Electrosurgical instruments, electrosurgical electrodes, and methods for making electrodes for electrosurgical instruments

Abstract

In one example, an electrosurgical electrode of an electrosurgical instrument may include a proximal end configured to receive electrosurgical energy from the electrosurgical instrument and a distal end opposite the proximal end. The electrosurgical electrode may further include a cutting electrode portion extending from the proximal end to the distal end. The cutting electrode portion is configured to cut tissue using the electrosurgical energy received from the electrosurgical instrument. The electrosurgical electrode may further include a coagulation electrode portion extending from the proximal end to the distal end. The coagulation electrode portion is configured to coagulate tissue using the electrosurgical energy received from the electrosurgical instrument. The electrosurgical electrode may further include an insulator between the cutting electrode portion and the coagulation electrode portion.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 949,926, filed December 18, 2019, the contents of which are hereby incorporated by reference in their entirety.

[0002] The present disclosure relates generally to methods and apparatus for delivering electrical energy, and more particularly to electrosurgical instruments and methods that can activate select portions of electrosurgical electrodes in accordance with a selected mode of surgery. [Background technology]

[0003] Electrosurgery is the application of radio frequency (RF) electrical current (also called electrosurgical energy) to biological tissue to cut, coagulate, or modify the biological tissue during an electrosurgical procedure. Specifically, an electrosurgical generator generates and supplies the electrical current to an active electrode, which applies the electrical current (and therefore the power) to the tissue. The electrical current passes through the tissue and returns to the generator via a return electrode (also called a "dispersive electrode"). As the electrical current passes through the tissue, the impedance of the tissue converts a portion of the electrical current into thermal energy (e.g., through the principles of resistive heating), which increases the temperature of the tissue and induces changes to the tissue (e.g., cutting, coagulating, ablating, and / or sealing the tissue).

[0004] The novel features believed characteristic of the illustrative embodiments are set forth in the appended claims, however, the illustrative embodiments will be best understood by reference to the following detailed description of the exemplary embodiments of the present disclosure, together with the method of use, further objects and explanations thereof, when read in conjunction with the accompanying drawings, wherein: [Brief description of the drawings]

[0005] [Figure 1] 1 is a simplified block diagram of an electrosurgical system, according to one example. [Diagram 2] FIG. 1 is a perspective view of an electrosurgical instrument, according to one example. [Figure 3A] FIG. 1 is a perspective view of an electrosurgical electrode, according to one example. [Figure 3B] 3B is an exploded view of the electrosurgical electrode shown in FIG. 3A, according to one example. [Figure 3C] 3B is a cross-sectional view of the electrosurgical electrode shown in FIG. 3A, according to one example. [Figure 4] 2 is a schematic circuit diagram of the electrosurgical system of FIG. 1, according to one example. [Diagram 5] 2 is a schematic circuit diagram of the electrosurgical system of FIG. 1, according to another example. [Figure 6] 2 is a schematic circuit diagram of the electrosurgical system of FIG. 1, according to another example. [Figure 7] 1 is a flowchart of a process for manufacturing an electrosurgical electrode of an electrosurgical instrument, according to one example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] The disclosed embodiments will now be described more fully with reference to the accompanying drawings, in which some, but not all, of the disclosed embodiments are shown. Indeed, several different embodiments may be described, and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are described so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0007] The terms "about" or "substantially" refer to amounts or measurements set forth herein, and mean that the recited property, parameter, or value will not be exactly achieved, but deviations or variations, including, for example, tolerances, measurement errors, measurement accuracy limits, and other factors known to those of skill in the art, may occur in an amount that does not interfere with the effect that the property was intended to provide.

[0008] As described above, during an electrosurgical procedure, an electrosurgical generator generates and supplies electrosurgical energy to electrosurgical electrodes, which apply the electrosurgical energy (and thus power) to the patient's tissue. Generally, the electrosurgical generator varies the output and / or waveform of the electrosurgical energy applied to the electrosurgical instrument to operate the electrosurgical instrument in various surgical modes.

[0009] In conventional electrosurgical systems, electrosurgical energy is conducted through the entirety of the electrosurgical electrode in all surgical modes. The present disclosure provides electrosurgical systems, instruments, electrodes, and methods that may further enhance the characteristics of the electrosurgical energy applied to the patient's tissue by selectively applying electrosurgical energy to different portions of the electrosurgical electrode based on the surgical mode in which the electrosurgical instrument is operated. Among other examples, different portions of the electrosurgical electrode may have a number of different sizes and / or a number of different shapes that may help enhance one or more characteristics of the electrosurgical energy applied to the target tissue. In this manner, the electrosurgical electrode may enhance and / or improve the surgical performance of the electrosurgical instrument relative to conventional electrosurgical instruments that conduct electrosurgical energy through the entirety of the electrosurgical electrode in all surgical modes.

[0010] In one example, an electrosurgical electrode of an electrosurgical instrument may include a proximal end configured to receive electrosurgical energy from the electrosurgical instrument and a distal end opposite the proximal end. The electrosurgical electrode may further include a cutting electrode portion extending from the proximal end to the distal end. The cutting electrode portion is configured to cut tissue using the electrosurgical energy received from the electrosurgical instrument. Additionally, the electrosurgical electrode may further include a coagulation electrode portion extending from the proximal end to the distal end. The coagulation electrode portion is configured to coagulate tissue using the electrosurgical energy received from the electrosurgical instrument. The electrosurgical electrode may further include an insulator between the cutting electrode portion and the coagulation electrode portion.

[0011] In another example, an electrosurgical system includes an electrosurgical electrode and an electrosurgical instrument. The electrosurgical electrode includes a proximal end configured to receive electrosurgical energy from the electrosurgical instrument and a distal end opposite the proximal end. The electrosurgical electrode further includes a cutting electrode portion extending from the proximal end to the distal end, a coagulation electrode portion extending from the proximal end to the distal end, and insulation between the cutting electrode portion and the coagulation electrode portion. The cutting electrode portion is configured to cut tissue using the electrosurgical energy received from the electrosurgical instrument, and the coagulation electrode portion is configured to coagulate tissue using the electrosurgical energy received from the electrosurgical instrument.

