Basket catheter and electrode assembly configured for improved tissue contact

Abstract

The disclosed techniques include an end effector comprising a plurality of ridges extending along a longitudinal axis to define a basket assembly, the plurality of ridges are configured to bend radially outward from the longitudinal axis to define a radius of curvature relative to the longitudinal axis and to transition between an expanded configuration and a collapsed configuration. Each ridge of the plurality of ridges may include a section extending radially outward from a radius of curvature defined by a remainder of each ridge. The end effector may also include at least one electrode disposed on a section of each of the plurality of ridges.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 615,210, filed on December 27, 2023 (Attorney Docket No.: 253757.000194 (BIO6733USPSP1)), under 35 U.S.C. § 119, the entire content of which is hereby incorporated by reference as if set forth in full herein. Field of the Invention

[0003] The present invention generally relates to basket catheter assemblies and, more particularly, to basket catheter assemblies including spring-loaded electrodes disposed on ridges, the electrodes being configured to improve tissue contact. Background of the Invention

[0004] Intravascular catheters are commonly used to map and ablate myocardial tissue. Intravascular catheters typically include an end effector having one or more electrodes configured to receive electrical signals from tissue for mapping and / or to deliver ablation energy to tissue for ablation. To ensure that the electrodes are properly positioned for mapping or ablation, some end effectors include position sensing, such as electromagnetic position sensing or active current localization (ACL) techniques. Such position sensing techniques can also be used to detect the quality of contact between the ablation electrode and the target tissue.

[0005] In some existing catheters, the catheter includes ridges configured to bend radially outward to contact tissue with the electrodes. The ridges typically have a uniform radius of curvature along the entire ridge or a majority of the ridge. Because the radius of curvature of the ridges is uniform, when the basket catheter contacts the target tissue, additional portions of the ridges on either side of the electrodes also contact the target tissue. When determining the position of such electrodes, the user may not have access to sufficiently detailed information about the force applied to the electrodes that are separated from the ridges. As will be appreciated, it is desirable to obtain accurate data about the force applied to the electrodes as well as the position of each electrode. Accordingly, there is a need in the art for methods that improve the detectability of tissue contact of the electrodes while also obtaining accurate force data. The techniques disclosed herein address these and other problems. Summary of the Invention

[0006] According to an example of the present disclosure, an end effector for a medical device is provided, the end effector including a plurality of ridges that extend along a longitudinal axis to define a basket assembly. The plurality of ridges can be configured to bend radially outward from the longitudinal axis to define a radius of curvature relative to the longitudinal axis and transition between an expanded configuration and a collapsed configuration. Each of the plurality of ridges can include a section that extends radially outward from a radius of curvature defined by the remainder of each ridge. The end effector can further include at least one electrode disposed on the section of each of the plurality of ridges.

[0007] The disclosed technology can include an electrode assembly that includes an electrode body extending along a longitudinal axis and defining a recess and an electrode cap disposed at least partially within the recess. The electrode assembly can further include a spring member disposed within the recess, between the electrode body and the electrode cap, the spring member configured to cause the electrode cap to extend outward from the electrode body.

[0008] Additional features, functions, and applications of the disclosed technology are discussed in more detail herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic illustration of a medical system according to an example of the disclosed technology;

[0010] Figure 2A is a perspective view of a basket catheter in an expanded configuration according to an example of the disclosed technology;

[0011] Figure 2B is of a basket catheter in a collapsed configuration within a sheath according to an example of the disclosed technology Figure 2A side view;

[0012] Figure 3 is a front view of a basket catheter including a position sensor and in an expanded configuration according to an example of the disclosed technology;

[0013] Figure 4A is a front view of a basket catheter in an expanded configuration according to an example of the disclosed technology;

[0014] Figure 4B is of a basket catheter according to an example of the disclosed technology Figure 4A top view;

[0015] Figure 5A is a top perspective view of an electrode according to an example of the disclosed technology;

[0016] Figure 5B is of an electrode in Figure 5A side view;

[0017] Figure 6A is a front perspective view of a basket catheter in an expanded configuration including position sensors disposed along a ridge, according to an example of the disclosed technology;

[0018] Figure 6B is for a basket catheter to be disposed in Figure 6A a top perspective view of three position sensors on a ridge of the basket catheter;

[0019] Figure 7 is a perspective view of a basket catheter including a plurality of electrode assemblies disposed along a ridge, according to an example of the disclosed technology;

[0020] Figure 8A is a perspective view of an electrode assembly including an electrode cap, according to an example of the disclosed technology;

[0021] Figure 8B is, according to an example of the disclosed technology, Figure 8A a top view of the electrode assembly;

[0022] Figure 8C is, according to an example of the disclosed technology, Figure 8A a front side view of the electrode assembly;

[0023] Figure 8D is, according to an example of the disclosed technology, Figure 8A a side view of the electrode assembly;

[0024] Figure 9 is a cross-sectional view of an electrode assembly taken along line A-A shown in Figure 8B according to an example of the disclosed technology;

