Electrode assembly including plated emitters

Abstract

An electrode assembly includes an elongated body, a proximal emitter, and a distal emitter. A discharge port can be in fluid communication with an internal lumen of the elongated body. The proximal and distal emitters are formed by plating a metal onto an outer surface of the elongated body of a polymer. A portion of the elongated body forms an insulating partition between the proximal and distal emitters. A distal cap can be connected to the elongated body, formed of a conductive material, and arranged to be in electrical communication with the distal emitter. A distal lead, thermocouple, and / or hypotube can be disposed within the internal lumen to form an electrical pathway with the distal cap. A sheath can be disposed over a portion of the proximal emitter, and a radiopaque marker can be connected to the proximal emitter. Methods of manufacturing the electrode assembly are also disclosed.

Description

[0001] Priority requirements

[0002] This application claims priority and all benefits to U.S. Provisional Patent Application No. 62 / 993,317, filed March 23, 2020, the entire contents of which are incorporated herein by reference. Background Technology

[0003] Ablation systems are commonly used to selectively destroy neural tissue so that pain signals are no longer transmitted to the brain. For example, the electrode assembly of an ablation system directs energy to the tissue to heat and destroy its cells. Another example includes ablating tumors in the liver, kidneys, lungs, and bones. Some ablation systems utilize fluids to improve energy transfer across the interface between the electrode assembly and the tissue.

[0004] When the pathology is intraosseous, such as a bone tumor, the guide assembly can help position the electrode assembly at a target location within the bone. In some cases, the guide assembly may need to provide a curve to access bone tumors in difficult anatomical locations. One example includes tumors located in the posterior part of the vertebral body of the spine. Many known electrode assemblies, especially those requiring one or more lumens within them to have flushing capabilities, cannot adequately follow the curve of the guide assembly without compromising their function. Furthermore, many known electrode assemblies are complex in construction, thus increasing manufacturing and assembly costs and the potential risk of component failure. Therefore, there is a need in the art for an electrode assembly for ablation systems that overcomes one or more of the aforementioned disadvantages. Summary of the Invention

[0005] The electrode assembly disclosed herein facilitates the treatment of tissues in anatomical locations that are difficult to access with conventional devices. More specifically, the flexibility of the elongated body of the electrode assembly provides access to anatomical locations requiring greater flexibility and / or a sharper radius of curvature, and also provides infusion fluid to the anatomical location. The electrode assembly includes an elongated body, a distal emitter, and a proximal emitter electrically insulated from the distal emitter, such that the electrode assembly is structurally bipolar. The elongated body may be a monolithic construction and formed of a flexible material. The elongated body may include a continuous portion proximal to the proximal emitter, between the distal and proximal emitters, and distal to the distal emitter. The elongated body includes an outer surface and may also include at least one inner surface defining at least one lumen. In some embodiments, the elongated body is polymeric, in other words, at least partially formed of a polymer. The elongated body may be a tube extruded from polyetheretherketone (PEEK). A first lumen may be configured to guide infusion fluid from a fluid source to a discharge port. The discharge port may be defined or located on the near emitter, or defined by a portion of the elongated body forming the insulating spacer. The cavity may be optional, and the cross-section of the elongated body may be solid. The first cavity may be in fluid communication with the discharge port. The first cavity may extend longitudinally through the discharge port to near the distal end of the elongated body. The distal end of the elongated body may be end-closed or plugged with a distal cap.

[0006] Far and near emitters are attached to or disposed on an elongated body. The far and near emitters can be formed by plating a conductive material onto the outer surface of the polymer elongated body. The far emitter can be formed by plating metal onto a first portion of the outer surface, and the near emitter can be formed by plating the same metal or another metal onto a second portion of the outer surface. The first and second portions can be axially spaced apart from each other, such that a portion of the elongated body forms an insulating spacer between the near and far emitters. The far and near emitters are electrically connected to a conductor for detachable connection to an energy source. An electrode assembly includes a first electrical path electrically connected to the far emitter. A thermocouple can be arranged to measure the temperature near the distal end of the electrode assembly. The elongated body can define a second cavity fluidly separated from the first cavity, wherein the first electrical path and / or the thermocouple is disposed within the second cavity. The first electrical path can be a distal lead or a metal plated on the inner surface defining the second cavity. The thermocouple can be fastened to the elongated body at or near its distal end.

[0007] The distal cap can be attached to the elongated body and can also be secured to the elongated body in a way that seals the interior cavity. The distal cap can be formed of a conductive material and arranged to be electrically connected to the remote transmitter. The distal cap can form part of a first electrical path to transfer radio frequency (RF) energy to the remote transmitter. The distal cap can be formed of soldered metal and is therefore conductive, or a conductive adhesive can be applied at the interface between the distal cap and the elongated body, the distal cap being formed of metal.

[0008] A remote transmitter can be disposed on the distal end of an elongated body. A first portion of the remote transmitter can be plated on the outer surface of the elongated body, and a second portion of the remote transmitter can be plated on the surface forming the distal end of the elongated body. The second portion is electrically connected to the first portion. The proximal surface of the remote cap is fastened in a manner electrically connected to the second portion of the remote transmitter. The fastening of the remote cap can be performed to not only block the first and second cavities but also to secure the thermocouple leads in place. The remote cap is formed of a conductive material and can also be formed of a material with sufficient thermal conductivity to effectively transfer heat to be sensed by the thermocouple leads. The thermocouple can also be configured to transfer RF energy to the remote transmitter via the remote cap. A third portion of the remote transmitter can be plated on a portion of the inner surface near the distal end of the elongated body. The third portion is electrically connected to both the second and first portions. The remote cap can be at least partially disposed or recessed within the first cavity to be electrically connected to the third portion. The entire distal cap can be disposed within the first inner cavity such that the distal surface of the distal cap substantially coincides with the distal end of the elongated body. The side surface of the distal cap is fastened to the third portion of the remote transmitter. The distal cap may include a proximal cap portion disposed within the inner cavity. The proximal cap portion may be electrically connected to the submersible tube and the remote transmitter to form part of a first electrical path. The arrangement of a portion of the distal cap disposed within the inner cavity includes the side surface fastened to the third portion 98 of the remote transmitter.

