Device, system, and method for arrhythmia mapping using a multi-electrode mapping catheter system

Abstract

To improve the resolution and clarity of electrical signal mapping for electrophysiological procedures. [Solution] A method and system for mapping electrophysiological signals in the heart using a catheter having an ultra-high density electrode array is disclosed. The disclosed technique may include: navigating a medical probe to a target location in a patient's heart; receiving electrophysiological signals from at least some of a plurality of electrodes; identifying an early excitation point identified as having the earliest excitation time based on the electrophysiological signals and position signals; identifying a plurality of points closest to the early excitation point having an excitation time less than a predetermined duration from the earliest excitation time based on the electrophysiological signals and position signals; and generating an electroanatomical map of the heart based on data corresponding to the plurality of points, wherein the electroanatomical map represents the location of the early excitation point for subsequent ablation.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application is related to U.S. Patent Application No. 16 / 723,971, filed on December 20, 2019 (Attorney Docket No. BIO6160USNP1), U.S. Patent Application No. 17 / 489,895, filed on September 30, 2021 (Attorney Docket No. BIO6160USCIP1(253757.000100)), U.S. Patent Application No. 18 / 159,288, filed on January 25, 2023 (Attorney Docket No. BIO6160USCIP2(253757.000343)), and U.S. Patent Application No. 18 / 969,596, filed on December 5, 2024 (Attorney Docket No. BIO6944USNP1(253757.000561)), and the entire contents and substance of each of these are hereby incorporated by reference into this specification as if fully set forth below.

[0002] (Field of the Invention) This disclosure relates to devices and methods for mapping the heart structure and identifying positions for ablating heart tissue using a catheter having a high - density electrode.

Background Art

[0003] Advances in high - density diagnostic catheters and mapping systems have contributed to substantially more efficient treatments and improved ablation results compared to conventional systems. In the ablation of complex arrhythmias, high - density mapping has improved the visualization of areas of slow conduction (critical isthmus) or macro - reentry circuits. In addition, rapid potential map collection with higher density and improved resolution has reduced mapping and treatment times. In atrial fibrillation ablation procedures, high - density mapping has the potential to visualize areas of gaps or dormant conduction that were previously not visible, thereby improving the durability of pulmonary vein isolation (PVI) and reducing the need for re - ablation.

[0004] However, in practice, current high-density mapping systems have certain limitations. Interference from far-field signals or noise can lead to a decrease in signal fidelity. In complex atrial substrates with multiple atrial potential components, unipolar electrograms referenced to the Wilson central terminal often mistime components due to large, steep far-field potentials, which may require manual review and annotation correction. Other limitations include electrode spacing and sizing, which affect the integrability of ablation and intracardiac echocardiography. [Overview of the project] [Problems that the invention aims to solve]

[0005] Current multi-electrode catheters with fewer electrodes, ring electrodes, or fixed-shape catheters are capable of identifying potential target sites, but increasing the number and types of electrodes in spherical, high-density catheters may enable shorter mapping and procedure times in clinical settings. The systems and methods of this disclosure are intended to improve the resolution and clarity of electrical signal mapping for electrophysiological procedures. [Means for solving the problem]

[0006] The disclosed technology includes a method for navigating a medical probe to a target location within a patient's heart. The medical probe may comprise a plurality of spines extending along a longitudinal axis and configured to bend radially outward from the longitudinal axis. The plurality of spines may comprise a plurality of electrodes disposed thereon and at least one position sensor disposed on the longitudinal axis. The position sensor may be configured to provide a position signal representing the position of the sensor and the medical probe within the heart.

[0007] The method may further include receiving electrophysiological signals from at least some of a plurality of electrodes, and identifying the earliest excitation point, which is identified as having the earliest excitation time, based on the electrophysiological signals and position signals. The method may further include identifying a plurality of points closest to the earliest excitation point, which have an excitation time less than a predetermined duration from the earliest excitation time, based on the electrophysiological signals and position signals. The method may include generating an electroanatomical map of the heart based on data corresponding to the plurality of points. The electroanatomical map may represent the location of the earliest excitation point for subsequent ablation.

[0008] The disclosed technology may further include a medical system comprising a medical probe. The medical probe may comprise a shaft extending along a longitudinal axis, a plurality of spines disposed at the distal end of the shaft and configured to deflect radially outward from the longitudinal axis and define a cavity between them, and a position sensor disposed on the longitudinal axis. The position sensor may be configured to provide a position signal representing the position of the sensor and the medical probe within the heart. The medical probe may further include a plurality of electrodes disposed along the plurality of spines and a reference electrode disposed within the cavity.

[0009] The medical system may further include one or more processors and memory for storing instructions, the instructions being configured, when executed by one or more processors, to cause the medical system to receive electrophysiological signals from at least some of a plurality of electrodes. The instructions may further include causing the medical system to identify an early excitation point identified as having the earliest excitation time based on the electrophysiological and positional signals, to identify a plurality of points closest to the early excitation point having an excitation time less than a predetermined duration from the earliest excitation time based on the electrophysiological and positional signals, and to generate an electroanatomical map of the heart based on the data corresponding to the plurality of points. The electroanatomical map may represent the locations of the early excitation points for subsequent ablation.

[0010] To achieve the above-mentioned and related objectives, certain exemplary embodiments are described herein in connection with the following description and accompanying drawings. However, these embodiments represent only a few of the various ways in which the principle of the claimed subject matter can be used, and the claimed subject matter is intended to encompass all such embodiments and their equivalents. Other advantages and novel features may become apparent from the following detailed description when considered in conjunction with the drawings. [Brief explanation of the drawing]

[0011] The above and further aspects of the present invention are further discussed below with reference to the accompanying drawings, and in various figures, similar numbers indicate similar structural elements and features. The drawings are not necessarily to scale and are primarily intended to illustrate the principles of the present invention. The figures depict one or more implementations of the device of the present invention, not as limitations but merely as examples.

[0012] This patent or application document includes at least one color printed drawing. A copy of this patent or patent application publication containing the color drawing will be provided by the Patent and Trademark Office upon request and payment of the necessary fees. [Figure 1A] This specification illustrates catheter-based electrophysiological mapping and ablation systems, as illustrated by examples of the subject matter disclosed herein. [Figure 1B] Figure 1A is a perspective view of a constructed and operating basket catheter according to an example of the present invention. [Figure 2] Figures 1A and 1B show more detailed diagrams of the expandable assembly of the basket catheter. [Figure 3] Figures 1A and 1B show more detailed diagrams of the expandable assembly of the basket catheter. [Figure 4] Figures 1A and 1B show partially exploded views of the basket catheter. [Figure 5] Figures 1A and 1B show enlarged views of the nose section of the basket catheter with the nose cap removed. [Figure 6A] Schematic diagrams of an expandable assembly of the basket catheters of FIGS. 1A and 1B in an expanded form and a folded form. [Figure 6B] Schematic diagrams of an expandable assembly of the basket catheters of FIGS. 1A and 1B in an expanded form and a folded form. [Figure 7] Schematic diagram of a flexible polymer circuit strip for use in the basket catheters of FIGS. 1A and 1B. [Figure 8A] Cross-sectional view taken along line A-A of FIG. 7. [Figure 8B] Shows exemplary openings formed in the coating of the flexible polymer circuit strip of FIG. 7. [Figure 8C] Shows exemplary openings formed in the coating of the flexible polymer circuit strip of FIG. 7. [Figure 8D] Shows exemplary openings formed in the coating of the flexible polymer circuit strip of FIG. 7. [Figure 8E] Shows exemplary openings formed in the coating of the flexible polymer circuit strip of FIG. 7. [Figure 8F] Shows exemplary openings formed in the coating of the flexible polymer circuit strip of FIG. 7. [Figure 8G] Shows exemplary openings formed in the coating of the flexible polymer circuit strip of FIG. 7. [Figure 8H] Shows exemplary openings formed in the coating of the flexible polymer circuit strip of FIG. 7. [Figure 8I] Shows exemplary openings formed in the coating of the flexible polymer circuit strip of FIG. 7. [Figure 8J] Table showing impedance values for an exemplary opening pattern in the coating of the flexible polymer circuit strip of FIG. 7. [Figure 9] Schematic diagram of a deflectable element of the basket catheters of FIGS. 1A and 1B. [Figure 10] Schematic diagram of an infusion sleeve of the basket catheters of FIGS. 1A and 1B. [Figure 11] Schematic diagrams of the pusher of the basket catheter of FIGS. 1A and 1B. [Figure 12] Schematic diagrams of the multi-axis position sensor of the basket catheter of FIGS. 1A and 1B. [Figure 13A] Schematic diagrams of the nose connector of the basket catheter of FIGS. 1A and 1B. [Figure 13B] Schematic diagrams of the nose connector of the basket catheter of FIGS. 1A and 1B. [Figure 14] Schematic diagrams of the nose connector holder of the basket catheter of FIGS. 1A and 1B. [Figure 15A] Schematic diagrams of the nose cap of the basket catheter of FIGS. 1A and 1B. [Figure 15B] Schematic diagrams of the nose cap of the basket catheter of FIGS. 1A and 1B. [Figure 16] Schematic diagrams of the connector of the basket catheter of FIGS. 1A and 1B.

[0021] [Figure 17] Schematic diagrams of the single-axis position sensor of the basket catheter of FIGS. 1A and 1B. [Figure 18] Schematic diagrams of the proximal retainer ring of the basket catheter of FIGS. 1A and 1B. [Figure 19] Cross-sectional view taken along line A-A of FIG. 1B. [Figure 20] Cross-sectional view taken along line A-A of FIG. 1B. [Figure 21] Another view of the basket catheter with annotations showing various features of the catheter according to an example of the present invention is shown. [Figure 22] A view of the basket catheter showing the expanded and folded states of the basket rendered on a display according to an example of the present invention is shown. [Figure 23A] Patient inclusion and exclusion criteria as part of a catheter test according to an example of the present invention are shown. [Figure 23B] Patient inclusion and exclusion criteria as part of a catheter test according to an example of the present invention are shown. [Figure 24] This is a table showing the baseline attributes and comorbidities of participants registered in a study according to an example of the present invention. [Figure 25A] This is a table showing the history of atrial and ventricular arrhythmias and ablation procedures of participants registered in a trial, as an example of the present invention. [Figure 25B] This is a table showing the history of atrial and ventricular arrhythmias and ablation procedures of participants registered in a trial, as an example of the present invention. [Figure 26] This is a table showing the treatment characteristics of a treatment completed as part of a test, as an example of the present invention. [Figure 27A] This image shows a graphical representation of an atypical flutter time (LAT) map and voltage (bipolar) map of the left atrium of a patient's heart, using a catheter, as an example of the present invention. [Figure 27B] This image shows a graphical representation of an atypical flutter time (LAT) map and voltage (bipolar) map of the left atrium of a patient's heart, using a catheter, as an example of the present invention. [Figure 27C] This image shows a graphical representation of an atypical flutter time (LAT) map and voltage (bipolar) map of the left atrium of a patient's heart, using a catheter, as an example of the present invention. [Figure 27D] This image shows a graphical representation of an atypical flutter time (LAT) map and voltage (bipolar) map of the left atrium of a patient's heart, using a catheter, as an example of the present invention. [Figure 28A] This shows an intracardiac electrocardiogram recording of a patient's heart observed by a catheter, according to an example of the present invention. [Figure 28B] This shows an intracardiac electrocardiogram recording of a patient's heart observed by a catheter, according to an example of the present invention. [Figure 29] This shows a graphical representation of a catheter positioned within a patient's heart to complete a mapping procedure, according to an example of the present invention. [Figure 30]This image shows a graphical representation of a catheter positioned within a patient's heart, indicating a mapped and identified QS P-wave localized atrial tachycardia site in the anterior left carina region, according to an example of the present invention. [Figure 31] This table summarizes regions of interest identified using a catheter in participants with atrial tachycardia, including PVI triggers, PVI breakthroughs, non-PV AF lesions, the left atrial critical isthmus, and the inferior vena cava tricuspid isthmus, according to an example of the present invention. [Figure 32] An example of the present invention is shown, illustrating a PVC map with the earliest QS pre-QRS site identified in the septal RVOT using a catheter. [Figure 33] An example of the present invention shows the region and surrounding area of ​​the earliest excitation time position, calculated and compared to a map reference. [Figure 34] This is a table summarizing all PVC cases, identifying the earliest point from the intermediate QRS (reference), the earliest point before the QRS, the region of the earliest excitation point, and the area around the earliest excitation point, according to an example of the present invention. [Figure 35] A flowchart illustrating an example of a method using a catheter according to the present invention is shown. [Figure 36] An outline of a method using a catheter, according to one example of the present invention, is shown below. [Modes for carrying out the invention]

[0013] The disclosed technique includes a catheter having multiple spines and high-density electrodes arranged along the spines. As will become apparent through this disclosure, the disclosed system and method may be used to create a more accurate electroanatomical map of a patient's heart. Furthermore, the disclosed technique may help to accurately identify locations within the heart to be ablated in order to reduce or eliminate abnormal electrical signals within the heart. In particular, the disclosed technique includes identifying the location of the earliest excitation time in the heart and multiple points closest to the earliest excitation point that have an excitation time less than a predetermined duration from the earliest excitation time (e.g., less than 1 second, less than 10 milliseconds, less than 1 millisecond). In this way, an electroanatomical map of the patient's heart may be generated to identify the locations to be ablated.

