Electrosurgical Bipolar Pencil

Abstract

The electrosurgical bipolar surgical instrument includes an elongate shaft extending along a central axis between a proximal end and a distal end, an outer electrode extending from the distal end, an inner electrode extending within the elongate shaft and into the outer electrode, and an intermediate insulating member disposed between the outer electrode and the inner electrode.

Description

[Technical Field]

[0001] (Priority Claim) This application claims the benefit of, and hereby claims the benefit of priority to, U.S. Provisional Patent Application No. 63 / 434,595, filed December 22, 2022, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally, but not exclusively, to systems, instruments and methods relating to electrosurgery. More particularly, the present application relates to electrosurgical instruments having two poles. [Background technology]

[0003] Electrosurgery is a surgical technique that uses high frequency electrical current to precisely ablate, coagulate, desiccate, and discharge tissue. Improvements in electrosurgical techniques and equipment are ongoing.

[0004] Electrosurgery is a surgical technique that uses high-frequency electrical current to precisely ablate, coagulate, desiccate, and discharge tissue. Electrosurgery offers several advantages over conventional surgery, including precise control of the amount of tissue destruction, the ability to coagulate blood vessels and minimize bleeding, and reduced thermal injury to surrounding tissue. However, electrosurgery has several limitations, including the potential for electrical burns and charring of tissue, as well as the risk of electrical interference with electronic devices such as pacemakers. There are several types of electrosurgery, including monopolar and bipolar electrosurgery.

[0005] Monopolar electrosurgery may be used to remove or seal portions of tissue during open surgery, such as for biopsies or to control bleeding. In monopolar electrosurgery, electrical current may be delivered through a handheld device called an electrocautery pen, monopolar forceps, or monopolar pencil. The electrical current may return to the electrosurgical generator via a grounding pad placed on the patient's skin. Monopolar electrosurgery offers several advantages, including the ability to quickly and effectively cut or coagulate tissue with minimal bleeding. However, monopolar electrosurgery may also have several potential drawbacks, such as the risk of electrical current passing through unintended body areas and the risk of thermal damage to surrounding tissue. Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors have recognized, among other things, that monopolar electrosurgery has drawbacks.

[0007] One of the drawbacks of monopolar electrosurgery is patient burns. For example, the current passing through the patient's body can damage vital organs. Serious internal burns can occur. The estimated incidence of such burns is 3.6 per 1,000 laparoscopic procedures.

[0008] Another drawback of monopolar electrosurgery is improper placement of the grounding pad. For example, the return electrode (pad) may be placed close to the surgical site to minimize the current path. Improper placement can result in burns at the pad site. Therefore, pad placement requires a high degree of skill and experience.

[0009] Another drawback of monopolar electrosurgery is lateral heat spread. For example, the device may undesirably heat the tissue surrounding the active electrode. Monopolar devices may generate more heat during coagulation than comparable bipolar or ultrasonic devices. Therefore, careful manipulation of the device is required.

[0010] Another drawback of monopolar electrosurgery is direct heat dissipation. For example, the active electrode may contact structures with narrow pedicles or narrow adhesion bands. Increased current density in such remote, narrow areas can cause unintended burns. The use of monopolar instruments in these areas can be avoided, resulting in limited use.

[0011] The present invention may provide a solution to these and other problems by providing bipolar electrosurgical systems, instruments and methods.

[0012] Bipolar electrosurgery is similar to monopolar electrosurgery in that it uses two electrodes. However, rather than placing one electrode remotely from the instrument, such as a pad grounded to the patient's skin, both electrodes can be located on the instrument itself. In traditional bipolar surgery, the current is delivered through a pair of small, insulated jaws attached to a forceps. Bipolar electrosurgery offers several advantages over monopolar electrosurgery.

[0013] One advantage of bipolar surgery is that it reduces the risk of electrical current passing through the patient's body. For example, because the electrical current is contained within the bipolar forceps and does not pass through the body, there is less risk of electrical current passing through unintended areas of the body, thereby minimizing the risk of tissue damage and other complications.

[0014] Another benefit is a reduced risk of burns. For example, the current used in bipolar electrosurgery is more contained within the bipolar forceps and is therefore less likely to cause burns to surrounding tissue. This makes them a safer option when used near sensitive structures such as nerves and blood vessels.

[0015] Another advantage is its suitability for laparoscopic procedures, for example, bipolar electrosurgery is suitable for use in laparoscopic procedures because the current is contained within the laparoscopic instruments and may not pass through the abdominal wall.

[0016] Another advantage is better control over the target area, thereby preventing damage to other sensitive tissues.

[0017] Another advantage is that the risk of burns to the patient is reduced.

[0018] Another advantage is that it is suitable for use in patients with implanted devices, for example, the containment of current helps prevent short circuits and malfunctions in the implanted devices.

[0019] Generally, existing bipolar instruments may provide coagulation capabilities but may not be able to provide tissue cutting.

[0020] The bipolar devices of the present disclosure can provide tissue cutting. Additionally, the bipolar devices of the present disclosure can provide improved access to lesions over existing bipolar devices. Additionally, the bipolar devices of the present disclosure can provide significantly improved ablation and cutting performance compared to existing bipolar devices.

[0021] The electrosurgical bipolar pencil of the present disclosure may include a needle-shaped active inner electrode insulated with ceramic and a return electrode surrounding the ceramic. The active inner electrode and the return electrode may be connected within a handle. The handle may lead the active inner electrode and the return electrode to a radio frequency (RF) generator. The ergonomic configuration, e.g., appearance and shape, of the electrosurgical bipolar pencil may be similar to that of a conventional monopolar electrosurgical pen. The return electrode may have a dome shape at the end of the electrosurgical bipolar pencil to facilitate contact with the tissue surrounding the inner electrode. In some examples, the electrosurgical bipolar pencil may reciprocate the active inner electrode or the outer electrode to provide adequate contact surface fineness between the active inner electrode and the return electrode. The shape and position of the inner and outer electrodes may facilitate plasma formation at the inner electrode using a small amount of electrical energy.

