Ablation electrode assemblies comprising enhanced position sensing capabilities

Abstract

To provide electrode assemblies.SOLUTION: The disclosed technology includes an electrode assembly comprising an electrode body comprising a top surface and a bottom surface. The electrode body can be configured to deliver ablative energy to tissue through at least the top surface. The electrode assembly can further include a coil disposed near the bottom surface. The coil can be configured to generate a voltage when subject to a magnetic field. The electrode assembly can include: a member that is disposed near the coil and comprises a high-magnetic-permeability material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the priority and benefit of U.S. Provisional Patent Application No. 63 / 611,547, filed on December 18, 2023 (Attorney Docket No.: BIO6838USPSP1 - 253757.000387), under 35 U.S.C. § 119(e), the entire content of which is incorporated herein by reference.

[0002] (Field of the Invention) The present invention generally relates to ablation electrode assemblies, and more specifically to ablation electrode assemblies comprising electromagnetic coils and high - permeability materials that provide magnetic - based position sensing.

Background Art

[0003] Intravascular catheters are commonly used to map or ablate myocardial tissue. An intravascular catheter typically includes an end - effector having one or more electrodes configured to receive electrical signals from tissue for mapping and / or deliver ablation energy to tissue ablation. To ensure that the electrodes are accurately positioned for mapping or ablation, some end - effectors include position sensing such as electromagnetic position sensing or active current location (ACL) technology.

[0004] Electromagnetic position sensing typically utilizes an electromagnetic coil disposed on or near the end - effector that is configured to generate a current when exposed to a magnetic field induced by a magnetic - field generator positioned external to the patient. However, many electromagnetic sensors require a coil with multiple windings to ensure that the electromagnetic sensor has sufficient sensitivity to detect the electromagnetic field. Unfortunately, increasing the number of windings increases the size of the electromagnetic sensor. As is understood, the end - effector desirably is small enough for cardiovascular procedures.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, in the art, there is a need for a method to improve the sensitivity of electromagnetic sensors while reducing the size of the end effector. The technology disclosed herein addresses these problems.

Means for Solving the Problems

[0006] According to an embodiment of the present invention, an electrode assembly is provided that includes an electrode body having a top surface and a bottom surface. The electrode body can be configured to deliver ablation energy to tissue through at least the top surface. The electrode assembly can further include a coil disposed near the bottom surface. The coil can be configured to generate a voltage when exposed to a magnetic field. The electrode assembly can include a member disposed near the coil and including a high magnetic permeability material.

[0007] The technology of the present disclosure can include a medical device comprising a flexible shaft extending along a longitudinal axis and a plurality of spines disposed at a distal end of the flexible shaft. The plurality of spines can be configured to bend radially outward from the longitudinal axis and transition between an expanded configuration and a collapsed configuration. The medical device can further include a plurality of electrode assemblies attached to the plurality of spines. Each electrode assembly of the plurality of electrode assemblies can include an electrode body having a top surface and a bottom surface. The electrode body can be configured to deliver ablation energy to tissue through at least the top surface. The electrode assembly can include a coil disposed near the bottom surface. The coil can be configured to generate a voltage when exposed to a magnetic field. The electrode assembly can include a member disposed near the coil and including a high magnetic permeability material.

[0008] Additional features, functions, and applications of the technology of the present disclosure are discussed in more detail herein.

Brief Description of the Drawings

[0009]

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[0010] The technology of the present disclosure includes a plurality of electrode assemblies coupled to a plurality of spines forming a basket catheter disposed at a distal end of a flexible shaft. Each electrode assembly can include an electrode body designed to deliver ablation energy to tissue. Each electrode assembly can further include an electromagnetic coil attached to the electrode body, and the electromagnetic coil is configured to generate an electric current when exposed to an electromagnetic field generated by an electromagnetic field generator. The real-time position of the distal end of the catheter can be tracked based on the current generated in the electromagnetic coil. By disposing the electromagnetic coil on the electrode body, the overall size of the end effector can be reduced, and a plurality of electromagnetic coils can be utilized (for a catheter having a plurality of electrode assemblies) to enhance the accuracy of position sensing. To further enhance the sensitivity of the electromagnetic coil, the electrode assembly can further include a high-permeability material disposed near the electromagnetic coil.

[0011] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. The drawings are not necessarily to scale, depict selected embodiments, and are not intended to limit the scope of the invention. The detailed description is by way of example and not limitation, and illustrates the principles of the invention. This description enables those skilled in the art to make and use the invention and describes some embodiments, adaptations, variations, alternatives, and uses of the invention, including what is presently considered to be the best mode of carrying out the invention.

