Multi-modality electrosurgical instruments

Abstract

Electrosurgical instruments and systems configured to inhibit leakage current, minimize the possibility of neuromuscular stimulation, and / or enable safe and effective multi-modality electrosurgical functionality such as, for example, in a tissue sealing mode and / or one or more tissue cutting modes.

Description

Attorney Docket: A0012501WO01 MULTI-MODALITY ELECTROSURGICAL INSTRUMENTS CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No.63 / 665,488 filed June 28, 2024, entitled “Multi-Modality Electrosurgical Instruments,” and U.S. Provisional Application No. 63 / 674,353 filed July 23, 2024, entitled “Multi-Modality Electrosurgical Instruments,” and which applications are incorporated herein by reference in their entireties. To the extent appropriate a claim of priority is made to each of the above applications. FIELD

[0002] This disclosure relates to electrosurgical instruments and, more specifically, to multi- modality electrosurgical instruments for energy-based tissue treatment such as, for example, tissue sealing and / or one or more modes of tissue cutting. BACKGROUND

[0003] 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 element may be provided to cut tissue using energy, e.g., thermal, Radio Frequency (RF) current, ultrasonic, light, or other suitable energy.

[0004] Energy-based elements are also utilized in various other surgical instruments and / or to otherwise facilitate treating tissue, e.g., coagulating tissue, sealing tissue, cutting tissue, etc., using energy, e.g., thermal, RF current, ultrasonic, light, or other suitable energy. SUMMARY

[0005] As used herein, the term “distal” refers to the portion that is being described which is farther from an operator (whether a human surgeon or a surgical robot), while the term “proximal” refers to the portion that is being described which is closer to the operator. Terms including “generally,” “about,” “substantially,” and the like, as utilized herein, are meant to encompass variations, e.g., manufacturing tolerances, material tolerances, use and environmental tolerances, measurement variations, design variations, and / or other variations, up to and including plus or minus 10 percent. To the extent consistent, any of the aspectsAttorney Docket: A0012501WO01 described herein may be used in conjunction with any or all of the other aspects described herein.

[0006] Provided in accordance with aspects of this disclosure is an electrosurgical instrument including a housing, a shaft extending distally from the housing, an end effector assembly coupled to a distal end of the shaft, a plug configured to connect to an electrosurgical generator, and a cable connecting the plug and the housing. The end effector assembly includes first, second, and third electrodes, the plug includes first, second, and third contacts, and first, second, and third electrical pathways extend from the end effector assembly through the shaft, the housing, and the cable to the plug to electrically connect the first, second, and third electrodes with the first, second, and third contacts, respectively. A common mode choke assembly is disposed within the housing and coupled to the first and second electrical pathways such that leakage current along the first and second electrical pathways is inhibited when the third electrode is energized.

[0007] In an aspect of this disclosure, the common mode choke assembly defines a parallel LC resonant topology.

[0008] In another aspect of this disclosure, the common mode choke assembly includes a plurality of common mode chokes arranged in series.

[0009] In another aspect of this disclosure, the common mode choke assembly is configured to dissipate power during 5 minutes of use without increasing a temperature of the housing by more than 5ºC, more than 10ºC, or more than 15ºC.

[0010] In yet another aspect of this disclosure, an inductor core of a common mode choke of the common mode choke assembly at least one of defines a diameter equal to or less than about 0.60 inches, defines a thickness equal to or less than 0.25 inches, or defines a weight equal to or less than 1.00 ounces.

[0011] In still another aspect of this disclosure, the end effector assembly includes first and second jaw members. At least one of the first or second jaw members is movable relative to the other between a spaced-apart position and an approximated position for grasping tissue therebetween. In such aspects, the first electrode may be disposed on the first jaw member, the second electrode may be disposed on the second jaw member, and / or the third electrode may be supported by one of the first or second jaw members. Additionally or alternatively, the first and second electrodes may be configured to conduct current therebetween and through tissue grasped between the first and second jaw members to seal the grasped tissue and / or the third electrode may be configured to conduct current to tissue in contact with the third electrode to cut the tissue in contact with the third electrode.Attorney Docket: A0012501WO01

[0012] In still yet another aspect of this disclosure, the housing includes a handle configured to be grasped by a surgeon and at least one manual actuator configured to be actuated by a surgeon. Alternatively, the housing may be configured to connect to a robotic arm of a surgical robotic system and may include at least one input coupler configured to be actuated by the surgical robotic system.

[0013] Another electrosurgical instrument provided in accordance with this disclosure includes a housing, a shaft extending distally from the housing, an end effector assembly coupled to a distal end of the shaft and including first, second, and third electrodes, a plug including first, second, and third contacts configured to connect to an electrosurgical generator having first and second ports, a cable connecting the plug and the housing, and first, second, and third electrical pathways extending from the end effector assembly through the shaft, the housing, and the cable to the plug to electrically connect the first, second, and third electrodes with the first, second, and third instrument terminals, respectively. In a first mode of operation, the first and second contacts are connected to the first and second ports, respectively, for conducting current between the first and second electrodes and through tissue disposed therebetween to treat the tissue disposed between the first and second electrodes. In a second mode of operation, the third contact is connected to one of the first or second generator terminals, or another terminal, for conducting current from the third electrode to tissue in contact with the third electrode to treat the tissue in contact with the third electrode. The third electrical pathway incorporates a capacitance to minimize the possibility of neuromuscular stimulation.

[0014] In an aspect of this disclosure, the third electrical pathway includes at least one series capacitor. In aspects, the third electrical pathway includes a plurality of series capacitors.

[0015] In another aspect of this disclosure, the at least one series capacitor is disposed in the housing and / or the plug.

[0016] In another aspect of this disclosure, the plug further includes at least one signal port configured to communicate a signal to the electrosurgical generator to supply current in the first mode of operation or the second mode of operation.

[0017] In still another aspect of this disclosure, the end effector assembly includes first and second jaw members. At least one of the first or second jaw members is movable relative to the other between a spaced-apart position and an approximated position for grasping tissue therebetween. In such aspects, wherein the first electrode may be disposed on the first jaw member, the second electrode may be disposed on the second jaw member, and / or the third electrode may be supported by one of the first or second jaw members. Additionally orAttorney Docket: A0012501WO01 alternatively, the first and second electrodes may be configured to conduct current therebetween and through tissue grasped between the first and second jaw members to seal the grasped tissue and / or the third electrode may be configured to conduct current to tissue in contact with the third electrode to cut the tissue in contact with the third electrode.

[0018] In yet another aspect of this disclosure, the housing includes a handle configured to be grasped by a surgeon and at least one manual actuator configured to be actuated by a surgeon. Alternatively, the housing may be configured to connect to a robotic arm of a surgical robotic system and include at least one input coupler configured to be actuated by the surgical robotic system.

[0019] An electrosurgical system provided in accordance with this disclosure includes an end effector assembly including an electrode energizable in each of a first manner and a second manner, and first and second electrical pathways configured to electrically connect the electrode to an electrosurgical generator. The first and second electrical pathways are electrically isolated from one another. Energizing the electrode in the first manner includes conducting current along the first electrical pathway to the electrode for transmitting the current to tissue. Energizing the electrode in the second manner includes conducting current along the second electrical pathway to the electrode for transmitting the current to tissue.

[0020] In an aspect of this disclosure, when the electrode is energized in the first manner, current is transmitted from the electrode through tissue to at least one other electrode of the end effector assembly and / or when the electrode is energized in the second manner, current is transmitted from the electrode through tissue to at least one other electrode remote from the end effector assembly.

[0021] In another aspect of this disclosure, at least one other electrical pathway is configured to connect the at least one other electrode of the end effector assembly to an electrosurgical generator. In such aspects, a common mode choke assembly may be coupled to both the second electrical pathway and the at least one other electrical pathway.

[0022] In yet another aspect of this disclosure, the at least one other electrode of the end effector assembly includes first and second other electrodes, wherein the at least one other electrical pathway includes third and fourth electrical pathways configured to connect the first and second other electrodes, respectively, to an electrosurgical generator, and wherein the common mode choke assembly is coupled to each of the second, third, and fourth electrical pathways.

[0023] In yet another aspect of this disclosure, the common mode choke assembly is electrically isolated from the first electrical pathway.Attorney Docket: A0012501WO01

[0024] In yet another aspect of this disclosure, the end effector assembly includes first and second jaw members. At least one of the first or second jaw members is movable relative to the other between a spaced-apart position and an approximated position for grasping tissue therebetween.

[0025] In yet another aspect of this disclosure, the electrode is energized in the first manner when the first and second jaw members are disposed in the spaced-apart position, and the electrode is energized in the second manner when the first and second jaw members are disposed in the approximated position.

[0026] In yet another aspect of this disclosure, the electrosurgical system further includes a at least one plug including first and second contacts configured to connect to the electrosurgical generator, wherein the first and second electrical pathways connect to the first and second contacts, respectively. In aspects, the first and second contacts are disposed on one plug. In other aspects, the first and second contacts are disposed on first and second plugs, respectively.

[0027] In yet another aspect of this disclosure, at least one feedback device, e.g., a sensor, activation assembly, switch, etc., is provided. In such aspects, the at least one plug may further include a communication contact and information indicative of whether to energize the electrode in the first manner or the second manner is communicated from the at least one feedback device to an electrosurgical generator via the communication contact.

[0028] In yet another aspect of this disclosure, the electrosurgical system further includes the electrosurgical generator, wherein: the electrosurgical generator is configured to output current to the first contact when it is determined that the end effector assembly is in the first configuration, and wherein the electrosurgical generator is configured to output monopolar current to the second contact when it is determined that the end effector assembly is in the second configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other aspects and features of this 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.

