Coated end effector electrodes for sensing and ablation

Abstract

To provide medical probes. [Solution] A medical probe may include electrodes for ablation, for sensing proximity to tissue, and / or for monitoring electrical signals within the cardiovascular system to identify aberrant-conducting tissue sites causing arrhythmias. The electrodes may be oriented on an end-effector assembly, such as a basket assembly, so that one side of the electrode is positioned to contact the tissue and the opposite side is prevented from contacting the tissue. To enable both efficient energy delivery and high sensitivity for ECG sensing, an impedance-reducing coating may be positioned on the tissue-contact side, and an impedance-increasing coating may be applied to the opposite side. The impedance-increasing coating on an IRE electrode may be thin enough to allow energy to be delivered through the coating during ablation. An RF electrode may have a mass sufficient to carry electrical energy for thermal ablation.

Description

Technical Field

[0001] The present invention generally relates to medical devices, and more particularly to medical probes such as catheters configured to sense tissue proximity and deliver ablation therapy.

Background Art

[0002] Cardiac arrhythmias such as atrial fibrillation (AF) occur when areas of cardiac tissue conduct electrical signals abnormally to adjacent tissue. This disrupts the normal cardiac cycle and causes an asynchronous rhythm. Certain procedures that exist for treating arrhythmias include surgically destroying the source of the signals that cause the arrhythmia and destroying the conduction pathways of such signals. It is sometimes possible to stop or alter the propagation of unwanted electrical signals from one part of the heart to another by selectively ablating cardiac tissue by applying energy via a catheter.

[0003] Many modern catheter-based ablation approaches utilize radiofrequency (RF) electrical energy to heat tissue. Cryoablation is an alternative catheter-based approach to RF ablation that neutralizes electrical signals through tissue with low temperatures rather than heat. Irreversible electroporation (IRE) is a recent catheter-based electrical ablation approach for ablating cardiac tissue using non-thermal ablation. To achieve IRE, short pulses of high-voltage electrical signals are delivered to the tissue. The electrical signals generate irreversible permeabilization of the cell membrane. Delivery of IRE energy to tissue using multi-electrode catheters has been previously proposed in the patent literature. Examples of systems and apparatus configured for IRE ablation are disclosed in U.S. Patent Applications Publications 2021 / 0169550(A1), 2021 / 0169567(A1), 2021 / 0169568(A1), 2021 / 0161592(A1), 2021 / 0196372(A1), 2021 / 0177503(A1), and 2021 / 0186604(A1), each of which is incorporated herein by reference.

[0004] Areas of cardiac tissue can be mapped by catheter to identify abnormal electrical signals. Ablation can be performed using the same or different catheters. Areas of cardiac tissue can be mapped by catheter to identify abnormal electrical signals. Ablation can be performed using the same or different catheters. Some catheter ablation procedures, particularly those involving persistent atrial fibrillation, can be performed using electrophysiological (EP) mapping to target areas of abnormal electrical signals. Such EP mapping may involve the use of sensing electrodes configured to monitor electrical signals within the cardiovascular system to precisely indicate the location of abnormal conductive tissue sites involved in arrhythmias. An example of an EP mapping system is described in U.S. Patent No. 5,738,096, which is incorporated herein by reference and attached to the appendix herein. Examples of EP mapping catheters are described in U.S. Patent No. 9,907,480, U.S. Patent Publication No. 2018 / 0036078, and U.S. Patent Publication No. 2018 / 0056038, each of which is incorporated herein by reference and attached to the appendix herein.

[0005] In addition to using EP mapping, some catheter ablation procedures may be performed using image-guided surgery (IGS) systems. IGS systems may allow physicians to visually track the position of the catheter within the patient in real time in relation to images of anatomical structures within the patient. Several systems may offer a combination of EP mapping and IGS functionality, including the CARTO 3® system by Biosense Webster, Inc. (Irvine, California). Examples of catheters configured for use with IGS systems are disclosed in U.S. Patent No. 9,480,416, which is incorporated herein by reference. [Overview of the project] [Means for solving the problem]

[0006] Medical probes may include electrodes configured to perform electrical ablation using IRE and / or thermal ablation, and may also be configured for sensing functions such as sensing proximity to tissue and / or monitoring electrical signals within the cardiovascular system to identify aberrant-conducting tissue sites causing arrhythmias. When configured for thermal ablation, the electrodes have sufficient mass to carry electrical energy and provide thermal conductivity and stability for thermal ablation. The electrodes may be oriented on an end-effector assembly, such as a basket assembly, so that one side of the electrode is positioned to contact the tissue and the opposite side is prevented from contacting the tissue. To enable both efficient energy delivery and high sensitivity for ECG sensing, an impedance-reducing coating may be positioned on the tissue-contact side, and an impedance-increasing coating may be applied to the opposite side. When configured for IRE, the impedance-increasing coating is configured to provide sufficient electrical resistance to offer specificity for tissue proximity index measurement, while being thin enough to allow electrical energy to be delivered through the impedance-increasing coating during IRE.

[0007] An exemplary medical probe includes a shaft, a plurality of spines, and a plurality of electrodes. The shaft extends along its longitudinal axis. The plurality of spines extend from the distal end of the shaft and are configured to extend away from the longitudinal axis to form an elastic basket. Each of the plurality of electrodes includes a conductive body surrounding each of the plurality of spines, an impedance-reducing coating on the outer surface of the conductive body such that the outer surface of the conductive body faces away from the longitudinal axis, and an impedance-increasing coating on the inner surface of the conductive body such that the inner surface of the conductive body faces toward the longitudinal axis.

