Electrosurgical tip

Abstract

To provide an electrosurgical surgical tip including a conductive and low profile cutting surface to provide high current density radio-frequency energy with minimal thermal damage to surrounding tissues.SOLUTION: An electrosurgical surgical tip may include a ring of conductive material sputter-coated around a distal opening of a non-conductive base component and a strip of conductive material sputter-coated along a longitudinal axis of the non-conductive base component.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates generally to the field of medical devices. In particular, the present invention relates to an electrosurgical tip that includes a conductive, low profile cutting surface for delivering high current density radio frequency energy while minimizing thermal damage to surrounding tissue. [Background technology]

[0002] Many endoscopic ultrasound (EUS) guided procedures involve creating a puncture tract (e.g., a fistula) in a tissue layer(s) of a target anatomy using a tissue-penetrating needle, advancing a guidewire through the tissue-penetrating needle to position the distal end of the guidewire within the target anatomy, and then advancing a medical device having a circular electrosurgical tip over the guidewire to dilate the puncture tract. To effectively dilate the tissue layer(s) with minimal thermal damage (e.g., charring, burning, coagulation, etc.), the electrosurgical tip must deliver sufficient current density radio frequency energy through a low surface area profile. Because of these design criteria, conventional electrosurgical tips tend to be expensive and difficult to manufacture.

[0003] With these considerations in mind, a variety of beneficial medical outcomes may be achieved by the devices, systems, and methods of the present invention. Summary of the Invention

[0004] In one aspect, the invention relates to a medical device comprising a non-conductive base component defining a longitudinal axis and a lumen therethrough. A conductive material may be disposed on an outer surface of the non-conductive base component about a distal opening of the lumen. A conductive material may be disposed on the outer surface of the non-conductive base component along the longitudinal axis. The conductive material disposed about the distal opening may include a first layer of conductive material bonded to the non-conductive base component. The conductive material disposed along the longitudinal axis may include a second layer of conductive material bonded to the non-conductive base component. The first and second layers of conductive material may be sputter coated onto the non-conductive base component.

[0005] In the described and other embodiments, one or more of the first and second layers of conductive material may be sputter coated onto the non-conductive base component. A channel may be formed along the longitudinal axis within the outer surface of the non-conductive base component. The second layer of conductive material may extend through the channel. The first and second layers of conductive material may include titanium. The conductive material disposed about the distal opening may further include a third layer of conductive material bonded to the first layer of conductive material, and the conductive material disposed along the longitudinal axis may include a fourth layer of conductive material bonded to the second layer of conductive material. The third and fourth layers of conductive material may be sputter coated onto the respective first and second layers of conductive material. The third and fourth layers of conductive material may include niobium. The conductive material disposed about the distal opening may further include a fifth layer of conductive material bonded to the third layer of conductive material. The conductive material disposed along the longitudinal axis may include a sixth layer of conductive material bonded to the fourth layer of conductive material. The fifth layer of conductive material may include gold. The sixth layer of conductive material may include a nickel-copper alloy. The fifth and sixth layers of conductive material may be sputter coated onto the respective third and fourth layers of conductive material. The fifth layer of conductive material may be brazed to the third layer of conductive material. The sixth layer of conductive material may be sputter coated onto the fourth layer of conductive material. A distal portion of the conductive wire may be soldered to the sixth layer of conductive material.

[0006] In another aspect, the invention relates to a system including a non-conductive base component attached to a distal end of an electrosurgical sheath. The non-conductive base component may include a conductive material applied about a distal opening of the non-conductive base component and a strip of conductive material applied along a longitudinal axis of the non-conductive base component. An access cannula may be positionable within the lumen of the electrosurgical sheath and may extend through the non-conductive base component.

