Abstract:
An end effector assembly for use with an electrosurgical instrument is provided. The electrosurgical instrument includes a handle having a shaft that extends therefrom, an end effector disposed at a distal end of the shaft, at least one electrode operably coupled to the end effector and adapted to couple to a source of electrosurgical energy, a titanium nitride coating covering at least a portion of the electrode, a chromium nitride coating covering at least a portion of the electrode and/or titanium nitride coating, and a hexamethyldisiloxane plasma coating covering at least a portion of the chromium nitride coating.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation in part application of U.S. application Ser. No. 14/926,553, filed on Oct. 29, 2015, the entire contents of which are incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to an electrosurgical instrument and method for sealing tissue. More particularly, the present disclosure relates to an electrosurgical tool including opposing jaw members having sealing plates with improved non-stick coatings and methods for manufacturing the same. 
         [0004]    2. Background of the Related Art 
         [0005]    Electrosurgical forceps utilize mechanical clamping action along with electrical energy to effect hemostasis on the clamped tissue. The forceps (open, laparoscopic or endoscopic) include electrosurgical sealing plates which apply the electrosurgical energy to the clamped tissue. By controlling the intensity, frequency and duration of the electrosurgical energy applied through the sealing plates to the tissue, the surgeon can coagulate, cauterize, and/or seal tissue. 
         [0006]    During an electrosurgical procedure, tissue sealing plates are used to apply electrosurgical energy to tissue. Because the sealing plates conduct electricity, care must be taken to electrically insulate the sealing plates from other electrically conductive components of the electrosurgical forceps and to limit and/or reduce many of the known undesirable effects related to tissue sealing, e.g., flashover, thermal spread, and stray current dissipation. Typically, tissue sealing surfaces are disposed on inner facing surfaces of opposing jaw members such that the tissue sealing surfaces are utilized to seal tissue grasped between the jaw members. Often, the manufacturing of jaw members requires the use of a two-shot molding process that includes a pre-shot overmold of insulative material (e.g., plastic) placed between the underside of the sealing plate and the steel structural support base of the jaw member to provide electrical insulation between the jaw member and the tissue sealing surface. 
         [0007]    In the past, significant efforts have been directed to improvements in electrosurgical instruments and the like, with a view towards providing improved transmission of electrical energy to patient tissue in both an effective manner and to reduce the sticking of soft tissue to the instrument&#39;s surface during application. In general, such efforts have envisioned non-stick surface coatings, such as polymeric materials, e.g. polytetrafluoroethylene (PTFE, commonly sold under the trademark TEFLON®) for increasing the lubricity of the tool surface. However, these materials may interfere with the efficacy and efficiency of hemostasis and have a tendency to release from the instrument&#39;s substrate due to formation of microporosity, delamination, and/or abrasive wear, thus exposing underlying portions of the instrument to direct tissue contact and related sticking issues. In turn, these holes or voids in the coating lead to nonuniform variations in the capacitive transmission of the electrical energy to the tissue of the patient and may create localized excess heating, resulting in tissue damage, undesired irregular sticking of tissue to the electrodes and further degradation of the non-stick coating. 
       SUMMARY 
       [0008]    In an aspect of the present disclosure, an electrosurgical instrument is provided. The electrosurgical instrument includes a handle having a shaft that extends therefrom, an end effector disposed at a distal end of the shaft, at least one electrode operably coupled to the end effector and adapted to couple to a source of electrosurgical energy, a titanium nitride coating covering at least a portion of the electrode, a chromium nitride coating covering at least a portion of the electrode, and a hexamethyldisiloxane plasma coating covering at least a portion of the chromium nitride coating. The chromium nitride coating may be disposed over a portion of the titanium nitride coating or all of the titanium nitride coating. The end effector may include a pair of opposing jaw members. At least one of the jaw members may include a support base and an electrical jaw lead, with the electrode coupled to the electrical jaw lead and the support base. The electrode may include a stainless steel layer and a hexamethyldisiloxane plasma coating may be disposed over at least a portion of the stainless steel layer. 
         [0009]    An electrically insulative layer may be bonded to an underside of the sealing plate. The electrically insulative layer may be formed from a polyimide, a polycarbonate, a polyethylene, and/or any combinations thereof. In aspects, a titanium nitride coating is disposed on a topside of the stainless steel layer of the sealing plate, a chromium nitride coating is disposed over the titanium nitride coating, and the hexamethyldisiloxane plasma coating is disposed over the chromium nitride coating. The chromium nitride coating may be disposed over a portion of the titanium nitride coating or all of the titanium nitride coating. The end effector may additionally include an insulative housing disposed around the support base. A hexamethyldisiloxane plasma coating may also be disposed on the sealing plate and the insulative housing. 