[0009] The thermocouple leads can be disposed within the hypotube. The hypotube can be coaxially disposed within a first inner cavity. An annular gap between the hypotube and the inner surface of the elongated body can be in fluid communication with a discharge port. The thermocouple leads can be fluidly separated from the infusion fluid. The hypotube may include a distal end fastened to a distal cap. The distal end of the hypotube may be end-closed and its size and shape complementary to a portion of the proximal surface of the distal cap. The hypotube may be formed of a conductive material. The hypotube can be electrically connected to a conductor and is also configured to transfer RF energy to a remote transmitter via the distal cap. A shroud, which may be formed of a non-conductive material, can be disposed between the distal end of the hypotube and the distal cap. The shroud can be configured to electrically insulate the hypotube from the distal cap while not restricting thermal conduction.

[0010] The electrode assembly also includes a second electrical path electrically connected to the proximity transmitter. The second electrical path is configured to transfer RF energy to the proximity transmitter. The second electrical path can be formed by plating metal, leads, etc., onto an inner surface defining a first cavity. The electrode assembly may include a sheath formed of a non-conductive material. The second electrical path may extend between an elongated body and a sheath. The sheath may be a heat-shrink tubing, while the second electrical path is defined by a plated conductor or a proximal lead extending from the proximity transmitter. The second electrical path and the sheath may extend proximally along the entire length of the elongated body or a portion thereof.

[0011] The electrode assembly may include at least one radiopaque marker with sufficient radiometric density for visualization on X-ray imaging. The radiopaque marker can be attached at any suitable location along the elongated body. The radiopaque marker may be a band attached to the near emitter. The radiopaque marker may be positioned on the distal side of the sheath to allow visualization of the near emitter on X-ray imaging. The radiopaque marker may form part of a second electrical path. The radiopaque marker is attached to the near emitter, or the band secures the near-side lead to the near emitter. The distal cap is formed of a conductive material and can be readily visualized on X-ray imaging to allow visualization of the distal emitter.

[0012] According to certain aspects of this disclosure, an improved method of manufacturing an electrode assembly is provided. An elongated body may be formed to define at least one inner cavity. The elongated body may be extruded to form a polymer tube (e.g., PEEK) segment. A discharge port may be removed from the elongated body, the discharge port being in fluid communication with the inner cavity. A near emitter and a far emitter may be plated onto the polymer tube. A first layer of copper or nickel may be adhered to the polymer tube, and a second layer of gold or platinum may be plated onto the first layer. The near emitter and the far emitter are separated by a portion of the polymer tube forming an insulating spacer. The far emitter is also plated to the distal end of the elongated body, and a distal cap is fastened to the distal end of the elongated body to be in electrical communication with the far emitter. The far emitter may be further plated to the inner surface of the elongated body defining the inner cavity, and the distal cap includes a proximal portion disposed within the inner cavity and fastened to the inner surface. The distal cap is conductive and may be soldered.

[0013] The method may include connecting a thermocouple to a distal cap. The thermocouple may be inserted into a hypotube, and the distal end of the hypotube may be crimped to the thermocouple lead to form a thermocouple assembly. The thermocouple assembly may be guided through the lumen and secured to the distal cap. A sheath or adhesive may be disposed between the thermocouple and the hypotube, wherein the sheath or adhesive is electrically insulating but thermally conductive. The hypotube may be arranged in electrical communication with a conductor. Alternatively, the distal lead may be secured to the distal cap. The distal cap may be formed with solder for a relatively small area of ​​the distal lead, and then the distal cap itself is covered with a non-conductive adhesive.

[0014] The method may also include arranging a proximal lead in electrical communication with the proximal emitter. The proximal lead can be formed by plating metal onto an elongated body or by forming discrete proximal conductors, such as wires. A sheath can be disposed on the electrical path and optionally on a portion of the proximal emitter. The sheath can be a heat-shrinkable tube on a portion of the proximal emitter. A radiopaque marker can be attached to the proximal emitter. The radiopaque marker can be positioned adjacent to the sheath. The radiopaque marker can be a band crimped or forged onto the proximal lead. A distal cap is formed of a conductive material, while the radiopaque markers provide visual markers for displaying the distal and proximal emitters on X-ray imaging, respectively. The electrode assembly can be arranged in a kit with the access sleeve and introducer device. The result is a lower-cost, potentially disposable electrode assembly that provides improved flexibility for infusion, allowing access to anatomical locations with greater flexibility and / or a sharper radius of curvature. Attached Figure Description

[0015] The advantages of the invention will be better understood and readily apparent when considered in conjunction with the accompanying drawings and with reference to the following detailed description. It should be understood that the drawings are illustrative in nature and are not necessarily drawn to scale.

[0016] Figure 1 It is a perspective view of an ablation system including the electrode assembly.

[0017] Figure 2 yes Figure 1 Detailed view of the electrode assembly, part 2.

[0018] Figure 3 yes Figure 1 A front view of a portion of the electrode assembly.

[0019] Figure 4 yes Figure 3 A cross-sectional view of a portion of the electrode assembly.

[0020] Figure 5 yes Figure 3 An axial view of a portion of the electrode assembly taken along line 5-5.

[0021] Figure 6 This is a cross-sectional view as part of another embodiment of the electrode assembly.

[0022] Figure 7 This is a cross-sectional view as part of another embodiment of the electrode assembly.

[0023] Figure 8 This is a cross-sectional view as part of another embodiment of the electrode assembly.

[0024] Figure 9 This is a cross-sectional view as part of another embodiment of the electrode assembly.

[0025] Figure 10 This is a cross-sectional view as part of another embodiment of the electrode assembly.

[0026] Figure 11 This is a schematic representation of a vertebra, in which an electrode assembly is deployed together with an implant assembly to ablate intraosseous tumors or basal vertebral nerves. Detailed Implementation

[0027] refer to Figure 1 The ablation system includes an electrode assembly 12 configured for treating tissue. The electrode assembly 12 includes an elongated body 22 having a length defined between a proximal end 16 opposite to a distal end 20. Near the distal end 20 of the elongated body 22, the electrode assembly 12 includes a distal emitter 38 and a proximal emitter 40 positioned proximal to the distal emitter 38. The distal emitter 38 and the proximal emitter 40 may be electrically insulated from each other, such that the electrode assembly 12 is structurally bipolar. Aspects of this disclosure can be provided for monopolar electrode assemblies requiring a grounding source, such as a grounding pad.

