Patent Description:
Medical devices, such as endoscopes or other suitable insertion devices, are employed for a variety of types of diagnostic and surgical procedures, such as endoscopy, laparoscopy, arthroscopy, gynoscopy, thoracoscopy, cystoscopy, etc. Many of these procedures involve delivering energy to tissue of an organ or a gland to treat tumors, infections, and the like. Examples of such procedures include Endoscopic Mucosal Resection (EMR), Endoscopic Sub-mucosal Resection (ESR), Endoscopic Sub-mucosal Dissection (ESD), polypectomy, mucosectomy, etc. In particular, such procedures may be carried out by inserting an insertion device into a subject's body through a surgical incision, or via a natural anatomical orifice (e.g., mouth, vagina, or rectum), and performing the procedure or operation at a target site with an auxiliary device inserted through the insertion device.

<CIT> discloses an electrode device of an electrosurgical instrument, comprising at least one electrically conductive electrode section and an electrically insulating carrier section, wherein both the electrode section and the carrier section are made from a ceramic material. In order to improve the mechanical and electrical properties and in order to simplify the production, a green body of the carrier section and a green body of the electrode section are connected to each other, in particular materially, to form a single composite green body and are jointly sintered.

<CIT> discloses an electrosurgical instrument manufactured by presenting an electrode and attaching a sacrificial portion to the electrode to form a first electrode assembly. An insulating material is molded over the first electrode assembly to form a second electrode assembly, and the second electrode assembly is subjected to a further process which is capable of removing the sacrificial portion without removing the insulating material. The sacrificial portion is removed to form at least one cavity within the electrosurgical instrument.

<CIT> discloses a preparation instrument comprising an HF-instrument with an electrode that is partially insulated by means of an insulating body, which is combined with a fluid applicator having a channel arranged in the insulating body for the application of a fluid to or into tissue.

At times, during a medical procedure, a user may use an injection needle and an energy delivery device for purposes of raising, separating, flushing, cutting, dissecting, ablating, marking, coagulating, cauterizing, or otherwise treating and/or manipulating tissue. The injection and energy delivery may be performed separately. For example, in order to deliver energy to the tissue, the user may be required to remove the injection needle from the insertion device and deliver the energy delivery device through the insertion device to the tissue being targeted, and vice versa. During the procedure, the user may alternate using the injection needle and the energy delivery device, and exchanging devices may increase the duration and risks of the medical procedure. Additionally, one or more portions of the energy delivery device may inadvertently contact or harm tissue (or an inner channel of the insertion device) when energized. Furthermore, forming an energy delivery device with one or more insulated portions may be difficult, time-consuming, expensive, etc..

The devices and methods of this disclosure may rectify one or more of the deficiencies described above or address other aspects of the art.

The invention is defined in independent claim <NUM>, further embodiments are described in the dependent claims.

Examples of the disclosure relate to, among other things, medical devices configured for treating tissue by delivering electrical energy to the tissue, and methods for forming the medical devices. In some examples, the medical devices may also be configured to deliver fluid into and/or under the tissue. Each of the examples disclosed herein may include one or more of the features described in connection with any of the other disclosed examples.

In one example, a method of forming an energy delivery portion of a medical device may include contacting a distal portion of an electrode shaft with an insulating material, and heating the insulating material to couple the insulating material to the distal portion of the electrode shaft to form an insulation tip. The distal portion of the electrode shaft may include one or more surface contours to entrain the insulating material.

The method may include one or more of the following features. The method may further include shaping the insulating material in a mold such that the insulation tip insulates a distal end face of the electrode shaft. According to the invention the electrode shaft
includes an electrode shaft lumen. The method may further include an initial step of inserting a sacrificial element into a portion of the electrode shaft lumen. The method may further include removing the sacrificial element after the heating of the insulating material and shaping of the insulating material in the mold to form an insulation tip lumen that at least partially aligns with the electrode shaft lumen.

The heating of the insulating material may precede the contacting the distal portion of the electrode shaft with the insulating material. According to the invention the contacting the distal portion of the electrode shaft with the insulating material includes depositing the insulating material in a molten state, e.g. from a molten bath on the distal portion of the electrode shaft. The contacting the distal portion of the electrode shaft with the insulating material may include positioning a glass bead around the distal portion of the electrode shaft and positioning a non-conductive material around the glass bead. The method may further include fusing the non-conductive material to the electrode shaft by at least partially melting the glass bead.

The contacting the distal portion of the electrode shaft with the insulating material may include positioning the electrode shaft adjacent to a supply of insulating material, and rotating the electrode shaft. The heating the insulating material may include directing energy from a laser toward the electrode shaft or the insulating material.

The method may further include cooling the insulating material and the electrode shaft at a controlled rate for approximately one hour. The surface contours may include a plurality of circumferential projections or a roughened surface. The surface contours may be formed by machining. The electrode shaft may include stainless steel, and the insulating material may include a glass or a ceramic. The insulating material may include one or more filler materials. The one or more filler materials may have a thermal expansion coefficient between a thermal expansion coefficient of the glass or ceramic and a thermal expansion coefficient of a material forming the electrode shaft.

In another aspect, a method of forming an energy delivery portion of a medical device may include positioning a coupling element around a distal portion of an electrode shaft, positioning a bead of insulating material around the coupling element, and heating the coupling element to at least partially melt the coupling element to secure the bead of insulating material to the electrode shaft.

The method may include one or more of the following features. The method may further include compressing the bead of insulating material around the heated coupling element. The coupling element may be formed of glass and the bead of insulating material may be formed of ceramic. The method may further include an initial step of sintering or depositing metallic material on an inner portion of the ceramic bead of insulating material.

In yet another aspect, a method of forming an energy delivery portion of a medical device may include positioning a sacrificial element in an electrode shaft lumen of an electrode shaft, depositing an insulating material on a distal portion of the electrode shaft, and shaping the insulating material on the distal portion of the electrode shaft to form an insulation tip on the distal portion of the electrode shaft, and removing the sacrificial element from the electrode shaft lumen and the insulating material to form an insulation tip lumen that at least partially aligns with the electrode shaft lumen. The sacrificial element may extend distally beyond a distal end of the electrode shaft. The insulating material may be heated to an at least partially molten state.

The method may include one or more of the following aspects. The insulating material may be heated by directing a laser energy source toward the distal portion of the electrode shaft or toward a supply of the insulating material. The insulating material may be deposited on the distal portion of the electrode shaft by positioning the electrode shaft adjacent to the supply of insulating material, and rotating the electrode shaft.

It may be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure, as claimed.