         [0010]    In another aspect of the present disclosure, an end effector for use with an electrosurgical instrument for sealing tissue is provided. The end effector may include a pair of opposing jaw members. At least one of the jaw members includes a support base, an electrical jaw lead, a sealing plate coupled to the electrical jaw lead and the support base, the sealing plate having a stainless steel layer, a titanium nitride coating disposed over at least a portion of the stainless steel layer, a chromium nitride coating disposed over at least a portion of the titanium nitride coating, and a hexamethyldisiloxane plasma coating disposed over at least one of the support base, the sealing plate, or the chromium nitride coating. The chromium nitride coating may be disposed over a portion of the titanium nitride coating or all of the titanium nitride coating. 
         [0011]    The end effector may further include an electrically insulative layer disposed on at least a portion of an underside of the stainless steel layer. The electrically insulative layer may be formed from a polyimide, a polycarbonate, a polyethylene, and/or any combinations thereof. In aspects, a titanium nitride coating is disposed on a topside of the stainless steel layer of the sealing plate, a chromium nitride coating is disposed over at least a portion of the titanium nitride coating, and the hexamethyldisiloxane plasma coating is disposed over the chromium nitride coating. The end effector may additionally include an insulative housing disposed around the support base. A hexamethyldisiloxane plasma coating may also be disposed on the sealing plate and the insulative housing. 
         [0012]    The hexamethyldisiloxane plasma coating may be disposed on each of the support base and the chromium nitride coating. Additionally, or alternatively, the end effector may include an insulative housing disposed around the support base and the hexamethyldisiloxane plasma coating may be disposed on the sealing plate and the insulative housing. 
         [0013]    In another aspect of the present disclosure, a method of manufacturing an end effector assembly for use with an electrosurgical instrument is provided. The method includes forming a sealing plate, assembling a jaw member by affixing the sealing plate to a support base, and applying a hexamethyldisiloxane plasma coating to at least a portion of the assembled jaw member. 
         [0014]    Forming a sealing plate includes stamping at least one sealing plate from a stainless steel sheet. Assembling the jaw member may further include bonding an electrically insulative layer to an underside of the sealing plate and/or overmolding an insulative material about the support base to secure the sealing plate thereto. The method may further include coupling an electrical lead to the sealing plate, the electrical lead configured to connect the sealing plate to an energy source. Additionally, or alternatively, the method may further include applying a titanium nitride coating to at least a portion of the assembled jaw member, applying a chromium nitride coating to at least a portion of the assembled jaw member and/or the titanium nitride coating, and applying a hexamethyldisiloxane plasma coating over at least a portion of the chromium nitride coating. Additionally, or alternatively, the method may further include forming a second seal plate, assembling a second jaw member by affixing the second sealing plate to a second support base, applying a hexamethyldisiloxane plasma coating to at least a portion of the second assembled jaw member, and assembling the end effector assembly by coupling the jaw member to the second jaw member. 
         [0015]    In another aspect of the present disclosure, a method for manufacturing an electrosurgical instrument is provided. The method includes applying a titanium nitride coating to at least a portion of an electrically conductive surface, applying a chromium nitride coating to at least a portion of the titanium nitride coating, assembling the coated electrically conductive surface to a treatment member, and applying a hexamethyldisiloxane plasma coating over at least a portion of the treatment member. The chromium nitride coating may be disposed over a portion of the titanium nitride coating or all of the titanium nitride coating. Assembling the coated electrically conductive surface to the treatment member may include providing a support base to support the electrically conductive surface, and bonding an electrically insulative layer to an underside of the electrically conductive surface. 
         [0016]    The method may further include overmolding an insulative material about the support base to secure the electrically conductive surface thereto. Additionally, or alternatively, the method may further include forming the electrically conductive surface by stamping the electrically conductive surface from a sheet of stainless steel. Additionally, or alternatively, the method may further include coupling an electrical lead to the electrically conductive surface, the electrical lead configured to connect the electrically conductive surface to an energy source. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    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: 
           [0018]      FIG. 1  is a perspective view of an endoscopic bipolar forceps in accordance with an aspect of the present disclosure; 
           [0019]      FIG. 2  is a perspective view of an open bipolar forceps according to an aspect of the present disclosure; 
           [0020]      FIGS. 3A and 3B  are exploded views of opposing jaw members according to an aspect of the present disclosure; 
           [0021]      FIG. 4A  is a front cross sectional view of a sealing plate according to an aspect of the present disclosure; 
           [0022]      FIG. 4B  is a front cross sectional view of a jaw member according to an aspect of the present disclosure; 
           [0023]      FIG. 5  is a flow chart illustrating a method of manufacturing an end effector assembly for use with an electrosurgical instrument according to an aspect of the present disclosure; 
           [0024]      FIG. 6  is a flow chart illustrating a method of manufacturing an electrosurgical instrument according to an aspect of the present disclosure; 
           [0025]      FIGS. 7A and 7B  are exploded views of opposing jaw members according to an aspect of the present disclosure; 
           [0026]      FIG. 8A  is a front cross sectional view of a sealing plate according to an aspect of the present disclosure; 
           [0027]      FIG. 8B  is a front cross sectional view of a jaw member according to an aspect of the present disclosure; 
           [0028]      FIG. 9  is a flow chart illustrating a method of manufacturing an end effector assembly for use with an electrosurgical instrument according to an aspect of the present disclosure; and 
           [0029]      FIG. 10  is a flow chart illustrating a method of manufacturing an electrosurgical instrument according to an aspect of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    Particular aspects of the present disclosure are described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed aspects are merely examples 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. 
