Patent Publication Number: US-11020172-B2

Title: Apparatus for performing an electrosurgical procedure

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. patent application Ser. No. 14/887,529, filed on Oct. 20, 2015, now U.S. Pat. No. 10,085,795, which is a divisional application of U.S. patent application Ser. No. 13/113,231, filed on May 23, 2011, now U.S. Pat. No. 9,161,807, the entire contents of each of which are hereby incorporated herein by reference. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to an apparatus for performing an electrosurgical procedure. More particularly, the present disclosure relates to an electrosurgical apparatus including an end effector assembly having a pair of jaw members that provide a mechanical advantage at the end effector. 
     Description of Related Art 
     Electrosurgical instruments, e.g., electrosurgical forceps (open or closed type), are well known in the medical arts and typically include a housing, a handle assembly, a shaft and an end effector assembly attached to a distal end of the shaft. The end effector includes jaw members that are configured to manipulate tissue (e.g., grasp and seal tissue). Typically, the electrosurgical forceps utilizes both mechanical clamping action and electrical energy to effect hemostasis by heating the tissue and blood vessels to coagulate, cauterize, seal, cut, desiccate, and/or fulgurate tissue. Typically, one or more driving mechanisms, e.g., a drive assembly including a drive element, is utilized to cooperate with one or more components operatively associated with the end effector to impart movement to one or both of the jaw members. 
     To facilitate moving the jaw members from an open position for grasping tissue to a closed position for clamping tissue (or vice versa) such that a consistent, uniform tissue effect (e.g., tissue seal) is achieved, one or more types of suitable devices may be operably associated with the electrosurgical forceps. For example, in some instances, one or more cam members, e.g., a cam pin, may operably couple to the drive element, e.g., a drive rod, wire, cable, etc., and operably couple to a cam slot that is operably associated with one or both of the jaw members. Typically, the cam slots are operably disposed on proximal ends of the jaw members. In certain instances, the proximal ends of the jaw members are configured to extend outside of the shaft profile. In the extended position, the proximal ends of the jaw members are commonly referred to as “flags.” 
     In certain instances, the shaft may bend or deform during the course of an electrosurgical procedure. For example, under certain circumstances, a clinician may intentionally bend or articulate the shaft to gain desired mechanical advantage at the surgical site. Or, under certain circumstances, the surgical environment may cause unintentional or unwanted bending or flexing of the shaft, such as, for example, in the instance where the shaft is a component of a catheter-based electrosurgical forceps. More particularly, shafts associated with catheter-based electrosurgical forceps are typically designed to function with relatively small jaw members, e.g., jaw members that are configured to pass through openings that are 3 mm or less in diameter. Accordingly, the shaft and operative components associated therewith, e.g., a drive rod, are proportioned appropriately. That is, the shaft and drive rod are relatively small. 
     As can be appreciated, when the shaft is bent or deformed (either intentionally or unintentionally) any forces or frictional losses at the distal end of the shaft including those caused by the “flags” extending through the shaft profile and having to displace the flexible insulation may be transferred to the drive rod, drive element, and/or a spring operably associated with the drive assembly, which, in turn, may diminish, impede and/or prevent effective transfer of the desired closure force that is needed at the jaw members. Moreover, the frictional losses may also lessen the operative life of the spring, which, in turn, ultimately lessens the operative life of the electrosurgical instrument. 
     SUMMARY 
     The present disclosure provides an endoscopic forceps. The endoscopic forceps includes a housing having a shaft that extends therefrom and defines a longitudinal axis therethrough. An end effector assembly is operatively connected to a distal end of the shaft and includes a pair of first and second jaw members. The first and second jaw members are pivotably coupled to one another. The first and second jaw members are movable relative to one another from an open position, wherein the first and second jaw members are disposed in spaced relation relative to one another, to a clamping position, wherein the first and second jaw members cooperate to grasp tissue therebetween. A drive mechanism includes a driving structure. A link assembly includes two or more links that are operably coupled to each other and the driving structure. The two or more links are operably coupled to respective ones of the first and second jaw members at proximal ends thereof. The proximal ends of the first and second jaw members each includes a stop member that is configured to contact the respective one of the at least two links. The stop members of the first and second jaw members include a generally slanted trailing edge that is configured to contact a leading edge of the respective one of the at least two links as the at least two links transition past vertical such that the first and second jaw members are releasably maintained in the clamping position. 