Examples of the disclosure include devices and methods for one or more of: forming a portion of an electrode, facilitating and improving the efficacy, efficiency, and safety of treating and/or manipulating tissue when, for example, applying electrical energy to tissue with an electrode; delivering fluid into and/or under tissue during a medical procedure through the distal end of the electrode; and insulating a distal tip of the electrode. For example, aspects of the disclosure may provide a user (e.g., physician, medical technician, or other medical service provider) with an easy, efficient, inexpensive, etc., method of forming an electrode with one or more insulated portions, for example, an insulated distal tip. Aspects of the disclosure may provide the user with a strong and/or durable connection between the electrode and the insulation. Aspects of the disclosure may provide the user with the ability to apply electrical energy or heat to tissue using a medical device having an electrode, and to deliver fluid into and/or under tissue with the same medical device. Aspects of the disclosure may provide the user with the ability to apply electrical energy or heat and deliver fluid with a reduced likelihood of damaging tissue or contacting unintended portions of the tissue. Aspects of the disclosure may help the user penetrate a layer of tissue (e.g., a submucosal layer) to cause perforation. In these aspects, an insulated portion of the device may help maintain a separation or spacing between a cutting portion of the device and other tissue. Furthermore, aspects of the disclosure include steps to manufacture or otherwise form one or more electrodes and/or distal tips of a medical device. Some aspects of the disclosure may be used in performing an endoscopic, laparoscopic, arthroscopic, gynoscopic, thoracoscopic, cystoscopic, or other type of procedure.

Reference will now be made in detail to examples of the disclosure described above and illustrated in the accompanying drawings.

The terms "proximal" and "distal" are used herein to refer to the relative positions of the components of an exemplary medical device. When used herein, "proximal" refers to a position relatively closer to the exterior of the body of a subject or closer to a user, such as a medical professional, holding or otherwise using the medical device. In contrast, "distal" refers to a position relatively further away from the medical professional or other user holding or otherwise using the medical device, or closer to the interior of the subject's body. As used herein, the terms "comprises," "comprising," "having," "including," or other variations thereof, are intended to cover a non-exclusive inclusion, such that a device or method that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent thereto. Unless stated otherwise, the term "exemplary" is used in the sense of "example" rather than "ideal. " As used herein, the terms "about," "substantially," and "approximately," indicate a range of values within +/-<NUM>% of a stated value.

<FIG> depict a medical device <NUM> that includes a handle <NUM>, a shaft <NUM>, and a distal end <NUM>. Handle <NUM> may include a main body <NUM> and a movable body <NUM>. Handle <NUM> also may include a port <NUM> configured to receive fluid, and a hub <NUM> configured to receive electrical energy similar to an electrical plug or socket. Distal end <NUM> includes an end effector, for example, an energy delivery portion or an electrode portion <NUM> (hereinafter "electrode <NUM>"). Electrode <NUM> is electrically connected to hub <NUM>, and as discussed in detail below, may include a channel fluidly connected to, or otherwise in fluid communication with, port <NUM>. Additionally, as shown in <FIG> and discussed in detail below, electrode <NUM> may include an insulation tip <NUM>, which may at least partially surround a distal portion of an electrode shaft <NUM>.

Medical device <NUM> may be inserted into a body lumen of a subject, either through an insertion device (not shown) or alone, such that at least a portion of shaft <NUM> may be within the subject, while handle <NUM> may remain outside of the subject. Distal end <NUM> may be positioned at a target site within the subject. From outside of the subject, a user can manipulate handle <NUM>. Movement of movable body <NUM> relative to main body <NUM> in a first direction (e.g., the distal direction) may extend electrode <NUM> relative to shaft <NUM> (e.g., move electrode <NUM> distally relative to a distal end of shaft <NUM>). Movement of movable body <NUM> relative to main body <NUM> in a second direction (e.g., the proximal direction) may retract electrode <NUM> relative to shaft <NUM> (e.g., move electrode <NUM> proximally relative to a distal end of shaft <NUM>). Although not shown, movable body <NUM> or additional components of handle <NUM> may articulate electrode <NUM> (or electrode <NUM> and distal end <NUM>) left or right, and/or up or down relative to shaft <NUM>.

Handle <NUM> may be coupled to a fluid source (not shown) via port <NUM>. Port <NUM> may be in fluid communication with electrode <NUM> via an internal lumen <NUM>, which may extend through handle <NUM> (<FIG>) and shaft <NUM>. It is noted that various portions of handle <NUM> shown in <FIG> may not be to scale, in order to more fully illustrate various portions of handle <NUM>. In one aspect, internal lumen <NUM> may extend longitudinally through main body <NUM> of handle <NUM> and shaft <NUM> to fluidly connect port <NUM> to electrode <NUM>. Port <NUM> may be positioned on a proximal portion of main body <NUM>, for example, a proximal end of main body <NUM>. Alternatively, port <NUM> may be positioned on a distal or central portion of main body <NUM>. Moreover, port <NUM> may include a one-way valve, a luer, a seal, threading, and/or any appropriate element to help maintain a secure connection between handle <NUM> and the fluid source, minimize or prevent back-flow (e.g., fluid flowing proximally out of port <NUM>), and/or minimize or prevent leakage. In one example, a one-way valve may include an outer housing containing an inner elastomeric and/or gelatinous sealing member (not shown).

Handle <NUM> may be coupled to an energy source (not shown) via hub <NUM>. Hub <NUM> may include one or more prongs or pins <NUM> to couple to the energy source. Hub <NUM> may be electrically coupled to electrode <NUM> via a conductive element <NUM>, which may be electrically coupled to pin <NUM> and extend through handle <NUM> and through at least a portion of shaft <NUM>. The energy source may be an electrocautery source, a radio frequency generator, a heating source, a current generator, etc. In one aspect, medical device <NUM> may be used for monopolar electrosurgery, and may include a return electrode positioned remotely from electrode <NUM> on or otherwise adjacent to the subject. In another aspect, medical device <NUM> may be used for bipolar electrosurgery. In that instance, electrode <NUM> may include an active electrode portion, and a return electrode may be provided at or near another portion of electrode <NUM> and/or shaft <NUM>. In one example, although not shown, two conductive elements may run through shaft <NUM>, where the conductive elements may be electrically isolated from each other, allowing one to conduct energy to the active electrode and the other to conduct energy from a return electrode.

Hub <NUM> may be positioned on main body <NUM>, for example, on a proximal end of main body <NUM>. In one aspect, port <NUM> may extend from the proximal end of main body <NUM> in a direction parallel to or coaxial with a longitudinal axis of main body <NUM>, and hub <NUM> may extend from the proximal end of main body <NUM> at an angle transverse (e.g., approximately <NUM> degrees) to the longitudinal axis of main body <NUM>. In another aspect, hub <NUM> may be positioned on a distal or central portion of main body <NUM>, or on movable body <NUM>. Although not shown, main body <NUM> and/or hub <NUM> may include a one-way valve, a luer, a seal, threading, and/or any appropriate element to help maintain a secure connection between handle <NUM> and the energy source, minimize or prevent back-flow (e.g., fluid flowing from port <NUM> and/or internal lumen <NUM> and proximally out of hub <NUM>), and/or minimize or prevent leakage.