[0012] As used herein, the term "about" or "substantially" with respect to any numerical value or range indicates a reasonable dimensional tolerance that allows a component or collection to function for the intended purpose described herein. More specifically, "about" or "substantially" can refer to a range of values that are ±20% of the recited value. For example, "about 90%" can refer to a range of values from 71% to 110%. Additionally, as used herein, the terms "patient", "host", "user", and "subject" refer to any human or animal subject, and the use of the present invention in human patients represents a preferred embodiment, but is not intended to limit the system or method to human use. Similarly, the term "proximal" indicates a position closer to the operator or physician, while "distal" indicates a position farther from the operator or physician.

[0013] As discussed herein, the vasculature of "patient", "host", "user", and "subject" can be that of a human or any animal. It should be understood that the animal can be of various arbitrary applicable types including, but not limited to, mammals, veterinary animals, livestock animals, or pet animals. As an example, the animal can be a laboratory animal (e.g., rat, dog, pig, monkey, etc.) specifically selected to have certain properties similar to humans. It should be understood that the subject can be, for example, any applicable human patient.

[0014] As discussed herein, "physician" can include a doctor, surgeon, technician, scientist, operator, or any other individual or delivery instrument related to the delivery of a multi-electrode catheter for the treatment of drug-refractory atrial fibrillation to a subject.

[0015] As discussed herein, the terms "ablating" or "ablation," when referring to the devices and corresponding systems of the present disclosure, refer throughout the present disclosure to non-thermal energies such as reversible electroporation or irreversible electroporation (IRE), which are interchangeably referred to as pulsed electric field (PEF) and pulsed field ablation (PFA), or thermal energies such as radiofrequency (RF) ablation or cryoablation, and to components and structural features configured to reduce or prevent the generation of irregular cardiac signals within cells. When referring to the devices and corresponding systems of the present disclosure, ablating or ablation is used throughout the present disclosure with reference to thermal or non-thermal ablation of cardiac tissue for certain conditions including, but not limited to, arrhythmias, atrial fibrillation ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The terms "ablating" or "ablation" also include known methods, devices, and systems for achieving various forms of body tissue ablation, as understood by those of skill in the art.

[0016] As discussed herein, the terms "tubular" and "tube" are to be construed broadly and are not limited to a straight cylindrical structure, or a structure with a cross-section that is strictly circular, or a structure with a uniform cross-section throughout its length. For example, a tubular structure is generally shown as a substantially straight cylindrical structure. However, a tubular structure may have a tapered or curved outer or inner surface without departing from the scope of the present disclosure.

[0017] Refer to FIG. 1, which shows an exemplary catheter-based electrophysiology mapping and ablation system 10. System 10 includes a plurality of catheters that are percutaneously inserted by a physician 24 through the vasculature of a patient 23 into a chamber or vascular structure of the heart 12. Typically, a delivery sheath catheter is inserted into the left atrium or right atrium near a desired location in the heart 12. Thereafter, a plurality of catheters can be inserted into the delivery sheath catheter to reach the desired location. The plurality of catheters can include catheters dedicated to sensing intracardiac electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. To sense the IEGM, the physician 24 contacts the distal tip 28 of the catheter 14 with the heart wall to sense the target site of the heart 12. The end effector of the mapping catheter may include a basket catheter, a planar catheter, a focus catheter, a balloon catheter, etc. For ablation, the physician 24 similarly moves the distal end of the ablation catheter to the target site for ablation (as shown in the inset of FIG. 1). Similarly, the end effector of the ablation catheter may include a basket catheter, a planar catheter, a focus catheter, a balloon catheter, etc.

[0018] Catheter 14 is an exemplary catheter that includes one, preferably a plurality of electrode assemblies 26 that are optionally distributed across a plurality of spines 22 at the distal tip 28 and configured to deliver ablation energy to tissue. Catheter 14 may additionally include a position sensor 29 embedded within or near the distal tip 28 to track the position and orientation of the distal tip 28. Optionally and preferably, the position sensor 29 is a magnetic-based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0019] The magnetic-based position sensor 29 can operate with a position pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field within a predetermined working volume. The real-time position of the distal tip 28 of the catheter 14 can be tracked based on the magnetic field generated by the position pad 25 and sensed by the magnetic-based position sensor 29. Details of magnetic-based position sensing techniques are described in U.S. Patent Nos. 5,391,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, 6,892,091, and the entireties of each of these are hereby incorporated by reference as if fully set forth herein.