         [0031]    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 further 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 aspects described herein. 
         [0032]    As described in more detail below with reference to the accompanying figures, the present disclosure is directed to electrosurgical instruments having a hexamethyldisiloxane (“HMDSO”) plasma coating disposed on at least a portion thereof. The HMDSO plasma coating may be derived from HMDSO feed stock in plasma. For example, and without limitation, if pure argon is the media for the plasma and HMDSO is the feedstock, then the HMDSO plasma coating is polymeric with a structure close to [(CH3)2-Si—O]n. With increasing air content, a gradual change may be caused from organic polydimethylsiloxane-like coatings to inorganic, quartz-like deposits. For simplicity, the coating will be described herein as a HMDSO plasma coating. As described in further detail below, the coating may be further modified by introduction of other gasses or feedstocks. 
         [0033]    In one aspect, the present disclosure is directed to opposing jaw members of a vessel sealer instrument having sealing plates with a HMDSO plasma coating deposited over a chromium nitride (“CrN”) coating. Having a non-stick HMDSO plasma coating disposed on an outer surface of the sealing plate, jaw member, end effector, and/or any other portion of a surgical instrument has many advantages. For instance, HMDSO plasma coating, used in conjunction with CrN coating, operates to reduce the pitting of sealing plates as is common with arcing. The double coating provides durability against electrical and/or mechanical degradation of the sealing plates and the jaw members, as a whole, needed for long-term instrument durability. In particular, the additional HMDSO plasma coating reduces the sticking of tissue to the jaws or the surrounding insulating material of the end effector assembly and/or surgical instrument. 
         [0034]    Another advantage of utilizing the HMDSO plasma coating, in conjunction with a CrN coating, is that the HMDSO plasma coating may be applied so thin as to have no functional effect on any tissue sealing properties. Specifically, the HMDSO plasma coating need not have any insulative effects. In one example, the resulting coating using HMDSO as a feedstock in the plasma is silicone oxide matrix with a functionalized surface, in some instances that of surfaced with —CH3. 
         [0035]    Turning now to  FIG. 1 , an instrument generally identified as forceps  10  is for use with 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  130  that mutually cooperate to grasp, seal, and divide tubular vessels and vascular tissues. Forceps  10  includes a shaft  12  extending from a distal end of the housing  20 . The shaft  12  has a distal end  16  dimensioned to mechanically engage the end effector assembly  130  and a proximal end  14  that mechanically engages the housing  20 . 
         [0036]    The end effector assembly  130  includes opposing jaw members  110  and  120 , which cooperate to effectively grasp tissue for sealing purposes. Both jaw members  110  and  120  pivot relative to one another about a pivot pin (not shown). Alternatively, jaw member  110  may be movable relative to a stationary jaw member  120 , and vice versa. 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. 
         [0037]    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,” the entire contents of each of which are incorporated by reference herein. 
         [0038]    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  includes pair of opposing jaw members  210  and  220  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 and that each define 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 to pivot the jaw members  210  and  220  between an open position, wherein the jaw members  210  and  220  are disposed in spaced relation relative to one another, and a clamping or closed position, wherein the jaw members  210  and  220  cooperate to grasp tissue therebetween. 
         [0039]      FIGS. 3A and 3B  are perspective views of opposing jaw members  310  and  320  according to one aspect of the present disclosure which may be utilized with both endoscopic forceps  10  ( FIG. 1 ) and open forceps  200  ( FIG. 2 ). Similar to jaw members  110  and  120  ( FIG. 1 ) and jaw members  210  and  220  ( FIG. 2 ), each of the jaw members  310  and  320  include: sealing plates  312  and  322  (also referred to herein as electrically conductive plate, conductive plates, and/or electrodes), respectively; electrical jaw leads  325   a  and  325   b , respectively; and support bases  319  and  329  that extend distally from flanges  313  and  323 , respectively. 
         [0040]    Each of sealing plates  312  and  322  include an underside  328   a  and  328   b , respectively, that may include a respective electrically insulative layer  330   a  and  330   b  bonded thereto or otherwise disposed thereon. Electrically insulative layers  330   a  and  330   b  operate to electrically insulate sealing plates  312  and  322 , respectively, from support bases  319  and  329 , respectively. Further, electrically insulative layers  330   a  and  330   b  operate to prevent or slow the onset of corrosion of sealing plates  312  and  322 , respectively, at least on the undersides  328   a ,  328   b  thereof. In one embodiment, electrically insulative layers  330   a  and  330   b  may be formed from polyimide. However, in other embodiments, any suitable electrically insulative material may be utilized, such as polycarbonate, polyethylene, etc. 