[0022] As an example, an electrosurgical bipolar surgical instrument may include an elongate shaft extending along a central axis between a proximal end and a distal end, an outer electrode extending from the distal end, an inner electrode extending from the interior of the elongate shaft to the interior of the outer electrode, and an intermediate insulating member disposed between the outer electrode and the inner electrode. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view of an electrosurgical bipolar pencil with an outer dome electrode, an intermediate insulating layer, and an inner electrode pin, configured for direct connection to a generator and foot switch or for standalone use. [Figure 2A] FIG. 2A is a perspective view of an electrosurgical bipolar pencil with an outer dome electrode, an intermediate insulating layer, and an inner electrode pin configured for use with a reusable handpiece and having a disposable tip for connection to a generator and foot switch. [Figure 2B] FIG. 2B is an enlarged view of the tip assembly of the electrosurgical bipolar pencil of FIG. 2A showing the outer dome electrode, the middle insulating layer, and the inner electrode pin. [Figure 3A] FIG. 3A is a perspective view of the front end of an electrosurgical bipolar pencil with a shaft, an outer dome electrode, a middle insulating layer, and a fixed inner electrode. [Figure 3B] FIG. 3B is a side cross-sectional view of the electrosurgical bipolar pencil of FIG. 3A. [Figure 4A] FIG. 4A is a side schematic view of the electrosurgical bipolar pencil of FIG. 3A with a fixed inner electrode positioned away from the tissue. [Figure 4B] FIG. 4B is a side schematic view of the electrosurgical bipolar pencil of FIG. 3A with a fixed inner electrode positioned for insertion into tissue. [Figure 5A] FIG. 5A is a side perspective view of an electrosurgical bipolar pencil with a shaft, an outer dome electrode, an intermediate insulating layer, and a movable inner electrode in an extended state. [Figure 5B]FIG. 5B is a side perspective view showing the movable inner electrode of the electrosurgical bipolar pencil of FIG. 5A in a retracted state. [Figure 6A] FIG. 6A is a perspective cross-sectional view of an electrosurgical bipolar pencil with a shaft, an outer dome electrode, an intermediate insulating layer, and a movable inner electrode in an extended state. [Figure 6B] 6B is a perspective cross-sectional view of the electrosurgical bipolar pencil of FIG. 6A showing the movable inner electrode in a retracted state. [Figure 7A] FIG. 7A is a side cross-sectional view of the electrosurgical bipolar pencil of FIGS. 5A-6B in an extended position relative to tissue. [Figure 7B] FIG. 7B is a side cross-sectional view of the electrosurgical bipolar pencil of FIGS. 5A-6B in a retracted position relative to tissue. [Figure 8A] FIG. 8A is a side perspective view of an electrosurgical bipolar pencil having a movable outer dome electrode in an extended state. [Figure 8B] FIG. 8B is a side perspective view of an electrosurgical bipolar pencil having a movable outer dome electrode in a retracted state. [Figure 9] FIG. 9 is a side cross-sectional view of the electrosurgical bipolar pencil of FIGS. 8A and 8B showing the spring mechanism connecting the outer dome electrode to the shaft. [Figure 10A] FIG. 10A is a side view of the electrosurgical bipolar pencil of FIGS. 8A and 8B with a movable outer dome electrode extended against tissue. [Figure 10B] FIG. 10B is a side view of the electrosurgical bipolar pencil of FIGS. 8A and 8B with the movable outer dome electrode retracted relative to tissue. [Figure 11A] FIG. 11A is a side perspective view of an electrosurgical bipolar pencil with a shaft, an outer dome electrode, an intermediate insulating layer, and an extended, reciprocating inner electrode. [Figure 11B] FIG. 11B is a side perspective view of the electrosurgical bipolar pencil of FIG. 11A showing the reciprocating inner electrode in a retracted state. [Figure 12A]FIG. 12A is a perspective cross-sectional view of an electrosurgical bipolar pencil with a shaft, an outer dome electrode, an intermediate insulating layer, and an extended, reciprocating inner electrode. [Figure 12B] FIG. 12B is a perspective cross-sectional view of the electrosurgical bipolar pencil of FIG. 12A showing the reciprocating inner electrode in a retracted state. [Figure 13A] FIG. 13A is a side cross-sectional view of the reciprocating mechanism of the electrosurgical bipolar pencil of FIGS. 11A-12B with the drive shaft in a retracted position. [Figure 13B] FIG. 13B is a side cross-sectional view of the reciprocating mechanism of FIG. 13A with the drive shaft in an extended position. [Figure 14] FIG. 14 is a side cross-sectional view of a reciprocating mechanism suitable for the electrosurgical bipolar pencil of FIGS. 11A-12B. [Figure 15A] FIG. 15A is an end view of an electrosurgical bipolar pencil with an outer dome electrode, an intermediate insulating layer, and a movable inner electrode with a pin tip. [Figure 15B] FIG. 15B is a side view showing the pin tip of the electrosurgical bipolar pencil of FIG. 15A extended beyond the outer dome electrode. DETAILED DESCRIPTION OF THE INVENTION

[0024] FIG. 1 is a perspective view of a stand-alone electrosurgical pencil 100. Electrosurgical pencil 100 may include a handpiece 102, a shaft 104, and a tip 106. Handpiece 102 may include buttons 108A, 108B, and 108C. Tip 106 may include an outer dome electrode 110, an intermediate insulating layer 112, and an inner electrode pin 114. Electrosurgical pencil 100 may be constructed as a disposable device using less expensive components compared to reusable devices. Disposable devices have the advantage that, for example, the device does not need to be cleaned, disinfected, or sterilized, eliminating the risk of contamination and infection associated with reused devices.

[0025] Electrosurgical pencil 100 may include an instrument configured to deliver electrical energy to cut and ablate tissue. In the illustrated embodiment, electrosurgical pencil 100 includes a self-contained instrument including a battery 116 within handpiece 102 to supply electrical energy to inner electrode pin 114 at tip 106. Additionally, handpiece 102 may include an electric motor 118 for generating a rotary axial force suitable for use with reciprocating mechanism 560 of FIGS. 13A and 13B and reciprocating mechanism 600 of FIG. 14 . In additional embodiments, electrosurgical pencil 100 may be configured to connect to generator 152 of FIG. 2 using appropriate wiring and cabling, thereby eliminating the need for an internal battery. Button 108A may include an on / off switch and thus be used to activate electrical energy at tip 106. Buttons 108A and 108C may be used to control the function (e.g., waveform) and magnitude (e.g., voltage) of the electrical energy delivered to tip 106, respectively. As described herein, electrical energy can be supplied to the inner electrode pin 114, pass through tissue when the tip 106 contacts the tissue, and return to the electrosurgical pencil 100 through the outer dome electrode 110. In this manner, the electrosurgical pencil 100 can comprise an electrosurgical bipolar pencil. The intermediate insulating layer 112 can be used to electrically insulate the inner electrode pin 114 from the outer dome electrode 110. The distal tip of the inner electrode pin 114 can extend axially distally beyond the intermediate insulating layer 112 and contact the target tissue. The outer dome electrode 110 can contact the tissue surrounding the target tissue. In additional examples, the tip 106 can be configured as a detachable tip, such that the tip 106 is disposable and the remainder of the electrosurgical pencil 100 is reusable.

[0026] Details of the tip 106 are described below. Specifically, the tip 106 can be configured according to any of the embodiments described herein. For example, the tip 106 can be configured with a fixed inner electrode pin 114, a spring-loaded inner electrode pin 114, a reciprocating inner electrode pin 114, a fixed outer dome electrode 110, a spring-loaded outer dome electrode 110, or a reciprocating outer dome electrode 110.

[0027] FIG. 2A is a perspective view of an electrosurgical pencil 150 for use in a surgical system. Electrosurgical pencil 150 can be used with a generator 152 and a foot switch system 154. Generator 152 can include a fluid input at manifold 156. Electrosurgical pencil 150 can be configured as a disposable instrument using less expensive components compared to reusable instruments. Generator 152 and foot switch system 154 can be configured as reusable components. The components in FIG. 2A are not necessarily drawn to scale relative to each other. In additional embodiments, tip 176 can be configured as a detachable tip, where tip 176 is disposable and the remainder of electrosurgical pencil 150 is reusable.

[0028] Foot switch system 154 can be connected to generator 152 via cable 160, and generator 152 can be connected to electrosurgical pencil 150 via cable 162 and handpiece 163. Foot switch system 154 can be configured to control the operation of manifold 156 and electrosurgical pencil 150. Fluid lines 164 for fluid input and output connect manifold 156 to a source of pressurized fluid (not shown). Aspiration lines 166 for aspiration input and output connect manifold 156 to a vacuum source (not shown). Foot switch system 154 can include pedal 168A for controlling a first function of electrosurgical pencil 150 (e.g., a cutting function), pedal 168B for controlling a second function of electrosurgical pencil 150 (e.g., a coagulation function), and pedal 168C for controlling a third function of manifold 156 (e.g., a flush). Foot switch system 154 may include a switch 170A for controlling a fourth function (e.g., cutting mode) of electrosurgical pencil 150, a switch 170B for controlling a fifth function (e.g., flow rate) of electrosurgical pencil 150, and a switch 170C for controlling a sixth function (e.g., mode) of manifold 156.

[0029] Electrosurgical pencil 150 may include a plug 172, a shaft 174, and a tip 176. Plug 172 of electrosurgical pencil 150 may be inserted into a socket 178 of handpiece 163. Electrical contacts on plug 172 connect with corresponding electrical contacts in socket 178, transmitting power from generator 152 to tip 176.