[0020] The system 10 includes one or more electrode patches 38 positioned for skin contact on the patient 23 to establish position referencing of the position pad 25 and impedance-based tracking of the electrode assembly 26. For impedance-based tracking, current is directed to the electrode assembly 26 and sensed at the electrode skin patches 38, whereby the position of each electrode can be triangulated via the electrode patches 38. Details of impedance-based position tracking techniques are described in U.S. Patent Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, and the entireties of each of these are hereby incorporated by reference as if fully set forth herein.

[0021] The recorder 11 displays an electrogram 21 captured by the body surface ECG electrodes 18 and an intracardiac electrogram (IEGM) captured by the electrode assembly 26 of the catheter 14. The recorder 11 may include pacing capabilities for pacing the rhythm of the heart and / or may be electrically connected to an independent pacemaker.

[0022] System 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more of the electrodes at the distal tip of a catheter configured to ablate. The energy generated by ablation energy generator 50 may include high-frequency (RF) energy, pulsed-field ablation (PFA) energy, or a combination thereof, including unipolar or bipolar high-voltage DC pulses such that the energy can be used to perform irreversible electroporation (IRE), but is not limited thereto.

[0023] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheter, the electrophysiology equipment, the power supply, and a workstation 55 that controls the operation of system 10. The electrophysiology equipment of system 10 may include, for example, a plurality of catheters, position pads 25, body surface ECG electrodes 18, electrode patches 38, ablation energy generator 50, and recorder 11. Optionally and preferably, PIU 30 additionally includes processing capabilities for performing real-time calculations of the position of the catheter and for performing ECG calculations.

[0024] The workstation 55 includes a memory, a processor unit having a memory or storage device loaded with appropriate operating software, and user interface capabilities. The workstation 55 optionally provides a plurality of functions including: (1) modeling the endocardial anatomical structure in three dimensions (3D) and rendering it to display a model or anatomical map 20 on a display device 27; (2) displaying on the display device 27 a representative visual display or image of an activation sequence (or other data) compiled from the recorded electrogram 21 superimposed on the rendered anatomical map 20; (3) displaying the real-time positions and orientations of a plurality of catheters within the heart chamber; and (4) displaying on the display device 27 regions of interest such as locations where ablation energy is being applied. One commercially available product embodying the elements of the system 10 is available as the CARTO (trademark) 3 system, marketed by Biosense Webster, Inc. (31 Technology Drive, Suite 200, Irvine, CA 92618, USA).

[0025] FIG. 2A is a schematic drawing showing a perspective view of a medical probe 200 having an end effector with a distal tip 28 that is a basket assembly in an expanded configuration when not constrained, such as by being advanced from the tubular shaft lumen 80 at the distal end 85 of the tubular shaft (depicted in FIG. 2B). FIG. 2B shows the basket assembly in a collapsed configuration within the tubular shaft 82. In the expanded configuration (FIG. 2A), the spine 22 deflects radially outward along the longitudinal axis 86, and in the collapsed configuration (FIG. 2B), the spine is constrained generally along the longitudinal axis 86 of the tubular shaft 82 by the inner wall of the tubular shaft 82.

[0026] As shown in FIG. 2A, the basket assembly 28 (also referred to interchangeably herein as the “distal tip”) is formed at the end of the flexible shaft 84 and includes a plurality of flexible spines 22 connected at both ends. During a medical procedure, the physician 24 can deploy the basket assembly 28 by extending the flexible shaft 84 from the tubular shaft 82, moving the basket assembly 28 out of the tubular shaft 82 and transitioning it to an expanded configuration. The spines 22 can have an elliptical (e.g., circular) or rectangular (which may appear flat) cross-section and can include a flexible elastic material (e.g., a shape memory alloy such as nickel-titanium, also known as nitinol) that forms struts, as described in more detail herein.

[0027] In the embodiments described herein, the electrode assembly 26 can be configured to deliver ablation energy (RF and / or IRE) to tissue within the heart 12 or other portions of the patient 23's body. In addition to using the electrode assembly 26 to deliver ablation energy, the electrode assembly can also be used to measure physiological properties such as local surface potentials (e.g., IEGM signals) at each location on the tissue within the heart 12. The electrode assembly 26 can be biased such that a larger surface area of the electrode body of the electrode assembly 26 faces outwardly from the basket assembly 28, whereby the electrode assembly 26 delivers a greater amount of electrical energy outwardly (i.e., toward the tissue of the heart 12) away from the basket assembly 28 rather than inwardly toward the longitudinal axis 86 of the basket assembly 28.

