  18   b  extends. The handles  16   b ,  18   b  are joined for pivotal movement by a hinge pin  20 . Each of the jaws  16   a ,  18   a  is provided with a plurality of electrodes  22  that form a part of a clamping surface intended to engage a portion of a patient&#39;s body. A pair of wires  23  extend from the electrodes  22  for connection to a source of electrical power (not shown). The electrodes  22  are attached to the respective jaws  16   a ,  18   a  by fasteners  24 . The longitudinal axes of the jaws  16   a ,  18   a  and the handles  16   b ,  18   b  are disposed relative to each other at an angle within the range of about 25-30 degrees, preferably about 27 degrees, when viewed from the side ( FIG. 3 ).  
         [0028]     A curved ratchet bar  26  is connected to the formation  16   c  by means of a spring mounting  27 . The ratchet bar  26  lies in the arc of a circle whose radius is approximately equal to the distance from the hinge pin  20  to the ends of the handles  16   b ,  18   b . The mounting  27  biases the ratchet bar  26  toward the formations  16   c ,  18   c . A plurality of teeth  28  are provided on that portion of the ratchet bar  26  which faces the formations  16   c ,  18   c . A plurality of teeth  30  are provided on the formation  18   c  and face the teeth  28 . The teeth  28 ,  30  are oriented such that they engage each other when the handles  16   b ,  18   b  are attempted to be moved apart, thereby preventing the handles  16   b ,  18   b  from being opened. In effect, the handle  18   b  and the teeth  30  form a pawl that permits closing movement of the jaws  16   a ,  18   a , but which prevents opening movement of the jaws  16   a ,  18   a . When the handles  16   b ,  18   b  (and hence, the jaws  16   a ,  18   a ) are closed, a small gap  32  ( FIG. 2 ) is formed between the handles  16   b ,  18   b.    
         [0029]     The actuator  14  includes first and second handles  34   a ,  36   a  having finger loops  34   b ,  36   b  at the proximal ends thereof. Arms  34   c ,  36   c  are connected to and project from the handles  34   a ,  36   a . A pair of spaced discs  34   d ,  36   d  are disposed at the ends of the arms  34   c ,  36   c . The discs  34   d ,  36   d  are spaced apart a distance slightly greater than the width of the formations  16   c ,  18   c . The discs  34   d ,  36   d  are joined by pins  34   e ,  36   e . The pins  34   e ,  36   e  have a diameter slightly less than that of the slotted openings  16   d ,  18   d.    
         [0030]     The handles  34   a ,  36   a  are joined for pivotal movement by a hinge pin indicated generally by the reference numeral  38 . The actuator  14  includes a third handle  40   a . The handle  40   a  has a finger loop  40   b  at the proximal end thereof. The finger loop  40   b  lies in a plane inclined upwardly at an angle within the range of about 15-20 degrees, preferably about 17 degrees, from the plane in which the handle  40   a  lies. An arm  40   c  is connected to and projects from the handle  40   a . A finger  40   d  extends from the arm  40   c  at a right angle to the longitudinal axis of the arm  40   c . The diameter of the finger  40   d  is slightly less that the width of the space  32 .  
         [0031]     A sleeve  42  is disposed atop the hinge pin  38 . The handle  40   a  extends through the sleeve  42 . An enlarged stop  40   f  is mounted on the arm  40   c . A spring  40   g  is fitted over the arm  40   c  and engages the sleeve  42  and the stop  40   f . The spring  40   g  biases the finger  40   d  away from the sleeve  42  (to the left as viewed in  FIGS. 1-3 ).  
       Operation of the Clamp Assembly  10   
       [0032]     When it is desired to use the clamp  12  to compress a portion of a patient&#39;s body, the handles  34   a ,  36   a  are moved apart (to the dashed line position shown in  FIG. 2 ) so that the pins  34   e ,  36   e  can be engaged with the slotted openings  16   d ,  18   d , respectively. The finger  40   d  will be disposed in that space defined by the handles  16   b ,  18   b , and the ratchet bar  26 . When the finger loops  34   b ,  36   b  are moved toward each other (to the solid line position shown in  FIG. 2 ), the handles  16   b ,  18   b  will be moved toward each other, thereby closing the jaws  16   a ,  18   a . The jaws  16   a ,  18   a  will remain closed due to the interaction of the teeth  28 ,  30 . The actuator  14  can be removed from the now-closed clamp  12  by moving the finger loops  34   b ,  36   b  slightly apart and thereafter pushing the actuator  14  slightly toward the clamp  12 . The actuator  14  then can be moved clear of the clamp  12  by spreading the finger loops  34   b ,  36   b  apart.  
