WO2023187737A1

WO2023187737A1 - Thermal cutting assembly for mechanical engagement within jaw member

Info

Publication number: WO2023187737A1
Application number: PCT/IB2023/053247
Authority: WO
Inventors: James D. Allen Iv; Kenneth E. NETZEL
Original assignee: Covidien Lp
Priority date: 2022-03-31
Filing date: 2023-03-31
Publication date: 2023-10-05

Abstract

A thermal cutting assembly for a jaw member of a surgical instrument includes an elongated substrate including proximal and distal ends and a cutting edge disposed along an upper surface thereof. A dielectric insulator is disposed along one side of the substrate and extends therealong from the proximal to the distal end thereof. A resistive element is connected to an energy source and is disposed in thermal communication with the substrate, the resistive element is configured to extend along the dielectric insulator to a distal end portion thereof. An encapsulant is disposed atop both the dielectric insulator and the resistive element. The distal end of the substrate includes a mechanical interface configured to engage a portion of a jaw member to secure the substrate therein.

Description

THERMAL CUTTING ASSEMBLY FOR MECHANICAL ENGAGEMENT WITHIN JAW MEMBER

FIELD

[0001] The present disclosure relates to surgical instruments and, more particularly, to electrosurgical instruments for sealing and cutting tissue utilizing a thermal cutting element.

BACKGROUND

[0002] A surgical forceps is a pliers-like instrument that relies on mechanical action between its jaw members to grasp, clamp, and constrict tissue. Electrosurgical forceps utilize both mechanical clamping action and energy to heat tissue to treat, e.g., coagulate, cauterize, or seal, tissue. Typically, once tissue is treated, the surgeon has to accurately sever the treated tissue. Accordingly, many electrosurgical forceps are designed to incorporate a knife that is advanced between the jaw members to cut the treated tissue. As an alternative to a mechanical knife, an energy-based tissue cutting element or thermal cutting element may be provided to cut the treated tissue using energy, e.g., thermal, electrosurgical, ultrasonic, light, or other suitable energy.

SUMMARY

[0003] 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. Further, to the extent consistent, any or all of the aspects detailed herein may be used in conjunction with any or all of the other aspects detailed herein.

[0004] Provided in accordance with aspects of the present disclosure is a thermal cutting assembly for a jaw member of a surgical instrument which includes an elongated substrate including proximal and distal ends and a cutting edge disposed along an upper surface thereof. A dielectric insulator is disposed along one or both sides of the substrate and extends partially or fully therealong from the proximal to the distal end thereof. One or more resistive elements are adapted to connect to an energy source and are disposed in thermal communication with the substrate, the one or more resistive elements are configured to extend along the dielectric insulator to a distal end portion thereof. An encapsulant is disposed atop both the dielectric insulator and the one or more resistive elements, wherein the distal end (or other portion) of the substrate includes one or more mechanical interfaces configured to engage a portion of a jaw member to secure the substrate therein.

[0005] In aspects in accordance with the present disclosure, the one or more resistive elements includes one or more traces composed of aluminum, copper, silver, chromium, titanium, stainless steel, nickel, chrome, tin, platinum, palladium, gold, nichrome, and a ferritic iron-chromium-aluminum alloy. In other aspects in accordance with the present disclosure, the one or more traces are layered atop the dielectric insulator. In still other aspects in accordance with the present disclosure, the one or more resistive elements includes two or more traces layered atop one another.

[0006] In aspects in accordance with the present disclosure, the one or more mechanical interfaces includes a hook disposed at the distal end of the substrate, the hook defining a notch configured to operably engage the portion of the jaw member.

[0007] In aspects in accordance with the present disclosure, the substrate includes two or more mechanical interfaces configured to engage different portions of the jaw member to secure the substrate therein. In other aspects in accordance with the present disclosure, a first of the two or more mechanical interfaces includes a hook disposed at the distal end of the substrate, the hook defining a notch configured to operably engage a first portion of the jaw member and a second of the two or more mechanical interfaces includes a tab disposed at a proximal portion of the substrate, the tab configured to engage a second portion of the jaw member. In still other aspects in accordance with the present disclosure, the hook is configured to engage the first portion of the jaw member in an angular manner to seat the first portion of the jaw member within the notch. In yet other aspects in accordance with the present disclosure, the tab is configured to operably engage the second portion of the jaw member after engagement of the first portion of the jaw member within the notch and proximal movement of the substrate relative to the first portion of the jaw member.

[0008] In aspects in accordance with the present disclosure, the substrate includes one or more second mechanical interfaces configured to engage a shaft of the surgical instrument when operably coupled to the jaw member to secure the thermal cutting assembly within the jaw member.

[0009] Provided in accordance with aspects of the present disclosure is a thermal cutting assembly for a jaw member of a surgical instrument which includes an elongated substrate including proximal and distal ends and a cutting edge disposed along an upper surface thereof. A dielectric insulator is disposed along one or both sides of the substrate and extends partially or fully therealong from the proximal to the distal end thereof. A first, electrically conductive trace is adapted to connect at one end to an energy source and is disposed in electrical communication with a first end of one or more resistive traces, a second end of the resistive trace(s) is connected to a second, electrically conductive trace adapted to connect at an opposite end to the energy source, the resistive trace(s) layered atop the dielectric insulator and extending therealong to a distal end portion thereof. An encapsulant is disposed atop the dielectric insulator, the first and second electrically conductive traces, and the resistive trace(s), wherein at least the distal end of the substrate includes one or more mechanical interfaces configured to engage a portion of a jaw member to secure the substrate therein.