[0012] The electrosurgical instrument includes a housing having a distal end and a proximal end, at least one electrical conductor configured to couple to an electrosurgical generator at the proximal end, a receptacle configured to couple to a proximal end of an electrosurgical electrode at the distal end, and at least one user input device configured to select between a cut operation mode and a coagulation operation mode. In the cut operation mode, the electrosurgical instrument delivers electrosurgical energy from the at least one electrical conductor to a cut electrode portion of the electrosurgical electrode and not to a coagulation electrode portion of the electrosurgical electrode. In the coagulation operation mode, the electrosurgical instrument delivers electrosurgical energy from the at least one electrical conductor to at least a coagulation electrode portion of the electrosurgical electrode.

[0013] In another example, a method of making an electrosurgical electrode for an electrosurgical instrument includes forming a cutting electrode, forming a coagulation electrode, disposing insulation between the cutting electrode and the coagulation electrode, and coupling the cutting electrode to the coagulation electrode with the insulation between the cutting electrode and the coagulation electrode. The cutting electrode is configured to cut tissue using electrosurgical energy received from the electrosurgical instrument. The coagulation electrode is configured to coagulate tissue using electrosurgical energy received from the electrosurgical instrument.

[0014] Referring now to Figure 1, an electrosurgical system 100, according to one example, is shown. As shown in Figure 1, electrosurgical system 100 includes an electrosurgical generator 110 and an electrosurgical instrument 112. Generally, electrosurgical generator 110 can generate electrosurgical energy suitable for performing electrosurgery on a patient. For example, electrosurgical generator 110 can include a power converter circuit 114 that can convert grid power into electrosurgical energy, such as, for example, radio frequency (RF) output power. By way of example, power converter circuit 114 can include one or more electrical components (e.g., one or more transformers) that can control the voltage, current, and / or frequency of the electrosurgical energy.

[0015] Among other examples, electrosurgical generator 110 may include a user interface 116 that receives one or more inputs from a user and / or provides one or more outputs to a user. By way of example, user interface 116 may include one or more buttons, one or more switches, one or more dials, one or more keypads, one or more touch screens, and / or one or more display screens.

[0016] In one example, user interface 116 may be operable to select a surgical mode from among a plurality of surgical modes of electrosurgical generator 110. By way of example, the surgical modes may include a cutting mode, a coagulation mode, an ablation mode, and / or a sealing mode. A combination of these waveforms may also be formed to generate a mixed mode. In an embodiment, a surgical mode may correspond to a respective waveform of the electrosurgical energy. Thus, in this embodiment, electrosurgical generator 110 may generate electrosurgical energy having a waveform selected from a plurality of waveforms based at least in part on the surgical mode selected using user interface 116.

[0017] Electrosurgical generator 110 may further include one or more sensors 118 that may sense one or more conditions related to the electrosurgical energy and / or the target tissue. By way of example, sensors 118 may include one or more current sensors, one or more voltage sensors, one or more temperature sensors, and / or one or more bioimpedance sensors. Among other examples, electrosurgical generator 110 may additionally or alternatively generate an amount of electrosurgical energy (e.g., power) and / or electrosurgical energy having a waveform selected from among a plurality of waveforms based on one or more parameters related to the condition sensed by sensor 118.

[0018] In one example, the electrosurgical energy may have a frequency greater than about 100 kilohertz (kHz) to reduce (avoid) stimulating muscles and / or nerves near the target tissue, hi another example, the electrosurgical energy may have a frequency of about 300 kHz to about 500 kHz.

[0019] 1 , electrosurgical generator 110 further includes a connector 120 that may assist in coupling electrosurgical generator 110 to electrosurgical instrument 112. For example, electrosurgical instrument 112 may include a power cord 122 having a plug that may be coupled to a socket of connector 120 of electrosurgical generator 110. In this configuration, electrosurgical generator 110 may supply electrosurgical energy to electrosurgical instrument 112 via the coupling between connector 120 of electrosurgical generator 110 and power cord 122 of electrosurgical instrument 112.

[0020] 1, electrosurgical instrument 112 may include a housing 124 defining an internal chamber, a shaft 126 extending distally from housing 124, and an electrosurgical electrode 128 coupled to shaft 126. In general, housing 124 may be configured to assist a user in gripping and manipulating electrosurgical instrument 112 while performing electrosurgery. For example, housing 124 may have a shape and / or size that may assist a user in performing electrosurgery by manipulating electrosurgical instrument 112 using one hand. In an embodiment, housing 124 may have a shape and / or size that assists a user in holding electrosurgical instrument 112 in the manner of gripping a writing instrument (e.g., electrosurgical instrument 112 may be an electrosurgical pencil).

[0021] Additionally, for example, housing 124 may be constructed from one or more materials that are electrical insulators (e.g., a plastic material), which may help insulate the user from the electrosurgical energy that flows through electrosurgical instrument 112 during the performance of electrosurgery.

[0022] In some embodiments, shaft 126 may be fixedly coupled to housing 124. In some embodiments, shaft 126 may be telescopically movable relative to housing 124 (in a telescopic manner). For example, shaft 126 may be telescopically movable within an internal bore defined by housing 124 to extend shaft 126 distally and retract shaft 126 proximally relative to housing 124 (e.g., movable along the longitudinal axis of electrosurgical instrument 112). As discussed above, electrosurgical electrodes 128 are coupled to shaft 126 such that electrosurgical electrodes 128 move with shaft 126 relative to housing 124. This allows for adjustment of the length of electrosurgical instrument 112, which may assist in performing electrosurgery at different depths within tissue (e.g., due to various anatomical shapes and / or patient sizes) and / or at different angles.

[0023] In some examples, shaft 126 may additionally or alternatively be rotatable about an axis of rotation parallel to the longitudinal axis of electrosurgical instrument 112. In another example, electrode 128 may additionally or alternatively be rotatable relative to shaft 126. Shaft 126 and / or electrosurgical electrode 128 rotating relative to housing 124 may assist in adjusting the angle of electrosurgical electrode 128 relative to one or more user input devices 130 of electrosurgical instrument 112. In this configuration, a user may comfortably grip housing 124 in a position where their fingers may comfortably operate user input device 130 while electrosurgical electrode 128 is set at a rotational position selected from a plurality of rotational positions relative to housing 124 based, for example, on the size and / or shape of the surgical site at which the user is operating.

