Abstract:
A method for manufacturing an end effector assembly is provided. The method includes grasping a gap-setting gauge between first and second jaw members moveable relative to one another about a pivot between a first, spaced-apart position and a second position proximate tissue and setting the first and second jaw members such that in the approximated position the jaw members cooperate to define a gap distance between the jaw members equivalent to the thickness of the gap-setting gauge such that when positioning tissue between the jaw members full approximation of the jaws is limited to the gap distance.

Description:
BACKGROUND 
     The present disclosure relates to surgical instruments and, more particularly, to a surgical tissue sealing for grasping, sealing and/or dividing tissue. 
     TECHNICAL FIELD 
     A forceps is a pliers-like instrument which relies on mechanical action between its jaws to grasp, clamp and constrict vessels or tissue. Electrosurgical forceps utilize both mechanical clamping action and electrical energy to affect hemostasis by heating tissue and blood vessels to coagulate and/or cauterize tissue. Certain surgical procedures require more than simply cauterizing tissue and rely on the unique combination of clamping pressure, precise electrosurgical energy control and gap distance (i.e., distance between opposing jaw members when closed about tissue) to “seal” tissue, vessels and certain vascular bundles. Typically, once a vessel is sealed, the surgeon has to accurately sever the vessel along the newly formed tissue seal. Accordingly, many vessel sealing instruments have been designed which incorporate a knife or blade member that effectively severs the tissue after forming a tissue seal. 
     SUMMARY 
     According to one aspect of the present disclosure, a method for manufacturing an end effector assembly is provided. The method includes grasping a gap-setting gauge between first and second jaw members moveable relative to one another about a pivot between a first, spaced-apart position and a second position proximate tissue and setting the first and second jaw members such that in the approximated position the jaw members cooperate to define a gap distance between the jaw members equivalent to the thickness of the gap-setting gauge such that when positioning tissue between the jaw members full approximation of the jaws is limited to the gap distance. 
     According to another aspect of the present disclosure, a method for manufacturing an end effect assembly is provided. The method includes grasping a gap-setting gauge between first and second jaw members moveable relative to one another about a pivot between a first, spaced-apart position and a second position proximate tissue, inserting an adjustable stop member into at least one of the first and second jaw members, setting the first and second jaw members such that in the approximated position the jaw members cooperate to define a gap distance between the jaw members equivalent to the thickness of the gap-setting gauge, and securing the adjustable stop member to the at least one of the first and second jaw members such that when positioning tissue between the jaw members full approximation of the jaws is limited to the gap distance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the present disclosure are described herein with reference to the drawings wherein: 
         FIG. 1  is a front, perspective view of an endoscopic surgical instrument configured for use in accordance with the present disclosure; 
         FIG. 2  is a front, perspective view of an open surgical instrument configured for use in accordance with the present disclosure; 
         FIG. 3  is an enlarged, front, cross-sectional view of one embodiment of an end effector assembly configured for use with the surgical instrument of  FIG. 1  or  2 ; 
         FIG. 4  is an enlarged, side, cross-sectional view of one embodiment of an end effector assembly configured for use with the surgical instrument of  FIG. 1  or  2 . 
         FIG. 5  is an enlarged, side, cross-sectional view of one embodiment of an end effector assembly configured for use with the surgical instrument of  FIG. 1  or  2 ; 
         FIG. 6  is an enlarged, side, cross-sectional view of one embodiment of an end effector assembly configured for use with the surgical instrument of  FIG. 1  or  2 ; 
         FIG. 7A  is an enlarged, side, cross-sectional view of one embodiment of an end effector assembly configured for use with the surgical instrument of  FIG. 1  or  2 ; 
         FIG. 7B  is an enlarged view of the area of detail  7 B of the end effector of  FIG. 7A ; 
         FIG. 7C  is an enlarged view of the area of detail  7 B of another embodiment of the end effector of  FIG. 7A ; and 
         FIG. 8  is an enlarged, side, cross-sectional view of one embodiment of an end effector assembly configured for use with the surgical instrument of  FIG. 1  or  2 . 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical elements. As used herein, the term “distal” refers to the portion that is being described which is further from a user, while the term “proximal” refers to the portion that is being described which is closer to a user. 