[0007] In other embodiments described, the one or more conductive materials and strips of conductive material may be applied via sputter coating. A channel may be formed along the longitudinal axis in the outer surface of the non-conductive base component. The strips of conductive material may extend through the channel. The channel may be disposed within a distal portion of the electrosurgical sheath. A distal portion of the conductive wire may be disposed within the channel. The distal portion of the conductive wire may be bonded to the channel by using solder. The conductive wire may extend along the electrosurgical sheath and a proximal end of the conductive wire may be connectable to an electrosurgical generator. A guidewire may extend through a lumen of the access cannula.

[0008] In yet another aspect, the invention relates to a medical device comprising a non-conductive base component defining a longitudinal axis and a lumen therethrough. A first layer of conductive material can be disposed about an outer surface of the non-conductive base component in a helical pattern. A second layer of conductive material can be disposed about an outer surface of the non-conductive base component in a helical pattern. The first and second layers of conductive material can be electrically insulated from one another.

[0009] In the described and other embodiments, the first and second layers of conductive material can be the same. The first and second layers of conductive material can be different. The first and second layers of conductive material can be sputter coated onto a non-conductive base component.

[0010] Non-limiting embodiments of the present invention are described by way of example with reference to the accompanying drawings, which are schematic and are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown is typically represented by a single numeral. For clarity, not every component is labeled in every drawing, nor are every component of every embodiment shown unless illustration is necessary to enable those skilled in the art to understand the disclosure. [Brief description of the drawings]

[0011] [Figure 1A] FIG. 2 is a perspective view of an electrosurgical tip, according to one embodiment of the present invention. [Figure 1B] 1 provides a cross-sectional view of various layers of conductive material according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of an electrosurgical tip, according to one embodiment of the present invention. [Figure 3A] FIG. 2 is a perspective view of an electrosurgical tip housed in a physical vapor deposition fixture, according to one embodiment of the present invention. [Figure 3B] FIG. 2 is a perspective view of an electrosurgical tip housed in a physical vapor deposition fixture, according to one embodiment of the present invention. [Figure 4] 3A-3B are schematic diagrams of a fixture (FIGS. 3A-3B) positioned within a physical vapor deposition chamber, in accordance with one embodiment of the present invention. [Figure 5A] 11 is a perspective view of an alternative electrosurgical tip configuration in accordance with an embodiment of the present invention. [Figure 5B] 11 is a perspective view of an alternative electrosurgical tip configuration in accordance with an embodiment of the present invention. [Figure 6] 1 is a perspective view of an electrosurgical system, according to one embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention is not limited to the specific embodiments described herein. The terms used herein are only intended to describe specific embodiments and are not intended to limit the scope of the appended claims. Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0013] Although embodiments of the present invention are described with particular reference to electrosurgical surgical tips comprising one or more layers of conductive metal(s) coated onto a non-conductive ceramic base using physical vapor deposition (PVD), electroless plating, electrolytic plating or brazing, the disclosed devices and methods are not limited to medical or electrosurgical devices and may include a variety of non-conductive devices coated with one or more layers of a variety of conductive materials.

[0014] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. As used herein, the terms "comprising" and / or "comprising" or "including" and / or "comprising" specify the presence of stated features, regions, step elements and / or components, but do not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and / or groups thereof.

[0015] As used herein, the term "distal" refers to the end furthest from the medical professional when introducing the device into a patient, and the term "proximal" refers to the end closest to the medical professional when introducing the device into a patient.

[0016] In various embodiments, the present invention generally relates to a small surface area medical device (e.g., an electrosurgical tip) comprising a layer or layers of conductive material precisely applied / deposited in controlled locations and / or patterns onto a non-conductive (e.g., ceramic) base. The layer(s) of conductive material can provide high current density radio frequency (RF) energy to minimize or prevent collateral thermal damage to surrounding tissue. Components of the medical device adjacent to the layer(s) of conductive material can be electrically and thermally insulating to prevent harm to the patient and / or to prevent thermal damage to the medical device itself.