[0030] FIG. 1 illustrates a surgical system in accordance with this disclosure including an electrosurgical instrument and an electrosurgical generator;

[0031] FIG.2 is a side view of a proximal portion of the electrosurgical instrument of FIG. 1 with a portion of the housing removed to illustrate internal components;Attorney Docket: A0012501WO01

[0032] FIG. 3 is a transverse, cross-sectional view of an end effector assembly of the electrosurgical instrument of FIG.1;

[0033] FIGS.4A and 4B are side views of the end effector assembly of the electrosurgical instrument of FIG.1 with jaw members of the end effector assembly disposed in spaced-apart and approximated positions, respectively;

[0034] FIG. 5 is a schematic illustration of a surgical robotic system in accordance with this disclosure;

[0035] FIG.6 is a perspective view of an electrosurgical instrument in accordance with this disclosure configured for use with the surgical robotic system of FIG. 5;

[0036] FIG.7 is a schematic illustration of the electrosurgical generator of FIG.1;

[0037] FIG.8 is a schematic illustration of a plug of the electrosurgical instrument of FIG. 1;

[0038] FIG. 9 is a schematic illustration of electrical features within the housing of the electrosurgical instrument of FIG.1;

[0039] FIG.10 is a schematic illustration of the end effector assembly of the electrosurgical instrument of FIG.1;

[0040] FIG.11 is a top view of a common mode choke in accordance with this disclosure;

[0041] FIG.12 is a top view of a plurality of common mode chokes in accordance with this disclosure;

[0042] FIG.13 is a circuit diagram of a common mode choke assembly in accordance with this disclosure;

[0043] FIG. 14 is a schematic illustration of an electrosurgical circuit in accordance with this disclosure;

[0044] FIG. 15 is a schematic illustration of electrosurgical circuits in accordance with other aspects of this disclosure;

[0045] FIG.16 is a flow diagram of a method in accordance with aspects of this disclosure; and

[0046] FIG.17 is a schematic illustration of electrosurgical circuits in accordance with this disclosure incorporating a common mode choke assembly.Attorney Docket: A0012501WO01 DETAILED DESCRIPTION

[0047] Referring to FIG. 1, an electrosurgical system 2 provided in accordance with the present disclosure includes an electrosurgical instrument 10 and an electrosurgical generator 200. Electrosurgical instrument 10 includes a housing 20, a handle assembly 30, a rotating assembly 40, a first activation assembly 50, a second activation assembly 60, and an end effector assembly 70. Instrument 10 further includes a shaft 12 that defines a longitudinal axis “A-A” and has a proximal end portion 12a operatively engaged to housing 20 and a distal end portion 12b operably engaged to end effector assembly 70. End effector assembly 70 may be configured to include first and second jaw members 72, 74, at least one of which is pivotable relative to the other about a pivot 150 to grasp tissue to enable sealing and / or dividing of the grasped tissue, although other end effector assembly configurations are also contemplated. Further, as described in greater detail hereinbelow, end effector assembly 70 includes three or more electrodes such as, for example: a first electrode defined by a tissue contacting surface 146 of jaw member 72 (see FIG. 3), a second electrode defined by tissue contacting surface 148 of jaw member 74 (see FIG. 3), and a third electrode defined by a cutting element 149 supported by jaw member 74. Other suitable configurations and / or numbers of electrodes are also contemplated.

[0048] Instrument 10 also includes an electrosurgical cable 14 extending from housing 20 to a plug 16 configured to connect instrument 10 to electrosurgical generator 200. More specifically, plug 16 is configured to engage a port 230 of generator 200 to enable generator 200 to communicate with instrument 10 and control the supply of electrosurgical energy to the electrodes of end effector assembly 70 of instrument 10, e.g., for sealing and / or cutting tissue grasped between first and second jaw members 72, 74 and / or for cutting tissue in contact with cutting element 149, e.g., with jaw members 72, 74 disposed in a spaced apart position. Electrosurgical instrument 10 and electrosurgical generator 200, more specifically, and as detailed below, enable selective activation of two of the electrodes of end effector assembly 70 in a sealing mode of operation wherein the two electrodes, e.g., tissue contacting surfaces 146, 148 of jaw members 72, 74 (see FIG. 3), are energized to different potentials to conduct electrosurgical energy, e.g., Radio Frequency (RF) current, therebetween and through tissue grasped between first and second jaw members 72, 74 to treat, e.g., seal, the tissue, and in one or more cutting modes of operation wherein the third electrode, e.g., cutting element 149, is energized with electrosurgical energy, e.g., RF current, to cut tissue in contact with the electrode to treat, e.g., cut, tissue.Attorney Docket: A0012501WO01

[0049] Electrosurgical generator 200 includes a housing 202, a display 210, a plurality of user interface features 220 (e.g., buttons, touch-screens, switches, etc.), and a plurality of ports 230. Each port 230 is configured to receive a plug of a surgical instrument, e.g., plug 16 of instrument 10. One or more of ports 230 may be universal ports configured to receive plugs of instruments having different configurations, different energy modalities, different energy parameters, etc., and / or one or more of ports 230 may be dedicated ports configured to receive plugs of instruments of a particular configuration, energy modality(s), energy parameters, etc.

[0050] Generator 200 further includes one or more generator modules 240 (FIG. 7) each configured to generate suitable energy for output through one or more ports 230 to a connected instrument(s). For example, the one or more generator modules 240 (FIG.7) may be configured to generate first and second RF current signals for output through the port 230 connected to instrument 10 to end effector assembly 70 of instrument 10 for energizing the first and second electrodes of end effector assembly 70 for sealing tissue grasped between jaw members 72, 74 in the sealing mode of operation and / or may generate an RF current signal for output through the port 230 connected to instrument 10 to energize the third electrode of end effector assembly 70 of instrument 10 in the cutting mode(s) of operation for cutting tissue in contact with the third electrode. Generator 200 also includes one or more controllers 250 (FIG. 7) such as, for example, to control the various modules, components, and features of generator 200.

[0051] Continuing with reference to FIG. 1, first and second activation assemblies 50, 60 of instrument 10 are configured to signal generator 200 to initiate the supply of electrosurgical energy to the electrodes of end effector assembly 70 in accordance with a selected mode of operation. First and second activation assemblies 50, 60 may each include, for example, an activation button 52, 62 supported by housing 20 and movable between an un-actuated position and an actuated position to thereby transition an underlying electrical switch (not shown) between a first state and a second state. The electrical switches of activation assemblies 50, 60, in turn, are configured to electrically connect to generator 200 to enable communication of the state of the electrical switches to generator 200. In aspects, first activation assembly 50 is configured to signal generator 200 to initiate the supply of RF current to end effector assembly 70 in a first mode, e.g., the sealing mode, and / or second activation assembly 60 is configured to signal generator 200 to initiate the supply of RF current to end effector assembly 70 in one or more second modes, e.g., one or more cutting modes.

[0052] Generator 200 may be configured to read an output, e.g., the presence of a resistance, voltage, current, etc. and / or a value of the resistance, voltage, current, etc., to detect the state of the electrical switches and, thus, to detect whether the user has activated either ofAttorney Docket: A0012501WO01 the activation buttons 52, 62 and, if so, what state or mode has been activated. In aspects, generator 200 reads the first state of an electrical switch as corresponding to an un-activated state and the second state of an electrical switch as corresponding to an activated state. Alternatively, activation button 52 and / or activation button 62 may include three or more discrete stages or may be continuous buttons such that the underlying electrical switches include three or more outputs capable of being read by generator 200. In such aspects, the outputs may include at least a first output corresponding to an un-activated state, a second output corresponding to a first activated state, and a third output corresponding to a second activated state. The activated states may differ in terms of energy parameters implemented (e.g., power, voltage, current, etc.), energy control algorithms implemented, energy modality implemented (e.g., sealing vs. cutting), or in any other suitable manner. Further, although first and second activation assemblies 50, 60 are detailed, it is contemplated that any suitable configurations and / or combinations of activation assemblies may be provided to enable selection of a mode of operation and / or activation of a mode of operation.

[0053] Referring to FIGS. 1 and 2, handle assembly 30 includes a fixed handle 32 and a movable handle 34. Fixed handle 32 is integrally associated with housing 20 and movable handle 34 is movable relative to the fixed handle 32 to actuate a drive assembly 80 of instrument 10. Movable handle 34 has an upper end portion 34a that is pivotally secured within housing 20 and operably engaged with a drive assembly 80 including a plurality of links 82, a carriage 84, a compression spring 86, and a drive tube 88. Upper end portion 34a of movable handle 34 operably couples to links 82 that cooperate to move carriage 84 distally against compression spring 86 in response to actuation of movable handle 34 towards fixed handle 32. Movement of carriage 84 distally against compression spring 86, in turn, regulates translation of drive tube 88 through shaft 12 and relative to end effector assembly 70 to pivot jaw members 72, 74 towards the approximated position to grasp tissue between jaw members 72, 74 and regulate the closure force applied to tissue grasped between jaw members 72, 74. More specifically, movement of carriage 84 distally against compression spring 86 initially urges compression spring 86 to translate distally to thereby translate drive tube 88 distally through shaft 12 to urge jaw member 72 to pivot about pivot pin 150 and relative to jaw member 74 from a spaced-apart position (FIG. 4A) towards an approximated position (FIG. 4B) to grasp tissue between first and second jaw members 72, 74 and apply a closure force to the grasped tissue. As an alternative to distal movement of drive tube 88 approximating closing jaw members 72, 74, it is also contemplated that the opposite configuration be provided, e.g., wherein proximal movement of drive tube 88 approximates jaw members 72, 74, or that other suitable closureAttorney Docket: A0012501WO01 mechanisms be provided, e.g., wherein rotation of a drive element approximates jaw members 72, 74.

