Internal-shield cable for bimodal surgical tool

Abstract

The technology relates to a cable for a multimodal surgical tool having jaw electrodes that use a bipolar energy modality and a cutting electrode that uses a monopolar energy modality. The cable includes a first wire connected to a first jaw electrode, a second wire connected to a second jaw electrode, and a third wire connected to the cutting electrode. The cable includes a conductive shield between the third wire and the first and second wires to mitigate the effects of parasitic capacitance between the third wire and the first and second wires when the third wire is energized. The conductive shield encloses either the third wire or the first and second wires, along with a drain wire that is in contact with the conductive shield.

Description

Attorney Docket No. A0012215W001INTERNAL-SHIELD CABLE FOR BIMODAL SURGICAL TOOLCROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 702,721, filed October 3, 2024, which is incorporated herein by reference in its entirety.BACKGROUND

[0002] Surgical tools, such as vessel sealing and / or cutting tools, may use monopolar or bipolar energy modalities. For a monopolar energy modality, such as may be used in a cutting device, energy supplied by an electrosurgical generator (ESG) is delivered to an active electrode (e.g., a cutting electrode) and returned to the generator via a remote neutral electrode that is placed on the patient’s body, away from the active electrode. The energy travels through the patient’s body to reach the neutral electrode. For a bipolar energy modality, such as may be used for a vessel sealing tool, energy supplied by the ESG is delivered to a first electrode of the tool and returned to the generator via a second electrode of the tool that is in close proximity to the first electrode.

[0003] It is with respect to this general technical environment that aspects of the present technology disclosed herein have been contemplated. Furthermore, although a general environment is discussed, it should be understood that the examples described herein should not be limited to the general environment identified herein.SUMMARY

[0004] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter.

[0005] In an aspect, the technology relates to a cable used to supply energy from an electrosurgical generator to a bimodal surgical tool that can operate in a bipolar energy modality using two electrodes (e.g., opposing jaws of a sealing tool) or operate in a monopolar energy modality using a single electrode (e.g., a cutting electrode). The use of both energy modalities within a single tool that is connected to a generator with a single supply cable may lead to challenges related to parasitic capacitance within the cable. Because the cable may be relativelyAttorney Docket No. A0012215W001 long (e.g., 5-10 feet) and the supply wires may run alongside each other for some distance, there may be significant parasitic capacitance between the monopolar wire (the wire used to supply current to the monopolar electrode) and the bipolar wires (the wires used to supply and return current to / from the bipolar electrodes). The cross-coupled current resulting from the parasitic capacitance among these wires may be especially large when the generator directs energy to the monopolar electrode and not to the bipolar electrodes (e.g., at the jaws). Cross-coupled or leakage current may be generated in the bipolar wires due to parasitic capacitance between the monopolar wires and the bipolar wires, and the cross-coupled or leakage current may cause unintended tissue effect at the bipolar electrodes.

[0006] Thus, as described herein, a cable supplying a bimodal surgical tool includes a conductive shield that is designed to mitigate the effects of parasitic capacitance between the various wires for supplying energy to the electrodes and avoid unintended tissue effect at the bipolar electrodes.

[0007] The cable includes first and second bipolar wires for supplying and returning current to / from the bipolar electrodes (one wire for each electrode / jaw) and a monopolar wire for supplying current to the monopolar electrode. Each wire may include an insulating sheath and be connected, via a plug, to an electrosurgical generator (ESG) on one end and to the respective electrodes on the other end. To mitigate the effects of parasitic capacitance within the cable that arises between the monopolar wire and the first and second bipolar wires when the monopolar wire is energized (e.g., receiving current / voltage from the ESG), the cable includes a conductive shield that encloses either the monopolar wire or the first and second bipolar wires. The parasitic capacitance then causes cross-coupled or leakage current in the conductive shield rather than in the bipolar wires. The conductive shield is coupled with a drain wire of the cable to return the cross-coupled or leakage current generated in the shield (e.g., current that arises due to parasitic capacitance between the monopolar wire and the shield) back to the generator. The use of the shield thereby substantially reduces any cross-coupled or leakage current caused by parasitic capacitance between the monopolar wire and the bipolar wires, thereby reducing the likelihood of overheating the jaws and potentially burning the patient when the cutter is active and the jaws are inactive and separated.Attorney Docket No. A0012215W001