[0014] While exemplary embodiments of the disclosed technology are described in detail herein, it should be understood that other embodiments are also contemplated. Therefore, the scope of the disclosed technology is not intended to be limited to the structural and arrangement details of the components described or illustrated in the drawings below. Other embodiments of the disclosed technology are possible and can be implemented or performed in various ways.

[0015] Note that, as used herein and in the appended claims, the singular “a,” “an,” and “the” include multiple references unless the context specifically indicates otherwise. “Comprising,” “containing,” or “including” means that at least the compound, element, particle, or process step mentioned is present in the composition, article, or method, but does not exclude the presence of other such compounds, materials, particles, or process steps, even if those other compounds, materials, particles, or process steps have the same function as the one mentioned.

[0016] Where used herein, the terms “about” or “approximately” for any number or range indicate a preferred dimensional tolerance that enables some or all of the components to function for the intended purposes described herein. More specifically, “about” or “approximately” can refer to a range of values ​​within ±20% of the enumerated values, for example, “about 90%” can refer to a range of values ​​between 71% and 99%.

[0017] As discussed herein, the heart or vascular system of a “subject” or “patient” may be the heart or vascular system of a human or any animal. The term “proximal” means that the subject is closer to the physician, and “distal” means that the subject is further away from the physician.

[0018] As used herein in the context of circuit strips, the term “longitudinal direction” refers to the direction along the length of the strip, extending from the proximal end to the distal end. The term “transverse direction” refers to the direction perpendicular to the longitudinal axis, extending across the width of the strip. The term “thickness” refers to a dimension perpendicular to both the longitudinal and transverse directions, indicating the depth of the strip from the top surface (i.e., upper layer) to the bottom surface (lower layer).

[0019] The following detailed description includes many specific details to help fully understand the invention. However, it will be understood by those skilled in the art that the subject matter disclosed herein can be carried out without these specific details. In other cases, well-known methods and features are not described in detail so as not to obscure the subject matter disclosed herein.

[0020] In describing exemplary embodiments, technical terms will be used for clarity. Each term is intended to have its broadest meaning as understood by those skilled in the art and is intended to include all technical equivalents that operate similarly to achieve similar purposes. It should also be understood that reference to one or more steps of a method does not preclude the existence of additional step-by-step steps or step-by-step steps intervening between those expressly identified steps. The steps of a method may be performed in an order different from that described herein without departing from the scope of the disclosed art. Similarly, reference to one or more components in a device or system should also be understood that does not preclude the existence of additional components or components intervening between those expressly identified components.

[0021] System Description Refer to Figure 1A, which shows an exemplary catheter-based electrophysiological mapping and ablation system 100. The system 100 includes multiple catheters that are percutaneously inserted by a physician 5 through the patient's vascular system into a lumen or vascular structure of the heart 112. Typically, a delivery sheath catheter is inserted into the left or right atrium near a desired location in the heart 112. One or more catheters may then be inserted into the delivery sheath catheter to reach a desired location within the heart 112. The multiple catheters may include a catheter dedicated to detecting intracardiac electrogram (IEGM) signals, a catheter dedicated to ablation, and / or a catheter dedicated to both detection and ablation. An exemplary catheter 10 configured for ablating tissue and / or detecting and / or mapping electrical cardiac activity is shown in the inset of Figure 1A.

[0022] The catheter 10 is an exemplary catheter having an end effector at its distal tip, which includes an expandable assembly 22, the expandable assembly having one, preferably more, electrodes 26 optionally distributed across a plurality of flexible spine elements 24 (sometimes referred herein as “flexible polymer circuit strips 24”). The electrodes 26 are generally configured to deliver ablation energy to tissue and / or to detect electrophysiological signals (e.g., IEGM signals). The catheter 10 additionally includes one or more position sensors 74 embedded in or near the distal tip to track the position and orientation of the distal tip. Optionally and preferably, the position sensors 74 are magnetic-based position sensors, e.g., a position sensor including three magnetic coils for detecting three-dimensional (3D) position and orientation, or a position sensor including one magnetic coil for detecting a single direction. In some examples, the catheter 10 may include a first position sensor 74 positioned near the proximal end of the expandable assembly 22 and a second position sensor 74 positioned near the distal end of the expandable assembly. In this way, the positions of the first and second position sensors 74 may be used to determine the extension and shape of the expandable assembly 22. This may be useful in determining when the expandable assembly 22 is ready to be retracted into the sheath, and when the expandable assembly is fully deployed for mapping and / or ablation.

[0023] Each of the magnetic-based position sensors 74 may work in conjunction with a position pad 125 which includes a plurality of magnetic coils 132 configured to generate a magnetic field within a given working volume. The real-time position of the distal tip of the catheter 10 can be tracked based on the magnetic field generated using the position pad 125 and detected by the magnetic-based position sensors 74. Details of 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, each of which is incorporated herein by reference in whole.

[0024] Physician 5 can position the distal tip of the catheter 10 in contact with the heart wall to detect the target site in the heart 112. Similarly, for ablation, Physician 5 can position the distal end of the ablation catheter in contact with the target site for tissue ablation.

[0025] System 100 includes one or more electrode patches 138 positioned to contact the skin of a patient 23 in order to establish a position reference for the position pad 125 and impedance-based tracking of the electrodes 26. In the case of impedance-based tracking, the position of each electrode is detected at the electrode skin patch 138, with current directed to the electrodes 26, so that the position can be triangulated through the electrode patch 138. 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, each of which is incorporated herein by reference in whole.

[0026] The recorder 111 records and displays the electromagnetism 121 captured by the surface ECG electrode 118 and the intracardiac electromagnetism (IEGM) captured by the electrode 26 of the catheter 10. The recorder 111 may include pacing capabilities for pacing the rhythm of the heart and / or may be electrically connected to a standalone pacer.

[0027] System 100 may include an ablation energy generator 150 adapted to conduct ablation energy to one or more electrodes at the distal tip of a catheter configured for ablation. The energy generated by the ablation energy generator 150 may include, but is not limited to, radiofrequency (RF) energy, pulsed-field ablation (PFA) energy including unipolar or bipolar high-voltage DC pulses that may be used for irreversible electroporation (IRE), or a combination thereof.

[0028] The patient interface unit (PIU) 130 is an interface configured to establish electrical communication between the catheter, other electrophysiological devices, a power supply, and a workstation 155 for controlling the operation of the system 100. The electrophysiological devices of the system 100 may include, for example, multiple catheters, position pads 125, surface ECG electrodes 118, electrode patches 138, an ablation energy generator 150, and a recorder 111. Optionally, and preferably, the PIU 130 additionally includes processing capabilities for implementing real-time calculation of catheter position and performing ECG calculations.

[0029] The workstation 155 includes memory, a processor unit having memory or storage device internally storing appropriate operating software, and user interface functions. The workstation 155 may optionally provide several functions, including (1) modeling the anatomical structure within the heart in three dimensions (3D) and rendering the model or anatomical map 120 for display on a display device 127, (2) displaying on the display device 127 a representative visual representation or image of an excitation sequence (or other data) compiled from a recorded electrophoresis diagram 121 superimposed on the rendered anatomical map 120, (3) displaying the real-time position and orientation of multiple catheters within the cardiac chambers, and (4) displaying on the display device 127 sites of interest, such as where ablation energy is being applied or to be applied. One commercially available product embodying the elements of System 100 is the CARTO®3 system, available from Biosense Webster, Inc. (31 Technology Drive, Suite 200, Irvine, CA 92618).

[0030] In some examples, the research catheter is a multi-electrode ECG mapping catheter that functions in conjunction with the CARTO® 3 EP navigation system. It is designed to be deployed into the cardiac chambers through an 8.5 F guide sheath. In some examples, as described in more detail herein, this bidirectional deflectable catheter may include 10 basket-shaped spines on its deflectable tip, each spine having 10 coated electrodes used for stimulation and recording. Additionally, the catheter 10 may include two position sensors 74 located along the longitudinal axis near the distal end of the catheter 10.

[0031] In some examples, an irrigation module is provided to deliver an irrigation fluid, such as saline solution, to the treatment site. The irrigation module may include a pump and associated fluid tanks.

[0032] Catheter explanation overview The deflectable bidirectional mapping catheter described herein is designed with 100 electrodes coated across 10 spines to form a basket shape. It has an 8Fr shaft that fits an 8.5Fr sheath for advancement into the cardiac chambers. The basket has a size that can accommodate diameters from a minimum of 3 mm to a maximum of 18 mm, allowing mapping across the entire range of deployment as needed at specific anatomical locations. The basket array consists of 10 nitinol spines, with a stacked flexible printed circuit (100 electrodes in total) on each spine having 10 small outward-facing gold electrodes (0.5 mm² surface area and 1.7 mm inter-electrode spacing, center-to-center) and is proximal to a flat nose tip. The electrodes are flat with impedance-reducing coatings, enabling reduced electrical impedance, improved signal quality, and a superior signal-to-noise ratio compared to previous high-density mapping catheters.

[0033] Three magnetic sensors, two in the distal portion and one in the proximal portion, are embedded in the basket array, transmitting positional and angular information independent of the advanced catheter's position to the CARTO®3 system (Biosense Webster, Inc.) with system accuracy <1 mm. Below the spine on the deflectable tip are two electrodes enabling visualization of the shaft on the CARTO®3 system. A TRUEref electrode (Biosense Webster, Inc.) embedded in the center of the sphere can be used as an intracardiac non-contact central reference electrode or a nearby unipolar reference electrode, enabling enhanced recognition and filtering of input signals for map annotation. CARTO®3 software version 7 was adapted to reduce the need for manual annotation, and added features included an automated outlier detection and point binning algorithm called "Wisdom of the crowd (WofC)". As described in more detail herein, this feature has an accuracy of 1 mm 3 Outlier time or voltage annotations are removed based on specific criteria collected within a predefined fast anatomical mapping (FAM) region (voxel).

[0034] Detailed explanation of the catheter Herein, we refer to Figure 1B, a schematic diagram of a basket catheter 10 constructed and operating according to one embodiment of the present invention. The basket catheter 10 includes an elongated deflectable element 12 having a distal end 14, a connector 16 connected to the distal end 14, and a pusher 18 including a distal portion 20. The pusher 18 is configured to move forward and backward through the deflectable element 12, for example, using a manipulator or handle (not shown). The basket catheter 10 also includes an expandable assembly 22 comprising a plurality of flexible polymer circuit strips 24 (sometimes referred to herein as “spines” - only some are referenced for simplification). Each flexible polymer circuit strip 24 includes a plurality of electrodes 26 disposed thereon (only some are referenced for simplification). The formation of the various elements and the methods by which they are connected to one another will be described in more detail with reference to Figures 4 to 20.

[0035] Referring now to Figures 2 and 3, these are detail views of the expandable assembly 22 of the basket catheter 10 shown in Figures 1A and 1B. Figures 2 and 3 show the electrodes 26 on the flexible polymer circuit strip 24 more clearly. Figure 2 shows that the electrodes 26 are not positioned on the proximal portion of the flexible polymer circuit strip 24, although this may be the case in some examples. The basket catheter 10 includes a nose connector 30 connected to the distal portion 20 of the pusher 18. The flexible polymer circuit strip 24 is connected to the nose connector 30 via a hinge 28 (only partially referenced for simplification) of the flexible polymer circuit strip 24.

[0036] Now, refer to Figures 4 and 5. Figure 4 is a partially exploded view of the basket catheter 10 shown in Figures 1A and 1B. Figure 5 is a magnified view of the nose section of the basket catheter 10 shown in Figures 1A and 1B with the nose cap 32 removed.

