US20110270251A1 - Insulated Sealing Plate - Google Patents

Abstract

An end effector assembly for use with an electrosurgical instrument is provided. The end effector assembly has a pair of opposing jaw members. Each of the jaw members has a support base, an electrical jaw lead, and a sealing plate coupled to the electrical jaw lead. The sealing plate has a stainless steel layer and an electrically insulative layer.

Description

BACKGROUND
• 1. Technical Field
• 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 electrical insulation.
• 2. Background of the Related Art
• 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.
• 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.
SUMMARY
• In an embodiment of the present disclosure, an end effector assembly including a pair of opposing jaw members is provided. Each of the jaw members includes a support base, an electrical jaw lead, and a sealing plate coupled to the electrical jaw lead. The sealing plate has a stainless steel layer and an electrically insulative layer bonded to an underside of the sealing plate.
• In another embodiment of the present disclosure, an electrosurgical instrument for sealing tissue is provided. The electrosurgical instrument may include a housing having at least one shaft extending therefrom, a handle assembly operably coupled to the housing and including at least one movable handle, a rotating assembly operably coupled to the housing and configured to rotate the at least one shaft, and an end effector assembly including a pair of opposing jaw members. Each of the jaw members includes a support base, an electrical jaw lead, and a sealing plate coupled to the electrical jaw lead. The sealing plate has a stainless steel layer and a polyimide layer bonded to an underside of the sealing plate.
• In another embodiment of the present disclosure, a method of manufacturing a jaw member of an electrosurgical end effector assembly includes the steps of providing a support base and bonding a polyimide layer to an underside of a stainless steel tissue sealing surface. The method also includes the steps of engaging the underside of the tissue sealing surface to the support base and coupling an electrical lead to the tissue sealing surface, The electrical lead is adapted to connect the tissue sealing surface to an energy source. The method also includes the step of overmolding an insulative material about the support base to secure the tissue sealing surface to the support base.
• In another embodiment of the present disclosure, a method of manufacturing a sealing plate for a jaw member of an electrosurgical forceps includes the steps of bonding a sheet of polyimide to a sheet of stainless steel and stamping the bonded sheet to form a sealing plate for affixing to a jaw member of an electrosurgical forceps.
BRIEF DESCRIPTION OF THE DRAWINGS
• 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:
• FIG. 1 is a perspective view of an endoscopic bipolar forceps in accordance with an embodiment of the present disclosure;
• FIG. 2 is a perspective view of an open bipolar forceps according to an embodiment of the present disclosure;
• FIGS. 3A and 3B are exploded views of opposing jaw members according to an embodiment of the present disclosure; and
• FIG. 4 is a cross sectional view of a sealing plate according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
• 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 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.
• 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 embodiments described herein.
• As described in more detail below with reference to the accompanying figures, the present disclosure is directed to opposing jaw members of a vessel sealer having sealing plates with a bonded electrically insulative bottom layer on an underside thereof. Having a electrically insulative layer between the sealing plate and the jaw member has many advantages. For instance, the need for the above discussed pre-shot overmolding of insulative material about the jaw members is eliminated, thereby simplifying the manufacturing of the vessel sealer. Additionally, bonding a electrically insulative layer to the sealing plate strengthens the structure thereof, thereby allowing for larger or longer sealing plates and/or jaw members to be manufactured without necessarily compromising structural integrity.
• Turning now toFIG. 1, an instrument generally identified asforceps10 is for use with various surgical procedures and includes ahousing20, ahandle assembly30, arotating assembly80, atrigger assembly70, and anend effector assembly100 that mutually cooperate to grasp, seal, and divide tubular vessels and vascular tissues.Forceps10 includes ashaft12 that has adistal end16 dimensioned to mechanically engage theend effector assembly100 and aproximal end14 that mechanically engages thehousing20. Theend effector assembly100 includes opposingjaw members110 and120, which cooperate to effectively grasp tissue for sealing purposes. Theend effector assembly100 is a bilateral assembly, i.e., bothjaw members110 and120 pivot relative to one another about a pivot pin (not shown). Thejaw members110 and120 may be curved to facilitate manipulation of tissue and to provide better “line-of-sight” for accessing targeted tissues.
• 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”.