         [0041]    Additionally, each of jaw members  310  and  320  include an outer surface  311   a  and  311   b , respectively, that may include a respective chromium nitride (“CrN”) coating  400   a  and/or hexamethyldisiloxane (“HMDSO”) plasma coating  400 b disposed, or otherwise deposited, thereon. CrN coating  400   a  and/or HMDSO plasma coating  400   b  may be disposed on selective portions of either of jaw member  310  and  320 , or may be disposed on the entire outer surfaces  311   a  and  311   b . In one embodiment, CrN coating  400   a  and HMDSO plasma coating  400   b  is disposed on an outer surface  317   a  and/or  317   b  of sealing plates  312  and  322 , respectively. HMDSO plasma coating  400   b , used in conjunction with CrN coating  400   a , operates to reduce the pitting of sealing plates  312  and  322  as is common with arcing. The double coating provides durability against electrical and/or mechanical degradation of the sealing plates  312  and  322  and the jaw members  310  and  320  as a whole, needed for long-term instrument durability. In particular, the additional HMDSO plasma coating  400   b  reduces the sticking of tissue to the jaw members  310  and  320  or the surrounding insulating material. 
         [0042]    Support bases  319  and  329  are configured to support electrically conductive sealing plates  312  and  322  thereon. Sealing plates  312  and  322  may be affixed atop the support bases  319  and  329 , respectively, by any suitable method including but not limited to snap-fitting, overmolding, stamping, ultrasonic welding, etc. The support bases  319  and  329  and sealing plates  312  and  322  are at least partially encapsulated by insulative housings  316  and  326 , respectively, by way of an overmolding process to secure sealing plates  312  and  322  to support bases  319  and  329 , respectively. The sealing plates  312  and  322  are coupled to electrical jaw leads  325   a  and  325   b , respectively, via any suitable method (e.g., ultrasonic welding, crimping, soldering, etc.). Electrical jaw lead  325   a  supplies a first electrical potential to sealing plate  312  and electrical jaw lead  325   b  supplies a second electrical potential to opposing sealing plate  322 . 
         [0043]    Jaw member  320  (and/or jaw member  310 ) may also include a series of stop members  390  disposed on the topside surface  317   a  (the inner facing surface) of sealing plate  312  to facilitate gripping and manipulation of tissue and 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. Some or all of the stop members  390  may be coated with the CrN coating  400   a  and/or the HMDSO plasma coating  400   b , or alternatively may be disposed on top of the CrN coating  400   a  and/or the HMDSO plasma coating  400   b . Further, the sealing plates  312  and  322  may include longitudinally-oriented knife slots  315   a  and  315   b , respectively, defined therethrough for reciprocation of a knife blade (not shown). The electrically insulative layers  330   a  and  330   b  disposed on the undersides  328   a  and  328   b , respectively, of sealing plates  312  and  322 , respectively, allow for various blade configurations such as, for example, T-shaped blades or I-shaped blades that may contact the underside of the sealing plate (and/or insulating layer) during reciprocation through knife slots  315   a ,  315   b . That is, the electrically insulative layers  330   a ,  330   b  operate to protect both the knife blade and the undersides  328   a  and  328   b  of the sealing plates  312  and  322 , respectively, from damage or wearing. Further, in the instance that an electrically conductive knife blade is utilized (e.g., for electric tissue cutting), the electrically insulative layers  330   a ,  330   b  help to electrically insulate the sealing plates  312 ,  322  from the electrically conductive knife blade. 
         [0044]    Turning now to  FIG. 4A , a front cross sectional view of sealing plate  312  is shown and will be described. Sealing plate  312  has a stainless steel layer  317 , an electrically insulative layer  330   a , a CrN coating  400   a , and an HMDSO plasma coating  400   b . Sealing plate  312  may be formed by bonding electrically insulative layer  330   a  to the underside  328   b  of stainless steel layer  317 , coating at least the upper surface  317   a  of the stainless steel layer  317  with a CrN coating  400   a , and coating at least a portion of the CrN coating  400   a  and/or the stainless steel layer  317  with an HMDSO plasma coating  400   b . Bonding electrically insulative layer  330   a  to stainless steel layer  317  may be accomplished by any suitable method including, but not limited to, applying adhesive between electrically insulative layer  330   a  and stainless steel layer  317 , using heat treatment to bond electrically insulative layer  330   a  to stainless steel layer  317 , and/or any combinations thereof. Electrically insulative layer  430   a  may have a thickness ranging from about 0.001 inches to about 0.005 inches. Sealing plate  312 , which includes stainless steel layer  317 , electrically insulative layer  330   a , CrN coating  400   a  and HMDSO plasma coating  400   b , may have a thickness ranging from about 0.005 inches to about 0.010 inches. 
