Basket catheter with deformation sensor relying on eddy current

Abstract

To provide a basket catheter and system.SOLUTION: A basket catheter and system is configured to determine a force on a basket assembly of the basket catheter and / or determine deformation of the basket assembly by using a sensor assembly in the basket catheter. The sensor assembly includes a transmitting coil and multiple receiving coils in the catheter shaft, and an electrically conductive plate, disk or ring at a distal end of the basket assembly. The system is configured to provide signals to the transmitting coil to generate a first magnetic field, the first magnetic field causing eddy currents in the electrically conductive plate, disk or ring, the eddy currents generating a second magnetic field. The receiving coils detect superposition of the first and second magnetic fields, and the system determines the force and / or deformation based at least in part on signals from the receiving coils.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Application No. 63 / 507,164, filed June 9, 2023, Attorney Docket No. BIO6818USPSP1-253757.000356, which is incorporated by reference herein as if fully set forth.

[0002] FIELD OF THEINVENTION The present invention relates generally to medical devices, and more particularly to multi-electrode basket catheters. [Background technology]

[0003] Cardiac arrhythmias, such as atrial fibrillation (AF), occur when an area of ​​cardiac tissue abnormally conducts electrical signals to adjacent tissue. This disrupts the normal cardiac cycle and causes asynchronous rhythms. Areas of cardiac tissue can be mapped by catheters to identify abnormal electrical signals. Electrophysiology (EP) mapping can involve the use of sensing electrodes that are configured to monitor electrical signals within the cardiovascular system to pinpoint the location of abnormal conductive tissue sites involved in the arrhythmia. An example of an EP mapping system is described in U.S. Pat. No. 5,738,096, which is incorporated herein by reference.

[0004] By applying energy through the catheter to selectively ablate cardiac tissue, it is sometimes possible to stop or redirect the propagation of undesired electrical signals from one part of the heart to another. The same or a different catheter can be used to perform the ablation. Catheters configured for mapping and / or ablation typically include at least one electrode and / or a multi-electrode end effector coupled to a distal end of the catheter shaft.

[0005] Catheter ablation procedures may be performed using an image guided surgery (IGS) system. An IGS system may allow a physician to visually track the position of the catheter within the patient in real time in conjunction with images of the patient's anatomy. Some systems, including the CARTO 3® system by Biosense Webster, Inc. (Irvine, Calif.), may provide a combination of EP mapping and IGS capabilities.

[0006] Many modern current ablation approaches utilize radiofrequency (RF) electrical energy to heat tissue. Cryoablation and irreversible electroporation (IRE) are alternative ablation techniques. Cryoablation is a process that uses cryogenic temperatures to destroy tissue. Both RF and IRE utilize electrical signals applied to tissue. However, IRE is considered non-thermal because it does not rely on heat to damage tissue. Instead, the electrical signal applied during IRE results in irreversible permeabilization of cell membranes.

[0007] A given catheter for an AF procedure can be configured for mapping, ablation, or both. The distal portion of the catheter is configured to pass through the vasculature and be positioned in the heart and / or adjacent blood vessels. Except for catheters configured specifically for cryoablation, the distal portion of the catheter includes one or more electrodes configured to monitor electrical signals in the cardiovascular system and / or configured for RF and / or IRE ablation. The distal portion of the catheter can have a variety of configurations. A basket catheter is one type of such catheter that has spines extending along a longitudinal axis when collapsed for delivery through the vasculature and that expand away from the longitudinal axis to form a basket shape when deployed at a target site. The spines carry electrodes for sensing and / or ablation. Summary of the Invention [Means for solving the problem]

[0008] Examples presented herein generally include a basket catheter and an IGS system configured to determine forces on a basket assembly of the basket catheter and / or to determine deformation of the basket assembly using a sensor assembly in the basket catheter, the sensor assembly including a transmitting coil and multiple receiving coils in the catheter shaft and a conductive plate, disk, or ring at a distal end of the basket assembly. The IGS system is configured to provide a signal to the transmitting coil to generate a first magnetic field, which induces eddy currents in the conductive plate, disk, or ring, which generate a second magnetic field. The receiving coil detects an overlap of the first and second magnetic fields and transmits a signal to the IGS system, which determines the forces and / or deformation based at least in part on the signal from the receiving coil.

[0009] An exemplary medical probe includes a shaft, a spine, an electrode, a transmit coil, a localization element, and a receive coil. The shaft extends along a longitudinal axis. The spines extend from a distal end of the shaft and are configured to expand away from the longitudinal axis to form an elastic basket. An electrode is coupled to each spine. The transmit coil is disposed within the shaft, aligned along the longitudinal axis, and configured to generate a first alternating magnetic field. The localization element is coupled to a distal end of the spine. The localization element is configured to move relative to the transmit coil in response to a force exerted on the elastic basket. The localization element is configured to generate a second alternating magnetic field based at least in part on the first alternating magnetic field and based in part on a position of the localization element relative to the transmit coil. The receive coils are disposed within the shaft and each configured to output a respective electrical signal based at least in part on an overlap of the first alternating magnetic field and the second alternating magnetic field.

[0010] An exemplary medical system includes a signal generator and a signal processor, the signal generator may be configured to provide an output signal to a transmit coil disposed within a shaft of a medical probe, the signal processor may be configured to receive an input signal from a receive coil disposed within a shaft of a multi-electrode basket catheter, and to determine a position of a conductive non-ferromagnetic element coupled to a distal end of a spine of the multi-electrode basket catheter based at least in part on a comparison of the output signal to the input signal.

