Patent Publication Number: US-2021177499-A1

Title: Apparatus for performing an electrosurgical procedure

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/556,619, filed on Aug. 30, 2019, which is a continuation of U.S. patent application Ser. No. 15/338,510, filed Oct. 31,  2016 , now U.S. Pat. No. 10,426,544, which is a divisional application of U.S. patent application Ser. No. 14/083,696, filed Nov. 19, 2013, now U.S. Pat. No. 9,480,522, which is a divisional application of U.S. patent application Ser. No. 12/792,038, filed on Jun. 2, 2010, now U.S. Pat. No. 8,585,736. 
    
    
     INTRODUCTION 
     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 providing a mechanical advantage at the end effector. 
     BACKGROUND 
     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 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 rod, 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. 
     In certain instances, 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 types of springs, e.g., a compression spring, may operably couple to the handle assembly associated with the electrosurgical forceps. In this instance, the spring is typically operatively associated with the drive assembly to facilitate actuation of a movable handle associated with the handle assembly to ensure that a specific closure force between the jaw members is maintained within one or more suitable working ranges. 
     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) the frictional losses associated with drive rod translating through the shaft are transferred to the spring in the housing, 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. 
     An increased mechanical advantage and/or mechanical efficiency with respect to transferring the closure force(s) from the handle assembly to the jaw members may prove advantageous in the relevant art. 
     SUMMARY 
     The present disclosure provides an endoscopic forceps. The endoscopic forceps includes a housing having a shaft that extends therefrom defining a longitudinal axis therethrough. An end effector assembly is operatively connected to a distal end of the shaft and has a pair of first and second jaw members. The first and second jaw members 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 assembly is operably coupled to a handle assembly associated with the housing. The drive assembly includes a wire having a proximal end and a distal end. The distal end has a split wire configuration including two ends that operably couple to a respective first and second jaw member. The two ends configured to impart movement of a respective jaw member when the handle assembly is actuated. One or both of the two ends forms a spring component that is operably associated with one or both of the first and second jaw members and is configured to bias the jaw members in the open position. 
     The present disclosure provides an endoscopic forceps that includes a housing having a shaft that extend therefrom and define a longitudinal axis therethrough. An end effector assembly is operatively connected to a distal end of the shaft and has a pair of first and second jaw members that are movable relative to one another. A drive assembly is operably coupled to a handle assembly associated with the housing. The drive assembly includes two wires each including a proximal end that operably couples to the handle assembly and a distal end that operably couples to a respective first and second jaw member. The two wires configured to impart movement of a respective jaw member when the handle assembly is actuated. A center link operably coupled to the first and second jaw members via a respective cam member that is operably disposed within a respective cam slot associated with a respective jaw member. 
     The present disclosure provides an endoscopic forceps that includes a housing having a shaft that extends therefrom that defines a longitudinal axis therethrough. An end effector assembly is operatively connected to a distal end of the shaft and has a pair of first and second jaw members. The first and second jaw members 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 is operably coupled to a handle assembly associated with the housing and operably coupled to a biasing component operably associated with the first and second jaw members. The biasing component is movable in a plane that is orthogonal to the longitudinal axis and configured to impart movement of the first and second jaw members when the handle assembly is actuated. 
     The present disclosure also provides an endoscopic forceps that includes a housing having a shaft that extends therefrom that defines a longitudinal axis therethrough. An end effector assembly is operatively connected to a distal end of the shaft and has a pair of first and second jaw members. The first and second jaw members operably disposed in an open position wherein the first and second jaw members are in spaced relation relative to one another. Each of the first and second jaw members including a respective seal plate that is movable from an initial position for positioning tissue therebetween to a subsequent position wherein the respective seal plates cooperate to grasp tissue therebetween. A drive mechanism is operably coupled to a handle assembly associated with the housing and operably coupled to biasing components operably associated with each of the respective seal plates. The biasing components configured to impart movement of the respective seal plates when the handle assembly is actuated. The biasing components operably coupled to the respective seal plates are in the form of respective bellows that are heat activated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       Various embodiments of the present disclosure are described hereinbelow with references to the drawings, wherein: 
         FIG. 1A  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. 1B  is a side, perspective view of the endoscopic bipolar forceps depicted in  FIG. 1A  illustrating internal components associated with a handle assembly associated with the endoscopic bipolar forceps; 
         FIGS. 2A and 2B  are schematic views of jaw members that may be utilized with the forceps  FIGS. 1A and 1B ; 
         FIGS. 3A and 3B  are schematic views of jaw members configured for use with the endoscopic forceps depicted in  FIGS. 1A and 1B  according to an alternate embodiment of the present disclosure; 
         FIG. 4  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. 5A  is a schematic, side view of a hydraulic drive mechanism associated with the endoscopic bipolar forceps depicted in  FIG. 4 ; 
         FIG. 5B  is a schematic, top elevational view of the hydraulic drive mechanism depicted in  FIG. 5A ; 
         FIGS. 6A and 6B  are schematic views of jaw members configured for use with the endoscopic forceps depicted in  FIG. 4  according to another embodiment of the present disclosure; 
         FIGS. 7A and 7B  are schematic views of jaw members configured for use with the endoscopic forceps depicted in  FIG. 4  according to yet another embodiment of the present disclosure; and 
         FIGS. 8A and 8B  are schematic views of jaw members configured for use with the endoscopic forceps depicted in  FIG. 4  according to still 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. 