[0028] The basket assembly 28 can include a stem 96 that extends longitudinally from the distal end 90 of the flexible shaft 84 toward the distal end 212 of the basket assembly 28. The techniques of the present disclosure can include an irrigation system that delivers irrigation fluid to the spray ports 98. For example, the stem 96 can include a plurality of spray ports 98, and each given spray port 98 can be angled to direct delivery of the irrigation fluid to either a given electrode 26 or tissue within the heart 12. The electrode assembly 26 can be cooled by directing irrigation fluid thereto via the spray ports 98 to a portion of the electrode assembly 26 inside the spine 22. The basket assembly 28 can include a central intersection portion 211 at a point where the spine 22 converges near the distal end 212.

[0029] Referring to FIGS. 3A and 3B, the electrode assembly 26 can have an electrode body 330 having a top surface 332 and a bottom surface 334. The top surface 332 can be configured to face outwardly from the basket assembly 28 and contact tissue, and the bottom surface 334 can be configured to face inwardly toward the longitudinal axis 86 of the basket assembly 28 such that the bottom surface 334 is less likely to contact tissue. The electrode body 330 can be configured to deliver ablation energy to tissue, at least through the top surface 332. The top surface 332 of the electrode body 330 can be substantially flat or planar. Alternatively, the top surface 332 can be rounded or have a contoured outer shape. The bottom surface 334 of the electrode body 330 can be substantially flat or planar. In some embodiments, the flat portion of the bottom surface 334 can include a larger surface area compared to the flat portion of the top surface 332.

[0030] The electrode body 330 can include a lumen 336 that extends through the electrode body 330. The lumen 336 can be configured to receive the spine 22 of an end effector, such as the spine 22 of the basket assembly 28, as depicted in FIG. 2A. The spine 22 can be provided along the longitudinal axis L-L of the lumen 336. The electrode assembly 26 can be fixed to the spine 22 of the basket assembly 28. Fixing the electrode assembly 26 to the spine 22 can include a coupling between the spine 22 and the inner surface of the lumen 336. For example, the electrode assembly 26 can be crimped, adhered, fastened, or otherwise coupled to the spine 22 to prevent the electrode assembly 26 from sliding along the length of the spine 22.

[0031] Referring to FIGS. 4A-4C, the electrode assembly 26 can include an electrode body 330, a coil 440 disposed near the bottom surface 334 of the electrode body 330, and a member 450 disposed near the bottom surface 334 of the electrode body 330. The electrode body 330 can be configured to deliver ablation energy to tissue through the upper surface 332. The member 450 can include a high permeability material. The coil 440 can be configured to generate a current when exposed to a magnetic field. In some embodiments, the coil 440 can include a single axis sensor (SAS) or a triple axis sensor (TAS). The coil 400 can include a conductive material wound in a coil and disposed on the bottom surface 334, or a coil formed within a flexible circuit that can be attached to the bottom surface 334. The coil 440 can include a conductive wire 442 for conducting the current induced on the coil 440 to the patient interface unit 30. As will be appreciated, attaching the coil 440 to the electrode body 330 enables the position of each individual electrode of the basket assembly 28 (or each of the electrode assemblies 26 including at least the coil 440) to be detected. In this way, the physician 24 can more accurately determine the position of the electrode assembly 26 before applying ablation energy to the tissue.

[0032] The member 450 can be a high-permeability material provided near the coil 440 to help increase the sensitivity of the coil 440. For example, when the coil 440 includes a uniaxial sensor, the member 450 can help strengthen the electromagnetic field near the uniaxial coil. The high-permeability material can include mu-metal, nanocrystalline metal, 99.95% pure iron, or combinations thereof. The member 450 can have a relative permeability of, for example, about 50,000 to about 200,000. By disposing the member 450 near the coil 440, the member 450 provides a path for the magnetic field passing through the member 450 to reach the coil 440, helping to increase the influence of the magnetic field on the coil 440, thereby increasing the sensitivity of the coil 440 in the magnetic field. The high-permeability characteristic of the member 450 provides a low-reluctance path for the magnetic flux. In this way, the technology of the present disclosure can increase the magnetic field near the coil 440, thereby helping to induce a current on the coil 440 used for magnetic-based position sensing.