[0008] An exemplary method provides a medical probe having a shaft extending along a longitudinal axis, a plurality of spines extending from the distal end of the shaft and configured to expand away from the longitudinal axis to form an elastic basket, and a plurality of electrodes, each having a conductive body surrounding each of the plurality of spines, and includes applying an impedance-reducing coating to the outer surface of each conductive body of each electrode of the plurality of electrodes such that the outer surface of each conductive body faces away from the longitudinal axis, and applying an impedance-increasing coating to the inner surface of each conductive body such that the inner surface faces toward the longitudinal axis.

[0009] An exemplary system comprises a medical probe and a console. The medical probe includes a shaft, one or more spines extending from the distal end of the shaft, and a plurality of electrodes, each having a conductive body surrounding each of the one or more spines. Each of the plurality of electrodes has an impedance-reducing coating on a first surface of its conductive body and an impedance-increasing coating on a second surface of its conductive body. The console includes at least one processor and a non-transient computer-readable medium communicating with the at least one processor. The non-transient computer-readable medium, when executed by the processor, includes instructions that cause the console to sense contact between at least a portion of the plurality of electrodes and tissue, and to provide electrical energy to at least a portion of the plurality of electrodes to ablate the tissue, based in part on impedance measurements between one or more electrode pairs of the plurality of electrodes. [Brief explanation of the drawing]

[0010] This specification concludes with claims that specifically point to and explicitly assert rights to the subject matter described herein, which is considered to be better understood from the following description of specific embodiments taken in conjunction with the accompanying drawings. In the drawings, similar reference numerals indicate the same elements. The drawings depict one or more implementations of the apparatus of the present invention, not as limitations but merely as examples. [Figure 1] This is a diagram illustrating an exemplary catheter-based electrophysiological mapping and ablation system according to an aspect of the present invention. [Figure 2] This is a diagram of the distal portion of a catheter according to an aspect of the present invention. [Figure 3A] This is a diagram showing both sides of an electrode according to an embodiment of the present invention. [Figure 3B] This is a diagram showing both sides of an electrode according to an embodiment of the present invention. [Figure 4] This is a flowchart of method 100 for constructing coated electrodes for electrocardiogram sensing. [Modes for carrying out the invention]

[0011] The following detailed description should be read in reference to the drawings, where similar elements in different drawings are numbered identically. The drawings are not necessarily to scale, depict selected embodiments, and are not intended to limit the scope of the invention. The detailed description illustrates the principles of the invention as examples, rather than being limiting. This description describes several embodiments, adaptations, modifications, substitutions, and uses of the invention, including those currently considered to be the best modes for carrying out the invention, which will make it clear to those skilled in the art that the invention can be made and used.

[0012] Where used herein, the terms “approximately” or “about” for any number or range indicate a preferred dimensional tolerance that enables some or all of the components to function for the intended purposes described herein. More specifically, “about” or “nearly” may refer to a range of values ​​within ±10% of the enumerated values, while “about 90%” may refer to a range of values ​​between 81% and 99%.

[0013] In addition, as used herein, the terms “patient,” “host,” “user,” and “subject” refer to any human or animal subject, and while the use of the present invention in a human patient represents a preferred embodiment, it is not intended to limit the system or method to human use. Similarly, the term “proximal” refers to a location closer to the operator, while “distal” refers to a location further away from the operator or physician.

[0014] Features of alternative devices and systems, as well as alternative method steps, are presented in the exemplary embodiments herein. Each given exemplary embodiment presented herein can be modified to include features and / or method steps presented together with other exemplary embodiments herein, but such features and / or steps are interchangeable with the given embodiment, as can be understood by those skilled in the art and where expressly stated herein. Such modifications and variations are intended to be included in the claims.

[0015] Electrodes positioned on the end effector of a catheter, configured for energy delivery and ECG sensing, are typically selected to have low impedance to enable both efficient energy delivery and high sensitivity for ECG sensing. Electrodes with high energy delivery, particularly those for delivering RF electrical signals for thermal ablation, require sufficient mass to carry electrical and thermal energy. For this purpose, cylindrical electrodes can be used because they have greater mass than alternative electrode shapes such as surface-mount electrodes and / or flex-circuit electrodes. Cylindrical electrodes have straight, parallel sides and a circular, elliptical, or rounded rectangular cross-section with a central opening. Cylindrical electrodes can be screwed onto the spine of the end effector at the distal end of a medical probe. A cylindrical electrode is an example of an electrode shape that includes a conductive body surrounding the spine of the end effector. However, the examples herein may be modified to include electrodes having alternative shapes, as will be understood by those skilled in the art.

[0016] Local tissue proximity indicator (TPI) detection is based on sensing the impedance between electrodes. The detected impedance increases significantly when the electrical signal between electrodes passes through or near a tissue wall compared to when the electrical signal passes completely through the blood pool. When using cylindrical electrodes, the electrical signal is distributed across the entire electrode, i.e., the front and back surfaces. However, the back surface of the electrode is always in the blood pool. Due to the low impedance contact of the back surface of the electrode to the blood, the overall detected change in impedance when the front surface of the electrode is in contact with tissue may be small. Assessment of tissue contact can be determined based on sensing the impedance between electrodes by various methods, such as those disclosed in U.S. Patent No. 11,523,750, which is incorporated herein by reference and attached to the Annexes herein.