[0030] FIG. 2B is an enlarged view of the tip 176 of the electrosurgical pencil 150 of FIG. 2A , showing the outer dome electrode 180, the middle insulating layer 182, and the inner electrode pin 184. Details of the tip 176 are described below. Specifically, the tip 176 can be configured according to any of the embodiments described herein. For example, the tip 176 can be configured with a fixed inner electrode pin 184, a spring-loaded inner electrode pin 184, a reciprocating inner electrode pin 184, a fixed outer dome electrode 180, a spring-loaded outer dome electrode 180, or a reciprocating outer dome electrode 180. As described herein, electrical energy can be supplied to the inner electrode pin 184, pass through tissue when the tip 176 contacts tissue, and return to the electrosurgical pencil 150 at the outer dome electrode 180. In this manner, the electrosurgical pencil 150 can comprise an electrosurgical bipolar pencil.

[0031] Figure 3A is a perspective view of the front end of electrosurgical pencil 200, including tip assembly 202 and shaft 204. Figure 3B is a side cross-sectional view of electrosurgical pencil 200 of Figure 3A. Figures 3A and 3B will be discussed simultaneously. In some embodiments, tip assembly 202 can be used with shaft 104 and shaft 174 of Figures 1 and 2A.

[0032] The tip assembly 202 may include an outer dome electrode 206, an intermediate insulating layer 210, and an inner electrode 212. In the embodiment of Figures 3A and 3B, the inner electrode 212 may include a fixed electrode configured to extend a fixed distance along the axis AA from the intermediate insulating layer 210.

[0033] The shaft 204 may include a tubular body 214 to which the outer dome electrode 206 can be attached. The tubular body 214 may be covered on the outside by a sheath 216 and include an internal passageway 218 ( FIG. 3B ). The outer dome electrode 206 may include a tubular body 220 having an internal passageway 222 ( FIG. 3B ) coaxially aligned with the passageway 218 of the shaft 204. In some embodiments, the tubular body 220 may comprise a one-piece body. However, in other embodiments in which the tip assembly 202 is removable, the distal portion of the tubular body, including the exterior surface 224, may be separable from the proximal portion. In some embodiments, the distal portion may be attached to the proximal portion by any suitable connection means, such as an interference fit connection, the use of a fastener such as a set screw, or the use of a detent mechanism. Additionally, the separable distal portion of the insulating layer 210 may be attached to a removable portion of the tubular body 220, allowing the two parts to be attached and detached together. The outer dome electrode 206 may include an exterior surface 224 and an end face 226. The interior passage 222 of the outer dome electrode 206 may receive the intermediate insulating layer 210. The intermediate insulating layer 210 may include a cylindrical body 228 having an end face 230 and an interior passage 232 (FIG. 3B). The inner electrode 212 may be disposed within the interior passage 232 and include an elongated shaft 234 and a pointed tip 236. In the embodiment of FIGS. 3A and 3B, the inner electrode 212 may be secured within the interior passage 232 such that the pointed tip 236 is secured to the exterior of the intermediate insulating layer 210. In some embodiments, the inner electrode 212 may be held in place via an interference fit with the interior passage 232. In some embodiments, the inner electrode 212 may be metallurgically bonded in place via welding or soldering. In some embodiments, the inner electrode 212 may be mechanically held in place via a fastener such as a set screw. In this manner, the setscrew is accessible from the outside of electrosurgical pencil 200 and allows the user to adjust the distance that sharpened tip 236 extends beyond end face 226 .

[0034] The shaft 204 can extend proximally and connect to a handpiece, as described herein. The shaft 204 is hollow and can include conductors for supplying current from an electrical generator (e.g., battery 116 in FIG. 1 or generator 152 in FIG. 2A ) to the inner electrode 212 and receiving current from the outer dome electrode 206 (or vice versa). The tubular body 214 can have an exterior cross-sectional shape to facilitate insertion into tissue, provide interior space for components of the electrosurgical pencil 200, and provide strength to the shaft 204. In embodiments, the tubular body 214 can have a circular, triangular, rectangular, or square cross-sectional profile. In the illustrated embodiment, the tubular body 214 has a rounded pyramidal shape with three flat surfaces joined by three rounded edge surfaces. The tubular body 214 can provide support for the outer dome electrode 206, as described below, or can be of integral or unitary construction. The tubular body 214 can be made of a variety of materials to provide desirable structural support and electrical conductivity characteristics. In embodiments where the tubular body 214 is integral with the outer dome electrode 206, the tubular body 214 can be conductive. In embodiments where the tubular body 214 is separate from the outer dome electrode 206, the tubular body 214 can be insulating. In embodiments, the tubular body 214 can be fabricated from steel, stainless steel alloys, aluminum, aluminum alloys, other metals and metal alloys, ceramics, glass, fiberglass, plastics, polymers, and other materials. The tubular body 214 can be covered with a sheath 216 to ensure electrical insulation, e.g., to prevent electrical current from passing into or out of the tubular body 214. In embodiments, the sheath 216 can include a polymeric heat shrink wrap. The sheath 216 can be omitted in embodiments, such as when the tubular body 214 is separate from the outer dome electrode 206.

[0035] The inner electrode 212 extends proximally from what is shown in FIG. 3B and can be connected to a wire or other suitable connector that can be connected to a power source, such as the battery 116 ( FIG. 1 ) or the generator 152 ( FIG. 2A ). The inner electrode 212 can be covered within the tubular body 214 by a sheath 244 to provide electrical insulation. In some embodiments, the sheath 244 can include a polymeric heat-shrink wrap. The inner electrode 212 can be exposed at a distal or other demarcation point of the tubular body 214 to allow electrical energy to exit or pass through the inner electrode 212. The portion of the inner electrode 212 not covered by the sheath 244 and proximal to the end face 230 can be surrounded by an intermediate insulating layer 210. The pointed tip 236 can be exposed, for example, without being covered by the sheath 244, the intermediate insulating layer 210, or the outer dome electrode 206. The inner electrode 212 can be fabricated from a variety of conductive materials, such as steel, aluminum, copper, or alloys thereof.

[0036] The elongated shaft 234 can include a cylindrical body, and the pointed tip 236 can include a conical body. In some embodiments, the elongated shaft 234 can include a unitary body. However, in other embodiments in which the tip assembly 202 is removable, the distal portion of the elongated shaft 234, including the pointed tip 236, can be separated from the proximal portion. In the embodiment of FIG. 3B, the elongated shaft 234 can include a step at the end of the sheath 244. However, such a step can be omitted. The elongated shaft 234 can extend through the passageway 218 of the tubular body 214 and the interior passageway 222 of the outer dome electrode 206. Similarly, the elongated shaft 234 can extend through the interior passageway 232 intermediate the intermediate insulating layer 210. In some embodiments, the passageway 218, the interior passageway 222, the interior passageway 232, and the elongated shaft 234 can be coaxial along the longitudinal axis AA. However, the elongated shaft 234 can be offset from the longitudinal axis AA. The distal end of the cylindrical body including the elongated shaft 234 can be located approximately at the end surface 230 such that the base of the cone forms a pointed tip 236 at the junction of the cylindrical body and is approximately flush with the end surface 230. As an example, the end surface 230 can be recessed into the outer dome electrode 206 relative to the end surface 226. Thus, the entire taper of the pointed tip 236 can be located outside the cylindrical body 228 of the intermediate insulating layer 210. However, as an example, the base of the cone forming the pointed tip 236 can be located within or even outside the internal passageway 232. The shape of the pointed tip 236 is described in more detail below.

[0037] Intermediate insulating layer 210 may be disposed between inner electrode 212 and outer dome electrode 206 to prevent electrical conduction. By way of example, intermediate insulating layer 210 may be made of an insulating material such as ceramic, glass, plastic, fiberglass, wood, etc. to prevent electrical contact between inner electrode 212 and outer dome electrode 206. In certain embodiments, intermediate insulating layer 210 is made of ceramic to provide sufficient insulation for the currents and power typically associated with electrosurgical equipment.

