Basket catheter with vortex dependent deformation sensor

Abstract

A basket catheter and system configured to determine a force on a basket assembly of the basket catheter and / or to determine a deformation of the basket assembly by using a sensor assembly in the basket catheter, the sensor assembly includes a transmit coil and a plurality of receive coils in the catheter shaft and an electrically conductive plate, disc, or ring at the distal end of the basket assembly. The system is configured to provide a signal to the transmit coil to generate a first magnetic field, which in turn induces an eddy current in the conductive plate, disc or ring, which in turn generates a second magnetic field. The receiving coil detects a superposition of the first magnetic field and the second magnetic field, and the system determines the force and / or deformation based at least in part on a signal from the receiving coil.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application No. 63 / 507,164, attorney docket No. BIO6818USPSP1-253757.000356, previously filed on June 9, 2023, which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present invention relates generally to medical devices, and in particular to multi-electrode basket catheters. Background Art

[0004] 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 an irregular heartbeat. Areas of cardiac tissue can be mapped by a catheter to identify abnormal electrical signals. Electrophysiological (EP) mapping may include using sensing electrodes configured to monitor electrical signals within the cardiovascular system to precisely determine the location of abnormally conductive tissue sites that cause arrhythmias. An example of an EP mapping system is described in U.S. Patent No. 5,738,096, which is incorporated herein by reference.

[0005] By applying energy via a catheter to selectively ablate cardiac tissue, it is sometimes possible to stop or alter the propagation of unwanted electrical signals from one part of the heart to another. The ablation may be performed using the same or different catheters. A catheter configured for mapping and / or ablation typically includes at least one electrode and / or a multi-electrode end effector coupled to a distal end of a shaft of the catheter.

[0006] Catheter ablation procedures can be performed using an image-guided surgery (IGS) system. An IGS system can enable a physician to visually track the position of a catheter in a patient relative to an image of the patient's anatomy in real time. Some systems can provide a combination of EP mapping and IGS functionality, including the CARTO system.

[0007] Many current ablation methods utilize radiofrequency (RF) electrical energy to heat tissue. Cryoablation and irreversible electroporation (IRE) are alternative ablation techniques. Cryoablation is a process that uses extremely cold temperatures to destroy tissue. Both RF and IRE utilize electrical signals applied to tissue. However, IRE is considered non-thermal because IRE does not rely on heating to damage tissue; rather, the electrical signal applied during IRE causes irreversible permeabilization of cell membranes.

[0008] A given catheter used for an AF procedure may be configured for mapping, ablation, or both. The distal portion of the catheter is configured to pass through a blood vessel to be positioned in the heart and / or in an adjacent blood vessel. In addition to catheters specifically configured for cryoablation, the distal portion of the catheter includes one or more electrodes that are configured to monitor electrical signals within the cardiovascular system and / or are configured to ablate via RF and / or IRE. The distal portion of the catheter may have a variety of configurations. A basket catheter is a type that has spines that extend along a longitudinal axis when contracted for delivery through the vascular system and 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

[0009] Examples provided herein generally include a basket catheter and an IGS system configured to determine forces on a basket assembly of a basket catheter and / or to determine deformation of the basket assembly by using a sensor assembly in the basket catheter, the sensor assembly comprising a transmitting coil and a plurality of receiving coils in the catheter shaft and a conductive plate, disk or ring at the 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 in turn induces eddy currents in the conductive plate, disk or ring, which in turn generates a second magnetic field. The receiving coil detects the superposition of the first magnetic field and the second magnetic field and sends a signal to the IGS system, which determines the force and / or deformation based at least in part on the signal from the receiving coil.

[0010] An exemplary medical probe includes a shaft, a spine, an electrode, a transmitting coil, a positioning element, and a receiving coil. The shaft extends along a longitudinal axis. The spine extends from the distal end of the shaft and is configured to expand away from the longitudinal axis to form an elastic basket. The electrode is coupled to each spine. The transmitting coil is disposed in the shaft, aligned along the longitudinal axis and configured to generate a first alternating magnetic field. The positioning element is coupled to the distal end of the spine. The positioning element is configured to move relative to the transmitting coil in response to a force on the elastic basket. The positioning 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 the position of the positioning element relative to the transmitting coil. The receiving coils are disposed in the shaft and are each configured to output a corresponding electrical signal based at least in part on the superposition of the first alternating magnetic field and the second alternating magnetic field.