[0011] An exemplary method may include one or more of the following steps, performed in various orders and with interleaved steps as will be appreciated by those skilled in the art: generating a first alternating magnetic field from a transmitting coil disposed within a shaft of a multi-electrode basket catheter, inducing eddy currents on a conductive non-ferromagnetic element coupled to a distal spine end of a basket assembly of the multi-electrode basket catheter, inducing respective electrical signals in a receiving coil disposed within the shaft of the multi-electrode basket catheter based at least in part on the overlap of the first and second alternating magnetic fields generated by the eddy currents, and determining a position of the conductive non-ferromagnetic element based at least in part on the respective electrical signals. [Brief description of the drawings]

[0012] While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter described herein, it is believed that the subject matter will be better understood from the following description of specific embodiments taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which: The figures depict one or more implementations of the device of the present invention, by way of illustration only and not by way of limitation. [Figure 1] 1 is a diagram of an exemplary catheter-based electrophysiological mapping and ablation system, in accordance with an aspect of the present invention. [Diagram 2] 1 is a diagram of a distal portion of an exemplary catheter, in accordance with an aspect of the present invention. [Diagram 3] 1 is a diagram of a coil assembly and a localization element of a catheter according to an aspect of the present invention. [Figure 4] FIG. 2 is a diagram of a transmit coil inducing a first alternating magnetic field in accordance with an embodiment of the present invention, the first alternating magnetic field inducing eddy currents on a location element, thereby inducing a second alternating magnetic field. [Figure 5A] 1A-1C show a basket assembly of a catheter deforming in response to a force in the x-direction, according to an embodiment of the invention. [Figure 5B] FIG. 5B is a diagram of a localization element and a receiving coil of the catheter of FIG. 5A, in accordance with an embodiment of the present invention. [Figure 6] 1A-1C show a basket assembly of a catheter deforming in response to a force in the z-direction, according to an embodiment of the invention. [Figure 7] FIG. 11 is a flow diagram illustrating a method for determining a position of an electrically conductive non-ferromagnetic element coupled to a distal end of a basket assembly, according to an aspect of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 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, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates, by way of example and not by way of limitation, the principles of the invention. The description clearly enables one skilled in the art to make and use the invention and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is currently contemplated to be the best mode for carrying out the invention.

[0014] As used herein, the term "about" or "approximately" in relation to any numerical value or range indicates a suitable dimensional tolerance that enables a portion or collection of components to function for the intended purpose described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±10% of the recited value, for example, "about 90%" may refer to a range of values ​​of 81% to 99%.

[0015] Additionally, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject, and while use of the invention in a human patient represents a preferred embodiment, it is not intended to limit the systems or methods 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.

[0016] As used herein, the terms "tubular" and "pipe / tube" are to be interpreted broadly and are not limited to structures that are right cylindrical or strictly circular in cross section, or that are uniform in cross section along their entire length. For example, a tubular structure or system is generally illustrated as a substantially right cylindrical structure. However, a tubular system may have a tapered or curved outer surface without departing from the scope of the invention. A tubular structure or pipe may have a hollow or solid core.

[0017] Alternative apparatus and system features and 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 with different exemplary embodiments herein, but such features and / or steps are compatible with the given embodiment as understood by those skilled in the art and as expressly set forth herein. Such modifications and variations are intended to be included within the scope of the claims.

[0018] FIG. 1 illustrates an exemplary catheter-based electrophysiology mapping and ablation system 10. The system 10 includes multiple catheters that are percutaneously inserted by a physician 24 through a patient's vascular system into a cavity or vasculature 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 catheters dedicated to sensing Intracardiac Electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. The physician 24 brings a basket assembly 36 (end effector) of a distal portion 28 of the catheter 14 into contact with the heart wall to sense IEGM signals and / or ablate a target site within the heart 12. The catheter 14 includes a shaft 16 having a proximal portion that can be manipulated (e.g., by a handle) by a physician 24 outside the patient 23 to position a distal portion of the shaft 16 within the heart 12.

[0019] The depicted catheter 14 is an exemplary catheter that includes one electrode 40, preferably multiple electrodes 40 distributed on multiple spines 42 of the basket assembly 36, configured to sense IEGM signals and / or apply electrical signals for RF and / or IRE ablation. The catheter 14 may further include a position sensor 66 embedded in or near the distal portion 28 (e.g., embedded in the shaft 16 of the catheter 14) and adapted to track the position and orientation of the distal tip 28. Optionally and preferably, the position sensor 66 includes a magnetic-based position sensor including three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0020] The magnetic-based position sensor 66 may operate in conjunction with a location pad 25 including a plurality of magnetic coils 32 configured to generate a magnetic field within a predetermined workspace. The real-time position of the distal portion 28 of the catheter 14 may be tracked based on the magnetic fields generated using the location pad 25 and sensed by the magnetic-based position sensor 66. Navigation signals may be transmitted from the magnetic-based position sensor 66 that may be used by the system 10 to determine the position and orientation of the magnetic-based position sensor 66 within the predetermined workspace. Details of magnetic-based position sensing techniques are described in U.S. Pat. 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] The system 10 includes one or more electrode patches 38 positioned in contact with skin on the patient 23 to establish a reference for locating the locating pads 25 and for impedance-based tracking of the electrodes 40 coupled to the spines 42 and the electrodes 19 coupled to the shaft 16 of the catheter 14 at the distal portion 28. For impedance-based tracking, a current is directed to the electrodes at the distal portion 28 of the catheter 14 and sensed at the electrode skin patches 38, thereby allowing the location of each catheter electrode to be triangulated via the electrode patches 38. Details of impedance-based location tracking technology are described in U.S. Patent Nos. 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 electrograms 21 captured on surface electrocardiogram (ECG) electrodes 18, and may also display IEGM signals captured on electrodes 40 of catheter 14. Recorder 11 may include pacing capability for pacing the cardiac rhythm and / or may be electrically connected to a stand-alone pacer.