         [0045]    Sealing plate  312  may be formed by bonding a sheet of electrically insulative to a sheet of stainless steel and coating the sheet of stainless steel with at least one of a CrN coating and/or an HMDSO plasma coating. Once the two materials are bonded together, and the stainless steel sheet is coated with one or both of the CrN layer and/or the HMDSO plasma layer, sealing plate  312  may be formed by stamping, machining, or any other suitable method used to form a sealing plate. 
         [0046]    Turning now to  FIG. 4B , a front cross sectional view of jaw member  310  is shown and will be described. Jaw member  310  includes sealing plate  312  having a stainless steel layer  317  and, optionally, an electrically insulative layer  330   a . Sealing plate  312  is affixed to support base  319  via any suitable process. Additionally, with sealing plate  312  secured to support base  319 , the combined sealing plate  312  and support base  319  is secured to insulative housing  316  via any suitable process. A CrN coating  400   a  is disposed over the outer surface  311   a  of the assembled sealing plate  312 , support base  319 , and insulative housing  316 . Additionally, an HMDSO plasma coating  400   b  is disposed over the CrN coating  400   a . As described above, in embodiments it may be useful to coat only a partial outer surface  311   a  of the jaw member  310  or include thicker layers of the CrN coating  400   a  and/or the HMDSO plasma coating  400   b  on different portions of the outer surface  311   a  of the jaw member  310 . 
         [0047]    Additionally, or alternatively, in embodiments, the sealing plates  312  may be coated in the manner described above with respect to  FIG. 4A  and the outer surface  311   a  of the jaw member  310  may also be coated with the CrN coating  400   a  and/or the HMDSO plasma coating  400   b.    
         [0048]    Turning now to  FIG. 5 , a method for manufacturing an HMDSO plasma coated end effector assembly is illustrated and will be described as method  500 . Method  500  begins in step  501  where a CrN coating and/or an HMDSO plasma coating is applied to a sealing plate. 
         [0049]    The HMDSO plasma coating may be applied using a system or process which includes a plasma device that is coupled to a power source, an ionizable media source and a precursor or pre-ionization source similar to the system described in U.S. Patent Publication No. 2013/0116682, filed on Nov. 9, 2011, the contents of which is incorporated by reference herein in its entirety. The power source may include any suitable components for delivering power or matching impedance to the plasma device. More particularly, the power source may be any radio frequency generator or other suitable power source capable of producing electrical power to ignite and sustain the ionizable media to generate a plasma effluent. 
         [0050]    Plasmas are generated using electrical energy that is delivered as either direct current (DC) electricity or alternating current (AC) electricity, in either continuous or pulsed modes, at frequencies from about 0.1 hertz (Hz) to about 100 gigahertz (GHz), including radio frequency bands (“RF”, from about 0.1 MHz to about 100 MHz) and microwave bands (“MW”, from about 0.1 GHz to about 100 GHz), using appropriate generators, electrodes, and antennas. AC electrical energy may be supplied at a frequency from about 0.1 MHz to about 2,450 MHz, in embodiments from about 1 MHz to about 160 MHz. The plasma may also be ignited by using continuous or pulsed direct current (DC) electrical energy or continuous or pulsed RF electrical energy or combinations thereof. Choice of excitation frequency, the workpiece, as well as the electrical circuit that is used to deliver electrical energy to the circuit affects many properties and requirements of the plasma. The performance of the plasma chemical generation, the gas or liquid feedstock delivery system and the design of the electrical excitation circuitry are interrelated, as the choices of operating voltage, frequency and current levels, as well as phase, effect the electron temperature and electron density. Further, choices of electrical excitation and plasma device hardware also determine how a given plasma system responds dynamically to the introduction of new ingredients to the host plasma gas or liquid media. The corresponding dynamic adjustment of the electrical drive, such as via dynamic match networks or adjustments to voltage, current, or excitation frequency may be used to maintain controlled power transfer from the electrical circuit to the plasma. 
         [0051]    Continuing with reference to  FIG. 5 , the sealing plate may be formed of stainless steel which is stamped from a large stainless steel sheet which has already been coated with any of the coatings described herein. Method  500  may optionally also include step  503  where an insulative layer is bonded or otherwise affixed to an underside of the sealing plate. In some aspects, the insulative layer may be bonded to an entire sheet of stainless steel and the sealing plate is stamped from the sheet of stainless steel after the insulative layer is bonded to the sheet of stainless steel. 
         [0052]    In step  505 , the jaw member is assembled. Specifically, in step  505  the coated sealing plate is affixed to a support base and/or an insulative housing. In  505 , the jaw member may be assembled via any suitable process including insert molding. In step  507 , an HMDSO plasma coating is applied to at least a portion of the assembled jaw member. Step  507  may be carried out via plasma coating. The HMDSO plasma coating may be enhanced by the addition of oxygen or fluorine in the plasma and deposition. Any or all of steps  501 - 507 , described above, are repeated to assemble an opposing (second) jaw member. In step  509 , the first assembled jaw member and the second assembled jaw member are assembled to form a coated end effector assembly. That is, the first assembled jaw member is pivotably coupled to the second assembled jaw member to create the assembled coated end effector assembly. 