     The present disclosure provides endoscopic forceps. The endoscopic forceps includes a housing having a shaft that extends therefrom and defines a longitudinal axis therethrough. The shaft has a cam operably disposed thereon adjacent a distal end thereof. An end effector assembly is operatively connected to a distal end of the shaft adjacent the cam and includes a pair of first and second jaw members pivotably coupled to one another. One or both of the first and second jaw members are movable relative to the other jaw member from an open or neutral position, wherein the first and second jaw members are disposed in spaced relation relative to one another, to a clamping position, wherein the first and second jaw members cooperate to grasp tissue therebetween. A drive mechanism includes a driving structure. A link assembly includes two or more links. A top portion of one of the links operably couples to a bottom portion of the other link. The top and bottom portions of the links are operably coupled to each other and the driving structure via a pivot pin. The two or more links are operably coupled to respective ones of the first and second jaw members at proximal ends thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       Various embodiments of the present disclosure are described hereinbelow with references to the drawings, wherein: 
         FIG. 1  is a side, perspective view of an endoscopic bipolar forceps showing an end effector assembly including jaw members according to an embodiment of the present disclosure; 
         FIG. 2  is a side, perspective view of the endoscopic bipolar forceps depicted in  FIG. 1  illustrating internal components associated with a handle assembly associated with the endoscopic bipolar forceps; 
         FIG. 3  is a schematic view of the jaw members depicted in  FIGS. 1 and 2  illustrating a distal end of a driving structure operably coupled to the jaw members; 
         FIG. 4  is a schematic view illustrating a distal end of the driving structure depicted in  FIG. 3  according to another embodiment of the present disclosure; 
         FIG. 5  is a schematic view illustrating an end effector assembly including jaw members according to another embodiment of the present disclosure; 
         FIG. 6  is a schematic view illustrating an end effector assembly including jaw members according to yet another embodiment of the present disclosure; 
         FIG. 7  is a schematic view illustrating an end effector assembly including jaw members according to still another embodiment of the present disclosure; 
         FIG. 8  is a schematic view illustrating an end effector assembly including jaw members according to still yet another embodiment of the present disclosure; 
         FIG. 9  is a schematic view illustrating an end effector assembly including jaw members according to yet another embodiment of the present disclosure; 
         FIG. 10  is a schematic view illustrating an end effector assembly including jaw members according to still yet another embodiment of the present disclosure; and 
         FIG. 11  is a schematic view illustrating an end effector assembly including jaw members according to yet another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Detailed embodiments of the present disclosure are disclosed herein; however, the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. 
     In the drawings and in the descriptions that follow, the term “proximal,” as is traditional, will refer to an end which is closer to the user, while the term “distal” will refer to an end that is farther from the user. 
     With reference to  FIGS. 1 and 2 , an illustrative embodiment of an electrosurgical apparatus, e.g., a bipolar forceps  10  (forceps  10 ) is shown. Forceps  10  is operatively and selectively coupled to an electrosurgical generator (not shown) for performing an electrosurgical procedure. As noted above, an electrosurgical procedure may include sealing, cutting, cauterizing coagulating, desiccating, and fulgurating tissue all of which may employ RF energy. The electrosurgical generator may be configured for monopolar and/or bipolar modes of operation and may include or be in operative communication with a system that may include one or more processors in operative communication with one or more control modules (not shown) that are executable on the processor. The control module may be configured to instruct one or more modules to transmit electrosurgical energy, which may be in the form of a wave or signal/pulse, via one or more cables (e.g., an electrosurgical cable  310 ) to the forceps  10 . 