         [0033]     When it is desired to remove the clamp  12 , the foregoing procedure is reversed so that the actuator  14  is reattached to the clamp  12 . If the surgeon&#39;s thumb and middle finger have been used to manipulate the actuator  14 , the surgeon can then place the index finger in the finger loop  40   b  and pull the finger loop  40   b  to the right as viewed in  FIGS. 1-3 , against the bias exerted by the spring  40   g . The finger  40   d  will engage the ratchet bar  26 , causing the teeth  28 ,  30  to be disengaged. Thereafter, the finger loops  34   b ,  34   c  can be spread apart in order to open the jaws  16   a ,  18   a . The clamp assembly  10  then can then be removed from the operative site.  
       A Second Embodiment  
       [0034]     Referring now to  FIGS. 4-6 , an alternative surgical clamp assembly is indicated by the reference numeral  50 . The assembly  50  is especially adapted for use during a gross thoracotomy, although it can be used for numerous other surgical procedures, if desired The clamp assembly  50  includes a clamp  52  and an actuator  54 . The clamp  52  has a first jaw  56   a  and a second jaw  58   a . A curved handle  56   b  is connected to the first jaw  56   a . The handle  56   b  includes an upper, curved bar  56   c  at its end and a lower, curved bar  56   d  that is parallel to, but spaced from, the upper bar  56   c . The second jaw  58   a  is similar to the arm  56   a . A handle  58   b  is connected to the jaw  58   a  and includes an upper, curved bar  58   c  at its end and a lower, curved bar  58   d  that is parallel to, but spaced from, the upper bar  58   c.    
         [0035]     A plurality of teeth  60  are provided on the lower bar  56   d , while a plurality of teeth  62  are provided on the upper bar  58   c . The bars  56   c ,  58   d  do not have any teeth. As can be seen in  FIG. 4 , the bars  56   c ,  56   d ,  58   c ,  58   d  are fitted together so that the teeth  60 ,  62  engage each other when the handles  56   b ,  58   b  are attempted to be moved apart, thereby preventing the handles  56   b ,  58   b  from being opened. In turn, the jaws  56   a ,  58   a  will be prevented from opening. The upper bar  56   c  is spaced at a small distance from the bar  58   c , while the lower bar  56   d  is spaced a small distance from the bar  58   d.    
         [0036]     The handles  56   b ,  58   b  are joined for pivotal movement by a hinge pin  64 . Each of the jaws  56   a ,  58   a  is provided with a plurality of electrodes  65  that form a part of a clamping surface intended to engage a portion of a patient&#39;s body. A pair of wires  66  extend from the electrodes  65  for connection to a source of electrical power (not shown). The electrodes  65  are attached to the respective jaws  56   a ,  58   a  by fasteners  67 . A curved spring  68  is disposed between the handles  56   b ,  58   b  and causes the handles  56   b ,  58   b  to be biased apart. The longitudinal axes of the jaws  56   a ,  58   a  and the handles  56   b ,  58   b  are disposed relative to each other at an angle within the range of about 25-30 degrees, preferably about  27  degrees, when viewed from the side ( FIG. 6 ). When viewed from above ( FIG. 5 ), the bars  56   c ,  56   d ,  58   c ,  58   d  lie in the arc of a circle whose radius is approximately equal to the distance from the hinge pin  64  to the ends of the handles  56   b ,  58   b.    
         [0037]     The actuator  54  includes first and second handles  70   a ,  72   a  having finger loops  70   b ,  72   b  at the proximal ends thereof. A pair of opposed shells  70   c ,  72   c  are connected to the handles  70   a ,  72   a , respectively. The shells  70   c ,  72   c  are of a size and shape to receive the curved handles  56   b ,  58   b , including the upper and lower curved bars  56   c ,  58   c ,  56   c ,  58   d . The handles  70   a ,  72   a  are joined for pivotal movement by a hinge pin indicated generally by the reference numeral  74 . When the handles  70   a ,  72   a  (and, hence, the shells  70   c ,  72   c ) are closed, a small gap  75  ( FIG. 5 ) is formed between the shells  70   c ,  72   c.    