         [0053]    Turning now to  FIG. 6 , a method for manufacturing an HMDSO plasma coated end instrument is illustrated and will be described as method  600 . Method  600  begins in step  601  where a CrN coating is applied to at least a portion of an electrically conductive surface. The electrically conductive surface may be a sealing plate which may be formed of stainless steel. The stainless steel may be stamped from a large stainless steel sheet which has already been coated with any of the coatings described herein. Method  600  may optionally also include a step where an insulative layer is bonded or otherwise affixed to an underside of the electrically conductive surface. In some aspects, the insulative layer may be bonded to an entire sheet of stainless steel and the electrically conductive surface is stamped from the sheet of stainless steel after the insulative layer is bonded to the sheet of stainless steel. 
         [0054]    In step  603 , a treatment member is assembled. The treatment member may be a jaw member as previously described herein. Specifically, in step  603  the coated electrically conductive surface is affixed to a support base and/or an insulative housing. In  603 , the treatment member may be assembled via any suitable process including insert molding. In step  605 , an HMDSO plasma coating is applied to at least a portion of the electrically conductive surface and/or the assembled treatment member. Step  605  may be carried out via plasma coating the electrically conductive surface and/or the assembled treatment member. The HMDSO plasma coating may be enhanced by the addition of oxygen or fluorine in the plasma and deposition. Any or all of steps  601 - 605 , described above, may be repeated to assemble an opposing (second) treatment member. 
         [0055]    As described in more detail below with reference to the accompanying figures, another aspect of the present disclosure is directed to electrosurgical instruments having a HMDSO plasma coating disposed on at least a portion thereof, in combination with a portion of the instrument being coated with CrN and a portion of the instrument being coated with titanium nitride (“TiN”). As described above, the HMDSO plasma coating may be derived from HMDSO feed stock in plasma. For example, and without limitation, if pure argon is the media for the plasma and HMDSO is the feedstock, then the HMDSO plasma coating is polymeric with a structure close to [(CH3)2-Si—O]n. With increasing air content, a gradual change may be caused from organic polydimethylsiloxane-like coatings to inorganic, quartz-like deposits. For simplicity, the coating will be described herein as a HMDSO plasma coating. As described in further detail below, the coating may be further modified by introduction of other gasses or feedstocks. 
         [0056]    In one aspect, the present disclosure is directed to opposing jaw members of a vessel sealer instrument having sealing plates with a HMDSO plasma coating deposited over at least a portion of CrN coating, and the CrN coating deposited over at least a portion of a TiN coating. Having a non-stick HMDSO plasma coating disposed on an outer surface of the sealing plate, jaw member, end effector, and/or any other portion of a surgical instrument has many advantages. For instance, HMDSO plasma coating, used in conjunction with CrN coating and TiN coating operates to reduce the pitting of sealing plates as is common with electrosurgical arcing. The multiple layered coating provides durability against electrical and/or mechanical degradation of the sealing plates and the jaw members, as a whole, needed for long-term instrument durability. In particular, the additional HMDSO plasma coating in combination with a TiN and CrN coating reduces the sticking of tissue to the jaws or the surrounding insulating material of the end effector assembly and/or surgical instrument. 
         [0057]    Turning now to  FIGS. 8A-8B , aspects of an electrosurgical instrument including a multi-layered coating comprising any of HMDSO, CrN, or TiN will be described. Each of jaw members  310  and  320  includes an outer surface  311   a  and  311   b , respectively, that may include a respective TiN coating  400   c , CrN coating  400   a , and/or HMDSO plasma coating  400   b  disposed, or otherwise deposited, thereon. TiN coating  400   c , CrN coating  400   a , and/or HMDSO plasma coating  400   b  may be disposed on selective portions of either or both jaw members  310  and  320 , or may be disposed on the entire outer surfaces  311   a  and  311   b . In one embodiment, TiN coating  400   c , CrN coating  400   a , and HMDSO plasma coating  400   b  is disposed on an outer surface  317   a  and/or  317   b  of sealing plates  312  and  322 , respectively. As mentioned above, HMDSO plasma coating  400   b , used in conjunction with CrN coating  400   a  and TiN coating  400   c , operates to reduce the pitting of sealing plates  312  and  322  as is common with arcing. The triple coating provides durability against electrical and/or mechanical degradation of the sealing plates  312  and  322  and the jaw members  310  and  320  as a whole, which improves long-term instrument durability. In particular, the additional HMDSO plasma coating  400   b  over the CrN coating  400   a  and the TiN coating  400   c  reduces the sticking of tissue to the jaw members  310  and  320  or the surrounding insulating material. 