In one aspect shown in <FIG>, pin <NUM> may extend through hub <NUM> transverse to a longitudinal axis of handle <NUM>, and may be electrically and physically connected to conductive element <NUM>, such as a wire, a cable, and/or a braided sheath. Conductive element <NUM> may be electrically conductive or include an electrically conductive element, and conductive element <NUM> may extend longitudinally through internal lumen <NUM> and through shaft <NUM>. As shown in <FIG>, fluid delivered through port <NUM> may surround at least a portion of conductive element <NUM>. In one aspect, conductive element <NUM> may include one or more layers of insulation to help insulate conductive element <NUM> from the fluid in internal lumen <NUM>. As alluded to above, a second conductive element (not shown) may be provided as a return pathway where medical device <NUM> has a bipolar configuration. Although not shown, in another aspect, the energy source may be a part of handle <NUM> (e.g., an internal battery in handle <NUM>).

As mentioned, handle <NUM> may control the extension or retraction of electrode <NUM> relative to the distal end <NUM> of shaft <NUM>. For example, main body <NUM> may include a slot <NUM>, and movable body <NUM> may be slidably positioned within slot <NUM>. For example, main body <NUM> may be configured to be held by a user's hand, and movable body <NUM> may be configured to be controlled by the movement of the user's thumb. For example, a side of main body <NUM> opposite to movable body <NUM> may include one or more contours <NUM>, which may help the user grip main body <NUM>. Movable body <NUM> may be lockable in one or more positions relative to main body <NUM>, and/or may be spring-biased in a direction (e.g., toward a proximally retracted position).

Movable body <NUM> may be coupled to a drive element, and the drive element may impart distal or proximal movement to at least a portion of electrode <NUM> based on relative movement between main body <NUM> and movable body <NUM>. In one aspect, conductive element <NUM> may also act as a drive wire, rod, cable, or the like, such that conductive element <NUM> may impart distal or proximal movement to at least a portion of electrode <NUM> while also coupling electrode <NUM> to hub <NUM>, e.g., to the one or more pins <NUM>, to deliver the energy to (and/or from) electrode <NUM>. As shown in <FIG>, movable body <NUM> may be coupled to conductive element <NUM> via a coupling mechanism, for example, a coupler <NUM>. In one aspect, coupler <NUM> may be physically coupled (either directly or indirectly) to movable body <NUM>, and may also be physically coupled (either directly or indirectly) to conductive element <NUM> such that movement of movable body <NUM> extends or retracts conductive element <NUM>, and thus extends or retracts electrode <NUM>. It is noted that coupler <NUM> and/or other components within handle <NUM> may help maintain the electrical connection between pin <NUM> and conductive element <NUM> when conductive element <NUM>, and thus electrode <NUM>, is in the retracted or extended position. Alternatively, in another aspect, coupler <NUM> and/or other components within handle <NUM> may be configured to only electrically connect pin <NUM> and conductive element <NUM> when conductive element <NUM>, and thus electrode <NUM>, is in the extended position, or an at least partially extended position.

As shown in <FIG>, handle <NUM> may also include one or more indicators, for example, indicators 39A, 39B. For example, indicators 39A, 39B may visually indicate to the user the position of electrode <NUM> relative to shaft <NUM>. The position of indicators 39A, 39B may also correspond with the position of movable body <NUM>. For example, indicator 39A may be positioned on handle <NUM> at a position corresponding with a retracted position of movable body <NUM>, and may indicate that electrode <NUM> is retracted relative to shaft <NUM>. Similarly, indicator 39B may be positioned on handle <NUM> at a position corresponding with an extended position of movable body <NUM>, and may indicate that electrode <NUM> is extended relative to shaft <NUM>.

As shown in <FIG>, shaft <NUM> extends from a distal portion of main body <NUM> to distal end <NUM>, and may surround at least a portion of electrode <NUM>. Shaft <NUM> may be a sheath that surrounds at least a portion of one or more lumens (e.g., lumen <NUM>) and the drive wire (e.g., conductive element <NUM>). In another aspect, shaft <NUM> may be an extrusion that includes one or more lumens extending from handle <NUM> to distal end <NUM>.

The enlarged portion of <FIG> illustrates additional features of shaft <NUM> and distal end <NUM>. Electrode <NUM> includes insulation tip <NUM> surrounding a distal portion of electrode shaft <NUM>. Electrode <NUM> may be positioned within a portion of an end cap <NUM> of distal end <NUM>. End cap <NUM> may include a distal end face <NUM>. End cap <NUM> may be at least partially electrically insulating. For example, end cap <NUM> may be formed of a ceramic material or another non-conductive material. Alternatively, only distal end face <NUM> and an internal portion of end cap <NUM> that contacts and/or surrounds electrode <NUM> may be electrically insulating. Distal end face <NUM> includes a central opening <NUM> through which electrode <NUM> may extend and retract. End cap <NUM> includes a central portion <NUM> through which electrode shaft <NUM> may move during the extension and retraction. Additionally, although not shown, end cap <NUM> may be fixedly coupled to shaft <NUM> via welding, an adhesive, crimping, friction fit, or other appropriate coupling.

Electrode <NUM> may be coupled to a proximal support <NUM> of distal end <NUM>, which may include a cylindrical extension <NUM>. Proximal support <NUM> may be coupled to a portion of the drive wire (e.g., conductive element <NUM>) via a drive wire receiving portion <NUM>, for example, via welding, an adhesive, crimping, friction fit, or any other permanent or temporary coupling. Cylindrical extension <NUM> may extend distally and may receive at least a portion of electrode <NUM>. Electrode <NUM> and cylindrical extension <NUM> may be coupled via welding, an adhesive, crimping, friction fit, or other appropriate coupling. In one aspect, cylindrical extension <NUM> may allow for different electrodes <NUM> to be removably coupled to distal end <NUM>. Proximal support <NUM> includes a support lumen <NUM>, and support lumen <NUM> fluidly connects port <NUM> to electrode <NUM>, for example, via a lumen (e.g., lumen <NUM>) through shaft <NUM>.

Electrode <NUM> and proximal support <NUM> may be movable relative to end cap <NUM> in response to the relative movement of movable body <NUM> and main body <NUM> of handle <NUM>. For example, with movable body <NUM> in a proximal position relative to main body <NUM>, electrode shaft <NUM> may be substantially retracted within end cap <NUM> with only a distal portion of electrode <NUM> (e.g., insulation tip <NUM>) extending distally beyond end cap <NUM>. Then, as movable body <NUM> is translated distally relative to main body <NUM>, electrode <NUM> and proximal support <NUM> translate distally relative to end cap <NUM> such that a greater portion of electrode <NUM> (e.g., electrode shaft <NUM>) extends distally beyond end cap <NUM> through central opening <NUM>.

Alternatively, although not shown, central opening <NUM> may be larger than insulation tip <NUM>, and with movable body <NUM> in the proximalmost position, electrode <NUM> (including insulation tip <NUM>) may be fully retracted within central opening <NUM> of end cap <NUM>. Furthermore, in one aspect, movable member <NUM> may have an equilibrium position relative to main body <NUM>, and the equilibrium position may correspond to electrode shaft <NUM> being partially extended from end cap <NUM>.