     Referring now to  FIGS. 1 and 2 ,  FIG. 1  depicts a forceps  10  for use in connection with endoscopic surgical procedures and  FIG. 2  depicts an open forceps  10 ′ contemplated for use in connection with traditional open surgical procedures. For the purposes herein, either an endoscopic instrument, e.g., forceps  10 , or an open instrument, e.g., forceps  10 ′, may be utilized in accordance with the present disclosure. Obviously, different electrical and mechanical connections and considerations apply to each particular type of instrument; however, the novel aspects with respect to the end effector assembly and its operating characteristics remain generally consistent with respect to both the open and endoscopic configurations. 
     Turning now to  FIG. 1 , an endoscopic forceps  10  is provided defining a longitudinal axis “X-X” and including a housing  20 , a handle assembly  30 , a rotating assembly  70 , a trigger assembly  80  and an end effector assembly  100 . Forceps  10  further includes a shaft  12  having a distal end  14  configured to mechanically engage end effector assembly  100  and a proximal end  16  that mechanically engages housing  20 . Forceps  10  also includes electrosurgical cable  610  that connects forceps  10  to a generator (not shown) or other suitable power source, although forceps  10  may alternatively be configured as a battery powered instrument. Cable  610  includes a wire (or wires) (not shown) extending therethrough that has sufficient length to extend through shaft  12  in order to provide electrical energy to at least one of the jaw members  110  and  120  of end effector assembly  100 . 
     With continued reference to  FIG. 1 , handle assembly  30  includes fixed handle  50  and a moveable handle  40 . Fixed handle  50  is integrally associated with housing  20  and handle  40  is moveable relative to fixed handle  50 . Rotating assembly  70  is rotatable in either direction about a longitudinal axis “X-X” to rotate end effector  100  about longitudinal axis “X-X.” Housing  20  houses the internal working components of forceps  10 . 
     End effector assembly  100  is shown attached at a distal end  14  of shaft  12  and includes a pair of opposing jaw members  110  and  120 . Each of jaw members  110  and  120  includes an opposed electrically conductive tissue sealing surface  112 ,  122 , respectively. End effector assembly  100  is designed as a unilateral assembly, i.e., where jaw member  120  is fixed relative to shaft  12  and jaw member  110  is moveable about pivot  103  relative to shaft  12  and fixed jaw member  120 . However, end effector assembly  100  may alternatively be configured as a bilateral assembly, i.e., where both jaw member  110  and jaw member  120  are moveable about a pivot  103  relative to one another and to shaft  12 . In some embodiments, a knife assembly (not shown) is disposed within shaft  12  and a knife channel (not shown) is defined within one or both jaw members  110 ,  120  to permit reciprocation of a knife blade (not shown) therethrough, e.g., via activation of trigger  82  of trigger assembly  80 . The particular features of end effector assembly  100  will be described in greater detail hereinbelow. 
     Continuing with reference to  FIG. 1 , moveable handle  40  of handle assembly  30  is ultimately connected to a drive assembly (not shown) that, together, mechanically cooperate to impart movement of jaw members  110  and  120  between a spaced-apart position and an approximated position to grasp tissue disposed between sealing surfaces  112  and  122  of jaw members  110 ,  120 , respectively. As shown in  FIG. 1 , moveable handle  40  is initially spaced-apart from fixed handle  50  and, correspondingly, jaw members  110 ,  120  are in the spaced-apart position. Moveable handle  40  is depressible from this initial position to a depressed position corresponding to the approximated position of jaw members  110 ,  120 . 