     With reference to  FIGS. 1A and 1B , an illustrative embodiment of an electrosurgical apparatus, e.g., a bipolar forceps  10  is shown. Bipolar 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 generator may be configured for monopolar and/or bipolar modes of operation. The generator may form part of a system (not shown) that may include one or more processors in operative communication with one or more control modules that are executable on the processor. The control module (not explicitly shown) 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 one or both seal plates  118 ,  128 . 
     Bipolar forceps  10  is shown configured for use with various electrosurgical procedures and generally includes a housing  20 , electrosurgical cable  310  that connects the forceps  10  to a source of electrosurgical energy (e.g., electrosurgical generator not shown), a handle assembly  30 , a rotating assembly  80 , a trigger assembly  70 , a drive assembly  130  (see  FIG. 1B ), and an end effector assembly  100  that operatively connects to the drive assembly  130 . The drive assembly  130  may be in operative communication with handle assembly  30  for imparting movement of one or both of a pair of jaw members  110 ,  120  of end effector assembly  100 . Conventional drive assemblies typically utilize one or more types of springs, e.g., a compression spring, to facilitate closing the jaw members  110  and  120 . For illustrative purposes, a compression spring  131  (see  FIG. 1B ) is shown separated from the housing  20 . End effector assembly  100  includes opposing jaw members  110  and  120  ( FIGS. 1A and 1B ) that mutually cooperate to grasp, seal and, in some cases, divide large tubular vessels and large vascular tissues. 
     With continued reference to  FIGS. 1A and 1B , forceps  10  includes a shaft  12  that has a distal end  14  configured to mechanically engage the end effector assembly  100  and a proximal end  16  that mechanically engages the housing  20 . In the drawings and in the descriptions that follow, the term “proximal,” as is traditional, will refer to the end of the forceps  10  which is closer to the user, while the term “distal” will refer to the end that is farther from the user. 
     Handle assembly  30  includes a fixed handle  50  and a movable handle  40 . Fixed handle  50  is integrally associated with housing  20  and handle  40  is movable relative to fixed handle  50 . Movable handle  40  of handle assembly  30  is ultimately connected to the drive assembly  130 , which together mechanically cooperate to impart movement of one or both of the jaw members  110  and  120  to move from an open position, wherein the jaw members  110  and  120  are disposed in spaced relation relative to one another, to a clamping or closed position, wherein the jaw members  110  and  120  cooperate to grasp tissue therebetween. 
     For a more detailed description of the bipolar forceps  10  including handle assembly  30  including movable handle  40 , rotating assembly  80 , trigger assembly  70 , drive assembly  130 , and electrosurgical cable  310  (including line-feed configurations and/or connections), reference is made to commonly owned U.S. Patent Publication No. 2007/0173814 filed on Nov. 9, 2006. 
     With reference now to  FIGS. 2A and 2B , a drive mechanism  150  is operably associated with the drive assembly  130 . Drive mechanism  150  may be any suitable drive mechanism including but not limited to a flexible or resilient band, a cable, a wire, etc. In the illustrated embodiment, where the drive mechanism  150  is operatively associated with an endoscopic instrument, the drive mechanism  150  is substantially flexible to accommodate bends typically associated with shaft  12  when the bipolar forceps  10  is remotely actuatable relative to a patient. To this end, the drive mechanism  150  includes a wire  151  of suitable proportion that allows the wire  151  ( FIG. 2A ) to “bend” or “flex” when the wire  151  is translated, e.g., “pulled” or “pushed.” within the shaft  12 . 
     Wire  151  includes a proximal end (not explicitly shown) and a distal end  152 . The proximal end operably couples to the drive assembly  130  such that actuation of the movable handle  40  imparts movement of the jaw members  110  and  120 . In the embodiment illustrated in  FIGS. 2A and 2B , distal end  152  of the wire  151  splits or divides forming a split wire configuration having two generally resilient ends  151   a  and  151   b  that operably couple to a respective jaw member  110  and  120 , described in greater detail below. The resilient ends  151   a  and  151   b  of the split wire configuration bias the jaw members  110  and  120  in an opened configuration and are configured to facilitate movement of the jaw members  110  and  120  when the movable handle  40  is actuated, e.g., moved proximally. More particularly, resilient ends  151   a  and  151   b  form a resilient or “spring-like component”  153  (hereinafter simply referred to as spring  153 ) that is operably associated with each of the jaw members  110  and  120  and configured to bias the jaw members  110  and  120  in the opened position for positioning tissue between the jaw members  110  and  120 . Moreover, the resilient ends  151   a  and  151   b  are configured to collectively provide the necessary closure or sealing force at the jaw members  110  and  120  when the jaw members  110  and  120  are in the clamping position. More particularly, in the illustrated embodiment, the combination of resilient ends  151   a  and  151   b  is configured to provide a spring  153  that is capable of providing a closure force at the jaw members  110  and  120  that is in the range of about 3 kg/cm 2  to about 16 kg/cm 2  or about 120 pounds per square inch; other suitable ranges are contemplated. 