As shown in the enlarged portion of <FIG>, electrode shaft <NUM> includes a distal tip <NUM> and a longitudinal portion <NUM>. Electrode shaft <NUM> may include one or more graduated portions, for example, with varying diameters, which may aid in the coupling of electrode shaft <NUM> to proximal support <NUM>, may help to form one or stop surfaces (e.g., abutting an internal portion of end cap <NUM>, etc. Electrode shaft <NUM> also may include an electrode shaft lumen <NUM> extending through electrode shaft <NUM>, for example, extending longitudinally through a central portion of electrode shaft <NUM>. Electrode shaft lumen <NUM> may be in fluid communication with port <NUM> via support lumen <NUM> through proximal support <NUM>. In one aspect, inner sheath <NUM> may form at least a portion of the fluid connection between lumen <NUM> and port <NUM>. Additionally, electrode shaft lumen <NUM> may be in fluid communication with an insulation tip lumen 28C to form a channel to deliver fluid from a distal end of electrode <NUM>. Nevertheless, it is noted that, in some aspects, medical device <NUM> may be used only to deliver energy, and not to deliver fluid. In this aspect, electrode shaft <NUM> may not include electrode shaft lumen <NUM>, and/or insulation tip <NUM> may not include insulation tip lumen 28C.

As shown in <FIG>, insulation tip <NUM> may include a distal end 28A and a side portion 28B. Distal end 28A may be rounded, for example, substantially hemispherical, and side portion 28B may include straight sides, for example, may be substantially cylindrical. In one aspect, the shapes of distal end 28A and side portion 28B may help distal end <NUM> be atraumatic, and/or may help abut, position, manipulate, or otherwise treat tissue, while electrode <NUM> may be used to cut, dissect, ablate, mark, coagulate, cauterize, or otherwise treat tissue. Nevertheless, this disclosure is not so limited, and insulation tip <NUM>, including distal end 28A and side portion 28B, may include other shapes. For example, insulation tip <NUM> may be frustoconical, tapered, chamfered, filleted, beveled, or combinations thereof. In one aspect, insulation tip <NUM> completely surrounds or covers a distal portion (e.g., distal tip <NUM>) of electrode shaft <NUM>. In this aspect, insulation tip <NUM> may provide an insulation from the distal portion of electrode shaft <NUM> and at least a portion of the tissue near insulation tip <NUM>. For example, insulation tip <NUM> may abut tissue, and electrode shaft <NUM> may be energized while insulation tip <NUM> helps to insulate the tissue that insulation tip <NUM> abuts against. Moreover, insulation tip <NUM> may receive distal tip <NUM> within approximately one half of insulation tip <NUM> along the longitudinal axis, which may help securely couple insulation tip <NUM> and electrode <NUM>. Additionally, approximately one half of insulation tip <NUM> may extend distally beyond distal tip <NUM>, which may help insulate tissue abutting distal portion 28A of insulation tip <NUM> when electrode <NUM> is energized. In some aspects, insulation tip <NUM> may include a thickness of approximately <NUM> to <NUM>. Furthermore, a thickness of insulation tip <NUM> may depend on a dielectric strength and/or other characteristics of the insulating material(s) forming insulation tip <NUM>, the amount of energy to be delivered via electrode shaft <NUM>, a surface roughness of electrode shaft <NUM>, and/or one or more other characteristics of the system or treatment procedure.

As discussed below, insulation tip <NUM> and electrode shaft <NUM> may be physically coupled, for example, via one or more fusing or coupling mechanisms or techniques. Moreover, in some aspects, insulation tip <NUM> and electrode shaft <NUM> form a fluid channel that extends through both electrode shaft <NUM> and insulation tip <NUM> in order to deliver (e.g., inject) fluid to a target site (e.g., within or between layers of tissue to raise, separate, flush, or otherwise treat tissue). Electrode shaft <NUM> may be energized, and the exposed portion of electrode shaft <NUM> (e.g., longitudinal portion <NUM>) may be used to cut, dissect, ablate, mark, coagulate, cauterize, or otherwise treat tissue. Insulation tip <NUM> may insulate a portion of electrode shaft <NUM> (e.g., distal tip <NUM>), and may help provide a separation between the active portion of electrode shaft <NUM> and tissue.

<FIG> illustrate additional aspects of electrode <NUM> that may form a portion of distal end <NUM> of medical device <NUM>. <FIG> shows a side view of electrode <NUM>, and <FIG> shows a cross-sectional view of electrode <NUM>. As mentioned, electrode <NUM> includes insulation tip <NUM> surrounding electrode shaft <NUM>. Insulation tip <NUM> may include distal portion 28A and side portion 28B. As shown in <FIG> and <FIG>, insulation tip <NUM> may include insulation tip lumen 28C. In this aspect, fluid delivered through electrode shaft lumen <NUM> may be delivered distally through insulation tip lumen 28C. In one aspect, electrode shaft lumen <NUM> and insulation tip lumen 28C may be approximately the same size. In another aspect, electrode shaft lumen <NUM> and insulation tip lumen 28C may be tapered distally such that distal portions of the lumens are narrower than proximal portions of the lumens. Alternatively, electrode shaft lumen <NUM> and insulation tip lumen 28C may be tapered proximally such that proximal portions of the lumens are narrower than distal portions of the lumens. In these aspects, varying sizes of electrode shaft lumen <NUM> and insulation tip lumen 28C may help increase or decrease the pressure of the fluid being delivered through the fluid channel. A distal end portion 28D of insulation tip lumen 28C may include a chamfer or angled portion, which may help disperse, direct, or otherwise control delivery of fluid to a target site. In some aspects, a chamfer or angled portion may decrease the likelihood of damaging tissue. Nevertheless, as mentioned above, in some aspects, medical device <NUM> may not deliver fluid, and electrode <NUM> may not include electrode shaft lumen <NUM> and/or insulation tip <NUM> may not include insulation tip lumen 28C.

Additionally, distal end 28A of insulation tip <NUM> may include an internal face 28E. When insulation tip <NUM> and electrode shaft <NUM> are coupled together, a distal end face <NUM> of electrode <NUM> may abut internal face 28E. In this aspect, insulation tip <NUM> may insulate distal end face <NUM> of electrode shaft <NUM>.

Insulation tip <NUM> may be formed of one or more of a ceramic (e.g., zirconia, an alloy containing zirconium (e.g., ZrO<NUM>), aluminum oxide (Al<NUM>O<NUM>), a ceramic alloy, etc.), a glass (e.g., silicon dioxide (i.e., SiO<NUM>), a borosilicate glass, a silicate, etc.), a polymer material (e.g., a fluoropolymer, polyether ether ketone (PEEK), etc.), or another medically-safe, heat-resistant, and non-conductive material. Electrode shaft <NUM> may be formed of a conductive material, for example, a stainless steel (e.g., <NUM> stainless steel), titanium, or another medically-safe and conductive material. In one aspect, electrode shaft <NUM> may include a surface finish, for example, may be passivated per ASTM A967 Nitric <NUM>.