[0017] 1A, in one embodiment, a medical device 100 (e.g., an electrosurgical tip) of the present invention may include a non-conductive base component 110. The non-conductive base component 110 may comprise a conical or tapered distal portion 118 (e.g., a constant or varying increasing taper or angled surface extending from distal to proximal) and a cylindrical proximal portion 120 (e.g., having a generally constant outer dimension). A lumen 112 may extend along a longitudinal axis of the non-conductive base component 110. The outer dimension of the cylindrical proximal portion 120 may be smaller than the maximum outer dimension of the tapered distal portion 118. A groove or channel 116 may be formed in (e.g., extending along) the outer surface of the non-conductive base component 110 along the longitudinal axis of the proximal portion 120. Additionally, the channel 116 may be formed in (e.g., extending along) the proximal end of the distal portion 118 of the non-conductive base component 110. In various embodiments, the non-conductive base component 110 may comprise various insulating materials, including, but not limited to, ceramic, hard plastic, and the like. A ring 122 (e.g., circular ring, trace, etc.) of conductive material may be disposed on the outer surface of the non-conductive base component 110 around the distal opening 114 of the lumen 112. A strip 124 (e.g., longitudinal strip, trace, etc.) of conductive material may be disposed on the outer surface of the distal and proximal portions 118, 120 along the longitudinal axis of the non-conductive base component 110. A distal end of the strip 124 may intersect, overlap, or contact a portion of the ring 122 to provide a continuous layer of conductive material (e.g., a single / single conductive layer) at or along the outer surface of the distal and proximal portions 118, 120 of the non-conductive base component 110. In various embodiments, a portion of the strip 124 of conductive material may be disposed within (e.g., extend through) the channel 116.

[0018] In one embodiment, the ring of conductive material 122 may include a first layer of conductive material bonded to the non-conductive base component 110, and the strip of conductive material 124 may include a second layer of conductive material bonded to the non-conductive base component 110. The first and second layers of conductive material may be the same material or different materials. In various embodiments, the first and second layers of conductive material may include a metal (e.g., titanium) that provides the advantage of forming / creating a strong atomic bond (e.g., adhesion) with the non-conductive base component 110 (e.g., ceramic). In various embodiments, the first and / or second layers of conductive material may be applied or deposited on the non-conductive base component 110 by using physical vapor deposition (e.g., sputter coating, thermal evaporation, arc spray, etc.), electroless plating, electrolytic plating or brazing, or other coating application.

[0019] In one embodiment, the ring of conductive material 122 may include a third layer of conductive material bonded to a first layer of conductive material, and the strip of conductive material 124 may include a fourth layer of conductive material bonded to a second layer of conductive material. The third and fourth layers of conductive material may be the same or different materials (e.g., different materials from each other and / or different materials from the first and second layers). In various embodiments, the third and fourth layers of conductive material may include a metal (e.g., niobium) that provides the advantage of forming / creating a strong atomic bond (e.g., solderability) with the respective first and second layers of conductive material. In various embodiments, the third and fourth layers of conductive material may be applied or deposited on the non-conductive base component 110 using physical vapor deposition (e.g., sputter coating, thermal evaporation, arc spray, etc.), electroless plating, electrolytic plating or brazing, or other coating application.