[0011] 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 transmitting coil disposed in a shaft of a medical probe. The signal processor may be configured to receive a plurality of input signals from a plurality of receiving coils disposed in 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 signals with the input signals.

[0012] An exemplary method may include one or more of the following steps performed in various orders and with interleaved steps as understood by those skilled in the art. The method may include generating a first alternating magnetic field from a transmitting coil disposed in a shaft of a multi-electrode basket catheter; inducing eddy currents on a conductive non-ferromagnetic element at a distal spine end of a basket assembly coupled to the multi-electrode basket catheter; inducing a corresponding electrical signal in a receiving coil disposed in the shaft of the multi-electrode basket catheter, such that the corresponding electrical signal is 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; and determining a position of the conductive non-ferromagnetic element based at least in part on the corresponding electrical signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Although claims are provided after the specification which particularly point out and distinctly claim the subject matter described herein, it is believed that the subject matter will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals represent the same elements. The accompanying drawings depict one or more specific implementations of the present device by way of example only and not by way of limitation.

[0014] Figure 1 is a diagram of an exemplary catheter-based electrophysiological mapping and ablation system according to aspects of the present invention.

[0015] Figure 2 is an illustration of a distal portion of an exemplary catheter according to aspects of the present invention.

[0016] Figure 3 is an illustration of a coil assembly and positioning element of a catheter according to aspects of the present invention.

[0017] Figure 4 is a diagram of a transmitting coil inducing a first alternating magnetic field according to aspects of the present invention, the first alternating magnetic field inducing eddy currents on a positioning element, thereby inducing a second alternating magnetic field.

[0018] Figure 5A is a graphical representation of deformation of a basket assembly of a catheter in accordance with aspects of the present invention in response to a force in the x-direction.

[0019] Figure 5B According to various aspects of the present invention Figure 5A Illustration of the positioning element and receiving coil of a catheter.

[0020] Figure 6 is a graphical representation of deformation of a basket assembly of a catheter in accordance with aspects of the present invention in response to a force in the z-direction.

[0021] Figure 7is an illustration of a flow chart of a method for determining a position of a conductive non-ferromagnetic element coupled to a distal end of a basket assembly according to aspects of the present invention. DETAILED DESCRIPTION

[0022] The following specific embodiments should be read in conjunction with the accompanying drawings, wherein the same elements are labeled the same in different drawings. The accompanying drawings (not necessarily drawn 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 by way of example and not by way of limitation. This description will clearly enable those skilled in the art to prepare and use the invention, and describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including the best modes currently believed to be implemented in the invention.

[0023] As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows a part or a collection of components to achieve its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of ±10% of the value of the recited value, for example, "about 90%" may refer to a range of values ​​from 81% to 99%.

[0024] In addition, as used herein, the terms "patient", "recipient", "user" and "subject" refer to any human or animal subject, and are not intended to limit the systems or methods to human use, but the use of the subject invention in human patients represents a preferred embodiment. Likewise, the term "proximal" refers to a position closer to an operator, while "distal" refers to a position farther from an operator or physician.

[0025] When used in this article, the terms "tubular" and "tube" should be understood broadly and are not limited to structures that are right cylindrical or have a completely circular cross-section or a uniform cross-section over its entire length. For example, tubular structures or systems are generally shown as substantially right cylindrical structures. However, without departing from the scope of the present invention, tubular systems may have tapered or curved outer surfaces. Tubular structures or tubes may have a hollow or solid core.

[0026] Alternative device and system features and alternative method steps are presented in the exemplary embodiments herein. As will be understood by those skilled in the relevant art and as explicitly stated herein, each given exemplary embodiment presented herein may be modified to include features and / or method steps presented with different exemplary embodiments herein, where such features and / or steps are compatible with the given examples. Such modifications and variations are intended to be included within the scope of the claims.