     Wire  151  including resilient ends  151   a  and  151   b  are configured such that when the movable handle  40  is moved a predetermined distance, the resilient ends  151   a  and  151   b  are caused to toward each other, which, in turn, causes the jaw members  110  and  120  to move a corresponding predetermined distance toward each other (or multiple thereof by virtue of one or more known mechanical multipliers, e.g., gear, pulleys solenoids, etc.) to an closed position. To this end, each of the resilient ends  151   a  and  151   b  includes a radius of curvature “R” of suitable dimensions to accomplish a particular surgical purpose. Resilient ends  151   a  and  151   b  may also operably cooperate with one more additional springs disposed in the housing  20  to provide the necessary closure forces, e.g., the resilient ends  151   a  and  151   b  are configured to offload some of the required forces from a more transitional spring disposed in the housing  20 . 
     With continued reference to  FIGS. 2A and 2B , jaw members  110 ,  120  are shown. 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, and so forth. In the embodiment illustrated in  FIGS. 2A and 2B , each of the jaw members  110  and  120  including respective housings  117  and  127  is formed from metal. Jaw members  110  and  120  are operatively and pivotably coupled to each other via a pivot pin  111  (or other suitable device). Respective electrically conductive seal plates  118  and  128  are operably supported on and secured to jaw housings  117  and  127  of respective the jaw members  110  and  120 . More particularly, a distal end  117   a  and a distal end  127   a  of respective jaw members  110  and  120  may be configured to securely engage the respective electrically conductive seal plate  118  and  128  or, with respect to a monolithic jaw member, form the seal plates  118  and  128 . 
     It should be noted that jaw members  110  and  120  and respective housings  117  and  127  are substantially identical to each other. In view thereof, and so as not to obscure the present disclosure with redundant information, the operative components associated with the jaw member  110  and jaw housing  117  that are operably associated with the drive mechanism  150  including wire  151  are described in further detail, and only those features distinct to jaw member  120  and jaw housing  127  will be described hereinafter. 
     Continuing with reference to  FIGS. 2A and 2B , proximal end  117   b  of jaw housing  117  is disposed in an oblique orientation with respect to an axis “B-B” that is defined through the end effector  100 . More particularly, axis “B-B” is substantially parallel to the longitudinal axis “A-A” that is defined through the shaft  12 . Proximal end  117   b  may be disposed at any suitable angle, e.g., 0-90°, with respect to the axis “B-B.” In the illustrated embodiment, proximal end  117   b  is oriented at approximately a 45° angle with respect to the axis “B-B.” Disposing the proximal end  117   b  in an oblique orientation with respect to the axis “B-B” facilitates opening and closing the jaw members  110  and  120 . Moreover, the angle may be adjusted to accommodate and/or achieve specific closure or sealing forces at the jaw member  110  and  120  when the jaw members are in the closed or clamping position, e.g., the greater the angle of the proximal end  117   b  with respect to the axis “B-B,” the greater the closure force (for a given configuration of the distal end  152 ) when the jaw members  110  and  120  are in the clamping position. 
     In accordance with the present disclosure, jaw housings  117  and  127  include respective proximal ends  117   b  and  127   b  that operably couple to respective resilient ends  151   a  and distal end  151   b  of the split wire configuration to facilitate opening and closing in of the jaw members  110  and  120 . More specifically, proximal end  117   b  is in operative communication with resilient end  151   a  of wire  151  such that proximal movement of the wire  151  causes one or both of the jaw members  110  and  120  to move from the open position ( FIG. 1A ) to the closed or clamping position ( FIG. 1B ). For example, in one particular embodiment, when the wire  151  is “pulled,” i.e., moved or translated proximally, resilient end  151   a  and resilient end  151   b  are caused to move toward one another, which, in turn, causes both of the jaw members  110  and  120  to move toward one another. Alternatively, and if desired, the drive assembly  130  including the wire  151  and resilient ends  151   a  and  151   b  may be configured such that when the wire  151  is “pushed,” i.e., moved or translated distally, both of the jaw members  110  and  120  are caused to move toward one another. 
     Proximal end  117   b  operably and securely couples to resilient end  151   a  of the wire  151  by any suitable method. In the illustrated embodiment, proximal end  117   b  includes an aperture  115  defined therein of suitable proportion that is dimensioned to operably couple to a distal tip  155  of the resilient end  151   a.  The distal tip  155  may be shaped to engage aperture  115 . In the illustrated embodiment, the distal tip  155  is “hook” shaped to facilitate securement of the distal tip  155  within the aperture  115 . In one particular embodiment, a bead of solder may be placed about aperture  115  of the proximal end  117   b  to ensure that the proximal end  117   b  and distal end  151   a  remain secured to each other during opening and closing sequences. 