[0020] In one embodiment, the ring of conductive material 122 may include a fifth layer of conductive material bonded to the third layer of conductive material, and the strip of conductive material 124 may include a sixth layer of conductive material bonded to the fourth layer of conductive material. The fifth and sixth layers of conductive material may be the same or different materials (e.g., different materials from each other and / or different materials from the first, second, third, and fourth layers). In various embodiments, the fifth layer of conductive material may include a highly conductive metal (e.g., gold) that forms / creates a strong atomic bond with the third layer of conductive material. In various embodiments, the sixth layer of conductive material may include a conductive metal (e.g., nickel-copper alloy) that forms / creates a strong atomic bond with the fourth layer of conductive material and may form a strong atomic bond with a layer of solder (described below). In various embodiments, the fifth and sixth layers of conductive material may be applied or deposited on the non-conductive base component 110 by using physical vapor deposition (e.g., sputter coating, thermal evaporation, arc spray, etc.), electroless plating, electrolytic plating, or brazing, or other coating application. In one embodiment, the layers of conductive material (e.g., first, third, and fifth layers) making up the ring 122 and the layers of conductive material (e.g., second, fourth, and sixth layers) making up the strip 124 may cross (e.g., overlap, touch, abut, etc.) one another in a variety of different patterns, layers, and / or configurations to form a continuous layer of conductive material ( FIG. 1B ). Alternatively, the fifth layer of conductive material may include a compatible filler material 123 (e.g., gold, silver, tin, etc.) that is brazed or welded (e.g., rather than using physical vapor deposition) to the non-conductive base component ( FIG. 2 ), and the sixth layer of conductive material may be applied or deposited on the non-conductive base component 110 by using physical vapor deposition (e.g., sputter coating, thermal evaporation, arc spray, etc.), electroless plating, electrolytic plating, or brazing, or other coating application. In various embodiments, the brazed or welded layer of conductive material may provide a cutting surface with a shape designed for a particular application (e.g., a raised, enlarged, or thicker cutting surface, etc.).

[0021] In various embodiments, the ring 122 of conductive material may be a patient-contacting portion (e.g., a cutting surface) of the medical device 100, and the strip 124 of conductive material may be a non-patient-contacting portion of the medical device. In one embodiment, a distal portion of a conductive wire (not shown) is disposed within the groove 116. The distal portion may be attached to the sixth layer of conductive material by a layer of solder formed within the groove 116 overlying (e.g., covering) the sixth layer of conductive material and the conductive wire disposed between the groove 116. The proximal end of the conductive wire may be electrically connected to an electrosurgical generator, as described below.

[0022] In various embodiments, the inner wall of the lumen 112 may not be coated with a conductive material to thermally and electrically insulate the lumen 112 and any medical devices (e.g., cannula, guidewire, etc.) extending therethrough from the conductive ring 122 and / or strip 124. In various embodiments, the low profile / surface area of ​​the conductive ring 122 and strip 124, as well as the surrounding surfaces of the non-conductive base component 110 (e.g., distal portion 118, proximal portion 120, and lumen 112) may conduct sufficient RF energy to efficiently cut / penetrate various soft tissue walls (stomach, duodenum, gallbladder, pancreas, liver, etc.) while minimizing collateral thermal damage to the surrounding tissue. The ring 122 may be positioned at the most distal portion of the distal portion 118 such that tissue first comes into contact with the ring 122 and is exposed to the RF energy to penetrate the tissue.

[0023] In various embodiments, the layer(s) of conductive material may be applied / deposited onto the non-conductive base component 110 by using a line-of-sight PVD process that uses inert plasma atoms to displace metal atoms from a cathode. With reference to FIGS. 3A-3B, in one embodiment, the non-conductive base component 110 of the present invention may be placed into a fixture 130 that masks the entire exterior surface of the non-conductive base component 110 except for the surfaces to which the ring 122 and strip 124 are to be applied. A plug or blank 132 may be placed into the distal opening 114 of the non-conductive base component 110 to shield the lumen 112 from contact / coating with the atomized metal. Alternatively, the non-conductive base component 110 may be masked with a pre-formed tape, patterned coating, photoresist, or other removable coating to outline the ring 122 and strip 124.