     Forceps  10  is shown configured for use with various electrosurgical procedures and generally includes a housing  20 , an electrosurgical cable  310  that connects the forceps  10  to the electrosurgical generator, a rotating assembly  80  and a trigger assembly  70 . For a more detailed description of the rotating assembly  80 , trigger assembly  70 , and electrosurgical cable  310  (including line-feed configurations and/or connections), reference is made to commonly-owned U.S. patent application Ser. No. 11/595,194 filed on Nov. 9, 2006, now U.S. Patent Publication No. 2007/0173814. 
     With continued reference to  FIGS. 1 and 2 , forceps  10  includes a shaft  12  that has a distal end  14  configured to mechanically engage an end effector assembly  100  operably associated with the forceps  10  and a proximal end  16  that mechanically engages the housing  20 . 
     A cam slot  13  of suitable configuration is positioned at the distal end  4  of the shaft  12  and is configured to receive a pivot pin  111  therein such that the pivot pin  111  may translate therein ( FIGS. 1-4 ). In the illustrated embodiment, the cam slot  13  is defined through the shaft  12 . 
     A resilient member in the form of a compression spring  15  is provided at the distal  14  end of the shaft  12 . In particular, the spring  15  is grounded to an internal wall of the shaft  12  and couples to the pivot pin  111  via a one or more suitable coupling methods ( FIGS. 3 and 4 ). In the illustrated embodiment, a spring coupler  17  operably couples the pivot pin  111  to the spring  15 . 
     Handle assembly  30  includes a fixed handle  50  and movable handle  40  ( FIGS. 1 and 2 ). In one particular embodiment, fixed handle  50  is integrally associated with housing  20 . Movable handle  40  is movable relative to fixed handle  50  for effecting movement of one or more components, e.g., driving structure  133 , operably associated with a drive mechanism  130  ( FIGS. 2 and 3 ). Handle assembly  30  including movable handle  40  may be configured such that proximal movement of the movable handle  40  “pushes” the driving structure  133 , which, in turn, imparts movement of the jaw members  110  and  120  from a normally open position ( FIG. 1 ) to closed or clamping position ( FIGS. 2 and 3 ). Alternatively, handle assembly  30  including movable handle  40  and drive mechanism  130  may be configured such that proximal movement of the movable handle  40  “pulls” the driving structure  133 , which, in turn, imparts movement of the jaw members  110  and  120  from a normally an open position ( FIG. 1 ) to a closed position, wherein the jaw members  110  and  120  are configured to grasp tissue therebetween. 
     Drive mechanism  130  is in operative communication with movable handle  40  (see  FIGS. 1 and 2 ) for imparting movement of one or, in some instances, both of the jaw members  110 ,  120  of end effector assembly  100 . More particularly, one or more suitable mechanical interfaces, e.g., a linkage interface, gear interface, or combination thereof operably couples the movable handle  40  to the drive mechanism  130 . In the embodiment illustrated in  FIGS. 1-3 , proximal movement of the movable handle  40  moves the jaw members  110  and  120  toward each other from the normally open position to the clamping position. 
     Driving structure  133  is configured such that distal movement thereof causes the jaw members  110  and  120  to move from the open position ( FIG. 1 ) to the clamping position ( FIGS. 2 and 3 ) and vice versa. To this end, driving structure  133  may be any suitable driving structure or mechanism including but not limited to a wire, rod, cable, band, etc. In the illustrated embodiment, driving structure  133  is a substantially flexible drive rod  133  of suitable proportion that is dimensioned to translate within the shaft  12  (see  FIGS. 1-3 ). Drive rod  133  is dimensioned such that the drive rod  133  does not to “buckle” or “kink” when the drive rod  133  is moved distally and/or proximally within the shaft  12 . Drive rod  133  includes a proximal end (not explicitly shown) that is in operative communication with the movable handle  40 . 
     With reference to  FIG. 3 , a distal end  135  of the drive rod  133  operably couples to the end effector  100  and/or jaw members  110  and  120 . More particularly, and in the embodiment illustrated in  FIG. 3 , a pivot pin  21   a  (or rivet, fastener, living-hinge or the like) operably couples the distal end  135  of the drive rod  133  to a link assembly  19 . 