Various portions of insulation tip <NUM> may include heights and widths, for example, as measured relative to a longitudinal axis of insulation tip <NUM>. Insulation tip <NUM> may include a width (e.g., at a proximal end of side portion 28B) of approximately <NUM> to <NUM>, for example, approximately <NUM>. Insulation tip <NUM> may have a height (e.g., from the proximal end of side portion 28B to a distal end face of distal end 28A) of approximately <NUM> to <NUM>, for example, approximately <NUM>. For example, distal end 28A of insulation tip <NUM> may be rounded (e.g., substantially hemispherical), and may include a radius of approximately <NUM> to <NUM>, for example, approximately <NUM>. Although not shown, insulation tip <NUM> may include a cylindrical tip portion or another shape. Side portion 28B may have a height of approximately <NUM> to <NUM>, for example, approximately <NUM>. Moreover, in some aspects, the heights and widths of insulation tip <NUM> may vary depending on the material, size, type, intended treatment, etc. of electrode <NUM> and/or the material from which insulation tip <NUM> is formed. For example, if electrode <NUM> is delivering a higher energy level, insulation tip <NUM> may be thicker (e.g., have a larger width or height). Alternatively, if electrode <NUM> is delivering a lower energy lever, insulation tip <NUM> may be thinner (e.g., have a smaller width or height).

Additionally, as shown in <FIG>, the wider portion of insulation tip lumen 28C formed by radial internal portion 28F (e.g., where insulation tip <NUM> overlaps with electrode shaft <NUM>) may include a height of approximately <NUM> to <NUM>, for example, approximately <NUM>, and the narrower portion of insulation tip lumen 28C (e.g., wherein insulation tip <NUM> does not overlap with electrode shaft <NUM>) may include a height of approximately <NUM> to <NUM>, for example, approximately <NUM>. The wider portion of insulation tip lumen 28C formed by radial internal portion 28F (e.g., where insulation tip <NUM> overlaps with electrode shaft <NUM>) may include a width of approximately <NUM> to <NUM>, for example, approximately <NUM>, and the narrower portion of insulation tip lumen 28C (e.g., wherein insulation tip <NUM> does not overlap with electrode shaft <NUM>) may include a width of approximately <NUM> to <NUM>, for example, approximately <NUM>. As mentioned, distal end portion 28D may include a chamfer or angled portion, which may transition from the width of the narrowed lumen, for example, approximately <NUM>, to a wider width, for example, approximately <NUM>. In this aspect, the chamfer or angled portion of distal portion 28D may include an angle of approximately <NUM> degrees relative to the longitudinal axis.

Various portions of electrode shaft <NUM> may include heights and widths, for example, as measured relative to a longitudinal axis of electrode shaft <NUM>. Electrode shaft <NUM> may include a total height of approximately <NUM> to <NUM>, for example, approximately <NUM>. In one aspect, electrode shaft lumen <NUM> and insulation tip lumen 28C may be approximately the same width (e.g., in a direction transverse to the longitudinal axis of electrode shaft lumen <NUM> and insulation tip lumen 28C). For example, electrode shaft lumen <NUM> and insulation tip lumen 28C may include constant widths of approximately <NUM>.

<FIG> illustrate steps of an exemplary method that may be performed to form an electrode <NUM> similar to electrode <NUM>, with similar elements shown by <NUM> added to the reference numbers. For example, electrode <NUM> includes an insulation tip <NUM> on an electrode shaft <NUM>. As shown in <FIG>, insulation tip <NUM> is formed by depositing molten insulating material, for example, from a molten bath on a distal portion of electrode shaft <NUM>. The steps shown in <FIG> may include controlled cooling, molding, or other shaping techniques.

<FIG> illustrate a distal portion of electrode <NUM>. As shown, a distal portion of electrode shaft <NUM>, for example, distal tip <NUM>, includes one or more entrainment features or surface contours <NUM>. For example, <FIG> illustrate cross-sectional views of electrode <NUM>, and surface contours <NUM> may be radial projections that extend away from distal tip <NUM> of electrode shaft <NUM>, for example, in a direction radially outward from the longitudinal axis of electrode <NUM>. Surface contours <NUM> may circumferentially surround portions of distal tip <NUM>. Alternatively, surface contours <NUM> may be formed by radial projections that extend from, but do not circumferentially surround, portions of distal tip <NUM>. Surface contours may be formed during the molding of electrode shaft <NUM>. Alternatively, surface contours <NUM> may be formed by machining one or more portions of distal tip <NUM> or by affixing one or more surface contours <NUM> to distal tip <NUM>, e.g., via welding. In another aspect, surface contours <NUM> may be formed by a ribbed or roughened surface on one or more portions of distal tip <NUM>. In this aspect, a first step of forming electrode <NUM> includes forming electrode shaft <NUM> with one or more surface contours <NUM> on distal tip <NUM>.

As shown in <FIG>, a second step of forming electrode <NUM> includes depositing an insulating material <NUM> on the distal portion of electrode shaft <NUM>, for example, in a molten state. In one aspect, a drop, blob, or other amount of molten insulating material <NUM> may be applied to a distal portion of electrode shaft <NUM>. In another aspect, the distal portion of electrode shaft <NUM> may be inserted into a bath of molten insulating material <NUM>. In these aspects, surface contours <NUM> may help to capture, bind to, or otherwise entrain or retain insulating material <NUM> around electrode shaft <NUM>. insulating material <NUM> may surround the entirety of distal tip <NUM>, or, as shown in <FIG>, insulating material <NUM> may only surround a portion of distal tip <NUM>. For example, if surface contours <NUM> are formed by one or more projections, one or more of the projections may not be covered by insulating material <NUM>. In this aspect, the uncovered surface contours <NUM> may provide one or more conductive projections that may be used to treat tissue.

As shown in <FIG>, a third step of forming electrode <NUM> includes shaping insulating material <NUM>. For example, shaping insulating material <NUM> may include a mold <NUM> or other shaping mechanism. As shown in <FIG>, mold <NUM> may include two or more separate components, a first mold portion 166A and a second mold portion 166B, for example, to form a clamshell mold. In this aspect, first mold portion 166A and second mold portion 166B may be positioned around insulating material <NUM> and electrode shaft <NUM>, and bringing first mold portion 166A and second mold portion 166B into abutting contact (or close to abutting contact) may squeeze or otherwise shape insulating material <NUM>.

It is noted that the third step of forming electrode <NUM>, shown in <FIG>, may be performed while insulating material <NUM> is still at least partially molten, for example, while insulating material <NUM> is malleable and has not yet fully cooled. Insulating material <NUM> may then cool or at least partially cool, for example, to room temperature, while surrounded by mold <NUM>. Although not shown, electrode <NUM>, with insulating material <NUM> in mold <NUM>, may be positioned in a controlled temperature environment, for example, in order to control the cooling rate. In this aspect, a gradual cooling (e.g., over the course of approximately <NUM> hour) may help to couple insulating material <NUM> to electrode shaft <NUM>, for example, by preventing or reducing thermal stresses caused by different cooling rates or other thermal properties of the materials, which may help to prevent breakage (e.g., cracks, uncoupling, etc.) of assembled electrode <NUM>. Additionally, gradual cooling may help to prevent breakage of electrode <NUM> during usage, for example, as portions of electrode <NUM> heat up during energy delivery.