[0027] Figure 1is a diagram showing an exemplary catheter-based electrophysiological mapping and ablation system 10. The system 10 includes a plurality of catheters that are inserted into a chamber or vascular structure of a heart 12 by a physician 24 through the patient's vascular system via the skin. Typically, a delivery sheath catheter is inserted into the left atrium or right atrium near a desired location in the heart 12. Then, a plurality of catheters may be inserted into the delivery sheath catheter to reach the desired location. The plurality of catheters may include a catheter dedicated to sensing intracardiac electrogram (IEGM) signals, a catheter dedicated to ablation, and / or a catheter 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 for sensing IEGM signals and / or ablation of a target site in the heart 12. The catheter 14 includes a shaft 16 having a proximal portion that can be manipulated by the physician 24 outside the patient 23 (e.g., by a handle) to position the distal portion of the shaft 16 into the heart 12.

[0028] The illustrated catheter 14 is an exemplary catheter that includes one and preferably multiple electrodes 40 distributed over a plurality of ridges 42 of a basket assembly 36 and configured to sense IEGM signals and apply electrical signals for RF and / or IRE ablation. The catheter 14 may additionally include a position sensor 66 embedded in or near the distal portion 28 (e.g., embedded in the shaft 16 of the catheter 14) for tracking the position and orientation of the distal portion 28. Optionally and preferably, the position sensor 66 is a magnetically based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0029] The magnetic-based position sensor 66 can operate with a positioning pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predefined workspace. The real-time position of the distal portion 28 of the catheter 14 can be tracked based on the magnetic field generated by the positioning pad 25 and sensed by the magnetic-based position sensor 66. A navigation signal can be sent from the magnetic-based position sensor 66, which can be used by the system 10 to determine the position and orientation of the magnetic-based position sensor 66 within the predefined workspace. The details of the magnetic-based position sensing technology are described in U.S. Patents 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.

[0030] The system 10 includes one or more electrode patches 38 positioned on the patient 23 for skin contact to establish a positioning reference for the locating pad 25 and impedance-based tracking coupled to the electrodes 40 on the ridges 42 and / or to the electrodes 19 on the shaft 16 of the catheter 14 in the distal portion 28. For impedance-based tracking, current is directed to the electrodes of the distal portion 28 of the catheter 14 and sensed at the electrode skin patches 38 so that the position of each catheter electrode can be triangulated via the electrode patches 38. Details of impedance-based position 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.

[0031] Recorder 11 displays electrograms 21 captured using surface electrocardiogram (ECG) electrodes 18 and may also display IEGM signals captured using electrodes 40 of catheter 14. Recorder 11 may include pacing capabilities for pacing the cardiac rhythm and / or may be electrically connected to a separate pacemaker.

[0032] 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 unipolar or bipolar high voltage direct current (DC) pulses that may be used to achieve 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 using IRE.

[0033] The patient interface unit (PIU) 30 is an interface configured to establish electrical communications between catheters, electrophysiology equipment, power supplies, and workstations 55, as well as other such computing or medical devices used to control the operation of the system 10. The electrophysiology equipment of the system 10 may include, for example, a plurality of catheters, positioning pads 25, surface ECG electrodes 18, electrode patches 38, ablation energy generators 50, and recorders 11. Optionally and preferably, the PIU 30 includes processing capabilities for enabling real-time calculation of the position of the catheters and for performing ECG calculations.

[0034] The workstation 55 includes a memory, a processor unit with a memory or storage device loaded with appropriate operating software, and a user interface capability. The workstation 55 can be configured to provide a variety of functions, optionally including: (1) 3D modeling of the endocardial anatomy and rendering the model or anatomical map 20 for display on the display device 27; (2) displaying the activation sequence (or other data) compiled from the recorded electrogram 21 on the display device 27 as representative visual markers or images superimposed on the rendered anatomical map 20; (3) displaying the real-time position and orientation of multiple catheters within the heart chamber; and (4) displaying on the display device 27 areas of interest such as where ablation energy is applied.

[0035] System 10 may be configured to facilitate image-guided surgery (IGS). An IGS system may enable a physician to visually track the position of catheter 14 within patient 23 relative to images of anatomical structures (eg, heart 12) within patient 23 in real time.

[0036] A commercial product embodying elements of system 10 may be CARTO TM The 3 system was purchased from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618.