[0008] In one aspect, the present disclosure provides a medical device. The medical device includes a multimodal surgical tool configured to be coupled with an electrosurgical generator via a cable connected to the tool, the tool including: forceps that include a first jaw electrode connected to a first wire of the cable and a second jaw electrode connected to a second wire of the cable; and

[0009] a cutting electrode configured to cut tissue, where the cutting electrode is connected to a third wire of the cable. The cable includes a conductive shield between the third wire and the first and second wires, where the conductive shield extending along a longitudinal axis of the cable.

[0010] In an aspect, the conductive shield encloses at least a portion of a longitudinal length of the third wire, and the first wire and the second wire are outside the conductive shield.

[0011] In an aspect, the conductive shield encloses at least a portion of a longitudinal length of the first wire and at least a portion of a longitudinal length of the second wire, and the third wire is outside of the conductive shield.

[0012] In an aspect, the conductive shield is cylindrical.

[0013] In an aspect, the conductive shield encloses at least a portion of a drain wire that is configured to return current to the generator from the conductive shield.

[0014] In an aspect, the conductive shield is in contact with the drain wire.

[0015] In an aspect, the tool includes one or more switches configured to select either activation of the first jaw electrode or activation of the cutting electrode.

[0016] In an aspect, the conductive shield further encloses one or more switch wires that are connected to the one or more switches.

[0017] In an aspect, the cable includes a non-conductive jacket around the first wire, the second wire, the third wire, and the conductive shield.

[0018] In an aspect, the conductive shield includes a conductive mesh, a conductive braid, or a conductive foil.Attorney Docket No. A0012215W001

[0019] In an aspect, the cable includes a plug configured to be connected, via a plurality of pins of the plug, to an electrical interface of the electrosurgical generator, the plug having a first pin connected to the first wire, a second pin connected to the second wire, and a third pin connected to the third wire.

[0020] In another aspect, the disclosure provides a medical device. The medical device includes: a first electrode; a second electrode; a third electrode; a cable that includes: a first wire connected to the first electrode; a second wire connected to the second electrode; a third wire connected to the third electrode; and a conductive shield between the third wire and the first and second wires, where the conductive shield extends along a longitudinal axis of the cable.

[0021] In an aspect, the conductive shield encloses at least a portion of a longitudinal length of the third wire, and the first wire and the second wire are outside the conductive shield.

[0022] In an aspect, the conductive shield encloses at least a portion of a longitudinal length of the first wire and at least a portion of a longitudinal length of the second wire, and the third wire is outside of the conductive shield.

[0023] In an aspect, the cable includes a drain wire that is in contact with the conductive shield.

[0024] In an aspect, the cable includes a fourth wire connected to a switch of the medical device, where the switch is configured to select the first electrode or the third electrode for activation.

[0025] In an aspect, the conductive shield encloses at least a portion of a longitudinal length of the fourth wire.

[0026] In an aspect, the fourth wire is outside the conductive shield.

[0027] In an aspect, the fourth wire is selectively coupled with the drain wire via one or more resistors.

[0028] In an aspect, the first wire is enclosed in a non-conductive jacket.

[0029] The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniquesAttorney Docket No. A0012215W001 described in this disclosure will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The following drawing figures, which form a part of this application, are illustrative of aspects of systems and methods described below and are not meant to limit the scope of the disclosure in any manner, which scope shall be based on the claims.

[0031] FIG. 1 depicts an example surgical system in accordance with aspects of the current disclosure.

[0032] FIG. 2 depicts example electrical connections of a surgical system in accordance with aspects of the current disclosure.

[0033] FIGs. 3A-3B depict example current paths within a cable in accordance with aspects of the current disclosure.

[0034] FIG. 4 depicts an example cross section of a cable for a bimodal surgical tool in accordance with aspects of the current disclosure.

[0035] FIG. 5 depicts an example cross section of a cable for a bimodal surgical tool in accordance with aspects of the current disclosure.