[0024] Referring to FIG. 4, in one embodiment, the fixture 130 may be placed in the sputter chamber 140 such that one side of the fixture 130 is directly opposite the metal target 148a (e.g., the conductive material to be sputtered). The sputter chamber 140 may function as the anode. The metal target 148a may function as the cathode. The inner surface of the sputter chamber 140 may function as the electrode. An inert gas 146 (e.g., argon) may be pumped into the sputter chamber 140 to energize the plasma state and an electric field may be applied to bombard the cathode / metal target 148a. When the plasma atoms contact the metal target 148a, the metal atoms may be displaced from the metal target 148a and directed toward the surface of the fixture 130. A thin layer (e.g., about 50 microns) of sputtered metal 148b may then be formed on the surface of the fixture 130, including the unmasked / exposed portion of the non-conductive base component 110 disposed therein. In various embodiments, the fixture 130 may be rotated within the sputter chamber 140 to expose other unmasked surfaces of the non-conductive base component to the metal target 148a. The process is repeated. Additionally, the metal target 148a may be replaced with a different metal target to apply / deposit various layers of metal to respective portions of the non-conductive base component 110 (e.g., the ring 122 and the strip 124) as described above.

[0025] 6, in one embodiment, the system 200 of the present invention may include a non-conductive base component 110 of a medical device 100 attached to a distal end of a non-conductive electrosurgical sheath 126. In various embodiments, a proximal portion (not shown) of the non-conductive base component 110 may be received / disposed within a distal portion of the electrosurgical sheath 126 such that the channel 116 (not shown) is thermally and electrically insulated from a distal portion (not shown) of a conductive wire disposed therein. The conductive wire may extend along the electrosurgical sheath 126 (e.g., embedded within a sidewall of the electrosurgical sheath) to connect a proximal end of the conductive wire to an electrosurgical generator. An access cannula 129 may extend through a lumen (not shown) of the non-conductive base component 110.

[0026] Various advantages may be realized by the devices, systems, and methods of the present invention. For example, the disclosed layer(s) of conductive material applied / deposited onto the exterior surface of an electrosurgical device using PVD may allow for a wider range of processing conditions at elevated temperatures to provide finer surface features (e.g., lower surface area, lower profile, etc.), thereby reducing manufacturing costs, simplifying manufacturing, minimizing associated thermal damage, and maximizing patient safety. The disclosed PVD process may be applied to new medical devices and / or may reduce the cost of manufacturing or modifying existing medical devices. For example, the manual and expensive processes involved in the manufacture of conventional electrosurgical tips, such as printing a gold bipolar trace in a spiral around a non-conductive tip (Gold Probe™ Boston Scientific Corp., Marlborough, Massachusetts, FIG. 5A) or forming a steel wire around a ceramic tip (Hot Axios™ Boston Scientific Corp., Marlborough, Massachusetts, FIG. 5B), may be modified to apply / deposit a bipolar or monopolar conductive layer by using a PVD process. In various embodiments, for medical applications where a thicker conductive layer may be required, additional layers of conductive material may be applied to the PVD layer by using electroless plating, electrolytic plating, and / or brazing.

[0027] In various embodiments, the order in which the various layers of the aforementioned conductive materials (e.g., titanium, niobium, gold, nickel-copper alloy) may be applied / deposited onto the non-conductive base component may be based on their respective properties, such as adhesive properties to the non-conductive base (e.g., ceramic), solderability (e.g., ability to bond / attach a highly conductive outer / upper layer to an adhesive inner / lower layer), and / or electrical conductivity (e.g., external / tissue contact layer). However, it should be understood that the present invention is in no way limited to these materials / metals, the number of layers of such materials, and / or their deposition order or pattern. As non-limiting examples, various conductive materials, including titanium, niobium, gold, molybdenum, titanium nitride, tantalum, tungsten, platinum, palladium, iridium, tin, nickel, copper, vanadium, silver, zinc, or other biocompatible metals, as well as alloys, oxides, and nitrides of such materials, may be applied / deposited onto the disclosed medical device 100 in various orders / layers, patterns, and / or thicknesses.

[0028] In various additional embodiments, the number of layers of conductive material applied to the non-conductive base component (e.g., ring 122 and / or strip 124) is not limited to the first through sixth layers described above, but may include one layer, two layers, or any number of additional layers.