[0017] Embodiments presented herein include an impedance-reducing coating on the front side of the electrode and an impedance-increasing coating on the back side of the electrode. As a result, the impedance on the back side of the electrode through the blood increases, and the impedance on the front side of the contact changes more dramatically compared to tissue when in contact with blood. Consequently, the overall change in impedance between electrodes when the electrode is in contact with tissue is greater compared to a similarly configured electrode without back and front coatings. Thus, electrode coatings can make TPI impedance measurements more sensitive in at least some applications. Some embodiments present catheters configured for IRE. In such embodiments, the impedance-increasing coating is configured to be thin enough to allow electrical energy to be delivered through the impedance-increasing coating during IRE, while providing sufficient electrical resistance to provide specificity for tissue proximity index measurements. An example of a suitable impedance-reducing coating is Amplicoat®, available from Heraeus Medevio. Amplicoat® is a biocompatible conductive polymer technology. Amplicoat® coatings may be applied by electrodeposition, where an electric current is passed over the surface to grow the coating layer. As those skilled in the art will understand, alternative conductive coatings such as TiOx and IrOx can be used. An example of a suitable impedance-increasing coating is silicon nitride (Si3N4). Silicon nitride coatings may be applied in aerosol deposition. In the examples shown herein, a cassette (electrode shape) facilitates separation between the two coatings in an easy and efficient manner.

[0018] Figure 1 shows an exemplary catheter-based electrophysiological mapping and ablation system 10. The system 10 includes multiple catheters that are inserted percutaneously by a physician 24 through the patient's vascular system into the lumen or vascular structure of the heart 12. Typically, a delivery sheath catheter is inserted into the left or right atrium near a desired location within the heart 12. Multiple catheters can then be inserted into the delivery sheath catheter to reach the desired location. The multiple catheters may include a catheter dedicated to sensing intracardiac electrophysiological (IEGM) signals, a catheter dedicated to ablation, and / or a catheter dedicated to both sensing and ablation. This specification shows an exemplary catheter 14 configured for IRE and / or RF ablation. In some embodiments, catheter 14 is also configured for IEGM sensing. When configured for IRE, having accurate tissue proximity markings is important to ensure that the catheter makes proper contact with the tissue and performs ablation. When configured for RF ablation, it is important that the electrodes have sufficient thermal mass to perform thermal ablation. The physician 24 brings the distal tip 28 of the catheter 14 into contact with the heart wall to sense the target site in the heart 12. For ablation, the physician 24 similarly brings the distal end of the ablation catheter to the target site for ablation.

[0019] The illustrated catheter 14 is an exemplary catheter comprising one, and preferably more than one, electrode 40 optionally distributed across a plurality of spines 22 at a distal tip 28. As shown in the illustration, the spines 22 are molded to form an elastic basket, referred herein to as a basket assembly 100. The electrodes 40 are configured to deliver RF ablation energy to the tissue and function as TPI sensors. Some, or preferably all, of the electrodes 40 include an impedance-reducing coating 42 on the outer (front) surface and an impedance-increasing coating 44 on the inner (back) surface to enhance the sensitivity of TPI measurement.

[0020] The catheter 14 may additionally include a position sensor 29 embedded in 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 including three magnetic coils for sensing three-dimensional (3D) position and orientation. The magnetic-based position sensor 29 may work in conjunction with a position pad 25 including a plurality of magnetic coils 32 configured to generate a magnetic field within a given working range. 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 technology are described in U.S. Patents 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, and 6,892,091, which are incorporated herein by reference.

[0021] System 10 includes one or more electrode patches 38 positioned for skin contact on a patient 23 to establish a positional reference for the position pad 25. The distal tip 28 of the catheter may include impedance-based tracking of an electrode 40 or additional electrodes (not shown). For impedance-based tracking, a current is directed toward the electrodes at the distal end of the catheter and sensed at the electrode skin patches 38, thereby allowing the position of each electrode to be triangulated via the electrode patches 38. Details of impedance-based location tracking techniques are described in U.S. Patents 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, which are incorporated herein by reference.

[0022] Recorder 11 displays the electrocardiogram 21 captured by the body surface ECG electrodes 18 and the intracardiac electrogram (IEGM) captured by the electrodes 40 of the catheter 14. Recorder 11 may include pacing capabilities for pacing the heartbeat rhythm and / or may be electrically connected to an independent pacemaker.

[0023] System 10 may include an ablation energy generator 50 adapted to conduct ablation energy to the electrodes 40. The energy produced by the ablation energy generator 50 may include radiofrequency (RF) energy or pulsed-field ablation (PFA) energy, or a combination thereof, including monopolar or bipolar high voltage DC pulses that may be used to effect irreversible electroporation (IRE), but is not limited thereto.

[0024] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheter, the electrophysiological device, the power source, and the workstation 55 for controlling the operation of the system 10. The electrophysiological devices of the system 10 may include, for example, a plurality of catheters (including the catheter 14), the position pads 25, the body surface ECG electrodes 18, the electrode patches 38, the ablation energy generator 50, and the recorder , and the recorder 11. Optionally and preferably, the PIU 30 includes processing capabilities for performing real-time calculations of the position of the catheter, sensing the tissue proximity of the electrodes 40, controlling ablation energy to the electrodes 40, and performing ECG calculations.