• With regard toFIG. 2, anopen forceps200 for use with various surgical procedures is shown.Forceps200 includes a pair ofopposing shafts212aand212bhaving an end effector assembly230 attached to thedistal ends216aand216bthereof, respectively. End effector assembly230 includes pair ofopposing jaw members232 and234 that are pivotably connected about apivot pin265 and that are movable relative to one another to grasp tissue. Eachshaft212aand212bincludes ahandle215 and217, respectively, disposed at theproximal end214aand214bthereof and that each define afinger hole215aand217a,respectively, therethrough for receiving a finger of the user.Finger holes215aand217afacilitate movement of theshafts212aand212brelative to one another to pivot thejaw members232 and234 from an open position, wherein thejaw members232 and234 are disposed in spaced relation relative to one another, to a clamping or closed position, wherein thejaw members232 and234 cooperate to grasp tissue therebetween.
• FIGS. 3A and 3B are perspective views of opposingjaw members310 and320 according to one embodiment of the present disclosure. Similar tojaw members232 and234, each of thejaw members310 and320 include:sealing plates312 and322, respectively; electrical jaw leads325aand325b,respectively; andsupport bases319 and329 that extend distally fromflanges313 and323, respectively. Each ofsealing plates312 and322 include anunderside328aand328b,respectively, that has a respective electricallyinsulative layer330aand330bbonded thereto. Electricallyinsulative layers330aand330boperate to electrically insulatesealing plates312 and322, respectively, fromsupport bases319 and329, respectively. Further, electricallyinsulative layers330aand330boperate to prevent or slow the onset of corrosion ofsealing plates312 and322, respectively, at least on theundersides328a,328bthereof. In one embodiment, electricallyinsulative layers330aand330bmay be formed from polyimide. However, in other embodiments, any suitable electrically insulative material may be utilized, such as polycarbonate, polyethylene, etc.
• Support bases319 and329 are configured to support electricallyconductive sealing plates312 and322 thereon.Sealing plates312 and322 may be affixed atop the support bases319 and329, respectively, by any suitable method including but not limited to snap-fitting, overmolding, stamping, ultrasonic welding, etc. The support bases319 and329 and sealingplates312 and322 are at least partially encapsulated byinsulative housings316 and326, respectively, by way of an overmolding process to secure sealingplates312 and322 to supportbases319 and329, respectively. The sealingplates312 and322 are coupled to electrical jaw leads325aand325b,respectively, via any suitable method (e.g., ultrasonic welding, crimping, soldering, etc.). Electrical jaw lead325asupplies a first electrical potential to sealingplate312 andelectrical jaw lead325bsupplies a second electrical potential to opposing sealingplate322.
• Jaw member320 may also include a series ofstop members390 disposed on the inner facing surface of sealingplate312 to facilitate gripping and manipulation of tissue and to define a gap between opposingjaw members310 and320 during sealing and cutting of tissue. The series ofstop members390 are applied onto the sealingplate312 during manufacturing. Further, the sealingplates312 and322 may include longitudinally-orientedknife slots315aand315b,respectively, defined therethrough for reciprocation of a knife blade (not shown). The electricallyinsulative layers330aand330bdisposed on theundersides328aand328b,respectively, of sealingplates312 and322, respectively, allow for various blade configurations such as, for example, t-shaped blades that may contact the underside of the sealing plate during reciprocation throughknife slots315a,315b.That is, the electricallyinsulative layers330a,330boperate to protect both the knife blade and theundersides328aand328bof the sealingplates312 and322, respectively, from damage or wearing. Further, in the instance that an electrically conductive knife blade is utilized (e.g., for electric tissue cutting), the electricallyinsulative layers330a,330bhelp to electrically insulate the sealingplates312,322 from the electrically conductive knife blade.
• Turning now toFIG. 4, a cross-sectional view of sealingplate412 is shown.Sealing plate412 is similar to sealingplates312 and322 described above. As shown inFIG. 4, sealingplate412 has astainless steel layer410 and a electricallyinsulative layer430a.Sealing plate500 may be formed by bonding electricallyinsulative layer430atostainless steel layer410. Bonding electricallyinsulative layer430atostainless steel layer410 may be accomplished by any suitable method including, but not limited to, applying adhesive between electricallyinsulative layer430aandstainless steel layer410, using heat treatment to bond electricallyinsulative layer430atostainless steel layer410.Electrically insulative layer430amay have a thickness ranging from about 0.001 inches to about 0.005 inches.Sealing plate412, which includesstainless steel layer410 and electricallyinsulative layer430a,may have a thickness ranging from about 0.005 inches to about 0.010 inches.Sealing plate412 may be formed by bonding a sheet of electrically insulative to a sheet of stainless steel. Once the two materials are bonded together, sealingplate412 may be formed by stamping, machining, or any other suitable method used to form a sealing plate.
• 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 drawing figs. 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.