     Link assembly  19  is an over-the-center link type and includes two or more links. In the embodiment illustrated in  FIG. 3 , link assembly  19  includes two links  19   a  and  19   b . Links  19   a  and  19   b  are pivotably coupled to each other via one or more suitable coupling methods. More particularly, pivot pin  21   a  operably couples the distal end  135  of the drive rod  133  to a top portion of the link  19   a  and a bottom portion of the link  19   b . Link assembly  19  including links  19   a  and  19   b  serves to latch the jaw members  110  and  120  in the closed or clamping position when the links  19   a  and  19   b  and/or pivot pin  21   a  moves past a center point of the link assembly  19 . That is, as the links  19   a  and  19   b  transition past vertical, the links  19   a  and  19   b  are configured to contact and/or releasably engage the jaw members  110  and  120  (or component associated therewith) of the end effector such that the jaw members  110  and  120  remain in the closed or clamping position, described in greater detail below. As can be appreciated, having the link assembly  19  serve as a latch may eliminate the need for a separate latching device in the housing  20  and/or handle assembly  30  as is typically utilized with conventional forceps. Moreover, the link assembly  19  provides an additional mechanical advantage when closing the jaw members  110  and  120  at the beginning of a closing or clamping stroke (i.e., when the movable handle  40  is moved proximally). That is, due to the geometries of the links  19   a  and  19   b , the force at the jaw members  110  and  120  is controlled by the geometry and stiffness of the links  19   a  and  19   b  and/or the jaw members  110  and  120  (or operative components associated therewith). 
     A top portion of the link  19   b  operably couples to jaw member  120 . More particularly, a pivot pin  21   b  operably couples the top portion of the link  19   b  to a proximal end  127   a  of the jaw member  120  ( FIG. 3 ). Likewise, a pivot pin  21   c  operably couples a top portion of the link  19   a  to the jaw member  110  ( FIG. 3 ). 
     End effector assembly  100  is illustrated operably disposed at the distal end  14  of the shaft  12  ( FIGS. 1-3 ). End effector assembly  100  includes opposing jaw members  110  and  120  that mutually cooperate to grasp, seal and, in some cases, divide large tubular vessels and large vascular tissues. As noted above, in the illustrated embodiment, jaw members  110  and  120  are movable relative to each other. Jaw members  110 ,  120  are operatively and pivotably coupled to each other via a pivot pin  111  and are located adjacent the distal end  14  of shaft  12 . Electrically conductive seal plates  118  and  128  are operably supported on and secured to respective distal ends  117   b  and  127   b  of jaw housings  117  and  127 . Jaw members  110  and  120  including respective jaw housings  117  and  127 , and operative components associated therewith, may be formed from any suitable material, including but not limited to metal, metal alloys, plastic, plastic composites, ceramics, ceramic composites, and so forth. 
     Jaw housing  127  and  117  of the respective jaw members  110  and  120  are substantially identical to each other. In view thereof, the operative features of jaw housing  127  are described in detail, and only those features that are unique to jaw member  110  are described hereinafter. 
     With continued reference to  FIG. 3 , an embodiment of jaw housing  127  is illustrated. Jaw housing  127  includes distal end  127   b  that is configured to operably support seal plate  128  and proximal end  127   a  that operably couples to the distal end  14  of shaft  12  and to the top portion of the link  19   b . Proximal end  127   a  includes a generally elongated configuration, and is dimensioned to move, e.g., pivot, within the shaft  12  from the open position to the closed or clamping position. Pivot pin  111  couples the first and second jaw members  110  and  120 , respectively ( FIG. 3 ) for pivotal movement relative to one another. 