[0054] Upon reaching a threshold closure force applied to tissue grasped between first and second jaw members 72, 74, further movement of carriage 84 distally against compression spring 86, e.g., in response to further actuation of movable handle 34 towards fixed handle 32, compresses compression spring 86 rather than translating compression spring 86 distally (due to the resistive force applied by tissue inhibiting further closure of jaw members 72, 74) such that first and second jaw members 72, 74 are maintained in position grasping tissue therebetween. In this manner, the closure force applied to tissue grasped between jaw members 72, 74 is regulated to maintain a closure force or closure force within a closure force range.

[0055] Continuing with reference to FIGS. 1 and 2, movable handle 34 includes a flange 36 extending proximally from a lower end portion 34b of movable handle 34. Flange 36 is configured to extend through an aperture 31 defined within fixed handle 32 and ultimately engage a latch 38 within fixed handle 32 that is configured to selectively lock and unlock the fixed and movable handles 32, 34 relative to one another upon sufficient actuation of movable handle 34. Upon initial movement of flange 36 through aperture 31 to engage latch 38, in response to an initial actuation of movable handle 34 towards fixed handle 32, fixed and movable handles 32, 34 are locked relative to one another to thereby latch first and second jaw members 72, 74 in the approximated configuration, e.g., wherein compression spring 86 is compressed to maintain the closure force or a closure force within the closure force range.

[0056] Upon subsequent movement initial of flange 36 within aperture 31, in response to a subsequent actuation of movable handle 34 towards fixed handle 32, flange 36 is disengaged from latch 38 such that fixed and movable handles 32, 34 are unlocked permitting return of movable handle 34 towards its initial position and return of jaw members 72, 74 towards the spaced apart position. In aspects, flange 36 and latch 38 are omitted and movable handle 34 is manually maintained in approximation with fixed handle 32 to thereby maintain first and second jaw members 72, 74 in the approximated position applying a closure force to tissue grasped therebetween.

[0057] Rotating assembly 40 is engaged with shaft 12 within housing 20 and extends outwardly from either side of housing 20 to enable a user to manually control the orientation of shaft 12 and thus, end effector assembly 70, relative to housing 20. In aspects, rotating assembly 40 is infinitely rotatable in either direction about the longitudinal axis “A-A” to similarly rotate end effector assembly 70 relative to housing 20. Alternatively, rotating assembly 40 may have a defined range of motion.Attorney Docket: A0012501WO01

[0058] Turning to FIGS. 3-4B, each jaw member 72, 74 of end effector assembly 70 includes a proximal flange 143a, 145a and a distal body 143b, 145b, respectively. Distal bodies 143b, 145b define opposed tissue contacting surfaces 146, 148, respectively, which, as noted above, may define the first and second electrodes of end effector assembly 70. Proximal flanges 143a, 145a are pivotably coupled to one another about a pivot 150 defined through the proximal flange 143a, 145a of at least one of the jaw members 72, 74 to enable pivoting of jaw member 72 relative to jaw member 74 between the spaced apart position (FIG. 4A) and the approximated position (FIGS.3 and 4B) for grasping tissue between tissue contacting surfaces 146, 148. As an alternative to this unilateral configuration, a bilateral configuration may be provided whereby both jaw members 72, 74 are pivotable relative to one another and shaft 12 (FIG. 1). Alternatively, the above detailed configuration may be reversed, e.g., wherein jaw member 72 is the fixed jaw member and jaw member 74 is movable relative to jaw member 72. Other suitable jaw actuation mechanisms (for bilateral and / or unilateral jaw configurations) are also contemplated.

[0059] In aspects, tissue contacting surfaces 146, 148 of jaw members 72, 74, respectively, are defined by respective tissue contacting plates 166, 168 disposed on the opposing surfaces of distal bodies 143b, 145b of jaw members 72, 74, respectively. Further, jaw member 74 supports cutting element 149, which, as noted above, may define the third electrode of end effector assembly 70. Cutting element 149, more specifically, is supported in a slot 160 defined through tissue contacting surface 148 (and through tissue contacting plate 168 and a portion of distal body 145b of jaw member 74), while jaw member 72 includes an insulator 162 disposed in slot 161 defined through tissue contacting surface 146 (and through tissue contacting plate 166 and a portion of distal body 143b of jaw member 72) and configured to oppose cutting element 149 in the approximated position of jaw members 72, 74 (FIGS. 3 and 4B). Tissue contacting surfaces 146, 148 may define substantially U-shaped configurations wherein the slots 161, 160 defined therethrough terminate at positions proximally spaced from the distal ends of tissue contact surfaces 146, 148.

[0060] Cutting element 149 protrudes from jaw member 74 to or beyond tissue contacting plate 168 and towards jaw member 72. Insulator 162 may be substantially flush with tissue contacting surface 146 of tissue contacting plate 166, may be recessed relative thereto, or may protrude from tissue contacting surface 146 of tissue contacting plate 166 towards jaw member 74. Insulator 162 and jaw member 72 are configured, in conjunction with cutting element 149, such that, in the approximated position of jaw members 72, 74 (FIGS. 3 and 4B), cutting element 149 is urged into (and, in aspects, at least partially compresses) insulator 162 (withAttorney Docket: A0012501WO01 tissue grasped therebetween), thus facilitating electrical tissue cutting upon activation of cutting element 149. The contact between cutting element 149 and insulator 162 may also maintain a spacing between tissue contacting surfaces 146, 148 to inhibit electrical shorting via contact therebetween. Alternatively or additionally, either or both jaw member 72, 74 may further include one or more stop members (not shown) disposed on or otherwise associated with either or both tissue-contacting surfaces 146, 148 to maintain a minimum gap distance or gap distance within a minimum gap distance range between tissue contacting surfaces 146, 148 when jaw members 72, 74 are disposed in the approximated position, thus inhibiting electrical shorting.

[0061] Continuing with reference to FIGS. 3-4B, either or both jaw members 72, 74 may include a structural jaw support 172, 174 defining the respective proximal flange 143a, 145a of the jaw member 142, 144 and extending into the respective distal body 143b, 145b. In such configurations, distal body 143b, 145b of either or both jaw members 72, 74 may further include jaw housings 173, 175 surrounding structural jaw supports 172, 174 and supporting tissue contacting plates 166, 168, respectively, thereon. Jaw housings 173, 175 may be formed from insulative materials and, in aspects, may be overmolded about jaw supports 172, 174 and a portion of tissue contacting plates 166, 168 to form jaw members 72, 74 and secure the components thereof to one another. In other configurations, jaw housings 173, 175 are conductive and electrically isolated from the other components of jaw members 72, 74 via suitable insulation.

[0062] Alternatively or additionally, either or both jaw members 72, 74 may be formed from a monolithic, electrically conductive piece of material defining the structural jaw support, tissue contacting surface, and jaw housing thereof. At least a portion of the jaw housing, in such configurations, may be coated with an insulative material. Further, with respect to configurations where jaw member 74 is formed from a monolithic piece of material, cutting element 149 may be electrically isolated from the remainder of jaw member 74, e.g., via an insulator disposed therebetween. Thus, as utilized herein, reference to jaw housings 173, 175 includes insulative jaw housings, conductive jaw housings, and / or monolithic jaw structures defining jaw housings. Further, both jaw members 72, 74 may be similarly configured or may define different configurations, such as any combination of the jaw configurations detailed herein.

[0063] Tissue contacting surfaces 146, 148 of jaw members 72, 74, respectively, are at least partially formed from an electrically conductive material and are energizable to different potentials to enable the conduction of RF electrical energy through tissue graspedAttorney Docket: A0012501WO01 therebetween, e.g., to seal tissue grasped between jaw members 72, 74. More specifically, and with additional momentary reference to FIGS. 1 and 8-10, instrument 10 defines first and second electrical pathways 803, 805 from plug 16 through cable 14, housing 20, and shaft 12 to end effector assembly 70 that may include lead wires, contacts, and / or electrically conductive components to enable electrical connection of tissue contacting surfaces 146, 148 of jaw members 72, 74, respectively, to generator 200 for supplying RF current to tissue contacting surfaces 146, 148 to treat, e.g., seal, tissue grasped between tissue contacting surfaces 146, 148.

[0064] Cutting element 149 is also at least partially formed from an electrically conductive material and defines an energizable electrode configured to conduct RF current to tissue in contact therewith, e.g., to cut the tissue in contact with cutting element 149. Cutting element 149, more specifically, may be energized to cut tissue grasped between jaw member 72, 74 and disposed between cutting element 149 and insulator 162. Cutting element 149 may additionally or alternatively be used to cut tissue in an open jaw configuration, e.g., with jaw members 72, 74 disposed in the spaced apart position. With additional momentary reference to FIGS.1 and 8-10, instrument 10 defines a third electrical pathway 807 from plug 16 through cable 14, housing 20, and shaft 12 to end effector assembly 70 that may include lead wires, contacts, and / or electrically conductive components to enable electrical connection of cutting element 149 to generator 200 for supplying RF current to cutting element 149 to treat, e.g., cut, tissue in contact with cutting element 149. The RF current transmitted to cutting element 149 may be returned to generator 200 to complete the circuit via a remote return device such as a return pad 110 (FIG.10) or a local return device such as another portion of end effector assembly 70 or a separate instrument (not shown), e.g., a tenaculum, a probe, etc.