[0024] User input device 130 may select between surgical modes of electrosurgical instrument 112 and / or electrosurgical generator 110. For example, in one embodiment, user input device 130 may be configured to select between a cut surgical mode and a coagulation surgical mode. In response to actuation of user input device 130 of electrosurgical instrument 112, electrosurgical instrument 112 may (i) receive electrosurgical energy having a power level and / or waveform corresponding to the surgical mode selected via user input device 130, and (ii) supply electrosurgical energy to electrosurgical electrode 128.

[0025] 1 , electrosurgical instrument 112 may include a number of electrical components that assist in delivering electrosurgical energy that electrosurgical instrument 112 receives from electrosurgical generator 110 to electrosurgical electrodes 128. For example, electrosurgical instrument 112 may include a printed wiring board 132 (e.g., a flexible printed wiring board), housing conductors 134, one or more conductive leads 136, and / or receptacles 137 that may provide circuitry for conducting electrosurgical energy from power cord 122 to electrosurgical electrodes 128. Any one or more of the electrical components may be disposed in an interior space defined by housing 124.

[0026] Among other examples, user input device 130 may include one or more buttons on an exterior surface of housing 124. Each button of user input device 130 may be operable to operate a respective one of a plurality of switches 138 on printed wiring board 132. In general, switches 138 and / or printed wiring board 132 are operable to control the delivery of electrosurgical energy from electrosurgical generator 110 to electrosurgical electrodes 128. For example, in one embodiment, when each button is actuated (e.g., pressed), the respective switch 138 associated with the button may be operated to cause printed wiring board 132 to send a signal to electrosurgical generator 110 to responsively supply electrosurgical energy to electrosurgical generator 110 having a power level and / or waveform corresponding to the surgical mode associated with the button. In another embodiment, actuation of a button, thereby operating a respective switch 138 associated with the button, may close switch 138, completing a circuit to electrosurgical generator 110, responsively supplying electrosurgical energy having a power level and / or waveform corresponding to the surgical mode associated with the button to electrosurgical generator 110. In some implementations of this embodiment, printed wiring board 132 may be omitted.

[0027] In both of the illustrated embodiments, electrosurgical energy supplied by electrosurgical generator 110 may be supplied (i) from power cord 122, printed wiring board 132, and / or switch 138 to (ii) electrosurgical electrode 128 by way of housing conductors 134 and conductive leads 136. As shown in FIG. 1 , printed wiring board 132 may be coupled to power cord 122, housing conductors 134 may be coupled to printed wiring board 132 and conductive leads 136, which may be coupled to electrosurgical electrode 128 (via receptacle 137). In this configuration, housing conductors 134 may conduct electrosurgical energy (supplied to housing conductors 134 via printed wiring board 132) to conductive leads 136, and conductive leads 136 and receptacle 137 may conduct the electrosurgical energy to electrosurgical electrode 128.

[0028] In general, the housing conductors 134 may include one or more conductive elements that provide a conductive bus for supplying electrosurgical energy to the electrosurgical electrode 128. In one example, the housing conductors 134 may be formed in a helical shape. In this configuration, the housing conductors 134 may be compressible and expandable such that the housing conductors 134 may accommodate the shaft 126, which moves telescopically in and / or out of the housing 124, respectively contracting and / or expanding the electrosurgical electrode 128 relative to the housing 124. In another example, the conductive leads 136 may include one or more wires. In another example, the conductive leads 136 may include one or more conductive traces formed, for example, by screen printing, sputtering, electroplating, conductive paint, and / or laser ablation.

[0029] Among other examples, conductive lead 136 may extend from housing conductor 134 to electrosurgical electrode 128. In one example, conductive lead 136 may include one or more wires. In another example, conductive lead 136 may include one or more conductive traces formed, for example, by screen printing, sputtering, electroplating, conductive paint, and / or laser ablation. Conductive lead 136 may be disposed within an internal conduit of shaft 126, and the exterior surface of shaft 126 may be constructed from an electrical insulator. This may help reduce (or prevent) loss of electrosurgical energy to electrosurgical electrode 128.

[0030] Receptacle 137 may couple electrosurgical electrode 128 to electrosurgical instrument 112. By way of example, receptacle 137 and electrosurgical electrode 128 may be configured to couple to one another via a friction fit. Thus, receptacle 137 and electrosurgical electrode 128 may have respective sizes and / or respective shapes that provide a friction fit coupling between receptacle 137 and electrosurgical electrode 128 when electrosurgical electrode 128 is inserted into receptacle 137. This may allow the electrosurgical electrode to be removably coupled to electrosurgical instrument 112, which may aid in interchangeability of multiple electrosurgical electrodes 128 with electrosurgical instrument 112. Receptacle 137 and electrosurgical electrode 128 may be mechanically secured to ensure that a correct electrical connection is made. In other embodiments, the electrosurgical electrode 128 may be coupled to the receptacle 137 by another type of removable connection (eg, a threaded connection) or a non-removable connection (eg, by welding and / or soldering).

[0031] Among other examples, receptacle 137 may further include electrical conductors that may electrically couple electrosurgical electrode 128 to electrosurgical energy supplied to electrosurgical instrument 112 by electrosurgical generator 110. For example, receptacle 137 may be electrically coupled to conductive lead 136 (e.g., by an electrically conductive material).

[0032] As shown in FIG. 1, the electrosurgical instrument 112 may further include a light source 140 configured to emit light. In the example of FIG. 1, the light source 140 may be optically coupled to a light guide 142 configured to receive the light emitted by the light source 140 and transmit the light distally towards the surgical site to illuminate the surgical site during the performance of electrosurgery using the electrosurgical electrode 128. Among other examples, the light guide 142 may transmit the light distally via total internal reflection. For example, the light guide may include a coating and / or voids on an outer surface of the light guide 142. In some implementations, the light guide 142 may be formed as a single, unitary structure. In another example, the electrosurgical instrument 112 may omit the light guide 142 and not transmit light through the light guide 142, but instead emit light directly from the light source 140 into the surgical field.

[0033] 1, light source 140 is coupled to shaft 126. As such, light source 140 may also move telescopically with shaft 126 relative to housing 124. However, in other examples, light source 140 may be coupled to housing 124. By way of example, light source 140 may include one or more light emitting diodes (LEDs), organic light emitting diodes (OLEDs), optical fibers, non-fiber optical waveguides, and / or lenses.