[0038] The cylindrical body 228 of the intermediate insulating layer 210 can surround the elongated shaft 234 within the interior passage 222 of the outer dome electrode 206 and partially within the passage 218 of the tubular body 214 of the shaft 204. The cylindrical body 228 can stabilize the elongated shaft 234 and prevent or inhibit radial movement relative to the longitudinal axis AA. The cylindrical body 228 can be connected to or integral with an enlarged cylindrical portion 238. The enlarged cylindrical portion 238 can be positioned within the passage 218 of the tubular body 214 of the shaft 204. The enlarged cylindrical portion 238 can be positioned against a step 240 in the tubular body 220 of the outer dome electrode 206. The intermediate insulating layer 210 can be secured within the passage 218 via a flange 242 of the shaft 204. The enlarged cylindrical portion 238 can stabilize the inner electrode 212 within the passage 218 and inhibit radial movement relative to the longitudinal axis AA. In embodiments in which tip assembly 202 is removable, cylindrical body 228 can be configured to separate from enlarged cylindrical portion 238. For example, cylindrical body 228 can simply contact enlarged cylindrical body 228 and be secured by engagement between tubular body 220 and tubular body 214, or can be inserted into a socket within the enlarged cylindrical body.

[0039] The outer dome electrode 206 can extend from the tubular body 214. As an example, the outer dome electrode 206 can be integral or unitary with the tubular body 214 to form an extension of the tubular body 214. As an example, the outer dome electrode 206 can be attached to the tubular body 214 via a threaded connection, a welded connection, or a fastener. The outer dome electrode 206 can be made of a conductive material, such as stainless steel, aluminum, copper, or alloys thereof. The outer dome electrode 206 can be connected to wiring or other suitable connectors that can communicate with a power source, such as the battery 116 ( FIG. 1 ) or the generator 152 ( FIG. 2A ).

[0040] The outer dome electrode 206 can have a shape that facilitates creating a large contact area with tissue when the tip assembly 202 is pressed into the tissue. As an example, the outer dome electrode 206 can have a truncated cone shape to form the end face 226. In such an example, the outer dome electrode 206 can have a circular cross-sectional profile that decreases in diameter between the tubular body 214 and the end face 226. As an example, the outer dome electrode 206 can have a pyramidal shape. In such an example, the outer dome electrode 206 can have a triangular cross-sectional profile that decreases in diameter between the tubular body 214 and the end face 226. In the illustrated example, the outer dome electrode 206 can have a rounded pyramidal shape with three flat faces joined by three rounded edge faces. The three flat faces can have a parabolic shape, as shown in FIG. 3B. Thus, when the outer dome electrode 206 is pressed into biological tissue, the tissue contacts the face of the outer dome electrode 206, forming good electrical contact, allowing current flowing from the inner electrode 212 to pass through the tissue and return to the outer dome electrode 206. The facets also provide a large surface area for contacting biological tissue.

[0041] 3A and 3B, inner electrode 212 can be stationary relative to outer dome electrode 206. Thus, sharp tip 236 can protrude from outer dome electrode 206 beyond end face 226, beyond end face 230, and beyond intermediate insulating layer 210.

[0042] Figure 4A is a side schematic view of the electrosurgical pencil 200 of Figure 3B with the inner electrode 212 positioned away from the tissue 250. Figure 4B is a side schematic view of the electrosurgical pencil 200 of Figure 4B with the inner electrode 212 in a position inserted into the tissue 250.

[0043] During use, the electrosurgical pencil 200 can be inserted into biological tissue and guided toward target tissue to be treated with electrical therapy, e.g., cauterization, cutting, etc. The electrosurgical pencil 200 can be configured to not provide electrical output to the inner electrode 212 while being guided toward the target tissue, such as by not pressing button 108A (FIG. 1). The target tissue may typically be surrounded by other tissue, whether or not to be treated. The outer dome electrode 206 can push surrounding tissue away from the pointed tip 236 until the surgeon or user is ready to contact the target tissue. Once the target tissue site within the biological tissue is reached, the pointed tip 236 can be pushed into the target tissue to perform the treatment. Electrical activation of the pointed tip 236 can occur before, during, or after insertion of the pointed tip 236 into the target tissue, such as by pressing button 108A. Current can flow out of the pointed tip 236, into the tissue 250, and back to the outer dome electrode 206. The pointed shape of the sharp tip 236 concentrates the electrical current output from the sharp tip 236 in a focused area. This allows for greater electrosurgical power, such as cauterizing, cutting, or ablating power, to be utilized from a smaller current compared to a tip that does not concentrate electrical energy like the sharp tip 236. The surface of the outer dome electrode 206 can be positioned in close proximity to the sharp tip 236 to provide a short path for the current to return to the electrosurgical pencil 200. In particular, the end face 226 can be separated from the inner electrode 212 by the thickness of the intermediate insulating layer 210. Furthermore, the outer surface 224 of the outer dome electrode 206 can collect other currents in close proximity to the inner electrode 212, such as leakage current from the inner electrode 212, for return to the electrosurgical pencil 200. Therefore, the ratio of the surface area of ​​the outer dome electrode 206 that contacts tissue to the surface area of ​​the inner electrode 212 that contacts tissue is high, which facilitates cutting at the inner electrode 212 and discharging at the outer dome electrode 206. Further description of the pointed tip 236, intermediate insulating layer 210, and outer dome electrode 206 is provided below with reference to Figures 15A and 15B.

[0044] Figure 5A is a perspective side view of electrosurgical pencil 300 in an extended state, including shaft 302 and tip assembly 304. Figure 5B is a perspective side view of electrosurgical pencil 300 in a retracted state, including shaft 302 and tip assembly 304. Tip assembly 304 may include an outer dome electrode 306, an intermediate insulating layer 308, and a movable inner electrode 310. Figure 6A is a perspective cross-sectional view of electrosurgical pencil 300 of Figure 5A with movable inner electrode 310 in an extended state. Figure 6B is a perspective cross-sectional view of electrosurgical pencil 300 of Figure 6A with movable inner electrode 310 in a retracted state. Figures 5A through 6B will be discussed simultaneously.

[0045] 5A-6B, the movable inner electrode 310 may comprise a movable electrode configured to extend from the intermediate insulating layer 308 (FIGS. 5A and 6A) and retract back into the intermediate insulating layer 308 (FIGS. 5B and 6B). The retraction or retraction of the pointed tip 336 (FIG. 7A) into the interior passage 332 is advantageous in reducing the likelihood of plasma formation on the outer dome electrode 306 by ensuring that the outer dome electrode is in contact with a large surface area of ​​tissue when the pointed tip 336 is electrically activated.

[0046] As an example, electrosurgical pencil 300 may include one or more locks for securing inner electrode 312 in the extended state ( FIG. 7A ) or the retracted state ( FIG. 7B ). The lock may include a set screw (not shown) extending into tubular body 314 to engage proximal portion 350 of inner electrode 312. The set screw may press against proximal portion 350 to prevent axial displacement. As an example, electrosurgical pencil 300 may include a lever (not shown) extending from tubular body 314 through a slot to allow a user to manually move inner electrode 312 axially.

[0047] The shaft 302 may include a tubular body 314 to which the outer dome electrode 306 is attached. The tubular body 314 may be externally covered by a sheath 316 and may include a passageway 318 therein. The outer dome electrode 306 may include a tubular body 320 having an internal passageway 322 coaxially aligned with the passageway 318 in the shaft 302. The outer dome electrode 306 may include an exterior surface 324 and an end face 326. The internal passageway 322 of the outer dome electrode 306 may house an intermediate insulating layer 308. The intermediate insulating layer 308 may include a cylindrical body 328 having an end face 330 and an internal passageway 332. The inner electrode 312 is disposed within the internal passageway 332 and may include an elongated shaft 334 and a pointed tip 336.