[0037] Figure 2 is an illustration of the distal portion 28 of the catheter 14. The shaft 16 is aligned along the longitudinal axis AA. A ridge 42 extends from the distal end of the shaft 16 and provides structural support for the basket assembly 36. The ridge 42 is configured to be aligned with the longitudinal axis AA when the distal portion 28 is delivered to the target treatment site through the vasculature (e.g., via a sheath), and the ridge 42 is configured to expand away from the longitudinal axis AA to form a resilient basket. Each ridge 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 ridge 42 may also include an insulating jacket on each strut or frame to electrically isolate the electrode 40 from the underlying strut or frame. The insulating jacket may include one or more lumens through which an electrical signal conductor may extend to provide electrical contact with the electrode 40 to communicate with the PIU 30 ( Figure 1 ) communication.

[0038] The positioning element 68 is coupled to the distal end of the spine 42. The positioning element 68 is configured to move relative to the transmitting coil 64 in response to forces on the basket assembly 36. Because the positioning element 68 does not require electrical signal conductors (e.g., wires or flexible circuit traces) to transmit signals to the PIU 30 ( Figure 1), so there is no need for the electrical signal conductor to extend beyond the most distal electrode 40 of the spine. The basket assembly 36 can therefore be made more symmetrical in response to external forces applied to the basket assembly 36 because there is no electrical signal conductor to the positioning element 68 to affect the elasticity of the spine, unlike a spine without an electrical signal conductor distal to the electrode. In addition, since the positioning element 68 does not require an electrical signal conductor, there is a possibility that such an electrical signal conductor may break due to bending of the basket assembly.

[0039] The positioning element 68 may include a conductive non-ferromagnetic material. The positioning element 68 may include a diamagnetic material or a paramagnetic material. The positioning element 68 is further biocompatible. Aluminum and stainless steel are two examples of conductive non-ferromagnetic materials with high conductivity and are suitable materials for the positioning 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 are not necessarily suitable if they are not biocompatible or lack sufficient conductivity.

[0040] The coil assembly 60 is disposed in the shaft 16 near the distal end of the shaft 16. Generally, the windings and electrical signal conductors of the coil assembly 60 can be made larger than the induction coils and electrical signal conductors of the basket assembly 36 because the diameter of the spine 42 is smaller than the shaft 16. In addition, the shaft 16 experiences less mechanical deformation during treatment than the basket assembly 36, so that the induction coils and electrical signal conductors in the shaft 16 generally experience less mechanical stress and are therefore generally less susceptible to fracture than the induction coils and electrical signal conductors of the shaft.

[0041] The catheter 14 may also be modified to include compatible features of other basket catheter designs, such as those disclosed in U.S. Patent 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, each of which is incorporated herein by reference and is attached as an appendix to U.S. Provisional Patent Application No. 63 / 507,164.

[0042] Common Reference Figure 1 and Figure 2, the system 10 may also be configured to sense deflection of the basket assembly 36. The coil assembly 60 may emit a first alternating magnetic field to the positioning element 68, the first alternating magnetic field inducing eddy currents in the positioning element 68, thereby causing a second magnetic field to be generated, which is sensed by the coil assembly 60. The coil assembly 60 may be in electrical communication with a computing module of the system 10, the computing module including a signal processor having a processor and a non-transitory computer-readable medium having instructions thereon, the instructions when executed by the processor causing the processor to determine the position of the positioning element 68 relative to the coil assembly 60 based at least in part on the signal and / or data from the coil assembly 60. The computing module may also 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, included in the workstation 55, distributed between the PIU 30 and the workstation 55, distributed between the elements of the illustrated 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.

[0043] The signal processor may also be configured to determine the direction and magnitude of the force applied to the spine 42 of the basket assembly 36 based at least in part on the comparison of the output signal with the input signal. The signal processor may also be configured to determine the deformed shape of the spine 42 of the basket assembly 36 based at least in part on the comparison of the output signal with the input signal. The system 10 may also include a visualization module configured to graphically present the deformed shape for display on a display device (e.g., display 27). The visualization module may also be configured to graphically present the deformed shape relative 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 thereon that, when executed by the processor, cause the processor to graphically present the deformed shape. The visualization module may be included in the PIU 30, included in the workstation 55, distributed between the PIU 30 and the workstation 55, distributed between the elements of the illustrated system 10 and an external computing device or system (e.g., a network / cloud computing device or system). Preferably, the PIU 30 includes the visualization module.