[0033] Referring to FIG. 4A, the electrode assembly 26 can include an electrode body 330 having a bottom surface 334. The electrode assembly 26 can include a coil 440 disposed near the bottom surface 334 of the electrode body 330. The electrode assembly 26 can include a member 450 disposed near the bottom surface 334 of the electrode body 330. In some embodiments, the member 450 can be disposed on the bottom surface 334 of the electrode body 330, and the coil 440 can be disposed on the bottom surface of the member 450. Alternatively, the coil 440 can be disposed on the bottom surface 334 of the electrode body 330, and the member 450 can be disposed on the bottom surface of the coil 440.

[0034] Figure 4B depicts a cross-sectional view of the electrode assembly 26 along line A-A shown in Figure 4A. The electrode assembly 26 can include an electrode body 330 having a top surface 332, a bottom surface 334, and a lumen 336 provided through the electrode body 330. As shown, the electrode assembly 26 can include a member 450 disposed on the bottom surface 334 of the electrode body 330, which is a high-permeability material. The coil 440 can be disposed on the bottom side of the member 450 such that the member 450 is provided between the bottom surface 334 of the electrode body 330 and the coil 440.

[0035] Referring to Figure 4C, in another embodiment of the technology of the present disclosure, the coil 440 can be disposed on the bottom surface 334 of the electrode body 330. Further, the member 450 can be disposed on the bottom surface of the coil 440 such that the coil 440 is provided between the bottom surface 334 of the electrode body 330 and the member 450.

[0036] Figures 4D and 4E show cross-sectional views of the electrode assembly 26 including an insulating material 460 disposed on the bottom surface 334 of the electrode body 330. The insulating material 460 is disposed on the bottom surface 334 of the electrode body 330 to form an insulating layer on the bottom surface 334 of the electrode body 330 and can electrically insulate the electrode body 330 from the coil 440 and the member 450. In this way, the insulating material 460 can prevent interference between the coil 440 and the electrode during ablation and / or positioning operations.

[0037] Referring to Figure 4D, the insulating material 460 can be disposed between the coil 440 and the bottom surface 334 of the electrode body 330. The member 450 can be disposed under the coil 440 such that the coil 440 is disposed between the insulating material 460 and the member 450. On the other hand, Figure 4E depicts the insulating material 460 disposed between the member 450 and the bottom surface 334 of the electrode body 330. The coil 440 can be disposed under the member 450 such that the member 450 is disposed between the insulating material 460 and the coil 440.

[0038] Figure 4F depicts a cross-sectional view of an electrode assembly 26 including a member 450 disposed within an electrode body 330. The electrode body 330 can be configured to deliver ablation energy to tissue through an upper surface 332. The member 450 can include a high magnetic permeability material that is at least partially disposed within the electrode body 330. The member 450 can be disposed within the electrode body 330 near a bottom surface 334 of the electrode body 330, and the coil 440 can be disposed on the bottom surface 334 of the electrode body 330. In this way, the member 450 can be disposed near the coil 440 and can help enhance the sensitivity of the coil 440 when exposed to a magnetic field as described herein.

[0039] Figures 5A-5F depict variations of an electrode body that can be used with the techniques of the present disclosure. That is, the features described above herein can be applicable to a variety of other electrode body configurations including, but not limited to, the electrode bodies shown in Figures 5A-5F. Further, each of the electrodes depicted in Figures 5A-5F includes lumens 336A, 336B, 336C configured to receive a spine (e.g., spine 22) for attaching the electrode bodies 330A, 330B, 330C to the spine, although it will be understood that other types of attachment mechanisms are contemplated. For example, the techniques of the present disclosure can include electrode assemblies that are attached to a spine by crimping, fastening, adhesion, or the like. Instead of inserting a spine through the lumens 336A, 336B, 336C, the electrode assembly is attached to the spine.

[0040] Figures 5A and 5B depict a variant of the electrode body 330A comprising a top surface 332A, a bottom surface 334A, and a lumen 336A configured to deliver ablation energy to tissue through at least the top surface 332A of the electrode body 330A. Referring to Figures 5A and 5B, the electrode body 330A can be curved such that the top surface 332A includes a convex curvature and the bottom surface 334A includes a convex curvature. This configuration can enable an increase in the surface area at the top surface 332A where ablation energy is applied to the tissue as compared to the bottom surface 334A. The electrode body 330A can include a lumen 336A configured to receive a spine of a basket catheter along the longitudinal axis L-L of the electrode body 330A through the electrode body. The electrode body 330A can further comprise a recess 338A for accommodating wiring that provides electricity for ablation. The recess 338A can be formed by an extension of the lumen 336A.