[0048] The intermediate insulating layer 308 may further include a proximal portion 340 located proximal to the cylindrical body 328. The proximal portion 340 may include an interior chamber 342 having a larger diameter than the interior passageway 332. The proximal portion 340 may include a port 344 that allows the inner electrode 312 to enter the interior chamber 342. The intermediate insulating layer 308 may be secured within the passageway 318 via a flange 346 of the shaft 302.

[0049] The inner electrode 312 may further include a proximal portion 350 and a flange 352. The proximal portion 350 may include a sheath 354. A biasing element 360 may be disposed about the proximal portion 350 proximal to the flange 352.

[0050] Electrosurgical pencil 300 can be configured to operate similarly to electrosurgical pencil 200 of Figures 3A and 3B. For example, inner electrode 312 can be energized to deliver current to target tissue, outer dome electrode 306 can provide a current return path, and intermediate insulating layer 308 can electrically isolate inner electrode 312 from outer dome electrode 306. However, as described above, rather than movable inner electrode 310 being fixed by mechanical or metallurgical means, movable inner electrode 310 can be configured to slide within intermediate insulating layer 308. Notably, movable inner electrode 310 can include a flange 352 configured to engage internal chamber 342, as described in detail with reference to Figures 7A and 7B.

[0051] Figure 7A is a side cross-sectional view of electrosurgical pencil 300 of Figures 5A-6B in an extended position relative to tissue 370. Figure 7B is a side cross-sectional view of electrosurgical pencil 300 of Figures 5A-6B in a retracted position relative to tissue 370.

[0052] Similar to what was described with reference to electrosurgical pencil 200 and FIGS. 4A and 4B , electrosurgical pencil 300 can be navigated to target tissue, such as tissue 370. Electrosurgical pencil 300 can be navigated with movable inner electrode 310 in an extended state, as shown in FIG. 7A . In the extended state, movable inner electrode 310 is movable distally, to the right of FIG. 7A , with flange 352 contacting the distal end of internal chamber 342. Movable inner electrode 310 can be biased distally by biasing element 360. Biasing element 360 can press against the proximal end of internal chamber 342. By way of example, biasing element 360 can be other biasing elements, such as a leaf spring, a bellows spring, or the like. In additional examples, one or more of biasing elements 360 can be disposed around movable inner electrode 310. Examples include other biasing elements such as leaf springs, bellows springs, wave washers / washer springs, etc. Biasing element 360 can urge movable inner electrode 310 with sufficient force to secure movable inner electrode 310 during operation of electrosurgical pencil 200. However, the force of biasing element 360 can be set such that movable inner electrode 310 is urged proximally, e.g., to the left in FIG. 7A , when pointed tip 336 is engaged with tissue by a user.

[0053] As shown in FIG. 7B , when the pointed tip 336 engages the tissue 370, the movable inner electrode 310 is pushed proximally, i.e., to the left in FIG. 7B . The force of the tissue 370 pushing against the pointed tip 336 compresses the biasing element 360 via movement of the flange 352. The pointed tip 336 can be fully retracted into the internal passage 332 so that it is located proximal to the distal end face 326. In an example, once the pointed tip 336 is retracted into the internal passage 332, the biasing element 360 is fully compressed, preventing further proximal movement of the movable inner electrode 310. It may be advantageous for the distal-most point of the pointed tip 336 to be flush with the end face 326 so that the shortest distance between the movable inner electrode 310 and the outer dome electrode 306 is located at the distal-most point of the pointed tip 336. Therefore, the current emitted from the pointed tip 336 can pass through only a small portion of the tissue 370, such as the area where electrotherapy is to be administered. The administered current is discharged before returning to the outer dome electrode 306, thereby eliminating or reducing the possibility of stray current flow to undesired tissue areas.

[0054] Furthermore, by retracting the sharp tip 336 into the inner passage 332, the outer dome electrode 306 can be inserted deeper into tissue, allowing a greater portion of the outer dome electrode 306 to contact tissue before the movable inner electrode 310 is activated, thereby limiting the ability to form plasma on the outer dome electrode 306. Furthermore, the less the movable inner electrode 310 is exposed to tissue, the greater the likelihood of plasma formation on the movable inner electrode 310. As previously mentioned, to promote plasma formation at the intended location, a high ratio of the surface area of ​​the return electrode (e.g., the outer dome electrode 306) in contact with tissue to the surface area of ​​the active electrode (e.g., the movable inner electrode 310) in contact with tissue may be desirable. Thus, retracting the sharp tip 336 increases this ratio. In other words, contacting a large amount of tissue with the outer dome electrode 306 can reduce current density and plasma generation potential, while contacting only a small amount of tissue with the movable inner electrode 310 can increase current density and plasma generation potential. In FIG. 7B, the ratio of the exposed area of ​​the sharp tip 336 to the exposed area of ​​the outer dome electrode 306 is higher than in FIG. 7A, which allows the configuration of FIG. 7B to better form a plasma and cut tissue.

[0055] However, if the size of the sharp tip 336 that contacts the tissue is too small, the ability to cut the tissue may be reduced. Therefore, in the present disclosure, the shape of the sharp tip 336 and the shape of the outer dome electrode 306 are configured to increase the proportion of tissue that can contact the outer dome electrode 306 and the sharp tip 336. Furthermore, the position of the sharp tip 336 relative to the outer dome electrode 306 can be adjusted to adjust the ratio. Such features are described with reference to Figures 15A and 15B.

[0056] Figure 8A is a perspective view of electrosurgical pencil 400 having shaft 402 with movable tip assembly 404 in an extended position. Figure 8B is a perspective view of electrosurgical pencil 400 having shaft 402 with movable tip assembly 404 in a retracted position. Figures 8A and 8B will be discussed simultaneously.

[0057] The movable tip assembly 404 can include an outer dome electrode 406, an intermediate insulating layer 408, and an inner electrode 410. In the embodiment of Figures 8A-8B, the movable tip assembly 404 can include a movable tip assembly configured to extend (Figure 8B) from the shaft 402 (Figure 8A), allowing a pointed tip 436 (Figure 9) to be selectively exposed when the outer dome electrode 406 is pressed against tissue.

[0058] 8A and 8B showing a coupling mechanism 412 connecting the outer dome electrode 406 to the shaft 402. The middle insulating layer 408 can be axially aligned with the proximal body 440.

[0059] The movable tip assembly 404 may include concentric portions of an outer dome electrode 406, an intermediate insulating layer 408, and an inner electrode 410. In particular, the outer dome electrode 406 may all be movable and disposed distally of the tubular body 414. The cylindrical body 428 of the intermediate insulating layer 408 may be retained within the interior passageway 422 of the outer dome electrode 406 via, for example, an interference fit or adhesive. The elongated shaft 434 of the inner electrode 410 is configured to slide within the interior passageway 432 of the cylindrical body 428.

[0060] 8A, 8B, and 9 collectively, the shaft 302 may include a tubular body 414 to which an outer dome electrode 406 is attached. The tubular body 414 may be externally covered by a sheath 416 and may include a passageway 418 therein. The outer dome electrode 406 may include a tubular body 420 having an internal passageway 422 coaxially aligned with the passageway 418 of the shaft 402. The outer dome electrode 406 may include an exterior surface 424 and an end face 426. The internal passageway 422 of the outer dome electrode 406 may receive an intermediate insulating layer 408. The intermediate insulating layer 408 may include a distal portion having a cylindrical body 428 having an end face 430 and an internal passageway 432. The inner electrode 410 is disposed within the internal passageway 432 and may include an elongated shaft 434 and a pointed tip 436.

[0061] The intermediate insulating layer 408 may further include a proximal body 440 located proximal to the cylindrical body 428. The proximal body 440 may include an interior chamber 442 having a larger diameter than the interior passageway 432. The inner electrode 410 may further include a proximal portion 450 having a sheath 454.