[0025] The workstation 55 includes memory, a processor unit having memory or storage device loaded with appropriate operating software, and user interface functions. The workstation 55 can be configured to provide several functions, optionally including: (1) modeling the endocardial anatomical structure in three dimensions (3D) and rendering the model or anatomical map 20 for display on a display device 27; (2) displaying on the display device 27 an activation sequence (or other data) compiled from recorded electrophoresis 21 as representative visual markers or images superimposed on the rendered anatomical map 20; (3) displaying the real-time location and orientation of multiple catheters within the cardiac chambers; and (4) displaying on the display device 27 a site of interest, such as where ablation energy has been applied. One commercially available product embodying the elements of system 10 is available as the CARTO® 3 system, commercially available from Biosense Webster, Inc. (California).

[0026] The PIU30 and / or workstation 55 includes a console housed within the PIU30 and / or workstation 55, or separated between the PIU30 and the workstation 55. The console is configured to control the ablation output and measure tissue proximity via the electrodes 40. The console includes at least one processor and a non-temporary computer-readable medium that communicates with the at least one processor. The non-temporary computer-readable medium, when executed by the processor, includes instructions that cause the console to sense contact between at least some of the electrodes and tissue, based in part on impedance measurements between one or more electrode pairs of the plurality of electrodes, and to provide electrical energy to at least some of the electrodes to ablate the tissue.

[0027] The impedance measurement between electrode pairs can be at least partially based on the impedance of the impedance-reducing coating 42 and the impedance-increasing coating 44 of electrode 40. The console may be configured to sense contact between at least a portion of electrode 40 and tissue, based at least partially on impedance measurements between one or more electrode pairs, and assuming that the impedance-increasing coating of each electrode in the multiple pairs is in contact with blood. Optionally, the console may also be configured to generate an electrocardiogram based at least partially on electrical signals received from at least a portion of electrode 40.

[0028] Figure 2 is a diagram of the distal end 28 of the catheter 14, showing the distal portion of the shaft 84 and the end effector having the spine 72 and electrodes 40. The shaft extends along the longitudinal axis 86. The spine 72 extends from the distal end 90 of the shaft 84 and is configured to expand away from the longitudinal axis 84 to form an elastic basket. Each electrode has a conductive body, an impedance-reducing coating 42, and an impedance-increasing coating 44. The conductive body surrounds each spine 72. The conductive body is oriented such that its outer surface faces away from the longitudinal axis and its inner surface faces toward the longitudinal axis. Thus, the inner surface is prevented from contacting tissue and therefore comes into contact with blood (or other bodily fluids) when the end effector is placed in the patient's body. The outer surface is positioned to be able to contact tissue. Each electrode 40 includes an impedance-reducing coating 42 on the outer surface of each conductive body and an impedance-increasing coating 44 on the inner surface of each conductive body.

[0029] Each electrode 40 is configured to sense tissue contact and provide ablation energy. In some embodiments, the impedance-reducing coating comprises a conductive polymer. In some embodiments, the impedance-increasing coating comprises a ceramic. In some embodiments, the impedance-increasing coating has a thermal conductivity of about 7 W / mK to about 30 W / mK, or about 7 W / mK to about 28 W / mK, or about 30 W / mK. In some embodiments, the impedance-increasing coating comprises silicon nitride. In some embodiments, the electrode 40 is configured for electrocardiogram sensing.

[0030] As will be understood by those skilled in the art, the end effector can have a variety of alternative configurations, including alternative basket assembly configurations, as well as radial or spade-shaped configurations. In such configurations, the electrode 40 may be positioned, as will be understood by those skilled in the art, with an impedance-reducing coating 42 on its surface that can come into contact with tissue and an impedance-increasing coating 44 on its surface that prevents it from coming into contact with tissue when the end effector is placed in the patient's body, and may be otherwise configured.

[0031] Figures 3A and 3B are diagrams of both sides of the electrode 40. The electrode 40 has a cylindrical conductive body 46 with an opening 48 passing through its interior. The size of the conductive body 46 is configured to provide sufficient thermal mass so that the electrode 40 can deliver RF energy to the tissue without causing thermal damage to the end effector. The opening 48 is sized to accommodate the spine 72 so that the electrode 40 can be screwed onto the spine 72 during manufacturing. As shown, the cross-section of the conductive body 46 has a rounded rectangle or stadium shape with straight sides corresponding to the outer and inner surfaces and a rounded side extending between the outer and inner surfaces. The shape of the conductive body 46 facilitates the application of impedance-reducing coatings 42 and impedance-increasing coatings 44 to both sides of the conductive body 46 without overlapping. The conductive body 46 may have alternative cross-sectional shapes (e.g., circular, rectangular, elliptical, triangular, etc.) as will be understood by those skilled in the art. As shown in the figure, the coatings 42 and 44 do not significantly affect the overall shape of the electrode 40.

[0032] As shown in the figure, the opening 48 is also a rounded rectangle or stadium shape. As shown in the figure, the opening 48 is located in the center left and right and offset outward from the center. The opening 48 may be offset to provide desired heat conduction to tissue and heat dissipation to blood.