[0065] Turning to FIGS. 5 and 6, while aspects and features of the present disclosure are illustrated and described above as being utilized with a handheld electrosurgical instrument, the aspects and features of the present disclosure are likewise applicable to electrosurgical instruments for surgical robotic systems. Such systems employ various robotic elements to assist the user and allow remote operation (or partial remote operation) of surgical instrumentation. Various robotic arms, gears, cams, pulleys, electric and mechanical motors, etc. may be employed for this purpose and may be designed with a robotic surgical system to assist the user during the course of an operation or treatment. Such robotic systems may include remotely steerable systems, automatically flexible surgical systems, remotely flexible surgicalAttorney Docket: A0012501WO01 systems, remotely articulating surgical systems, wireless surgical systems, modular or selectively configurable remotely operated surgical systems, etc.

[0066] Referring to FIG. 5, a robotic surgical system provided in accordance with the present disclosure is shown generally identified by reference numeral 1000. Aspects and features of robotic surgical system 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.

[0067] Robotic surgical system 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 / or video images; and manual input devices 1007, 1008, by means of which a surgeon may be able to telemanipulate robot arms 1002, 1003. 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 system 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.

[0068] 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, a surgical tool “ST” including an end effector assembly 1100. One end effector assembly 1100 may be similar to end effector assembly 70 (FIGS. 3-4B), although other suitable end effector assemblies for coupling to attaching device 1009 are also contemplated. The other end effector assembly 1100 may be any end effector assembly, e.g., of an endoscopic camera, other surgical tool, etc. Robot arms 1002, 1003 and end effector assemblies 1100 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 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.

[0069] With reference to FIG. 6, a surgical instrument 310 provided in accordance with the present disclosure generally includes a housing 320, a shaft 330 extending distally from housing 320, an end effector assembly 340 extending distally from shaft 330, and an actuation assembly 350 disposed within housing 320 and operably associated with end effector assemblyAttorney Docket: A0012501WO01 340. Instrument 310 is detailed herein as an articulating electrosurgical instrument configured for use with a surgical robotic system, e.g., as a surgical tool “ST” of surgical robotic system 1000 (FIG.5).

[0070] Housing 320 of instrument 310 encloses actuation assembly 350 therein. Housing 320 may be formed from first and second housing components 322a, 322b and includes a proximal face place 324 defining through holes through which input couplers (not shown) of actuation assembly 350 extend to enable a robotic arm, e.g., of surgical robotic system 1000 (FIG. 5), to couple to actuation assembly 350 and selectively actuate the various features thereof. A pair of latch levers 326 (only one of which is illustrated in FIG. 6) extending outwardly from opposing sides of housing 320 enable releasable engagement of housing 320 with the robotic arm. A window 328 defined through housing 320 permits thumbwheel 360 to extend therethrough to enable manual manipulation of thumbwheel 360 from the exterior of housing 320 to permit manual opening and closing of end effector assembly 340.

[0071] Shaft 330 of instrument 310 includes a distal clevis segment 332, a proximal segment 334, and an articulating section 336 disposed between the distal clevis segment 332 and proximal segment 334. Articulating section 336 includes one or more articulating components 337, e.g., links, joints, etc. A plurality of articulation cables 338, e.g., four (4) articulation cables, or other suitable actuators, extend through articulating section 336. More specifically, articulation cables 338 are operably coupled to distal clevis segment 332 of shaft 330 at the distal ends thereof and extend proximally from distal clevis segment 332 of shaft 330, through articulating section 336 of shaft 330 and proximal segment 334 of shaft 330, and into housing 320, wherein articulation cables 338 operably couple with an articulation subassembly of actuation assembly 350 to enable selective articulation of distal clevis segment 332 (and, thus end effector assembly 340) relative to proximal segment 334 and housing 320, e.g., about at least two axes of articulation (yaw and pitch articulation, for example).

[0072] End effector assembly 340 includes first and second jaw members 342, 344, respectively, pivotably connected about a pivot pin 346. Jaw members 342, 344 may be configured similar to and incorporate any of the features of jaw members 72, 74 (FIGS.3-4B), as detailed above.

[0073] A drive rod 384 is operably coupled to end effector assembly 340 such that longitudinal actuation of drive rod 384 pivots jaw member 342 relative to jaw member 344 between spaced apart and approximated positions. Drive rod 384 extends proximally from end effector assembly 340 through shaft 330 and into housing 320 wherein drive rod 384 is operably coupled with a jaw drive subassembly of actuation assembly 350 to enable selectiveAttorney Docket: A0012501WO01 actuation of end effector assembly 340 to grasp tissue therebetween and apply a jaw force to the grasped tissue. The jaw drive subassembly may be configured similar to drive assembly 80 (FIG.2) detailed above except that suitable gearing, pulleys, linkages, and / or other components are utilized to move the compression spring 86 (FIG. 2) and, thus, drive rod 384, in response to a rotational input from a robotic arm rather than manual actuation of movable handle 34 (FIG.1).

[0074] Actuation assembly 350 of instrument 310, as noted above, is configured to operably interface with surgical robotic system 1000 (FIG.5) when instrument 310 is mounted on a robotic arm thereof, to enable robotic operation of actuation assembly 350 to provide the above detailed functionality. That is, the surgical robotic system selectively provides inputs, e.g., rotational inputs to the input couplers of actuation assembly 350 to articulate end effector assembly 340 and grasp tissue between jaw members 342, 344.

[0075] Continuing with reference to FIG. 6, instrument 310 further includes an electrosurgical cable 314 extending from housing 320 to a plug 316 configured to connect instrument 310 to electrosurgical generator 200 (FIG. 1), similarly as detailed above with respect to instrument 10 (FIG. 1). A plurality of electrical pathways, e.g., three electrical pathways, extend from plug 316 through cable 314, housing 320, and shaft 330 to end effector assembly 340 to connect to a plurality of electrodes of end effector assembly 340, e.g., first, second, and third electrodes, similarly as detailed above with respect to instrument 10 (FIG.1). The electrical pathways may include lead wires, contacts, and / or electrically conductive components to enable electrical connection of the electrodes of end effector assembly 340, e.g., first and second electrodes associated with the first and second jaw members 342, 344 and a third, cutting electrode engaged with one of the jaw members 344, thus enabling multi-modality operation of end effector assembly 340 similarly as detailed above with respect to instrument 10 (FIG.1).

[0076] Turning to FIG. 7, as noted above, generator 200 includes one or more generator modules, e.g., RF generator module 240, configured to generate suitable energy for output through one or more ports 230 to a connected instrument(s). RF generator module 240 of generator 200, more specifically, includes sensor circuitry 242, a high voltage DC power supply (“HVPS”) 244 and an RF output stage 246. HVPS 244 provides high voltage DC power to RF output stage 246 which converts the high voltage DC power into RF current for transmission via first and second output pathways 247a, 247b to contacts 248 of one of the ports 230 for delivery of RF current to an instrument connected to the port 230, e.g., instrument 10 (FIG. 1). In particular, RF output stage 246 may generate sinusoidal waveforms of highAttorney Docket: A0012501WO01 frequency RF current. RF output stage 246 may be configured to generate a plurality of waveforms having various duty cycles, peak voltages, crest factors, and other parameters, depending on a particular mode of operation and / or electrical feedback data.

[0077] Controller 250 includes a processor 252 (e.g., a microprocessor) operably connected to a non-transitory computer-readable storage medium such as a memory 254 which may be volatile type memory (e.g., RAM) and / or non-volatile type memory (e.g., flash media, disk media, etc.). Processor 252 is operably connected to HVPS 244 and / or RF output stage 246 allowing controller 250 to control the output of generator module 240. Sensor circuitry 242 is operably coupled between RF output stage 246 and output pathways 247a, 247b to enable sensor circuitry 242 to determine one or more parameters, e.g., tissue impedance, output current, and / or voltage, etc. associated with the supply of energy. Sensor circuitry 242 provides feedback, e.g., based on the sensed parameter(s), to controller 250 which, in turn, selects an energy-delivery algorithm, modifies an energy-delivery algorithm, adjusts energy-delivery parameters, and / or determines a status of an energy-delivery algorithm based thereon.

[0078] Controller 250 of generator 200 may also monitor signal(s) provided by one or more communication pathways 247c, 247d connected to contacts 248 of port 230 to communicate with the connected instrument, e.g., to communicate with activation assemblies 50, 60 of instrument 10 (FIGS.1 and 2) and / or a sensor 90 (FIG.9) of instrument 10 (FIGS.1 and 2), to determine a state and / or condition associated with instrument 10 (FIGS. 1 and 2). This may enable controller 250 to determine, for example, whether to activate the supply of RF current in a first mode of operation, whether to activate the supply of RF current in a second mode of operation, and / or to ascertain a state of end effector assembly 70 such as, for example, whether jaw members 72, 74 are disposed in the approximated position (e.g., as determined by a jaw position sensor such as sensor 90 (FIG. 9), although other suitable sensors are also contemplated). Controller 250 is configured to select the contacts 248 through which energy is delivered and / or communication is established, e.g., depending upon the configuration of the instrument connected to generator 200. Suitable switching and / or other features within generator 200 may be provided to enable controller 250 to route the energy and / or communication signal(s) to the appropriate contact(s) 248. Alternatively, each contact 248 may include an energy pathway and / or a communication pathway connected thereto such that controller 250 can route the energy and / or communication signal(s) along the appropriate pathway(s) to the appropriate contact(s) 248.