     Referring now to  FIG. 2 , an open forceps  10 ′ is shown including two elongated shafts  12   a  and  12   b , each having a proximal end  16   a  and  16   b , and a distal end  14   a  and  14   b , respectively. Similar to forceps  10  ( FIG. 1 ), forceps  10 ′ is configured for use with end effector assembly  100 . More specifically, end effector assembly  100  is attached to distal ends  14   a  and  14   b  of shafts  12   a  and  12   b , respectively. As mentioned above, end effector assembly  100  includes a pair of opposing jaw members  110  and  120  that are pivotably connected about a pivot  103 . Each shaft  12   a  and  12   b  includes a handle  17   a  and  17   b  disposed at the proximal end  16   a  and  16   b  thereof. Each handle  17   a  and  17   b  defines a finger hole  18   a  and  18   b  therethrough for receiving a finger of the user. As can be appreciated, finger holes  18   a  and  18   b  facilitate movement of the shafts  12   a  and  12   b  relative to one another that, in turn, pivots jaw members  110  and  120  from an open position, wherein the jaw members  110  and  120  are disposed in spaced-apart relation relative to one another, to a closed position, wherein the jaw members  110  and  120  cooperate to grasp tissue therebetween. 
     A ratchet  30 ′ may be included for selectively locking the jaw members  110  and  120  relative to one another at various positions during pivoting. It is envisioned that the ratchet  30 ′ may include graduations or other visual markings that enable the user to easily and quickly ascertain and control the amount of closure force desired between the jaw members  110  and  120 . 
     With continued reference to  FIG. 2 , one of the shafts, e.g., shaft  12   b , includes a proximal shaft connector  19  which is designed to connect the forceps  10 ′ to a source of electrosurgical energy such as an electrosurgical generator (not shown). Proximal shaft connector  19  secures an electrosurgical cable  610 ′ to forceps  10 ′ such that the user may selectively apply electrosurgical energy to the electrically conductive sealing surfaces  112  and  122  ( FIG. 1 ) of jaw members  110  and  120 , respectively, as needed. 
     Forceps  10 ′ may further include a knife assembly (not shown) disposed within either of shafts  12   a ,  12   b  and a knife channel (not shown) defined within one or both jaw members  110 ,  120  to permit reciprocation of a knife blade (not shown) therethrough. 
     Turning now to  FIG. 3 , end effector assembly  100 , including jaw members  110  and  120  is configured for use with either instrument  10  or instrument  10 ′, discussed above, or any other suitable surgical instrument. However, for purposes of simplicity and consistency, end effector assembly  100  will be described hereinbelow with reference to instrument  10  only. 
     Tissue sealing procedures involve more than simply cauterizing tissue. In order to effect a proper seal in vessels or tissue, it has been determined that a variety of mechanical and electrical parameters should be accurately controlled: the pressure applied to the tissue; the gap distance between the electrodes (e.g., distance between opposing jaw members when closed about tissue); and amount of energy applied to tissue. In embodiments, the present disclosure provides for jaw members  110  and  120  that when fully approximated define a gap distance “G” from about 0.001 inches to about 0.006 inches as well as method for manufacturing the same. However, other gap distances are also contemplated by the present disclosure. 
     As shown in  FIG. 3 , each of the jaw members  110  and  120  includes a jaw housing  111  and  121 , respectively. The sealing surfaces  112  and  122  are coupled to the housings  111  and  121  by overmolding or filling the housing  111  and  121  with a suitable material  115  and  125  that may assist in securing the sealing surfaces  112  and  122  thereto. The material  115  and  125  may be any suitable dielectric or insulating material that may be heat-staked through the housing  111  and  121  as described in further detail below. The housings  111  and  121  include one or more openings  113   a  and  113   b  and  123   a  and  123   b , respectively, which are defined therein and are configured to received a material  115  and  125  therethrough for securing the materials  115  and  125  to the housing  111  and  121 , respectively, as described in more detail below. 