[0010] In aspects in accordance with the present disclosure, the electrically conductive traces and the resistive trace(s) include one or more of aluminum, copper, silver, chromium, titanium, stainless steel, nickel, chrome, tin, platinum, palladium, gold, nichrome, and a ferritic iron- chromium-aluminum alloy.

[0011] In aspects in accordance with the present disclosure, the one or more mechanical interface includes a hook disposed at the distal end of the substrate, the hook defining a notch configured to operably engage the portion of the jaw member.

[0012] In aspects in accordance with the present disclosure, the substrate includes two or more mechanical interfaces configured to engage different portions of the jaw member to secure the substrate therein. In other aspects in accordance with the present disclosure, a first of the two or more mechanical interfaces includes a hook disposed at the distal end of the substrate, the hook defining a notch configured to operably engage a first portion of the jaw member and a second of the two or more mechanical interfaces includes a tab disposed at a proximal portion of the substrate, the tab configured to engage a second portion of the jaw member. In yet other aspects in accordance with the present disclosure, the hook is configured to engage the first portion of the jaw member in an angular manner to seat the first portion of the jaw member within the notch. In still other aspects in accordance with the present disclosure, the tab is configured to operably engage the second portion of the jaw member after engagement of the first portion of the jaw member within the notch and proximal movement of the substrate relative to the first portion of the jaw member. [0013] Provided in accordance with aspects of the present disclosure is a method of manufacturing a thermal cutting assembly of a jaw member of a surgical instrument which includes: disposing a dielectric insulator on one or both side of an elongated substrate having one or more mechanical interfaces operatively associated therewith configured to engage a portion of a jaw member; disposing one or more resistive elements adapted to connect to an energy source and disposed in thermal communication with the substrate along the dielectric insulator; encapsulating the dielectric insulator and the one or more resistive elements to form a thermal cutting assembly; and seating the thermal cutting assembly within the jaw member and engaging the one or more mechanical interfaces of the substrate with the portion of the jaw member.

[0014] In aspects in accordance with the present disclosure, seating the thermal cutting assembly includes: engaging a hook disposed at the distal end of the substrate with a first portion of the jaw member such that the first portion seats within a notch defined within the hook; and engaging a tab disposed at a proximal portion of the substrate with a second portion of the jaw member. In other aspects in accordance with the present disclosure, the hook engages the first portion of the jaw member in an angular manner. In yet other aspects in accordance with the present disclosure, the tab engages the second portion of the jaw member after engagement of the first portion of the jaw member within the notch and proximal movement of the substrate relative to the first portion of the jaw member.

BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and other aspects and features of the present disclosure will become more apparent in view of the following detailed description when taken in conjunction with the accompanying drawings wherein like reference numerals identify similar or identical elements.

[0016] FIG. 1 is a perspective view of a shaft-based electrosurgical forceps provided in accordance with the present disclosure shown connected to an electrosurgical generator;

[0017] FIG. 2 is a perspective view of a hemostat-style electrosurgical forceps provided in accordance with the present disclosure;

[0018] FIG. 3 is a schematic illustration of a robotic surgical instrument provided in accordance with the present disclosure; [0019] FIG. 4 is a perspective view of a distal end portion of the forceps of FIG. 1, wherein first and second jaw members of an end effector assembly of the forceps are disposed in a spaced-apart position exposing a thermal cutter assembly;

[0020] FIG. 5 is a perspective view of a distal end portion of the forceps of FIG. 1, wherein first and second jaw members of the end effector assembly of the forceps are disposed in a spaced-apart position and the thermal cutter assembly is separated therefrom exposing a slot defined in one of the jaw members;

[0021] FIG. 6A is a schematic view of the thermal cutter assembly in accordance with the present disclosure;

[0022] FIG. 6B is a schematic side view of the thermal cutter assembly in accordance with the present disclosure;

[0023] FIG. 7A is a side view of a substrate of a thermal cutting assembly having first and second mechanical interfaces for engaging a jaw member;

[0024] FIG. 7B is an enlarged, front perspective view of the thermal cutting assembly of FIG. 7A showing assembly of a dielectric insulator and a resistive element or trace disposed on a side thereof;

[0025] FIG. 7C is an enlarged, front perspective view of the thermal cutting assembly showing an encapsulant layered atop the dielectric insulator and the resistive element;

[0026] FIG. 8A is a side perspective view of the thermal cutting assembly showing the second mechanical interface depending therefrom; and

[0027] FIG. 8B is an enlarged, front perspective view of the thermal cutting assembly being seated within a jaw member with the first and second mechanical interfaces poised for engagement therewith.

DETAILED DESCRIPTION

[0028] Referring to FIG. 1, a shaft-based electrosurgical forceps provided in accordance with the present disclosure is shown generally identified by reference numeral 10. Aspects and features of forceps 10 not germane to the understanding of the present disclosure are omitted to avoid obscuring the aspects and features of the present disclosure in unnecessary detail.