[0079] Turning to FIGS. 8-10, in conjunction with FIGS. 1-3, plug 16 of instrument 10 (and, likewise, plug 316 of instrument 310 (FIG. 6) includes a plurality of contacts includingAttorney Docket: A0012501WO01 first, second, and third RF contacts 802, 804, 806 and a plurality of communication contacts 812, 814, 816, respectively. First and second RF contacts 802, 804 of plug 16 are connected to first and second electrical pathways 803, 805 defined from plug 16 through cable 14, housing 20, and shaft 12 to end effector assembly 70 to connect to first and second electrodes of end effector assembly 70, e.g., tissue contact surfaces 146, 148 of jaw members 72, 74. Third RF contact 806 of plug 16 is connected to third electrical pathway 807 defined from plug 16 through cable 14, housing 20, and shaft 12 to end effector assembly 70 to connect to the third electrode of end effector assembly 70, e.g., cutting element 149. Communication contacts 812, 814, 816 of plug 16 connect to electrical communication pathways 813, 815, 817 defined from plug 16 through cable 14 and into housing 20 to connect, for example, to activation assemblies 50, 60 and sensor 90 (FIG. 9) of housing 20, although connection to activation assemblies and / or sensors remote from housing 20 is also contemplated.

[0080] Referring also to FIG.7, when plug 16 is connected to a port 230 of generator 200, contacts 802, 804, 806, 812, 814, and 816 of plug 16 are electrically coupled to contacts 248 of port 230 of generator, thus enabling controller 250 of generator 200 to direct the delivery of current along electrical pathways 803, 805, and / or 807 and / or to communicate with instrument 10 along electrical communication pathways 813, 815, and / or 817.

[0081] With respect to instruments combining different RF current modalities, such as instrument 10 (FIG.1), parasitic capacitance between the different electrical pathways through the instrument may result in cross-coupled leakage current between one or more electrodes (or electrical pathway(s)) and the one or more other electrodes (or other electrical pathways), which may lead to unintended tissue effects, damage to instruments, and / or harm to the patient, surgeon, etc. Cross-coupled leakage current is of particular concern within instrument cables, where electrical pathways, e.g., wires, are in close proximity with one another for extended lengths, e.g., equal to or upwards of 1.5 meters, equal to or upwards of 3 meters, or equal to or upwards of 6 meters. Without any mitigations, the cross-coupled leakage current can exceed the limits for allowable cross-coupled leakage current as specified in International Electrotechnical Commission (IEC) Standard 60601-2-2:2017+AMD1:2023, published on February 21, 2023, rendering the instrument unworkable.

[0082] Continuing with reference to FIGS. 7-10 and to FIG. 9 in particular, in order to reduce or eliminate cross-coupled leakage current between the electrical pathways 803, 805, 807, instrument 10 includes a common mode choke assembly 900 disposed within housing 20. Common mode choke assembly 900 includes one or more common mode chokes 910 coupled along electrical pathways 803, 805 within housing 20. Each common mode choke 910, moreAttorney Docket: A0012501WO01 specifically, may be configured as an inductor with electrical pathways 803, 805 wound about a core. Each common mode choke 910 operates to allow equal and opposite currents through the windings of electrical pathways 803, 805 without encountering the inductance of the common mode choke 910 (due to the fact that the equal and opposite currents through the windings of electrical pathways 803, 805 produce canceling magnetic fields) and, thus, substantially no impedance is added to the electrical pathways 803, 805. As such, common mode choke 910 does not impede the sealing mode of operation wherein electrical pathways 803, 805 are utilized to energize tissue contacting surfaces 146, 148 of jaw members 72, 74 (see FIG.3) to different potentials to conduct electrosurgical energy therebetween and through tissue grasped between first and second jaw members 72, 74 (see FIG. 3). However, currents through the windings of electrical pathways 803, 805 that are not equal and opposite, e.g., currents in the same direction through the windings of electrical pathways 803, 805 or current along only one winding of a electrical pathway 803, 805, produce additive or net magnetic fields such that the currents through the winding(s) encounter the inductance of the common mode choke 910, thus introducing impedance to reduce or eliminate the not equal and opposite current along electrical pathway(s) 803, 805. Accordingly, while common mode choke assembly 900 does not impede function in the sealing mode of operation, cross-coupled leakage current resulting from parasitic capacitance, e.g., during a cutting mode of operation, which may present as not equal and opposite current along either or both electrical pathways 803, 805, is reduced or eliminated. Thus, during a cutting mode of operation, the return of current through either or both electrical pathways 803, 805 is reduced or eliminated.

[0083] Referring also to FIG. 11, in aspects, the common mode choke(s) 910 of common mode choke assembly 900 is a toroidal common mode choke having electrical pathways 803, 805 wound about a toroidal core 912. Although electrical pathways 803, 805 are shown wound about toroidal core 912 in a sectional configuration, it is also contemplated that electrical pathways 803, 805 may be wound in a bifilar manner, which may minimize leakage inductance.

[0084] With reference to FIG.12, in aspects, common mode choke assembly 900 includes a plurality of common mode chokes 920, 930 arranged in series. Utilizing plural common mode chokes 920, 930 in series provides a fault tolerance such that failure, e.g., as a result of a cracked inductor core, of one or more (but not all) of the common mode chokes 920, 930 still enables common mode choke assembly 900 to reduce or eliminate cross-coupled leakage current despite not all of the common mode chokes 920, 930 having their intended inductance.

[0085] Turning to FIG. 13, in aspects, each common mode choke 910 of common mode choke assembly 900 may define a parallel LC resonant topology, e.g., wherein each of theAttorney Docket: A0012501WO01 electrical pathways 803, 805 includes a capacitor 940 arranged in parallel with the windings of the common mode choke 910. This configuration helps reduce the heat produced by the common mode choke(s) 910 of common mode choke assembly 900 during energy dissipation and / or enables a reduction in the size and weight of the one or more common mode chokes 910 without sacrificing performance.

[0086] More specifically, with respect to heat generation, experimental results in accordance with this disclosure have shown that a common mode choke having a 39mH common mode inductance and 2 ohms series resistance dissipating 5 W of power in the housing of an electrosurgical instrument, e.g., housing 20 of instrument 10 (FIG. 1), may result in heating of the housing from an ambient temperature of about 23°C to about 47°C after 5 minutes and to about 80°C after 30 minutes. These temperatures render the housing unsafe to touch and, even prior to reaching unsafe temperatures, are uncomfortable for the surgeon. Further, in aspects where the housing is not directly contacted by a surgeon during use, e.g., with respect to robotic instruments, these temperatures are still troublesome in that they may result in damage to and / or performance degradation of the instrument 10 and / or surrounding instruments or components.

[0087] The parallel LC resonant topology of common mode choke assembly 900, e.g., wherein each of the electrical pathways 803, 805 includes a capacitor 940 arranged in parallel with the inductor core of the common mode choke 910, reduces the inductance required to achieve sufficient leakage current attenuation. For example, in accordance with the present disclosure, the parallel LC resonant topology of common mode choke assembly 900 may operate to dissipate power (e.g., about 0.5 W of power) for 5 minutes of use without increasing a temperature of the housing 20 of instrument 10 (FIG. 1) (or housing 320 of instrument 310 (FIG. 6)) by more than 5ºC in 5 minutes; in other aspects, without increasing the temperature by more than 4ºC in 5 minutes; and, in still other aspects, without increasing the temperature by more than 3ºC in 5 minutes.

[0088] The parallel LC resonant topology of common mode choke assembly 900 also enables a reduction in the size and weight of the common mode choke 910 without sacrificing performance, as noted above. Size reduction enables common mode choke assembly 900 to readily fit within housing 20 of instrument 10 (FIG.1) (or housing 320 of instrument 310 (FIG. 6)) without increasing the footprint of housing 20 (FIG. 1). Similarly, weight reduction helps maintain housing 20 of instrument 10 (FIG. 1) (or housing 320 of instrument 310 (FIG. 6)) at a sufficiently low weight so as not to increase surgeon fatigue (for handheld instruments), increase power requirements (for robotic instruments), and / or hamper maneuverability.Attorney Docket: A0012501WO01

[0089] Using the above-detailed example common mode choke having a 39mH common mode inductance and 2 ohms series resistance again as an example, such a common mode choke may have an inductor core defining dimensions of about 1 inch in diameter and about 0.40 inches in thickness and weighing about 2 ounces. For a given current and operating frequency, the overall volume of an inductor is roughly proportional to its inductance. Thus, if the inductance can be decreased, the volume can also be reduced. The parallel LC resonant topology of common mode choke assembly 900, e.g., wherein each of the electrical pathways 803, 805 includes a capacitor 940 arranged in parallel with the common mode choke 910, reduces the inductance required to achieve sufficient leakage current attenuation, as noted above; thus, the size and / or weight of the inductor core of the common mode choke 910 can be reduced without impacting the ability of the common mode choke 910 to achieve sufficient leakage current attenuation. More specifically, in aspects, the inductor core of the common mode choke assembly 900 in accordance with this disclosure may define a diameter (e.g., an outer diameter, in aspects where a toroid inductor core is utilized) equal to or less than about 0.60 inches; in other aspects, a diameter equal to or less than about 0.45 inches; and in still other aspects, a diameter equal to or less than about 0.30 inches. Additionally or alternatively, the inductor core of the common mode choke assembly 900 in accordance with this disclosure may define a thickness (e.g., a radial thickness, in aspects where a toroid inductor core is utilized) equal to or less than about 0.25 inches; in other aspects, a thickness equal to or less than about 0.20 inches; and in still other aspects, a thickness equal to or less than about 0.15 inches. Further, the inductor core of the common mode choke assembly 900 in accordance with this disclosure may define a weight equal to or less than about 1.00 ounces; in other aspects, a weight equal to or less than about 0.75 ounces; and in still other aspects, a weight equal to or less than about 0.50 ounces.