[0034] The light guide 142 may be at the distal end of the shaft 126. In some embodiments, the electrosurgical electrode 128 may extend from a central portion of the light guide 142. As such, the light guide 142 may completely surround the electrosurgical electrode 128 and emit light distally around all sides of the electrosurgical electrode 128. This helps reduce shadowing and provide better illumination uniformity at all rotational positioning of the shaft 126 relative to the housing 124 and / or the electrosurgical instrument 112 relative to the target tissue.

[0035] In embodiments including a light source 140, the user input device 130, the printed wiring board 132, the switch 138, the housing conductors 134, and / or the conductive leads 136 may further provide power to the light source 140 from a direct current (DC) power source 144. In one example, the DC power source 144 may include a battery disposed in the housing 124 and / or a plug of the power cord 122. Although the electrosurgical instrument 112 includes the DC power source 144 in FIG. 1 , the DC power source 144 may be separate and distinct from the electrosurgical instrument 112 in other examples. For example, in another example, the electrosurgical generator 110 may include the DC power source 144.

[0036] Additionally, in embodiments including a light source 140, user input device 130 may be operable to cause light source 140 to emit light. In one example, user input device 130 may include a button that solely controls light source 140, separate from the buttons that control the electrosurgical mode of electrosurgical instrument 112. In another example, user input device 130 and printed wiring board 132 may be configured such that operation of the button that controls the electrosurgical mode simultaneously controls operation of light source 140 (e.g., light source 140 may be automatically operated to emit light when operated to apply electrosurgical energy at electrosurgical electrode 128).

[0037] 1 , in response to manipulation of user input device 130 to operate light source 140, DC power source 144 may provide power (e.g., a DC voltage) to light source 140 via printed wiring board 132, housing conductors 134, and / or conductive leads 136. In this embodiment, one or more of the conductive elements of housing conductors 134 may be configured to provide power from DC power source 144 to light source 140 and / or return power from light source 140 to DC power source 144. Thus, housing conductors 134 may additionally or alternatively assist in providing electrical communication between DC power source 144 and light source 140 as shaft 126 and light source 140 move telescopically relative to housing 124.

[0038] As mentioned above, the electrosurgical instrument 112 may further include features that provide for evacuating surgical smoke from the target tissue to the exterior of the surgical site. Surgical smoke is a by-product of various surgical procedures. For example, during a surgical procedure, surgical smoke may be generated as a by-product of electrosurgical units (ESUs), lasers, electrocautery devices, ultrasonic devices, and / or other powered surgical instruments (e.g., bone saws and / or drills). In some instances, surgical smoke may include toxic gases and / or biological products resulting from the destruction of tissue. Additionally, surgical smoke may include an unpleasant odor. For these and other reasons, many guidelines indicate that surgical personnel's exposure to surgical smoke should be reduced or minimized.

[0039] To reduce (or minimize) exposure to surgical smoke, a smoke exhaust system may be used during a surgical procedure. Generally, a smoke exhaust system may include a pump 146 that may generate sufficient suction and / or vacuum pressure to draw surgical smoke away from the surgical site. In some embodiments, the smoke exhaust system may be coupled to an exhaust system (e.g., an internal wall exhaust system) that exhausts the surgical smoke outside the operating room. In other embodiments, the smoke exhaust system may filter the air containing the surgical smoke and return the air to the operating room. Among other examples, the pump 146 and the electrosurgical generator 110 may be provided as separate devices or may be integrated into a single device (e.g., within a common housing).

[0040] As shown in FIG. 1 , the shaft 126 may include a smoke exhaust channel 148 at the distal end of the shaft 126. In one example, the smoke exhaust channel 148 may extend completely around the optical waveguide 142 at the distal end of the shaft 126. The smoke exhaust flow passage 148 may further include a smoke inlet that extends completely around the optical waveguide 142 at the distal end of the shaft 126. In this configuration, the smoke inlet of the smoke exhaust flow passage may assist in receiving surgical smoke into the smoke exhaust flow passage 148 at all rotational positioning of the shaft 126 relative to the housing 124 and / or the electrosurgical instrument 112 relative to the target tissue. However, in another example, the smoke exhaust flow passage 148 may include one or more smoke inlets that do not extend completely around the optical waveguide 142 and / or the electrosurgical electrode 128.

[0041] In some embodiments, the smoke exhaust channel 148 and the optical waveguide 142 may be coaxial. For example, the smoke exhaust channel 148 and the optical waveguide 142 may each have a longitudinal axis aligned with the central axis of the shaft 126. In other embodiments, the smoke exhaust channel 148 and the optical waveguide 142 have their respective longitudinal axes offset with respect to each other, such that the smoke exhaust channel 148 and the optical waveguide 142 are not coaxial.

[0042] In one example, the smoke exhaust flow channel 148 may include an outer tube separated from the light guide 142 by an air gap. For example, the shaft 126 may include a plurality of support rods extending between the light guide 142 and the outer tube of the smoke exhaust channel 148 to provide an air gap between the outer tube and the light guide 142. In an embodiment, the light guide 142 may include a support rod such that the light guide 142 and the support rod form a single, integral structure. In another embodiment, the support rod may be formed as a single, integral structure with the outer tube of the smoke exhaust channel 148. In another embodiment, the support rod may be separated from the outer tube of the smoke exhaust channel 148 and the light guide 142.

[0043] In one example, the smoke exhaust passage 148 of the shaft 126 defines a first portion of the smoke flow passage, and the interior of the housing 124 defines a second portion of the smoke flow passage. In this configuration, surgical smoke may be received from the surgical site into the smoke exhaust passage 148 of the shaft 126 and flow proximally along the smoke exhaust passage 148 to the interior of the housing 124. In the interior of the housing 124, the smoke may further flow to a smoke conduit 150 coupled to a proximal end of the housing 124 and configured to transport the smoke from the housing 124 to the pump 146.

[0044] 2, a perspective view of an embodiment of an electrosurgical instrument 112 is shown, according to one example. As shown in FIG. 2, electrosurgical instrument 112 can include a housing 124, a shaft 126 telescopically movable within an interior of housing 124, and an electrosurgical electrode 128 coupled to shaft 126. However, as noted above, in other examples, shaft 126 can be fixedly coupled to housing 124 so as not to be movable.