As mentioned, electrode shaft <NUM> may be formed of stainless steel. Insulating material <NUM> may be formed of, for example, ceramic (e.g., zirconia, an alloy containing zirconium (e.g., ZrO<NUM>), aluminum oxide (Al<NUM>O<NUM>), a ceramic alloy, etc.) or other suitable materials. Alternatively or additionally, insulating material <NUM> may be formed of a polymer material (e.g., a fluoropolymer, polyether ether ketone (PEEK), etc.) or another biocompatible, heat-resistant, and non-conductive material, such as, for example, a glass (silicone-based, boron-based, etc.). These materials have different thermal properties, so gradual cooling may help to minimize affects these different thermal properties may have on performance, for example, the strength and/or durability of the coupling insulating material <NUM> to electrode shaft <NUM>.

Lastly, once insulating material <NUM> has sufficiently cooled, mold <NUM> may be removed, forming electrode <NUM>. For example, as shown in <FIG>, electrode <NUM> includes insulation tip <NUM> formed of insulating material <NUM> on a distal portion of electrode shaft <NUM>. Moreover, different molds <NUM> may be used to shape insulating material <NUM> in different shapes, for example, in order to form different electrodes <NUM>. As shown in <FIG>, insulation tip <NUM> may include a rounded distal end 128A and cylindrical side portion 128B. Additionally, insulation tip <NUM> may not include an insulation tip lumen. In this aspect, as shown in <FIG>, insulating material <NUM> may surround and/or fill a distal portion of an electrode shaft lumen <NUM>.

<FIG> illustrate steps of an exemplary method that may be performed to form an electrode <NUM> similar to electrode <NUM>, with similar elements shown by <NUM> added to the reference numbers. For example, electrode <NUM> includes an insulation tip <NUM> on an electrode shaft <NUM>, with insulation tip <NUM> including a rounded distal end 228A and a cylindrical side portion 228B. Similar to <FIG>, insulation tip <NUM> may be formed by depositing insulating material from a molten bath, for example, with controlled cooling, molding, or other shaping techniques. As shown in <FIG>, insulation tip <NUM> may include an insulation tip lumen 228C, for example, fluidly connected to an electrode shaft lumen <NUM>. Insulation tip lumen 228C may connect to a distal end of insulation tip <NUM> via a divot or inset portion of insulation tip <NUM>, for example, at least partially formed by a sacrificial element <NUM>, as discussed below. In one example, additional processing steps may be performed on insulation tip <NUM> (e.g., selective heating) to help shape insulation tip <NUM>.

As shown in <FIG>, electrode shaft <NUM> includes electrode shaft lumen <NUM>. Additionally, electrode shaft <NUM> may include one or more surface contours <NUM>, for example, on a distal tip <NUM>. Moreover, one or more frangible or sacrificial elements <NUM> may be positioned in a portion of electrode shaft lumen <NUM>. Sacrificial element <NUM> may be a substantially rod-shaped plug. Sacrificial element <NUM> may extend proximally into a portion of electrode shaft lumen <NUM>, and may extend distally of electrode shaft <NUM>. Sacrificial element <NUM> may include a diameter approximately equal to an inner diameter of electrode shaft lumen <NUM>. In one aspect, if insulating material <NUM> is deposited to extend approximately <NUM> beyond a distal end of electrode shaft <NUM>, sacrificial element <NUM> may be approximately <NUM> long in order to extend into electrode shaft lumen <NUM> and also extend distally beyond electrode shaft <NUM>. Sacrificial element <NUM> may be formed of one or more of graphite, boron nitride, or another appropriate (e.g., frangible) material to be removably received within electrode shaft lumen <NUM> and to at least partially prevent ingress of insulating material <NUM> into electrode shaft lumen <NUM> during formation of insulating material <NUM> on electrode <NUM>.

As shown in <FIG>, insulating material <NUM> may be deposited on electrode shaft <NUM>, as discussed above with respect to <FIG>. Surface contours <NUM> may help to couple insulating material <NUM> to electrode shaft <NUM>. In this aspect, internal portions of insulation tip <NUM> may be entrained by surface contours <NUM> and/or may form shapes that correspond to the shape of surface contours <NUM> (i.e., mirror or form inverse shapes). Sacrificial element <NUM> may help to prevent insulating material <NUM> from surrounding, filling, or otherwise obstructing electrode shaft lumen <NUM>. As discussed above, although not shown, insulating material <NUM> may be shaped, molded, etc., for example, via a clamshell mold, in order to form insulation tip <NUM>. For example, the mold may include an opening to receive a portion of sacrificial element <NUM>. Additionally, insulating material <NUM> and electrode shaft <NUM> may be gradually cooled.

As shown in <FIG>, sacrificial element <NUM> may be removed. In one aspect, sacrificial element <NUM> may be removed from electrode shaft lumen <NUM> and insulating material <NUM> when insulating material <NUM> has partially (but not fully) cooled. With sacrificial element <NUM> removed, electrode shaft lumen <NUM> may be fluidly connected to insulation tip lumen 228C. insulation tip lumen 228C may at least partially align with electrode shaft lumen <NUM>. Accordingly, fluid may be delivered through electrode shaft <NUM> and insulation tip <NUM> to treat tissue, as discussed above.

Although not shown, additional processing steps may be performed, for example, to smooth out portions of insulation tip <NUM>. For example, the removal of sacrificial element <NUM> may cause one or more portions of distal end 228A to include sharp edges, cracks, etc. In this aspect, one or more portions of distal end 228A may be heated (e.g., to partially melt insulating material <NUM>) or otherwise treated to smooth out sharp edges, fill in cracks, or otherwise address inconsistent features of insulation tip <NUM>.

<FIG> illustrates steps of an exemplary method that may be performed to form an electrode <NUM> similar to electrode <NUM>, with similar elements shown by <NUM> added to the reference numbers. For example, electrode <NUM> includes an insulation tip <NUM> on an electrode shaft <NUM>. Insulation tip <NUM> may be a preformed element formed of an insulating material, for example, a glass (e.g., a silicate, a borosilicate, or any biocompatible glass) discussed herein, and electrode shaft <NUM> may be metallic (e.g., stainless steel). Insulation tip <NUM> may be positioned around a distal tip <NUM> of electrode shaft <NUM>. As shown, insulation tip <NUM> may include an insulation tip lumen 328C, which may be at least partially aligned with an electrode shaft lumen <NUM>. Then, insulation tip <NUM> and electrode shaft <NUM> may be subjected to a fusing cycle. For example, the fusing cycle may include one or more sequences or rounds of heating and cooling to soften insulation tip <NUM> (e.g., formed of a glass). The fusing cycle may at least partially melt insulation tip <NUM> such that a portion of insulation tip <NUM> fuses or bonds to a portion of electrode shaft <NUM>, for example, to form an interface <NUM>. interface <NUM> may be formed on a radially outer portion of the distal portion of electrode shaft <NUM>, and may also be formed on a distal end portion of electrode shaft <NUM>.