[0036] FIG. 6 depicts a schematic illustration of a surgical robotic system in accordance with this disclosure.DETAILED DESCRIPTION

[0037] Surgical tools typically use either a monopolar energy pathway or a bipolar energy pathway. For monopolar energy, current or voltage is supplied by an ESGto a single electrode at the end effector and returned to the ESG via a remote neutral pad (e.g., a conductive pad that is placed on the patient’s body away from the electrode and connected to the ESG). The current travels from the end-effector electrode to the neutral electrode through the patient’s body. Monopolar energy may be used in cutting or ablation tools, for example.Attorney Docket No. A0012215W001

[0038] For bipolar energy, current is supplied to a first end-effector electrode and returned through a second end-effector electrode that is in close proximity to the first electrode. The first end-effector electrode may be at a different voltage potential relative to the second end-effector electrode. Current travels between the two electrodes and is returned to the ESG without a need for a remote neutral electrode. Bipolar energy may be used in, for example, tissue sealing tools that have two jaws (electrodes) that are brought into close proximity during use, for example.

[0039] In some cases, it may be desirable to have a single surgical instrument (e.g., with a single handle or housing and a single supply cable connected between the ESG and the instrument) that includes both a bipolar, dual-electrode tool and a monopolar, single-electrode tool. Challenges may arise, however, with parasitic capacitance (and resulting cross-coupled or leakage current) between the wires supplying current to the different tools. Because the cable is relatively long (e.g., 5-10 feet) and the supply wires run alongside each other for some distance, there may be significant parasitic capacitance between the wire for the monopolar current supply and the wires for the bipolar current supply when the monopolar tool is in use. The parasitic capacitance may cause cross-coupled or leakage current in the wires for the bipolar tool, which may in turn lead the electrodes of the bipolar tool to overheat when they are not in use — particularly when they are separated from each other.

[0040] As described herein, a cable for such a bimodal surgical tool may therefore include a conductive shield around either the wire supplying the monopolar tool or around the two wires supplying the bimodal tool. The conductive shield is coupled with a drain wire in the cable to provide a return path for current that arises in the shield due to the parasitic capacitance and reduce or eliminate cross-coupled or leakage current in the bipolar supply wires.

[0041] Additional details regarding a cable for a bimodal surgical tool are described with reference to FIGs. 1-5.

[0042] FIG. 1 depicts a surgical system 100 including an electrosurgical generator (ESG) 102 and bimodal surgical tool 109. The bimodal surgical tool 109 may be connected to the ESG 102 via a first cable 104. The bimodal surgical tool includes a housing 108 and an elongated shaft 115 that connects the housing 108 to an end effector 110. The surgical tool includes wires within the shaft 115 for providing current to electrodes at the end effector 110.Attorney Docket No. A0012215W001

[0043] The end effector 110 includes a first jaw electrode 112 and a second jaw electrode 114 that may be used for grasping and sealing tissue. The first jaw electrode 112 and second jaw electrode 114 are operable to move relative to each other such that they may be spaced apart or brought together. The first jaw electrode 112 and second jaw electrode 114 operate using a bipolar energy modality in which current is supplied by the ESG 102 to one of the jaw electrodes and returned to the ESG 102 via the other jaw electrode when the jaws are in close proximity (e.g., touching or nearly touching each other, such as when grasping tissue).

[0044] The end effector 110 further includes a cutter electrode 116 that is configured to cut tissue when the electrode is activated. The cutter electrode 116 operates in a monopolar energy modality in which the current supplied by the ESG 102 to the cutter electrode 116 travels through the patient’s body to a neutral electrode 118. The current is returned to the ESG 102 via the neutral electrode 118, which may be connected to the generator via a second cable 120.

[0045] FIG. 2 depicts electrical connections of a surgical system 200 that includes an ESG 102, a plug 202 connected to the ESG 102, a first cable 104 connected to (or including) the plug 202, and a bimodal surgical tool that includes a housing 108 and an end effector 110, as described with reference to FIG. 1. The plug 202 includes multiple pins 204, some or all of which are connected to corresponding wires in the first cable 104 to couple the wires in the first cable 104 to the ESG 102. The ESG 102 supplies current to one or more pins 204 of the plug 202 to supply current to the electrodes of the end effector 110.