[0041] Figures 5C and 5D depict a variant of the electrode body 330B comprising a top surface 332B, a bottom surface 334B, and a lumen 336B configured to deliver ablation energy to tissue through at least the top surface 332B of the electrode body 330B. Referring to Figures 5C and 5D, the electrode body 330B can be an elongated body including a substantially elliptical shape. The top surface 332B and the bottom surface 334B can be substantially flat. The electrode body 330B can include a lumen 336B configured to receive a spine of a basket catheter along the longitudinal axis L-L of the electrode body 330B through the electrode body. The electrode body 330B can further comprise a recess 338B for accommodating wiring that provides electricity for ablation. The recess 338B can be formed by an extension of the lumen 336B.

[0042] Figures 5E and 5F depict a variant of the electrode body 330C comprising a top surface 332C, a bottom surface 334C, and a lumen 336C configured to deliver ablation energy to tissue through at least the top surface 332C of the electrode body 330C. Referring to FIGS. 5C and 5D, the electrode body 330C can comprise a top surface 332C having a convex curvature. The electrode body 330C can be tapered from the top surface 332C towards the bottom surface 334C. This configuration can enable an increase in the surface area at the top surface 332C where ablation energy is applied to the tissue, as compared to the bottom surface 334C. The electrode body 330C can include a lumen 336C configured to receive the spine of the basket catheter along the longitudinal axis L-L of the electrode body 330C through the electrode body. The electrode body 330B can further comprise an aperture 338C for accommodating wiring that provides electricity for ablation. The aperture 338C can be an additional through-hole extending through the electrode body 330C. The aperture 338C can extend parallel to the lumen 336C.

[0043] Examples of materials that are ideally suitable for forming the electrode bodies described herein include gold, platinum, and palladium (and their respective alloys). These materials also have high thermal conductivity, which enables minimal heat generated on the tissue (i.e., due to the ablation energy delivered to the tissue) to be conducted through the electrode body to the bottom surface of the electrode (i.e., the portion of the electrode inside the spine) and then to the blood pool within the heart 12. Additionally, a conductive polymer material can be disposed along the outer surface of the electrode body.

[0044] Regarding this technology, the high-permeability materials described herein can be made from any material, and materials with higher permeability are more suitable. Magnetic field lines preferentially pass through materials with high permeability. In various embodiments of this technology, mu (μ) metal, amorphous metal alloys (also known as metallic glass alloys), nanocrystalline metals, or 99.95% pure iron can be used. One particular branch of mu metal and Metglas® amorphous alloys (METGLAS is a registered trademark of Metglas, Inc. (Conway, South Carolina)) are both particularly well-suited for use with the members of this disclosure. Compared to air, which has a permeability equal to 1 (i.e., μ = 1), mu metal has a relative permeability of approximately 50,000, while 99.95% pure iron has been found to have a relative permeability of approximately 200,000.

[0045] The technology of this disclosure described herein can be further understood in accordance with the following clauses.

[0046] Clause 1: An electrode assembly comprising an electrode body having a top surface and a bottom surface and configured to deliver ablation energy to tissue through at least the top surface, a coil disposed near the bottom surface and configured to generate a voltage when exposed to a magnetic field, and a member disposed near the coil and including a high-permeability material.

[0047] Clause 2: The electrode assembly of Clause 1, wherein the member is disposed between the coil and the electrode body, and the member is attached to the bottom surface of the electrode body.

[0048] Clause 3: The electrode assembly of Clause 2, further comprising an insulating material disposed between the member and the bottom surface of the electrode body.

[0049] Clause 4: The electrode assembly of Clause 1, wherein the coil is disposed between the member and the electrode body, and the coil is attached to the bottom surface of the electrode body.

[0050] Clause 5: The electrode assembly according to clause 4, further comprising an insulating material disposed between the coil and the bottom surface of the electrode body.

[0051] Clause 6: The electrode assembly according to clause 1, wherein a member is at least partially disposed within the electrode body.

[0052] Clause 7: The electrode assembly according to any of the preceding clauses, wherein the electrode body further comprises a lumen extending therethrough, the lumen being configured to receive a spine of an end effector.