[0062] The movable tip assembly 404 can be connected to the shaft 402 by a coupling mechanism 412 that includes a first spring 460A and a second spring 460B. The proximal body 440 can include a first pocket 462A and a second pocket 462B for receiving the first spring 460A and the second spring 460B, respectively. The first pocket 462A can include a first rear wall 464A, and the second pocket 462B can include a second rear wall 464B.

[0063] The first spring 460A and the second spring 460B can connect the movable tip assembly 404 to the shaft 402. The first spring 460A and the second spring 460B are shown exposed in FIG. 9 for illustrative purposes. However, the first spring 460A and the second spring 460B can be covered by flexible or corrugated tubing connected to the movable tip assembly 404 and the shaft 402. As an example, the first spring 460A and the second spring 460B can be electrically isolated from the flow of current or can form part of the path of current through the outer dome electrode 406. As an example, the outer dome electrode 406 can be connected to a wire that extends through a gap between the outer dome electrode 406 and the tubular body 414.

[0064] The first spring 460A and the second spring 460B may be attached to the proximal surface 470 or other portion of the tubular body 420 of the outer dome electrode 406 by any suitable means, such as welding or an interference fit. As an example, the distal ends of the first spring 460A and the second spring 460B may be disposed within sockets (not shown) located within the tubular body 420. The proximal ends of the first spring 460A and the second spring 460B may be attached to the distal surface 472 or other portion of the tubular body 414 by any suitable means, such as welding or an interference fit. As an example, the proximal ends of the first spring 460A and the second spring 460B may be disposed within a first pocket 462A and a second pocket 462B, respectively, within the tubular body 414. The first rear wall 464A and the second pocket 462B can provide surfaces against which the first spring 460A and the second spring 460B, respectively, can press. Thus, when the movable tip assembly 404 is pushed proximally, the first spring 460A and the second spring 460B can be pressed into the first pocket 462A and the second pocket 462B, respectively. Furthermore, the proximal surface 470 of the tubular body 420 can engage the distal surface 472 of the tubular body 414, thereby allowing the first spring 460A and the second spring 460B to be fully pressed into the first pocket 462A and the second pocket 462B, respectively. By way of example, the distance between the proximal surface 470 and the distal surface 472 can be approximately equal to the longitudinal length of the pointed tip 436. First spring 460A and second spring 460B illustrate various embodiments for movably connecting outer dome electrode 406 to shaft 402. However, other configurations may also be used, such as a single spring surrounding inner electrode 410, a leaf spring, a bellows spring, a wave washer / washer spring, etc.

[0065] Electrosurgical pencil 400 can be configured to operate similarly to electrosurgical pencil 200 of FIGS. 3A and 3B. For example, inner electrode 410 can be energized to deliver current to target tissue, outer dome electrode 406 can provide a current return path, and intermediate insulating layer 408 can electrically insulate inner electrode 410 from outer dome electrode 406. Furthermore, inner electrode 410 can be fixed by mechanical or metallurgical means similar to inner electrode 212. However, rather than being fixed like outer dome electrode 206, outer dome electrode 406 is configured to retract proximally with a portion of intermediate insulating layer 408. In particular, as described in more detail with reference to FIGS. 10A and 10B, first and second springs 460A and 460B can be disposed between outer dome electrode 406 and cylindrical body 428 of intermediate insulating layer 408 to allow pointed tip 436 to be exposed.

[0066] Figure 10A is a side view of the electrosurgical pencil 400 of Figures 8A and 8B with the outer dome electrode 406 in an extended position relative to tissue 480. Figure 10B is a side view of the electrosurgical pencil 400 of Figures 8A and 8B with the outer dome electrode 406 in a retracted position relative to tissue 480. Figures 10A and 10B are described simultaneously.

[0067] 7A and 7B, the sharp tip 436 can interact with the tissue 480 in a manner similar to the tissue 370. In particular, current can exit the distal-most end of the sharp tip 336 and enter a portion of the tissue 480. The current exiting the sharp tip 436 passes through only a small portion of the tissue 480, such as the area where electrotherapy is to be administered, before returning to the outer dome electrode 406, thereby eliminating or reducing the possibility of stray current flowing to undesired tissue areas.

[0068] 10A and 10B allows the outer dome electrode 406 to contact the tissue before the inner electrode 410, which advantageously ensures that the plasma forms on the inner electrode 410 and not the outer dome electrode 406. Thus, the outer dome electrode 406 contacts the tissue first and can be exposed when the inner electrode 410 is ready to be electrically activated as the electrosurgical pencil 400 is driven deeper into the tissue, e.g., pressed firmly against the tissue.

[0069] Figure 11A is a perspective side view of an electrosurgical pencil 500 in an extended state, including a shaft 502 and a tip assembly 504. Figure 11B is a perspective side view of the electrosurgical pencil 500 of Figure 11A in a retracted state. The tip assembly 504 can include an outer dome electrode 506, an intermediate insulating layer 508, and a reciprocating inner electrode 510. Figure 12A is a perspective cross-sectional view of the electrosurgical pencil 500 with the reciprocating inner electrode 510 in an extended state. Figure 12B is a perspective cross-sectional view of the electrosurgical pencil 500 of Figure 12A with the retracted state of the reciprocating inner electrode 510. Figures 11A through 12B are described simultaneously.

[0070] The shaft 502 can include a tubular body 514 to which an outer dome electrode 506 can be attached. The tubular body 514 can be surrounded by a sheath 516 on the outside and can include a passageway 518 on the inside. The outer dome electrode 506 can include a tubular body 520 having an internal passageway 522 coaxially aligned with the passageway 518 in the shaft 502. The outer dome electrode 506 can include an exterior surface 524 and an end face 526. The internal passageway 522 of the outer dome electrode 506 can receive an intermediate insulating layer 508. The intermediate insulating layer 508 can include a cylindrical body 528 having an end face 530 and an internal passageway 532. The reciprocating inner electrode 510 can be disposed within the internal passageway 532 and can include an elongated shaft 534 and a pointed tip 536.

[0071] The intermediate insulating layer 508 may further include a proximal portion 540 located proximal to the cylindrical body 528. The proximal portion 540 may include an interior chamber 542 having a larger diameter than the interior passageway 532. The reciprocating inner electrode 510 may further include a proximal portion 550. The proximal portion 550 may include a sheath 554.

[0072] The electrosurgical pencil 500 can be configured to operate similarly to the electrosurgical pencil 200 of Figures 3A and 3B. For example, a reciprocating inner electrode 510 can be energized to deliver current to the target tissue, an outer dome electrode 506 can provide a current return path, and an intermediate insulating layer 508 can electrically insulate the reciprocating inner electrode 510 from the outer dome electrode 506. However, rather than the reciprocating inner electrode 510 being fixed by mechanical or metallurgical means, the reciprocating inner electrode 510 can be configured to slide within the intermediate insulating layer 508. In particular, the reciprocating inner electrode 510 can be connected to a reciprocating device, such as a reciprocating mechanism 560 (Figure 13A), to provide a continuous back and forth motion to the reciprocating inner electrode 510, as indicated by arrow 558. This will be described in more detail with reference to Figures 13A and 13B.

[0073] Figure 13A is a side cross-sectional view of a reciprocating mechanism 560 for the electrosurgical pencil 500 of Figures 11A-12B with the drive shaft 562 in a retracted position. Figure 13B is a side cross-sectional view of the reciprocating mechanism 560 of Figure 13A with the drive shaft 562 in an extended position. Figures 13A and 13B will be described simultaneously.

[0074] The reciprocating mechanism 560 can include a cam 564 that can be connected to a rotary drive mechanism (not shown). As an example, the reciprocating mechanism 560 can be connected to the electric motor 118 in the handpiece 102 (FIG. 1). The cam 564 can include a socket 566 having a base 568 and a lobe 570. A proximal portion of the drive shaft 562 can be positioned within the socket 566. The drive shaft 562 can include a socket 572 having a lower base 574 and an upper base 576. A spring 578 can be disposed between the cam 564 and the drive shaft 562 and can urge the drive shaft 562 proximally, as indicated by arrow 580, to the left in FIG. 13A. Rotation of the cam 564 in the direction of arrow 582 can move the drive shaft 562 distally, as indicated by arrow 584, to the right in FIG. 13B, by, for example, the electric motor 118 (FIG. 1).