[0023] The system 10 may include an ablation energy generator 50 adapted to conduct ablation energy to one or more of the electrodes 40 of the basket assembly 36 configured for ablation. The energy generated by the ablation energy generator 50 may include, but is not limited to, RF energy or pulsed-field ablation (PFA) energy, including monopolar or bipolar high-voltage direct current (DC) pulses such as may be used to effect IRE, or a combination thereof. In one example, the electrodes 40 and the ablation energy generator 50 are configured to provide at least 900 volts (V) between the electrodes 40 to ablate tissue with IRE.

[0024] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheters, electrophysiological equipment, power sources, a workstation 55, and other such computational or medical equipment for controlling the operation of the system 10. The electrophysiological equipment of the system 10 may include, for example, a number of catheters, localization pads 25, body surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 includes processing capabilities for performing real-time calculations of catheter locations and for performing ECG calculations.

[0025] The workstation 55 includes a processor unit having memory, memory or storage loaded with appropriate operating software, and user interface functionality. The workstation 55 can be configured to provide multiple functions, optionally including: (1) modeling the endocardial anatomical structures in 3D and rendering the model or anatomical map 20 for display on the display device 27, (2) displaying on the display device 27 activation sequences (or other data) compiled from the recorded electrograms 21 with representative visual indicia or images superimposed on the rendered anatomical map 20, (3) displaying real-time locations and orientations of multiple catheters within the heart chambers, and (4) displaying on the display device 27 sites of interest, such as where ablation energy has been applied.

[0026] The system 10 may be configured to facilitate image-guided surgery (IGS). The IGS system may enable a physician to visually track the position of the catheter 14 within the patient 23 in real time in relation to images of anatomy (e.g., the heart 12) within the patient 23.

[0027] One commercially available product embodying each element of system 10 is available as the CARTO™ 3 system, commercially available from Biosense Webster, Inc., 31A Technology Drive, Irvine, Calif., 92618.

[0028] FIG. 2 is a diagram of the distal portion 28 of the catheter 14. The shaft 16 is aligned along a longitudinal axis AA. A spine 42 extends from the distal end of the shaft 16 and provides structural support for the basket assembly 36. The spine 42 is configured to align with the longitudinal axis AA when the distal portion 28 is delivered through the vasculature (e.g., through a sheath) to a target treatment site, and the spine 42 is configured to expand away from the longitudinal axis AA to form a resilient basket. Each spine 42 may include a resilient strut or frame formed of a flexible, resilient material, preferably a shape memory alloy such as nickel-titanium, also known as Nitinol. Each spine 42 may further include an insulating jacket covering each strut or frame to electrically insulate the electrodes 40 from the underlying struts or frame. The insulating jacket may include one or more lumens through which electrical signal conductors may extend to provide electrical contact to the electrodes 40 and communicate with the PIU 30 (FIG. 1).

[0029] The localization element 68 is coupled to the distal end of the shaft 42. The localization element 68 is configured to move relative to the transmit coil 64 in response to a force applied to the basket assembly 36. Because the localization element 68 does not require an electrical signal conductor (e.g., a wire or flex circuit trace) to transmit a signal to the PIU 30 (FIG. 1), the electrical signal conductor does not need to extend beyond the distal-most electrode 40 of the spine. Thus, the basket assembly 36 can be made to respond more symmetrically to external forces applied to the basket assembly 36 because, unlike a spine that lacks an electrical signal conductor distal to the electrode, the basket assembly 36 does not have an electrical signal conductor to the localization element 68 that would affect the elasticity of the spine. Furthermore, because the localization element 68 does not require an electrical signal conductor, there is no possibility of breakage of such an electrical signal conductor due to bending of the basket assembly.

[0030] The localization element 68 may include a conductive non-ferromagnetic material. The localization element 68 may include a diamagnetic or paramagnetic material. The localization element 68 is further biocompatible. Aluminum and stainless steel are two examples of conductive non-ferromagnetic materials that have high electrical conductivity and are suitable materials for the localization element 68. Iron, cobalt, and nickel are ferromagnetic and therefore not suitable. Examples of non-ferromagnetic metals also include gold, silver, copper, titanium, bismuth, lithium, lead, brass, and bronze, but these are not necessarily suitable if they are not biocompatible or lack sufficient electrical conductivity.

[0031] The coil assembly 60 is disposed within the shaft 16 near the distal end of the shaft 16. Because the diameter of the spine 42 is smaller than the shaft 16, the windings and electrical signal conductors of the coil assembly 60 can generally be larger than the inductive coils and electrical signal conductors of the basket assembly 36. Furthermore, because the shaft 16 is subject to less mechanical deformation during treatment compared to the basket assembly 36, the inductive coils and electrical signal conductors within the shaft 16 generally experience less mechanical stress and are therefore generally less susceptible to failure compared to the shaft's inductive coils and electrical signal conductors.