[0045] Further, in FIG. 2 , the light guide 142 is at the distal end 252 of the shaft 126. In this arrangement, the light guide 142 may telescopically move with the shaft 126 relative to the housing 124. In FIG. 2 , the light guide 142 extends around the electrosurgical electrode 128. This may assist in emitting light in a relatively uniform manner by reducing (or avoiding) shading due to the orientation of the light guide 142 and the electrosurgical electrode 128 relative to the surgical site. However, in other examples, the light guide 142 does not extend entirely around the electrosurgical electrode 128 at the distal end 252 of the shaft 126 and / or the light guide 142 may be at a different location on the shaft 126 and / or housing 124.

[0046] In some embodiments, the electrosurgical instrument 112 may include a collar 254 at the proximal end of the housing 124. The collar 254 may be rotatable relative to the housing 124 and may increase and / or decrease friction between an outer surface of the shaft 126 and an inner surface of the collar 254. In this manner, the collar 254 may allow and / or prevent axial telescopic and / or rotational movement of the shaft 126 relative to the housing 124.

[0047] 2, electrosurgical instrument 112 includes a power cord 122. At a proximal end 256 of power cord 122, power cord 122 includes a plug 258 configured to couple to connector 120 of electrosurgical generator 110. A distal end of power cord 122 is coupled to printed wiring board 132 within the internal cavity of housing 124. In this configuration, power cord 122 extends proximally from housing 124 to plug 258.

[0048] 2, user input device 130 includes a first button 230A, a second button 230B, and a third button 230C on the exterior surface of housing 124. In one embodiment, first button 230A can be operated to operate electrosurgical instrument 112 in a cutting surgical mode, second button 230B can be operated to operate electrosurgical instrument 112 in a coagulation surgical mode, and third button 230C can be operated to operate light source 140 (i.e., cause light source 140 to emit light or terminate light emission). As mentioned above, user input device 130 can be configured differently in other examples. For example, electrosurgical instrument 112 can be operable with a lower amount of heat in a surgical mode, a higher amount of heat in a surgical mode, and / or in various surgical modes (e.g., the exemplary surgical modes described above) in other examples. Further, for example, at least one user input device 130 may additionally or alternatively comprise a user interface 116 of the electrosurgical generator 110 and / or another external device (e.g., a foot switch) for operating the electrosurgical instrument 112 in one or more surgical modes.

[0049] Among other examples, electrosurgical electrode 128 may provide for selective application of electrosurgical energy to different portions of electrosurgical electrode 128 based on the surgical mode in which electrosurgical instrument 112 is operated. Different portions of electrosurgical electrode 128 may have a number of different sizes and / or a number of different shapes that may help enhance one or more characteristics of the electrosurgical energy applied to the target tissue. In this manner, electrosurgical electrode 128 may enhance and / or improve the surgical performance of electrosurgical instrument 112 relative to conventional electrosurgical instruments that conduct electrosurgical energy through the entirety of electrosurgical electrode 128 for all surgical modes.

[0050] Figures 3A-3C illustrate an example electrosurgical electrode 128. Specifically, Figure 3A illustrates a partial perspective view of electrosurgical electrode 128, Figure 3B illustrates an exploded view of electrosurgical electrode 128, and Figure 3C illustrates a cross-sectional view of electrosurgical electrode 128 through line 3C of Figure 3A.

[0051] 3A-3C, electrosurgical electrode 128 includes a proximal end 360 configured to receive electrosurgical energy from electrosurgical instrument 112, and a distal end 362 opposite proximal end 360. Proximal end 360 is capable of receiving electrosurgical energy from electrosurgical instrument 112, as described in detail below. Distal end 362 may define a working end configured to cut and coagulate tissue using the electrosurgical energy.

[0052] 3A-3C, electrosurgical electrode 128 further includes a cutting electrode portion 364 extending from a proximal end 360 to a distal end 362, a coagulation electrode portion 366 extending from the proximal end 360 to the distal end 362, and insulator 368 between cutting electrode portion 364 and coagulation electrode portion 366. Cutting electrode portion 364 and coagulation electrode portion 366 may include an electrically conductive material (e.g., stainless steel) for conducting electrosurgical energy received from electrosurgical instrument 112 at proximal end 360 to distal end 362. As described in further detail below, cutting electrode portion 364 and coagulation electrode portion 366 may define separate portions of electrosurgical electrode 128 that may be selectively energized to apply electrosurgical energy to target tissue according to a selected surgical mode.

[0053] The insulator 368 may electrically isolate the cutting electrode 364 from the coagulation electrode 366 along the entire length 370 of the electrosurgical electrode 128 in a direction parallel to the longitudinal axis of the electrosurgical electrode 128. The insulator 368 may include electrical insulation that may prevent conduction of electrosurgical energy between the cutting electrode 364 and the coagulation electrode 366. In this manner, the insulator 368 may assist in the conduction of electrosurgical energy through one of the cutting electrode 364 or the coagulation electrode 366 with negligible or no electrosurgical energy being conducted through the other of the cutting electrode 364 or the coagulation electrode 366.

[0054] For example, the insulator 368 may include a material selected from the group consisting of plastic, ceramic, and enamel. Further, for example, the insulator 368 may have a thickness that is equal to or greater than the thickness of the cutting electrode 364 and / or the coagulation electrode 366. In one example, the insulator 368 may have a width of about 0.1 millimeters (mm) to about 0.5 mm. This may help electrically insulate the cutting electrode 364 and the coagulation electrode 366 from one another. While it may be beneficial to separate the cutting electrode 364 and the coagulation electrode 366 by the insulator 364, in another example, the cutting electrode 364 and the coagulation electrode 366 may be separated by an air gap.

[0055] 3A-3C, cutting electrode 364 is configured to cut tissue using electrosurgical energy received from electrosurgical instrument 112, and coagulation electrode 366 is configured to coagulate tissue using electrosurgical energy received from electrosurgical instrument 112. For example, the surface area of ​​cutting electrode 364 may be smaller than the surface area of ​​coagulation electrode 366. This may assist in achieving a relatively large electrosurgical energy density when electrosurgical energy is applied to cutting electrode 364 and a relatively small electrosurgical energy density when electrosurgical energy is applied to coagulation electrode 366. The relatively large electrosurgical energy density assists in improved performance during a cutting procedure, and the relatively small electrosurgical energy density assists in improved performance during a coagulation procedure, and the relative sizes of cutting electrode 364 and coagulation electrode 366 may assist in improved performance of electrosurgical instrument 112.