[0044] Figure 3 1 is a diagram of a coil assembly 60 and a positioning element 68 of a catheter 14. The coil assembly 60 includes a transmitting coil 64 and receiving coils 61, 62, 63. The coil assembly 60 may also include a magnetically based position sensor 66 (also referred to herein as a three-axis sensor) disposed within the shaft 16 and configured to output a signal indicating the position and orientation of the three-axis sensor 66 relative to a magnetic field generated externally from the medical probe. At least a portion of the three-axis sensor 66 can be surrounded by the transmitting coil 64.

[0045] The transmitting coil 64 is disposed within the shaft 16, aligned along the longitudinal axis AA and configured to generate a first alternating magnetic field. A positioning element 68 is coupled to the distal end of the spine 42. The positioning element 68 is configured to move relative to the transmitting coil 64 in response to a force on the basket assembly 36. The positioning 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 the position of the positioning element 68 relative to the transmitting coil 64.

[0046] The transmitting coil 64 is preferably coaxial with the longitudinal axis AA. The positioning element 68 is preferably centered on the longitudinal axis and has a surface orthogonal to the longitudinal axis AA, and faces the coil assembly 60 proximally when the basket assembly 36 is in the expanded basket configuration in free space (i.e., no external forces applied to the basket assembly 36). The positioning element 68 is preferably disk-shaped or ring-shaped. When the basket assembly 36 is in the expanded basket configuration in free space, the transmitting coil 64 and the positioning element 68 are preferably coaxial. When the basket assembly 36 is in the expanded basket configuration in free space, the transmitting coil 64 is separated from the positioning element 68 by a predetermined distance D1.

[0047] The receiving coils 61, 62, 63 are disposed within the shaft 16 and are each configured to output a corresponding electrical signal based at least in part on the superposition of the first alternating magnetic field and the second alternating magnetic field. The receiving coils 61, 62, 63 may each be aligned along the longitudinal axis AA. The receiving coils 61, 62, 63 may each be surrounded by a transmitting coil 64.

[0048] Figure 4 is an illustration of a transmitter coil 64 inducing a first alternating magnetic field 72, which induces eddy currents 73 on a positioning element 68, thereby inducing a second alternating magnetic field 74. The second alternating magnetic field 74 is opposite to the first alternating magnetic field 72, such that a receiver coil that is closer to or more aligned with the second alternating magnetic field 74 experiences a lower magnitude composite magnetic field from the first and second alternating magnetic fields than a receiver coil that is further away from or less aligned with the second alternating magnetic field 74.

[0049] It is noted that the first magnetic field and the second magnetic field can be distinguished from the magnetic field generated by the magnetic coil 32 outside the patient 23, which is configured to generate a magnetic field in the predefined workspace and is sensed by the magnetic-based position sensor 66. For example, the magnetic field generated by the magnetic coil 32 outside the patient 23 can have a frequency different from the frequency of the first alternating magnetic field and the second alternating magnetic field. The first alternating magnetic field and the second alternating magnetic field do not have to be distinguished from each other because the second magnetic field is generated based on the first alternating magnetic field.

[0050] Figure 5Ais an illustration of the deformation of the basket assembly 36 in response to the force F1 in the x-direction. The center of the positioning element 68 is offset from the longitudinal axis AA in the x-direction by a distance X1. In this example, the transmitting coil 64 is maintained separated from the positioning element 68 by a predetermined distance D1, or approximately the predetermined distance D1 ( Figure 3 ).

[0051] Figure 5B yes Figure 5A 1 and 1 . An illustration of a positioning element 68 and receiving coils 61, 62, 63 of a catheter 14. Each receiving coil 61, 62, 63 has a respective axis A-1, A-2, A-3 that is aligned along and 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 positioning element 68 in the x-direction moves the positioning element 68 in alignment with the axis A-2 of one of the receiving coils 62, while moving the positioning element 68 away from the axes A-1, A-3 of the other receiving coils 61, 63. Thus, the second alternating magnetic field 74 ( Figure 4 ) interacts with the coaxial receiving coil 62 more than with the other receiving coils 61, 63. The second alternating magnetic field 74 is opposite to the first alternating magnetic field, so that the aligned receiving coil 62 experiences a lower magnitude composite magnetic field from the first alternating magnetic field and the second alternating magnetic field than the other receiving coils 61, 63. Therefore, the system 10 can be configured to detect deflection of the basket assembly about the longitudinal axis AA based on the difference in signal magnitude between the three receiving coils 61, 62, 63.