[0032] The catheter 14 can be further modified to include suitable features of other basket catheter designs, such as those disclosed in U.S. Patent Application Publication Nos. 2021 / 0307815, 2022 / 0071693, 2022 / 0071695, 2022 / 0071696, 2022 / 0087734, 2022 / 0087735, 2022 / 0193370, 2022 / 0361942, 2023 / 0015298, 2023 / 0075838, 2023 / 0112251, and 2023 / 0138104. No. 63 / 507,164, each of which is incorporated herein by reference and is attached as an appendix to the priority US Provisional Patent Application No. 63 / 507,164.

[0033] 1 and 2 collectively, the system 10 may be further configured to sense a deflection of the basket assembly 36. The coil assembly 60 may transmit a first alternating magnetic field to the localization element 68, which induces eddy currents in the localization element 68 to generate a second magnetic field, which is sensed by the coil assembly 60. The coil assembly 60 may be in electronic communication with a computing module of the system 10, which includes a signal processor having a processor and a non-transitory computer-readable medium having instructions that, when executed by the processor, cause the processor to determine a position of the localization element 68 relative to the coil assembly 60 based at least in part on signals and / or data from the coil assembly 60. The computing module may further include a signal generator configured to provide an output signal to the coil assembly 60 to generate the first alternating magnetic field. The computing module may be included in the PIU 30, the workstation 55, or may be located between the PIU 30 and the workstation 55, or may be located between the illustrated elements of the system 10 and an external computing device or system (e.g., a network / cloud computing device or system). Preferably, the PIU 30 includes a signal generator and a signal processor.

[0034] The signal processor may be further configured to determine a direction and magnitude of a force applied to the spine 42 of the basket assembly 36 based at least in part on the comparison of the output signal to the input signal. The signal processor may be further configured to determine a deformed shape of the spine 42 of the basket assembly 36 based at least in part on the comparison of the output signal to the input signal. The system 10 may further include a visualization module configured to graphically render the deformed shape for display on a display device (e.g., display 27). The visualization module may be further configured to graphically render the deformed shape in relation to an anatomical map (e.g., of the heart 12). The visualization module may include a processor and a non-transitory computer-readable medium having instructions that, when executed by the processor, cause the processor to graphically render the deformed shape. The visualization module may be included in the PIU 30, the workstation 55, or may be located between the PIU 30 and the workstation 55, or may be located between the illustrated elements of the system 10 and an external computing device or system (e.g., a network / cloud computing device or system). Preferably, the PIU 30 includes a visualization module.

[0035] 3 is a diagram of a coil assembly 60 and a localization element 68 of the catheter 14. The coil assembly 60 includes a transmit coil 64 and receive coils 61, 62, 63. The coil assembly 60 may further include a magnetic-based position sensor 66 (also referred to herein as a three-axis sensor) disposed within the shaft 16 and configured to output a signal indicative of a position and orientation of the three-axis sensor 66 relative to an externally generated magnetic field from the medical probe. At least a portion of the three-axis sensor 66 may be surrounded by the transmit coil 64.

[0036] The transmit coil 64 is disposed within the shaft 16 and aligned along the longitudinal axis AA and configured to generate a first alternating magnetic field. The localization element 68 is coupled to a distal end of the shaft 42. The localization element 68 is configured to move relative to the transmit coil 64 in response to a force exerted on the basket assembly 36. The localization element 68 is configured to generate a second alternating magnetic field based at least in part on the first alternating magnetic field and in part on a position of the localization element 68 relative to the transmit coil 64.

[0037] The transmitting coil 64 is preferably coaxial with the longitudinal axis AA. The localization element 68 is preferably centered on the longitudinal axis and has a surface that is orthogonal to the longitudinal axis AA and faces proximally toward the coil assembly 60 when the basket assembly 36 is in the extended basket configuration in free space (i.e., when no external force is applied to the basket assembly 36). The localization element 68 is preferably disk or ring shaped. The transmitting coil 64 and the localization element 68 are preferably coaxial when the basket assembly 36 is in the extended basket configuration in free space. The transmitting coil 64 is spaced from the localization element 68 by a predetermined distance D1 when the basket assembly 36 is in the extended basket configuration in free space.

[0038] The receive coils 61, 62, 63 are disposed within the shaft 16 and are each configured to output a respective electrical signal based at least in part on the overlap of the first and second alternating magnetic fields. The receive coils 61, 62, 63 may each be aligned along a longitudinal axis AA. The receive coils 61, 62, 63 may each be surrounded by a transmit coil 64.

[0039] 4 is a diagram of a transmit coil 64 inducing a first alternating magnetic field 72 which induces eddy currents 73 on the locating element 68, thereby inducing a second alternating magnetic field 74. The second alternating magnetic field 74 opposes the first alternating magnetic field 72, such that a receive coil closer to or more aligned with the second alternating magnetic field 74 will experience a smaller magnitude resultant magnetic field from the first and second alternating magnetic fields compared to a receive coil further from or less aligned with the second alternating magnetic field 74.

[0040] It should be noted that the first and second magnetic fields may be distinguishable from the magnetic field generated by a magnetic coil 32 external to the patient 23 configured to generate a magnetic field within a predetermined workspace and sensed by the magnetic-based position sensor 66. For example, the magnetic field generated by the magnetic coil 32 external to the patient 23 may have a different frequency than the frequencies of the first and second alternating magnetic fields. Because the second magnetic field is generated based on the first alternating magnetic field, the first and second alternating magnetic fields do not need to be distinguishable from each other.

[0041] 5A illustrates the basket assembly 36 deforming in response to a force F1 in the x-direction. The center of the localization element 68 is shifted in the x-direction from the longitudinal axis AA by a distance X1. In this example, the transmit coil 64 remains spaced apart from the localization element 68 by or approximately the predetermined distance D1 (FIG. 3).