[0029] Forceps 10 includes a housing 20, a handle assembly 30, a rotating assembly 70, a first activation switch 80, a second activation switch 90, and an end effector assembly 100. As shown, end effector assembly 100 includes jaw members 110 and 120 configured for unilateral movement relative to one another. Bilateral movement of the jaw members 110, 120 is also envisioned. Forceps 10 further includes a shaft 12 having a distal end portion 14 configured to (directly or indirectly) engage end effector assembly 100 and a proximal end portion 16 that (directly or indirectly) engages housing 20. Forceps 10 also includes cable “C” that connects forceps 10 to an energy source, e.g., an electrosurgical generator “G” Cable “C” includes a wire (or wires) (not shown) extending therethrough that has sufficient length to extend through shaft 12 in order to connect to one or both tissue-treating surfaces 114, 124 of jaw members 110, 120, respectively, of end effector assembly 100 (see FIG. 4) to provide energy thereto.

[0030] First activation switch 80 is coupled to tissue-treating surfaces 114, 124 (FIG. 4) and the electrosurgical generator “G” for enabling the selective activation of the supply of energy to jaw members 110, 120 for treating, e.g., cauterizing, coagulating/ desiccating, and/or sealing, tissue. Second activation switch (e.g., thumb switch 90) is coupled to thermal cutter assembly 130 of jaw member 120 (FIG. 4) and the electrosurgical generator “G” for enabling the selective activation of the supply of energy to thermal cutter assembly 130 for thermally cutting tissue. Second activation switch 90 may be actuated via any finger, in-line with handle, footswitch, etc.

[0031] Alternatively, a single activation switch may be utilized wherein the generator “G” sequentially seals and then cuts with a single actuation of the switch, e.g., switch 80. A “seal” may be indicated by an audible tone from the generator “G” and after a short or programmable delay the forceps 10 (or the generator algorithm) transitions into a cut cycle or cut “mode”. Again a “cut” may be represented by a different tone from the generator “G” or from the forceps 10.

[0032] Handle assembly 30 of forceps 10 includes a fixed handle 50 and a movable handle 40. Fixed handle 50 is integrally associated with housing 20 and handle 40 is movable relative to fixed handle 50. Movable handle 40 of handle assembly 30 is operably coupled to a drive assembly (not shown) that, together, mechanically cooperate to impart movement of one or both of jaw members 110, 120 of end effector assembly 100 about a pivot 103 between a spaced-apart position and an approximated position to grasp tissue between tissue-treating surfaces 114, 124 of jaw members 110, 120. As shown in FIG. 1, movable handle 40 is initially spaced-apart from fixed handle 50 and, correspondingly, jaw members 110, 120 of end effector assembly 100 are disposed in the spaced-apart position. Movable handle 40 is depressible from this initial position to a depressed position corresponding to the approximated position of jaw members 110, 120. Rotating assembly 70 includes a rotation wheel 72 that is selectively rotatable in either direction to correspondingly rotate end effector assembly 100 relative to housing 20.

[0033] Referring to FIG. 2, a hemostat-style electrosurgical forceps provided in accordance with the present disclosure is shown generally identified by reference numeral 210. Aspects and features of forceps 210 not germane to the understanding of the present disclosure are omitted to avoid obscuring the aspects and features of the present disclosure in unnecessary detail.

[0034] Forceps 210 includes two elongated shaft members 212a, 212b, each having a proximal end portion 216a, 216b, and a distal end portion 214a, 214b, respectively. Forceps 210 is configured for use with an end effector assembly 100’ similar to end effector assembly 100 (FIG. 4). More specifically, end effector assembly 100’ includes first and second jaw members 110’, 120’ attached to respective distal end portions 214a, 214b of shaft members 212a, 212b. Jaw members 110’, 120’ are pivotably connected about a pivot 103’. Each shaft member 212a, 212b includes a handle 217a, 217b disposed at the proximal end portion 216a, 216b thereof. Each handle 217a, 217b defines a finger hole 218a, 218b therethrough for receiving a finger of the user. As can be appreciated, finger holes 218a, 218b facilitate movement of the shaft members 212a, 212b relative to one another to, in turn, pivot jaw members 110’, 120’ from the spaced-apart position, wherein jaw members 110’, 120’ are disposed in spaced relation relative to one another, to the approximated position, wherein jaw members 110’, 120’ cooperate to grasp tissue therebetween.

[0035] One of the shaft members 212a, 212b of forceps 210, e.g., shaft member 212b, includes a proximal shaft connector 219 configured to connect forceps 210 to a source of energy, e.g., electrosurgical generator “G” (FIG.l). Proximal shaft connector 219 secures a cable “C” to forceps 210 such that the user may selectively supply energy to jaw members 110’, 120’ for treating tissue. More specifically, a first activation switch 280 (similar to activation switch 80 discussed above) is provided for supplying energy to jaw members 110’, 120’ to treat tissue upon sufficient approximation of shaft members 212a, 212b, e.g., upon activation of first activation switch 280 via shaft member 212a. A second activation switch 290 (similar to second activation switch 90 discussed above) disposed on either or both of shaft members 212a, 212b is coupled to the thermal cutter element (not shown, similar to thermal cutter assembly 130 of jaw member 120 (FIG. 4)) of one of the jaw members 110’, 120’ of end effector assembly 100’ and to the electrosurgical generator “G” for enabling the selective activation of the supply of energy to the thermal cutter assembly 130 for thermally cutting tissue.

[0036] Alternatively, a single activation switch may be utilized wherein the generator “G” sequentially seals and then cuts with a single actuation of the switch, e.g., switch 280. A “seal” may be indicated by an audible tone from the generator “G” and after a short or programmable delay the forceps 210 (or the generator algorithm) transitions into a cut cycle or cut “mode”. Again a “cut” may be represented by a different tone from the generator “G” or from the forceps 210.