     This configuration in combinations with any of the embodiments disclosed below in  FIGS. 5-8  may also be used to set a desired gap distance “G.” During assembly of the jaw members  110  and  120 , the jaw members  110  and  120  grasp a gap-setting gauge  116  that provides for a desired gap distance “G.” The material  115  and  125  is then heat staked on both sides of the housings  111  and  121 , ultrasonically welded or otherwise secured through the openings  113   a ,  113   b ,  123   a ,  123   b  as the jaw members  110  and  120  grasp the gap-setting gauge  116  to permanently set the sealing surfaces  112  and  122  within the jaw members  110  and  120 , respectively. The material  115  and  125  maintains gaps  127   a  and  127   b  within the housings  111  and  121 , respectively. The gaps  127   a  and  127   b  allow for movement of the material  115  and  125  as well as the sealing surfaces  112  and  122  during the setting process to set the desired gap distance “G.” 
     The jaw members  110  and  120  may be pivotally secured via a pin  117 . Once jaw members  110  and  120  are disposed over the gap gauge  116 , the pin  117  may be welded, flared, riveted, or otherwise secured to secure the jaw members  110  and  120 . 
       FIG. 4  shows an embodiment of setting the sealing surfaces  112  and  122  within the jaw members  110  and  120 . The sealing surfaces  112  and  122  are coupled to the housings  111  and  121  by an adhesive material  236 . The material  236  may be any liquid or amorphous material similar to the material  136  described above. 
     During assembly of the jaw members  110  and  120 , the material  236  is deposited (e.g., injected) into the housings  111  and  121  and the jaw members  110  and  120  grasp the gap-setting gauge  116 . The jaw members  110  and  120  are then fully approximated (e.g., handle  40  is fully squeezed and locked into handle assembly  30 ). The material  236  is allowed to cure and the jaw members  110  and  120  are now configured to provide a desired gap distance “G” therebetween. As the jaw members  110  and  120  grasp the gap-setting gauge  116 , the material  236  solidifies to permanently set the sealing surfaces  112  and  122  within the jaw members  110  and  120 . This configuration in combinations with any of the embodiments disclosed below in  FIGS. 5-8  may also be used to set a desired gap distance “G.” 
       FIG. 5  shows another embodiment of a stop member configuration setting a gap distance “G” between the jaw members  110  and  120 . As shown, the jaw member  110  includes a fixed stop member  130  disposed at a proximal portion  132  (e.g., closer to the pivot pin  117 ) of the jaw member  110 . In some embodiments, the stop member  130  may be disposed on the jaw member  120 . The stop member  130  is configured to be inserted into a cavity  134  defined within the jaw member  120 . To obtain a desired gap distance “G,” during assembly of the jaw members  110  and  120 , the jaw members  110  and  120  grasp the gap-setting gauge  116  that provides for a desired gap distance “G.” A setting material  136  is deposited into the cavity  134  to a sufficient level such that once the material  136  is solidified, it prevents approximation of the jaw members  110  and  120  beyond the gap distance “G.” Once the material  136  has solidified, the jaw members  110  and  120  are permanently set to the desired gap distance “G” when in closed configuration as the travel distance for the stop member  130  is limited by the solidified material  136  (e.g., the jaw members  110  and  120  are able to freely rotate but bottom out at the appropriate gap distance “G” when the jaw member  110  comes in contact with the stop member  130 ). 
     The material  136  may be any liquid or amorphous material that solidifies upon deposition into the cavity  134 . In some embodiments, the material  136  may be any material or combination of materials (e.g., epoxy) that may change its phase after deposition, such that the material  136  is initially in a liquid phase and then transitions into a solid phase. 
     In some embodiments, the material  136  may be a liquid material that may be solidified by one of the following processes which include, but are not limited to, room temperature vulcanization, a thermosetting polymer reaction (e.g., epoxy), curing (e.g., anaerobic or ultra-violet), and combinations thereof. The material  136  may be a polymer, which may include, but not limited to, polyesters, silicones, rubbers, epoxies, nylons, polyphthalamides, liquid crystal polymers, and combinations thereof. 