[0042] FIG. 5B illustrates the localization element 68 and the receiving coils 61, 62, 63 of the catheter 14 of FIG. 5A. Each receiving coil 61, 62, 63 is aligned along a longitudinal axis AA and has a respective axis A-1, A-2, A-3 spaced apart from the longitudinal axis AA. The axes A-1, A-2, A-3 of the receiving coils 61, 62, 63 are preferably evenly distributed around the longitudinal axis AA. In the illustration, movement of the localization element 68 in the x-direction moves the localization element 68 into alignment with the axis A-2 of one of the receiving coils 62, while moving the localization element 68 away from the axes A-1, A-3 of the other receiving coils 61, 63. Thus, the second alternating magnetic field 74 (FIG. 4) interacts more with the coaxial receiving coil 62 than with the other receiving coils 61, 63. The second alternating magnetic field 74 opposes the first alternating magnetic field, such that the aligned receive coil 62 experiences a smaller magnitude resultant magnetic field from the first and second alternating magnetic fields compared to the other receive coils 61, 63. Thus, the system 10 can be configured to detect deflection of the basket assembly from the longitudinal axis AA based on the difference in signal magnitudes between the three receive coils 61, 62, 63.

[0043] FIG. 6 illustrates the deformation of the basket assembly 36 in response to a force F2 in the z-direction. The localization element 68 is moved proximally by a distance Z1 due to the force F2. Thus, the distance between the localization element 68 and the coil assembly 60 may be reduced by the distance Z1 from the predetermined distance D1 (FIG. 3). Due to this movement, the second alternating magnetic field 74 (FIG. 4) is received more strongly by the receiving coils 61, 62, 63 of the coil assembly 60, thereby reducing the magnitude of overlap of the first and second alternating magnetic fields. Because the localization element 68 remains aligned with the longitudinal axis AA, the reduction in the magnitude of overlap of the first and second alternating magnetic fields affects the receiving coils 61, 62, 63 equally. Thus, the system 10 can be configured to detect compression of the basket assembly along the longitudinal axis AA based on a change in the magnitude of the signals on the three receiving coils 61, 62, 63 from a predetermined magnitude measured when the basket assembly 36 is not deformed by a force.

[0044] 7 is a flow diagram illustrating a method 100 for determining a position of an electrically conductive, non-ferromagnetic element coupled to a distal end of a basket assembly. The electrically conductive, non-ferromagnetic element may be configured similarly to the locating element 68, alternatives thereof, or variations thereof, as will be appreciated by those skilled in the art. The method 100 may be included as instructions on a non-transitory computer readable memory that may be coupled to one or more processors of the system 10 (or alternative systems as will be appreciated by those skilled in the art), however, the system 10 is configured to perform the steps of the method 100 when the instructions of the method 100 are executed by the one or more processors.

[0045] In step 102, a first alternating magnetic field may be generated from a transmit coil disposed within the shaft of a multi-electrode basket catheter. The multi-electrode basket catheter may be configured similar to the electrodes 14 illustrated herein, variations thereof, and alternatives thereof, as will be understood by one of ordinary skill in the art. The transmit coil may be configured similar to the transmit coil 64 disclosed herein, variations thereof, and alternatives thereof, as will be understood by one of ordinary skill in the art. The first alternating magnetic field may be generated by the PIU 30, other components of the system 10 illustrated herein, variations thereof, and alternatives thereof, as will be understood by one of ordinary skill in the art.

[0046] In step 104, eddy currents may be induced on an electrically conductive, non-ferromagnetic element coupled to a distal spine end of a basket assembly of a multi-electrode basket catheter.

[0047] At step 106, respective electrical signals may be induced in a plurality of receive coils disposed within the shaft of the multi-electrode basket catheter, the respective electrical signals being based at least in part on the overlap of the first alternating magnetic field and the second alternating magnetic field generated by the eddy currents.

[0048] In step 108, the positions of the conductive non-ferromagnetic elements may be determined based at least in part on the respective electrical signals.

[0049] The following clauses list non-limiting embodiments of the present disclosure.

[0050] Clause 1. A medical probe comprising: a shaft extending along a longitudinal axis; a plurality of spines extending from a distal end of the shaft and configured to expand away from the longitudinal axis to form a resilient basket; one or more electrodes coupled to each spine of the plurality of spines; a transmit coil disposed within the shaft and aligned along the longitudinal axis and configured to generate a first alternating magnetic field; a localization element coupled to a distal end of the spine and configured to move relative to the transmit coil in response to a force exerted on the resilient basket, the localization element configured to generate a second alternating magnetic field based at least in part on the first alternating magnetic field and in part on a position of the localization element relative to the transmit coil; and a plurality of receive coils disposed within the shaft, the plurality of receive coils configured to output respective electrical signals based at least in part on an overlap of the first alternating magnetic field and the second alternating magnetic field.

[0051] Clause 2. The medical probe of clause 1, wherein the location element comprises a conductive non-ferromagnetic material.

[0052] Clause 3. The medical probe of clause 1 or 2, wherein the locating element comprises aluminum.

[0053] Clause 4. A medical probe as described in any one of clauses 1 to 3, wherein the transmitting coil and the localization element are configured such that a first alternating magnetic field induces eddy currents in the localization element, the eddy currents generating a second alternating magnetic field.

[0054] Clause 5. A medical probe as described in any one of clauses 1 to 4, wherein each of the multiple receive coils is aligned along the longitudinal axis.