[0037] Jaw members 110’, 120’ define a curved configuration wherein each jaw member is similarly curved laterally relative to a longitudinal axis of end effector assembly 100’. However, other suitable curved configurations including curvature towards one of the jaw members 110, 120’ (and thus away from the other), multiple curves with the same plane, and/or multiple curves within different planes are also contemplated. Jaw members 110, 120 of end effector assembly 100 (FIG. 1) may likewise be curved according to any of the configurations noted above or in any other suitable manner.

[0038] Referring to FIG. 3, a robotic surgical instrument provided in accordance with the present disclosure is shown generally identified by reference numeral 1000. Aspects and features of robotic surgical instrument 1000 not germane to the understanding of the present disclosure are omitted to avoid obscuring the aspects and features of the present disclosure in unnecessary detail.

[0039] Robotic surgical instrument 1000 includes a plurality of robot arms 1002, 1003; a control device 1004; and an operating console 1005 coupled with control device 1004. Operating console 1005 may include a display device 1006, which may be set up in particular to display three-dimensional images; and manual input devices 1007, 1008, by means of which a surgeon may be able to telemanipulate robot arms 1002, 1003 in a first operating mode. Robotic surgical instrument 1000 may be configured for use on a patient 1013 lying on a patient table 1012 to be treated in a minimally invasive manner. Robotic surgical instrument 1000 may further include a database 1014, in particular coupled to control device 1004, in which are stored, for example, pre-operative data from patient 1013 and/or anatomical atlases.

[0040] Each of the robot arms 1002, 1003 may include a plurality of members, which are connected through joints, and an attaching device 1009, 1011, to which may be attached, for example, an end effector assembly 1100, 1200, respectively. End effector assembly 1100 is similar to end effector assembly 100 (FIG. 4), although other suitable end effector assemblies for coupling to attaching device 1009 are also contemplated. End effector assembly 1200 may be any end effector assembly, e.g., an endoscopic camera, other surgical tool, etc. Robot arms 1002, 1003 and end effector assemblies 1100, 1200 may be driven by electric drives, e.g., motors, that are connected to control device 1004. Control device 1004 (e.g., a computer) may be configured to activate the motors, in particular by means of a computer program, in such a way that robot arms 1002, 1003, their attaching devices 1009, 1011, and end effector assemblies 1100, 1200 execute a desired movement and/or function according to a corresponding input from manual input devices 1007, 1008, respectively. Control device 1004 may also be configured in such a way that it regulates the movement of robot arms 1002, 1003 and/or of the motors.

[0041] Turning to FIGS. 4-5, end effector assembly 100, as noted above, includes first and second jaw members 110, 120. Each jaw member 110, 120 may include a structural frame 111, 121, a jaw housing 112, 122, and a tissue-treating plate 113, 123 defining the respective tissuetreating surface 114, 124 thereof. Alternatively, only one of the jaw members, e.g., jaw member 120, may include structural frame 121, jaw housing 122, and tissue-treating plate 123 defining the tissue-treating surface 124. In such embodiments, the other jaw member, e.g., jaw member 110, may be formed as a single unitary body, e.g., a piece of conductive material acting as the structural frame 111 and jaw housing 112 and defining the tissue- treating surface 114.

[0042] An outer surface of the jaw housing 112, in such embodiments, may be at least partially coated with an electrically insulative material or may remain exposed. In embodiments, tissue-treating plates 113, 123 may be deposited onto jaw housings 112, 122 or jaw inserts (not shown) disposed within jaw housings 112, 122, e.g., via sputtering. Alternatively, tissue-treating plates 113, 123 may be pre-formed and engaged with jaw housings 112, 122 and/or jaw inserts (not shown) disposed within jaw housings 112, 122 via, for example, overmolding, adhesion, mechanical engagement, etc. Other methods of depositing the tissue- treating plates 113, 123 onto the jaw inserts are described in detail below.

[0043] Referring in particular to FIGS. 4 and 5, jaw member 110, as noted above, may be configured similarly as jaw member 120, may be formed as a single unitary body, or may be formed in any other suitable manner so as to define a structural frame 111 and a tissue-treating surface 114 opposing tissue-treating surface 124 of jaw member 120. Structural frame 111 includes a proximal flange portion 116 about which jaw member 110 is pivotably coupled to jaw member 120. In shaft-based or robotic embodiments, proximal flange portion 116 receives pivot 103 and which mounts atop flange 126 of jaw member 120 (FIG. 4) such that actuation of movable handle 40 (FIG. 1) or a robotic drive, pivots jaw member 110 about pivot 103 and relative to jaw member 120 between the spaced-apart position and the approximated position. However, other suitable drive arrangements are also contemplated, e.g., using cam pins and cam slots, a screw-drive mechanism, etc.

[0044] For the purposes of further describing one or both of the jaw members 110, 120 (and 210, 220), each jaw member 110, 120 may include a longitudinally-extending insulative member 115 defined within a slot 125 extending along at least a portion of the length of tissue-treating surfaces 114, 124 (FIG. 5). Insulative member 115 may be transversely centered on either or both tissue- treating surfaces 114, 124 or may be offset relative thereto. As explained in more detail below with respect to jaw member 120, insulative member 115 may house and electrically and/or thermally isolate the thermal cutter assembly 130 separately activatable to cut tissue upon activation thereof. Further, insulative member 115 may be disposed, e.g., deposited, coated, etc., on tissue- treating surface 114, 124, may be positioned within the channel or recess defined within tissue-treating surface 114, 124, or may define any other suitable configuration.