       FIG. 6  shows another embodiment of a stop member configuration for setting a gap distance “G” between the jaw members  110  and  120 . As shown, the jaw member  120  includes a stop member  230  disposed at a proximal portion  232  (e.g., closer to the pivot pin  117 ) of the jaw member  120 . The stop member  230  may be disposed on the jaw member  110  and is configured to be inserted into an aperture  234  defined in the jaw member  120 . To obtain a desired gap distance “G,” during assembly of the jaw members  110  and  120 , the jaw members  110  and  120  grasp the gap-setting gauge  116  that provides for a desired gap distance “G” and the stop member  230  is inserted through aperture  234 . The stop member  230  is secured within the aperture such that the jaw members  110  and  120  are permanently set to the desired gap distance “G” when in the closed configuration (e.g., the jaw members  110  and  120  are able to freely rotate but bottom out at the appropriate gap distance “G” when the jaw member  110  comes in contact with the stop member  230 ). 
       FIGS. 7A-7C  shows another embodiment of setting a gap distance “G” between the jaw members  110  and  120 . As shown, the jaw member  110  includes an adjustable stop member  330  disposed at a proximal portion  132  (e.g., closer to the pivot pin  117 ) of the jaw member  110 . In some embodiments, the stop member  330  may be disposed on the jaw member  120 . The stop member  330  is configured to be inserted into an aperture  334  through the jaw member  120 . Each of the stop member  330  and aperture  334  include one or more surface features  332  and  336 , respectively. The surface features  332  and  336  are configured to interlockingly engage with each other, such that the stop member  330  may only be inserted into the aperture  334  and is locked therein preventing extraction thereof. The stop member  330  is removably coupled (e.g., via peelable adhesive) to the jaw member  110  allowing the jaw members  110  and  120  to open, retaining the stop member  330  within the jaw member  120 . Suitable surface features  332  and  336  include, but are not limited to, barbs, hooks, latches, protrusions, leaves, teeth and/or combinations thereof. In another embodiment, as shown in  FIG. 7C , the aperture  334  may have a straight interference fit, without any surface features  336 . Thus, the stop member  330  is inserted into the aperture  334  to a desired depth depending on the thickness of the gap-setting gauge  116 . Once inserted to a desired depth, the surface features  332  and  336  interlock and set a specific gap “G.” 
     To obtain a desired gap distance “G,” during assembly of the jaw members  110  and  120 , the jaw members  110  and  120  grasp the gap-setting gauge  116  therebetween and pressure is applied to the jaw members  110  and  120  until the surface features  332  and  336  engage each other. If more than one set of surface features  336  are used, the jaw members  110  and  120  may be approximated until a desired gap distance “G” is achieved. 
       FIG. 8  shows another embodiment of a stop member configuration for setting a gap distance “G” between the jaw members  110  and  120 . As shown, the jaw member  120  includes a stop member  430  disposed at a proximal portion  232  (e.g., closer to the pivot pin  117 ) of the jaw member  120 . The stop member  430  may be disposed on the jaw member  120  and is configured to be inserted into an aperture  434  defined in the jaw member  120 . The stop member  430  includes a threaded shaft  432  configured to threadably interface with the aperture  434 . The stop member  430  may be adjusted to a desired height by rotating the stop member  430  in either clockwise or counterclockwise direction move the stop member  430  into or out of the aperture  434 , thereby adjusting the gap distance “G.” To obtain a desired gap distance “G,” during assembly of the jaw members  110  and  120 , the jaw members  110  and  120  grasp the gap-setting gauge  116  that provides for a desired gap distance “G” and the stop member  430  is threadably inserted through aperture  434 . The stop member  430  is secured within the aperture such that the jaw members  110  and  120  are permanently set to the desired gap distance “G” when in the closed configuration (e.g., the jaw members  110  and  120  are able to freely rotate but bottom out at the appropriate gap distance “G” when the jaw member  110  comes in contact with the stop member  430 ). 
     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. 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.