[0052] Figure 6 3 is a diagram of the deformation of the basket assembly 36 in response to the force F2 in the z-direction. The positioning element 68 moves proximally due to the force F2. The distance between the positioning element 68 and the coil assembly 60 can thus be changed from the predetermined distance D1 ( Figure 3 ) reduces the distance Z1. Due to this movement, the second alternating magnetic field 74 ( Figure 4 ) is more strongly received by the receiving coils 61, 62, 63 of the coil assembly 60, thereby reducing the magnitude of the superposition of the first alternating magnetic field and the second alternating magnetic field. Because the positioning element 68 remains aligned with the longitudinal axis AA, the receiving coils 61, 62, 63 equally experience the reduction in the magnitude of the superposition of the first alternating magnetic field and the second alternating magnetic field. Therefore, the system 10 can be configured to detect the compression of the basket assembly along the longitudinal axis AA based on the magnitude of the signals on the three receiving coils 61, 62, 63 from the change in the predetermined magnitude measured when the basket assembly 36 is not deformed by the force.

[0053] Figure 71 is an illustration of a flow chart of a method 100 for determining the position of a conductive non-ferromagnetic element coupled to a distal end of a basket assembly. As understood by those skilled in the relevant art, the conductive non-ferromagnetic element may be configured similar to the positioning element 68, an alternative thereof, or a variation thereof. 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 an alternative system as understood by those skilled in the relevant art), such that when the instructions of the method 100 are executed by the one or more processors, the system 10 is configured to perform the steps of the method 100.

[0054] At step 102, a first alternating magnetic field may be generated from a transmitting coil disposed in a 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 understood by those skilled in the relevant art. The transmitting coil may be configured similar to the transmitting coil 64 illustrated herein, variations thereof, and alternatives thereof, as understood by those skilled in the relevant art. As understood by those skilled in the relevant 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.

[0055] In step 104, eddy currents may be induced on an electrically conductive, non-ferromagnetic element of a distal spine end coupled to a basket assembly of a multi-electrode basket catheter.

[0056] In step 106, corresponding electrical signals may be induced in a plurality of receiving coils disposed in the shaft of the multi-electrode basket catheter, such that the corresponding electrical signals are based at least in part on a superposition of the first alternating magnetic field and a second alternating magnetic field generated by eddy currents.

[0057] In step 108 , a position of the electrically conductive non-ferromagnetic element may be determined based at least in part on the corresponding electrical signal.

[0058] The following clauses set forth non-limiting embodiments of the present disclosure:

[0059] Item 1. A medical probe comprising: a shaft extending along a longitudinal axis; a plurality of ridges extending from a distal end of the shaft and configured to expand away from the longitudinal axis to form an elastic basket; one or more electrodes coupled to each of the plurality of ridges; a transmitting coil disposed within the shaft, aligned along the longitudinal axis and configured to generate a first alternating magnetic field; a positioning element coupled to the distal end of the ridge, configured to move relative to the transmitting coil in response to a force on the elastic basket, and 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 positioning element relative to the transmitting coil; and a plurality of receiving coils disposed within the shaft and configured to output corresponding electrical signals based at least in part on a superposition of the first alternating magnetic field and the second alternating magnetic field.

[0060] Clause 2. The medical probe of clause 1, wherein the positioning element comprises an electrically conductive non-ferromagnetic material.

[0061] Clause 3. The medical probe of Clause 1 or Clause 2, wherein the positioning element comprises aluminum.

[0062] Clause 4. The medical probe according to any one of clauses 1 to 3, wherein the transmitting coil and the positioning element are configured such that the first alternating magnetic field induces eddy currents in the positioning element, and the eddy currents generate the second alternating magnetic field.

[0063] Clause 5. The medical probe of any one of clauses 1-4, wherein each of the plurality of receiving coils is aligned along a longitudinal axis.

[0064] Clause 6. The medical probe of any one of Clauses 1-5, wherein the plurality of receiving coils comprises three receiving coils symmetrically arranged around the longitudinal axis.

[0065] Clause 7. The medical probe of any of Clauses 1-6, wherein at least a portion of the plurality of receiving coils is surrounded by a transmitting coil.