     An opening  108  extends through a medial portion of the jaw housing  117   b  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 the embodiment, illustrated in  FIGS. 2A and 2B , opening  108  (and the pivot pin  111  housed therein) includes a generally circumferential configuration. In certain embodiments, pivot pin  111  is securely disposed to an internal frame associate with the shaft  12  and/or the end effector  100 . 
     In an assembled configuration each of the jaw members  110  and  120  is positioned in side-by-side relation. Pivot pin  111  is positioned within the opening  108  associated with jaw member  110  and a corresponding opening (not explicitly shown) associated with jaw member  120 . As noted above, the pivot pin  111  provides a point of pivot for each of the jaw members  110  and  120 . The jaw members  110  and  120  may be pivotably supported at the distal end  14  of the shaft  12  by any suitable method, such as, for example, by the method described in commonly-owned U.S. Patent Application publication No. 2007/0260242, filed Jul. 11, 2007. 
     In use, initially jaw members  110  and  120  are biased in an open position under the force provided by the spring  153  formed by the resilient ends  151   a  and  151   b  ( FIGS. 1A and 2A ). Tissue is positioned between the jaw members  110  and  120 . Proximal movement of the movable handle  40  “pulls” wire  151  proximally, which, in turn, causes the resilient ends  151   a  and  151   b  to move toward each other, this, in turn, causes the jaw members  110  and  120  to toward each other against the bias of spring  153  such that tissue is clamped between the jaw members  110  and  120  ( FIGS. 1B and 2B ). The configuration of the spring  153  (e.g., the radius of curvature “R” associated with each of the resilient ends  151   a  and  151   b ) generates a sealing or closure force at the jaw members  110  and  120 . The combination of jaw members  110  and  120  including jaw housings  117  and  127  operably coupled to the wire  151  including resilient ends  151   a  and  151   b  provides a consistent, uniform tissue effect, e.g., tissue seal. Moreover, the frictional losses that are typically associated with conventional forceps when a drive rod is translated within a shaft are offloaded and/or diminished by the spring-like component  153  operably associated with the jaw members  110  and  120 . In other words, it is irrelevant if the shaft  12  is bent or articulated since the biasing force of the resilient spring ends  151   a  and  151  located at the jaw members  110  and  120  will remain unaffected. 
     With reference to  FIGS. 3A and 3B , an alternate embodiment of end effector  100  that is suitable for use with the bipolar forceps  10  depicted in  FIGS. 1A and 1B  is shown and end effector designated  200 . End effector  200  includes two jaw members  210  and  220  that are similar to that of jaw members  110  and  120 , respectively. Accordingly, only those features that are unique to jaw members  210  and  220  are discussed in further detail. 
     Each of jaw members  210  and  220  includes a respective cam slot  222  and  224  defined therein disposed on a respective proximal end  217   b  and  227   b  ( FIGS. 3A and 3B ) thereof. Each of the cam slots  222  and  224  is configured to operably couple to a center link  260  that is operably associated with each of the jaw members  210  and  220 , described in greater detail below. Each of the cam slots  222  and  224  is disposed in a generally parallel configuration with respect to a longitudinal axis “C-C” that is parallel to the longitudinal axis “A-A.” 
     As described above with respect to jaw members  110  and  120 , jaw members  210  and  220  are pivotably coupled to each other via pivot pin  111 . 
     A distinguishing feature of the jaw members  210  and  220  when compared to jaw members  110  and  120  is the generally “U” shaped medial portion  211  and  221  associated with each of the jaw members  210  and  220 , respectively. The medial portions  211  and  221  provide a structural transition from a respective distal end  217   a  and  227   a  to the respective proximal end  217   b  and  227   b  of the jaw members  210  and  220  such that the respective proximal and distal ends  217   a,    227   a  and  217   b  and  227   b  remain in substantial parallel alignment with respect to each other when the jaw members  210  and  220  are moved from the open to clamping position (see  FIG. 3A  in combination with  3 B). The parallel alignment of the respective proximal and distal ends and center link  260  provides increased structural integrity to the jaw housings  217  and/or the jaw member  210  and facilitates the transfer of closure force to the jaw members  210  and  220  when the jaw members  210  and  220  are in the clamping position. 
     A drive mechanism  250  operably couples to the drive assembly  130  and is in operative communication with the end effector  200 . Drive mechanism  250  is configured similar to that of drive mechanism  150 . More particularly, drive mechanism  250  is operably associated with the drive assembly  130  and may be any suitable drive mechanism including but not limited to one or more flexible or resilient bands, cables, wires, etc. Similar to that of drive mechanism  150 , the drive mechanism  250  is substantially flexible to accommodate bends typically associated with shaft  12  when the bipolar forceps  10  is positioned within a patient and when the jaw members  210  and  220  are being moved from an open configuration for positioning tissue between the jaw members, to a closed configuration for grasping tissue. With this purpose in mind, the drive mechanism  250  includes a split wire configuration having a pair of wires  251  and  252  disposed in substantial parallel relation with respect to each other and proportioned such that the wires  251  and  252  “bend” or “flex” when the wires  251  and  252  are pulled and/or pushed within the shaft  12 . 