Although not shown, electrode shaft <NUM> may include one or more surface contours, which may help secure insulation tip <NUM> to electrode shaft <NUM>. Furthermore, one or more molds or other compression elements may be positioned around insulation tip <NUM> during the fusing cycle, for example, to help shape insulation tip <NUM> and/or couple insulation tip <NUM> to electrode shaft <NUM>. Additionally, although not shown, one or more additional processes may be performed to smooth, shape, or otherwise treat insulation tip <NUM>. Moreover, multiple insulation tips <NUM> may be placed on multiple portions of electrode shaft <NUM>, for example, longitudinally spaced along different portions of electrode shaft <NUM>.

<FIG> illustrates steps of an exemplary method that may be performed to form an electrode <NUM> similar to electrode <NUM>, with similar elements shown by <NUM> added to the reference numbers. For example, electrode <NUM> includes an insulation tip <NUM> on an electrode shaft <NUM>. Insulation tip <NUM> may be a preformed bead or other element formed of a ceramic or other insulating or non-conductive material discussed herein, and electrode shaft <NUM> may be metallic (e.g., stainless steel). Additionally, a coupling element <NUM> may be positioned between insulation tip <NUM> and electrode shaft <NUM>. Insulation tip <NUM> and coupling element <NUM> may be positioned around a distal tip <NUM> of electrode shaft <NUM>. As shown, insulation tip <NUM> may include an insulation tip lumen 428C, which may be at least partially aligned with an electrode shaft lumen <NUM>. Coupling element <NUM> may also include a central lumen to allow for fluid to flow from electrode lumen <NUM> to insulation tip lumen 428C.

Coupling element <NUM> may be formed of a glass bead (e.g., a silicate, a borosilicate, or any biocompatible glass), a ceramic bead, a metal bead, or similar appropriate material. Once insulation tip <NUM> and coupling element are positioned on electrode shaft <NUM>, insulation tip <NUM>, electrode shaft <NUM>, and coupling element <NUM> may be subjected to a fusing cycle. For example, the fusing cycle may include one or more sequences or rounds of heating and cooling. The fusing cycle may at least partially melt coupling element <NUM> such that a portion of coupling element <NUM> fuses or bonds to a portion of electrode shaft <NUM>, for example, to form a first interface 478A. Moreover, the fusing cycle may at least partially melt another portion of coupling element <NUM> such that the other portion of coupling element <NUM> fuses or bonds to a portion of insulation tip <NUM>, for example, to form a second interface 478B. In this aspect, coupling element <NUM> may help couple insulation tip <NUM> to electrode shaft <NUM>.

First interface 478A may be formed on a radially outer portion of the distal portion of electrode shaft <NUM>, and may also be formed on a distal end portion of electrode shaft <NUM>. Second interface 478B may be formed on a radially outer portion of coupling element <NUM>, and may also be formed on a distal end portion of coupling element <NUM>.

As mentioned above, one or more of electrode shaft <NUM> and coupling element <NUM> may include one or more surface contours, which may help secure coupling element <NUM> to electrode shaft <NUM> and/or insulation tip <NUM> to coupling element <NUM>, e.g., to promote formation of first interface 478A and/or second interface 478B. Furthermore, one or more molds or other compression elements may be positioned around insulation tip <NUM> and coupling element <NUM> during the fusing cycle, for example, to help shape insulation tip <NUM> and/or couple insulation tip <NUM>, coupling element <NUM>, and electrode shaft <NUM>. Additionally, although not shown, one or more additional processes may be performed to smooth, shape, or otherwise treat insulation tip <NUM>. Moreover, multiple insulation tips <NUM> and coupling elements <NUM> may be placed on multiple portions of electrode shaft <NUM>, for example, longitudinally spaced along different portions of electrode shaft <NUM>. Furthermore, if insulation tip <NUM> is formed of a ceramic material, a radially inner face (e.g., the portion that abuts coupling element <NUM> at second interface 478B) may be treated (e.g., via a sintering process, a physical vapor deposition process, etc.) to metallize a portion of insulation tip <NUM>. Treating the portion of insulation tip <NUM> may help to improve the strength of the bond between insulation tip <NUM> and coupling element <NUM> at second interface 478B.

<FIG> illustrates a step of an exemplary method that may be performed to form an electrode <NUM> similar to electrode <NUM>, with similar elements shown by <NUM> added to the reference numbers. For example, electrode <NUM> includes an insulation tip <NUM> on an electrode shaft <NUM>. Electrode shaft <NUM> may include one or more surface contours <NUM> and an electrode shaft lumen <NUM>. A sacrificial element <NUM> may be positioned within a portion of electrode shaft lumen <NUM>, for example, to form an insulation tip lumen (not shown). Alternatively, electrode shaft lumen <NUM> may be open, and insulating material <NUM> may cover electrode shaft lumen <NUM>, for example, for treatments that do not require fluid delivery.

Electrode shaft <NUM> may be positioned adjacent to (i.e., in abutting contact) with a supply of insulating material <NUM>. In one aspect, insulating material <NUM> includes a plurality of insulating particles <NUM> (e.g., a powder or beads). Additionally, as discussed below, insulating material <NUM> may include one or more filler materials. A heating element <NUM>, for example, a laser (e.g., a thermal laser, a carbon dioxide laser, a pulse diode laser, etc.) may be directed toward the supply of insulating material <NUM>. Alternatively or additionally, heating element <NUM> may be directed toward a portion of electrode shaft <NUM>. In either aspect, electrode shaft <NUM> may be rotated around a longitudinal axis A while heating element <NUM> is activated. As shown, longitudinal axis A is perpendicular to the direction of the output of heating element <NUM>. Alternatively, electrode shaft <NUM> may be positioned at other angles relative to heating element <NUM> and/or relative to the supply of insulating material <NUM>.

A distal portion of electrode shaft <NUM>, for example, surface contours <NUM>, may contact molten insulating particles <NUM> in the supply of insulating material <NUM>, and insulating particles <NUM> may be entrained or otherwise bonded to electrode shaft <NUM>. Energy from heating element <NUM> may be directed toward the supply of insulating material <NUM>, and electrode shaft <NUM> may be rotated to contact molten insulating particles until a desired amount of insulating material is coupled to electrode shaft <NUM> to form insulation tip <NUM>. Although not shown, additionally processing steps may be performed on insulation tip <NUM>, for example, to cool, smooth, shape, or otherwise treat insulation tip <NUM>. For example, as discussed above, a mold may be used and/or sacrificial element <NUM> may be removed to form an insulation tip lumen, and a portion of insulation tip <NUM> may be heated to smooth the distal end of the formed insulation tip lumen.