[0046] The first jaw electrode 112 of the end effector 110 is connected to the ESG 102 via a first electrical path that includes a first wire 220 in the first cable 104. The first wire 220 may be enclosed by a non-conductive jacket. The second jaw electrode 114 is connected to the ESG 102 via a second electrical path that includes a second wire 222 in the first cable. The second wire 222 may be enclosed by a non-conductive jacket. The cutter electrode 116 is connected to the ESG 102 via a third electrical path that includes a third wire 224 in the first cable 104. The third wire is enclosed by a non-conductive jacket. The first wire 220 is connected to a first pin of the plug 202, the second wire that is connected to a second pin of the plug 202, and the third wire is connected to a third pin of the plug 202. As discussed in more detail with reference to FIGs. 3A- 3B and 4, the first cable 104 includes a conductive shield (not shown) around either the third wireAttorney Docket No. A0012215W001224 or the first wire 220 and second wire 222 to reduce or eliminate cross-coupled or leakage current generated in the first wire 220 and second wire 222 due to parasitic capacitance between the first wire and the second and third wires when the first wire is supplying current to the cutter electrode 116.

[0047] In operation, a clinician sets one or more physical switches on the housing 108 to select an electrode to activate (e.g., to activate either a jaw electrode or the cutter electrode). The housing 108 encloses electronic switches 206a-c and resistors (R1-R6) that are coupled to the physical switches and used to provide inputs to the ESG 102 (e.g., to control the operation of ESG 102). Depending on which switches 206 are closed, the ESG 102 detects different resistances of the switching circuitry. The switching circuitry is connected to the plug 202 via switch wires 216 and 218 of the first cable 104 and via a drain wire 214.

[0048] The drain wire 214 is configured to return current to the ESG 102 from the conductive shield. That is, the conductive shield is in contact with the drain wire 214 to transfer cross-coupled or leakage current generated in the conductive shield via parasitic capacitance from the first wire, second wire, and / or third wire back to the ESG 102.

[0049] As previously mentioned, when the ESG 102 supplies a current or voltage to the cutter electrode 116, parasitic capacitance between the third wire 224 in the cable and the first wire 220 and second wire 222 may result in cross-coupled or leakage current in the first wire 220 and second wire 222. This cross-coupled or leakage current may increase the temperature of the first jaw electrode 112 and / or second jaw electrode 114 and cause burns to the patient if the jaw electrodes make contact with the patient. Thus, as described herein, the first cable 104 includes a conductive shield around the first wire 220 and second wire 222 wires and / or a shield around the third wire 224 to reduce or eliminate cross-coupled or leakage current between these wires.

[0050] FIGs. 3A-3B depict current paths within a cable that lacks a conductive shield around the third (cutter) wire (FIG. 3A) or includes a conductive shield around the third wire (FIG. 3B). In FIG. 3 A, cross-coupled or leakage current is generated in the first wire and second wire in the cable 104 (e.g., the wires connected to the jaw electrodes) when the third wire is supplying energy to the monopolar electrode, due to parasitic capacitance (represented by capacitors Cl and C2) in the cable between the third wire and the first and second wires.Attorney Docket No. A0012215W001

[0051] In FIG. 3B, a conductive shield in the cable encloses the third wire and provides a path for cross-coupled or leakage current to return to the generator (via a drain wire connected to the conductive shield). In this case, the parasitic capacitance arises between the third wire and the conductive shield (represented by capacitor Cl) and not between the third wire and the first and second wires.

[0052] FIG. 4 depicts an example cross section of a cable 400 for a bimodal surgical tool. In FIG. 4, black-filled circles represent conductive wires, which are typically enclosed by non- conductive sheathing (shown as patterned areas).