[0033] Figure 3A shows the front or outer surface of the electrode 40 showing the impedance-reducing coating 42 on the front or outer surface of the conductive body 46. As shown, the impedance-reducing coating 42 is limited to the flat portion of the outer surface. The outer surface is shaped so that when in contact with tissue during treatment, the entire flat surface is in contact with the tissue, and the curved edges of the outer surface are in partial contact with the tissue. The advantage of this configuration is that when the outer surface is in contact with tissue, the entire impedance-reducing coating 42 is in contact with the tissue, and there is no portion in contact with blood. A low-resistance path through the blood reduces TPI sensitivity. By positioning the impedance-reducing coating 42 so that the entire coating 42 is in contact with the tissue, the coating does not provide a low-resistance path through the blood when the electrode 40 is in contact with tissue. Alternatively, the impedance-reducing coating 42 can be applied over a portion of the curved surface of the outer surface.

[0034] Figure 3B shows the back or inner surface of the electrode 40 showing an impedance-enhancing coating 44 on the back or inner surface of the conductive body 46. As shown, the impedance-enhancing coating 44 is limited to a flat portion of the inner surface. The inner surface may be molded to facilitate the movement of the end effector (e.g., expansion and contraction of the basket assembly). The impedance-enhancing coating 44 may be limited to areas that are not intended, expected, and / or configured to come into contact with tissue when the end effector is placed in a patient. Alternatively, the impedance-enhancing coating 44 may extend around the surface of the conductive body 46 and terminate adjacent to an impedance-reducing coating 42.

[0035] Figure 4 is a flowchart of method 100 for constructing a coated electrode for electrocardiogram sensing. The resulting electrode can be constructed as well as electrode 40, its substitutes, or variations thereof, as understood by those skilled in the art in accordance with the disclosure herein.

[0036] In block 102, the impedance-reducing coating may be applied to the outer surface of each conductive body of one of the multiple electrodes of the basket catheter end effector such that the outer surface of each electrode faces away from the longitudinal axis. In some embodiments, the impedance-reducing coating is applied by electrodeposition. In some embodiments, the impedance-reducing coating comprises a conductive polymer. As will be understood by those skilled in the art according to the disclosure herein, the impedance-reducing coating may include materials, substitutes thereof, or variations thereof disclosed elsewhere in this specification, and may be applied as substitutes or variations thereof as disclosed elsewhere in this specification. As will be understood by those skilled in the art according to the disclosure herein, the outer surface may be molded, positioned, and otherwise configured as substitutes or variations thereof as disclosed elsewhere in this specification.

[0037] In block 104, the impedance-enhancing coating may be applied to the inner surface of each conductive body such that the inner surface faces the longitudinal axis. In some embodiments, the impedance-enhancing coating includes ceramic. In some embodiments, the impedance-enhancing coating has a thermal conductivity of about 30 W / mK. In some embodiments, the impedance-enhancing coating includes silicon nitride. As will be understood by those skilled in the art according to the disclosures herein, the impedance-enhancing coating may include materials, substitutes thereof, or variations thereof disclosed elsewhere in this specification, and may be applied as substitutes or variations thereof as disclosed elsewhere in this specification. As will be understood by those skilled in the art according to the disclosures herein, the inner surface may be molded, positioned, and otherwise configured as substitutes or variations thereof as disclosed elsewhere in this specification.

[0038] In block 106, multiple electrodes can be positioned such that the impedance-reducing coating is in contact with the tissue, preventing at least a large portion of the impedance-increasing coating from contacting the tissue. As will be understood by those skilled in the art in accordance with the disclosure herein, the coating may be positioned on the conductive body of the electrode as an alternative or variation thereof, as disclosed elsewhere herein.

[0039] In block 108, each of the multiple electrodes may be configured to sense tissue contact and provide ablation energy. As will be understood by those skilled in the art in accordance with the disclosure herein, the electrodes may be configured to sense tissue contact using TPI measurement techniques, alternatives thereto, or modifications thereof as disclosed elsewhere in this specification. Coatings may be placed on the electrodes to enhance the sensitivity of the TPI measurement. As will be understood by those skilled in the art in accordance with the disclosure herein, the electrodes may be molded, sized, and otherwise configured to provide ablation energy, alternatives thereto, or modifications thereof as disclosed elsewhere in this specification.

[0040] In block 110, each of the multiple electrodes may be configured for electrocardiogram sensing. As will be understood by those skilled in the art in accordance with the disclosure herein, the electrodes may be configured to sense electrical signals through cardiac tissue for electrocardiogram measurement using techniques, alternatives, or variations thereof disclosed elsewhere in this specification.

[0041] The following clauses enumerate non-limiting embodiments of this disclosure.

[0042] Clause 1. A medical probe comprising: a shaft (84) extending along a longitudinal axis (86); a plurality of spines (72) extending from the distal end (90) of the shaft (84) and configured to expand away from the longitudinal axis to form an elastic basket; and a plurality of electrodes (40), wherein each of the plurality of electrodes comprises a conductive body surrounding each of the plurality of spines; an impedance-reducing coating (42) on the outer surface of the conductive body such that the outer surface faces away from the longitudinal axis; and an impedance-increasing coating (44) on the inner surface of the conductive body such that the inner surface faces toward the longitudinal axis.

[0043] Clause 2. The medical probe described in Clause 1, wherein each of the multiple electrodes is configured to sense tissue contact and provide ablation energy.

[0044] Clause 3. The impedance-reducing coating is a medical probe as described in Clause 1 or 2, comprising a conductive polymer.

[0045] Clause 4. Impedance-enhancing coatings include ceramics, as described in any one of Clauses 1 to 3.