[0055] Clause 6. A medical probe according to any one of clauses 1 to 5, wherein the plurality of receiving coils includes three receiving coils arranged symmetrically about the longitudinal axis.

[0056] Clause 7. A medical probe according to any one of clauses 1 to 6, wherein at least a portion of the multiple receiving coils are surrounded by the transmitting coil.

[0057] Clause 8. A medical probe as described in any one of clauses 1 to 7, further comprising a three-axis sensor disposed within the shaft, the three-axis sensor configured to output a signal indicative of the position and orientation of the three-axis sensor relative to a magnetic field generated externally from the medical probe.

[0058] Clause 9. A medical probe as described in clause 8, wherein at least a portion of the three-axis sensor is surrounded by a transmitting coil.

[0059] Clause 10. A medical probe as described in any one of clauses 1 to 9, wherein the shaft has a proximal portion and a distal portion and is configured to be manipulated at the proximal portion to position the distal portion within the patient's heart.

[0060] Clause 11. A medical probe as described in any one of clauses 1 to 10, wherein one or more electrodes are configured to sense intracardiac electrogram signals.

[0061] Clause 12. A medical probe as described in any one of clauses 1 to 11, wherein one or more electrodes are configured to provide an RF signal to ablate tissue.

[0062] Clause 13. A medical probe as described in any one of clauses 1 to 12, wherein one or more electrodes are configured to provide at least 900V between the electrodes to ablate tissue by irreversible electroporation.

[0063] Clause 14. A medical system comprising: a signal generator configured to provide an output signal to a transmit coil disposed within a shaft of a medical probe; and a signal processor configured to receive an input signal from a receive coil disposed within a shaft of a multi-electrode basket catheter; and determine a position of a conductive non-ferromagnetic element coupled to a distal end of a spine of the multi-electrode basket catheter based at least in part on a comparison of the output signal with a plurality of input signals.

[0064] Clause 15. The medical system of clause 14, wherein the multi-electrode basket catheter is configured such that the output signal generates a first alternating magnetic field by a transmitting coil, the first alternating magnetic field induces eddy currents in the conductive non-ferromagnetic element, the eddy currents generate a second alternating magnetic field, and the overlap of the first alternating magnetic field and the second alternating magnetic field affects the multiple input signals.

[0065] Clause 16. A medical system as described in clause 14 or 15, wherein the signal processor is further configured to determine a direction and magnitude of a force applied to the spine of the multi-electrode basket catheter based at least in part on a comparison of the output signal with a plurality of input signals.

[0066] Clause 17. A medical system as described in any one of clauses 14 to 16, wherein the signal processor is further configured to determine a deformed shape of the spine of the multi-electrode basket catheter based at least in part on a comparison of the output signal with a plurality of input signals.

[0067] Clause 18. The medical system of clause 17, further comprising a visualization module configured to graphically render the deformed shape for display on a display device.

[0068] Clause 19. The medical system of clause 18, wherein the visualization module is further configured to graphically render the deformed shape in relation to an anatomical map.

[0069] Clause 20. The medical system of any one of clauses 14 to 19, further comprising an intracardiac electrogram (IEGM) sensor configured to receive IEGM signals from an electrode of the multi-electrode basket catheter.

[0070] Clause 21. The medical system of any one of clauses 14 to 20, further comprising a radio frequency (RF) ablation energy generator configured to provide a radio frequency (RF) signal to an electrode of the multi-electrode basket catheter to perform radio frequency (RF) ablation of tissue.

[0071] Clause 22. A medical system described in any one of clauses 14 to 21, further comprising a pulsed field ablation (PFA) energy generator configured to provide a pulse signal to an electrode of the multi-electrode basket catheter to perform ablation by irreversible electroporation.

[0072] Clause 23. A medical system described in any one of clauses 14 to 22, further comprising a magnetic field generator configured to generate a magnetic field within an external, predetermined working space, and a magnetic tracking signal processor configured to receive a navigation signal from a three-axis sensor disposed within the shaft of the multi-electrode basket catheter and determine a position and orientation of the three-axis sensor within the predetermined working space based at least in part on the navigation signal.

[0073] Clause 24. A method comprising: generating a first alternating magnetic field from a transmitting coil disposed within a shaft of a multi-electrode basket catheter; inducing eddy currents on a conductive non-ferromagnetic element coupled to a distal spine end of a basket assembly of the multi-electrode basket catheter; inducing respective electrical signals in a plurality of receiving coils disposed within the shaft of the multi-electrode basket catheter, the respective electrical signals being based at least in part on an overlap of the first and second alternating magnetic fields generated by the eddy currents; and determining a position of the conductive non-ferromagnetic element based at least in part on the respective electrical signals.

[0074] Clause 25. The method of clause 24, further comprising determining a direction and magnitude of a force applied to the basket assembly based at least in part on the respective electrical signals.

[0075] Clause 26. The method of clause 24 or 25, further comprising determining a deformed shape of the basket assembly based at least in part on the respective electrical signals.

[0076] Clause 27. The method of clause 26, further comprising graphically rendering the deformed shape.

[0077] Clause 28. The method of clause 26, further comprising graphically rendering the deformed shape in relation to the anatomical map.

[0078] Clause 29. The method of any one of clauses 24 to 28, further comprising receiving an intracardiac electrogram signal from an electrode of a multi-electrode basket catheter.

[0079] Clause 30. The method of any one of clauses 24 to 29, further comprising generating radiofrequency ablation energy at an electrode of a multi-electrode basket catheter.