     Each of the wires  251  and  252  includes a proximal end (not explicitly shown) that is operably associated with the drive assembly  130  such that actuation of the movable handle  40  imparts movement of the jaw members  210  and  220 . 
     Each of the wires  251  and  252  operably couples to a respective jaw member  210  and  220 . More particularly, each of the wires includes a respective distal end  251   a  and  252   a  that operably couples to center link  260  which, in turn, operably couples to each of the jaw members  210  and  220 , described in greater detail below. 
     In the embodiment illustrated in  FIGS. 3A and 3B , the wires  251  and  252  are configured such that movement of one wire, e.g., wire  251 , in a first direction, e.g., a proximal direction, causes movement of the other wire, e.g., wire  252 , in a second direction, e.g., a distal direction, see  FIGS. 3A and 3B , for example. Accordingly, when the movable handle  40  is moved, e.g., moved proximally, the wires  251  and  252  cause the jaw members  210  and  220  to move from the open position to the closed position (see  FIGS. 3A and 3B ). 
     Center link  260  operably couples to each of the jaw members  210  and  220  and is configured to move the jaw members  210  and  220  from the open configuration to the closed configuration when the movable handle  40  is move proximally. More particularly, center link  260  operably couples to cam slot  222  disposed on jaw member  210  and cam slot  224  disposed on jaw member  220  (see  FIGS. 3A and 3B ) via one or more coupling methods. More particularly, center link  260  includes a cam pin  262  that is operably disposed within the cam slot  222  and a cam pin  264  that is operably disposed within the cam slot  224 . This cam pin and cam slot configuration facilitates proximal and distal movement or translation of the center link  260  when the movable handle  40  is moved proximally. Center link  260  is configured such that center link  260  is operably disposed in a generally oblique orientation with respect to the longitudinal axis “C-C” when the jaw members  210  and  220  are in the open position ( FIG. 3A ) and is disposed in a generally orthogonal orientation with respect to the longitudinal axis “C-C” when the jaw members  210  and  220  are in the closed position ( FIG. 3B ). 
     To facilitate movement of center link  260 , an aperture (not explicitly shown) of suitable proportion is operably defined in center link  260  and is configured to securely engage a pivot pin  265  that is secured to an internal portion of the shaft  12  and/or end effector  200 . 
     A resilient or “spring-like component”  253  (hereinafter simply referred to as spring  253 ) is operably associated with each of the jaw members  210  and  220  and is configured to bias the jaw members  210  and  220  in the open position such that tissue may be positioned between the jaw members  210  and  220 . Moreover, the spring  253  and center link  260  collectively provide a closure force at the jaw members  110  and  120  that is in the range of about 3 kg/cm 2  to about 16 kg/cm 2  or about 120 pounds per square inch when the jaw members  210  and  220  are in the clamping position. Spring  253  is operably secured or coupled to a respective proximal end  217   b  and  227   b  of each of the jaw members  210  and  220  by any suitable securement or coupling methods. In the illustrated embodiment, the spring  253  is overmolded to each of the proximal ends  217   b  and  227   b  of the jaw members  210  and  220 , respectively. Alternatively, spring  253  may be secured to the proximal ends  217   b  and  227   b  by one or more mechanical connections, e.g., rivet or pin. Spring  253  may be any suitable type of spring including but not limited to compression spring, torsion spring, leaf spring, etc. In the embodiment illustrated in  FIGS. 3A and 3B , the spring  253  is a compression spring  253 . 
     While the spring  253  has been described herein as being operably associated with the center link  260  to bias the jaw members  210  and  220  in the open position, it is within the purview of the present disclosure that the center link  260  function without the spring  253 . 
     Operation of the bipolar forceps  10  with the end effector  200  is described. In use, initially jaw members  210  and  220  are biased in an opened position under the force provided by the spring  253  ( FIG. 3A ). Tissue is positioned between the jaw members  210  and  220 , the movable handle  40  is moved proximally causing the wire  251  to move proximally and wire  252  to move distally. This proximal and distal movement of the wires  251  and  252 , respectively, causes cam pins  262  and  264  of the center link  260  to translate in a corresponding direction within respective cam slots  222  and  224  against the bias of the spring  253 , which, in turn, causes both of the jaw members  210  and  220  to move toward each other such that tissue is grasped between the jaw members  210  and  220  ( FIG. 3B ). The jaw housings  217  and  227  with center link  260  and spring  253  generate a sealing or closure force at the jaw members  210  and  220 . This combination of jaw housings  217  and  227  with center link  260  and spring  253  provides a consistent, uniform tissue effect, e.g., tissue seal. Moreover, the combination of jaw housings  217  and  227  with center link  260  and spring  253  provides an additional mechanical advantage at the jaws  110  and  120 . More particularly, the frictional losses that are typically associated with conventional forceps when a drive rod is translated within a shaft is offloaded and/or diminished by the spring  253  operably associated with the jaw housing  217  and  127 . 
