Abstract:
An end effector assembly includes a pair of opposing jaw members. One or more of the jaw members includes a support base, an electrical jaw lead, a sealing plate, and a ceramic layer. The sealing plate is coupled to the electrical jaw lead and mounted to the support base. The sealing plate includes a tissue engaging surface, an opposing surface, and a series of depressions formed within the opposing surface and projecting from the tissue engaging surface. The ceramic layer is deposited atop each of the series of depressions. The combination of the depressions that project from the tissue engaging surface and their ceramic layers form a corresponding series of nonconductive stop members for controlling the separation distance between opposing jaw members when closed about tissue.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to an apparatus for performing an endoscopic electrosurgical procedure. More particularly, the present disclosure relates to an apparatus for performing an endoscopic electrosurgical procedure that employs an endoscopic electrosurgical apparatus that includes an end effector assembly configured for use with variously-sized access ports. 
         [0003]    2. Background of the Related Art 
         [0004]    Electrosurgical apparatuses (e.g., electrosurgical forceps) are well known in the medical arts and typically include a handle, a shaft and an end effector assembly operatively coupled to a distal end of the shaft that is configured to manipulate tissue (e.g., grasp and seal tissue). Electrosurgical forceps utilize both mechanical clamping action and electrical energy to effect homeostasis by heating the tissue and blood vessels to coagulate, cauterize, fuse, seal, cut, desiccate, and/or fulgurate tissue. 
         [0005]    As an alternative to open electrosurgical forceps for use with open surgical procedures, many modern surgeons use endoscopes and endoscopic electrosurgical apparatus (e.g., endoscopic forceps) for remotely accessing organs through smaller, puncture-like incisions. As a direct result thereof, patients tend to benefit from less scarring, less pain, and reduced healing time. Typically, the endoscopic forceps are inserted into the patient through one or more various types of cannulas or access ports (typically having an opening that ranges from about five millimeters to about fifteen millimeters) that has been made with a trocar; as can be appreciated, smaller cannulas are usually preferred. 
         [0006]    Endoscopic forceps that are configured for use with small cannulas (e.g., cannulas less than five millimeters) may present design challenges for a manufacturer of endoscopic instruments. 
       SUMMARY 
       [0007]    An end effector assembly includes a pair of opposing jaw members. One or more of the jaw members includes a support base, an electrical jaw lead, a sealing plate, and a ceramic layer. The sealing plate is coupled to the electrical jaw lead and mounted to the support base. The sealing plate includes a tissue engaging surface, an opposing surface, and a series of depressions formed within the opposing surface and projecting from the tissue engaging surface. One or more of the series of depressions may have a cross-sectional area that is one or more of circular in shape, hemispherical in shape, and rectangular in shape. In embodiments, two or more of the depressions of the series of depressions have different cross-sections. The series of depressions is formed by one or more of stamping, bending, and machining. 
         [0008]    The ceramic layer is deposited atop each of the series of depressions. The ceramic layer may be vapor deposited onto the series of depressions. The ceramic layer may have a thickness between about 10 angstroms and about 500 angstroms. The combination of the depressions that project from the tissue engaging surface and the ceramic layer form a corresponding series of nonconductive stop members for controlling the separation distance between opposing jaw members when closed about tissue. 
         [0009]    In one aspect, a method of manufacturing a sealing plate of an end effector assembly includes providing one or more jaw members having a support base, an electrical jaw lead, and a sealing plate coupled to the electrical jaw lead and mounted to the support base. The sealing plate includes a tissue engaging surface and an opposing surface. The method includes forming a series of depressions within the opposing surface of the sealing plate such that the series of depressions project from the tissue engaging surface. On step includes depositing a ceramic layer atop each of the series of depressions to form a corresponding series of nonconductive stop members for controlling the separation distance between opposing jaw members when closed about tissue. In one manner, the depositing step involves vapor deposition in a high volume vacuum chamber. The forming step may involve one or more of stamping, bending, and machining. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which: 
           [0011]      FIG. 1  is a perspective view of an endoscopic bipolar forceps in accordance with an embodiment of the present disclosure; 
           [0012]      FIG. 2  is a perspective view of an open bipolar forceps in accordance with an embodiment of the present disclosure; 
           [0013]      FIGS. 3A and 3B  are perspective views of opposing jaw members according to an embodiment of the present disclosure; 
           [0014]      FIGS. 4A and 4B  are exploded views of the opposing jaw members of  FIGS. 3A and 3B  respectively; 
           [0015]      FIG. 5A  is a perspective view of a sealing plate according to an embodiment of the present disclosure; and 
           [0016]      FIG. 5B  is a rear, cross-sectional view of the sealing plate of  FIG. 5A . 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Particular embodiments of the present disclosure are described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. 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. 