[0090] Referring to FIG.14, in conjunction with FIGS.7-10, as detailed above with respect to instrument 10 and generator 200 (FIG. 1), electrical pathway 807 of instrument 10 is configured to receive energy from one of the output pathways 247a, 247b of generator 200 for use in the cutting mode(s) of operation. In order to route energy through one of the output pathways 247a, 247b of generator 200 that is also used in the sealing mode of operating, capacitance is required in accordance with IEC Standard 60601-2-2, Clause 201.8.4.102, which provides that “[i]n order to minimize the possibility of neuromuscular stimulation, a capacitance shall be incorporated into the PATIENT circuit so that it is effectively in series with the ACTIVE ELECTRODE or one conductor of a BIPOLAR ACCESSORY. This capacitance shall not exceed 5 nF for MONOPOLAR PATIENT circuits and 50 nF forAttorney Docket: A0012501WO01 BIPOLAR PATIENT CIRCUITS. The DC resistance between ACTIVE and NEUTRAL ELECTRODE terminals, or between the terminals of a BIPOLAR output circuit, shall not beless than 2M .” More specifically a capacitance is incorporated into the cutting mode circuit,e.g., in series along electrical pathway 807 of instrument 10, in order to minimize the possibility of neuromuscular stimulation. The capacitance in the instrument in conjunction with the capacitance in the generator does not exceed 5 nF and, thus, complies with IEC Standard 60601-2-2, Clause 201.8.4.102.

[0091] In aspects, this capacitance to minimize the possibility of neuromuscular stimulation and satisfy IEC Standard 60601-2-2, Clause 201.8.4.102, thus enabling one of the output pathways 247a, 247b of generator 200 for use in delivering the energy from RF output stage 246 of generator 200 to electrical pathway 807 of instrument 10 in the cutting mode(s) includes one or more capacitors 1410, 1420 (and, in aspects, a plurality of capacitors 1410, 1420 arranged in series and, thus, also referred to as series capacitors) in series along electrical pathway 807. The one or more capacitors 1410, 1420 may be disposed within housing 20 of instrument 10 and / or within plug 16 of instrument 10. The one or more capacitors 1410, 1420 are thus disposed in the cutting mode circuit, wherein current is transmitted along electrical pathway 807 to cutting element 149 and to tissue in contact with cutting element 149 to cut tissue. The current is returned to generator 200 by a remote return device, e.g., return pad 110. Thus, capacitors 1410, 1420 are only present in the cutting circuit; capacitors 1410, 1420 are not used in the sealing circuit wherein current is communicated to / from generator 200 via bipolar electrical pathways 803, 805 of instrument 10.

[0092] Turning to FIG. 15, in aspects of this disclosure, two different electrical pathways 1807a, 1807b electrically connected to cutting element 149 and configured to couple cutting element 149 to generator 200 for supplying RF current to cutting element 149 may be provided. In such aspects, first and second electrical pathways 803, 805 as detailed above may also be provided to enable electrical connection of tissue contacting surfaces 146, 148 of jaw members 72, 74, respectively, to generator 200 for supplying RF current to tissue contacting surfaces 146, 148 to treat, e.g., seal, tissue grasped between tissue contacting surfaces 146, 148. The two different electrical pathways 1807a, 1807b are electrically isolated from one another (aside from their common connection to cutting element 149). The configurations detailed hereinbelow with reference to FIG. 15 may similarly include any of the aspects and features detailed above; thus, only differences are described in detail while similarities are summarily described or omitted entirely for purposes of brevity.Attorney Docket: A0012501WO01

[0093] In configurations where two different electrical pathways 1807a, 1807b, are provided, one of the electrical pathways, e.g., pathway 1807a, may be used for supplying current in a first configuration of end effector assembly 70 and / or for use of cutting element 149 in a first manner. Likewise, the other electrical pathway, e.g., pathway 1807b, may be used for supplying current in a second configuration of end effector assembly 70 and / or for use of cutting element 149 in a second manner. At least one plug, e.g., plug 16 (FIG.8), is configured to connect electrical pathways 1807a, 1807b of instrument 10 with output pathways 1247b, 1247c, respectively, of generator. For example, the two different electrical pathways 1807a, 1807b, in aspects, may connect to generator 200 via a common plug. Alternatively, and as another example, separates plugs may be provided for connecting each of the different electrical pathways 1807a, 1807b to generator 200.

[0094] In aspects, the first configuration of end effector assembly 70 corresponds to an open-jaw configuration wherein jaw members 72, 74 are more spaced-apart. This more spaced- apart position of jaw members 72, 74 may correspond to a position wherein jaw members 72, 74 are disposed in the spaced-apart position, not disposed in the approximated position, spaced- apart at a jaw angle defined between tissue contacting surfaces 146, 148 of greater than a threshold angle, where tissue is not grasped between jaw members 72, 74, wherein force on grasped tissue is below a threshold force, or in any other suitable manner. In such aspects, the second configuration of end effector assembly 70 corresponds to a closed-jaw configuration wherein jaw members 72, 74 are more approximated. This more approximated position of jaw members 72, 74 may correspond to a position wherein jaw members 72, 74 are disposed in the approximated position, not disposed in the spaced-apart position, spaced-apart at a jaw angle defined between tissue contacting surfaces 146, 148 of less than a threshold angle, grasping tissue therebetween, wherein force on grasped tissue is equal to or greater than a threshold force, or in any other suitable manner.

[0095] Use of cutting element 149 in the first manner may correspond to a configuration wherein current is conducted from cutting element 149 to tissue to cut the tissue and is returned to generator 200 via return pad 110 (or other suitable separate return device), while use of cutting element 149 in the second manner may correspond to a configuration wherein current is conducted from cutting element 149 to tissue to cut the tissue and is returned to generator 200 via either or both tissue contacting surfaces 146, 148 of jaw members 72, 74, respectively.

[0096] In order to enable use of cutting element 149 in different configurations of end effector assembly and / or in different manners, generator 200 may be configured to selectively output the energy along an appropriate electrical pathway 1807a, 1807b to cutting element 149,Attorney Docket: A0012501WO01 e.g., depending upon the configuration of end effector assembly 70 and / or the manner of use of cutting element 149. More specifically, generator 200 may include, in addition to first and second output pathways 247a, 247b connected to RF output stage 246 (as detailed above), a common output pathway 1247a connected to RF output stage 246, and first and second output pathways 1247b, 1247c selectively connectable to common output pathway 1247a via a switch 1247d. First and second output pathways 1247b, 1247c are, in turn, connected to contacts of port 230 of generator 200 (see FIG.1) for connection to corresponding contacts of plug 16 of instrument 10 (see FIG. 1). Thus, depending upon the configuration of end effector assembly 70, the manner of use of cutting element 149, and / or other input, e.g., user selection, switch 1247d is maintained or transitioned such that energy output along common output pathway 1247a is conducted along the appropriate output pathway 1247b, 1247c to the corresponding electrical pathway 1807a, 1807 of instrument 10 (FIG. 1), e.g., via corresponding contacts of plug 16 of instrument 10 and port 230 of generator 200 (see FIG.1). The configuration of end effector assembly 70, the manner of use of cutting element 149, and / or the user selection may be determined based on feedback from activation assemblies 50, 60 of instrument 10 (FIGS.1 and 2) and / or sensor 90 of instrument 10 (FIG.9), may be determined based on feedback from sensor circuitry 242 of generator 200 (FIG.7), and / or may be determined in any other suitable manner.

[0097] With additional reference to FIG. 16, a method 1600 of electrosurgery in accordance with this disclosure includes determining a use condition (also referred to as a mode of operation) at 1610. For example, it is determined whether the use condition is open dissection, as indicated at 1620, or in-jaw cutting, as indicated at 1630. The use condition may be determined as detailed above, e.g., based upon user input, sensor or other feedback, a determined configuration of the end effector assembly, etc. The open dissection use condition may correspond to the configuration wherein current is conducted from cutting element 149 to tissue to cut the tissue and is returned to generator 200 via return pad 110 and / or the open- jaw configuration of end effector assembly 70. The in-jaw cutting use condition may correspond to the configuration wherein current is conducted from cutting element 149 to tissue to cut the tissue and is returned to generator 200 via either or both tissue contacting surfaces 146, 148 of jaw members 72, 74, respectively, and / or the closed-jaw configuration of end effector assembly 70.

[0098] If the open dissection use condition is determined at 1620, the method proceeds to 1640 wherein current is conducted along first electrical pathway 1807a to cutting element 149 for transmission to tissue. Further, as indicated at 1660, current is returned to generator 200 toAttorney Docket: A0012501WO01 complete the circuit via return pad 110. On the other hand, if the in-jaw cutting use condition is determined at 1630, the method proceeds to 1650 wherein current is conducted along second electrical pathway 1807b to cutting element 149 for transmission to tissue. Further, as indicated at 1670, current is returned to generator 200 to complete the circuit via either or both tissue contacting surfaces 146, 148 of jaw members 72, 74.