[0080] Clause 31. The method of any one of clauses 24 to 29, further comprising generating pulsed field ablation energy at an electrode of a multi-electrode basket catheter.

[0081] Clause 32. The method of any one of clauses 24 to 31, further comprising determining a position and orientation of a three-axis sensor disposed within the shaft of the multi-electrode basket catheter.

[0082] Although exemplary embodiments of the subject matter encompassed by the present invention have been shown and described, further adaptations of the methods and systems described herein can be achieved by appropriate modifications without departing from the scope of the claims. Moreover, where the above methods and steps show certain events occurring in a particular order, it is intended that the specific steps need not be performed in the order described, but rather in any order as long as the steps enable the embodiments to function for their intended purpose. Thus, to the extent there are variations of the invention that are within the spirit of the disclosure or equivalent to the invention found in the claims, this patent is intended to cover those variations as well. Some such modifications should be apparent to those skilled in the art. For example, the above examples, embodiments, geometries, materials, dimensions, proportions, steps, etc. are exemplary. Thus, the claims should not be limited to the specific details of structure and operation set forth in the specification and drawings.

[0083] [Embodiment] (1) A medical probe comprising: a shaft extending along a longitudinal axis; a plurality of spines extending from a distal end of the shaft and configured to expand away from the longitudinal axis to form a resilient basket; one or more electrodes coupled to each spine of the plurality of spines; a transmit coil disposed within the shaft and aligned along the longitudinal axis and configured to generate a first alternating magnetic field; a localization element coupled to a distal end of the spine and configured to move relative to the transmit coil in response to a force on the elastic basket, the localization element configured to generate a second alternating magnetic field based at least in part on the first alternating magnetic field and in part on a position of the localization element relative to the transmit coil; a plurality of receive coils disposed within the shaft, the receive coils configured to output respective electrical signals based at least in part on an overlap of the first alternating magnetic field and the second alternating magnetic field; A medical probe comprising: (2) A medical probe as described in embodiment 1, wherein the location element comprises a conductive non-ferromagnetic material. (3) A medical probe as described in embodiment 1, wherein the transmitting coil and the localization element are configured such that the first alternating magnetic field induces eddy currents in the localization element, and the eddy currents generate the second alternating magnetic field. (4) A medical probe as described in embodiment 1, wherein each of the multiple receive coils is aligned along the longitudinal axis. (5) A medical probe as described in embodiment 1, wherein the plurality of receiving coils includes three receiving coils arranged symmetrically about the longitudinal axis, and at least a portion of the plurality of receiving coils is surrounded by the transmitting coil.

[0084] (6) The medical probe of claim 1, further comprising a three-axis sensor disposed within the shaft, the three-axis sensor configured to output a signal indicative of a position and orientation of the three-axis sensor relative to a magnetic field generated externally from the medical probe. (7) The medical probe of embodiment 1, wherein the one or more electrodes are configured to sense intracardiac electrogram signals, provide radiofrequency signals to ablate tissue, and / or provide at least 900V between the electrodes to ablate tissue by irreversible electroporation. (8) A medical system comprising: a signal generator configured to provide an output signal to a transmit coil disposed within a shaft of the medical probe; 1. A signal processor comprising: receiving a plurality of input signals from a plurality of receive coils disposed within a shaft of a multi-electrode basket catheter; determining a position of an electrically conductive non-ferromagnetic element coupled to a distal end of a spine of the multi-electrode basket catheter based at least in part on a comparison of the output signal to the plurality of input signals; a signal processor configured to: A medical system comprising: (9) The medical system of embodiment 8, wherein the multi-electrode basket catheter is configured such that the output signal causes the transmitting coil to generate a first alternating magnetic field, the first alternating magnetic field induces eddy currents in the conductive non-ferromagnetic element, the eddy currents generate a second alternating magnetic field, and an overlap of the first alternating magnetic field and the second alternating magnetic field affects the multiple input signals. (10) The signal processor, 9. The medical system of claim 8, further configured to determine a direction and magnitude of a force applied to a spine of the multi-electrode basket catheter based at least in part on a comparison of the output signal with the plurality of input signals.

[0085] (11) The signal processor, 9. The medical system of claim 8, further configured to determine a deformed shape of the spine of the multi-electrode basket catheter based at least in part on a comparison of the output signal with the plurality of input signals. (12) The medical system of embodiment 11, further comprising a visualization module configured to graphically render the deformed shape for display on a display device and to graphically render the deformed shape in relation to an anatomical map. (13) The medical system of embodiment 8, further comprising an intracardiac electrogram (IEGM) sensor configured to receive an IEGM signal from an electrode of the multi-electrode basket catheter. (14) The medical system of embodiment 8, further comprising an ablation energy generator configured to provide RF signals and / or pulse signals to electrodes of the multi-electrode basket catheter to perform RF ablation and / or irreversible electroporation of tissue. (15) generating a first alternating magnetic field from a transmitting coil disposed in a shaft of the multi-electrode basket catheter; inducing eddy currents on an electrically conductive non-ferromagnetic element coupled to a distal spine end of a basket assembly of the multi-electrode basket catheter; inducing respective electrical signals in a plurality of receive coils disposed within the shaft of the multi-electrode basket catheter, the respective electrical signals being based at least in part on a superposition of the first alternating magnetic field and a second alternating magnetic field generated by the eddy currents; determining a position of the conductive non-ferromagnetic elements based at least in part on the respective electrical signals; A method comprising:

[0086] (16) The method of embodiment 15, further comprising determining a direction and magnitude of a force applied to the basket assembly based at least in part on the respective electrical signals. (17) The method of claim 15, further comprising determining a deformed shape of the basket assembly based at least in part on the respective electrical signals. (18) The method of embodiment 17, further comprising graphically rendering the deformed shape in relation to an anatomical map. (19) The method of embodiment 15, further comprising receiving an intracardiac electrogram signal from an electrode of the multi-electrode basket catheter. (20) The method of embodiment 15, further comprising generating radiofrequency ablation energy at an electrode of the multi-electrode basket catheter and / or generating pulsed field ablation energy at an electrode of the multi-electrode basket catheter.