Claims (18)

1. An end effector assembly including a pair of opposing jaw members, each of the jaw members comprising:

a support base;

an electrical jaw lead; and

a sealing plate coupled to the electrical jaw lead, the sealing plate having a stainless steel layer and an electrically insulative layer bonded to an underside of the sealing plate.

2. The end effector assembly according toclaim 1, wherein the electrically insulative layer is formed from polyimide.

3. The end effector assembly according toclaim 1, wherein the electrically insulative layer is formed from a material selected from the group consisting of polycarbonate and polyethylene.

4. The end effector assembly according toclaim 1, wherein the electrical jaw lead is ultrasonically welded to the stainless steel layer of the sealing plate.

5. The end effector assembly according toclaim 1, wherein the electrically insulative layer is bonded to the stainless steel layer by adhesive.

6. The end effector assembly according toclaim 1, wherein the electrically insulative layer is bonded to the stainless steel layer via heat treatment.

7. An electrosurgical instrument for sealing tissue, comprising:

a housing having at least one shaft extending therefrom;

a handle assembly operably coupled to the housing and including at least one movable handle;

a rotating assembly operably coupled to the housing and configured to rotate the at least one shaft; and

an end effector assembly including a pair of opposing jaw members, each of the jaw members comprising:

a support base;

an electrical jaw lead; and

a sealing plate coupled to the electrical jaw lead, the sealing plate having a stainless steel layer and an electrically insulative layer bonded to an underside of the sealing plate.

8. The electrosurgical instrument according toclaim 7, wherein the pair of opposing jaw members each include a knife channel defined longitudinally therethrough.

9. The electrosurgical instrument according toclaim 7, wherein the electrical jaw lead is coupled to the sealing plate with an ultrasonic weld.

10. The electrosurgical instrument according toclaim 7, wherein the electrical jaw lead is ultrasonically welded to the stainless steel layer of the sealing plate.

11. The electrosurgical instrument according toclaim 7, wherein the electrically insulative layer is bonded to the stainless steel layer.

12. The electrosurgical instrument according toclaim 7, wherein the electrically insulative layer is bonded to the stainless steel layer by adhesive.

13. The end effector assembly according toclaim 7, wherein the electrically insulative layer is bonded to the stainless steel layer via heat treatment.

14. A method of manufacturing a jaw member of an electrosurgical end effector assembly, the steps comprising:

providing a support base;

bonding an electrically insulative layer to an underside of a stainless steel tissue sealing surface;

coupling an electrical lead to the tissue sealing surface, the electrical lead adapted to connect the tissue sealing surface to an energy source;

engaging the underside of the tissue sealing surface to the support base; and

overmolding an insulative material about the support base to secure the tissue sealing surface thereto.

15. A method according toclaim 14, wherein the support base is formed from machined steel.

16. A method according toclaim 14, wherein the insulative material is an insulative plastic material.

17. A method according toclaim 14, wherein the bonding step further comprises the step of applying adhesive to the underside of the tissue sealing surface,

18. A method according toclaim 14, wherein the electrically insulative layer is formed from polyimide.

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