<FIG> illustrate additional electrodes 626A and 626B, which are similar to electrode <NUM>, with similar elements shown by <NUM> added to the reference numbers. For example, electrode 626A includes an insulation tip 628A on an electrode shaft 630A, and electrode 626B includes an insulation tip 628B on an electrode shaft 630B. Insulation tips 628A and 628B may be coupled to electrode shafts 630A and 630B via any of the techniques discussed herein. Moreover, as shown, electrodes 626A and 626B include respective filler materials 694A and 694B. For example, insulation tips 628A and 628B may be doped with one or more filler materials 694A or 694B. Filler material 694A may include a powder mixed with the material forming insulation tip 628A, and filler material 694B may include fibers or meshes mixed with the material forming insulation tip 628B.

Filler materials 694A and 694B may help to match an impedance thermal expansion of insulation tips 628A and 628B to an impedance of electrode shafts 630A and 630B, respectively. For example, as discussed above, insulation tips 628A and 628B and electrode shafts 630A and 630B are formed of different materials, which may have different rates of thermal expansion or contraction when heated (e.g., during energy delivery) or cooled. In this aspect, filler materials 694A and 694B may help to adjust a thermal expansion or contraction of insulation tips 628A and 628B to be closer to a thermal expansion or contraction of electrode shafts 630A and 630B, which may help to reduce the risk of separation and/or breakage of insulation tips 628A and 628B from electrode shafts 630A and 630B during the delivery of energy through electrodes 626A and 626B. For example, filler materials 694A and 694B may have thermal expansion coefficients between a thermal expansion coefficient of the material forming insulation tips 628A and 628B (e.g., glass, ceramic, etc.) and a thermal expansion coefficient of the material forming electrode shafts 630A and 630B (e.g., stainless steel).

Filler materials 694A and 694B may be non-conductive or have low conductivity, which at low doping levels does not provide an electrical pathway through the insulating material forming insulation tips 628A and 628B. For example, filler materials 694A and 694B may be formed of tantalum, tungsten, tungsten oxide, platinum, palladium, iridium, gold, etc. Additionally, in some aspects, filler materials 694A and 694B may be radiopaque, which may help a user visualize insulation tips 628A and 628B during a treatment procedure (e.g., via medical imaging, such as an X-ray, an MRI, ultrasound, etc.). Furthermore, filler materials 694A and 694B may be incorporated in any of the aspects discussed herein, for example, within the insulating material <NUM> deposited on an electrode shaft, interspersed within the insulating material <NUM> entrained on a portion of an electrode shaft, etc..

The various electrodes discussed herein are capable of modifying physical properties of tissue when in contact with tissue by delivering energy (e.g., radio frequency energy). The energy delivered may be monopolar or bipolar energy. The various electrodes may be coupled to a shaft, with the shaft configured to extend into a body lumen or cavity of a subject. The shaft includes an electrical element traversing the shaft and connecting the electrode to an energy source, for example, in the handle or coupled to the handle.

As discussed, the electrodes may also be coupled to an actuation member (e.g., movable body <NUM>), for example, in the handle or coupled to the handle, that allows a user to translate the electrode relative to the shaft. The electrode may be translatable between at least a first position in which a cutting shaft (e.g., longitudinal portion <NUM>), of the electrode is retracted within the shaft, and a second position in which the cutting shaft is extended beyond the shaft and exposed. In both the first and second positions, the distal portion that includes the insulated portions (e.g., insulation tip <NUM> or tips with insulating layers forming the exterior layer of the tips) may be extended and exposed beyond the shaft, and not retracted within the shaft. Moreover, the handle may allow for the electrodes to be positioned in one or more intermediate position (i.e., a position in which only a portion of longitudinal portion <NUM> is exposed).

As such, the insulated distal end face (e.g., insulation tip <NUM> or tips with insulating layers forming the exterior layer of the tips) may abut tissue and help to prevent or minimize damage or unintended contact of the electrode with the tissue. The user may also position the uninsulated electrode shaft to abut or contact tissue and apply energy to cut, dissect, ablate, mark, or otherwise treat tissue. The insulation tips may be coupled to the electrode shaft in various ways, which may allow for the insulation tip to be coupled to an existing uninsulated electrode shaft and then used in a procedure.

In one example, an electrosurgical generator coupled to the handle (or within the handle) may generate energy in various modes, for example, radio frequency energy in a cutting mode, a coagulation mode, etc., in order for the electrode to deliver these different modes of energy to the tissue. In one aspect, the electrosurgical generator and/or the handle may include one or more knobs, dials, buttons, etc. in order to select the energy mode. Additionally, in one example, a fluid source (e.g., a saline source) coupled to the handle may provide fluid (e.g., saline) to be delivered through the electrode to the tissue and/or the target site. The fluid may be delivered at a constant rate, a pulsed rate, a user-controlled rate, etc. In these aspects, one or more of the energy delivery and/or the fluid delivery may be controlled by one or more actuators (e.g., triggers, buttons, touch screens, foot pedals, etc.).

Some of the medical devices and methods discussed above allow a user to treat tissue by delivering electrical energy into the tissue, and delivering fluid, either simultaneously or sequentially. For example, a user may couple an electrode to the distal end and deliver the distal end to an interior lumen of a subject to deliver medical therapy in a portion of a procedure (e.g., mark, cauterize, or resect tissue). The insulation tip (or insulating layer forming the exterior of a tip) may help to prevent or reduce damage and/or unintended contact between the electrode and the tissue. The user may also deliver fluid distally out of the distal end of the electrode, either simultaneously or sequentially with the energy delivered, which may help the user to more quickly and efficiently deliver the medical therapy, for example, cut, dissect, ablate, mark, coagulate, cauterize, or otherwise treat tissue. Moreover, the user may deliver fluid and energy without removing the medical device from the patient or subject, which may help to reduce the costs and duration of the procedure, also potentially reducing the risks to the subject.

Additionally, various aspects of the disclosure may allow for insulation tip <NUM> to be formed and coupled to a distal portion of electrode shaft <NUM>. For example, aspects discussed herein may help provide a strong coupling between the conductive material of electrode shaft <NUM> and the non-conductive material of insulation tip <NUM>. Moreover, the formation of insulation tip <NUM> and the coupling of insulation tip <NUM> to electrode shaft <NUM> may be labor and/or cost-effective. Furthermore, in some aspects, the methods of forming and coupling insulation tip <NUM> to electrode shaft <NUM> may help to form insulation tip lumen 28C, for example, such that fluid may be delivered through electrode shaft lumen <NUM> and through insulation tip lumen 28C.

Claim 1:
A method of forming an energy delivery portion of a medical device (<NUM>), the method comprising:
contacting a distal portion (28A) of an electrode shaft (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, 630A, 630B) with an insulating material (<NUM>, <NUM>, <NUM>) in a molten state; and
heating the insulating material to couple the insulating material to the distal portion of the electrode shaft to form an insulation tip (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, 628A, 628B),
wherein the distal portion of the electrode shaft includes one or more surface contours (<NUM>, <NUM>, <NUM>) to entrain the insulating material and wherein the shaft includes an electrode shaft lumen (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>).