[0029] In various additional embodiments, the layers of conductive material (e.g., first, third, and fifth layers) that make up ring 122 and the layers of conductive material (e.g., second, fourth, and sixth layers) that make up strip 124 may cross (e.g., overlap, touch, contact) one another in various different patterns, layers, and / or configurations to form a continuous layer of conductive material. For example, a portion of the second layer may overlap a portion of the first layer of conductive material. A portion of the third layer of conductive material may overlap a portion of the second layer of conductive material. A portion of the fourth layer of conductive material may overlap a portion of the third layer of conductive material. A portion of the fifth layer of conductive material may overlap a portion of the fourth layer of conductive material. A portion of the sixth layer of conductive material may overlap a portion of the fifth layer of conductive material.

[0030] All of the devices and / or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present invention. While the devices and methods of the present invention have been described in terms of preferred embodiments, it may be apparent to those skilled in the art that modifications may be applied to the devices and / or methods, and to the steps or sequence of steps of the methods described herein, without departing from the concept, spirit and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the disclosure as defined by the appended claims.

Claims

1. a non-conductive base component defining a longitudinal axis and a lumen therethrough; a conductive material disposed on an outer surface of the non-conductive base component about a distal opening of the lumen; a conductive material disposed on an outer surface of the non-conductive base component along the longitudinal axis; the conductive material disposed about the distal opening includes a first layer of conductive material bonded to the non-conductive base component, and the conductive material disposed along the longitudinal axis includes a second layer of conductive material bonded to the non-conductive base component. Medical equipment.

2. The medical device of claim 1 , wherein one or more of the first and second layers of conductive material are sputter coated onto the non-conductive base component.

3. 3. The medical device of claim 1 or 2, further comprising a channel formed in an outer surface of the non-conductive base component along the longitudinal axis, the second layer of conductive material extending through the channel.

4. The medical device of any one of claims 1 to 3, wherein the first and second layers of conductive material comprise titanium.

5. 5. The medical device of claim 1, wherein the conductive material disposed about the distal opening further comprises a third layer of conductive material bonded to the first layer of conductive material, and the conductive material disposed along the longitudinal axis further comprises a fourth layer of conductive material bonded to the second layer of conductive material, and the third and fourth layers of conductive material are sputter coated onto the first and second layers of conductive material, respectively.

6. The medical device of claim 5 , wherein the third and fourth layers of conductive material comprise niobium.

7. 7. The medical device of claim 5 or 6, wherein the conductive material disposed about the distal opening further includes a fifth layer of conductive material bonded to the third layer of conductive material, and the conductive material disposed along the longitudinal axis includes a sixth layer of conductive material bonded to the fourth layer of conductive material.

8. The medical device of claim 7 , wherein the fifth layer of conductive material comprises gold and the sixth layer of conductive material comprises a nickel-copper alloy.

9. 9. The medical device of claim 7 or 8, wherein the fifth layer of conductive material is brazed to the third layer of conductive material and the sixth layer of conductive material is sputter coated onto the fourth layer of conductive material.

10. The medical device of any one of claims 7 to 9, further comprising a distal portion of a conductive wire soldered to the sixth layer of conductive material.

11. a non-conductive base component attached to a distal end of an electrosurgical sheath, the non-conductive base component including a conductive material applied about a distal opening of the non-conductive base component and a strip of conductive material applied along a longitudinal axis of the non-conductive base component; an access cannula positionable within a lumen of the electrosurgical sheath and extendable through the non-conductive base component; system.

12. The system of claim 11 , wherein one or more of the conductive material and the strips of conductive material are applied via sputter coating.

13. 13. The system of claim 11 or 12, further comprising a channel formed in an outer surface of the non-conductive base component along the longitudinal axis, the strip of conductive material extending through the channel.

14. The system of claim 13 , wherein the channel is disposed in a distal portion of the electrosurgical sheath.

15. The system of claim 13 or 14, further comprising a distal portion of a conductive wire disposed within the channel.

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