     Proximal end  127   a  serves as a beam that, in concert with the links  19   a  and  19   b , regulates a clamping force at the jaw members  110  and  120  when the links  19   a  and  19   b  transition past vertical and the jaw members  110  and  120  are in the clamping position with tissue disposed therebetween. Proximal end  127   a  may be relatively resilient, or in some instances, may be substantially rigid. The resiliency, or lack thereof, may be varied based on a specific surgical procedure, manufacturer and/or user preference, etc. In the embodiment illustrated in  FIG. 3 , proximal end  127   a  is relatively resilient. 
     One or more stop members  23   b  (one stop member  23   b  is illustrated in the drawings) are operably disposed on the proximal end  127   a  of the jaw housing  127 . Stop member  23   b  is configured to contact and/or releasably engage the link  19   b  of the link assembly  19  when the links  19   a  and  19   b  have transitioned past vertical. More specifically, stop member  23   b  includes an angled trailing edge  25  that is configured to contact a leading edge  27  of the link  19   b . This contact between the angled trailing edge  25  of the stop  23   b  and the leading edge  27  of the link  19   b  facilitates “latching” jaw member  120  in the clamping position. That is, when the angled trailing edge  25  contacts the leading edge  27 , the links  19   a  and  19   b  including pivot pin  21   a  are prevented from moving distally. 
     Jaw housing  117  of jaw member  110  includes components similar to that of the components associated with jaw housing  127  of jaw member  120 . More particularly, jaw housing  117  includes proximal end  117   a  that functions similarly to that of proximal end  127   a  of jaw housing  127   a . Proximal end  117   a  of the jaw member  110  includes a stop member  23   a  having an angled trailing edge  31  that is configured to contact a corresponding leading edge  35  of the link  19   a . Stop  23   a  functions in a manner substantially similar to that of stop  23   b.    
     The jaw members  110  and  120  may be coupled to each other via any suitable coupling methods. In the illustrated embodiment, an opening  108  is defined in and extends through each jaw housing  117  and  127  and is configured to receive pivot pin  111 . Opening  108  is shown engaged with pivot pin  111  and as such is not explicitly visible. 
     In an assembled configuration, pivot pin  111  is positioned within the openings associated with each of the jaw members  110  and  120 . Once assembled, the jaw members  120  and/or jaw member  110  may be pivotably supported at the distal end  14  of the shaft  12  by known methods, such as, for example, by the method described in commonly-owned U.S. Pat. No. 7,597,693 to Garrison filed on Jun. 13, 2003. 
     In use, jaw members  110  and  120  are, initially, in the open position ( FIG. 1 ). Tissue is positioned between the jaw members  110  and  120 . Once tissue is positioned between the jaw members  110  and  120 , movable handle  40  is moved proximally ( FIG. 2 ), which, in turn, causes the drive rod  133  to move distally. Distal movement of drive rod  133  causes the links  19   a  and  19   b  to pivot, i.e., in respective clockwise and counterclockwise directions, about pivot pins  21   a - 21   c  and move distally. As links  19   a  and  19   b  move distally, the pivot pin  111  moves distally against the bias of the spring  15  and the jaw members  110  and  120  move toward one another and to the clamping position. Ultimately, links  19   a  and  19   b  transition past vertical and the respective leading edges  35  and  27  of links  19   a  and  19   b  contact respective trailing edges  31  and  25  of stops  23   a  and  23   b . Contact between the leading edges  35  and  27  and trailing edges  31  and  25  “latches” the jaw members  110  and  120  in the clamping position. Thereafter, tissue is electrosurgically treated, e.g., tissue is sealed. Subsequently, movable handle  40  is released and pivot pin  15  moves proximally and the jaw members  110  and  120  move away from one another and back to the open or neutral position. 
     The unique configuration of the link assembly  19  including links  19   a  and  19   b  and proximal ends  117   a  and  127   a  improves the opening and closing angles typically associated with known forceps jaw designs. Moreover, the unique configuration of the link assembly  19  including links  19   a  and  19   b  and proximal ends  117   a  and  127   a  eliminates the need of having the proximal ends  117   a  and  127   a  (“flags”) extend past the profile of the shaft  12 . 