[0037] Figure 4 shows the nose cap 32 and connector 16 removed from the basket catheter 10 to illustrate how the flexible polymer circuit strip 24 is connected to the nose connector 30 and connector 16. The nose connector 30 is connected to the distal portion 20 of the pusher 18. The proximal end of the connector 16 may be connected to the elongated deflectable element 12 using an adhesive, such as epoxy, and any preferred connection method. The nose connector 30 is secured to the distal portion 20 of the pusher 18 using a central electrode ring 40, which is described in more detail with reference to Figures 14 and 19. The flexible polymer circuit strip 24 is circumferentially arranged around the distal portion 20 of the pusher 18, and the first end 42 of the strip 24 (only partially referenced for simplification) is connected to the inner surface 44 of the connector 16. The connection between the flexible polymer circuit strip 24 and the inner surface 44 is shown more clearly with reference to Figure 20.

[0038] As shown in Figures 2–4, the catheter may further include a reference electrode 31 that can be mounted in the center of an expandable assembly 22 along a longitudinal axis extending through its center. The reference electrode 31 is configured to detect electrophysiological signals propagating through blood or other fluids and may be used to reduce noise detected by electrode 26. As understood, the electrophysiological signal detected by the reference electrode 31 is compared to or subtracted from the electrophysiological signal detected by electrode 26 in contact with the tissue, thereby reducing or eliminating far-field noise and achieving a more accurate reading of the electrophysiological signal propagating through the tissue.

[0039] The disclosed technique may be configured to obtain accurate electrophysiological signals by measuring electrophysiological signals at an electrode 26 on a spine 24, two or more electrodes 26 on a spine, and / or a reference electrode 31. For example, a unipolar measurement can be performed between an electrode 26 on a spine 24 and a reference electrode 31, allowing for the elimination of far-field noise. Furthermore, a bipolar measurement can be performed between two or more electrodes 26 on a spine 24 to determine the electrophysiological signals at each electrode 26 and to determine the electrophysiological signals between a given set of electrodes 26. For example, a bipolar measurement can be achieved between a first electrode 26 on a spine 24 and a second electrode 26 on the same spine 24. Alternatively, a bipolar measurement can be achieved between a first electrode 26 on a first spine 24 and a second electrode 26 on a second spine 24. As understood, the disclosed technique may be configured to achieve highly accurate electrophysiological measurements by measuring and comparing electrophysiological signals between any of the electrodes 26 and / or the reference electrode 31.

[0040] Furthermore, the disclosed technology may be configured to correlate the position of a specific electrode 26 with electrophysiological data obtained by that specific electrode 26. In this way, the disclosed technology may be configured to accurately output positional and electrophysiological data in order to generate a high-density electrophysiological map of the patient's heart.

[0041] Figure 5 shows that the nose connector 30 includes a distal receiving portion 34 having an inner surface 36 and a distally facing opening 38. The nose connector 30 is described in more detail with reference to Figures 13A-13B and Figure 19. Figure 5 shows that the second end 46 (Figure 5) (partially referenced for simplification) of the strip 24, each having a hinge 28 (Figure 5), enters the distally facing opening 38 (Figure 5) and connects to the inner surface 36 (Figure 5) of the distal receiving portion 34 (Figure 5) of the nose connector 30.

[0042] Figure 4 shows that the basket catheter 10 also includes each elongated elastic support element 48 connected along a given length of each strip of flexible polymer circuit strips 24 that provide the shape of the expandable assembly 22 in the expanded form of the expandable assembly 22. The elongated elastic support elements 48 may form or be part of a spine and may include any suitable material, not limited to, for example, nitinol and / or polyetherimide (PEI).

[0043] Figure 4 shows that each elongated elastic support element 48 extends from the connector 16 along the inner surface of each strip 24, while Figure 5 shows that the elongated elastic support elements 48 extend along each flexible polymer circuit strip 24 up to the front of each hinge 28. Inset 50 of Figure 5 shows one of the hinges 28 and a portion of one of the flexible polymer circuit strips 24 adjacent to that hinge 28. Inset 50 shows that the elongated elastic support element 48 does not extend into the region of the hinge 28. It can also be seen that the hinge region is much thinner than the region containing the elongated elastic support element 48. The hinge 28 may have any preferred thickness in the range of, for example, about 10 to about 140 micrometers. The strips 24 are folded so that the strips 24 define a configuration that is generally perpendicular to each other (inset 50).

[0044] In some embodiments, each of the flexible polymer circuit strips 24 includes a polyimide layer. The flexible polymer circuit strips 24 may be composed of any suitable material. The flexible polymer circuit strips 24 are described in more detail with reference to Figures 7 and 8.

[0045] Figure 5 also shows that each end of the second end 46 of each strip of the flexible polymer circuit strip 24 tapers along the width of each strip of the flexible polymer circuit strip 24, allowing the second end 46 to be inserted into the distal receiving portion 34 without overlapping. The hinge 28 can be connected to the inner surface 36 of the distal receiving portion 34 using any suitable adhesive, such as epoxy, and / or any suitable connection method.

[0046] The hinges 28 of the flexible polymer circuit strips 24 are supported by threads 52 of a length typically extending to the length of each respective flexible polymer circuit strip 24. Each flexible polymer circuit strip 24, along with the threads 52 and associated elongated elastic support elements 48, may be coated with a suitable covering 54, for example, a thermoplastic polymer resin shrink packaging (PET) as described in more detail with reference to Figure 8A. The threads 52 may be any suitable high-strength polymer, including, for example, ultra-high molecular weight polyethylene (Spectra or Dyneema), Kevlar, or liquid crystal polymer (Vectran).

[0047] Here, refer to Figures 6A and 6B, schematic diagrams showing the expandable assembly 22 of the basket catheter 10 in its expanded and folded forms, respectively, as shown in Figures 1A and 1B. The flexible polymer circuit strip 24 is configured to flex radially outward when the pusher 18 retracts to expand the expandable assembly 22 from the folded form to the expanded form. The folded form of the expandable assembly 22 represents the unstressed form of the flexible polymer circuit strip 24, whose shape is provided using elongated elastic support elements 48 (Figure 4).

[0048] In some embodiments, the flexible polymer circuit strip 24 is formed as a flat strip, as described in more detail with reference to Figure 7. The distal end of the flexible polymer circuit strip 24 is connected to the inner surface 36 of the nose connector 30 (Figure 5). At this point, the flat flexible polymer circuit strip 24 is approximately parallel to line 58, which is an extension of the axis of the nose connector 30 that extends distally beyond the distal end of the nose connector 30. The proximal end of the flexible polymer circuit strip 24 is then connected to the connector 16 such that, in the folded configuration, the angle between the tangent 56 and line 58 to the flexible polymer circuit strip 24 is close to 180 degrees, while in the extended configuration, the angle between the tangent 56 and line 58 is approximately 90 degrees. Therefore, during operation (when the flexible polymer circuit strip 24 is connected to the nose connector 30 and the connector 16), the hinge 28 is configured to provide a maximum angular range of approximately 90 degrees, generally exceeding 80 degrees, for the movement of the flexible polymer circuit strip 24. However, the hinge 28 can bend more than 180 degrees. The maximum angular range is defined as the maximum angular range between the tangent 56 and line 58 to the flexible polymer circuit strip 24. The tangent 56 to the most distal portion of the flexible polymer circuit strip 24 generally provides the maximum angular range between the flexible polymer circuit strip 24 and line 58.

[0049] Herein, we refer to Figure 7, a schematic diagram of a flexible polymer circuit strip 24 for use in the basket catheter 10 of Figures 1A and 1B. The flexible polymer circuit strip 24 may be formed from a single polymer component such as polyimide. The circuit strips 24 may be connected to each other by polyimide or assembled as individual components that are held in proper alignment and secured to a connector 16. Manufacturing the circuit strips 24 as individual components may increase the yield of the base circuit, as a faulty electrode results in the discarding of one circuit strip rather than the entire strip assembly. Each first end 42 of each flexible polymer circuit strip 24 includes an electrical connection array 60. Inset 62 shows that the electrical connection array 60 includes electrical contacts 64 on it (only some are referenced for simplification). The electrical contacts 64 are connected to each electrode of the electrodes 26 disposed on the front of the flexible polymer circuit strip 24 via traces (not shown) on the rear surface of the flexible polymer circuit strip 24. Apart from the region of the first end 42, the flexible polymer circuit strips 24 separate from each other, allowing the flexible polymer circuit strips 24 to form an expandable assembly 22 (Figures 1A and 1B) when connected to the basket catheter 10. Wires (not shown) may connect the electrodes 26 to a control circuit (not shown) via electrical contacts 64. The wires may be arranged within the lumen 66 (Figure 4) of the elongated deflectable element 12 (Figure 4).

[0050] The flexible polymer circuit strip 24 may have any suitable dimensions. For example, the length of the flexible polymer circuit strip 24 may be in the range of 10 mm to 60 mm, for example 30 mm; the width of the flexible polymer circuit strip 24 may be in the range of 0.25 mm to 3 mm, for example 0.72 mm; and the thickness of the flexible polymer circuit strip 24 may be in the range of 0.005 mm to 0.14 mm.

[0051] Here, we refer to Figure 8A, a cross-sectional view taken through line AA in Figure 7. The yarn 52 extends along and beyond the length of the elongated elastic support element 48, which is formed, for example, from nitinol or PEI, and as a result, the yarn 52 also extends to the length of the hinge 28, which is made of the flexible polymer circuit strip 24. The elongated elastic support element 48 may have any preferred thickness in the range of, for example, 0.025 mm to 0.25 mm. A coating 68, such as thermoplastic polymer resin shrink packaging (PET), is placed over the yarn 52 and the elongated elastic support element 48. Epoxy is injected into the coating 68. Heat is then applied to the coating, thereby shrinking the coating over the yarn 52 and the elongated elastic support element 48. One reason for covering the elongated elastic support element 48 with the coating 68 is to electrically insulate the elongated elastic support element 48 from the circuit traces of the flexible polymer circuit strip 24. The coating 68 may be omitted, for example, if the elongated elastic support element 48 is covered with an insulating coating (e.g., polyurethane) or is made of an insulating material.

[0052] The yarn 52 may include any one or more of the following: ultra-high molecular weight polyethylene yarn, or yarn spun from liquid crystal polymer. The yarn 52 may have any preferred linear density in the range of 25 denier to 250 denier, for example.

[0053] Next, the flexible polymer circuit strip 24 is placed on the thread 52 and the elongated elastic support element 48 with the circuit trace side of the flexible polymer circuit strip 24 facing the elongated elastic support element 48 and the electrodes 26 of the flexible polymer circuit strip 24 facing away from the elongated elastic support element 48. The coating 54 is arranged around the combination of the flexible polymer circuit strip 24, the thread 52, and the elongated elastic support element 48, and epoxy 70 is injected into the coating 54. The coating 54 is then heated, thereby shrinking the coating 54 around the combination. Thus, the flexible polymer circuit strip 24 is coated with the coating 54, for example, thermoplastic polymer resin shrink packaging (PET).

[0054] As shown in Figure 8A, openings 55 can be formed through the coating 54 to expose the electrodes 26. In some examples, the openings 55 may expose the entire outer surface of each electrode 26, or the openings may expose only a portion of the outer surface of each electrode 26. The openings 55 may be formed by cutting the coating 54 using a laser or by other means to expose the electrodes 26. In other examples, the openings 55 may be formed by mechanically removing the coating 54, by chemically etching the coating, by plasma etching the coating, or by other preferred methods of removing the coating 54 to form the openings 55. The coating 54 may be removed such that the conductive surface of each electrode 26 is located about 12 micrometers below the outer surface of the coating 54. When the openings 55 expose only a portion of the outer surface of each electrode 26, as described in more detail in relation to Figures 8B to 8I, the openings 55 may include several small openings 55 that collectively define conductive regions that are less than 50% of the conductive surface of the electrode 26.

[0055] Some or all of the electrodes 26 may also be coated with a coating 27 to help ensure that the electrodes 26 can properly detect the electrical signals of the heart. The coating 27 can be any type of coating suitable for the application. In non-limiting examples, the coating 27 may be poly(3,4-ethylenedioxythiophene) (PEDOT), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), electrochemically grown iridium oxide, electrochemically grown titanium nitride (TiN), or any other suitable coating for a particular application. The coating 27 may help reduce the overall impedance of the electrodes 26. In some examples, the coating 27 may be applied to the exposed surface of the electrodes 26 so that the overall impedance can be reduced by about 99% at low frequencies. As an example, the coating 27 may be configured so that the input impedance to each electrode 26 is measured to be less than 13,000 ohms at 1 Hz.

[0056] The coating 27 may be a hydrogel that can be electrochemically grown or adhered to the electrodes 26 as an electric current passes through them. In other examples, the coating 27 may be mechanically applied to each electrode 26 by spraying, painting, dipping, or otherwise covering the electrodes 26 with the coating 27. The coating may have a thickness of 10 nanometers to 10 micrometers. In some examples, the coating may be thinner than the thickness of the covering 54 so that the covering 54 may help protect the coating 27 from contact with connectors 16, deflectable elements 12, or other objects that could damage the coating 27.