[0046] Clause 5. The impedance-enhancing coating is a medical probe as described in any one of Clauses 1 to 4, having a thermal conductivity of approximately 30 W / mK.

[0047] Clause 6. The impedance-enhancing coating is Si3N4, as described in any one of Clauses 1 to 5.

[0048] Clause 7. A medical probe as described in any one of Clauses 1 to 6, in which each of the multiple electrodes is configured for electrocardiogram sensing.

[0049] Clause 8. An impedance-reducing coating is thinner than an impedance-increasing coating, and is used for medical probes as described in any one of Clauses 1 to 7.

[0050] Clause 9. A medical probe as described in any one of Clauses 1 to 8, configured to provide irreversible electroporation to tissue.

[0051] Clause 10. A medical probe as described in any one of Clauses 1 to 9, configured to provide radiofrequency ablation to tissue with multiple electrodes.

[0052] Clause 11. An impedance-reducing coating is a medical probe described in any one of Clauses 1 to 10, which includes an impedance lower than that of an impedance-increasing coating.

[0053] Clause 12. A medical probe as described in Clause 11, wherein, when applying irreversible electroporation, the impedance difference between the impedance-reducing coating and the impedance-increasing coating is less than the impedance difference between the impedance-reducing coating and the impedance-increasing coating during electrocardiogram sensing.

[0054] Clause 13. A method to provide a medical probe comprising: a shaft extending along a longitudinal axis; a plurality of spines extending from the distal end of the shaft and configured to expand away from the longitudinal axis to form an elastic basket; and a plurality of electrodes, each having a conductive body surrounding each of the plurality of spines; a method comprising: applying an impedance-reducing coating to the outer surface of each conductive body of each electrode of the plurality of electrodes such that the outer surface of each conductive body faces away from the longitudinal axis; and applying an impedance-increasing coating to the inner surface of each conductive body such that the inner surface faces toward the longitudinal axis.

[0055] Clause 14. The method of Clause 13, wherein applying an impedance-reducing coating includes electrodepositing an impedance-reducing coating.

[0056] Clause 15. The method according to Clause 13 or 14, wherein applying an impedance-enhancing coating includes aerosol deposition of the impedance-enhancing coating.

[0057] Clause 16. An impedance-reducing coating comprising a conductive polymer, as described in any one of Clauses 13 to 15.

[0058] Clause 17. An impedance-increasing coating is a coating made of ceramic, as described in any one of Clauses 13 to 16.

[0059] Clause 18. An impedance-increasing coating having a thermal conductivity of approximately 30 W / mK, as described in any one of Clauses 13 to 17.

[0060] Clause 19. An impedance-increasing coating comprising Si3N4, as described in any one of Clauses 13 to 18.

[0061] Clause 20. The method of any one of Clauses 13 to 19, wherein applying an impedance-reducing coating includes configuring the impedance-reducing coating to come into contact with tissue, and applying an impedance-increasing coating includes positioning the impedance-increasing coating such that at least a large portion of the impedance-increasing coating is prevented from coming into contact with tissue.

[0062] Clause 21. The method according to any one of Clauses 13 to 20, further comprising configuring each electrode of a plurality of electrodes to sense tissue contact and provide ablation energy.

[0063] Clause 22. The method according to any one of Clauses 13 to 21, further comprising configuring each electrode of a plurality of electrodes to sense an electrocardiogram.

[0064] Clause 22. An impedance-reducing coating is thinner than an impedance-increasing coating, as described in any one of Clauses 13 to 21.

[0065] Clause 23. The method described in any one of Clauses 13 to 22, comprising configuring multiple electrodes to provide irreversible electroporation to tissue.

[0066] Clause 24. The method described in any one of Clauses 13 to 23, comprising configuring multiple electrodes to provide radiofrequency ablation to tissue.

[0067] Clause 25. The method described in any one of Clauses 13 to 24, wherein the impedance-reducing coating includes an impedance lower than that of the impedance-increasing coating.

[0068] Clause 26. The method according to any one of Clauses 13 to 25, which includes configuring multiple electrodes such that the impedance difference between the impedance-reducing coating and the impedance-increasing coating is less than the impedance difference between the impedance-reducing coating and the impedance-increasing coating during electrocardiogram sensing.

[0069] Clause 27. A medical probe comprising a shaft, one or more spines extending from the distal end of the shaft, and a plurality of electrodes, each having a conductive body surrounding each of the one or more spines, wherein each of the plurality of electrodes comprises an impedance-reducing coating on a first surface of the conductive body and an impedance-increasing coating on a second surface of the conductive body; and a console comprising at least one processor and a non-temporary computer-readable medium communicating with the at least one processor and containing instructions, wherein, when executed by the processor, the console causes the console to sense contact between at least a portion of the plurality of electrodes and tissue, and to provide electrical energy to at least a portion of the plurality of electrodes to ablate tissue, based in part on impedance measurements between one or more pairs of electrodes of the plurality of electrodes.

[0070] The system described in Clause 27, wherein the impedance measurement between one or more electrode pairs is at least partially based on the impedance of the impedance-reducing coating and the impedance of the impedance-increasing coating of each electrode in one or more electrode pairs.

[0071] Clause 29. A non-temporary computer-readable medium, when executed by a processor, includes instructions causing the console to sense contact between at least a portion of a plurality of electrodes and tissue, based in part on impedance measurements between one or more electrode pairs, and assuming that the impedance-increasing coating of each electrode in one or more electrode pairs is in contact with blood, as described in Clause 27 or 28.