         [0058]    Support bases  319  and  329  are configured to support electrically conductive sealing plates  312  and  322  thereon. Sealing plates  312  and  322  may be affixed atop the support bases  319  and  329 , respectively, by any suitable method including but not limited to snap-fitting, overmolding, stamping, ultrasonic welding, etc. The support bases  319  and  329  and sealing plates  312  and  322  are at least partially encapsulated by insulative housings  316  and  326 , respectively, by way of an overmolding process to secure sealing plates  312  and  322  to support bases  319  and  329 , respectively. The sealing plates  312  and  322  are coupled to electrical jaw leads  325   a  and  325   b , respectively, via any suitable method (e.g., ultrasonic welding, crimping, soldering, etc.). Electrical jaw lead  325   a  supplies a first electrical potential to sealing plate  312  and electrical jaw lead  325   b  supplies a second electrical potential to opposing sealing plate  322 . 
         [0059]    Jaw member  320  (and/or jaw member  310 ) may also include a series of stop members  390  disposed on the inner facing surface  317   a  of sealing plate  312  to facilitate gripping and manipulation of tissue and 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. Some or all of the stop members  390  may be coated with the TiN coating  400   c , CrN coating  400   a , and/or the HMDSO plasma coating  400   b , or alternatively may be disposed on top of the TiN coating  400   c , CrN coating  400   a , and/or the HMDSO plasma coating  400   b . Further, the sealing plates  312  and  322  may include longitudinally-oriented knife slots  315   a  and  315   b , respectively, defined therethrough for reciprocation of a knife blade (not shown). The electrically insulative layers  330   a  and  330   b  disposed on the undersides  328   a  and  328   b , respectively, of sealing plates  312  and  322 , respectively, allow for various blade configurations such as, for example, T-shaped blades or I-shaped blades that may contact the underside of the sealing plate (and/or insulating layer) during reciprocation through knife slots  315   a ,  315   b . That is, the electrically insulative layers  330   a ,  330   b  operate to protect both the knife blade and the undersides  328   a  and  328   b  of the sealing plates  312  and  322 , respectively, from damage or wearing. Further, in the instance that an electrically conductive knife blade is utilized (e.g., for electric tissue cutting), the electrically insulative layers  330   a ,  330   b  help to electrically insulate the sealing plates  312 ,  322  from the electrically conductive knife blade. 
         [0060]    Turning now to  FIG. 7A , a front cross sectional view of sealing plate  312  is shown and will be described. Sealing plate  312  has a stainless steel layer  317 , an electrically insulative layer  330   a , a TiN coating  400   c , a CrN coating  400   a , and an HMDSO plasma coating  400   b . Sealing plate  312  may be formed by bonding electrically insulative layer  330   a  to the underside  328   b  of stainless steel layer  317 , coating at least the upper surface  317   a  of the stainless steel layer  317  with a TiN coating  400   c , coating at least a portion of the TiN coating  400   c  and/or the stainless steel layer  317  with a CrN coating  400   a , and coating at least a portion of the CrN coating  400   a  and/or the stainless steel layer  317  with an HMDSO plasma coating  400   b . Bonding electrically insulative layer  330   a  to stainless steel layer  317  may be accomplished by any suitable method including, but not limited to, applying adhesive between electrically insulative layer  330   a  and stainless steel layer  317 , using heat treatment to bond electrically insulative layer  330   a  to stainless steel layer  317 , and/or any combinations thereof. Electrically insulative layer  430   a  may have a thickness ranging from about 0.001 inches to about 0.005 inches. Sealing plate  312 , which includes stainless steel layer  317 , electrically insulative layer  330   a , TiN coating  400   c , CrN coating  400   a , and HMDSO plasma coating  400   b , may have a thickness ranging from about 0.005 inches to about 0.010 inches. 
         [0061]    Sealing plate  312  may be formed by bonding a sheet of electrically insulative material to a sheet of stainless steel and coating the sheet of stainless steel with at least one of a TiN coating, a CrN coating, and/or an HMDSO plasma coating. Once the materials are bonded together, and the stainless steel sheet is coated with one, two, or all three of the TiN layer, the CrN layer, and/or the HMDSO plasma layer, sealing plate  312  may be formed by stamping, machining, or any other suitable method used to form a sealing plate. 
         [0062]    Turning now to  FIG. 8B , a front cross sectional view of jaw member  310  is shown and will be described. Jaw member  310  includes sealing plate  312  having a stainless steel layer  317  and, optionally, an electrically insulative layer  330   a . Sealing plate  312  is affixed to support base  319  via any suitable process. Additionally, with sealing plate  312  secured to support base  319 , the combined sealing plate  312  and support base  319  is secured to insulative housing  316  via any suitable process. A TiN coating  400   c  and/or a CrN coating  400   a  is disposed over the outer surface  311   a  of the assembled sealing plate  312 , support base  319 , and insulative housing  316 . In one aspect, the TiN coating  400   c  is disposed over the stainless steel layer  317  and the CrN coating  400   a  is disposed over the outer surface  311   a  of the assembled sealing plate  312  (including the TiN coating  400   c ), support base  319 , and insulative housing  316 . In another aspect, the TiN coating  400   c  is disposed over the outer surface  311   a  of the assembled sealing plate  312 , support base  319 , and insulative housing  316  and the CrN coating  400   a  is disposed over a portion of, or all of, the TiN coating  400   c . Additionally, an HMDSO plasma coating  400   b  is disposed over the CrN coating  400   a . As described above, in embodiments it may be useful to coat only a partial outer surface  311   a  of the jaw member  310  or include thicker layers of the TiN coating  400   c , CrN coating  400   a , and/or the HMDSO plasma coating  400   b  on different portions of the outer surface  311   a  of the jaw member  310 . 