[0057] Herein, we refer to Figures 8B to 8I, which show exemplary openings 55 formed in the coating of the flexible polymer circuit strip of Figure 7. By forming openings 55 formed through the coating 54 and exposing the surface of the electrode 26, the exposed surface of the electrode 26 can be coated with coating 27. As shown in Figures 8B to 8I, the openings 55 can be of many shapes, sizes, and configurations. As will be understood by those skilled in the art, by changing the shape, size, and configuration of the openings 55, the amount of exposed surface area of ​​the electrode 26 can be increased or decreased, and the conductive surface area of ​​the electrode 26 can be effectively increased or decreased. Furthermore, by increasing or decreasing the exposed surface area of ​​the electrode 26, the amount of coating 27 that can be applied to the openings 55 will also increase or decrease. In other words, as the size of the openings 55 increases, the surface area of ​​the coating 27 within each opening 55 also increases, which may make it more likely that the coating 27 will rub against an object and peel off. Therefore, as the size of the opening 55 decreases, the coating 54 can provide more mechanical protection to the coating 27, so as to help reduce the likelihood of the coating 27 coming into contact with an object when the basket catheter 10 is used. However, as is understood, as the size of a given opening 55 decreases, the conductive surface area of ​​the electrode 26 will also decrease. Therefore, the size, shape, and configuration of the opening 55 on the electrode 26 can also be optimized to ensure that the coating 54 provides sufficient mechanical protection to the coating 27 while allowing the electrode to adequately detect electrical signals. Manufacturability is another consideration. Currently, the feature of the coating 54 is preferably at least 0.003 inches (76 micrometers) to avoid damage to the coating 54 between the openings 55 during manufacturing.

[0058] Figure 8B shows an exemplary electrode 26 of a flexible polymer circuit strip 24 having circular openings 55A through a coating 54. In this example, eight circular openings 55A can be formed through the coating 54, with each circular opening 55A being equally spaced apart from one another. As can be seen, depending on the application, more or fewer circular openings 55A may be formed through the coating 54. Furthermore, in some examples, the circular openings 55A may be unequally spaced apart from one another. The coating 27 can be applied to the exposed surfaces of the electrode 26 within each circular opening 55A.

[0059] In other examples, the openings 55 can include polygons. For example, Figure 8C shows an electrode 26 of a flexible polymer circuit strip 24 having rectangular openings 55B through a coating 54. In this example, 15 rectangular openings 55B may be formed through the coating 54, and each rectangular opening 55B is equally spaced apart from one another. The rectangular openings 55B may include squares or other rectangular shapes. As another example, Figure 8D shows an electrode 26 of a flexible polymer circuit strip 24 having decagonal openings 55C through a coating 54. In this example, 15 decagonal openings 55C may be formed through the coating 54, and each decagonal opening 55C is equally spaced apart from one another. As yet another example, Figure 8E shows an electrode 26 of a flexible polymer circuit strip 24 having triangular openings 55D through a coating 54. In this example, 19 triangular openings 55D may be formed through the coating 54. The triangular openings 55D can be offset between each row of triangular openings 55D, such that the first row contains four triangular openings 55D and the second row contains three triangular openings 55D. Furthermore, alternating rows can be reversed relative to the previous row. This may allow the tip of an inverted triangular opening 55D to be partially nested between two other triangular openings 55D in the previous row. The coating 27 can be applied to the exposed surfaces of the electrode 26, such as within each rectangular opening 55B, decagonal opening 55C, and triangular opening 55D.

[0060] As will be understood by those skilled in the art, various other shapes and sizes of openings 55 can be formed through the covering 54 to expose the surface of the electrode 26. Furthermore, openings 55 of various shapes can be formed through the covering 54 on a single electrode 26. For example, a circular opening 55A, a decagonal opening 55C, and a triangular opening 55D can be formed together on a single electrode 26. Similarly, one size of opening 55 can be formed through the covering 54 on the electrode 26, along with openings 55 of different sizes. Moreover, the openings 55 can be spaced equally or unevenly across the surface of the electrode 26.

[0061] Figures 8F and 8G show exemplary electrodes 26 of a flexible polymer circuit strip 24 having openings 55 which are elongated slits 55E, 55F formed through a coating 54. At least four elongated slits 55E, 55F may be formed through the coating 54 to expose the surface of the electrode 26, but it will be understood that more or fewer elongated slits 55E, 55F may be formed depending on the application. In the example shown in Figure 8F, the elongated slits 55E may extend longitudinally from near one end of the electrode 26 to near a second end of the electrode 26. In the example shown in Figure 8G, the elongated slits 55E may extend transversely from near one end of the electrode 26 to near a second end of the electrode 26.

[0062] As will be understood by those skilled in the art, a larger continuous surface area of ​​the electrode 26 can be exposed by forming elongated slits 55E, 55F through the coating 54, which can help increase the exposed conductive surface area of ​​the electrode 26, but may also increase the possibility of the coating 27 being rubbed off during use. Therefore, the spacing and size of the elongated slits 55E, 55F can be modified to help ensure that the coating 27 is adequately protected while ensuring that the electrode 26 has a sufficient amount of exposed surface area.

[0063] Figure 8H shows an exemplary electrode 26 of a flexible polymer circuit strip 24 having an opening 55 which is an elongated slit 55G formed through the coating 54. Unlike the elongated slits 55E, 55F shown in Figures 8F and 8G, the elongated slit 55G extends only to a portion of the length of the electrode 26 (e.g., less than approximately one-third of the length of the electrode 26). In this way, the elongated slit 55G can be configured to provide greater mechanical protection to the coating 27, while still ensuring that a sufficient amount of the electrode 26 is exposed.

[0064] Figure 8I shows an exemplary electrode 26 of a flexible polymer circuit strip 24 having a combination of a circular opening 55A and an elongated slit 55E. In this example, the elongated slit 55E may help increase the exposed surface area of ​​the electrode 26, while the circular opening 55A may also help provide greater mechanical protection to the coating 27 while exposing a portion of the surface area of ​​the electrode 26. As will be understood by those skilled in the art, any combination of the exemplary openings 55A-55D and the elongated slits 55E-55G may also help ensure that the coating 27 is adequately protected while ensuring that a sufficient amount of the electrode 26 is exposed.

[0065] Herein, we refer to Figure 8J, which is a table (Table 1) showing impedance values ​​for exemplary patterns of openings 55 formed in the coating of the flexible polymer circuit strip of Figure 7. Table 1 shows experimentally obtained impedance values ​​for several selected patterns of openings 55, although impedance values ​​may be obtained for any of the patterns of openings 55 described herein. Therefore, Table 1 should not be interpreted as limiting, but is provided to show impedance values ​​for several exemplary patterns of openings 55.

[0066] As shown in Figure 8J, impedance values ​​(in ohms) for six different aperture patterns 55 and two control samples (one with a coating 27 covering approximately 100% of the electrode surface 26 and one without any coating 27) are shown at frequencies of 1 Hz, 10 Hz, 50 Hz, and 100 Hz. As shown, the impedance generally decreases as the input frequency increases. Furthermore, the impedance value is inversely proportional to the exposed surface area. For illustrative purposes, illustrative diagrams of the six different aperture patterns 55 are shown in Table 1 below.

[0067] Table 1, from left to right, shows the impedance data for a first exemplary electrode 26 (Example 1), having three rows of seven circular openings 55A in each row. The impedance of Example 1 may range from approximately 10406 ​​± 920 ohms at 1 Hz to approximately 168 ± 28 ohms at 100 Hz. Example 2 similarly shows an electrode 26 with circular openings 55A, but Example 2 includes two rows of five circular openings 55A in each row. As shown in the figure, the impedance of Example 2 may range from approximately 12502 ± 552 ohms at 1 Hz to approximately 206 ± 20 ohms at 100 Hz. As can be understood, Example 2 may be more mechanically robust because, since the surface area of ​​the electrode 26 coated with coating 27 is smaller, the coating 54 covers a larger amount of the surface area of ​​the electrode 26, and more coating 54 material can be located between each circular opening 55A.

[0068] Continuing from left to right in Table 1, Example 3 shows an electrode 26 having four elongated slits 55E extending from near one end of the electrode 26 to near the second end of the electrode 26. The impedance of Example 3 may range from approximately 7000 ± 467 ohms at 1 Hz to approximately 109 ± 4 ohms at 100 Hz. Example 4 shows an electrode 26 having three rows of elongated slits 55G, each elongated slit 55G extending to only a portion of the surface of the electrode 26. Specifically, Example 4 includes three elongated slits 55G in three rows. The impedance of Example 4 may range from approximately 10544 ± 235 ohms at 1 Hz to approximately 164 ± 8 ohms at 100 Hz. As can be seen, since the elongated slits 55G of Example 4 extend to only a portion of the surface of the electrode 26, the coating 27 may be more mechanically protected by the coating 54 compared to Example 3.

[0069] Examples 5 and 6 in Table 1 show electrodes 26 having openings 55 sized to expose approximately one-third and two-thirds of the electrode 26, respectively. As shown in the figure, the impedance value of Example 5 may range from approximately 16921 ± 4158 ohms at 1 Hz to 306 ± 77 ohms at 100 Hz, while the impedance value of Example 6 may range from approximately 9951 ± 407 ohms at 1 Hz to 186 ± 24 ohms at 100 Hz. As can be understood, the impedance can be reduced by having a larger opening size 55, as shown in Example 6, but the coating 27 may be more prone to damage because the covering 54 does not provide much mechanical protection to the coating 27.

[0070] The two rightmost columns in Table 1 contain impedance values ​​for two control cases for reference. First, a control is shown where nearly 100% of the electrode 26 is coated with coating 27. In this example, the overall impedance may range from approximately 6629 ± 197 ohms at 1 Hz to 117 ± 3 ohms at 100 Hz. The second control case shows an electrode whose surface is not coated with coating 27. The impedance value of the electrode 26 without coating 27 may range from approximately 265513 ± 9186 ohms at 1 Hz to 3636 ± 182 ohms at 100 Hz. As these two control cases demonstrate, coating 27 can significantly reduce the overall impedance of the electrode 26. However, as previously discussed, if the coating 27 is subjected to impact by components of the basket catheter 10 or other objects, the coating 27 may be damaged and eventually peel off. Therefore, by forming an opening 55 through the covering 54 and then coating the surface of the electrode 26 with the coating 27, the disclosed technique may also help reduce the possibility of damaging the coating 27 while reducing the overall impedance.

[0071] Herein, we refer to Figure 9, which is a schematic diagram of the elongated deflectable element 12 of the basket catheter 10 in Figures 1A and 1B. The elongated deflectable element 12 can be made from any suitable material, for example, polyurethane or polyether block amide. As shown in Figure 20, the distal end 14 of the elongated deflectable element 12 has a smaller outer diameter than the rest of the elongated deflectable element 12 in order to receive a connector 16 thereon. The elongated deflectable element 12 includes a lumen 66 for inserting various tubes and wires inside, as described herein. The elongated deflectable element 12 can have any suitable outer diameter and length, for example, the outer diameter may be in the range of 1 mm to 4 mm and the length may be in the range of 1 cm to 15 cm.

[0072] Here, we refer to Figure 10, which is a schematic diagram of the irrigation sleeve 72 of the basket catheter 10 in Figures 1A and 1B. The irrigation sleeve 72 is a flexible tube disposed within one of the lumens 66 (Figure 9) of the elongated deflectable element 12 (Figure 9). The irrigation sleeve 72 can be used to deliver irrigation fluid into the area of ​​the expandable assembly 22 (Figures 1A and 1B). As shown in Figure 20, the irrigation sleeve 72 is sized to fit into one of the lumens 66 (typically the central lumen) of the elongated deflectable element 12 and extends beyond the distal end 14 (Figure 9) of the elongated deflectable element 12. The inner and outer diameters of the irrigation sleeve 72 may range from 3 mm to 5 mm. The irrigation sleeve 72 may be formed from any suitable material, not limited to, for example, polyimide, polyurethane, polyether block amide, or polyethylene terephthalate.