[0056] In one example, the surface area of ​​cutting electrode 364 is between about 5 percent and about 50 percent of the surface area of ​​coagulating electrode 366. In another example, the surface area of ​​cutting electrode 364 is between about 5 percent and about 35 percent of the surface area of ​​coagulating electrode 366. In another example, the surface area of ​​cutting electrode 364 is between about 10 percent and about 25 percent of the surface area of ​​coagulating electrode 366.

[0057] The cutting electrode 364 and the coagulation electrode 366 may additionally or alternatively have a variety of shapes to improve a cutting procedure using the cutting electrode 364 and / or a coagulation procedure using the coagulation electrode 366. For example, as shown in FIG. 3C , the electrosurgical electrode 128 may include a first side 372 extending between the proximal end 360 and the distal end 362, a second side 374 extending between the proximal end 360 and the distal end 362, a first edge 376 located at a first lateral interface between the first side 372 and the second side 374, and a second edge 378 located at a second lateral interface between the first side 372 and the second side 374. First and second sides 372, 374 are on either side of an intermediate plane 380 that extends through a first edge 376 and a second edge 378. The cutting electrode portion 364 includes a first edge 376 and the coagulation electrode portion 366 includes a second edge 378.

[0058] 3C , first edge 376 is thinner and sharper than second edge 378. This may additionally or alternatively assist in achieving a relatively greater electrosurgical energy density when electrosurgical energy is applied to cutting electrode 364 and a relatively lesser electrosurgical energy density when electrosurgical energy is applied to coagulation electrode 366. In this manner, first edge 376 of cutting electrode 364 may assist in achieving relatively better performance for cutting procedures than second edge 378 of coagulation electrode 366, which may assist in achieving relatively better performance for coagulation procedures than first edge 376 of cutting electrode 364.

[0059] As discussed above, the insulator 368 isolates and prevents electrical coupling between the cutting electrode 364 and the coagulation electrode 366. In one example, a longitudinal axis extends from the proximal end 360 toward the distal end 362, and along the longitudinal axis the cutting electrode 364 and the coagulation electrode 366 are separated by about 0.1 mm to about 0.5 mm. This separation distance may help to prevent electrical coupling between the cutting electrode 364 and the coagulation electrode 366.

[0060] Among other examples, the cutting electrode 364 and / or the coagulation electrode 366 may be coated with a non-adherent material (a material having a relatively low coefficient of friction) including at least one material selected from silicone, siloxane, and Teflon (PTFE). This may help reduce tissue adhesion to the electrosurgical electrode 128. When tissue adheres to the electrosurgical electrode, the tissue may change the effective size and / or shape of the electrode. As such, tissue adhesion may impair the ability to make relatively narrow, precise incisions, thereby adversely affecting the quality and / or speed of the electrosurgical procedure. However, cutting electrode 364 and coagulation electrode 366 with a non-adherent material having a relatively low coefficient of friction may help reduce tissue adhesion to the electrosurgical electrode 128 as the electrosurgical electrode 128 moves through the target tissue during electrosurgery, improving the quality and / or speed of the electrosurgical procedure.

[0061] In some examples, the cutting electrode 364 and / or the coagulation electrode 366 may additionally or alternatively be coated with an insulating material, such as, for example, a polymeric material and / or a fluorocarbon material (e.g., polytetrafluoroethylene (PTFE)). In one example, the insulating material layer may be a coating (e.g., an insulating enamel).

[0062] As described above, the proximal end 360 of the electrosurgical electrode 128 can receive electrosurgical energy from the electrosurgical instrument 112. For example, as described above, the electrosurgical electrode 128 can be coupled to the receptacle 137 by a removable connection (e.g., a friction fit or a threaded connection) or a non-removable connection (e.g., by welding and / or soldering). In one embodiment, the receptacle 137 is configured to removably couple to the proximal end 360 of the electrosurgical electrode 128 by a friction fit connection.

[0063] Among other examples, electrosurgical instrument 112 and electrosurgical electrodes 128 selectively apply electrosurgical energy to (i) only the cutting electrode 364, (ii) only the coagulation electrode 366, and / or (iii) both the cutting electrode 364 and the coagulation electrode 366. This may be accomplished by providing electrosurgical instrument 112 with multiple electronic circuits for coupling the cutting electrode 364 and the coagulation electrode 366 to electrosurgical generator 110.

[0064] Figure 4 shows a schematic circuit diagram of electrosurgical system 100, according to one example. In the example shown in Figure 4, electrosurgical energy is conducted through cutting electrode 364 and not through coagulation electrode 366 when electrosurgical instrument 112 is operated in a cutting procedure, and electrosurgical energy is conducted through coagulation electrode 366 and not through cutting electrode 364 when electrosurgical instrument 112 is operated in a coagulation procedure.

[0065] For example, in FIGURE 4, the at least one user input device 130 includes a first user input device 430A operable to cause the electrosurgical generator 110 to supply electrosurgical energy to the cutting electrode 364. Additionally, in FIGURE 4, the at least one user input device 130 includes a second user input device 430B operable to cause the electrosurgical generator 110 to supply electrosurgical energy to the coagulation electrode 366. The first user input device 430A may include a first switch operable by a first button 230A (shown in FIGURE 2) to operate the electrosurgical instrument 112 in a cutting surgical mode and a second switch operable by a second button 230B (shown in FIGURE 2) to operate the electrosurgical instrument 112 in a coagulation surgical mode.

[0066] As mentioned above, electrosurgical instrument 112 may include at least one conductor selected from power cord 122, housing conductors 134, and conductive leads 136 for coupling electrosurgical electrode 128 to electrosurgical generator 110. In FIG. 4 , the at least one conductor includes a first conductor 482 configured to couple cutting electrode portion 364 to electrosurgical generator 110 and a second conductor 484 configured to couple coagulation electrode portion 366 to electrosurgical generator 110.

[0067] The at least one conductor further includes a third conductor 486 electrically coupling electrosurgical generator 110 to a first switch of first user input device 430A. The first switch of first user input device 430A is operable between an open state and a closed state. In the open state of the first switch, third conductor 486 is decoupled from first conductor 482 and cutting electrode 364. In the closed state of the first switch, third conductor 486 is coupled to first conductor 482 and cutting electrode 364.

[0068] 4, third conductor 486 further electrically couples electrosurgical generator 110 to a second switch of second user input device 430B. The second switch of second user input device 430B is operable between an open state and a closed state. In the open state of the second switch, third conductor 486 is decoupled from second conductor 484 and cutting electrode 366. In the closed state of the second switch, third conductor 486 is coupled to second conductor 484 and cutting electrode 364.