[0028] Electrode assembly 12 includes at least one conductor 50 electrically connected to far and near transmitters 38, 40, and a connector 52 electrically connected to conductor 50. Connector 52 is configured for detachable connection to an energy source 54, such as an electrosurgical generator. A suitable energy source 54 is a radio frequency generator and control console sold by Stryker Corporation (Kalamazoo, Mich.) under the trade names MultiGen (MG1) and MultiGen2 (MG2), and those described in jointly owned international publication WO 2018 / 0200254, published November 1, 2018, the entire contents of which are incorporated herein by reference. Energy source 54 may be capable of supplying a variable current to electrode assembly 12. Control console may allow adjustment of the frequency, current, and / or voltage level of the source current for different time periods. Energy from energy source 54 is delivered to far and near transmitters 38, 40 such that far and near transmitters 38, 40 have opposite polarities. When positioned within or adjacent to tissue, the energy passing between the far and near emitters 38, 40 helps to heat and ablate the tissue, or alternatively, electrosurgically cut or coagulate it.

[0029] As mentioned, conventional electrode assemblies, especially those with fluid infusion, flushing, or internal cooling, typically cannot achieve a minimum curvature. These electrode assemblies cannot obtain sufficient posterior access within the vertebral body via a unipedicular approach, or other procedures requiring off-axis positioning. The electrode assembly 12 of this disclosure advantageously provides a highly flexible elongated body 22. Furthermore, the elongated body 22 can extend near or beyond the distal end 20 of the electrode assembly 12, such that almost the entire length of the elongated body 22 is flexible. In other words, the elongated body 22 can be a monolithic construction made of a flexible material and extend at least to the distal side of the near emitter 40, and in some cases to the distal side of the far emitter 38. For example, Figure 3 The elongated body 22 is shown to have continuous portions on the proximal side of the near emitter 40, between the far emitter 38 and the near emitter 40, and on the distal side of the far emitter 38. In an alternative embodiment, the elongated body 22 is contemplated to be formed from more than one sub-component. Due to its flexibility, the elongated body 22 is configured to bend or flex in a manner further described when deployed through the introducer assembly 13 (see [link to documentation]). Figure 11 ).

[0030] The elongated body 22 may define the distal end 20 of the electrode assembly 12, and the elongated body 22 may define the proximal end 16. In some embodiments, the electrode assembly 12 includes a hub 23 (see...). Figure 11 Meanwhile, the slender body 22 extends distally from the hub 23. Now refer to Figure 3 and 4 The elongated body 22 includes an outer surface 72 and may also include at least one inner surface 70 defining at least one cavity 34, 35 to be described. In some embodiments, the elongated body 22 is polymeric, in other words, at least partially formed of a polymer. The elongated body 22 can be extruded, molded, or formed using other suitable manufacturing techniques and can be formed from films, fibers, fabrics, and powders. In one example, the elongated body 22 is a tube extruded from polyetheretherketone (PEEK), which is highly flexible and includes material properties very suitable for medical devices. Furthermore, in embodiments having more than one cavity 34, 35, extruding a PEEK tube can reduce manufacturing complexity and cost compared to known devices. Other suitable materials, such as polytetrafluoroethylene (PTFE), are also considered. TM Materials include phenolic resins, polycarbonate, polysulfide, and polyoxymethylene. Suitable materials may include Young's modulus less than 3.6 gigapascals (GPa).

[0031] Far and near emitters 38, 40 are attached to or disposed on the elongated body 22. More specifically, the far and near emitters 38, 40 can be formed by plating a conductive material onto the outer surface 72 of the polymer elongated body 22. An exemplary plating process includes plating a metal onto the polymer elongated body 22, which is composed of... Figure 1-3 The dots in the diagram are schematically represented. SAT Plating (Troy, Mich.) has developed a suitable manufacturing process for plating metal onto polymers. In one example, the metal is gold; other suitable metals include copper, nickel, stainless steel, titanium, and chromium. For example, a first layer of copper or nickel can be adhered to the polymer tube, and a second layer of gold or platinum can be plated on top of the first layer. Plating metal onto the polymer material causes the near and far transmitters 38, 40 to conduct electricity for transmitting radio frequency energy without adversely affecting the flexibility of the elongated body 22. Other suitable methods for plating near and far transmitters include electroless plating, electrodeposition, immersion, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma spraying, etc.

[0032] As mentioned, the far emitter 38 is spaced apart from and electrically insulated from the near emitter 40, which is necessary for the electrode assembly 12 to function as a bipolar electrode. The far emitter 38 can be formed by plating metal onto a first portion 56 of the outer surface 72, and the near emitter 40 can be formed by plating the same metal or another metal onto a second portion 58 of the outer surface 72. The first portion 56 and the second portion 58 can be axially spaced apart from each other, such that a portion of the elongated body 22 forms an insulating spacer 42 between the near and far emitters 38, 40. For example, in an embodiment where the elongated body 22 is a PEEK tube, the PEEK tube itself is non-conductive and thus forms the insulating spacer 42 between the near and far emitters 38, 40. The near and far emitters 38, 40 are therefore electrically insulated, eliminating the need for separate insulating spacers that might require mechanical connection with adhesives, threads, lap joints, etc. In addition to the increased flexibility and reduced manufacturing complexity and cost as previously described, this arrangement eliminates the interface between discrete components and the corresponding possibility of infusion fluid flowing out through that interface, especially when the electrode assembly 12 is bent at larger bending angles and with sharper curvatures. Otherwise, fluid outflow at the interface could cause a dummy electrode to remain "inside" the device during operation, which could impair its function. The electrode assembly 12 of this disclosure overcomes this drawback.