[0099] Turning to FIG. 17, in conjunction with FIG. 15, as noted above, in some electrosurgical instruments and systems, cross-coupled leakage current between different electrical pathway(s) is a concern. As such, common mode choke assembly 900 (FIGS. 9-12) is provided to, in one mode of operation, inhibit the return of current through either or both electrical pathways 803, 805 while not impeding the mode of operation. Thus, in the open dissection use condition, for example, common mode choke assembly 900 (FIGS. 9-12) is effective at helping to ensure that current is returned to generator 200 via return pad 110 and not electrical pathways 803, 805. However, common mode choke assembly 900 (FIGS. 9-12) would not enable the in-jaw cutting use condition as common mode choke assembly 900 (FIGS. 9-12) inhibits the return path of the current in the in-jaw cutting use condition, e.g., through either or both electrical pathways 803, 805.

[0100] Accordingly, a common mode choke assembly 1700 is provided that enables use in both the open dissection use condition and the in-jaw cutting use condition while inhibiting cross-coupled leakage current. Common mode choke assembly 1700 includes one or more common mode chokes 1710 wherein each common mode choke 1710 includes a core 1712 having both electrical pathways 803, 805 as well as second electrical pathway 1807b wound about core 1712. Notably, first electrical pathway 1807a is electrically isolated from common mode choke assembly 1700, e.g., not wound about core 1712. Common mode choke assembly 1700, aside from having three electrical pathways 803, 805, 1807b wound about each core 1712 (rather than two), may otherwise be configured similar to and include any of the aspects and features of common mode choke assembly 900 (FIGS. 9-12), as detailed above, such as, for example, with respect to the number of common mode chokes, dimensions and / or weights of the common mode choke(s), thermal properties of the common mode chokes, locations of the common mode choke(s), etc. Common mode choke assembly 1700 may be disposed within the housing of the instrument, e.g., housing 20 of instrument 10 (FIG. 1), within the cable of the instrument, e.g., cable 14 (FIG. 1), within one or more plugs of the instrument, e.g., plug 16 (FIG. 1), within generator 200, and / or may extend across combinations thereof, e.g., wherein one common mode choke of common mode choke assembly 1700 is disposed at a first location and wherein another common mode choke of common mode choke assembly 1700 is disposedAttorney Docket: A0012501WO01 at a second, different location. Further, although electrical pathways 803, 805, 1807b are shown wound about core 1712 in a sectional configuration, it is also contemplated that electrical pathways 803, 805, 1807b may be wound in a bifilar manner, which may minimize leakage inductance.

[0101] Common mode choke assembly 1700 inhibits cross-coupled leakage current while enabling use in each of the open dissection (cutting) use condition and the in-jaw cutting use condition and without impeding the sealing mode of operation. More specifically, with respect to the open dissection (cutting) use condition, current is transmitted to cutting element 149 along first electrical pathway 1807a and current is returned to generator 200, after conduction through tissue, via return pad 110. With electrical pathways 803, 805, 1807b coupled to common mode choke assembly 1700, and with first electrical pathway 1807a electrically isolated from common mode choke assembly 1700, return of current along any of electrical pathways 803, 805, 1807b is inhibited because any such return current would not have equal and opposite current at common mode choke assembly 1700 (rather, as noted above, the supply of current is transmitted along electrically isolated pathway 1807a). Thus, cross-coupled leakage current is inhibited.

[0102] With respect to the in-jaw cutting use condition, current is transmitted to cutting element 149 along second electrical pathway 1807b and, thus, through common mode choke assembly 1700. Current is returned to generator 200, after conduction through tissue, via electrical pathway 803, electrical pathway 805, or both electrical pathways 803, 805 (in any proportion). As the input and return currents are provided through common mode choke assembly 1700, the current through common mode choke assembly 1700 is equal and opposite regardless of whether energy is returned via electrical pathway 803, electrical pathway 805, or a combination of electrical pathways 803, 805. Thus, current transmission through common mode choke assembly 1700 is not substantially impeded, allowing for in-jaw cutting.

[0103] Referring generally to FIGS.1-17, IEC Standard 60601-2-2, Clauses 201.3.208 and 201.3.229 define bipolar and monopolar as the “method of applying HF current to a PATIENT between two or more ACTIVE ELECTRODES without the need for a separately connected NEUTRAL ELECTRODE (or the need to use the PATIENT’S body capacitance to earth) in which an effect is intended in tissue near one or more ACTIVE ELECTRODES” and the “method of applying HF output current to a PATIENT via an ACTIVE ELECTRODE and returning via a separate PATIENT-connected NEUTRAL ELECTRODE (or via theAttorney Docket: A0012501WO01 PATIENT’S body capacitance to earth) in which an effect is intended only in tissue at or near the ACTIVE ELECTRODE,” respectively.

[0104] In aspects, according to the above-noted definitions, tissue treatment, e.g., tissue sealing, in accordance with the present disclosure wherein current is conducted between tissue contacting surfaces 146, 148 of jaw members 72, 74, respectively, to treat tissue grasped therebetween may be considered bipolar tissue sealing; tissue treatment, e.g., tissue cutting, wherein current is conducted between cutting element 149 and one or both of tissue contacting surfaces 146, 148 of jaw members 72, 74, respectively, to treat tissue in contact with cutting element 149 may be consider bipolar tissue cutting; and / or tissue treatment, e.g., tissue cutting, wherein current is conducted from cutting element 149 to return pad 110 to treat tissue in contact with cutting element 149 may be consider monopolar tissue cutting. However, the above-detailed current pathways between tissue contacting surfaces 146, 148, cutting element 149, and / or return pad 110 are not limited to the monopolar or bipolar classifications noted above.

[0105] Aspects of this disclosure may be further described by reference to the following numbered paragraphs:

[0106] 1. An electrosurgical instrument, comprising: a housing; a shaft extending distally from the housing; an end effector assembly coupled to a distal end of the shaft, the end effector assembly including first, second, and third electrodes; a plug including first, second, and third terminals configured to connect to an electrosurgical generator; a cable connecting the plug and the housing; first, second, and third electrical pathways extending from the end effector assembly through the shaft, the housing, and the cable to the plug, the first, second, and third electrical pathways electrically connecting the first, second, and third electrodes with the first, second, and third contacts, respectively; and a common mode choke assembly disposed within the housing, the common mode choke assembly coupled to the first and second electrical pathways such that leakage current along the first and second electrical pathways is inhibited when the third electrode is energized.

[0107] 2. The electrosurgical instrument according to paragraph 1, wherein the common mode choke assembly defines a parallel LC resonant topology.

[0108] 3. The electrosurgical instrument according to paragraph 1 or 2, wherein the common mode choke assembly includes a plurality of common mode chokes arranged in series.

[0109] 4. The electrosurgical instrument according to any one of paragraphs 1-3, wherein the common mode choke assembly is configured to dissipate power during 5 minutes of useAttorney Docket: A0012501WO01 without increasing a temperature of the housing by more than 5ºC, more than 10ºC, or more than 15ºC.

[0110] 5. The electrosurgical instrument according to any one of paragraphs 1-4, wherein an inductor core of a common mode choke of the common mode choke assembly at least one of: defines a diameter equal to or less than about 0.60 inches; defines a thickness equal to or less than 0.25 inches; or defines a weight equal to or less than 1.00 ounces.

[0111] 6. The electrosurgical instrument according to any one of paragraphs 1-5, wherein the end effector assembly includes first and second jaw members, at least one of the first or second jaw members movable relative to the other between a spaced-apart position and an approximated position for grasping tissue therebetween.

[0112] 7. The electrosurgical instrument according to paragraph 6, wherein the first electrode is disposed on the first jaw member, the second electrode is disposed on the second jaw member, and the third electrode is supported by one of the first or second jaw members.

[0113] 8. The electrosurgical instrument according to paragraph 7, wherein the first and second electrodes are configured to conduct current therebetween and through tissue grasped between the first and second jaw members to seal the grasped tissue, and wherein the third electrode is configured to conduct current to tissue in contact with the third electrode to cut the tissue in contact with the third electrode.

[0114] 9. The electrosurgical instrument according to any one of paragraphs 1-8, wherein the housing includes a handle configured to be grasped by a surgeon and at least one manual actuator configured to be actuated by a surgeon.

[0115] 10. The electrosurgical instrument according to any one of paragraphs 1-8, wherein the housing is configured to connect to a robotic arm of a surgical robotic system and includes at least one input coupler configured to be actuated by the surgical robotic system.

[0116] 11. An electrosurgical instrument, comprising: a housing; a shaft extending distally from the housing; an end effector assembly coupled to a distal end of the shaft, the end effector assembly including first, second, and third electrodes; a plug including first, second, and third contacts configured to connect to an electrosurgical generator having first and second ports; a cable connecting the plug and the housing; and first, second, and third electrical pathways extending from the end effector assembly through the shaft, the housing, and the cable to the plug, the first, second, and third electrical pathways electrically connecting the first, second, and third electrodes with the first, second, and third contacts, respectively, wherein, in a first mode of operation, the first and second instrument terminals are connected to the first and second ports, respectively, for conducting energy through tissue disposed between the first andAttorney Docket: A0012501WO01 second electrodes to treat the tissue disposed between the first and second electrodes, wherein, in a second mode of operation, the third contact is connected to one of the first or second ports for conducting current from the third electrode to tissue in contact with the third electrode to treat the tissue in contact with the third electrode, and wherein the third electrical pathway incorporates a capacitance to minimize the possibility of neuromuscular stimulation.

[0117] 12. The electrosurgical instrument according to paragraph 11, wherein the third electrical pathway includes at least one series capacitor.