     With reference to  FIG. 4 , in certain embodiments, a cam member  41  may be operably coupled to the shaft  12  and operably disposed adjacent the end effector  100 . For illustrative purposes, the stop members  23   a  and  23   b  are not shown in  FIG. 4 . The cam member  41  is configured to cam the links  19   a  and  19   b  toward a horizontal position and each other as the drive rod  133  is moved proximally. To this end, the cam member  41  includes an opening  43  that is configured to receive the drive rod  133  therethrough. Cam member  41  includes slanted leading edges  45  and  47  that are configured to contact respective trailing edges  49  and  51  of links  19   a  and  19   b  such that the jaw members  110  and  120  remain in the open or neutral position. 
     In use and with movable handle  40  in a distal position (see  FIG. 1  for example), the trailing edges  49  and  51  of links  19   a  and  19   b  contact the leading edges  45  and  47  of the cam member  41 . This contact between trailing edges  49 ,  51  and the leading edges  45 ,  47  force the links  19   a  and  19   b  to pivot about the pivot pin  21   a  and maintain the jaw members  110  and  120  in the open or neutral position. 
     From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. For example, it is contemplated that in certain instances one or more resilient members, e.g., a compression spring  200 , may be operably associated with or coupled to either the link assembly  19  including links  19   a  and  19   b  and/or one or both of the jaw members  110  and  120  (see  FIG. 5 , for example). More particularly, a compression spring  200  may be coupled to the pivot pin  21   a  and the pivot pin  111  by one or more suitable coupling methods, e.g., soldering. In this instance, the spring  200  may be configured to provide a clamping force or seal force in the range of about 3 kg/cm 2  to about 16 kg/cm 2  between the jaw members  110  and  120  when the jaw members  110  and  120  are in the clamping position. 
     With reference to  FIG. 5 , an end effector assembly  300  is illustrated. End effector assembly  300  is substantially similar to end effector  100 . As a result thereof, only those features unique to end effector  300  are described herein. In the embodiment illustrated in  FIG. 5 , the cam member  41  is configured to translate along the longitudinal axis “A-A” (see  FIG. 5 ). More particularly, cam member  41  is movable from a proximal position that corresponds to the jaw members  110  and  120  being in the clamping position to a distal position that corresponds to the jaw members being in the open position. 
     Unlike the previously described embodiments, the cam member  41  operably couples (via one or more suitable coupling methods, e.g., soldering) to a bifurcated distal end  135  having bifurcated ends  135   a  and  135   b  and the link assembly  19  is fixedly attached to an internal frame of the shaft  12 . Operation of the forceps  10  with the end effector  200  is substantially similar to that of end effector  100 . A distinguishing feature of the operation of the forceps  10  with the end effector  300  when compared to the end effector  100 , is that the jaw members  100  and  200  are biased in the clamping configuration by the spring  200  that provides a clamping force or seal force in the range of about 3 kg/cm 2  to about 16 kg/cm 2  between the jaw members  110  and  120 . Moreover, when movable handle  40  is moved proximally, cam member  41  moves distally and contacts the links  19   a  and  19   b , which, in turn, causes the links  19   a  and  19   b  to pivot about the pivot pin  21   a  and the jaw members  110  and  120  to move away from each other to the open position against the bias of the spring  200 . 
     With reference to  FIG. 6 , an end effector assembly  400  is illustrated. End effector assembly  400  is substantially similar to end effectors  100  and  300 . As a result thereof, only those features unique to end effector  400  are described herein. In the embodiment illustrated in  FIG. 6 , a cam member  410  includes two generally arcuate slots  46   a  and  46   b  that respectively couple to pivot pins  21   c  and  21   b  of the links  19   a  and  19   b  (see  FIG. 6 ). Operation of the forceps  10  with the end effector  400  is substantially similar to that of end effector  300 . However, unlike cam member  41 , distal movement of the cam member  410  causes the pivot pins  21   c  and  21   b  to translate distally within the arcuate cam slots  46   a  and  46   b , respectively, which, in turn, causes the jaw members  110  and  120  to move away from each other to the open position against the bias of the spring  200 . 