[0033] The first inner cavity 34 can be configured to guide infusion fluid from a fluid source (not shown) to a discharge port 44. The discharge port 44 can be located at any suitable location along the length of the elongated body 22, and more than one discharge port 44 can be provided. Figure 2-4 The discharge port 44, defined by or located on the near emitter 40, is shown. Figure 5-10 The discharge portion, defined by the portion of the elongated body 22 forming the insulating spacer 42, is shown, i.e., between the proximal and distal emitters 38, 40. Positioning the discharge port 44 proximal to the distal emitter 38 when the electrode assembly 12 is deployed within the anatomical structure at a proximity angle can advantageously allow the infused fluid to descend along the surface of the distal emitter 38 under the influence of gravity. For example, micro-infusion of fluids (e.g., saline or other conductive fluids) using a micro-infusion module (not shown) facilitates energy transfer across the tissue-emitter interface, which helps control temperature, impedance, hydration, and ion concentration to prevent biochemical carbonization. A suitable micro-infusion module is disclosed in co-owned International Publication WO 2020 / 0198150, published November 5, 2020, the entire contents of which are incorporated herein by reference. The micro-infusion module can be releasably connected to the electrode assembly 12, for example, using a Luer lock connector connected to the fluid connector 36 (see...). Figure 1 The micro-infusion module can be considered "miniature" because of its relatively small shape factor and / or the ability to infuse a certain amount of fluid at a relatively low rate. However, it should be understood that the cavities 34, 35 are optional, and the cross-section of the elongated body 22 can be solid. The resulting electrode assembly may not provide infusion, and electronic sub-components may be arranged along the outer surface 72 of the elongated body 22. One or more sheaths may be provided, if necessary, to electrically insulate certain components.

[0034] The first inner cavity 34 is in fluid communication with the discharge port 44 and can be arranged in any suitable manner within the elongated body 22. For example, Figure 4 The first inner cavity 34 extends longitudinally within a portion of the elongated body 22 and further turns radially outward toward the discharge port 44. Figure 6-10 The first inner cavity 34 extends longitudinally, passes through the discharge port, and reaches the vicinity of the distal end 20 of the elongated body 22. In embodiments where the first inner cavity 34 extends to the distal side of the discharge port 44, the distal end 20 of the elongated body 22 may be formed as end-closed. Figure 4 ) or use the distal cap 46, which will be described in detail below. Figure 6-10 ) plug it. For example, Figure 4 The distal end 20 of the elongated body 22 shown may be formed by a catheter tipping process, wherein heat is applied to at least partially round, tip, or close the distal end 20 of the elongated body 22. Alternatively, the distal end 20 may define an exhaust port 44 or another exhaust port. Figure 6-10The cavities 34 and 35 extend to the distal end 84 of the elongated body 22, with the distal cap 46 connected to the distal end 84 of the elongated body 22. This arrangement allows the cavities 34 and 35 to extend along the entire length of the elongated body 22, where the axial cross-section of the elongated body 22 is constant, and the form factor is particularly well-suited to the extruded elongated body 22. This is itself a less complex and more cost-effective manufacturing process for smaller devices of 22-gauge, 14-gauge, and similar specifications, as is the case in some embodiments. Similarly, the fabrication of multi-cavity tubes can also be accomplished by extrusion in an efficient manner. Other suitable manufacturing techniques may include vacuum forming, injection molding, blow molding, additive manufacturing, braiding, etc.

[0035] The far and near emitters 38 and 40 are electrically connected to conductor 50 for detachable connection to energy source 54. To facilitate this electrical connection, electrode assembly 12 includes a first electrical path 76 electrically connected to far emitter 38. Furthermore, electrode assembly 12 may include a thermocouple 62 arranged for measuring the temperature near the distal end 20 of electrode assembly 12. Figure 4 The diagram is schematically shown and in Figure 6-10 The leads 80 and 82 are depicted in the middle. The control console can be configured to regulate the transmitted RF energy based on the temperature measured by the thermocouple 62 and other measured parameters. The elongated body 22 can define a second cavity 35 fluidly separated from the first cavity 34, wherein the first electrical path 76 and / or the thermocouple 62 are disposed within the second cavity 35. (Continue to reference) Figure 4 A first electrical path 76 may extend through the second cavity 35 to be in electrical communication with the distal transmitter 38. For example, the first electrical path 76 may be a distal lead 92, or metal plated on the inner surface 70 defining the second cavity 35. An orifice (not shown) may extend from the inner surface 70 to the outer surface 72 to provide electrical communication between the first electrical path 76 within the second cavity 35 and the distal transmitter 38 on the outer surface 72. Thermocouple 62 may be secured to the elongated body 22 at or near the distal end 20 using any suitable connection means. In some embodiments, one or more additional thermocouples (not shown) may be positioned near the proximal transmitter 40. The additional thermocouples may be configured to monitor the progression of ablation damage at locations closer to the distal end 20 of the electrode assembly 12. The control console may be configured to regulate the transmitted RF energy based on the temperature measured by the additional thermocouples.

[0036] The multi-cavity arrangement prevents potential damage to electronic components and the infused fluid. Furthermore, since the elongated body 22 itself provides a barrier separating the first cavity 34 from the second cavity 35, the flexibility of the elongated body 22 is hardly compromised, and there are fewer concerns about damage to the internal sub-components or the interfaces between them.

[0037] Now for reference Figure 6-10 The distal cap 46 can be connected to the elongated body 22. The distal cap 46 can define the distal end 20 of the electrode assembly 12. The distal cap 46 can be fastened to the elongated body 22 in a way that seals the cavities 34, 35. Furthermore, the distal cap 46 can be formed of a conductive material and arranged to be electrically connected to the remote transmitter 38. As further described, the distal cap 46 can form part of a first electrical path 76 to transfer RF energy to the remote transmitter 38. The distal cap 46 can be arranged to be electrically connected to the remote transmitter 38 positioned on the outer surface 72 of the elongated body 22, wherein the distal lead 92 (and / or thermocouple 62) is disposed within the cavities 34, 35. In such an arrangement, the electronics of the electrode assembly 12 can be inside the elongated body 22 while still transferring the necessary RF energy to the remote transmitter 38 on the outside of the elongated body 22. In one example, the distal cap 46 itself is formed of solder metal and is therefore conductive, while in another example, a conductive adhesive may be applied at the interface between the distal cap 46 and the elongated body 22, wherein the distal cap 46 is formed of metal. In some embodiments, the distal cap 46 may be formed of a non-thermally and non-conductive material. For example, the distal cap 46 may have solder formed on a relatively small area for the distal lead 92, after which the distal cap 46 itself is covered with a non-conductive adhesive.

[0038] Figure 6 An embodiment of the electrode assembly 12 is illustrated, wherein a portion of the far emitter 38 is disposed on the distal end 84 of the elongated body 22. More specifically, a first portion 86 of the far emitter 38 is plated on the outer surface 72 of the elongated body 22, and a second portion 88 of the far emitter 38 is plated on the surface forming the distal end 84 of the elongated body 22. The second portion 88 is electrically connected to the first portion 86 and can be considered as a lip extending radially inward around the distal end 84 of the elongated body 22. The proximal surface 48 of the distal cap 46 is fastened in such a manner that it is electrically connected to the second portion 88 of the far emitter 38. The welded metal itself may include the aforementioned proximal surface 48 after curing, or alternatively, the distal cap 46 may be a discrete metal component including the aforementioned proximal surface 48.