     With reference to  FIG. 4 , an alternate embodiment of the bipolar forceps  10  is shown designated  10   a.  Bipolar forceps  10   a  is similar to bipolar forceps  10 . A distinguishing feature of bipolar forceps  10   a  when compared to bipolar forceps  10  is that a drive assembly  330  is disposed in operative communication with an end effector  300  via a hydraulic drive mechanism  350  (as best seen in  FIGS. 5A and 5B ), a pneumatic drive mechanism  360  and/or an electromechanical drive mechanism  370 . In the embodiment illustrated in  FIG. 4 , drive assembly  330  may operably couple to the movable handle  40  via one or more suitable coupling methods. For example, in the illustrative embodiment, the movable handle  40  may operably couple to one (or combination thereof) of the aforementioned drive mechanisms, e.g., the hydraulic drive assembly  350 , via one or more pivot pins. More particularly, a pivot pin  380   a  operably couples the movable handle  40  to an internal frame of the housing  20 , a pivot pin  380   b  operably couples the movable handle  40  to the hydraulic drive mechanism  350  and a pivot pin  380   c  operably couples the hydraulic drive mechanism  350  to the internal frame of the housing  20 , shown in phantom in  FIG. 4 . Drive assembly  330  is configured such that proximal movement of the movable handle  40  causes the drive assembly  330  (or operative component associated therewith) to engage and actuate one of the foregoing drive mechanisms (e.g., the hydraulic drive mechanism  350 ) that includes a biasing component such that jaw members  310  and  320  associated with the end effector  300  move from an open position to a closed position, described in greater detail below. 
     With reference now to  FIGS. 5A and 5B , and initially with reference to  FIG. 5A , hydraulic drive mechanism  350  (HDR  350 ), and operative components associated therewith, is illustrated. HDR  350  includes a main housing  352  that is operably disposed within the housing  20  of the bipolar forceps  10   a  and is in operative communication with the drive assembly  330  and fluid communication with end effector  300  including jaw members  310  and  320  via a hydraulic fluid line  354 . 
     With continued reference to  FIG. 5A , main housing  352  operably connects to an adjustment device  356 . In the embodiment illustrated in  FIG. 5A , the adjustment device  356  is supported by the main housing  352  and is configured to adjust a throw of the jaw members  310  and  320 . That is, the adjustment device  356  is configured to control, inter alia, the amount of deflection or movement of the jaw members  310  and  320 . To this end, a thumb screw  358  (or other suitable device) operably couples to the adjustment device  356 . More particularly, thumbscrew  358  is operably disposed on an exterior of the housing  20  (shown for illustrative purposes in  FIG. 5A ) and is accessible to a user. In use, a user may rotate, e.g., either in a clockwise or counterclockwise direction, the thumbscrew  358  to achieve a specific amount of deflection or movement at the jaw members  310  and  320 . 
     As noted above, drive assembly  330  engages the HDR  350 . More particularly, a proximal end of the HDR  350  is dimensioned to movably retain a plunger  362  that is operably coupled to the drive assembly  330 . Plunger  362  translates within the main housing  352  such that displacement of the plunger  362  within the main housing  352  causes a corresponding movement of the jaw members  310  and  320 . The plunger  362  includes a plunger head  363  dimensioned to provide a fluid tight seal between the main housing  352  and the plunger head  363 . This fluid tight seal maintains the pressure within the hydraulic fluid line  354  such that an optimum amount of deflection or movement is achieved for a given end effector. 
     A spring  364  is operably secured within the main housing  352  and is configured to control seal or closure pressure at the jaw members  310  and  320  when the jaw members are in the clamping position. 
     Hydraulic fluid line  354  couples to a distal end of the main housing  352  and is proportioned and dimensioned to couple to the end effector  300  including jaw members  310  and  320 . Hydraulic line  354  may be made from any suitable material, e.g., a substantially flexible material, and extends within the shaft  12 , shown in phantom in  FIG. 4 . Hydraulic fluid line  354  holds one or more suitable hydraulic fluids therein, e.g., saline, that provides the requisite pressure for closing and opening the jaw members  310  and  320 . More particularly, as the movable handle  40  is moved proximally, the plunger  362  including plunger head  363  causes the hydraulic fluid to move within the hydraulic fluid line  354  such that the jaw members  310  and  320  move from the open position to the clamping position. 
     In one particular embodiment, a reservoir  368  is in fluid communication with the main housing  352  and is configured to automatically supply hydraulic fluid into the hydraulic fluid line  354 , such as, for example, in the instance where the hydraulic fluid level falls below a predetermined level. To this end, a one-way valve  372  is in fluid communication with the reservoir  368  and the hydraulic fluid line  354 . One-way valve  372  is operably disposed between the reservoir  368  and the hydraulic fluid line  354 , as best seen in  FIG. 5B . The combination of reservoir  368  and one-way valve  372  ensures that an specific working range of pressure is maintained within the hydraulic fluid line  354  such that a specific sealing or closure pressure (e.g., sealing or closure pressure approximately equal to 3 kg/cm 2  to about 16 kg/cm 2 ) is maintained at the jaw members  310  and  320  when jaw members  310  and  320  are in the clamping position. 