[0045] Additionally, insulative member 115 may be substantially (within manufacturing, material, and/or use tolerances) coplanar with each respective tissue-treating surface 114, 124 may protrude from each respective tissue- treating surface 114, 124, may be recessed relative to each respective tissue-treating surface 114, 124 or may include different portions that are coplanar, protruding, and/or recessed relative to tissue-treating surfaces 114, 124. Moreover, insulative member 115 and thermal cutter assembly 130 may be curvilinear to follow the configuration of the jaw members 110, 120. Insulative member 115 may be formed from, for example, ceramic, parylene, glass, nylon, PTFE, or other suitable material(s) (including combinations of insulative and non-insulative materials).

[0046] With reference to FIGS. 4 and 5, as noted above, jaw member 120 includes a structural frame 121, a jaw housing 122, and a tissue-treating plate 123 defining the tissuetreating surface 124 thereof. With reference also to FIG. 6A, details relating to the thermal cutter assembly 130 are generally defined to include the following elements (described internally to externally): substrate 131 or other internalized bendable metal structure that is both thermally and electrically conductive, e.g., stainless steel, aluminum, etc.; insulator 132 having generally electrically insulative properties and at least partially thermally conductive, e.g., sintered glass, alumina, plasma electrolytic oxidation (PEO anodize), Silica, etc.; resistive element 133 or any metal that is resistive but certain metals may have better thermal coefficients than others; and encapsulant 134 or an electrically insulative materials that is at least partially thermally conductive (may be the same or similar to the insulator). As explained below, the resistive element 133 may be deposited atop insulator 132 via sputtering or the like.

[0047] FIG. 6B shows a side view of thermal cutter assembly 130 and the electrical connections associated therewith. Generally, electrically conductive pads 135a, 135b connect to opposite ends 133a, 133b of resistive element 133 via traces 133al, 133bl which are electrically conductive traces (low resistance / low heat). As explained in detail below, resistive element 133 is configured to rapidly generate heat due to high resistive properties when electrical current is passed therethrough.

[0048] Structural frame 121 defines a proximal flange portion 126 and a distal body portion (not shown) extending distally from proximal flange portion 126. Proximal flange portion 126 is bifurcated to define a pair of spaced-apart proximal flange portion segments that receive proximal flange 111 of jaw member 110 therebetween and define aligned apertures 127 configured for receipt of pivot 103 therethrough/thereon to pivotably couple jaw members 110, 120 with one another (FIG. 5).

[0049] Jaw housing 122 of jaw member 120 is disposed about the distal body portion of structural frame 121, e.g., via overmolding, adhesion, mechanical engagement, etc., and supports tissue- treating plate 123 thereon, e.g., via overmolding, adhesion, mechanical engagement, depositing (such as, for example, via sputtering or thermal spraying), etc. Tissue-treating plate 123, as noted above, defines tissue- treating surface 124. Longitudinally-extending slot or channel 125 is defined through tissue-treating plate 123 and is positioned relative to jaw member 110 or an insulative member 115 disposed in vertical registration therewith when the jaw members 110 and 120 are in the approximated position (FIG. 5). The slot or channel 125 may be defined within an integrally-formed tissue-treating plate 123 or may be defined between two tissue- treating plates that, together, operate as a single treatment surface (not shown). Slot 125 may extend through at least a portion of jaw housing 122, a jaw insert (if so provided), and/or other components of jaw member 120 to enable receipt of thermal cutter assembly 130 at least partially within slot 125.

[0050] Thermal cutter assembly 130, more specifically, is disposed within longitudinally- extending slot 125 such that thermal cutter assembly 130 opposes jaw member 110 in the approximated position. Thermal cutter assembly 130 may be configured to contact jaw member 110 (or another insulative member 115 as mentioned above and as shown in FIG. 4) in the approximated position to regulate or contribute to regulation of a gap distance between tissuetreating surfaces 114, 124 in the approximated position. Alternatively or additionally, one or more stop members (not shown) associated with jaw member 110 and/or jaw member 120 may be provided to regulate the gap distance between tissue-treating surfaces 114, 124 in the approximated position.

[0051] Thermal cutter assembly 130 may be surrounded by the insulative member 115 disposed within slot 125 to electrically and/or thermally isolate thermal cutter assembly 130 from tissue-treating plate 123 (See FIG. 4 versus FIG. 5). As mentioned above, thermal cutter assembly 130 includes an encapsulant 134 that may act in conjunction with or in lieu of insulative member 115. Encapsulant 134 (and insulator 132 as shown in FIG. 6A) is configured cover the sides of the substrate 131 leaving the tissue facing edge 131a of the substrate 131 exposed. Thermal cutter assembly 130 and insulative member 115 may similarly or differently be substantially (within manufacturing, material, and/or use tolerances) coplanar with tissuetreating surface 124, may protrude from tissue-treating surface 124, may be recessed relative to tissue-treating surface 124, or may include different portions that are coplanar, protruding, and/or recessed relative to tissue-treating surface 124.