[0039] Figure 6The embodiment further illustrates an elongated body 22 defining a first inner cavity 34 and a second inner cavity 35 fluidly separated from the first inner cavity 34. Leads 80, 82 of thermocouple 62 extend through the second inner cavity 35 and are secured to a distal cap 46. Welding of the distal cap 46 can be performed to not only block the first and second inner cavities 34 and 35, but also to secure the leads 80, 82 of thermocouple 62 in place. Alternatively, the leads 80, 82 can be secured to the distal cap 46 by adhesives, crimping, friction fitting, etc. The distal cap 46 is formed of a conductive material and can also be formed of a material with sufficient thermal conductivity. For example, the distal cap 46 effectively transfers heat from the ablated adjacent tissue, and the heat is sensed by the thermocouple 62 leads 80, 82, which are themselves conductive. An electrical signal indicating temperature is transmitted from the thermocouple 62 to a control panel. Furthermore, since the leads 80, 82 of thermocouple 62 are conductive, in some embodiments it is contemplated that thermocouple 62 could be further configured to transfer RF energy to the remote transmitter 38 via the distal cap 46. In such an arrangement, the first electrical path 76 may not require the distal lead 92 for transferring RF energy from conductor 50 to the remote transmitter 38 (see [link to original text]). Figure 3 and Figure 8 ).

[0040] Now for reference Figure 7 The diagram illustrates another embodiment of the electrode assembly 12, in which a hypotube 90 is provided, with leads 80, 82 disposed within the hypotube 90. Figure 6 An elongated body 22 defining the first and second cavities 34, 35 is shown. Figure 7 A single inner cavity (first inner cavity 34) is shown, in which the thiocyanate tube 90 is coaxially disposed. In this arrangement, the first inner cavity 34, specifically the annular gap between the thiocyanate tube 90 and the inner surface 70 of the elongated body 22, is in fluid communication with the discharge port 44. The leads 80, 82 of the thermocouple 62 are fluidly separated from the infusion fluid.

[0041] The hysteresis tube 90 may include a distal end 94 fastened to a distal cap 46, for example, with solder, adhesive, etc. Furthermore, a first portion 86 of the distal transmitter 38 is plated on the outer surface 72 of the elongated body 22, and a second portion 88 of the distal transmitter 38 is plated on the surface forming the distal end 84 of the elongated body 22, while the first and second portions 86, 88 are electrically connected to the distal cap 46. The distal end 94 of the hysteresis tube 90 may be end-closed as shown, and in one example, a portion of the proximal surface 48 of the distal cap 46 is hemispherical, as is the distal end 94 of the hysteresis tube 90, with complementary dimensions and shapes. The hysteresis tube 90 may be formed of a conductive material, such as stainless steel. In some embodiments, it is envisioned that the hysteresis tube 90 may be electrically connected to a conductor 50 and further configured to transmit RF energy to the distal transmitter 38 via the distal cap 46. In such an arrangement, the first electrical path 76 may not require a distal lead 92 to transmit RF energy to the distal transmitter 38 (see [link to documentation]). Figure 3 and 8 It should also be understood that the thiopanle 90 can be formed to have sufficient flexibility to not restrict the flexibility of the elongated body 22. Since the thiopanle 90 is formed of a conductive material, a shield 96 formed of a non-conductive material can be disposed between the distal end 94 of the thiopanle 90 and the thermocouple 62. The shield 96 can be configured to electrically insulate the thiopanle 90 from the thermocouple 62 while not restricting thermal conduction between them. Examples of materials suitable for the shield 96 may include thermal adhesives or heat-shrinkable materials.

[0042] Figure 8 An embodiment of the electrode assembly 12 is shown, wherein a first portion 86 of the far emitter 38 is plated on the outer surface 72 of the elongated body 22, a second portion 88 of the far emitter 38 is plated on the surface forming the distal end 84 of the elongated body 22, and a third portion 98 is plated on the portion of the inner surface 70 near the distal end 84 of the elongated body 22. The third portion 98 is electrically connected to the second portion 88 and to the first portion 86, and the far emitter 38 can be considered to be in a generally cylindrical form. The illustrated embodiment shows the first portion 86 extending a greater distance proximally from the distal end 84 of the elongated body 22 than the third portion 98; however, alternative relative dimensions are conceivable.

[0043] The third part 98 is disposed within the first inner cavity 34, and the distal cap 46 may be at least partially disposed within or recessed into the first inner cavity 34 to be electrically connected to the third part 98 (see also...). Figure 9 and 10 ). Figure 8The entire distal cap 46 is shown disposed within the first inner cavity 34 such that the distal surface of the distal cap 46 nearly coincides with the distal end 84 of the elongated body 22. The side surface 100 of the distal cap 46 is fastened to the third portion 98 of the distal emitter 38. The welded metal itself may include the side surface 100 after curing, or alternatively, the distal cap 46 may be a discrete metal component including the side surface 100.

[0044] Figure 8 The embodiment also shows an elongated body 22 defining a first cavity 34, wherein leads 80, 82 of the thermocouple 62 and distal leads 92 of the electrical path 74 are disposed within the first cavity 34. It should be understood that leads 80, 82, 92 may be disposed within a shield or sheath (not shown) to electrically insulate the electronic components from the infusion fluid. It should also be understood that the distal cap 46 of this embodiment can be used in conjunction with the hypotube 90, the elongated body 22 having first and second cavities 34, 35, and / or any other compatible embodiment of this disclosure.

[0045] Figure 8 The distal cap 46, located within the inner cavity 34, is shown. Figure 9 and Figure 10 The distal cap 46 is shown to be dome-shaped and also includes a proximal cap portion 102 disposed within the cavity 34. In one embodiment, the distal cap 46 can be more easily welded into the cavity 34 compared to repeatedly welding the dome-shaped end. The proximal cap portion 102 can be electrically communicated with the hypotube 90 and the remote transmitter 38 to form part of a first electrical path 76. The arrangement of a portion of the distal cap 46 disposed within the cavity 34 includes a side surface 100 fastened to a third portion 98 of the remote transmitter 38. Among other advantages, the interface between the side surface 100 and the third portion 98 is subjected to shear forces different from tensile forces and provides a more robust design to accommodate fluid under pressure. The infused fluid can be at a pressure of approximately one (1) bar, but the distal cap 46 can be configured to accommodate greater pressures.