[0073] Here, we refer to Figure 11, which is a schematic diagram of the pusher 18 of the basket catheter 10 shown in Figures 1A and 1B. The pusher 18 is a flexible tube and is disposed within the irrigation sleeve 72. The pusher 18 is sized to slide within the irrigation sleeve 72, giving room for the irrigation fluid to pass between the irrigation sleeve 72 and the pusher 18. The inner diameter of the pusher 18 is sized to accommodate the wiring of the multi-axis position sensor as shown with reference to Figure 12. The pusher 18 extends beyond the distal end 14 of the elongated deflectable element 12 (Figure 9) to the nose connector 30 as shown in Figure 19. The pusher 18 may be formed from any suitable material, not limited to, for example, braided or unbraided polyimide, braided or unbraided polyetheretherketone (PEEK), or braided or unbraided polyamide.

[0074] Here, we refer to Figure 12, which is a schematic diagram of the multi-axis position sensor 74 of the basket catheter 10 shown in Figures 1A and 1B. The multi-axis position sensor 74 may include a biaxial or triaxial position sensor, for example, a magnetic position sensor including multiple orthogonal coils. Wiring 76 is used to connect the multi-axis position sensor 74 to a position calculation system (not shown) located proximal to the basket catheter 10, via the hollow of the pusher 18 (Figure 11). The multi-axis position sensor 74 and wiring 76 are shown in detail in Figures 5 and 19.

[0075] Here, we refer to Figures 13A and 13B, schematic diagrams of the nose connector 30 of the basket catheter 10 shown in Figures 1A and 1B. The nose connector 30 may be formed from any suitable material, not limited to, for example, polycarbonate with or without glass fillers, PEEK with or without glass fillers, or PEI with or without glass fillers. The nose connector 30 includes a proximal cavity 78 (Figure 13A) through which a pusher 18 (Figure 11) is fixed and wiring 76 passes, as shown in Figure 19. Figure 13B also shows a distal receiving portion 34, an inner surface 36, and a distally facing opening 38. The distal receiving portion 34 houses a multi-axis position sensor 74 (Figure 12) and a hinge 28 (Figure 5) connected to the inner surface 36.

[0076] Here, we refer to Figure 14, which is a schematic diagram of the central electrode ring 40 of the basket catheter 10 in Figures 1A and 1B. The electrode 40 is electrically connected to a wire (not shown) that passes through a slot on the side of the proximal cavity 78 and enters the pusher 18. The central electrode ring 40 may be formed from any suitable material, not limited to precious metals and alloys thereof, including, for example, platinum, palladium, gold, or iridium. The central electrode ring 40 plays a secondary role by providing mechanical support around the proximal cavity 78 (Figure 13A) of the nose connector 30 in order to secure the nose connector 30 to the pusher 18 (Figure 11), as shown in Figure 19.

[0077] Here, refer to Figures 15A to 15B, schematic diagrams of the nose cap 32 of the basket catheter 10 in Figure 1. The nose cap 32 includes a hollow cylinder 80, which is covered with a covering 82 that may be wider than the hollow cylinder 80. The nose cap 32 may be formed from any suitable material, not limited to, for example, polycarbonate with or without glass fillers, PEEK with or without glass fillers, or PEI with or without glass fillers. The nose cap 32 is sized to fit into the distal receiving portion 34 (Figure 13B) of the nose connector 30 (Figure 13B), as shown in Figure 19, and to cover the distally facing opening 38 (Figure 13B) while allowing space for the multi-axis position sensor 74 (Figure 12) and the hinge 28 (Figure 5) therein. The nose cap 32 may optionally be sized to provide a pressure fit for the hinge 28 to prevent the hinge 28 from being pulled away from the inner surface 36 (Figure 13B) of the nose connector 30 (Figure 13B). The nose connector 30 may also function to protect the multi-axis position sensor 74.

[0078] Herein, we refer to Figure 16, which is a schematic diagram of the connector 16 of the basket catheter 10 in Figures 1A and 1B. The connector 16 typically comprises a hollow tube and may be formed from any suitable material, not limited to polycarbonate with or without glass fillers, PEEK with or without glass fillers, polyimide with or without glass fillers, polyamide, or PEI. The connector 16 may be sized to have the same inner diameter as the outer diameter of the distal end 14 (Figure 9) of the elongated deflectable element 12 (Figure 9), and the same outer diameter as the proximal portion of the elongated deflectable element 12. The connector 16 may also be sized to surround various elements, which will be described in more detail with reference to Figure 20.

[0079] Here, we refer to Figure 17, which is a schematic diagram of the uniaxial position sensor 86 of the basket catheter 10 in Figures 1A and 1B. The uniaxial position sensor 86 may include any suitable position sensor, for example, a magnetic position sensor including a coil wound on a hollow cylinder 88. Wiring (not shown) from the uniaxial position sensor 86 may be routed from one of the lumens 66 (Figure 9) to a position calculation system (not shown) located proximal to the basket catheter 10. The hollow cylinder 88 is sized to accommodate an irrigation sleeve 72 therein, as shown in Figure 20. The outer diameter and length of the uniaxial position sensor 86 are sized to fit into a connector 16 (Figure 16). The hollow cylinder 88 may be formed from any suitable material, not limited to the material used as the magnetic core, for example.

[0080] Here, we refer to Figure 18, which is a schematic diagram of the proximal retaining ring 84 of the basket container 10 in Figures 1A and 1B. The proximal retaining ring 84 is configured to provide a pressure fit around the distal end of the irrigation sleeve 72 (Figure 10), as shown in Figure 20, and to hold the uniaxial position sensor 86 (Figure 17) adjacent to the distal end 14 (Figure 9) of the elongated deflectable element 12 (Figure 9). The proximal retaining ring 84 also serves to secure the flexible polymer circuit 24 between the retaining ring 84 and the connector 16. The proximal retaining ring 84 may be formed from any suitable material, not limited to, for example, polycarbonate with or without glass fillers, PEEK with or without glass fillers, or PEI with or without glass fillers.

[0081] Now, refer to Figures 19-20, which show a cross-sectional view through line AA in Figure 1B. Figure 19 shows the distal portion of the expandable assembly 22, and Figure 20 shows the proximal portion.

[0082] Figure 19 shows that the distal portion 20 of the pusher 18 is positioned within the proximal cavity 78 of the nose connector 30 and secured therein using a central electrode ring 40 positioned around the outside of the proximal cavity 78. The multi-axis position sensor 74 is positioned within the distal receiving portion 34 of the nose connector 30, with wiring 76 extending proximal through the pusher 18. The second end 46 of the flexible polymer circuit strip 24 connects to the inner surface 36 of the distal receiving portion 34 of the nose connector 30. An elongated elastic support element 48 extends along the length of the flexible polymer circuit strip 24 to a hinge 28, but does not include the hinge 28. The nose cap 32 is inserted into the distal receiving portion 34 such that the hollow cylinder 80 surrounds the distal portion of the multi-axis position sensor 74 and provides pressure to the second end 46 of the flexible polymer circuit strip 24. The nose cap 32 covers the distally facing opening 38 of the nose connector 30.

[0083] Figure 20 shows that the irrigation sleeve 72 is housed within the elongated deflectable element 12. The pusher 18 is housed within the irrigation sleeve 72. The wiring 76 is housed within the pusher 18. The uniaxial position sensor 86 is housed around the irrigation sleeve 72 near the distal end 14 of the elongated deflectable element 12 (between the connector 16 and the pusher 18). The proximal retaining ring 84 provides a pressure fit around the irrigation sleeve 72, holding the uniaxial position sensor 86 distal to the distal end 14 of the elongated deflectable element 12. The proximal end of the connector 16 is connected to the distal end 14 of the elongated deflectable element 12. The first end 42 of the flexible polymer circuit strip 24 is connected to the inner surface 44 of the connector 16. Figure 20 shows that the elongated elastic support elements 48 extend from the connector 16 along each strip 24 up to the front of each hinge 28 (Figure 19).

[0084] Figure 21 shows another diagram of the catheter 10 with annotations indicating various features of the catheter 10. For example, Figure 21 shows that the expandable assembly 22 may be sized to expand to a diameter of approximately 18 mm, and may include 10 spines 24 (100 electrodes 26 in total), each having 10 electrodes 26, and approximately 0.2 mm spaced 1.7 mm apart. 2 This indicates that it has a small outward-facing electrode, includes an internal central "TruRef" electrode (reference electrode 31), the approximate locations of the first and second position sensors 74, and that the elongated deflectable element 12 is about 8 French sizes and may be deflectable in both directions.

[0085] Figure 22 shows a rendering of the basket catheter 10 on a display showing the basket in an expanded and folded state. As shown in the figure, the basket catheter 10 is graphically displayed using various colors and annotations to show various orientations and specific spines, which may help to show the orientation of the catheter 10 in the patient's heart to the physician 5.

[0086] Although the expandable assembly 22 is shown without being mounted on a flexible membrane, it is within the scope of the invention that the expandable assembly may comprise a membrane (e.g., a balloon-like surface) as the base material for the circuit strip. Similarly, the membrane may be used as a coating layer on the circuit strip 24 when the electrode 26 is exposed to the surrounding environment (e.g., within organ tissue) (or not covered by the membrane for exposure).

[0087] Method and Test Description This disclosure is better understood by the corresponding tests and methods described herein. The data are presented herein for illustrative purposes only and should not be construed as limiting the scope of the disclosed technology in any way, or excluding any alternative or additional embodiments.

[0088] The aforementioned catheter 10 was tested by physicians in a promising single-arm, multicenter trial including patients undergoing catheter mapping and ablation for atrial and ventricular arrhythmias. Mapping was performed using the test catheter 10, and participants underwent ablation according to the investigator's standard of care. The primary efficacy endpoint was completion of pre-ablation electroanatomical mapping without relying on a non-test catheter. The primary safety endpoint was the incidence of device-related serious adverse events (SAEs) within 7 days. Physician feedback on catheter performance was collected via a 7-point Likert scale.

[0089] As part of the trial, 40 participants (mean age 58.0 ± 15.73 years, 62.5% male, 30 with atrial arrhythmias, 10 with ventricular arrhythmias) underwent mapping using the study catheter. The primary efficacy endpoint was achieved in all 40 participants. Regions of interest with ≥1 for mappable rhythms were identified in 23 out of 30 participants with atrial arrhythmias. During pre-ablation mapping, only one SAE of transient complete atrioventricular block was reported in patients with persistent atrial fibrillation, and it resolved completely. Physician feedback indicated that the device met or exceeded expectations in signal quality. Most respondents gave high ratings to bipolar signal quality in the atria and to the murmurs encountered.

[0090] In this first-in-human clinical trial, the research-grade ultra-high density spherical catheter achieved its primary safety and efficacy endpoints, demonstrating a favorable acute safety and efficacy profile for mapping complex arrhythmias. Its deflectable shaft and variable basket deployment allowed the catheter to access all cardiac chambers. For all study procedures, pre-ablation mapping required by the protocol was completed with the study catheter without the need to switch to a separate mapping catheter. The safety profile of the study catheter was comparable to that experienced with other commercially available high-density mapping catheters used for atrial and ventricular procedures. Only one SAE within 7 days of the index procedure was considered related to the study catheter; three procedure-related SAEs were not catheter-related, while one non-serious AE was considered related to the study catheter. For all events, participants recovered fully and were discharged within 7 days post-procedure. The mean pre-ablation mapping times were 23.8 minutes, 21.6 minutes, 26.8 minutes, 5.4 minutes, and 17.9 minutes for participants with AT / AFL, PsAF, PAF, VT, and PVC, respectively.

[0091] Like other high-density mapping catheters, the research catheter detected PVI breakthroughs and triggers. The design of the research catheter facilitated the rapid identification of mechanisms that sustain arrhythmias, improving the procedure workflow and efficiency. The presence of three magnetic sensors embedded in the distal and proximal portions of the sphere, which transmit information to the CARTO®3 system, allowed visualization of the basket in open or closed configurations. In addition, catheter position and angle information could be transmitted to the CARTO®3 system independently of the advanced catheter position. Furthermore, the combination of an increased number of close-proximity small flat electrodes and an internal TRUEref reference electrode provided higher density mapping with high intracardiac signal resolution. The experience in this study is based on preclinical observations that the TRUEref electrode was able to filter and remove far-field ventricular signals during atrial mapping and around block lines, reducing inaccurate timing annotations. The wisdom of the crowd algorithm was implemented at 1 mm 3 Based on specific criteria collected within a predefined FAM region (voxel), we were able to reduce outliers, which are misannotated LAT points.

[0092] Overall, operators assessed the research catheter as equivalent to or better than the PENTARAY® catheter in confirming PVI, its proarrhythmic properties, and histological characterization. However, this trial was limited by the small sample size of participants dispersed across different arrhythmia subgroups. It would have been desirable to enroll participants with the most common arrhythmia mechanisms rather than a wide range of arrhythmias. Ideally, a higher proportion of ischemic VT cases would allow for a more complete evaluation of the research catheter, and more trials with longer follow-up periods would be better indicators of efficacy. CARTO® V7 was the latest CARTO® version available at the time of this trial. Other unique features designed to leverage the spherical design of the research catheter were not yet available during the trial period.