         [0018]    Like reference numerals may refer to similar or identical elements throughout the description of the figures. As shown in the drawings and described throughout the following description, as is traditional when referring to relative positioning on a surgical instrument, the term “proximal” refers to the end of the apparatus which is closer to the user and the term “distal” refers to the end of the apparatus which is farther away from the user. The term “clinician” refers to any medical professional (i.e., doctor, surgeon, nurse, or the like) performing a medical procedure involving the use of embodiments described herein. 
         [0019]    Turning now to  FIG. 1 , an instrument generally identified as forceps  10  may be used during various surgical procedures and includes a housing  20 , a handle assembly  30 , a rotating assembly  80 , a trigger assembly  70 , and an end effector assembly  100  that mutually cooperate to grasp, seal, and divide tubular vessels and vascular tissues. Forceps  10  includes a shaft  12  that has a distal end  14  dimensioned to mechanically engage the end effector assembly  100  and a proximal end  16  that mechanically engages the housing  20 . The end effector assembly  100  includes opposing jaw members  110  and  120 , which cooperate to effectively grasp tissue for sealing purposes. The jaw members  110  and  120  may be curved to facilitate manipulation of tissue and to provide better “line of sight” for accessing targeted tissues. 
         [0020]    Examples of forceps are shown and described in commonly-owned U.S. application Ser. No. 10/369,894 entitled “VESSEL SEALER AND DIVIDER AND METHOD MANUFACTURING SAME” and commonly owned U.S. application Ser. No. 10/460,926 (now U.S. Pat. No. 7,156,846) entitled “VESSEL SEALER AND DIVIDER FOR USE WITH SMALL TROCARS AND CANNULAS. 
         [0021]    With regard to  FIG. 2 , an open forceps  200  for use with various surgical procedures is shown. Forceps  200  includes a pair of opposing shafts  212   a  and  212   b  having an end effector assembly  230  attached to the distal ends  216   a  and  216   b  thereof, respectively. End effector assembly  230  is similar in design to end effector assembly  100  and includes pair of opposing jaw members  232  and  234  that are pivotably connected about a pivot pin  265  and that are movable relative to one another to grasp tissue. Each shaft  212   a  and  212   b  includes a handle  215  and  217 , respectively, disposed at the proximal end  214   a  and  214   b  thereof. Each handle  215  and  217  defines a finger hole  215   a  and  217   a,  respectively, therethrough for receiving a finger of the user. Finger holes  215   a  and  217   a  facilitate movement of the shafts  212   a  and  212   b  relative to one another which, in turn, pivot the jaw members  232  and  234  from an open position wherein the jaw members  232  and  234  are disposed in spaced relation relative to one another to a clamping or closed position wherein the jaw members  232  and  234  cooperate to grasp tissue therebetween. 
         [0022]      FIGS. 3A and 3B  are perspective views of opposing jaw members  310  and  320 . Similar to jaw members  110  and  120 , each of the jaw members  310  and  320  include: sealing plates  312  and  322 , respectively; electrical jaw leads  325   a  and  325   b , respectively; and support bases  316  and  326  formed as plastic overmolds. Electrical jaw leads  325   a  and  325   b  supply energy to one or both of the opposing jaw members  310  and  320 . 
         [0023]    Turning to  FIGS. 4A and 4B , the opposing jaw members  310  and  320  include support bases  316  and  326  that extend distally from flanges  313  and  323 , respectively. The support bases  316  and  326  are dimensioned to support insulative plates  319 ′ and  329 ′, which in turn, support electrically conductive sealing plates  312  and  322  thereon. Sealing plates  312  and  322  may be affixed atop the insulative plates  319 ′ and  329 ′, respectively, and support bases  319  and  329 , respectively, in any known manner in the art, snap-fit, over-molding, stamping, ultrasonically welded, etc. The support bases  319  and  329 , insulative plates  319 ′ and  329 ′, and sealing plates  312  and  322  are encapsulated by the outer insulative housings  316  and  326  by way of a subsequent overmolding process. The jaw members  310  and  320  are connected via an ultrasonic weld to electrical jaw leads  325   a  and  325   b,  respectively. 