[0046] The first electrical path 76 is configured to transfer RF energy to the far transmitter 38. The electrode assembly 12 also includes a second electrical path 78 electrically connected to the near transmitter 40 and configured to transfer RF energy to the near transmitter 40. (See again...) Figure 4The second electrical path 78 traverses the bend defined by the first cavity 34 to be connected to the near emitter 40. The second electrical path 78 can be formed by plating metal, leads, etc., on the inner surface 70 defining the first cavity 34. The first electrical path 76 should be insulated from the second electrical path 78, but since it extends axially through the near emitter 40, it may be desirable to position the first electrical path 76 inside the elongated body 22. In other words, unlike the distal lead 92 which extends along the outer surface 72 of the elongated body 22 across the near emitter 40, for example, by placing the first electrical path 76 within the cavities 34, 35, concerns about arcing or electrical damage can be reduced. This concern is less apparent for the near emitter 40 because the lead extending proximally from the near emitter 40 does not electrically connect to the distal emitter 38 in any way. However, it is conceivable that the near emitter 40 could be C-shaped to define a gap (not shown), through which the distal lead 92 extends in an electrically insulated manner from the near emitter 40.

[0047] Now for reference Figure 7-10 The electrode assembly 12 may include a sheath 104 formed of a non-conductive material. A second electrical path 78 may extend between the elongated body 22 and the sheath 104. In some embodiments, the sheath 104 is a heat-shrink tubing, wherein the second electrical path 78 is defined by a plated conductor or a proximal lead 108 extending from the near-emitter 40. Figure 7-9 The plated conductor is shown, which can be considered as the portion of the near-emitter 40 positioned below the sheath 104. The plated conductor below the sheath 104 may extend around the outer diameter of the elongated body 22 as near the near-emitter 40, or may be narrowly shaped like a plated lead. Figure 10 The proximal lead 108 is shown to be connected to the outer surface of the near-emitter 40 and disposed between the sheath 104 and the elongated body 22. The second electrical path 78 and the sheath 104 may extend proximally along the entire length of the elongated body 22 or a portion thereof. In one example, the second electrical path 78 and the sheath 104 may extend proximally until they are positioned at the hub 23 connected to the proximal portion of the elongated body 22 (see [link to previous section]). Figure 11 Below ).

[0048] Because the elongated body 22 is made of polymer, it can be relatively radiolucent in fluorescence fluoroscopy and other X-ray imaging. The electrode assembly 12 of this disclosure includes at least one radiopaque marker 106 with sufficient radiometric density to be visualized on X-ray imaging. The radiopaque marker 106 can be attached at any suitable location along the elongated body 22. In exemplary embodiments and referenced... Figure 9 and 10The radiopaque marker 106 is a strip attached to the near emitter 40. Furthermore, the radiopaque marker 106 can be positioned precisely on the distal side of the sheath 104 to make the near emitter 40 visible on X-ray imaging. The radiopaque marker 106 can be formed of a metal such as platinum or platinum-iridium for easy visibility on X-ray imaging. The radiopaque marker 106 can form part of the second electrical path 78. For example, Figure 9 A non-transmissive marker 106 connected to the near emitter 40 is shown, and Figure 10 The radiopaque marker 106 is a strip that secures the near-side lead 108 to the near-emitter 40. The radiopaque marker 106 may be crimped, forged, or otherwise secured to the near-emitter 40 or the elongated body 22.

[0049] As previously described, the distal cap 46 is formed of a conductive material. Therefore, the distal cap 46 can be readily visualized on X-ray imaging to visually display the distal emitter 38. The elongated body 22 can be relatively radiopaque, and the distal cap 46 and the radiopaque marker 106 can be particularly visible on X-ray imaging to facilitate accurate positioning within the anatomical location of interest. It is readily understood that the distal cap 46 thus provides several functions associated with the electrode assembly 12. In some embodiments, another radiopaque marker (not shown) can be a swaged band near the distal end 20 of the electrode assembly 12. This arrangement may be particularly suitable if the distal cap 46 is an adhesive or formed of another material that is not sufficiently radiopaque. Additionally or alternatively, the near and far emitters 38, 40 formed of plated metal can themselves be radiopaque. For example, a sufficiently thick layer plated with a high atomic weight metal (e.g., platinum) can provide sufficient radio density for visualization on X-ray imaging. Furthermore, it is envisioned that the radiopaque marker 106 does not need to be disposed on or attached to the outer surface 72 of the elongated body 22. In some embodiments, the radiopaque marker 106 may be disposed within the cavities 34, 35. For example, a segment of wire, such as a tungsten filament, may be fixed at one or more desired locations within the cavities 34, 35.

[0050] The electrode assembly 12 of this disclosure facilitates the treatment of tissue in anatomical locations previously inaccessible with conventional devices. More specifically, the flexibility of the elongated body 22 provides access to anatomical locations requiring greater curvature and / or sharper radii of curvature. (Refer to now) Figure 11The elongated body 22 is configured to bend or flex when deployed through the introducer assembly 13. A suitable introducer assembly is disclosed in co-owned U.S. Patent No. 9,839,443, issued December 12, 2017, the entire contents of which are incorporated herein by reference. In some embodiments, the elongated body 22 is flexible enough to be deployed to bend through curves of at least 60 degrees, more specifically at least 90 degrees, and even more specifically at least 120 degrees. Furthermore, the elongated body 22 is flexible enough to be deployed through curves with radii of curvature ranging from approximately 0.75 to 2.50 inches, more specifically from approximately 1.25 to 2.25 inches.

[0051] The ablation system 11 may include an electrode assembly 12, a guide assembly 13, and an access cannula 14. The ablation system 11 may be packaged as a kit. An exemplary manner in which the ablation system 11 can be deployed is the ablation of a bone tumor (BT) within a vertebral body. The bone tumor is displayed significantly posterior and significantly contralateral to the pedicle, and the access cannula 14 is deployed through the pedicle. The electrode assembly 12 is deployed to curve approximately 180 degrees to access the bone tumor. Another exemplary manner in which the ablation system 11 can be deployed is the ablation of the basal vergeon nerve (BVN) within a vertebral body. It is well known that, to obtain optical results, the principal posterior portion of the basal vergeon nerve should be ablated. To access the principal posterior portion of the basal vergeon nerve, the electrode assembly 12 is shown deployed through a curve of approximately 270 degrees. Alternatively, the electrode assembly 12 may be deployed through a sharper curve to access the principal posterior portion of the basal vergeon nerve.