[0053] The cable 400 includes an outer non-conductive jacket 402 that encloses a first wire 404 (e.g., a wire connected to a first electrode, such as a cutter electrode), a second wire 406 (e.g., a wire connected to a second electrode, such as a first jaw electrode), and a third wire 408 (e.g., a wire connected to a third electrode, such as a second jaw electrode). The cable 400 includes a fourth wire 412 and fifth wire 414 that are connected to switches of the surgical tool (e.g., to control activation of the tool and positioning of the jaws). The cable 400 includes a drain wire 410 that is in contact with a conductive shield 416. The conductive shield 416 encloses the second wire 406, the third wire 408, the fourth wire 412, the fifth wire 414, and the drain wire 410. The first wire is outside of the conductive shield 416. In other examples, the conductive shield may enclose the second wire 406, the third wire 408, and the drain wire 410, but not the switch wires (the fourth wire 412 and fifth wire 414). The cable 400 further includes two fillers 418 that help maintain the cylindrical shape of the cable 400 but provide no electrical connectivity. The conductive shield 416 is formed of a conductive material and may be in the form of a wire braid, a metallic mesh, or a conductive foil, for example. The conductive shield 416 may be formed from copper, aluminum, or other conductive material.

[0054] FIG. 5 depicts an example cross section of another cable 500 for a bimodal surgical tool. In the example of FIG. 5, the conductive shield 416 encloses the first wire 404 and the drain wire 410 but does not enclose (e.g., excludes) the second wire 406 and third wire 408. Thus, the second wire 406 and third wire 408 are outside the conductive shield 416. This arrangement, like the arrangement depicted in FIG. 4, prevents or reduces cross-coupled or leakage current in the second wire 406 and third wire 408 arising from parasitic capacitance with the first wire 404.Attorney Docket No. A0012215W001

[0055] A person of skill in the art will appreciate that the example cables shown in FIGs. 4 and 5 are intended as illustrative examples and the specific arrangement of wires and fillers inside the cable can vary.

[0056] FIG. 6 depicts a robotic surgical system 1000 provided in accordance with the present disclosure. 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.

[0057] 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, preoperative data from patient 1013 and / or anatomical atlases.

[0058] 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 110 (FIG. 1), 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 1004Attorney Docket No. A0012215W001 may also be configured in such a way that it regulates the movement of robot arms 1002, 1003 and / or of the motors.

[0059] It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings.

[0060] The following examples are illustrative of the techniques described herein.

[0061] Example 1. A medical device, comprising: a multimodal surgical tool configured to be coupled with an electrosurgical generator via a cable connected to the tool, the tool comprising: forceps comprising a first jaw electrode connected to a first wire of the cable and a second jaw electrode connected to a second wire of the cable; and a cutting electrode configured to cut tissue, wherein the cutting electrode is connected to a third wire of the cable, wherein the cable comprises a conductive shield between the third wire and the first and second wires, the conductive shield extending along a longitudinal axis of the cable.

[0062] Example 2. The medical device of example 1, wherein the conductive shield encloses at least a portion of a longitudinal length of the third wire, and wherein the first wire and the second wire are outside the conductive shield.

[0063] Example s. The medical device of example 1, wherein the conductive shield encloses at least a portion of a longitudinal length of the first wire and at least a portion of a longitudinal length of the second wire, and wherein the third wire is outside of the conductive shield.

[0064] Example 4. The medical device of example 1, wherein the conductive shield is cylindical.

[0065] Example 5. The medical device of example 1, wherein the conductive shield encloses at least a portion of a drain wire that is configured to return current to the generator from the conductive shield.

[0066] Example 6. The medical device of example 5, wherein the conductive shield is in contact with the drain wire.Attorney Docket No. A0012215W001

[0067] Example 7. The medical device of example 1 , wherein the tool includes one or more switches configured to select either activation of the first jaw electrode or activation of the cutting electrode.

[0068] Example 8. The medical device of example 7, wherein the conductive shield further encloses one or more switch wires that are connected to the one or more switches.

[0069] Example 9. The medical device of example 1, wherein the cable comprises a non-conductive jacket around the first wire, the second wire, the third wire, and the conductive shield.

[0070] Example 10. The medical device of example 1, wherein the conductive shield comprises a conductive mesh, a conductive braid, or a conductive foil.

[0071] Example 11. The medical device of example 1 , wherein the cable includes a plug configured to be connected, via a plurality of pins of the plug, to an electrical interface of the electrosurgical generator, the plug having a first pin connected to the first wire, a second pin connected to the second wire, and a third pin connected to the third wire.

[0072] Example 12. A medical device, comprising: a first electrode; a second electrode; a third electrode; a cable comprising; a first wire connected to the first electrode; a second wire connected to the second electrode; a third wire connected to the third electrode; a conductive shield between the third wire and the first and second wires, the conductive shield extending along a longitudinal axis of the cable.