Claims

1. 1. A medical probe, comprising: a shaft extending along a longitudinal axis; a plurality of spines extending from a distal end of the shaft and configured to expand away from the longitudinal axis to form a resilient basket; one or more electrodes coupled to each spine of the plurality of spines; a transmit coil disposed within the shaft and aligned along the longitudinal axis and configured to generate a first alternating magnetic field; a localization element coupled to a distal end of the spine and configured to move relative to the transmit coil in response to a force on the elastic basket, the localization element configured to generate a second alternating magnetic field based at least in part on the first alternating magnetic field and in part on a position of the localization element relative to the transmit coil; a plurality of receive coils disposed within the shaft, the receive coils configured to output respective electrical signals based at least in part on an overlap of the first alternating magnetic field and the second alternating magnetic field; A medical probe comprising:

2. The medical probe of claim 1 , wherein the localization element comprises an electrically conductive non-ferromagnetic material.

3. 2. The medical probe of claim 1, wherein the transmit coil and the localization element are configured such that the first alternating magnetic field induces eddy currents in the localization element, the eddy currents generating the second alternating magnetic field.

4. The medical probe of claim 1 , wherein each of the plurality of receive coils is aligned along the longitudinal axis.

5. 2. The medical probe of claim 1, wherein the plurality of receive coils includes three receive coils arranged symmetrically about the longitudinal axis, at least a portion of the plurality of receive coils being surrounded by the transmit coil.

6. 10. The medical probe of claim 1, further comprising a three-axis sensor disposed within the shaft, the three-axis sensor configured to output a signal indicative of a position and orientation of the three-axis sensor relative to a magnetic field generated externally from the medical probe.

7. 10. The medical probe of claim 1, wherein the one or more electrodes are configured to sense intracardiac electrogram signals, provide radiofrequency signals to ablate tissue, and / or provide at least 900V between electrodes to ablate tissue with irreversible electroporation.

8. 1. A medical system comprising: a signal generator configured to provide an output signal to a transmit coil disposed within a shaft of the medical probe; 1. A signal processor comprising: receiving a plurality of input signals from a plurality of receive coils disposed within a shaft of a multi-electrode basket catheter; determining a position of an electrically conductive non-ferromagnetic element coupled to a distal end of a spine of the multi-electrode basket catheter based at least in part on a comparison of the output signal to the plurality of input signals; a signal processor configured to: A medical system comprising:

9. 9. The medical system of claim 8, wherein the multi-electrode basket catheter is configured such that the output signal causes the transmit coil to generate a first alternating magnetic field, the first alternating magnetic field induces eddy currents in the conductive non-ferromagnetic element, the eddy currents generate a second alternating magnetic field, and an overlap of the first and second alternating magnetic fields affects the multiple input signals.

10. The signal processor, 10. The medical system of claim 8, further configured to determine a direction and magnitude of a force applied to a spine of the multi-electrode basket catheter based at least in part on a comparison of the output signal to the plurality of input signals.

11. The signal processor, 10. The medical system of claim 8, further configured to determine a deformed shape of the spine of the multi-electrode basket catheter based at least in part on a comparison of the output signal to the plurality of input signals.

12. 12. The medical system of claim 11, further comprising a visualization module configured to graphically render the deformed shape for display on a display device and to graphically render the deformed shape in relation to an anatomical map.

13. 10. The medical system of claim 8, further comprising an intracardiac electrogram (IEGM) sensor configured to receive IEGM signals from electrodes of the multi-electrode basket catheter.

14. 10. The medical system of claim 8, further comprising an ablation energy generator configured to provide RF and / or pulsed signals to electrodes of the multi-electrode basket catheter to perform RF ablation and / or irreversible electroporation of tissue.

15. generating a first alternating magnetic field from a transmitting coil disposed within a shaft of a multi-electrode basket catheter; inducing eddy currents on an electrically conductive non-ferromagnetic element coupled to a distal spine end of a basket assembly of the multi-electrode basket catheter; inducing respective electrical signals in a plurality of receive coils disposed within the shaft of the multi-electrode basket catheter, the respective electrical signals being based at least in part on an overlap of the first alternating magnetic field and a second alternating magnetic field generated by the eddy currents; determining a position of the conductive non-ferromagnetic elements based at least in part on the respective electrical signals; A method comprising:

16. The method of claim 15, further comprising determining a direction and magnitude of a force applied to the basket assembly based at least in part on the respective electrical signals.

17. The method of claim 15, further comprising determining a deformed shape of the basket assembly based at least in part on the respective electrical signals.

18. The method of claim 17 , further comprising graphically rendering the deformed shape in relation to an anatomical map.

19. 16. The method of claim 15, further comprising receiving intracardiac electrogram signals from electrodes of the multi-electrode basket catheter.

20. 16. The method of claim 15, further comprising generating radio frequency ablation energy at an electrode of the multi-electrode basket catheter and / or generating pulsed field ablation energy at an electrode of the multi-electrode basket catheter.

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