[0052] Turning back to the thermal cutter assembly 130 and the various methods of manufacturing the same, it is contemplated that the resistive element 133 of the thermal cutter assembly 130 may be manufactured in thin layers that are deposited atop (or otherwise) insulator 132 which is disposed atop substrate 131. For the purposes herein, the resistive element 133 will be described as being deposited onto insulator 132, knowing that insulator, in turn, may be disposed on one or both sides of substrate 131. For example, it is contemplated that resistive element 133 may be deposited onto the insulator 132 via one or more of the following manufacturing techniques: sputtering, thermal evaporation, thermal spraying, cathodic arcing, pulsed laser deposition, electron beam deposition. Other techniques may include: electroless strike or plating and electro-plating, shadow masking.

[0053] Utilizing one or more of these techniques provides a thin layer of thermally conductive resistive material which has the benefit of dissipating heat quickly compared to a traditional thermal cutter assembly 130. Other advantages of thin-layered resistive elements 133 on the thermal cutter assembly 130 include: the ability to heat up quickly, the ability to require less energy to heat up and maintain heat during the cutting process, and the ability to cut tissue in a reduced timeframe compared to traditional electrical cutters.

[0054] Any one of the following materials (or combinations thereof) may be utilized as the resistive element 133: aluminum, copper, chromium, titanium, stainless steel, nickel, chrome, tin, platinum, palladium, gold, nichrome, and Kanthal®. It is contemplated that during manufacturing, combinations of materials may be utilized for a particular purpose or to achieve a particular result. For example, one material may be utilized as a base conductor with a second material used as an outer or inner conductor to act as the heating element. Additional techniques or materials may be added to act as thermal cutter assemblies 130 or resistive elements 133 such as those described with reference to U.S. Patent Application Serial No. 16/785,347 filed February 7, 2020, U.S. Provisional Patent Application Serial No. 62/952,232 filed December 21, 2019, U.S. Patent Application Serial No. 16/838,551 filed April 2, 2020, and U.S. Patent Application Serial No. 16/518,016 filed July 22, 2019, the entire contents of each of which being incorporated by reference herein.

[0055] In other embodiments, materials may be mixed during the application process. In some embodiments, the material used (e.g., Aluminum, copper etc.,) may be thin and still promote a good cutting effect while other materials may have to be thicker to produce the same or similar cutting effect due to the particular material’s level of electrical resistance. In this latter instance, a highly conductive base material may be utilized with the thinner, less conductive material more resistive material to produce a desired effect.

[0056] In embodiments, a biocompatible material (not shown) may be utilized to cover a non-biocompatible material. In other embodiments, the materials may be deposited (or otherwise disposed on insulator 132 in non-uniform layers while still allowing for transitions, e.g., side-to-side transitions. The materials could be deposited (or otherwise disposed on insulator 132) in an alternating fashion and more than one electrical circuit may be employed. [0057] Examples of resistive elements 133 that may be used for thermal cutter assemblies 130 may include single layer resistive elements 133 in the range of about 0.1 micron to about 500 microns. A so-called “thick” film resistive element 133 would be about 30 microns and a “thin” film resistive element 133 would be about 1 micron. Non- conductive, electrically transparent, thermally transparent, or electrically and/or thermally porous materials may also be layered in a similar fashion atop, below or between the resistive elements 133. One or more of these materials may be layered atop the resistive elements 133 to complete the thermal cutter assembly 130 as mentioned above within a specified range.

[0058] Generally, tissue-treating plates 113, 123 are formed from an electrically conductive material, e.g., for conducting electrical energy therebetween for treating tissue, although tissuetreating plates 113, 123 may alternatively be configured to conduct any suitable energy, e.g., thermal, micro wave, light, ultrasonic, etc., through tissue grasped therebetween for energy-based tissue treatment. As mentioned above, tissue-treating plates 113, 123 are coupled to activation switch 80 and electrosurgical generator “G” (FIG. 1) such that energy may be selectively supplied to tissue-treating plates 113, 123 and conducted therebetween and through tissue disposed between jaw members 110, 120 to treat tissue, e.g., seal tissue on either side and extending across thermal cutter assembly 130.

[0059] Thermal cutter assembly 130, on the other hand, is configured to connect to electrosurgical generator “G” (FIG. 1) and second activation switch 90 to enable selective activation of the supply of energy to thermal cutter assembly 130 for heating resistive element 133 which, in turn, heats edge 131a of substrate 131 to thermally cut tissue disposed between jaw members 110, 120, e.g., to cut the sealed tissue into first and second sealed tissue portions. Other configurations including multi-mode switches, other separate switches, etc. may alternatively be provided.

[0060] FIGS. 7A-7C show one embodiment of a thermal cutting assembly 330 that may be disposed within slot 125 defined in one of the jaw members 110, 120 for cutting tissue disposed between jaw members 110, 120 upon activation thereof. The thermal cutting assembly 330 described herein may be initially manufactured straight and then bent for insertion within the slot 125 of jaw member 120 or may be manufactured in a curved configuration, e.g., similar to the curve of the jaw member 120, and then dropped or placed within the slot 125. As mentioned above, insulative member 115 may be inserted within slot 125 and thermal cutter assembly 330 dropped or placed therein.