[0093] Test evaluation items The primary efficacy endpoint was the completion of the protocol-required electroanatomical ablation premapping without relying on a non-test mapping catheter. The primary safety endpoint was the incidence of device-related serious adverse events (SAEs) within 7 days post-procedure.

[0094] Secondary efficacy endpoints included the atrial and ventricular deployment characteristics, operability, and signal quality of the study catheter, based on physician feedback from post-procedure questionnaires. Questionnaires were collected after each study procedure for each study catheter used and included Likert scale response options for operability and handling, signal acquisition and quality, pacing, catheter design, workflow, visualization, catheter interaction, proarrhythmics, design and effective range for confirming PVI, and the ability to characterize tissue. A score of "4" on a 7-point scale was considered comparable to other devices. Secondary safety endpoints included the incidence of SAEs (excluding SAEs related to the study catheter) within 7 days of the benchmark procedure, and the incidence of non-serious adverse events (AEs) related to the study catheter within 7 days of the benchmark procedure.

[0095] Additional procedure characteristics included total procedure time, initial mapping duration (time between the first and last mapping points prior to the first ablation point, as measured on CARTO), captured regions of interest (e.g., PV triggers, previous PVI lesion gaps, slow conduction scar zones, critical isthmuses, etc.), and mapping density.

[0096] Arrhythmia mapping was evaluated as an additional endpoint. The period length of atrial tachycardia (AT) was determined using atrial criteria. For atrial flutter (AFL) or focal AT, the window was adjusted to include the entire atrial period length or the point before the P wave, and automatic point acquisition (CONFIDENSE) was set to the discretion of the individual operator. The period of ventricular tachycardia (VT) or mapping of premature ventricular complexes (PVCs) was determined using ventricular criteria. The window was adjusted for sustained VT or PVC, each to include the entire ventricular period length or the point before the QRS wave, and automatic point acquisition (CONFIDENSE) was set to the discretion of the operator.

[0097] Exam Description Eligible participants were scheduled to undergo clinically indicated catheter mapping and ablation procedures for VT, PVC, AT, AFL, or paroxysmal or persistent atrial fibrillation (PAF or PsAF), and could include patients who had previously undergone ablation. Exclusion criteria included diagnosis of arrhythmias requiring epicardial mapping, left ventricular ejection fraction (LVEF) ≤25% for patients with VT, and LVEF ≤40% for patients with atrial arrhythmias.

[0098] Pre-procedure evaluation and data collection included baseline medical history, cardiac history, arrhythmia history and ablation history, transthoracic echocardiography, pregnancy testing, thrombosis screening, collection of optional adverse events after registration, and subsequent ablation in accordance with the institution's standard of care (SOC).

[0099] Figures 23A and 23B illustrate further details of inclusion and exclusion criteria for patients as part of a catheterization trial, according to an example of the present invention. As illustrated, participants in the trial must qualify for the trial by meeting various requirements, including being scheduled to undergo clinically directed catheter mapping and ablation procedures for the management of arrhythmias in subgroups including scar-related atrial tachycardia (AT), persistent atrial fibrillation (PsAF), paroxysmal atrial fibrillation (PAF), ventricular tachycardia (VT), or ventricular premature contractions (PVCs) (2302). If a patient meets this first requirement, the patient must also be diagnosed with AT, PsAF, PAF, VT, or PVC (2304) and be a candidate for clinically directed catheter mapping and ablation procedures for the management of these conditions.

[0100] To be included in the trial, patients must also have had at least one episode of target arrhythmia recorded by ECG, Holter, loop recorder, telemetry, implantable device, or telephone monitoring within 12 months of enrollment (2306), be 18 years of age or older (2308), sign a patient informed consent form (2310), and be able to and willing to comply with all pre-, post-, and follow-up examinations and requirements (2312). The trial included 40 participants.

[0101] Participants were excluded from the study if any of the following criteria were met (2314): the patient was under 18 years of age, diagnosed with an arrhythmia requiring epicardial mapping, the arrhythmia in study was secondary to a reversible cause or to an electrolyte imbalance, thyroid disease, or noncardiac cause, atrial arrhythmia: left atrial size >55 mm, LVEF ≤25% for ventricular arrhythmias, LVEF ≤40% for atrial arrhythmias, research Patients with a record of detecting intracardiac thrombus by imaging within 24 hours prior to catheter insertion; contraindications to anticoagulant therapy (i.e., heparin, warfarin, dabigatran); a history of thrombosis or bleeding abnormalities (e.g., hypercoagulability); myocardial infarction within the past 2 months (60 days); a recorded thromboembolic event (including TIA) within the past 12 months (365 days); uncontrolled heart failure or NYHA functional class IV; or a pacemaker or intracardiac defibrillator within the past 6 weeks (42 days). Patients with implanted kinetic devices, known incurable allergies to contrast agents, active disease or active systemic infection or sepsis, diagnosed with atrial or ventricular myxoma, tumors or other abnormalities interfering with interatrial baffles or patches, catheter insertion or manipulation, significant congenital abnormalities or medical problems in the opinion of the principal investigator that would prevent enrollment in this study, subjects with a history of percutaneous or surgical cardiac valve procedures (i.e., ventricular incision, atrial incision, and valve repair or replacement, and the presence of prosthetic valves), cardiac surgery (including PCI) within the past 60 days (2 months), atrial septal closure within the past 6 weeks (42 days), the presence of conditions that impede vascular access, pregnant (confirmed by pregnancy test if premenopausal), lactating, or of childbearing age planning to become pregnant during the course of the clinical trial, patients classified as vulnerable populations requiring special consideration regarding the protection of their welfare, or concurrent enrollment in a clinical trial evaluating another device or drug. If a patient met any of the above criteria, that patient was not included in the study.

[0102] Figure 24 is a table showing baseline attributes and comorbidities of participants enrolled in the study according to an example of the present invention. A total of 40 participants completed the study procedure. The mean age of the participants was 58.0 years, and 25 (62.5%) were male. Most participants (38 / 40, 95.0%) did not have structural heart disease. Approximately two-thirds did not have heart failure (27 / 40, 67.5%), but nine participants (22.5%) had NYHA class I heart failure, and two participants (5.0%) had NYHA class II heart failure. Of the 30 participants with atrial arrhythmias (7 with AFL, 2 with AT, 7 with PsAF, and 14 with PAF), 16 participants (53.3%) had a history of ≥1 previous ablation procedure performed for the treatment of AF (15 participants), typical AFL (5 participants), AT (2 participants), or atypical AFL (2 participants). These conventional ablation procedures were performed using radiofrequency (14 procedures), cryoablation (1 procedure), and other ablation techniques (2 procedures). Of the 10 participants with ventricular arrhythmias (1 with VT and 9 with PVC), two participants underwent prior ablation using radiofrequency catheters for the treatment of AF (1 patient) and PVC (1 patient).

[0103] Figures 25A and 25B are tables showing the history of atrial and ventricular arrhythmias and ablation procedures of participants registered in a study, according to an example of the present invention.

[0104] All participants (40 / 40, 100%) completed the pre-ablation mapping required by the protocol using research catheters. The entire target cardiac chamber targeted for arrhythmia mapping was completed using FAM. No other non-experimental mapping catheters were used for any pre-ablation mapping.

[0105] Research catheters were used only for all pre-ablation mapping procedures. The catheter was advanced into the target cardiac chamber via any commercially available 8.5Fr sheath, and mapping was performed using automatic point acquisition (CONFIDENSE) for each pulse restricted to respiration and cardiac cycle. Pre-ablation mapping included FAM of the entire cardiac chamber and regions associated with the target arrhythmia. Electroanatomical mapping was performed to determine substrate voltage or tachycardic excitation mechanism, local activation timing (LAT), identify conduction channels, gaps and critical isthmuses, and determine an appropriate level of mapping density in the region of interest. Research catheters were used with continuous irrigation and activation clotting time ≥300 seconds. Heparinized saline (1 unit / mL) was injected at a rate of 2 mL / min through the central lumen of the catheter shaft and brought to the end of the shaft (proximal end of the basket) to prevent thrombosis.

[0106] Following mapping, ablation procedures were performed according to the institution's standard treatment guidelines. If additional mapping was clinically indicated after ablation, a research catheter was used. Phrenic nerve pacing was frequently performed during catheter ablation to assess any nerve damage caused by the ablation catheter. The ability of the research catheter to perform phrenic nerve pacing or pacing capture was examined. The follow-up period was 7 days, including telephone or in-person visits to assess adverse events (AEs).

[0107] Figure 26 is a table of treatment characteristics for procedures completed as part of a trial according to an example of the present invention. For atrial procedures, the mean total treatment duration was 131.4 minutes (141.1 minutes for participants with AT / AFL, 138.0 minutes for participants with PsAF, and 122.0 minutes for participants with PAF), while the mean total pre-ablation mapping time was 24.7 minutes (23.8 minutes for participants with AT / AFL, 21.6 minutes for participants with PsAF, and 26.8 minutes for participants with PAF). For ventricular procedures, the mean total treatment duration was 116.7 minutes (219.0 minutes for one patient with VT and 105.3 minutes for the PVC participant), while the mean total pre-ablation mapping time was 16.7 minutes (5.4 minutes for the patient with VT and 17.9 minutes for the participant with PVC) (Figure 26).

[0108] FAM maps were created for all participants, and voltage maps were created for all 30 atrial procedures and 8 / 10 ventricular procedures. In addition, LAT maps were created for 25 / 30 atrial procedures and 7 / 10 ventricular procedures. Study catheters were used for phrenic nerve pacing in 5 participants, and local pacing capture was demonstrated in all of these procedures. Phrenic nerve stimulation was not performed in any of the procedures. In addition, post-SOC mapping was performed in 30 / 40 participants (75.0%).

[0109] No embolic events were reported. At the end of the procedure, the catheter was examined, and no visible thrombi, device malfunction, or entanglement of cardiac structures were reported.

[0110] FAM and voltage mapping were completed for all 30 atrial arrhythmia procedures. LAT mapping was performed for 83.3% (25 / 30) of participants, including all 9 participants with focal AT / AFL procedures (100%), 11 / 14 participants with PAF procedures (78.6%), and 5 / 7 participants with PsAF procedures (71.4%). FAM mapping was also created for 100% (10 / 10) of participants with ventricular tachycardia. Voltage mapping was performed for 80.0% (8 / 10) of subjects, and LAT was performed for 70.0% (7 / 10) of participants.

[0111] Figures 27A–27D show graphic representations of atypical flutter time (LAT) and voltage (bipolar) maps of the left atrium of a patient's heart using a catheter, according to an example of the present invention. In some of the images in Figures 27A–27D, the wave propagation paths are annotated on the image. The entire tachycardia cycle length (approximately 240 ms) was mapped and the circuit was identified. Low-voltage or scar tissue areas were also defined with adjusted voltage cutoffs (<0.1 mV in red and >0.5 mV in purple). As shown in Figures 27A–27D, the location and timing of electrophysiological signals propagating through the tissue can be mapped and displayed on a screen to help the physician locate the ablation site.

[0112] High-density LAT mapping helped identify and visualize atypical tachycardia mechanisms. TRUEref® electrodes (reference electrode 31) on the catheter allowed the operator to acquire points with clearer signal quality, thus annotating the signals with the correct near-field components instead of far-field components. Furthermore, a crowd wisdom algorithm effectively and automatically reduced outlier LAT annotations based on the density of data collected within 1 mm³ voxels (see Figures 27A–27D).

[0113] The disclosed techniques may include the ability to filter electrophysiological signals to better identify and display locations of interest. For example, coloring and tolerances may be adjusted (e.g., via a toggle switch or manual change to a software setting) to better highlight the focus and surrounding region of the arrhythmia that the physician wishes to ablate. As described in more detail herein, the disclosed techniques may include a method for identifying and highlighting locations where the excitation time is within a predetermined duration (e.g., less than 1 second, less than 10 milliseconds, less than 1 millisecond) from the earliest excitation of an identified earliest excitation point. In other examples, further filters (or alternative filters) may include distance from the earliest excitation point (e.g., less than 20 millimeters, less than 10 millimeters, less than 5 millimeters, less than 1 millimeter). In this way, a more accurate map can be generated and displayed for the physician to identify locations to be ablated. The time and distance from the earliest excitation point may be modified by the physician to identify locations for ablation, depending on the type of arrhythmia or other abnormal condition identified.