[0072] Clause 30. Electrical energy, including high-frequency ablation energy, in any of the systems described in any one of Clauses 27 to 29.

[0073] Clause 31. An impedance-reducing coating is a system described in any one of Clauses 27 to 30, comprising a conductive polymer.

[0074] Clause 32. Impedance-increasing coatings include ceramics, as described in any one of Clauses 27 to 31.

[0075] Clause 33. An impedance-increasing coating having a thermal conductivity of approximately 30 W / mK, as described in any one of Clauses 27 to 32.

[0076] Clause 34. The impedance-reducing coating is thinner than the impedance-increasing coating in any one of the systems described in Clauses 27-33.

[0077] Clause 35. The system described in any one of Clauses 27-34, wherein the console is configured to provide irreversible electroporation to tissue by supplying electrical pulses to multiple electrodes.

[0078] Clause 36. The console is configured to provide electrical waveforms to multiple electrodes in order to provide radiofrequency ablation to tissue, as described in any one of Clauses 27 to 35.

[0079] Clause 37. An impedance-reducing coating is a system described in any one of Clauses 27 to 36, which includes an impedance lower than that of an impedance-increasing coating.

[0080] Clause 38. A system according to any one of Clauses 27 to 37, wherein, when applying irreversible electroporation, the impedance difference between the impedance-reducing coating and the impedance-increasing coating is less than the impedance difference between the impedance-reducing coating and the impedance-increasing coating during electrocardiogram sensing.

[0081] While exemplary embodiments of the subject matter included herein have been illustrated and described, further adaptations of the methods and systems described herein can be achieved by appropriate modifications without departing from the claims. For example, alternative materials may be used for the electrode conductive body, impedance-reducing coating, and impedance-increasing coating. The medical probe may have alternative configurations for alternative non-invasive in vivo tissue ablation treatments. The spine of the end effector may have alternative configurations such as star-shaped, radial, or spade-shaped. In addition, where the methods and steps described above indicate specific events occurring in a particular order, the specific steps do not need to be performed in the order described, and are intended to be performed in any order, as long as the steps enable the embodiments to function for their intended purposes. Thus, insofar as there are variations of the invention that are within the spirit of this disclosure or equivalent to the invention found in the claims, this patent is intended to encompass such variations as well. Some such modifications should be obvious to those skilled in the art. For example, the examples, embodiments, geometric shapes, materials, dimensions, proportions, steps, etc., discussed above are exemplary. Therefore, the claims should not be limited to specific details of the structure and operation described in the specification and drawings.

[0082] [Implementation Method] (1) A medical probe, A shaft extending along the longitudinal axis, Multiple spines extending from the distal end of the shaft and expanding away from the longitudinal axis to form an elastic basket, A plurality of electrodes are provided, and each of the plurality of electrodes is Each conductive body surrounding each of the spines among the plurality of spines, An impedance-reducing coating on the outer surface of each of the conductive bodies such that the outer surface faces away from the longitudinal axis, A medical probe comprising an impedance-increasing coating on the inner surface of each conductive body such that the inner surface of each conductive body faces toward the longitudinal axis. (2) The medical probe according to Embodiment 1, wherein each of the plurality of electrodes is configured to sense tissue contact and provide ablation energy. (3) The medical probe according to Embodiment 1, wherein the impedance-reducing coating comprises a conductive polymer. (4) The impedance-increasing coating comprises a ceramic, as described in Embodiment 1 of the medical probe. (5) The impedance-increasing coating has a thermal conductivity of about 7 W / mK to about 30 W / mK, as described in Embodiment 1 of the medical probe.

[0083] (6) The medical probe according to Embodiment 1, wherein the impedance-increasing coating includes Si3N4. (7) The medical probe according to Embodiment 1, wherein each of the plurality of electrodes is configured for electrocardiogram sensing. (8) A method, To provide a medical probe comprising: a shaft extending along a longitudinal axis; a plurality of spines extending from the distal end of the shaft and configured to expand away from the longitudinal axis to form an elastic basket; and a plurality of electrodes, each having a conductive body surrounding each of the plurality of spines. An impedance-reducing coating is applied to the outer surface of the conductive body of each electrode among the plurality of electrodes such that the outer surface of the conductive body faces away from the longitudinal axis, A method comprising applying an impedance-increasing coating to the inner surface of each of the conductive bodies such that the inner surface of each body faces toward the longitudinal axis. (9) The method according to embodiment 8, wherein applying the impedance-reducing coating includes electrodepositing the impedance-reducing coating. (10) The method according to embodiment 8, wherein applying the impedance-increasing coating is aerosol-deposited.