[0066] Clause 8. The medical probe of any of Clauses 1-7, further comprising: a three-axis sensor disposed within the shaft and configured to output a signal indicative of a position and orientation of the three-axis sensor relative to a magnetic field generated from outside the medical probe.

[0067] Clause 9. The medical probe of Clause 8, wherein at least a portion of the triaxial sensor is surrounded by the transmit coil.

[0068] Clause 10. The medical probe of any of Clauses 1-9, the shaft having a proximal portion and a distal portion, and configured to be manipulated at the proximal portion to position the distal portion into the patient's heart.

[0069] Clause 11. The medical probe of any of clauses 1-10, the one or more electrodes being configured to sense intracardiac electrogram signals.

[0070] Clause 12. The medical probe of any of clauses 1-11, wherein the one or more electrodes are configured to provide a radio frequency signal to ablate tissue.

[0071] Clause 13. The medical probe of any of Clauses 1-12, the one or more electrodes being configured to provide at least 900 V between the electrodes to ablate tissue using irreversible electroporation.

[0072] Item 14. A medical system comprising: a signal generator configured to provide an output signal to a transmitting coil disposed in an axis of a medical probe; and a signal processor configured to: receive multiple input signals from multiple receiving coils disposed in an axis 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 the multiple input signals.

[0073] Item 15. According to the medical system described in Item 14, the multi-electrode basket catheter is configured so that the output signal generates a first alternating magnetic field through the 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 superposition of the first alternating magnetic field and the second alternating magnetic field affects multiple input signals.

[0074] Clause 16. The medical system of clause 14 or clause 15, wherein the signal processor is 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.

[0075] Clause 17. The medical system of any of clauses 14-16, the signal processor further configured to determine a deformed shape 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.

[0076] 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.

[0077] Clause 19. The medical system of clause 18, wherein the visualization module is further configured to graphically present the deformed shape relative to the anatomical map.

[0078] Clause 20. The medical system of any of Clauses 14-19, further comprising: an intracardiac electrogram (IEGM) sensor configured to receive IEGM signals from a plurality of electrodes of the multi-electrode basket catheter.

[0079] Clause 21. The medical system of any of Clauses 14-20, further comprising: a radio frequency (RF) ablation energy generator configured to provide RF signals to a plurality of electrodes of the multi-electrode basket catheter to perform RF ablation of tissue.

[0080] Clause 22. The medical system of any one of Clauses 14-21, further comprising: a pulsed field ablation (PFA) energy generator configured to provide pulse signals to a plurality of electrodes of the multi-electrode basket catheter to perform ablation by irreversible electroporation.

[0081] Clause 23. The medical system according to any one of clauses 14-22 further includes: a magnetic field generator configured to generate a magnetic field in an external predefined working space; and a magnetic tracking signal processor configured to: receive a navigation signal from a three-axis sensor disposed in the axis of the multi-electrode basket catheter, and determine the position and orientation of the three-axis sensor within the predefined working space based at least in part on the navigation signal.

[0082] Item 24. A method comprising: generating a first alternating magnetic field from a transmitting coil disposed in the shaft of a multi-electrode basket catheter; inducing eddy currents on a conductive non-ferromagnetic element at a distal ridge end of a basket assembly coupled to the multi-electrode basket catheter; inducing corresponding electrical signals in a plurality of receiving coils disposed in the shaft of the multi-electrode basket catheter, such that the corresponding electrical signals are 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; and determining a position of the conductive non-ferromagnetic element based at least in part on the corresponding electrical signals.

[0083] 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 corresponding electrical signal.

[0084] Clause 26. The method of Clause 24 or Clause 25, further comprising determining a deformed shape of the basket assembly based at least in part on the corresponding electrical signal.

[0085] Clause 27. The method of clause 26, further comprising: graphically presenting the deformed shape.

[0086] Clause 28. The method of Clause 26, further comprising: graphically presenting the deformed shape relative to the anatomical map.

[0087] Clause 29. The method of any of Clauses 24-28, further comprising: receiving intracardiac electrogram signals from a plurality of electrodes of a multi-electrode basket catheter.

[0088] Clause 30. The method of any of Clauses 24-29, further comprising: generating radiofrequency ablation energy at a plurality of electrodes of a multi-electrode basket catheter.

[0089] Clause 31. The method of any of Clauses 24-29, further comprising: generating pulsed field ablation energy at a plurality of electrodes of a multi-electrode basket catheter.