[0075] The position of the reciprocating inner electrode 510 can be controlled to a retracted state while the electrosurgical pencil 500 is navigated to the target tissue to prevent plasma formation on the outer dome electrode 506, similar to what was described with reference to Figures 9 through 10B. That is, a user of the electrosurgical pencil 100 (Figure 1) can press a button on the handpiece 102 to advance the reciprocating inner electrode 510 to a desired position before activating electrical energy.

[0076] Additionally, the reciprocating motion of the reciprocating inner electrode 510 can be used to remove debris from the reciprocating inner electrode 510. In particular, eschar, which is charred tissue, can adhere to the inner electrode of the electrosurgical pencils described herein. The reciprocating motion of the reciprocating inner electrode 510 can prevent eschar from adhering to the reciprocating inner electrode 510, and, if eschar does adhere, the reciprocating motion can scrape the eschar from the reciprocating inner electrode 510. Therefore, the gap between the outer diameter of the reciprocating inner electrode 510 and the inner diameter of the internal passage 532 can be small to facilitate such scraping. The accumulation of non-conductive eschar is undesirable because it can affect the surface area of ​​the reciprocating inner electrode 510 exposed to tissue, affecting plasma formation.

[0077] FIG. 14 is a side cross-sectional view of a reciprocating mechanism 600 suitable for the electrosurgical pencil 500 of FIGS. 11A-12B. The reciprocating mechanism 600 may be configured similarly to the reciprocating mechanism 560 of FIGS. 13A and 13B. Like the reciprocating mechanism 560, the reciprocating mechanism 600 may include a drive shaft 562 and a cam 564. As an example, the reciprocating mechanism 600 may additionally include a contact 602 to facilitate use with the hand piece 163 and socket 178 of FIG. 2A. In particular, the contact 602 allows a conductor 604 in the drive shaft 562 to reach a corresponding conductor in the hand piece 163 during reciprocation of a component connected to the contact 602. The conductor 604 may additionally be used in the reciprocating mechanism 560 of FIGS. 13A and 13B.

[0078] The drive shaft 562 connects to the electric motor 118 in the handpiece 163 and can rotate about axis AA (e.g., FIG. 3B). The cam 564 can reciprocate as indicated by arrow 606 with input from the drive shaft 562. The plug 608 can connect to the drive shaft 562 and surround the cam 564. The plug 608 can include the plug 172 of FIG. 2A. The conductor 604 is attached to the cam 564 and can reciprocate therewith. The conductor 604 can extend to the tip 176 (FIG. 2A) and energize the inner electrode, as described herein. The hub 610 of the contact 602 is fixed but can be configured to allow the conductor 604 to rotate therein. The contact 613 can be in electrical contact with the conductor 604, and the contact 615 can be in electrical contact with the socket 178. The contacts 613, 615 can be in electrical communication, such as via appropriate wiring.

[0079] As an example, reciprocating mechanism 560 and reciprocating mechanism 600 may be configured according to the reciprocating mechanism described in U.S. Pat. No. 11,712,291, entitled "Arthroscopic Instrument and Method," to Germain et al., the contents of which are incorporated herein by reference in their entirety.

[0080] Figure 15A is an end view of electrosurgical pencil 100 including outer dome electrode 206, intermediate insulating layer 210, and inner electrode 212 having a sharpened tip 236. Figure 15B is a side view of electrosurgical pencil 100 of Figure 15A showing that sharpened tip 236 extends beyond outer dome electrode 206.

[0081] The diameter of the inner electrode 212 can have a dimension 612. By way of example, dimension 612 can be approximately 0.013 inches (approximately 0.330 mm). By way of example, dimension 612 can range from approximately 0.010 inches (approximately 0.254 mm) to approximately 0.02 inches (approximately 0.508 mm).

[0082] The outer diameter of the inner electrode 212 can be spaced from the inner diameter of the end face 230 by a dimension 614. By way of example, the dimension 614 can be approximately 0.016 inches (approximately 0.4064 mm). By way of example, the dimension 614 can range from approximately 0.010 inches (approximately 0.254 mm) to approximately 0.02 inches (approximately 0.508 mm).

[0083] The outer diameter of end face 226 can be spaced apart from the outer diameter of end face 230 by dimension 616. By way of example, dimension 616 can be approximately 0.0076 inches (approximately 0.19304 mm). By way of example, dimension 616 can range from approximately 0.006 inches (approximately 0.1524 mm) to approximately 0.009 inches (approximately 0.2286 mm).

[0084] The pointed tip 236 can protrude beyond a dimension 618 of the end face 226. By way of example, the dimension 618 can be approximately 0.042 inches (approximately 1.0668 mm). By way of example, the dimension 618 can range from approximately 0.03 inches (approximately 0.762 mm) to approximately 0.06 inches (approximately 1.524 mm).

[0085] As an example, pointed tip 236 may have a surface area of ​​approximately 0.0008 square inches (approximately 0.516 square mm). As an example, outer dome electrode 206 may have an outer surface area of ​​approximately 0.0895 square inches (approximately 57.74 square mm). As an example, end face 226 may have a surface area of ​​approximately 0.0014 (approximately 0.903 square mm). Thus, the surface area ratio of outer dome electrode 206 to pointed tip 236 may be approximately 1.75:1, and the surface area ratio of end face 226 to pointed tip 236 may be approximately 111.88:1.

[0086] The systems, devices, and methods discussed in this application can help provide bipolar electrosurgical instruments and pencils capable of generating sufficient plasma for cutting, ablation, cauterization, and the like with low power consumption. The bipolar electrosurgical pencils described herein eliminate the need for a return electrode, including pads connected to the patient's body, thereby shortening the electrical return path through the patient. This can reduce or eliminate the risk of unintentional plasma delivery to tissue where treatment is not desired. The shapes of the inner and outer electrodes can be configured to provide a high surface area ratio between them. For example, the inner electrode can have a sharp tip, and the outer electrode can have a polyhedral dome shape. The sharp tip of the inner active electrode can concentrate electrical energy for plasma formation and reduce the surface area of ​​the inner electrode in contact with tissue. The dome shape of the outer inactive electrode can increase the surface area of ​​the outer inactive electrode in contact with tissue.

[0087] (Example) Example 1 is a bipolar electrosurgical surgical instrument that includes an elongated shaft extending along a central axis between a proximal end and a distal end, an outer electrode extending from the distal end, an inner electrode extending from within the elongated shaft to the outer electrode, and an intermediate insulating member disposed between the outer electrode and the inner electrode.

[0088] In Example 2, the subject matter of Example 1 can optionally include the elongate shaft having a first outer surface and the outer electrode having a second outer surface adjacent the first outer surface.

[0089] In Example 3, the subject matter of Example 2 can optionally include the first exterior surface of the elongate shaft being covered with an insulator.

[0090] In Example 4, the subject matter of any one or more of Examples 1 to 3 can optionally include the outer electrode, the inner electrode, and the intermediate insulating member being concentric.

[0091] In Example 5, the subject matter of any one or more of Examples 1 to 4 can optionally include the elongate shaft, the outer electrode, the inner electrode, and the intermediate insulating member being coaxial.

[0092] In Example 6, the subject matter of any one or more of Examples 2 through 5 can optionally include, wherein the outer electrode includes a dome that tapers downwardly from the elongate shaft toward a central axis of the elongate shaft.

[0093] In Example 7, the subject matter of Example 6 can optionally include, wherein the dome comprises a three-sided pyramid with rounded edges.