         [0024]    The jaw members  310  and  320  also include proximal flanges  313  and  323  extending proximally from the support bases  319  and  329 , respectively, each of which includes an elongated angled cam slot  317  and  327 , respectively, defined therethrough. Jaw member  320  includes a series of stop members  390  disposed on the inner facing surface of electrically conductive sealing plate  312  to define a gap between opposing jaw members  310  and  320  during sealing and cutting of tissue. The series of stop members  390  are applied onto the sealing plate  312  during manufacturing. The electrically conductive sealing plates  312  and  322  and the insulator plates  319 ′ and  329 ′ include respective longitudinally-oriented knife slots  315   a,    315   a ′ and  315   b,    315   b ′, respectively, defined therethrough for reciprocation of the knife blade (not shown). 
         [0025]    With reference to  FIG. 5A , a perspective view of sealing plate  500  is shown. Sealing plate  500  is similar to sealing plate  322  described above. As shown, sealing plate  500  has a stainless steel layer  510  and ceramic layer  520 . Like stop members  390 , the ceramic layer  520  provides insulation between opposing jaw members  310 ,  320  (see  FIGS. 3A and 3B ) during sealing and cutting of tissue. Most ceramics are stable at elevated temperatures and usually exhibit low thermal and electrical conductivities. In addition, ceramic materials have high melting points and are resistant to oxidation, corrosion, or other forms of degradation to which metals are usually more prone. 
         [0026]    As best shown in  FIG. 5B , stainless steel layer  510  includes one or more depressions  512  which may be formed by stamping, a process where metal is formed by being pressed with an embossed pattern, bending, a manufacturing process that produces a V-shape, U-shape, or channel shape along a straight axis in ductile materials, or machining, a material-working processes in which power-driven machine tools, such as lathes, milling machines, and drill presses, are used with a sharp cutting tool to mechanically cut the material to achieve the desired geometry. Accordingly, each depression  512  may be any suitable shape including a shape having circular or non-circular cross-sectional areas. As shown, each depression  512  may be substantially hemispheric ally shaped. Stainless steel layer  510  may have a polymer coating to prevent corrosion. The polymer coating may be applied by vapor deposition, heat treatment or any other method that may be used to apply a coating to stainless steel layer  510 . 
         [0027]    Two types of vapor deposition include chemical vapor deposition (“CVD”) and physical vapor deposition (“PVD”). In a typical CVD process, the substrate is exposed to one or more volatile precursors, which react and/or decompose on the substrate surface to produce the desired deposit. Frequently, volatile by-products are also produced, which are removed by gas flow through a reaction chamber. PVD is a variety of vacuum deposition and is a general term used to describe any of a variety of methods to deposit thin films by the condensation of a vaporized form of the material onto various surfaces. This coating method involves purely physical processes such as high temperature vacuum evaporation or plasma sputter bombardment. 
         [0028]    Ceramic layer  520  may be positioned onto the reverse side or top of depressions  512  of the stainless steel layer  510  by vapor deposition, e.g., CVD or PVD. In this instance, the tissue engaging surface or sealing plate  322  of jaw member  320  includes a series of projections that form a structured bore for the ceramic layer  520 . Once the projections are formed, the ceramic layer  520  may be vapor deposited onto the stainless steel layer  510  in a high volume vacuum chamber in order to manufacture sealing plate  500  at a high production rate and reduced expense due to the efficiency associated with vapor deposition. Ceramic layer  520  may have a thickness ranging from 10 angstroms to about 500 angstroms. Sealing plate  500 , which includes stainless steel layer  510  and ceramic layer  520 , may have a thickness ranging from 0.005 inches to 0.008 inches. The resulting effect is that jaw member  320  (or any of the aforementioned jaw members  120 ,  220 ) includes a series of stop members  390  that project from one or both jaw members and maintain a gap of about 0.001 inch to about 0.006 inches therebetween. 
         [0029]    It should be understood that the foregoing description is only illustrative of the present disclosure. Various alternatives and modifications can be devised by those skilled in the art without departing from the disclosure. Accordingly, the present disclosure is intended to embrace all such alternatives, modifications and variances. The embodiments described with reference to the attached drawings are presented only to demonstrate certain examples of the disclosure. Other elements, steps, methods and techniques that are insubstantially different from those described above and/or in the appended claims are also intended to be within the scope of the disclosure.