[0090] Clause 32. The method of any of Clauses 24-31, further comprising: determining a position and orientation of a tri-axial sensor disposed within a shaft of the multi-electrode basket catheter.

[0091] Exemplary embodiments of the subject matter contained herein have been shown and described, and further improvements of the methods and systems described herein may be achieved by appropriate modifications without departing from the scope of the claims. In addition, where the above methods and steps represent specific events that occur in a specific order, it is intended that certain specific steps do not necessarily have to be performed in the order described, but can be performed in any order, as long as the steps enable the implementation to achieve its intended purpose. Therefore, if there are variations of the present invention and the variations belong to the substantive scope of the disclosure of the present invention or equivalents that can be found in the claims, this patent is intended to cover these variations as well. Many such modifications will be obvious to those skilled in the art. For example, the examples, embodiments, geometries, materials, dimensions, ratios, steps, etc. described above are all exemplary. Therefore, the claims should not be limited to the specific details of the structure and operation shown in this written description and the drawings.

Claims

1. A medical probe, comprising: a shaft extending along a longitudinal axis; a plurality of ridges 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 of the plurality of ridges; a transmitting coil disposed within the shaft, aligned along the longitudinal axis and configured to generate a first alternating magnetic field; a positioning element coupled to a distal end of the spine, configured to move relative to the transmitting coil in response to a force on the resilient basket, and 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 positioning element relative to the transmitting coil; and A plurality of receiving coils are disposed within the shaft and are configured to output corresponding electrical signals based at least in part on a superposition of the first alternating magnetic field and the second alternating magnetic field. 2 . The medical probe according to claim 1 , wherein the positioning element comprises a conductive non-ferromagnetic material. 3 . The medical probe according to claim 1 , wherein the transmitting coil and the positioning element are configured such that the first alternating magnetic field induces eddy currents in the positioning element, and the eddy currents generate the second alternating magnetic field. The medical probe of claim 1 , wherein each of the plurality of receiving coils is aligned along the longitudinal axis. 5 . The medical probe according to claim 1 , wherein the plurality of receiving coils comprises three receiving coils symmetrically arranged around the longitudinal axis, wherein at least a portion of the plurality of receiving coils is surrounded by the transmitting coil.

6. The medical probe according to claim 1, further comprising: A three-axis sensor is disposed within the shaft and is configured to output signals 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 claim 1, the one or more electrodes being configured to sense intracardiac electrogram signals, provide radiofrequency signals to ablate tissue, and / or provide at least 900 V between electrodes to ablate tissue using irreversible electroporation.

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

9. According to the medical system of claim 8, the multi-electrode basket catheter is configured so that the output signal generates a first alternating magnetic field through the 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 superposition of the first alternating magnetic field and the second alternating magnetic field affects the multiple input signals.

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

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

12. The medical system of claim 11, further comprising: A visualization module is configured to graphically present the deformed shape for display on a display device and to graphically present the deformed shape relative to an anatomical map.

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

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

15. A method comprising: generating a first alternating magnetic field from a transmitting coil disposed in a shaft of a multi-electrode basket catheter; inducing eddy currents in an electrically conductive, non-ferromagnetic element coupled to a distal spine end of a basket assembly of the multi-electrode basket catheter; inducing corresponding electrical signals in a plurality of receiving coils disposed in a shaft of the multi-electrode basket catheter, such that the corresponding electrical signals are 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; as well as The position of the electrically conductive non-ferromagnetic element is determined based at least in part on the corresponding electrical signal.

16. The method according to claim 15, further comprising: A direction and magnitude of a force applied to the basket assembly is determined based at least in part on the corresponding electrical signal.

17. The method according to claim 15, further comprising: A deformed shape of the basket assembly is determined based at least in part on the corresponding electrical signal.

18. The method according to claim 17, further comprising: The deformed shape is graphically presented relative to an anatomical map.

19. The method according to claim 15, further comprising: Intracardiac electrogram signals are received from electrodes of the multi-electrode basket catheter.

20. The method of claim 15, further comprising: Radiofrequency ablation energy is generated at the multiple electrodes of the multi-electrode basket catheter and / or pulsed field ablation energy is generated at the multiple electrodes of the multi-electrode basket catheter.

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