[0073] Example 13. The medical device of example 12, wherein the conductive shield encloses at least a portion of a longitudinal length of the third wire, and wherein the first wire and the second wire are outside the conductive shield.

[0074] Example 14. The medical device of example 12, wherein the conductive shield encloses at least a portion of a longitudinal length of the first wire and at least a portion of a longitudinal length of the second wire, and wherein the third wire is outside of the conductive shield.Attorney Docket No. A0012215W001

[0075] Example 15. The medical device of example 12, wherein the cable comprises a drain wire that is in contact with the conductive shield.

[0076] Example 16. The medical device of example 12, wherein the cable comprises a fourth wire connected to a switch of the medical device, wherein the switch is configured to select the first electrode or the third electrode for activation.

[0077] Example 17. The medical device of example 16, wherein the conductive shield encloses at least a portion of a longitudinal length of the fourth wire.

[0078] Example 18. The medical device of example 16, wherein the fourth wire is outside the conductive shield.

[0079] Example 19. The medical device of example 16, wherein the fourth wire is selectively coupled with the drain wire via one or more resistors.

[0080] Example 20. The medical device of example 12, wherein the first wire is enclosed in a non-conductive jacket.

Claims

Attorney Docket No. A0012215W001CLAIMSWhat is claimed is:

1. A medical device, comprising: a multimodal surgical tool (109) configured to be coupled with an electrosurgical generator (102) via a cable (104) connected to the tool, the tool comprising: forceps comprising a first jaw electrode (112) connected to a first wire (220) of the cable and a second jaw electrode (114) connected to a second wire (222) of the cable; and a cutting electrode (116) configured to cut tissue, wherein the cutting electrode is connected to a third wire (224) of the cable, wherein the cable comprises a conductive shield (416) between the third wire and the first and second wires, the conductive shield extending along a longitudinal axis of the cable.

2. The medical device of claim 1 , wherein the conductive shield encloses at least a portion of a longitudinal length of the third wire, and wherein the first wire and the second wire are outside the conductive shield.

3. The medical device of claim 1, wherein the conductive shield encloses at least a portion of a longitudinal length of the first wire and at least a portion of a longitudinal length of the second wire, and wherein the third wire is outside of the conductive shield.

4. The medical device of any of claims 1-3, wherein the conductive shield is cylindical.Attorney Docket No. A0012215W0015. The medical device of any of claims 1-4, wherein the conductive shield encloses at least a portion of a drain wire that is configured to return current to the generator from the conductive shield.

6. The medical device of claim 5, wherein the conductive shield is in contact with the drain wire.

7. The medical device of any of claims 1-6, wherein the tool includes one or more switches configured to select either activation of the first jaw electrode or activation of the cutting electrode.

8. The medical device of claim 7, wherein the conductive shield further encloses one or more switch wires that are connected to the one or more switches.

9. A medical device, comprising: a first electrode (112); a second electrode (114); a third electrode (116); a cable (104) comprising: a first wire (220) connected to the first electrode; a second wire (222) connected to the second electrode; a third wire (224) connected to the third electrode; andAttorney Docket No. A0012215W001 a conductive shield (416) between the third wire and the first and second wires, the conductive shield extending along a longitudinal axis of the cable.

10. The medical device of claim 9, wherein the conductive shield encloses at least a portion of a longitudinal length of the third wire, and wherein the first wire and the second wire are outside the conductive shield.

11. The medical device of claim 9, wherein the conductive shield encloses at least a portion of a longitudinal length of the first wire and at least a portion of a longitudinal length of the second wire, and wherein the third wire is outside of the conductive shield.

12. The medical device of any of claims 9-11, wherein the cable comprises a drain wire that is in contact with the conductive shield.

13. The medical device of any of claims 9-11, wherein the cable comprises a fourth wire connected to a switch of the medical device, wherein the switch is configured to select the first electrode or the third electrode for activation.

14. The medical device of claim 13, wherein the conductive shield encloses at least a portion of a longitudinal length of the fourth wire.

15. The medical device of claim 13, wherein the fourth wire is outside the conductive shield.

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