         [0038]     The actuator  54  includes a third handle  76   a  having a finger loop  76   b  at the proximal end thereof. The handle  76   a  has a generally ogee-shaped distal end  76   c  that includes an axially extending lower portion  76   d . The lower portion  76   d  is adapted to fit into the gap  75  between the closed shells  70   c ,  72   c  and engage the lower curved bar  58   d.    
         [0039]     The actuator  54  includes a formation  78  which is connected to the hinge  74 . A pair of spaced tabs  80  are included as part of the formation  78 . A hinge pin  82  extends through the tabs  80  and the handle  76   a . A spring  84  is disposed intermediate the upper surface of the formation  78  and the underside of the handle  76   a . The spring  84  biases the handle  76   a  away from the first and second handles  70   a ,  72   a  to that position shown by the solid lines in  FIG. 6 .  
       Operation of the Clamp Assembly  50   
       [0040]     When it desired to use the clamp  52  to compress a portion of a patient&#39;s body, the shells  70   c ,  72   c  are disposed about the ends of the curved handles  56   b ,  58   b  in the open position. As the handles  70   a ,  72   a  are moved toward each other, the jaws  56   a ,  58   a  will be moved to the solid line position in  FIG. 5 . After the handles  70   a ,  72   a  have been moved apart and the shells  70   c ,  72   c  have been removed from the handles  56   b ,  58   b , the clamp  52  will remain in the closed position shown by the solid lines in  FIG. 5  due to the engagement between the opposed teeth  60 ,  62 .  
         [0041]     When it is desired to remove the clamp  52 , the foregoing procedure is reversed and the handle  76   a  is pressed towards the handles  70   a ,  72   a . The lower portion  76   d  will be pivoted into contact with the lower curved bar  58   d . Continued movement of the handle  76   a  will cause the upper curved bar  56   d  to engage the underside of the upper walls that define the shells  70   c ,  72   c . Thereafter, continued movement of the handle  76   a  will cause the bars  58   c ,  56   d  to be moved relative to each other such that the teeth  60 ,  62  become disengaged. Under the influence of the spring  68 , the handles  56   b ,  58   b  (and, hence, the jaws  56   a ,  58   a ) will be moved apart as the handles  70   a ,  72   a  are moved apart from each other. After the jaws  56   a ,  58   a  have been moved enough to release their grip on the aorta, the clamp  52  and the actuator  54  can be retracted from the operative site.  
       A Third Embodiment  
       [0042]     Referring now to  FIGS. 7-9 , another surgical clamp assembly is indicated by the reference numeral  90 . The assembly  90  is especially adapted for use during minimally invasive cardiac surgery, although it can be used for numerous other surgical procedures, if desired. The assembly  90  includes a clamp  92  and an actuator  94 . The clamp  92  has a cylindrical base  96  with a bore therethrough. A first jaw  98  is rigidly connected to the cylindrical base. A second jaw  100  is pivotally connected to the cylindrical base  96 . The connection is established by a slot  102  formed in the first jaw  98 . A hinge pin  104  extends through the jaws  98 ,  100 . Each of the jaws  98 , 100  is provided with a plurality of electrodes  104  that form a part of a clamping surface intended to engage a portion of a patient&#39;s body. A pair of wires  106  extend from the electrodes  104  for connection to a source of electrical power (not shown). The electrodes  104  are attached to the respective jaws  98 , 100  by fasteners  108 .  
         [0043]     A screw  110  is disposed within the bore. A screw  110  is a so-called quick advance screw having coarse, tapered threads. A slotted nut  112  is connected to the cylindrical base  96  at that end opposite the jaws  98 , 100 . A link  114  is connected to the jaw  100 . The connection is established by a slot  116  formed in the jaw  100  and a pin  118  that is connected to the link  116  which extends through the slot  116 . The link  114  is rotatably connected to the screw  110 . A drive connector  120  having a plurality of longitudinally extending keyways is connected to the other end of screw  110 .  
         [0044]     The actuator  94  includes a flexible housing  122 . A fitting  124  is connected to the proximal end of the housing  122 . A cylindrical, hollow handle  126  is connected to the fitting  124 . A pair of finger loops  128  extend from opposite sides of handle  126 . A fitting  130  is connected to the distal end of the housing  122 . The fitting  124  is releasably connected to the handle  126 , while the fitting  130  is releasably connected to the cylindrical base  96 . Although the fittings  124 , 130  can be disconnected for purposes of cleaning and sterilization, it is expected that they will remain connected as shown in  FIG. 7  during the course of a surgical procedure.  