     For a more detailed description of hydraulic mechanism  350  (including operative components associated therewith), reference is made to commonly-owned U.S. patent application Ser. No. 12/211,205 filed on Sep. 16, 2008. 
     Turning now to  FIGS. 6A and 6B , and initially with reference to  FIG. 6A , end effector  300  including jaw members  310  and  320  configured for use with the bipolar forceps  10   a  is illustrated. Jaw members  310  and  320  are similar to that of jaw members  110  and  120 , respectively. Accordingly, only those features that are unique to the operation of the bipolar forceps  10   a  and jaw members  310  and  320  are described in further detail. 
     A biasing component in the form of a bellows  374  of suitable proportion is operably coupled to and associated with each of the jaw members  310  and  320 . More particularly, bellows  374  includes respective top and bottom portions  376  and  378  that are operably secured (by any suitable method) to proximal ends  317   b  and  327   b,  respectively. Bellows  374  is in fluid communication with the hydraulic fluid line  354  and is configured to store a quantity of the hydraulic fluid therein. Bellows  378  moves in a plane “D-D” that is orthogonal to the longitudinal axis “A-A” from a non-expanded or compressed condition or state wherein the jaw members  310  and  320  are in the open position ( FIG. 6A ) to an expanded or non-compressed condition wherein the jaw members  310  and  320  are in the clamping position ( FIG. 6B ). Referring to  FIGS. 7A and 7B , and initially with reference to  FIG. 7A , an alternate embodiment a biasing component configured for use with the jaw members  310  and  320  is illustrated and is in the form of a piston  384 . 
     Piston  384  is of suitable proportion and operably couples to each of the jaw members  310  and  320 . More particularly, piston  384  includes respective top and bottom portions  386  and  388  that are operably secured to proximal ends  317   b  and  327   b,  respectively. More particularly, top portion  386  of the piston  384  includes a crankshaft  390  that is operably coupled (by any suitable coupling method(s)) to the proximal end  317   b  of jaw member  310 . Likewise, bottom portion  388  of the piston  384  includes a crankshaft  392  that is operably coupled (by any suitable coupling method(s)) to the proximal end  327   b  of jaw member  320 . Piston  384  is in fluid communication with the hydraulic fluid line  354  and is configured to store a quantity of the hydraulic fluid therein. Crankshafts  390  and  392  of the piston  384  move in a plane “E-E” that is orthogonal to the longitudinal axis “A-A” from a non-expanded condition or state wherein the jaw members  310  and  320  are in the open position ( FIG. 7A ) to an expanded condition wherein the jaw members  310  and  320  are in the clamping position ( FIG. 7B ). 
     Operation of the bipolar forceps  10   a  with the end effector  300  is described. In use, initially jaw members  310  and  320  are biased in an opened position (see  FIGS. 6A and/or 7A , for example). Once tissue is positioned between the jaw members  310  and  320 , the movable handle  40  is moved proximally causing the drive assembly  330  to cause the plunger  362  to move distally within the main housing  352 . 
     With respect to the embodiment illustrated in  FIG. 6B , this distal movement of the plunger  362  causes the pressure in the hydraulic fluid line to build up, which, turn, causes the bellows  374  to move from the non-expanded condition to the expanded condition, which, in turn, causes both of the jaw members  310  and  320  to move toward each other such that tissue is grasped between the jaw members  310  and  320  ( FIG. 6B ). 
     Alternatively, and with respect to the embodiment illustrated in  FIG. 7B , the distal movement of the plunger  362  causes the pressure in the hydraulic fluid line to build up, which, turn, causes the crankshafts  390  and  392  of the piston  384  to move from the non-expanded condition to the expanded condition, this, in turn, causes both of the jaw members  310  and  320  to move toward each other such that tissue is grasped between the jaw members  310  and  320  ( FIG. 7B ). 
     HDR  350  including bellows  374  or piston  384  is configured to generate the necessary sealing or closure force at the jaw members  310  and  320 . The combination of movable handle  40  and HDR  350  including either bellows  374  or piston  384  provides a consistent, uniform tissue effect, e.g., tissue seal. Moreover, the combination of movable handle  40  and HDR  350  including either bellows  374  or piston  384  provides an additional mechanical advantage at the jaws  310  and  320 . More particularly, the frictional losses that are typically associated with conventional forceps when a drive rod is translated within a shaft is offloaded and/or diminished. 
     Turning now to  FIGS. 8A and 8B , and initially with reference to  FIG. 8A , an end effector  400  including jaw members  410  and  420  configured for use with the bipolar forceps  10   a  is illustrated. Jaw members  410  and  420  are similar to that of jaw members  110  and  120 , respectively. Accordingly, only those features that are unique to the operation of the bipolar forceps  10   a  and jaw members  410  and  420  are described in further detail. 