     With reference to  FIG. 7 , an end effector assembly  500  is illustrated. End effector assembly  500  is substantially similar to end effectors  100  and  300 . As a result thereof, only those features unique to end effector  500  are described herein. 
     The distal end  135  of the driving structure  133  is bifurcated or split with two legs or branches  135   a  and  135   b  that couple to respective resilient members  200   a  and  200   b.    
     Resilient members  200   a  and  200   b  may be any suitable type of resilient member including but not limited to: springs selected from the group consisting of coil, leaf and tension; gas or fluid pistons; and elastomers or other compliant materials. 
     A proximal end of the resilient member  200   a  operably couples to the branch  135   a  of the driving structure  133  by any of the aforementioned coupling methods (e.g., soldering, welding, or solid joints) and a distal end of the resilient member  200   a  operably couples (e.g., also by soldering) to a movable cam member  510  (cam member  510 ). Likewise, a proximal end of the resilient member  200   b  operably couples, e.g., via soldering, to the branch  135   b  of the driving structure  133  and a distal end of the resilient member  200   b  operably couples (e.g., also by soldering) to the pivot pin  21   a  of the link assembly  19 . To facilitate moving cam member  510 , the resilient members  200   a  and  200   b  are disposed in different horizontal planes from each other. More particularly, resilient member  200   a  is located above the resilient member  200   b.    
     Unlike cam member  410 , a cam member  510  includes two slanted or angled cam slots  510   a  and  510   b  that are configured to house respective stationary cam pins  511   a  and  511   b  that are operably coupled to the jaw members  120  and  110 , respectively. Cam member  510  is movable along the longitudinal axis “A-A.” In certain embodiments, the cam slots  510   a  and  510   b  may be in the jaw members  110  and  120  and the cam pins  511   a  and  511   b  may be attached to the cam member  510 . 
     In use, proximal movement of the movable handle  40  causes the driving structure  133  including the bifurcated distal end  135  to move distally, thus, moving the cam member  510  including the cam slots  510   a  and  510   b  distally, which, in turn, cams the cam pins  511   a  and  511   b  causing the jaw members  110  and  120  to move toward each other to the clamping position ( FIG. 7 ). Distal motion of movable handle  40  causes the driving structure  133  including the bifurcated distal end  135  to move proximally, thus, moving the cam member  510  including the cam slots  510   a  and  510   b  proximally, which, in turn, cams the cam pins  511   a  and  511   b  causing the jaw members  110  and  120  to move away from each other to the open position. 
     With reference to  FIG. 8 , an end effector assembly  600  is illustrated. End effector assembly  600  is substantially similar to end effector  500 . As a result thereof, only those features unique to end effector  600  are described herein. 
     Unlike the previously described jaw members, the jaw members  110  and  120  illustrated in  FIG. 8  include respective proximal ends  117   a  and  127   a  that are “offset” from the respective distal ends  117   b  and  127   b.    
     In the embodiment illustrated in  FIG. 8 , the cam pin  21   b  operably couples the link  19   b , the cam slot  510   a  and the proximal end  117   a  of the jaw member  110  to each other. Likewise, the cam pin  21   c  operably couples the link  19   a , the cam slot  510   b  and the proximal end  127   a  of the jaw member  120  to each other. 
     In use, proximal movement of the movable handle  40  causes the driving structure  133  including the bifurcated distal end  135  to move distally, thus, moving the cam member  510  including the cam slots  510   a  and  510   b  distally, which, in turn, cams the cam pins  511   a  and  511   b  causing the jaw members  110  and  120  to move away from each other to the open position ( FIG. 8 ). Distal motion of movable handle  40  causes the driving structure  133  including the bifurcated distal end  135  to move proximally, thus, moving the cam member  510  including the cam slots  510   a  and  510   b  proximally, which, in turn, cams the cam pins  511   a  and  511   b  causing the jaw members  110  and  120  to toward each other to the closed position. 