[0118] 13. The electrosurgical instrument according to paragraph 12, wherein the at least one series capacitor is disposed in the housing.

[0119] 14. The electrosurgical instrument according to paragraph 12, wherein the at least one series capacitor is disposed in the plug.

[0120] 15. The electrosurgical instrument according to any one of paragraphs 11-14, wherein the third electrical pathway includes a plurality of series capacitors.

[0121] 16. The electrosurgical instrument according to any one of paragraphs 11-15, wherein the plug further includes at least one signal terminal, the at least one signal terminal configured to communicate a signal to the electrosurgical generator to supply current in the first mode of operation or the second mode of operation.

[0122] 17. The electrosurgical instrument according to any one of paragraphs 11-16, wherein the end effector assembly includes first and second jaw members, at least one of the first or second jaw members movable relative to the other between a spaced-apart position and an approximated position for grasping tissue therebetween.

[0123] 18. The electrosurgical instrument according to paragraph 17, wherein the first electrode is disposed on the first jaw member, the second electrode is disposed on the second jaw member, and the third electrode is supported by one of the first or second jaw members.

[0124] 19. The electrosurgical instrument according to any one of paragraphs 11-18, wherein the housing includes a handle configured to be grasped by a surgeon and at least one manual actuator configured to be actuated by a surgeon.

[0125] 20. The electrosurgical instrument according to any one of paragraphs 11-18, wherein the housing is configured to connect to a robotic arm of a surgical robotic system and includes at least one input coupler configured to be actuated by the surgical robotic system.

[0126] 21. An electrosurgical system, comprising: an end effector assembly including an electrode, the electrode energizable in each of a first manner and a second manner; and first and second electrical pathways configured to electrically connect the electrode to an electrosurgical generator, the first and second electrical pathways electrically isolated from oneAttorney Docket: A0012501WO01 another, wherein, energizing the electrode in the first manner includes conducting current along the first electrical pathway to the electrode for transmitting the current to tissue, and wherein energizing the electrode in the second manner includes conducting current along the second electrical pathway to the electrode for transmitting the current to tissue.

[0127] 22. The electrosurgical system according to paragraph 21, wherein: when the electrode is energized in the first manner, current is transmitted from the electrode through tissue to at least one other electrode of the end effector assembly, and when the electrode is energized in the second manner, current is transmitted from the electrode through tissue to at least one other electrode remote from the end effector assembly.

[0128] 23. The electrosurgical system according to paragraph 22, wherein at least one other electrical pathway is configured to connect the at least one other electrode of the end effector assembly to an electrosurgical generator, and wherein a common mode choke assembly is coupled to both the second electrical pathway and the at least one other electrical pathway.

[0129] 24. The electrosurgical system according to paragraph 23, wherein the at least one other electrode of the end effector assembly includes first and second other electrodes, wherein the at least one other electrical pathway includes third and fourth electrical pathways configured to connect the first and second other electrodes, respectively, to an electrosurgical generator, and wherein the common mode choke assembly is coupled to each of the second, third, and fourth electrical pathways.

[0130] 25. The electrosurgical system according to paragraph 24, wherein the common mode choke assembly is electrically isolated from the first electrical pathway.

[0131] 26. The electrosurgical system according to any one of paragraphs 21-25, wherein the end effector assembly includes first and second jaw members, at least one of the first or second jaw members movable relative to the other between a spaced-apart position and an approximated position for grasping tissue therebetween.

[0132] 27. The electrosurgical system according to paragraph 26, wherein: the electrode is energized in the first manner when the first and second jaw members are disposed in the spaced- apart position, and the electrode is energized in the second manner when the first and second jaw members are disposed in the approximated position.

[0133] 28. The electrosurgical system according to any one of paragraphs 21-27, further comprising: at least one plug including first and second contacts configured to connect to an electrosurgical generator, wherein the first and second electrical pathways connect to the first and second contacts, respectively.Attorney Docket: A0012501WO01

[0134] 29. The electrosurgical system according to paragraph 28, further comprising at least one feedback device, wherein the at least one plug further includes a communication contact, and wherein information indicative of whether to energize the electrode in the first manner or the second manner is communicated from the at least one feedback device to an electrosurgical generator via the communication contact.

[0135] 30. The electrosurgical system according to paragraph 29, further comprising the electrosurgical generator, wherein: the electrosurgical generator is configured to output current to the first contact when it is determined that the electrode is to be energized in the first manner, and wherein the electrosurgical generator is configured to output current to the second contact when it is determined that the electrode is to be energized in the second manner.

[0136] While several aspects of this disclosure have been shown in the drawings, it is not intended that this 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 aspects. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

Attorney Docket: A0012501WO01 WHAT IS CLAIMED IS:

1. An electrosurgical instrument (10), comprising: a housing (20); a shaft (12) extending distally from the housing; an end effector assembly (70) coupled to a distal end of the shaft, the end effector assembly including first (146), second (148), and third (149) electrodes; a plug (16) including first (802), second (804), and third (806) contacts configured to connect to an electrosurgical generator (200); a cable (14) connecting the plug and the housing; first (803), second (805), and third (807) electrical pathways extending from the end effector assembly through the shaft, the housing, and the cable to the plug, the first, second, and third electrical pathways electrically connecting the first, second, and third electrodes with the first, second, and third contacts, respectively; and a common mode choke assembly (900) disposed within the housing, the common mode choke assembly coupled to the first and second electrical pathways such that leakage current along the first and second electrical pathways is inhibited when the third electrode is energized.

2. The electrosurgical instrument according to claim 1, wherein the common mode choke assembly defines a parallel LC resonant topology.

3. The electrosurgical instrument according to claim 1 or 2, wherein the common mode choke assembly includes a plurality of common mode chokes (910) arranged in series.

4. The electrosurgical instrument according to any one of claims 1-3, wherein the common mode choke assembly is configured to dissipate power during 5 minutes of use without increasing a temperature of the housing by more than 5ºC.

5. The electrosurgical instrument according to any one of claims 1-4, wherein an inductor core of a common mode choke of the common mode choke assembly at least one of: defines a diameter equal to or less than about 0.60 inches; defines a thickness equal to or less than 0.25 inches; or defines a weight equal to or less than 1.00 ounces.

6. An electrosurgical instrument (10), comprising:Attorney Docket: A0012501WO01 a housing (20); a shaft (12) extending distally from the housing; an end effector assembly (70) coupled to a distal end of the shaft, the end effector assembly including first (146), second (148), and third (149) electrodes; a plug (16) including first (802), second (804), and third (806) contacts configured to connect to an electrosurgical generator (200) having first (230) and second (230) ports ; a cable (14) connecting the plug and the housing; and first (803), second (805), and third (807) electrical pathways extending from the end effector assembly through the shaft, the housing, and the cable to the plug, the first, second, and third electrical pathways electrically connecting the first, second, and third electrodes with the first, second, and third contacts , respectively, wherein, in a first mode of operation, the first and second contacts are connected to the first and second ports, respectively, for conducting current between the first and second electrodes and through tissue disposed therebetween to treat the tissue disposed between the first and second electrodes, wherein, in a second mode of operation, the third contact is connected to one of the first or second ports for conducting current from the third electrode to tissue in contact with the third electrode to treat the tissue in contact with the third electrode, and wherein the third electrical pathway incorporates a series capacitance to minimize a possibility of neuromuscular stimulation.

7. The electrosurgical instrument according to claim 6, wherein the third electrical pathway includes at least one series capacitor (1410).

8. The electrosurgical instrument according to claim 7, wherein the at least one series capacitor is disposed in the housing.

9. The electrosurgical instrument according to claim 7, wherein the at least one series capacitor is disposed in the plug.

10. The electrosurgical instrument according to any one of claims 6-9, wherein the plug further includes at least one signal terminal, the at least one signal terminal configured to communicate a signal to the electrosurgical generator to supply current in the first mode of operation or the second mode of operation.Attorney Docket: A0012501WO01 11. An electrosurgical system (2), comprising: an end effector assembly (70) including an electrode (149) energizable in each of a first manner and a second manner; and first (1807a) and second (1807b) electrical pathways configured to electrically connect the electrode to an electrosurgical generator, the first and second electrical pathways electrically isolated from one another, wherein, energizing the electrode in the first manner includes conducting current along the first electrical pathway to the electrode for transmitting the current to tissue, and wherein, energizing the electrode in the second manner includes conducting current conducted along the second electrical pathway to the electrode for transmitting the current to tissue.

12. The electrosurgical system according to claim 11, wherein: when the electrode is energized in the first manner, the current is transmitted from the electrode through tissue to at least one other electrode of the end effector assembly, and when the electrode is energized in the second manner, the current is transmitted from the electrode through tissue to at least one other electrode remote from the end effector assembly.

13. The electrosurgical system according to claim 12, wherein at least one other electrical pathway is configured to connect the at least one other electrode of the end effector assembly to an electrosurgical generator (200), and wherein a common mode choke assembly (900) is coupled to both the second electrical pathway and the at least one other electrical pathway.

14. The electrosurgical system according to claim 13, wherein the at least one other electrode of the end effector assembly includes first and second other electrodes, wherein the at least one other electrical pathway includes third and fourth electrical pathways configured to connect the first and second other electrodes, respectively, to an electrosurgical generator, and wherein the common mode choke assembly is coupled to each of the second, third, and fourth electrical pathways.

15. The electrosurgical system according to claim 14, wherein the common mode choke assembly is electrically isolated from the first electrical pathway.

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