[0114] As one non-limiting example, the disclosed technology may include the ability to cause a physician to configure map data such that any location where the excitation time is within a predetermined time (e.g., less than 1 second, less than 10 milliseconds, less than 1 millisecond) and / or within a predetermined distance (e.g., less than 20 millimeters, less than 10 millimeters, less than 5 millimeters, less than 1 millimeter) is indicated by a first color (e.g., red), and all other locations are indicated by a second color (e.g., purple).

[0115] Figures 28A and 28B show intracardiac electrocardiogram recordings of a patient's heart observed by catheter, according to an example of the present invention. Far-field ventricular signals are filtered during atrial tachycardia mapping and around block lines to reduce erroneous annotations.

[0116] The acquired points were automatically annotated with the sharpest and largest negative deflection (-dV / dt), depicting the earliest pre-P wave intracardiac atrial signal with sharp downstrokes of the QS complex and focal AT. While the earliest PV breakthrough sites were targeted to achieve venous isolation, 23 / 30 AT participants (76.7%) had one or more regions of interest identified by the research catheter, including PV and non-PV triggers, PVI breakthroughs, left atrial flutter critical isthmus, or CTI.

[0117] Figure 29 shows a graphical representation of a catheter positioned within a patient's heart to complete a mapping procedure according to an example of the present invention. As shown, a pulmonary vein breakthrough was identified and mapped in the right anterior PV using a research catheter.

[0118] Figure 30 shows a graphical representation of a catheter positioned in a patient's heart, indicating a localized atrial tachycardia site pre-QS P wave mapped and identified in the anterior left prominence region, according to an example of the present invention. As shown, the earliest localized atrial tachycardia site pre-QS P wave was mapped and identified in the anterior left prominence region.

[0119] Figure 31 is a table summarizing regions of interest identified using a catheter in participants with atrial tachycardia, including PVI triggers, PVI breakthroughs, non-PVAF lesions, left atrial critical isthmus, and inferior vena cava tricuspid isthmus, according to an example of the present invention.

[0120] Furthermore, Figure 32 shows a PVC map with the earliest QS pre-QRS site identified in a septal RVOT using a catheter, according to an example of the present invention, and Figure 33 shows the region and surrounding area of ​​the earliest excitation time position with a predetermined duration less than a given duration, calculated and compared to the map's baseline. Points were automatically annotated for the sharpest and largest negative deflection (-dV / dt) and defined the boundary of the earliest intracardiac QRS preventricular signal with a sharp downstroke for the QS complex and PVC. Since most of the ventricular cases were PVCs and not ischemic VT, it was not feasible to identify conduction channels, gaps, critical isthmus, and delayed potentials. However, the research catheter identified the earliest point of excitation within a given time (e.g., 10 ms) for all nine PVC procedures, and 1.08 cm 2 We were able to summarize it into an average area.

[0121] Figure 34 is a table summarizing all PVC cases, identifying the earliest point from the intermediate QRS (reference), the earliest point before the QRS, the region of the earliest predetermined duration excitation point (e.g., 10 milliseconds), and the area around the earliest 10 millisecond point, according to an example of the present invention.

[0122] Method explanation Figure 35 shows a flowchart of a catheter-based method 3500 according to an example of the present invention. As shown, method 3500 may include identifying the earliest excitation point (3505) based on electrophysiological data collected by the catheter (catheter 10). Identifying the earliest excitation point (3505) may be based on both electrophysiological data collected by the electrode 26 and the reference electrode 31, and positional data collected by the position sensor 74. Method 3500 may further include searching for a plurality (e.g., three) nearest mapping points having excitation times less than or equal to a predetermined duration (e.g., less than 1 second, less than 10 milliseconds, less than 1 millisecond) from the earliest excitation time (3510), creating circumferential zones using several concentric circles having radii within a predetermined distance (e.g., less than 20 millimeters, less than 10 millimeters, less than 5 millimeters, less than 1 millimeter) from the earliest excitation point (3520), and dividing each concentric zone into three parts.

[0123] Method 3500 may further include searching for the next point in the concentric zone if a given point is less than a predetermined duration from the earliest excitation time at the earliest excitation point (3530). Alternatively, if a given point is greater than a predetermined duration from the earliest excitation time at the earliest excitation point, the search is terminated using a previously identified point (3540).

[0124] Once all multiple points at the boundary of the earliest point are identified, method 3500 may further include constructing a contour around the multiple points and all points between them that are within a predetermined time from the earliest excitation time at the earliest excitation point (3550). The method may further include outputting the results to a display so that a physician can observe the recorded data.

[0125] As can be understood, the method 3500 described herein may help to more accurately pinpoint the location of the tissue to be ablated. Furthermore, as previously stated, the disclosed technique may include features that allow physicians to modify the settings according to their preferred method and the type of arrhythmia identified, thereby changing the time and distance from the earliest excitation point to more accurately pinpoint the location of ablation for a given scenario.

[0126] Figure 36 schematically illustrates a catheter-based method according to an example of the present invention. Mapping points can be identified by measuring electrophysiological signals at various electrodes 26 (in this example, three electrodes 26 are shown). Bipolarity can be determined between each of the electrodes 26, and mapping points can be identified between multiple electrodes 26. In this way, a more accurate representation of electrophysiological data can be obtained and displayed to the physician. For example, by using two or more electrodes 26, and by setting bipolarity between multiple electrodes 26, inaccuracies due to the direction of wave propagation can be reduced.

[0127] The technologies disclosed herein may be further understood in accordance with the following provisions.

[0128] Clause 1: A method comprising navigating a medical probe to a target location within a patient's heart, wherein the medical probe comprises a plurality of spines extending along a longitudinal axis and configured to bend radially outward from the longitudinal axis, each spine comprising a plurality of electrodes disposed thereon and at least one position sensor disposed on the longitudinal axis, the position sensor configured to provide a position signal representing the position of the sensor and the medical probe within the heart; receiving electrophysiological signals from at least some of the electrodes; identifying an early excitation point identified as having the earliest excitation time based on the electrophysiological signals and position signals; identifying a plurality of points closest to the early excitation point having an excitation time less than a predetermined duration from the earliest excitation time based on the electrophysiological signals and position signals; and generating an electroanatomical map of the heart based on data corresponding to the plurality of points, wherein the electroanatomical map represents the location of the early excitation point for subsequent ablation.

[0129] Clause 2: The method according to Clause 1, further comprising defining a circumferential zone using multiple concentric circles having a radius of less than 10 millimeters from the earliest point of excitation.

[0130] Clause 3: The method according to Clause 2, further comprising dividing each concentric circle into three parts.

[0131] Clause 4: The method according to Clause 2, wherein the radius is less than 7.5 millimeters from the earliest excitation point.

[0132] Clause 5: The method according to Clause 2, wherein the radius is less than 5 millimeters from the earliest point of excitation.

[0133] Clause 6: The method according to Clause 2, wherein the radius is less than 2.5 millimeters from the earliest excitation point.

[0134] Clause 7: The method according to Clause 2, wherein the radius is approximately 1 millimeter from the earliest point of excitation.

[0135] Clause 8: The method of any one of Clauses 2 to 7, further comprising identifying additional points within the concentric circles having an excitation time less than a predetermined duration from the earliest excitation time, if one of the concentric circles has an excitation time less than a predetermined duration from the earliest excitation time.

[0136] Clause 9: The method of any one of Clauses 2 to 7, further comprising using the previous point used to define each concentric circle if each of the concentric circles has an excitation time exceeding a predetermined duration from the earliest excitation time.

[0137] Clause 10: The method of Clause 8 or 9, further comprising defining a region based on a plurality of points and any point between the plurality of points including an excitation time from the earliest excitation time to an excitation time less than a predetermined duration.

[0138] Clause 11: Multiple points are those described in any one of Clauses 1 to 10, including at least three points.

[0139] Clause 12: Multiple points include exactly three points as described in any one of Clauses 1 through 11.

[0140] Clause 13: The method according to any one of Clauses 1 to 12, wherein the plurality of spines comprises 10 spines, and each of the plurality of spines comprises 10 electrodes.

[0141] Clause 14: The method according to any one of Clauses 1 to 13, wherein the electrodes are arranged along a flexible printed circuit on each of the spines of a plurality of spines.

[0142] Clause 15: The method according to any one of Clauses 1 to 14, wherein each of the multiple electrodes is coated with an impedance-reducing coating.

[0143] Clause 16: The method according to any one of Clauses 1 to 15, further comprising an actuator configured to flex the spine radially outward to define a basket having a diameter adjustable from about 3 mm to 18 mm.

[0144] Clause 17: The method according to Clause 16, wherein the electrodes are configured to receive electrophysiological data regardless of the diameter size of the basket.

[0145] Clause 18: The method described in any one of Clauses 1 to 17, which includes generating an electroanatomical map having a resolution of at least 924 points per minute.

[0146] Clause 19: The map shall have a resolution of approximately 1496 points / minute, as described in Clause 18.

[0147] Clause 20: The method according to any one of Clauses 1 to 19, further comprising a reference electrode disposed in a cavity defined by a plurality of spines.

[0148] Clause 21: The method according to Clause 20, wherein the reference electrode is configured to receive electrophysiological data used to reduce far-field signal components.

[0149] Clause 22: The method according to any one of Clauses 1 to 21, wherein at least one position sensor comprises a first magnetic sensor disposed at the distal end of a plurality of spines and a second magnetic sensor disposed at the proximal end of a plurality of spines.

[0150] Clause 23: The method according to any one of Clauses 1 to 22, wherein the medical probe further comprises one or more position-sensing electrodes disposed on the shaft of the medical probe, the one or more position-sensing electrodes configured for impedance-based position sensing.

[0151] Clause 24: The method according to any one of Clauses 1 to 23, wherein the primary safety endpoint of the method is that no one or more serious adverse events occur within seven days of generating the electroanatomical map, and a serious adverse event is any event that leads to death, life-threatening illness or injury, permanent impairment of a body structure or function, hospitalization or extension of an existing hospitalization, medical or surgical intervention to prevent life-threatening illness or injury or permanent impairment of a body structure or function, chronic disease, or fetal distress, fetal death, or birth defects.

[0152] Clause 25: The specified duration is the method described in any one of Clauses 1 to 24, including a duration of 1 second or less.

[0153] Clause 26: The specified duration is the method described in any one of Clauses 1 to 24, including a duration of 10 milliseconds or less.

[0154] Clause 27: The specified duration is the method described in any one of Clauses 1 to 24, including a duration of 5 milliseconds or less.

[0155] Clause 28: The specified duration is any method described in any of Clauses 1 to 24, including 1 millisecond or less.

[0156] Clause 29: A medical system comprising a medical probe, a shaft extending along a longitudinal axis, a plurality of spines disposed at the distal end of the shaft, each spine deflecting radially outward from the longitudinal axis and configured to define a cavity between the plurality of spines, a position sensor disposed on the longitudinal axis and configured to provide a position signal representing the position of the sensor and the medical probe within the heart, a plurality of electrodes disposed along the plurality of spines, and a reference electrode disposed within the cavity, one or more processors, and a memory for storing instructions, the instructions being processed by one or more processors A medical system configured to perform the following when executed by a medical system: receiving electrophysiological signals from at least some of a plurality of electrodes; identifying the earliest excitation point identified as having the earliest excitation time based on the electrophysiological signals and position signals; identifying a plurality of points closest to the earliest excitation point, having an excitation time less than a predetermined duration from the earliest excitation time based on the electrophysiological signals and position signals; and generating an electroanatomical map of the heart based on data corresponding to the plurality of points, wherein the electroanatomical map represents the location of the earliest excitation point for subsequent ablation.

[0157] Clause 30: The medical system as described in Clause 29, wherein the instruction, when executed by one or more processors, is further configured to cause the medical system to define a circumferential zone using multiple concentric circles having a radius of less than 10 millimeters from the earliest point of excitation.

[0158] Clause 31: The medical system described in Clause 30, wherein the instructions, when executed by one or more processors, are further configured to divide each concentric circle into three.

[0159] Clause 32: The medical system described in Clause 30, where the radius is less than 7.5 millimeters from the earliest point of excitation.

[0160] Clause 33: The medical system described in Clause 30, where the radius is less than 5 millimeters from the earliest point of excitation.

[0161] Clause 34: The medical system described in Clause 30, where the radius is less than 2.5 millimeters from the earliest point of excitation.

[0162] Clause 35: The medical system described in Clause 30, where the radius is approximately 1 millimeter from the earliest point of excitation.

[0163] Clause 36: The medical system according to any one of Clauses 30 to 35, wherein, when executed by one or more processors, the instruction is further configured to cause the medical system to identify additional points within a concentric circle having an excitation time of less than 10 milliseconds from the earliest excitation time, if one of the concentric circles has an excitation time less than a predetermined duration from the earliest excitation time.