         [0063]    Additionally, or alternatively, in embodiments, the sealing plates  312  may be coated in the manner described above with respect to  FIG. 8A  and the outer surface  311   a  of the jaw member  310  may also be coated with the TiN coating  400   c , CrN coating  400   a , and/or the HMDSO plasma coating  400   b.    
         [0064]    Turning now to  FIG. 9 , a method for manufacturing an HMDSO plasma coated end effector assembly is illustrated and will be described as method  900 . Method  900  begins in step  901  where a TiN coating is applied to a sealing plate (for example, a stainless steel layer). Subsequent to coating the sealing plate with TiN (step  901 ), in step  903  a CrN coating and/or an HMDSO plasma coating is applied to a sealing plate over the TiN coating. Step  903  may include coating the entire TiN layer with CrN, or coating only a portion of the TiN layer with CrN. Additionally, step  903  may include depositing a CrN coating over portions of the sealing plate that have not been coated with TiN. 
         [0065]    Method  900  may optionally also include step  905  where an insulative layer is bonded or otherwise affixed to an underside of the sealing plate. In some aspects, the insulative layer may be bonded to an entire sheet of stainless steel and the sealing plate is stamped from the sheet of stainless steel after the insulative layer is bonded to the sheet of stainless steel. 
         [0066]    In step  907 , the jaw member is assembled. Specifically, in step  907  the coated sealing plate is affixed to a support base and/or an insulative housing. In  907 , the jaw member may be assembled via any suitable process including insert molding. In step  909 , an HMDSO plasma coating is applied to at least a portion of the assembled jaw member. Step  909  may be carried out via plasma coating in accordance with the methods described above. The HMDSO plasma coating may be enhanced by the addition of oxygen or fluorine in the plasma and deposition. Any or all of steps  901 - 909 , described above, are repeated to assemble an opposing (second) jaw member. In step  911 , the first assembled jaw member and the second assembled jaw member are assembled to form a coated end effector assembly. That is, the first assembled jaw member is pivotably coupled to the second assembled jaw member to create the assembled coated end effector assembly. 
         [0067]    Turning now to  FIG. 10 , a method for manufacturing an HMDSO plasma coated end instrument is illustrated and will be described as method  1000 . Method  1000  begins in step  1001  where a TiN coating is applied to at least a portion of an electrically conductive surface. The electrically conductive surface may be a sealing plate which may be formed of stainless steel. The stainless steel may be stamped from a large stainless steel sheet which has already been coated with any of the coatings described herein. Method  1000  may optionally also include a step where an insulative layer is bonded or otherwise affixed to an underside of the electrically conductive surface. In some aspects, the insulative layer may be bonded to an entire sheet of stainless steel and the electrically conductive surface is stamped from the sheet of stainless steel after the insulative layer is bonded to the sheet of stainless steel. 
         [0068]    In step  1003 , a CrN coating is applied over the TiN coating. As described above, step  1003  may include applying the CrN coating over portions of the electrically conductive surface that are not coated with the TiN coating. Alternatively, step  1003  may include applying the CrN coating over the entire TiN coating. 
         [0069]    In step  1005 , a treatment member is assembled. The treatment member may be a jaw member as previously described herein. Specifically, in step  1005  the coated electrically conductive surface is affixed to a support base and/or an insulative housing. In  1005 , the treatment member may be assembled via any suitable process including insert molding. In step  1007 , an HMDSO plasma coating is applied to at least a portion of the electrically conductive surface and/or the assembled treatment member. Step  1007  may be carried out via plasma coating the electrically conductive surface and/or the assembled treatment member. The HMDSO plasma coating may be enhanced by the addition of oxygen or fluorine in the plasma and deposition. Any or all of steps  1001 - 1007 , described above, may be repeated to assemble the opposing (second) treatment member. 
         [0070]    Although the above-described aspects are directed to CrN, TiN, and HMDSO coatings, it is appreciated that any nitride physical vapor deposition coating may be utilized in place of the CrN coating and/or the TiN coating. For example, other coatings that may be used in place of the CrN coating and/or the TiN coating may include TiAlCN, TiZrN, CrAlN, CrAlCN, AlCrN, multilayer designs, nanolayered coatings, nanocomposite coatings, diamond-like coatings, or any combinations thereof. Additionally, although  FIGS. 8A, 8B, 9, and 10  are described as including a CrN coating over a TiN coating, it is appreciated that the TiN coating may be replaced with a CrN coating or any other coating. 
         [0071]    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.