[0094] In Example 8, the subject matter of any one or more of Examples 1 through 7 can optionally include, wherein the inner electrode includes a pin having an elongated cylindrical body and a conical tip.

[0095] In Example 9, the subject matter of Example 8 can include the inner electrode being fixed relative to the middle insulating member in an extended position with the conical tip located distal to the middle insulating member.

[0096] In Example 10, the subject matter of any one or more of Examples 1 to 9 may optionally include the outer electrode being movable relative to the elongate shaft to allow a tip of the inner electrode to protrude from the intermediate insulating member.

[0097] In Example 11, the subject matter of Example 10 can optionally include a portion of the middle insulating member moving with the outer electrode.

[0098] In Example 12, the subject matter of any one or more of Examples 9 to 11 can optionally include the outer electrode being biased distally via one or more biasing elements to cover the conical tip.

[0099] In Example 13, the subject matter of any one or more of Examples 8 to 12 can optionally include the inner electrode being movable relative to the elongate shaft to move the conical tip in and out of the intermediate insulating member.

[0100] In Example 14, the subject matter of Example 13 can optionally include the inner electrode being biased outwardly of the middle insulating member.

[0101] In Example 15, the subject matter of any one or more of Examples 13 to 14 can optionally include a reciprocating device connected to the elongate shaft for reciprocating the inner electrode.

[0102] In Example 16, the subject matter of any one or more of Examples 7 to 15 can optionally include: the outer electrode including a first distal end surface; the intermediate insulating member including a second distal end surface; and the second distal end surface recessed into the outer electrode.

[0103] In Example 17, the subject matter of any one or more of Examples 1 through 16 can optionally include a sharpened tip where the inner electrode extends about 0.04 inches (about 0.10 cm) beyond the outer electrode.

[0104] In Example 18, the subject matter of Example 17 can optionally include, wherein the intermediate insulating member spaces the outer electrode about 0.016 inches (about 0.041 cm) from the inner electrode, and the inner electrode has a diameter of about 0.013 inches (about 0.033 cm).

[0105] In Example 19, the subject matter of any one or more of Examples 1 through 18 can optionally include the outer electrode extending from a distal-most end of the elongate shaft.

[0106] In Example 20, the subject matter of any one or more of Examples 1 through 19 can optionally include the inner electrode being surrounded by an insulating sleeve inside the elongate shaft.

[0107] Each of these non-limiting examples can stand on its own or can be combined with one or more of the other examples in various permutations or combinations.

[0108] (Various notes) The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples." Such examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. Furthermore, the inventors also contemplate examples using any combination or permutation of the elements shown or described (or one or more aspects thereof), with respect to the particular example (or one or more aspects thereof), or with respect to any other example (or one or more aspects thereof) shown or described herein.

[0109] In the event of a conflict in usage between this document and other documents incorporated by reference, the usage in this document takes precedence.

[0110] In this document, as is common in patent documents, the terms "a" or "an" are used to include one or more, regardless of other instances or uses of "at least one" or "one or more." In this document, the term "or" is used to refer to a non-exclusive "or," such that "A or B" means "A but not B," "B but not A," and "A and B." In this document, the terms "including" and "in which" are used as the plain-English equivalents of the terms "comprising" and "wherein," respectively. Also, in the following claims, the terms "including" and "comprising" are open-ended, i.e., systems, devices, articles, compositions, formulations, or processes that include elements in addition to the elements listed after such terms in a claim are considered to be within the scope of that claim. Furthermore, in the following claims, the terms "first," "second," "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

[0111] The example methods described herein may be implemented, at least in part, by a machine or computer. Some examples may include a computer-readable medium or machine-readable medium encoded with instructions that configure an electronic device to perform the methods described in the examples. An implementation of such methods may include code, such as microcode, assembly language code, high-level language code, or the like. Such code may include computer-readable instructions for performing various methods. The code may form part of a computer program product. Further, by way of example, the code may be tangibly stored, during execution or at other times, on one or more volatile, non-transitory, or non-volatile tangible computer-readable media. Examples of these tangible computer-readable media include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memory (RAM), read-only memory (ROM), and the like.

[0112] The above description is intended to be illustrative, not limiting. For example, the above examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments may be utilized by those of ordinary skill in the art upon reviewing the above description. This Summary is provided to comply with 37 C.F.R. §1.72(b) to enable the reader to quickly grasp the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Additionally, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be construed as intending that any unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Accordingly, the following claims are incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as an embodiment, and it is contemplated that such embodiments may be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. 1. A bipolar electrosurgical surgical instrument comprising: an elongate shaft extending along a central axis between a proximal end and a distal end; an outer electrode extending from the distal end; an inner electrode extending from inside the elongate shaft into the interior of the outer electrode; an intermediate insulating member disposed between the outer electrode and the inner electrode; 1. A bipolar electrosurgical surgical instrument comprising:

2. the elongate shaft has a first exterior surface; the outer electrode has a second outer surface contiguous with the first outer surface; 10. The electrosurgical bipolar surgical instrument of claim 1.

3. The electrosurgical bipolar surgical instrument according to claim 2 , wherein the first exterior surface of the elongate shaft is covered with an insulator.

4. The electrosurgical bipolar surgical instrument according to claim 1 , wherein the outer electrode, the inner electrode and the intermediate insulating member are concentric.

5. The electrosurgical bipolar surgical instrument according to claim 1 , wherein the elongate shaft, the outer electrode, the inner electrode and the intermediate insulating member are coaxial.

6. The electrosurgical bipolar surgical instrument according to claim 2 , wherein the outer electrode includes a dome that tapers downwardly from the elongate shaft toward a central axis of the elongate shaft.

7. The electrosurgical bipolar surgical instrument according to claim 6 , wherein the dome comprises a three-sided pyramid with rounded edges.

8. The electrosurgical bipolar surgical instrument according to claim 1 , wherein the inner electrode includes a pin having an elongated cylindrical body and a conical tip.

9. The electrosurgical bipolar surgical instrument according to claim 8, wherein the inner electrode is fixed relative to the intermediate insulating member in an extended position such that the conical tip is distal to the intermediate insulating member.

10. The electrosurgical bipolar surgical instrument according to claim 1 , wherein the outer electrode is movable relative to the elongate shaft to allow a tip of the inner electrode to protrude from the middle insulating member.

11. The electrosurgical bipolar surgical instrument according to claim 10 , wherein a portion of the middle insulating member moves with the outer electrode.

12. The electrosurgical bipolar surgical instrument according to claim 9, wherein the outer electrode is biased distally via one or more biasing elements to cover the cone-shaped tip.

13. The electrosurgical bipolar surgical instrument according to claim 8, wherein the inner electrode is movable relative to the elongate shaft to move the conical tip in and out of the middle insulating member.

14. The electrosurgical bipolar surgical instrument according to claim 13 , wherein the inner electrode is biased outwardly of the middle insulating member.

15. The electrosurgical bipolar surgical instrument according to claim 13, further comprising a reciprocator connected to the elongate shaft for reciprocating the inner electrode.

16. the outer electrode includes a first distal end surface; the intermediate insulating member includes a second distal end surface; The electrosurgical bipolar surgical instrument according to claim 7 , wherein the second distal end face is recessed inwardly of the outer electrode.

17. The electrosurgical bipolar surgical instrument according to claim 1, wherein the inner electrode includes a sharpened tip that extends about 0.04 inches (about 0.10 cm) beyond the outer electrode.

18. the intermediate insulating member spaces the outer electrode about 0.016 inches from the inner electrode; The electrosurgical bipolar surgical instrument according to claim 17, wherein the inner electrode has a diameter of about 0.013 inches (about 0.033 cm).

19. The electrosurgical bipolar surgical instrument according to claim 1 , wherein the outer electrode extends from a distal-most end of the elongate shaft.

20. The electrosurgical bipolar surgical instrument according to claim 1 , wherein the inner electrode is surrounded by an insulating sleeve inside the elongate shaft.

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