[0061] FIG. 7A shows an assembled thermal cutting assembly 330 including an elongated substrate 350, an insulator 355, the resistive element 335 composed of one or more traces 335a, 335b and an encapsulant 380 which, together, form the thermal cutting assembly 330. Although designated as traces 335a, 335b, the traces 335a, 335b are technically an electrically resistive loop with two ends 335a, 335b that connect to an energy source through a respective conductive lead or trace (e.g., similar to traces 133al, 133bl of FIG. 6B). The traces 335a, 335b may be disposed on both sides of the substrate 350. Each trace, e.g., trace 335a, may be made of a first metal, e.g., silver that is highly conductive and layered with a second metal that is more resistive, e.g., platinum, which rapidly generates heat upon electrical activation. The traces 335a, 335b connect to opposite pads 335al and 335bl, respectively via electrically conductive connections, (See 133al, 133bl of FIG. 6B above).

[0062] Substrate 350, in turn, is formed from a material that is both thermally and electrically conductive and is configured to rapidly heat upon electrical activation and heating of the traces 335a, 335b as the traces 335a, 335b loop therearound. The traces 335a, 335b may include various geometries to ensure uniform thermal conductive transfer to the substrate 350 upon activation thereof. Edge 350a of the substrate 350 is exposed to tissue when the jaw members 110, 120 are approximated and, upon activation of switch 90, tissue is cut along the thermal cutter assembly 330.

[0063] Thermal cutting assembly 330 may be formed to include one or more mechanical interfaces that facilitate secure engagement within the jaw member 120. For example, and as shown in FIGS. 7A-7C, a distal end 334 of the substrate 350 may include a hook 356 that depends therefrom and that defines a notch 357 that is configured to operably engage a portion 326 of the jaw member 120 (FIG. 8B). Substrate 350 also includes a rear tab 358 that is configured to operably engage a proximal portion 324 of the jaw member 120 upon insertion of the thermal cutting assembly 330 within slot 125. As explained in more detail below, upon insertion of the thermal cutting assembly 330 within slot 125, the opposing mechanical features operate to retain the thermal cutting assembly 330 securely therein. The hook 356 and tab 358 may be located anywhere along the length of the thermal cutting assembly 330 and multiple hooks or tabs are also envisioned. [0064] As best shown in FIGS. 7B and 7C and as mentioned above, thermal cutting assembly 330 includes traces 335a, 335b that extend along substrate 350 between a proximal end 336 and the distal end 334 thereof. Traces 335a, 335b at least thermally connect to substrate 350. More particularly, a proximal end 335a’ of trace 335a is typically more electrically conductive and is configured to electrically connect to an energy source “G” (FIGS. 1 and 6B, e.g., via pad 135a) and extend as trace 335a therefrom toward the distal end 334 of substrate 350. Similarly, a proximal end 335b’ of trace 335b is more electrically conductive and is configured to electrically connect to an energy source “G” (FIGS. 1 and 6B, e.g., via pad 135b). Traces 335a, 335b are more electrically resistive and, as a result thereof, tend to rapidly generate heat (See, e.g., FIG. 6B). Trace 335a loops around the distal end 334 and then trace 335b returns to a proximal end 335bl of trace 335b. As mentioned above, traces 335a, 335b may be composed of a variety of layered conductive and resistive materials to rapidly heat substrate 350 upon activation thereof.

[0065] FIG. 7B shows the dielectric insulator 355 disposed on the same side as the traces 335a, 335b of the substrate 350 to electrically isolate the substrate 350 from the traces 335a, 335b but not thermally isolate the traces 335a, 335b from the substrate 350. Moreover, an encapsulant 380 may be layered (or otherwise disposed) atop both the dielectric insulator 355 and the traces 335a, 335b on one or both sides of the substrate 350. The encapsulant 380 further electrically isolates the traces 335a, 335b from other jaw components, e.g., tissue sealing surfaces 114, 124.

[0066] As mentioned above, the substrate 350 of the thermal cutter assembly 330 includes mechanical retention features, e.g., hook 356 and tab 358, that facilitate engagement and retention within the jaw member, e.g., jaw member 120. More particularly, and as shown in FIGS 8A and 8B, the distal end 334 of the substrate 350 includes a rearwardly facing hook portion 356 that defines a notch 357 (FIG. 7B) configured to operably engage one or more components of the jaw member 120, e.g., spacer (not shown) or jaw support 326 (FIG. 8B).

[0067] During assembly, the hook portion 356 is engaged at an angle to a distal end 322 of jaw member 120 and pulled proximally. The thermal cutter assembly 330 is then properly seated within the slot 125 by angling the thermal cutter assembly 330 in the opposite direction such that the tab 358 engages the proximal portion 324 of the jaw member 120 (FIG. 8B) and secures the thermal cutter assembly 330 within the jaw member 120. When the shaft 12 is thereafter engaged to the jaw member 120 during assembly, the shaft 12 traps the tab 358 in position such that the thermal cutter assembly 330 cannot lift or disengage from the slot 125. Proximal end 336 may also engage the inner peripheral surface of shaft 12 when assembled to prevent the tab 358 from disengaging. Engaging the thermal cutter assembly 330 in this fashion, e.g., simple mechanical fit, helps to minimize thermal conduction from the thermal cutter assembly 330 to the jaw member 120 and the components thereof.

[0068] In embodiments, both sides of the substrate 350 may include a dielectric insulator 355, one or more traces 335a, 335b and/or an encapsulant 380. In other embodiments, substrate 350 may include a dielectric insulator 355, traces 335a, 335b and an encapsulant 380 on one side thereof and simply a dielectric insulator 355 (or dielectric insulator 355 and encapsulant 380) on the opposite side thereof depending upon particular purpose. It is also envisioned that the dielectric insulator 355 may act as a spacer to space the opposing jaw members 110, 120 apart during sealing to create a gap which has been known to ensure effective sealing.