[0069] In this configuration, when the first switch of the user input device 430A is operated to a closed state and the second switch of the second user input device 430B remains in an open state, the electrosurgical generator 110 supplies electrosurgical energy to the cutting electrode 364 and not to the coagulation electrode 366. On the other hand, when the second switch of the second user input device 430B is operated to a closed state and the first switch of the first user input device 430A remains in an open state, the electrosurgical generator 110 supplies electrosurgical energy to the coagulation electrode 366 and not to the cutting electrode 364.

[0070] Thus, in the cut surgery mode, electrosurgical instrument 112 supplies electrosurgical energy from at least one electrical conductor to the cutting electrode portion 364 of electrosurgical electrode 128, but not to the coagulation electrode portion 366 of electrosurgical electrode 128. On the other hand, in the coagulation surgery mode, electrosurgical instrument 112 supplies electrosurgical energy from at least one electrical conductor to the coagulation electrode portion 366 of electrosurgical electrode 128, but not to the cutting electrode portion 364 of electrosurgical electrode 128.

[0071] 4, electrosurgical system 100 may further include a dispersive electrode 488 and a number of return conductors 490 coupling dispersive electrode 488 to electrosurgical generator 110. Dispersive electrode 488 and return conductors 490 may carry current from the patient back to electrosurgical generator 110.

[0072] 4, electrosurgical energy is conducted through the cutting electrode 364 and not through the coagulation electrode 366 when the electrosurgical instrument 112 is operated in a cut surgery mode, and electrosurgical energy is conducted through the coagulation electrode 366 and not through the cutting electrode 364 when the electrosurgical instrument 112 is operated in a coagulation surgery mode. However, in another example, electrosurgical energy may be conducted through both the coagulation electrode 366 and the cutting electrode 364 when the electrosurgical instrument 112 is operated in a coagulation surgery mode.

[0073] Figure 5 shows a schematic circuit diagram of electrosurgical system 100 according to one such example. The schematic circuit diagram of Figure 5 is substantially similar or identical to the schematic circuit diagram of Figure 4, except that electrosurgical system 100 further includes a fourth electrical conductor 592 that provides for electrically coupling cutting electrode 364 to electrosurgical generator 110 when a second switch of second user input device 430B is operated to a closed state.

[0074] 5, (i) electrosurgical energy is conducted through the cutting electrode 364 and not through the coagulation electrode 366 when the electrosurgical instrument 112 is operated in a cut surgical mode, and (ii) electrosurgical energy is conducted through the coagulation electrode 366 and through the cutting electrode 364 when the electrosurgical instrument 112 is operated in a coagulation surgical mode. This increases the surface area of ​​the electrosurgical electrode 128 that conducts electrosurgical energy and therefore may help to reduce the density of electrosurgical energy when the electrosurgical instrument 112 is used in a coagulation surgical mode.

[0075] As mentioned above, disposing insulator 368 between cutting electrode 364 and coagulation electrode 366 can help prevent electrosurgical energy from being conducted between cutting electrode 364 and coagulation electrode 366. This can allow different portions of electrosurgical electrode 128 to be selectively activated according to various surgical modes.

[0076] In some embodiments, the insulator 368 between the cutting electrode 364 and the coagulation electrode 366 may additionally or alternatively provide the electrosurgical electrode 128 with the function of a sensor that may sense one or more conditions related to the electrosurgery procedure. For example, in one example, the electrosurgical generator 110 may measure the impedance of the target tissue using the electrical properties of the cutting electrode 364 and the coagulation electrode 366. With reference to FIG. 4, in an example where the user input device 430A is operated and the cutting electrode 364 is active, the high impedance of the second conductor 484, while not an open circuit, may be used to allow a relatively small current to pass from the cutting electrode 364 to the coagulation electrode 366. As discussed above, to bypass the insulator 368 between the cutting electrode 364 and the coagulation electrode 366, the current must pass through a portion of the tissue adjacent to the cutting electrode 364 and the coagulation electrode 366. This relatively small current will pass through the tissue and return to the electrosurgical generator 110.

[0077] Electrosurgical generator 110 may then use this current to measure electrical properties such as, for example, impedance, voltage, capacitance, and / or inductance. Electrosurgical generator 110 may determine properties of the tissue to which electrosurgical electrode 128 has applied electrosurgical energy (e.g., tissue impedance, tissue water content, tissue density, tissue fat content, and / or tissue temperature) based on the measured electrical properties. Additionally or alternatively, electrosurgical generator 110 may use the measured electrical properties to set and / or modify the power and / or waveform of the electrosurgical energy delivered to electrosurgical instrument 112. In this manner, electrosurgical electrode 128 may advantageously provide tissue measurement capabilities while electrosurgical device 112 is being used.

[0078] In another example, rather than actuating the cutting electrode 364 and using the high impedance on the second conductor 484 as before, the electrosurgical generator 110 may intermittently form a circuit including the cutting electrode 364 and the coagulation electrode 366 acting as two poles such that the path of least resistance bypasses the insulating layer 368 from the cutting electrode 364 through the adjacent tissue to the coagulation electrode 366. The electrosurgical generator 110 may use this circuit to measure electrical properties and determine tissue properties as described above based on the electrical properties. This measurement may be made on the order of milliseconds so that cutting performance is not significantly affected.

[0079] In another example, the electrical properties between the active portion of the electrosurgical electrode 128 (e.g., the portion being supplied with electrosurgical energy selected from the cutting electrode portion 364 and / or the coagulation electrode portion 366) and the return electrode 488 are measured within the electrosurgical generator 110. For example, the impedance of the tissue adjacent to the electrode 128 may be measured in addition to the impedance between the active portion of the electrosurgical electrode 128 and the return electrode 488. Over multiple measurements, the impedance from the active portion of the electrosurgical electrode 128, through the patient and back to the return electrode 488 is averaged so that a discernible change in impedance is clearly associated with the tissue adjacent the active portion of the electrosurgical electrode 128.