[0052] Access cannula 14 is deployed through the vertebral pedicle, and guide assembly 13 can be deployed through access cannula 14. Guide assembly 13 may include sheath 15 configured to be positioned in a curved configuration within the vertebral body, outside access cannula 14. Electrode assembly 12 is configured to follow the curved configuration of sheath 15 or the curved path created by guide assembly 13 within the bone. Distal end 20 of electrode assembly 12 may be positioned approximately flush with the distal end of sheath 15. The positioning of electrode assembly 12 can be confirmed on X-ray imaging by visualizing distal cap 46 and radiopaque marker 106. Sheath 15 may be retracted to expose proximal and distal emitters 38, 40 of electrode assemblies 12, 12', for example, within a bone tumor or across the basal spinal nerve. Electrode assemblies 12, 12' are manipulated to ablate bone tumors or the basal spinal nerve. It should be understood that the ablation system 11 of this disclosure can be used in any suitable anatomical location, including bone and non-bone applications. Exemplary non-bone applications include facet rhizotomy, sacroiliac nerve block, genicular nerve block, etc.

[0053] The foregoing disclosure is not intended to be exhaustive or to limit the invention to any particular form. The terminology used is intended to be descriptive rather than restrictive. In view of the foregoing teachings, many modifications and variations are possible, and the invention may be practiced in ways other than those specifically described. For example, it should be understood that the inner diameter of the first cavity 34 (and / or the second cavity 35) is... Figure 4-10 The image may not be shown to scale and has been exaggerated for clarity of the components of electrode assembly 12. In other words, thermocouple 62, thiopanle 90, and / or distal lead 92 can be arranged in a relatively form-fitting manner within the first cavity 34. Additional media, such as dielectric material, may be provided to block any free space within the first cavity 34.

Claims

1. An electrode assembly, comprising: An elongated body includes an outer surface opposite to an inner surface defining a first inner cavity, a second inner cavity fluidly separated from the first inner cavity, and a discharge port fluidly communicating with the first inner cavity, wherein the elongated body is formed of a flexible, non-conductive material; The near emitter is formed by plating a first metal onto a first portion of the outer surface; and A remote transmitter is formed by plating a second metal onto a second portion of the outer surface, wherein the first metal and the second metal are the same or different materials; A distal lead extending through the second inner cavity and electrically connected to the remote transmitter; and The lead extends through the first cavity and connects to the proximal lead of the near-emitter via the discharge port. The first portion and the second portion are spaced apart from each other, such that the elongated body forms an insulating spacer between the near emitter and the far emitter.

2. The electrode assembly of claim 1, further comprising a distal cap attached to the elongated body to define a distal end of the electrode assembly, wherein the distal cap is formed of a conductive material and arranged to be electrically connected to the distal transmitter.

3. The electrode assembly according to claim 2, wherein, The distal cap is fastened to the distal surface of the elongated body, and the distal emitter is formed by electrodepositing the second metal on the distal surface.

4. The electrode assembly according to claim 2, wherein, The distal cap is at least partially secured within the first inner cavity, and the distal emitter is formed by electrodepositing the second metal onto the inner surface.

5. The electrode assembly of claim 2, further comprising a thermocouple extending through the second inner cavity and in thermal communication with the distal cap.

6. The electrode assembly of claim 1, further comprising a sheath coaxially disposed on a portion of the near-emitter, wherein the sheath is formed of a non-conductive material.

7. The electrode assembly of claim 1, further comprising a radiopaque marker attached to the near emitter.

8. The electrode assembly according to claim 1, wherein, The emission port is axially positioned within the near-emitter.

9. The electrode assembly according to claim 1, wherein, The discharge port is axially positioned within the insulating space.

10. The electrode assembly according to claim 2, wherein, The distal cap is solder.

11. The electrode assembly according to claim 1, wherein, The near emitter and the far emitter are formed by a combination of the following: electroless plating, electrodeposition, immersion, physical vapor deposition, chemical vapor deposition and plasma spraying.

12. The electrode assembly according to claim 1, wherein, The slender body is a one-piece structure.

13. An electrode assembly, comprising: An elongated body includes an outer surface opposite to an inner surface defining a first inner cavity, a second inner cavity fluidly separated from the first inner cavity, and a discharge port fluidly communicating with the first inner cavity, wherein the elongated body is formed of a flexible, non-conductive material; A near emitter formed by plating a first metal onto a first portion of the outer surface; and A far-field emitter formed by plating a second metal on a second portion of the outer surface, wherein the first portion and the second portion are spaced apart from each other such that the elongated body forms an insulating space between the near-field emitter and the far-field emitter, and the first metal and the second metal are the same or different materials; Extending through the first inner cavity and connected to the proximal lead of the near emitter via the discharge port; and A distal cap is attached to the elongated body to define the distal end of the electrode assembly, wherein the distal cap is formed of a conductive material and arranged to be electrically connected to the distal transmitter.

14. The electrode assembly according to claim 13, wherein, The distal cap is fastened to the distal surface of the elongated body, and the distal emitter is formed by electrodepositing the second metal on the distal surface.

15. The electrode assembly according to claim 13, wherein, The distal cap is at least partially secured within the first inner cavity, and the distal emitter is formed by electrodepositing the second metal onto the inner surface.

16. The electrode assembly of claim 13, further comprising a thermocouple extending through the second inner cavity and in thermal communication with the distal cap.

17. The electrode assembly of claim 16, wherein, The second inner cavity is defined by a thiopant tube that extends through the first inner cavity and includes a closed distal end connected to the distal cap, wherein the thermocouple is disposed within the thiopant tube.

18. The electrode assembly of claim 17, further comprising a shield providing electrical insulation between the thermocouple and the thiopanle.

19. The electrode assembly of claim 13, further comprising a sheath coaxially disposed on a portion of the near-emitter, wherein the sheath is formed of a non-conductive material.

20. The electrode assembly of claim 19, further comprising a proximal lead arranged in electrical communication with the proximal emitter and extending proximally between the outer surfaces of the sheath and the elongated body.