[0164] Clause 37: The medical system according to any one of Clauses 30 to 36, wherein, when an instruction is executed by one or more processors, the medical system is further configured to cause the medical system to use the previous point used to define each concentric circle if each of the concentric circles has an excitation time greater than a predetermined duration from the earliest excitation time.

[0165] Clause 38: The medical system according to Clause 36 or 37, wherein the instructions, when executed by one or more processors, are further configured to cause the medical system to define a region based on a plurality of points and any point among the plurality of points including an excitation time from the earliest excitation time to an excitation time less than a predetermined duration.

[0166] Clause 39: A healthcare system described in any one of Clauses 29-38, wherein multiple points include at least three points.

[0167] Clause 40: A healthcare system described in any one of Clauses 29-39, where multiple points include exactly three points.

[0168] Clause 41: A medical system according to any one of Clauses 29 to 40, wherein the multiple spines include 10 spines, and each of the multiple spines includes 10 electrodes.

[0169] Clause 42: A medical system according to any one of Clauses 29 to 41, wherein electrodes are arranged along a flexible printed circuit on each of the spines of a plurality of spines.

[0170] Clause 43: A medical system as described in any one of Clauses 29 to 42, in which each of the multiple electrodes is coated with an impedance-reducing coating.

[0171] Clause 44: A medical system according to any one of Clauses 29 to 43, further comprising an actuator configured to flex the spine radially outward to define a basket having a diameter adjustable from approximately 3 mm to 18 mm.

[0172] Clause 45: The medical system as described in Clause 44, wherein the electrodes are configured to receive electrophysiological data regardless of the diameter size of the basket.

[0173] Clause 46: A medical system described in any one of Clauses 29 to 45, which generates an electroanatomical map, which includes generating a map having a resolution of at least 924 points / minute.

[0174] Clause 47: The map shall have a resolution of approximately 1496 points / minute, as described in Clause 46.

[0175] Clause 48: A medical system according to any one of Clauses 29 to 47, further comprising a medical probe and a reference electrode disposed within a cavity defined by multiple spines.

[0176] Clause 49: A medical system as described in Clause 48, wherein the reference electrode is configured to receive electrophysiological data used to reduce far-field signal components.

[0177] Clause 50: A medical system according to any one of Clauses 29 to 49, further comprising: a medical probe, a first magnetic sensor disposed at the distal end of a plurality of spines; and a second magnetic sensor disposed at the proximal end of a plurality of spines.

[0178] Clause 51: A medical probe further comprising one or more electrodes arranged on a shaft, configured for impedance-based position detection, as described in any one of Clauses 29 to 50 of the medical system.

[0179] Clause 52: A medical system as described in any one of Clauses 29 to 51, where the specified duration includes one second or less.

[0180] Clause 53: A medical system as described in any one of Clauses 29 to 51, with a specified duration of 10 milliseconds or less.

[0181] Clause 54: A medical system as described in any one of Clauses 29 to 51, with a specified duration including 5 milliseconds or less.

[0182] Clause 55: A medical system as described in any one of Clauses 29 to 51, with a specified duration including 1 millisecond or less.

[0183] The embodiments described above are for illustrative purposes only, and the present invention is not limited to those specifically illustrated and described herein. Rather, the scope of the present invention includes both combinations and partial combinations of the various features described and illustrated herein, as well as variations and modifications thereof not disclosed in the prior art, which will be recalled by those skilled in the art by reading the foregoing description.

[0184] [Implementation Method] (1) A method, Navigating a medical probe to a target location within a patient's heart, wherein the medical probe comprises a plurality of spines extending along a longitudinal axis and configured to bend radially outward from the longitudinal axis, the plurality of spines comprising a plurality of electrodes disposed on the plurality of spines and at least one position sensor disposed on the longitudinal axis, the position sensor configured to provide a position signal representing the position of the sensor and the medical probe within the heart, Receiving electrophysiological signals from at least some of the electrodes among the plurality of electrodes, Based on the electrophysiological signal and the position signal, the earliest excitation point identified as having the earliest excitation time is identified, Based on the electrophysiological signal and the position signal, identify a plurality of points closest to the earliest excitation point, having an excitation time less than a predetermined duration from the earliest excitation time. A method comprising generating an electroanatomical map of the heart based on data corresponding to the aforementioned plurality of points, wherein the electroanatomical map represents the location of the earliest excitation points for subsequent ablation. (2) The method according to Embodiment 1, further comprising defining a circumferential zone using a plurality of concentric circles having a radius of less than 10 millimeters from the earliest excitation point. (3) The method according to Embodiment 2, further comprising dividing each concentric circle into three parts. (4) The method of Embodiment 2, further comprising identifying additional points within the concentric circle having an excitation time less than the predetermined duration from the earliest excitation time, if one of the plurality of concentric circles includes a point having an excitation time less than the predetermined duration from the earliest excitation time. (5) The method of Embodiment 2, further comprising using a previous point used to define each of the concentric circles if each of the plurality of concentric circles includes a point having an excitation time from the earliest excitation time to the predetermined duration.

[0185] (6) The method of Embodiment 2, further comprising defining a region based on the plurality of points and any point between the plurality of points including an excitation time from the earliest excitation time to an excitation time less than the predetermined duration. (7) The method according to Embodiment 6, wherein the plurality of points include at least three points. (8) The method according to Embodiment 1, wherein the plurality of spines comprises 10 spines, and each of the plurality of spines comprises 10 electrodes. (9) The method according to Embodiment 1, wherein the electrodes are arranged along a flexible printed circuit on each of the spines among the plurality of spines. (10) The method according to Embodiment 1, wherein each of the plurality of electrodes is coated with an impedance-reducing coating.

[0186] (11) The method according to Embodiment 1, wherein the medical probe further comprises an actuator configured to deflect the spine radially outward to define a basket having a diameter adjustable from about 3 mm to 18 mm. (12) The method according to Embodiment 1, wherein generating the electroanatomical map includes generating a map having a resolution of at least 924 points / minute. (13) The method according to Embodiment 1, wherein the medical probe further comprises a reference electrode disposed in a cavity defined by the plurality of spines. (14) The method according to embodiment 13, wherein the reference electrode is configured to receive electrophysiological data used to reduce far-field signal components. (15) The method according to Embodiment 1, wherein the at least one position sensor comprises a first magnetic sensor disposed at the distal end of the plurality of spines and a second magnetic sensor disposed at the proximal end of the plurality of spines.

[0187] (16) The method according to Embodiment 1, wherein the medical probe further comprises one or more position-sensing electrodes disposed on the shaft of the medical probe, and the one or more position-sensing electrodes are configured for impedance-based position detection. (17) The method according to Embodiment 1, wherein the predetermined duration is 10 milliseconds or less. (18) A medical system, A medical probe, A shaft extending along the longitudinal axis, A plurality of spines disposed at the distal end of the shaft, which are configured to deflect radially outward from the longitudinal axis and define a cavity between the plurality of spines, A position sensor disposed on the longitudinal axis, configured to provide a position signal representing the position of the sensor and the medical probe within the heart, Multiple electrodes arranged along the multiple spines, A medical probe comprising a reference electrode disposed within the cavity, One or more processors, The system comprises a memory for storing instructions, and when an instruction is executed by one or more processors, it enables the medical system to: Receiving electrophysiological signals from at least some of the electrodes among the plurality of electrodes, Based on the electrophysiological signal and the position signal, the earliest excitation point identified as having the earliest excitation time is identified, Based on the electrophysiological signal and the position signal, identify a plurality of points closest to the earliest excitation point, having an excitation time less than a predetermined duration from the earliest excitation time. A medical system configured to generate an electroanatomical map of the heart based on data corresponding to the aforementioned multiple points, wherein the electroanatomical map represents the location of the earliest excitation points for subsequent ablation. (19) The medical system according to Embodiment 18, wherein when the instruction is executed by the one or more processors, the medical system is further configured to define a circumferential zone using a plurality of concentric circles having a radius of less than 10 millimeters from the earliest excitation point. (20) The medical system according to embodiment 19, wherein when the instruction is executed by the one or more processors, it is further configured to divide each concentric circle into three parts.

Claims

1. It is a medical system, A medical probe, A shaft extending along the longitudinal axis, A plurality of spines disposed at the distal end of the shaft, which are configured to bend radially outward from the longitudinal axis and define a cavity between the plurality of spines, A position sensor disposed on the longitudinal axis, configured to provide a position signal representing the position of the sensor and the medical probe within the heart, Multiple electrodes arranged along the multiple spines, A medical probe comprising a reference electrode disposed within the cavity, One or more processors, The system comprises a memory for storing instructions, and when an instruction is executed by one or more processors, it enables the medical system to... Receiving electrophysiological signals from at least some of the electrodes among the plurality of electrodes, Based on the electrophysiological signal and the position signal, the earliest excitation point identified as having the earliest excitation time is identified, Based on the electrophysiological signal and the position signal, identify a plurality of points closest to the earliest excitation point, having an excitation time less than a predetermined duration from the earliest excitation time. A medical system configured to generate an electroanatomical map of the heart based on data corresponding to the aforementioned multiple points, wherein the electroanatomical map represents the location of the earliest excitation points for subsequent ablation.

2. The medical system according to claim 1, wherein when the instruction is executed by one or more processors, the medical system is further configured to define a circumferential zone using a plurality of concentric circles having a radius of less than 10 millimeters from the earliest excitation point.

3. The medical system according to claim 2, wherein the instruction is further configured to divide each concentric circle into three parts when executed by the one or more processors.

4. It is a method, Navigating a medical probe to a target location within a patient's heart, wherein the medical probe comprises a plurality of spines extending along a longitudinal axis and configured to bend radially outward from the longitudinal axis, the plurality of spines comprising a plurality of electrodes disposed on the plurality of spines and at least one position sensor disposed on the longitudinal axis, the position sensor configured to provide a position signal representing the position of the sensor and the medical probe within the heart, Receiving electrophysiological signals from at least some of the electrodes among the plurality of electrodes, Based on the electrophysiological signal and the position signal, the earliest excitation point identified as having the earliest excitation time is identified, Based on the electrophysiological signal and the position signal, identify a plurality of points closest to the earliest excitation point, having an excitation time less than a predetermined duration from the earliest excitation time. A method comprising generating an electroanatomical map of the heart based on data corresponding to the aforementioned plurality of points, wherein the electroanatomical map represents the location of the earliest excitation points for subsequent ablation.

5. The method according to claim 4, further comprising defining a circumferential zone using a plurality of concentric circles having a radius of less than 10 millimeters from the earliest excitation point.

6. The method according to claim 5, further comprising dividing each concentric circle into three parts.

7. The method of claim 5, further comprising identifying additional points within the concentric circle having an excitation time less than the predetermined duration from the earliest excitation time, if one of the plurality of concentric circles includes a point having an excitation time less than the predetermined duration from the earliest excitation time.

8. The method of claim 5, further comprising using a previous point used to define each of the concentric circles if each of the plurality of concentric circles includes a point having an excitation time from the earliest excitation time to a predetermined duration.

9. The method of claim 5, further comprising defining a region based on the plurality of points and any point between the plurality of points including an excitation time from the earliest excitation time to an excitation time less than the predetermined duration.

10. The method according to claim 9, wherein the plurality of points include at least three points.

11. The method according to claim 4, wherein the plurality of spines include 10 spines, and each of the plurality of spines includes 10 electrodes.

12. The method according to claim 4, wherein the electrodes are arranged along a flexible printed circuit on each of the spines among the plurality of spines.

13. The method according to claim 4, wherein each of the plurality of electrodes is coated with an impedance-reducing coating.

14. The method according to claim 4, further comprising an actuator configured to deflect the spine radially outward to define a basket having a diameter adjustable from about 3 mm to 18 mm.

15. The method according to claim 4, wherein generating the electroanatomical map includes generating a map having a resolution of at least 924 points / minute.

16. The method according to claim 4, wherein the medical probe further comprises a reference electrode disposed in a cavity defined by the plurality of spines.

17. The method according to claim 16, wherein the reference electrode is configured to receive electrophysiological data used to reduce far-field signal components.

18. The method according to claim 4, wherein the at least one position sensor comprises a first magnetic sensor disposed at the distal end of the plurality of spines and a second magnetic sensor disposed at the proximal end of the plurality of spines.

19. The method according to claim 4, wherein the medical probe further comprises one or more position-sensing electrodes disposed on the shaft of the medical probe, and the one or more position-sensing electrodes are configured for impedance-based position detection.

20. The method according to claim 4, wherein the predetermined duration includes 10 milliseconds or less.

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