     With reference to  FIG. 9 , an end effector assembly  700  is illustrated. End effector assembly  700  is substantially similar to end effector  600 . As a result thereof, only those features unique to end effector  700  are described herein. 
     In the embodiment illustrated in  FIG. 9 , the cam pin  21   b  operably couples the link  19   b , the cam slot  510   a  and the proximal end  127   a  of the jaw member  120  to each other. Likewise, the cam pin  21   c  operably couples the link  19   a , the cam slot  510   b  and the proximal end  117   a  of the jaw member  110  to each other. 
     The driving structure  133  does not include a bifurcated distal end  135 . Accordingly, unlike the resilient member  200   a  that includes a proximal end that operably couples to the branch  135   a  of the driving structure  133 , a proximal end of the resilient member  200   a ′ is operably coupled to the pivot pin  21   a  ( FIG. 9 ). Moreover, the spring  200   a ′ is disposed in the same horizontal plane as the spring  200   b.    
     In use, proximal movement of the movable handle  40  causes the driving structure  133  to move distally, thus, moving the cam member  510  including the cam slots  510   a  and  510   b  distally, which, in turn, cams the pivot pins  21   b  and  21   c  causing the jaw members  110  and  120  to move toward each other to the clamping position ( FIG. 9 ). Distal motion of movable handle  40  causes the driving structure  133  to move proximally, thus, moving the cam member  510  including the cam slots  510   a  and  510   b  proximally, which, in turn, cams the pivot pins  21   b  and  21   c  causing the jaw members  110  and  120  to move away from each other to the open position. 
     With reference to  FIG. 10 , an end effector assembly  800  is illustrated. End effector assembly  800  is substantially similar to end effector  700 . As a result thereof, only those features unique to end effector  800  are described herein. 
     A support structure  801  of suitable proportion is operably disposed adjacent the end effector  800 . Support structure  801  is configured to couple to one or more resilient members  200   a″.    
     In the embodiment illustrated in  FIG. 10  two resilient members  200   a ″ are illustrated. Each resilient member  200   a ″ includes proximal ends that couple to a distal end of the cam member  510  and distal ends that operably couple to the support structure  801 . 
     A third resilient member  200   b ′ includes a proximal end that operably couples to the pivot pin  21   a  and a distal end that operably couples to the support structure  801 . 
     In use, proximal movement of the movable handle  40  causes the driving structure  133  to move distally, thus, moving the cam member  510  including the cam slots  510   a  and  510   b  distally, which, in turn, cams the pivot pins  21   b  and  21   c  causing the jaw members  110  and  120  to move toward each other to the clamping position ( FIG. 10 ). Distal motion of movable handle  40  causes the driving structure  133  to move proximally, thus, moving the cam member  510  including the cam slots  510   a  and  510   b  proximally, which, in turn, cams the pivot pins  21   b  and  21   c  causing the jaw members  110  and  120  to move away from each other to the open position. 
     With reference to  FIG. 11 , an end effector assembly  900  is illustrated. End effector assembly  900  is substantially similar to end effectors  500  and  600 . As a result thereof, only those features unique to end effector  900  are described herein. 
     A resilient member  200   c  includes a distal end that operably couples to a cam pin  21   d  that is operably coupled to a pair of cam slots  127   c  and  117   c  that are disposed on respective jaw members  120  and  110  at proximal ends  127   a  and  117   a  thereof. 
     In use, proximal movement of the movable handle  40  causes the driving structure  133  including bifurcated distal end  135  to move proximally, thus, moving the cam pin  21   d  proximally within the cam slots  127   c  and  117   c , which, in turn, causes the jaw members  110  and  120  to move toward each other to the clamping position ( FIG. 11 ). Distal motion of movable handle  40  causes the driving structure  133  including the bifurcated distal end  135  to move distally, thus, moving the cam pin  21   d  distally within the including the cam slots  127   c  and  117   c , which, in turn, causes the jaw members  110  and  120  to move away from each other to the open position. 
     While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.