[0053] Clause 8: The electrode assembly according to any of the preceding clauses, wherein the coil comprises a single axis sensor (SAS).

[0054] Clause 9: The electrode assembly according to any of the preceding clauses, wherein the coil comprises a flexible circuit.

[0055] Clause 10: The electrode assembly according to any of the preceding clauses, wherein the high permeability material comprises mu-metal.

[0056] Clause 11: The electrode assembly according to any of the preceding clauses, further comprising a conductive polymer material disposed along the outer surface of the electrode body.

[0057] Clause 12: A medical device comprising a flexible shaft extending along a longitudinal axis, a plurality of spines disposed at a distal end of the flexible shaft, the plurality of spines being configured to deflect radially outward from the longitudinal axis and to transition between an expanded configuration and a collapsed configuration, and a plurality of electrode assemblies attached to the plurality of spines, each electrode assembly of the plurality of electrode assemblies comprising a top surface and a bottom surface, an electrode body configured to deliver ablation energy to tissue through at least the top surface, a coil disposed near the bottom surface and configured to generate a voltage when exposed to a magnetic field, and a member disposed near the coil and comprising a high permeability material.

[0058] Clause 13: The medical device according to clause 12, wherein a member is disposed between the coil and the electrode body, and the member is attached to the bottom surface of the electrode body.

[0059] Clause 14: The medical device according to clause 13, further comprising an insulating material disposed between the member and the bottom surface of the electrode body.

[0060] Clause 15: The medical device according to clause 12, wherein a coil is disposed between the member and the electrode body, and the coil is attached to the bottom surface of the electrode body.

[0061] Clause 16: The medical device according to clause 15, further comprising an insulating material disposed between the coil and the bottom surface of the electrode body.

[0062] Clause 17: The medical device according to clause 12, wherein the member is at least partially disposed within the electrode body.

[0063] Clause 18: The electrode body further comprises a lumen extending therethrough, the lumen being configured to receive a spine of an end effector, the medical device according to any one of clauses 12 - 17.

[0064] Clause 19: The medical device according to any one of clauses 12 - 18, wherein the coil comprises a flexible circuit.

[0065] Clause 20: The medical device according to any one of clauses 12 - 19, wherein the high permeability material comprises mu-metal.

[0066] Clause 21: The medical device according to any one of clauses 12 - 20, further comprising a conductive polymer material disposed along an outer surface of the electrode body.

[0067] Clause 22: The medical device according to any one of clauses 12 - 21, wherein the coil comprises a single axis sensor (SAS).

[0068] The above-described embodiments are cited as examples, and the present invention is not limited to those specifically illustrated and described heretofore. Rather, the scope of the present invention includes both various combinations of the features described herein heretofore and partial combinations thereof, as well as those variations and modifications thereof that are not disclosed in the prior art and would be contemplated by those skilled in the art upon reading the above description.

[0069] 〔Embodiment〕 (1) An electrode body having a top surface and a bottom surface and configured to deliver ablation energy to tissue through at least the top surface, a coil disposed near the bottom surface and configured to generate a voltage when exposed to a magnetic field, and a member disposed near the coil and including a high magnetic permeability material, an electrode assembly. (2) The electrode assembly according to Embodiment 1, wherein the member is disposed between the coil and the electrode body, and the member is attached to the bottom surface of the electrode body. (3) The electrode assembly according to Embodiment 2, further comprising an insulating material disposed between the member and the bottom surface of the electrode body. (4) The electrode assembly according to Embodiment 1, wherein the coil is disposed between the member and the electrode body, and the coil is attached to the bottom surface of the electrode body. (5) The electrode assembly according to Embodiment 4, further comprising an insulating material disposed between the coil and the bottom surface of the electrode body.

[0070] (6) The electrode assembly according to Embodiment 1, wherein the member is at least partially disposed within the electrode body. (7) The electrode assembly according to Embodiment 1, wherein the electrode body further comprises a lumen extending through the electrode body, and the lumen is configured to receive a spine of an end effector. (8) The electrode assembly according to Embodiment 1, wherein the coil comprises a single axis sensor (SAS). (9) The electrode assembly according to Embodiment 1, wherein the coil comprises a flexible circuit. (10) The electrode assembly according to Embodiment 1, wherein the high magnetic permeability material contains mu-metal.