[0069] 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.

Claims

WHAT IS CLAIMED IS:

1. A thermal cutting assembly for a jaw member of a surgical instrument, comprising: an elongated substrate including proximal and distal ends and a cutting edge disposed along an upper surface thereof; a dielectric insulator disposed along at least one side of the substrate and extending at least partially therealong from the proximal to the distal end thereof; at least one resistive element adapted to connect to an energy source and disposed in thermal communication with the substrate, the at least resistive element configured to extend along the dielectric insulator to a distal end portion thereof; and an encapsulant disposed atop both the dielectric insulator and the at least one resistive element, wherein at least the distal end of the substrate includes at least one mechanical interface configured to engage a portion of a jaw member to secure the substrate therein.

2. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 1, wherein the at least one resistive element includes at least one trace composed of aluminum, copper, silver, chromium, titanium, stainless steel, nickel, chrome, tin, platinum, palladium, gold, nichrome, and a ferritic iron-chromium-aluminum alloy.

3. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 2, wherein the at least one trace is layered atop the dielectric insulator.

4. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 3, wherein the at least one resistive element includes at least two traces layered atop one another.

5. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 1 , wherein the at least one mechanical interface includes a hook disposed at the distal end of the substrate, the hook defining a notch configured to operably engage the portion of the jaw member.

6. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 1, wherein the substrate includes at least two mechanical interfaces configured to engage different portions of the jaw member to secure the substrate therein.

7. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 6, wherein a first of the at least two mechanical interfaces includes a hook disposed at the distal end of the substrate, the hook defining a notch configured to operably engage a first portion of the jaw member and a second of the at least two mechanical interfaces includes a tab disposed at a proximal portion of the substrate, the tab configured to engage a second portion of the jaw member.

8. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 7, wherein the hook is configured to engage the first portion of the jaw member in an angular manner to seat the first portion of the jaw member within the notch.

9. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 8, wherein the tab is configured to operably engage the second portion of the jaw member after engagement of the first portion of the jaw member within the notch and proximal movement of the substrate relative to the first portion of the jaw member.

10. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 8, wherein the substrate includes at least one second mechanical interface configured to engage a shaft of the surgical instrument when operably coupled to the jaw member to secure the thermal cutting assembly within the jaw member.

11. A thermal cutting assembly for a jaw member of a surgical instrument, comprising: an elongated substrate including proximal and distal ends and a cutting edge disposed along an upper surface thereof; a dielectric insulator disposed along at least one side of the substrate and extending at least partially therealong from the proximal to the distal end thereof; a first, electrically conductive trace adapted to connect at one end to an energy source and disposed in electrical communication with a first end of a resistive trace, a second end of the resistive trace connected to a second, electrically conductive trace adapted to connect at an opposite end to the energy source, the resistive trace layered atop the dielectric insulator and extending therealong to a distal end portion thereof; and an encapsulant disposed atop the dielectric insulator and the first and second traces, wherein at least the distal end of the substrate includes at least one mechanical interface configured to engage a portion of a jaw member to secure the substrate therein.

12. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 11, wherein at least one of the first or second traces includes at least one of aluminum, copper, silver, chromium, titanium, stainless steel, nickel, chrome, tin, platinum, palladium, gold, nichrome, and a ferritic iron-chromium-aluminum alloy.

13. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 11, wherein the at least one mechanical interface includes a hook disposed at the distal end of the substrate, the hook defining a notch configured to operably engage the portion of the jaw member.

14. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 11 , wherein the substrate includes at least two mechanical interfaces configured to engage different portions of the jaw member to secure the substrate therein.

15. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 14, wherein a first of the at least two mechanical interfaces includes a hook disposed at the distal end of the substrate, the hook defining a notch configured to operably engage a first portion of the jaw member and a second of the at least two mechanical interfaces includes a tab disposed at a proximal portion of the substrate, the tab configured to engage a second portion of the jaw member.

16. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 15, wherein the hook is configured to engage the first portion of the jaw member in an angular manner to seat the first portion of the jaw member within the notch.

17. The thermal cutting assembly for a jaw member of a surgical instrument accordingly to claim 16, wherein the tab is configured to operably engage the second portion of the jaw member after engagement of the first portion of the jaw member within the notch and proximal movement of the substrate relative to the first portion of the jaw member.

18. A method of manufacturing a thermal cutting assembly of a jaw member of a surgical instrument, comprising: disposing a dielectric insulator on at least one side of an elongated substrate having at least one mechanical interface operatively associated therewith configured to engage a portion of a jaw member; disposing at least one resistive element adapted to connect to an energy source and disposed in thermal communication with the substrate along the dielectric insulator; encapsulating the dielectric insulator and the at least one resistive element to form a thermal cutting assembly; and seating the thermal cutting assembly within the jaw member and engaging the at least one mechanical interface of the substrate with the portion of the jaw member.

19. The method of manufacturing a thermal cutting assembly of a jaw member of a surgical instrument accordingly to claim 18, wherein seating the thermal cutting assembly includes: engaging a hook disposed at the distal end of the substrate with a first portion of the jaw member such that the first portion seats within a notch defined within the hook; and engaging a tab disposed at a proximal portion of the substrate with a second portion of the jaw member.

20. The method of manufacturing a thermal cutting assembly of a jaw member of a surgical instrument accordingly to claim 19, wherein the hook engages the first portion of the jaw member in an angular manner.