21. The electrode assembly of claim 20, further comprising a nontransmissive marking tape securing the proximal lead to the proximal emitter.

22. The electrode assembly of claim 13, further comprising a radiopaque marker attached to the near emitter.

23. The electrode assembly according to claim 13, wherein, The emission port is axially positioned within the near-emitter.

24. The electrode assembly according to claim 13, wherein, The discharge port is axially positioned within the insulating space.

25. The electrode assembly according to claim 13, wherein, The distal cap is solder.

26. The electrode assembly according to claim 13, wherein, The first metal and the second metal are selected from the group consisting of gold, platinum, copper, nickel, stainless steel, titanium and chromium.

27. The electrode assembly according to claim 13, wherein, The near emitter and the far emitter are formed by a combination of the following: electroless plating, electrodeposition, immersion, physical vapor deposition, chemical vapor deposition and plasma spraying.

28. The electrode assembly according to claim 13, wherein, The slender body is a one-piece structure.

29. An electrode assembly, comprising: An elongated body includes an outer surface opposite to an inner surface defining a first inner cavity, a second inner cavity fluidly separated from the first inner cavity, and a discharge port fluidly communicating with the first inner cavity, wherein the elongated body is formed of a flexible, non-conductive material; A near emitter formed by plating a first metal onto a first portion of the outer surface; and A far emitter formed by plating a second metal on a second portion of the outer surface, wherein the first portion and the second portion are spaced apart from each other such that the elongated body forms an insulating space between the near emitter and the far emitter, wherein the first metal and the second metal are the same or different materials; A proximal lead extending through the first inner cavity and connected to the near-emitter via the discharge port; and A sheath coaxially disposed on a portion of the near-emitter, wherein the sheath is formed of a non-conductive material.

30. The electrode assembly of claim 29, further comprising a radiopaque marker attached to the near emitter.

31. The electrode assembly according to claim 29, wherein, The emission port is axially positioned within the near-emitter.

32. The electrode assembly according to claim 29, wherein, The discharge port is axially positioned within the insulating space.

33. The electrode assembly of claim 29, further comprising a distal cap attached to the elongated body to define a distal end of the electrode assembly, wherein the distal cap is formed of a conductive material and arranged to be electrically connected to the distal transmitter, the distal cap being solder.

34. The electrode assembly according to claim 29, wherein, The first metal and the second metal are selected from the group consisting of gold, platinum, copper, nickel, stainless steel, titanium and chromium.

35. The electrode assembly according to claim 29, wherein, The near emitter and the far emitter are formed by a combination of the following: electroless plating, electrodeposition, immersion, physical vapor deposition, chemical vapor deposition and plasma spraying.

36. The electrode assembly according to claim 29, wherein, The slender body is a one-piece structure.

37. An electrode assembly, comprising: An elongated body includes an outer surface opposite to an inner surface defining a first inner cavity, a second inner cavity fluidly separated from the first inner cavity, and a discharge port fluidly communicating with the first inner cavity, wherein the elongated body is formed of a flexible, non-conductive material; A near emitter formed by plating a first metal onto a first portion of the outer surface; and A far emitter formed by plating a second metal on a second portion of the outer surface, wherein the first portion and the second portion are spaced apart from each other such that the elongated body forms an insulating space between the near emitter and the far emitter, wherein the first metal and the second metal are the same or different materials; A sheath coaxially disposed on a portion of the near-emitter, wherein the sheath is formed of a non-conductive material; A proximal lead is arranged to be electrically connected to the proximal emitter and extends proximally between the outer surfaces of the sheath and the elongated body, wherein the first cavity extends longitudinally within a portion of the elongated body and radially outward to the discharge port, and the proximal lead is disposed within the first cavity. and Secure the proximal lead to the non-transmissive marking tape of the near emitter.

38. The electrode assembly according to claim 37, wherein, The emission port is axially positioned within the near-emitter.

39. The electrode assembly according to claim 37, wherein, The discharge port is axially positioned within the insulating space.

40. The electrode assembly of claim 37, further comprising a distal cap attached to the elongated body to define a distal end of the electrode assembly, wherein the distal cap is formed of a conductive material and arranged to be electrically connected to the distal transmitter, the distal cap being solder.

41. The electrode assembly according to claim 37, wherein, The first metal and the second metal are selected from the group consisting of gold, platinum, copper, nickel, stainless steel, titanium and chromium.

42. The electrode assembly according to claim 37, wherein, The near emitter and the far emitter are formed by a combination of the following: electroless plating, electrodeposition, immersion, physical vapor deposition, chemical vapor deposition and plasma spraying.

43. The electrode assembly of claim 37, wherein, The slender body is a one-piece structure.

44. An electrode assembly, comprising: An elongated body includes an outer surface opposite to an inner surface defining a first inner cavity, a second inner cavity fluidly separated from the first inner cavity, and a discharge port fluidly communicating with the first inner cavity, wherein the elongated body is formed of a flexible, non-conductive material; A near emitter formed by plating a first metal onto a first portion of the outer surface; A far emitter formed by plating a second metal on a second portion of the outer surface, wherein the first portion and the second portion are spaced apart from each other such that the elongated body forms an insulating space between the near emitter and the far emitter, wherein the first metal and the second metal are the same or different materials; Wherein, the second inner cavity defines an electrical passage for an electrical component of the electrode assembly, and the first inner cavity defines a fluid passage for discharging fluid received from a fluid source through the discharge port, wherein the first inner cavity extends longitudinally within a portion of the elongated body and radially outward to the discharge port; and A proximal lead is arranged to be electrically connected to the near-emitter and disposed within the first inner cavity.

45. The electrode assembly of claim 44, wherein, The first metal and the second metal are selected from the group consisting of gold, platinum, copper, nickel, stainless steel, titanium and chromium.

46. ​​The electrode assembly of claim 44, wherein, The near emitter and the far emitter are formed by a combination of the following: electroless plating, electrodeposition, immersion, physical vapor deposition, chemical vapor deposition and plasma spraying.

47. The electrode assembly of claim 44, wherein, The slender body is a one-piece structure.

48. The electrode assembly of claim 47, wherein, The elongated body is an extruded section of polyetheretherketone.

49. An ablation system, comprising: Electrode assembly according to any one of claims 1-48; and Micro-infusion module.

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