     Each of the jaw members  410  and  420  includes a respective seal plate  418  and  428 . A distinguishing factor of the jaw members  410  and  420  when compared to the previously described jaw members, e.g., jaw members  110  and  120 , is that the seal plates  418  and  428  are movable with respect to a respective jaw housing  417  and  427 . More particularly, in the embodiments illustrated in  FIGS. 8A and 8B , after tissue is positioned between the jaw members  410  and  420 , the seal plates  418  and  428  are caused to move toward each other such that a specific closure force is achieved at the seal plates  418  and  418  while the seal plates  418  and  428  are in the clamping position and tissue is grasped therebetween. To this end, each of the seal plates  418  and  428  are movably secured or coupled (via any suitable securement or coupling method) to a respective jaw member  410  and  420 . In the illustrated embodiment, the jaw members  410  and  420  are fixedly secured to each other. That is, unlike the previously described jaw members, e.g., jaw members  110  and  120 , jaw members  410  and  420  are not pivotably coupled to each other. In certain instances, however, the jaw members  410  and  420  may be pivotably coupled to each other, such as, for example, via one or more coupling methods previously described, e.g., via a pivot pin  111  that is associated with the end effector  400  and/or shaft  12 . 
     Jaw members  410  and  420  include a respective heat activated, pneumatic activated, or hydraulic activated (or combination thereof) biasing component in the form of a bellows  412  and  422 . In the embodiment illustrated in  FIGS. 9A and 9B , the respective bellows  412  and  422  are operably positioned adjacent a respective seal plate  418  and  428 . More particularly, the bellows  412  and  422  are operably positioned beneath the respective seal plate  418  and  428  and in operative communication with a respective driving mechanism, e.g., a hydraulic drive mechanism  350 , a pneumatic drive mechanism  360  and an electromechanical drive mechanism  370 . 
     In the instance where the bellows  412  and  422  are hydraulically activated, hydraulic mechanism  350  may be utilized to activate each of the bellows  412  and  422 . More particularly, and in this instance, the hydraulic fluid line  354  may be operably disposed on each of the jaw members  410  and  420  and in fluid communication with a respective bellows  412  and  422 . Accordingly, when the movable handle  40  is moved proximally, the respective bellows  412  and  422  on jaw members  410  and  420  expand, which, in turn, cause the respective seal plates to expand such that tissue is grasped therebetween and subsequently sealed. 
     In the instance where the bellows  412  and  422  are pneumatically activated, a pneumatic mechanism  360  may be utilized to activate each of the bellows  412  and  422 . More particularly, and in this instance, a pneumatic fluid line (not shown) may be operably disposed on each of the jaw members  410  and  420  and in fluid communication with a respective bellows  412  and  422 . Accordingly, when the movable handle  40  is moved proximally, the respective bellows  412  and  422  on jaw members  410  and  420  expand, which, in turn, causes the respective seal plates to expand such that tissue is grasped therebetween and subsequently sealed. 
     In the instance where the bellows  412  and  422  are heat-activated, an electromechanical mechanism  370  may be utilized to activate each of the bellows  412  and  422 . More particularly, and in this instance, an electrical cable, e.g., cable  310 , may be operably disposed on each of the jaw members  410  and  420  and in electrical communication with a respective bellows  412  and  422 . Bellows  412  and  422  may be made from a shape memory alloy (Nitinol). More particularly, the bellows will have a cold forged state that corresponds to an expanded position. Accordingly, when a current is applied to the bellows  412  and  422 , the bellows  412  and  422  “heat-up” and transition to the cold forged state, i.e., expanded condition, which, in turn, causes the respective seal plates to expand such that tissue is grasped therebetween and subsequently sealed. 
     Operation of the bipolar forceps  10   a  with the end effector  400  is described. For illustrative purposes, operation of bipolar forceps  10   a  including end effector  400  is described in terms of use with HDR  350 . 
     In use, initially jaw members  410  and  420  are in a substantially open position (see  FIG. 8A ). Tissue is positioned between the jaw members  410  and  420  including their respective seal plates  418  and  428 , the movable handle  40  is moved proximally causing the drive assembly  330  to cause the plunger  362  to move distally within the main housing  352 . This distal movement of the plunger  362  causes the pressure in the hydraulic fluid line to build up, which, in turn, causes the bellows  412  and  422  to expand. The bellows  412  and  422  move from the non-expanded condition to the expanded condition such that tissue is grasped between the jaw members  310  and  320  ( FIG. 6B ). 
     HDR  350  (including bellows  412  and  422 ) is configured to generate the necessary sealing or closure force at the jaw members  410  and  420 . The combination of movable handle  40  and HDR  350  (including bellows  412  and  422 ) provides a consistent, uniform tissue effect, e.g., tissue seal. Moreover, the combination of movable handle  40  and HDR  350  provides an additional mechanical advantage at the jaw members  410  and  420 . More particularly, the frictional losses that are typically associated with conventional forceps when a drive rod is translated within a shaft is offloaded and/or diminished. An advantage of jaw members  410  and  420  that utilize respective bellows  412  and  422 , when compared to conventional jaw members, is that the bellows  412  and  422  conform to tissue disposed between the jaw members  110  and  120 . 
     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, other spring mechanisms such as, for example, foam, spring washers, and so forth, may be operably associated with any of the aforementioned configurations of end effectors including their respective jaw members, e.g., end effector  100  including jaw members  110  and  120 , and utilized to generate a closure or sealing force at the jaw members. 
     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.