         [0045]     An elongate flexible cable  132  extends through the housing  122 . A cylindrical stem  134  is connected to the proximal end of the cable  132 . A knurled knob  136  is disposed at the end of the stem  134 . A splined drive member  138  is connected to the distal end of the cable  132 . The splines on the drive member  138  engage the keyways in the drive connector  120  so as to establish a driving connection. As will be apparent from an examination of  FIG. 9 , the drive member  138  and the connector  120  can be moved axially relative to each other.  
       Operation of the Clamp Assembly  90   
       [0046]     Starting from the position shown  FIG. 7 , the clamp  92  can be actuated to cause the jaws  98 , 100  to clamp a portion of a patient&#39;s body by pushing the stem  134  toward the handle  126  (from the full line position in  FIG. 9  to the dashed line position in  FIG. 9 ). When the handle  126  is moved in this manner, the cable  132  is moved within the housing so that axial force is applied to the connector  120  and, hence, to the screw  110 . Due to the orientation of the screw threads relative to the nut  112 , the screw  110  will be moved axially, thereby causing the jaw  100  to be pivoted toward the jaw  98 . Although the screw  110  can be advanced toward a jaw-closed position without rotation, it cannot be retracted without rotation for two reasons: (1) if the cable  132  is pulled out of the housing  122 , the drive member  138  will be disconnected from the drive connector  120 , as shown in  FIG. 9 , and (2) the nut  112  will engage the threads of the screw  110  so as to prevent retraction of the screw  110 .  
         [0047]     When it is desired to loosen the jaws  98 , 100  in order to remove the clamp  92  from the clamped portion of the patient&#39;s body, it is necessary to rotate the knob  136  so that the stem  134 , cable  132 , drive member  138 , connector  120 , and screw  110  all are rotated. When the screw  110  is rotated relative to the nut  112 , the screw  110  will be retracted from the bore in the base  96 , thereby causing the jaw  100  to be pulled toward a jaw-open position. After sufficient movement of the jaw  100  has occurred, the clamp  92  can be removed from the operative site.  
         [0048]     The electrodes  22 ,  66 ,  104  can be any type of heating element capable of heating body tissues to a desired temperature. Such electrodes can operate by resistance heating, radio frequency heating, ultrasonic heating, or any other technique that can be used to heat electrodes or tissue that is in contact with the electrodes  22 ,  66 ,  104 . It is possible to use the electrodes  22 ,  66 ,  104  to cauterize tissue, sever tissue, or merely heat tissue to an above-body temperature for therapeutic purposes.  
         [0049]     Electrodes that are suitable for surgical purposes and which operate on different principles are commercially available from a number of sources. One such type of suitable electrode is a monopolar or bipolar electrode that is used for electro-surgery and which is available from Valleylab, 5920 Longbow Drive, Boulder, Colo. 80301. Ceramic heating elements made from barium titanate are believed to be capable of being used for surgical or therapeutic purposes and are available from Dekko Medical Devices, Kendaliville, Ind. 46755. Other suitable types of electrodes are commercially available.  
         [0050]     It is possible for the various components of the invention to be modified and still produce a satisfactory product. For example, and without limitation as to the type of changes that are within the scope of the invention, the embodiment of  FIGS. 1-3  could be provided as a third class lever similar to the embodiment of  FIGS. 7-9 , that is, the handles  16   b ,  18   b  could be eliminated and the ratchet bar  26  and the formations  16   c ,  18   c  could be positioned between the hinge pin  20  and the inserts  22 . In this case, the ratchet bar  26  would be on the top or bottom of the jaws  16   a ,  18   a  or it would extend through an opening formed in one of the jaws  16   a ,  18   a . The embodiments of  FIGS. 4-6  could be reconfigured similarly. The embodiment of  FIGS. 7-9  could be provided in the form of a first class lever by connecting a handle to the second jaw  100 , in a manner similar to the embodiments of  FIGS. 1-3  and  4 - 6 .  
         [0051]     Although the invention has been described in its preferred form with a certain degree of particularity, it will be understood that the present disclosure of the preferred embodiment has been made only by way of example, and that various changes may be resorted to without departing from the true spirit and scope of the invention as hereinafter claimed. It is intended that the patent shall cover, by suitable expression in the appended claims, whatever degree of patentable novelty exists in the invention disclosed.

Technology Category: a