[0071] (11) The electrode assembly according to Embodiment 1, further comprising a conductive polymer material disposed along an outer surface of the electrode body. (12) A medical device, a flexible shaft extending along a longitudinal axis, a plurality of spines disposed at a distal end of the flexible shaft, the plurality of spines being configured to bend radially outward from the longitudinal axis and to transition between an expanded configuration and a collapsed configuration, a plurality of electrode assemblies attached to the plurality of spines, each electrode assembly of the plurality of electrode assemblies comprising an electrode body having a top surface and a bottom surface and configured to deliver ablation energy to tissue at least through the top surface, a coil disposed near the bottom surface and configured to generate a voltage when exposed to a magnetic field, a member disposed near the coil and containing a high magnetic permeability material. (13) The medical device according to Embodiment 12, wherein the member is disposed between the coil and the electrode body, and the member is attached to the bottom surface of the electrode body. (14) The medical device according to Embodiment 13, further comprising an insulating material disposed between the member and the bottom surface of the electrode body. (15) The medical device according to Embodiment 12, wherein the coil is disposed between the member and the electrode body, and the coil is attached to the bottom surface of the electrode body.

[0072] (16) The medical device according to Embodiment 15, further comprising an insulating material disposed between the coil and the bottom surface of the electrode body. (17) The medical device according to embodiment 12, wherein the member is at least partially disposed within the electrode body. (18) The medical device according to embodiment 12, wherein the electrode body further comprises a lumen extending through the electrode body, the lumen being configured to receive a spine of an end effector. (19) The medical device according to embodiment 12, wherein the coil comprises a flexible circuit. (20) The medical device according to embodiment 12, wherein the high permeability material comprises mu-metal.

Claims

1. an electrode body having a top surface and a bottom surface and configured to deliver ablation energy to tissue through at least the top surface; a coil disposed near the bottom surface and configured to generate a voltage when exposed to a magnetic field; a member disposed proximate the coil and comprising a high magnetic permeability material.

2. The electrode assembly of claim 1 , wherein the member is disposed between the coil and the electrode body, the member being attached to the bottom surface of the electrode body.

3. The electrode assembly of claim 2 , further comprising an insulating material disposed between the member and the bottom surface of the electrode body.

4. The electrode assembly of claim 1 , wherein the coil is disposed between the member and the electrode body, the coil being attached to the bottom surface of the electrode body.

5. The electrode assembly of claim 4 , further comprising an insulating material disposed between the coil and the bottom surface of the electrode body.

6. The electrode assembly of claim 1 , wherein the member is at least partially disposed within the electrode body.

7. The electrode assembly of claim 1 , wherein the electrode body further comprises a lumen extending therethrough, the lumen configured to receive a spine of an end effector.

8. The electrode assembly of claim 1 , wherein the coil comprises a single axis sensor (SAS).

9. The electrode assembly of claim 1 , wherein the coil comprises a flexible circuit.

10. The electrode assembly of claim 1 , wherein the high magnetic permeability material comprises a mu metal.

11. The electrode assembly of claim 1 , further comprising a conductive polymer material disposed along an outer surface of the electrode body.

12. 1. A medical device comprising: a flexible shaft extending along a longitudinal axis; a plurality of spines disposed at a distal end of the flexible shaft, the spines configured to deflect radially outward from the longitudinal axis and transition between an expanded configuration and a collapsed configuration; a plurality of electrode assemblies attached to the plurality of spines, each electrode assembly of the plurality of electrode assemblies comprising: an electrode body having a top surface and a bottom surface and configured to deliver ablation energy to tissue through at least the top surface; a coil disposed near the bottom surface and configured to generate a voltage when exposed to a magnetic field; a member disposed near the coil and including a high magnetic permeability material.

13. The medical device of claim 12 , wherein the member is disposed between the coil and the electrode body, the member being attached to the bottom surface of the electrode body.

14. The medical device of claim 13 , further comprising an insulating material disposed between the member and the bottom surface of the electrode body.

15. The medical device of claim 12 , wherein the coil is disposed between the member and the electrode body, the coil being attached to the bottom surface of the electrode body.

16. 16. The medical device of claim 15, further comprising an insulating material disposed between the coil and the bottom surface of the electrode body.

17. The medical device of claim 12 , wherein the member is at least partially disposed within the electrode body.

18. The medical device of claim 12 , wherein the electrode body further comprises a lumen extending therethrough, the lumen configured to receive a spine of an end effector.

19. The medical device of claim 12 , wherein the coil comprises a flexible circuit.

20. 13. The medical device of claim 12, wherein the high magnetic permeability material comprises a mu metal.

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