[0084] (11) The method according to any of Embodiment 8, wherein the impedance-reducing coating comprises a conductive polymer. (12) The method according to any of Embodiment 8, wherein the impedance-increasing coating includes a ceramic. (13) A system, A medical probe comprising a shaft, one or more spines extending from the distal end of the shaft, and a plurality of electrodes, each having a conductive body surrounding each of the one or more spines, wherein each of the plurality of electrodes comprises an impedance-reducing coating on a first surface of the conductive body and an impedance-increasing coating on a second surface of the conductive body, A console comprising at least one processor and a non-temporary computer-readable medium that communicates with the at least one processor and contains instructions, wherein when an instruction is executed by the processor, the console displays: Based on the impedance measurements between one or more pairs of electrodes among the plurality of electrodes, contact between at least a portion of the plurality of electrodes and tissue is detected. A system comprising a console that causes electrical energy to be supplied to at least some of the plurality of electrodes in order to ablate tissue. (14) The system according to Embodiment 13, wherein the impedance measurement between the one or more electrode pairs is at least partially based on the impedance of the impedance-reducing coating and the impedance of the impedance-increasing coating of each electrode of the one or more electrode pairs. (15) When the non-temporary computer-readable medium is executed by the processor, the console displays: The system according to Embodiment 13, which includes a command to sense contact between at least some of the plurality of electrodes and tissue, based in part on the impedance measurements between the one or more electrode pairs, and assuming that the impedance-enhancing coating on each electrode of the one or more electrode pairs is in contact with blood.

[0085] (16) The system according to embodiment 13, wherein the electrical energy includes high-frequency ablation energy. (17) The system according to embodiment 13, wherein the impedance-reducing coating comprises a conductive polymer. (18) The system according to embodiment 13, wherein the impedance-increasing coating includes a ceramic. (19) The system according to embodiment 13, wherein the impedance-increasing coating has a thermal conductivity of about 30 W / mK. (20) The system according to embodiment 13, wherein the impedance-increasing coating includes Si3N4.

Claims

1. A medical probe, A shaft extending along the longitudinal axis, Multiple spines extending from the distal end of the shaft and expanding away from the longitudinal axis to form an elastic basket, A plurality of electrodes are provided, and each of the plurality of electrodes is Each conductive body surrounding each of the spines among the plurality of spines, An impedance-reducing coating on the outer surface of each of the conductive bodies such that the outer surface faces away from the longitudinal axis, A medical probe comprising an impedance-increasing coating on the inner surface of each conductive body such that the inner surface of each conductive body faces toward the longitudinal axis.

2. The medical probe according to claim 1, wherein each of the plurality of electrodes is configured to sense tissue contact and provide ablation energy.

3. The impedance-reducing coating comprises a conductive polymer, as described in claim 1, for the medical probe.

4. The impedance-increasing coating comprises ceramic, as described in claim 1, for the medical probe.

5. The impedance-increasing coating has a thermal conductivity of approximately 7 W / mK to approximately 30 W / mK, as described in claim 1, for the medical probe.

6. The impedance-increasing coating is Si ３ N ４ A medical probe according to claim 1, comprising:

7. The medical probe according to claim 1, wherein each of the plurality of electrodes is configured for electrocardiogram sensing.

8. It is a method, To provide a medical probe comprising: a shaft extending along a longitudinal axis; a plurality of spines extending from the distal end of the shaft and configured to expand away from the longitudinal axis to form an elastic basket; and a plurality of electrodes, each having a conductive body surrounding each of the plurality of spines. An impedance-reducing coating is applied to the outer surface of the conductive body of each electrode among the plurality of electrodes such that the outer surface of the conductive body faces away from the longitudinal axis, A method comprising applying an impedance-increasing coating to the inner surface of each of the conductive bodies such that the inner surface of each body faces toward the longitudinal axis.

9. The method according to claim 8, wherein applying the impedance-reducing coating includes electrodepositing the impedance-reducing coating.

10. The method according to claim 8, wherein applying the impedance-increasing coating includes aerosol deposition of the impedance-increasing coating.

11. The method according to any one of claims 8, wherein the impedance-reducing coating comprises a conductive polymer.

12. The method according to any one of claims 8, wherein the impedance-increasing coating includes a ceramic.

13. It is a system, A medical probe comprising a shaft, one or more spines extending from the distal end of the shaft, and a plurality of electrodes, each having a conductive body surrounding each of the one or more spines, wherein each of the plurality of electrodes comprises an impedance-reducing coating on a first surface of the conductive body and an impedance-increasing coating on a second surface of the conductive body, A console comprising at least one processor and a non-temporary computer-readable medium that communicates with the at least one processor and contains instructions, wherein when an instruction is executed by the processor, the console displays: Based in part on the impedance measurements between one or more electrode pairs among the plurality of electrodes, contact between at least a portion of the plurality of electrodes and tissue is detected. A system comprising a console that causes electrical energy to be supplied to at least some of the plurality of electrodes in order to ablate tissue.

14. The system according to claim 13, wherein the impedance measurement between the one or more electrode pairs is at least partially based on the impedance of the impedance-reducing coating and the impedance of the impedance-increasing coating of each electrode of the one or more electrode pairs.

15. When the non-temporary computer-readable medium is executed by the processor, the console displays: The system according to claim 13, comprising a command to sense contact between at least a portion of the plurality of electrodes and tissue, based in part on the impedance measurements between the one or more electrode pairs, and assuming that the impedance-enhancing coating on each electrode of the one or more electrode pairs is in contact with blood.

16. The system according to claim 13, wherein the electrical energy includes high-frequency ablation energy.

17. The system according to claim 13, wherein the impedance-reducing coating comprises a conductive polymer.

18. The system according to claim 13, wherein the impedance-increasing coating includes a ceramic.

19. The system according to claim 13, wherein the impedance-increasing coating has a thermal conductivity of about 30 W / mK.

20. The impedance-increasing coating is Si ３ N ４ The system according to claim 13, including the system described in claim 13.

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