[0080] FIG 6 shows a schematic circuit diagram of an electrosurgical system 100 according to one such example. The schematic circuit diagram of FIG 6 is substantially similar or identical to the schematic circuit diagram of FIG 4, except that electrosurgical system 100 further includes a sensor 694 that provides for measuring an electrical characteristic (e.g., impedance, voltage, phase, capacitance, and / or inductance) across cutting electrode 364 and coagulation electrode 366. In some embodiments, sensor 694 is disposed within electrosurgical generator 110. In some embodiments, sensor 694 is disposed within electrosurgical instrument 112. In either embodiment, sensor 694 can generate a sensor signal indicative of the electrical characteristic measured by sensor 694. Sensor 694 further transmits the sensor signal to electrosurgical generator 110, which can determine a characteristic of the tissue based on the sensor signal and set and / or modify the power and / or waveform of the electrosurgical energy delivered to electrosurgical instrument 112 as described above.

[0081] As described above, electrosurgical generator 110 may perform a variety of operations including, for example, measuring electrical properties, determining tissue properties, setting the waveform and / or output of electrosurgical energy, and / or modifying the waveform and / or output of electrosurgical energy. Among other examples, electrosurgical generator 110 may include one or more controllers configured to perform at least these operations. The controller may be implemented using hardware, software, and / or firmware. For example, the controller may include one or more processors and a non-transitory computer-readable medium (e.g., volatile and / or non-volatile memory) that stores machine language instructions or other executable instructions. The instructions, when executed by the one or more processors, cause electrosurgical generator 110 to perform the various operations illustrated herein. The controller may therefore also receive data and store data in the memory.

[0082] Referring now to Figure 7, a flow chart of a process 700 for manufacturing an electrosurgical electrode of an electrosurgical instrument according to one example is shown. As shown in Figure 7, the process 700 includes forming a cutting electrode at block 710, forming a coagulation electrode at block 712, disposing insulation between the cutting electrode and the coagulation electrode at block 714, and coupling the cutting electrode to the coagulation electrode along with the insulation between the cutting electrode and the coagulation electrode at block 716. The cutting electrode is configured to cut tissue using electrosurgical energy received from the electrosurgical instrument. The coagulation electrode is configured to coagulate tissue using electrosurgical energy received from the electrosurgical instrument.

[0083] Although the description of various advantageous configurations has been presented for purposes of illustration and description, it is not intended to be exhaustive or limiting of the disclosed examples. Many variations and modifications will be apparent to those skilled in the art. Also, various advantageous examples may illustrate advantages different from other advantageous examples. The selected example or examples have been chosen and described to explain the principles, practical applications of the examples, and to allow others skilled in the art to understand that the present disclosure of the various examples with various modifications is suitable for the particular use intended.

Claims

1. 1. An electrosurgical system comprising an electrosurgical electrode and an electrosurgical instrument, The electrosurgical electrode comprises: a proximal end configured to receive electrosurgical energy from an electrosurgical instrument; a distal end opposite the proximal end; and a cutting electrode extending from the proximal end to the distal end for cutting tissue using the electrosurgical energy received from the electrosurgical instrument; a coagulation electrode portion extending from the proximal end to the distal end for coagulating tissue using the electrosurgical energy received from the electrosurgical instrument; an insulator between the cutting electrode and the coagulation electrode; a first side extending between the proximal end and the distal end; a second side extending between the proximal end and the distal end; a first edge at a first lateral connection between the first side and the second side; a second edge at a second lateral connection between the first side and the second side; and Equipped with the first side is on one side of an intermediate surface extending through the first edge and the second edge, and the second side is on the other side of the intermediate surface; the cutting electrode portion includes the first edge and the coagulation electrode portion includes the second edge, the first edge being thinner than the second edge; The electrosurgical instrument comprises: a housing having a distal end and a proximal end; at least one electrical conductor configured to couple the electrosurgical electrode to an electrosurgical generator; a receptacle located at the distal end configured to couple to the proximal end of the electrosurgical electrode; at least one user input device configured to select between a cut surgery mode and a coagulation surgery mode; It is equipped with in the cutting surgical mode, the electrosurgical instrument delivers the electrosurgical energy from the at least one electrical conductor to the cutting electrode portion of the electrosurgical electrode and not to a coagulation electrode portion of the electrosurgical electrode; An electrosurgical system, wherein in the coagulation surgical mode, the electrosurgical instrument is configured to supply the electrosurgical energy from the at least one electrical conductor to at least the coagulation electrode portion of the electrosurgical electrode.

2. The electrosurgical system of claim 1 , wherein a surface area of ​​the cutting electrode portion is less than a surface area of ​​the coagulation electrode portion.

3. The electrosurgical system of claim 1 , wherein the cutting electrode portion is spaced from the coagulation electrode portion along the entire length of the electrosurgical electrode between the proximal and distal ends.

4. The electrosurgical system of claim 1 , wherein the insulator comprises a material selected from the group consisting of plastic, ceramic, and enamel.

5. An electrosurgical system as described in any one of claims 1 to 4, wherein the electrosurgical electrode is coupled to a receptacle by a non-removable connection.

6. The at least one user input device: a first user input device operable to cause the electrosurgical generator to supply the electrosurgical energy to the cutting electrode; a second user input device operable to cause the electrosurgical generator to supply the electrosurgical energy to the coagulation electrode.

7. The at least one conductor is a first electrical conductor configured to couple the cutting electrode to the electrosurgical generator; The electrosurgical system of claim 1 , comprising: a second electrical conductor configured to couple the coagulation electrode portion to the electrosurgical generator.

8. further comprising an electrosurgical generator coupled to the electrosurgical instrument and configured to supply electrosurgical energy to the electrosurgical instrument; the electrosurgical generator comprising: measuring at least one electrical property through tissue between the cutting electrode and the coagulation electrode; The electrosurgical system of claim 1 , wherein the electrosurgical electrode is configured to determine a characteristic of tissue to which the electrosurgical energy has been applied based on the at least one of the electrical characteristics.

9. the electrosurgical generator is configured to vary at least one of a power or a waveform of the electrosurgical energy delivered to the electrosurgical instrument based on at least one of a resistance or a voltage measured between the cutting electrode and the coagulation electrode; the electrical characteristic is at least one electrical characteristic selected from the group consisting of impedance, voltage, capacitance, and inductance; The electrosurgical system of claim 8, wherein the characteristic of the tissue is at least one characteristic selected from the group consisting of impedance of the tissue, water content of the tissue, density of the tissue, fat content of the tissue, and temperature of the tissue.

10. The electrosurgical system of claim 1 , wherein the intermediate surface extends through the insulator, the insulator extending entirely from the first side to the second side.

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