[0025] Figure 10 is, according to an example of the disclosed technology, Figures 8A to 9 an exploded view of the electrode assembly shown in;

[0026] Figure 11A is a perspective view of a spring member including strain gauges, according to an example of the disclosed technology;

[0027] Figure 11B is for three strain gauges to be disposed on Figure 11A the spring member, and

[0028] Figure 11C is a bottom perspective view of an electrode body including an electromagnetic coil, according to an example of the disclosed technology. DETAILED DESCRIPTION

[0029] The disclosed technology includes a basket catheter that can be configured for ablation and / or mapping. As will become apparent in the present disclosure, the ridge and electrode configurations of the basket catheter can be configured to help improve tissue contact of the electrodes. The disclosed technology also includes improved methods for detecting the force applied to each electrode and the position of each electrode. In some examples, the ridge can include a biasing section that causes the electrodes disposed along the biasing section to contact the tissue before the remainder of the ridge contacts the tissue. This helps ensure that the desired portion of the ridge contacts the target tissue first and improves overall electrode surface contact. In other examples, the ridge can include a position sensor and / or a strain gauge disposed along the ridge to obtain position and force data associated with the electrodes.

[0030] The disclosed technology also includes electrode assemblies configured to detect the contact force and position of each individual electrode. For example, the electrode assemblies can each include sensors to determine the force applied to the electrode assembly and the position and orientation of the electrode. That is, the sensors described herein allow determination of the position of the electrode and the direction of the force applied to the electrode. This is achieved by determining the position of the magnetic coils (which gives the position of the electrode), and knowing the displacement of one magnetic coil in the magnetic coils relative to another magnetic coil coupled to a spring (with a known spring constant) between the two magnetic coils allows determination of the force and its vector.

[0031] The following detailed description should be read in conjunction with the accompanying drawings, in which like reference numerals designate like elements in the different drawings. The drawings (not necessarily drawn to scale) depict selected examples and are not intended to limit the scope of the invention. The detailed description illustrates the principles of the invention by way of example and not by way of limitation. This description will clearly enable one of ordinary skill in the art to make and use the invention and describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.

[0032] As used herein, the term “about” or “approximately” with respect to any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or components to achieve its intended purpose as described herein. More specifically, “about” or “approximately” can refer to a range of values of ±20% of the recited value, e.g., “about 90%” can refer to a range of values from 71% to 110%. In addition, as used herein, the terms “patient,” “recipient,” “user,” and “subject” refer to any human or animal subject, and are not intended to limit the system or method to human use, but the use of the subject invention in a human patient represents a preferred embodiment. Similarly, the term “proximal” refers to a position closer to the operator or physician, and “distal” refers to a position farther from the operator or physician.

[0033] As discussed herein, the vasculature of a "patient", "recipient", "user", and "subject" can be that of a human or any animal. It should be understood that the animal can be of any suitable type, including but not limited to mammals, veterinary animals, livestock animals, or pet animals, etc. For example, the animal can be an experimental animal (e.g., rats, dogs, pigs, monkeys, etc.) specifically selected to have certain characteristics similar to humans. It should be understood that the subject can be, for example, any suitable human patient.

[0034] As discussed herein, a "physician" can include a doctor, surgeon, technician, scientist, operator, or any other individual or delivery instrumentation device associated with delivering a multi-electrode catheter for treating drug-refractory atrial fibrillation to a subject.

[0035] As discussed herein, when referring to the devices and corresponding systems of the present disclosure, the term "ablation" refers to components and structural features configured to reduce or prevent the generation of unstable cardiac signals in cells by utilizing non-thermal energy (such as reversible or irreversible electroporation (IRE), interchangeably referred to as pulsed electric field (PEF) and pulsed field ablation (PFA) in the present disclosure) or thermal energy (such as radiofrequency (RF) ablation or cryoablation). "Ablation" as used throughout the present disclosure, when referring to the devices and corresponding systems of the present disclosure, refers to thermal or non-thermal ablation of cardiac tissue for certain conditions, including but not limited to arrhythmia, atrial flutter ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The term "ablation" also includes known methods, devices, and systems for achieving various forms of ablation of body tissue understood by those skilled in the relevant art.

[0036] As discussed herein, the terms "tubular" and "tube" should be understood broadly and are not limited to structures that are a perfect cylinder or have a completely circular cross-section or a uniform cross-section along their entire length. For example, a tubular structure is typically illustrated as a structure that is substantially a perfect cylinder. However, without departing from the scope of the present disclosure, a tubular structure can have a tapered or curved outer or inner surface.

[0037] Reference Figure 1, which shows an exemplary catheter-based electrophysiological mapping and ablation system 10. System 10 includes a plurality of catheters that are inserted by a physician 24 through the vasculature of a patient 23 via the skin into the chambers or vascular structures of the heart 12. Generally, a delivery sheath catheter is inserted into the left atrium or right atrium near a desired location in the heart 12. Then, a plurality of catheters can be inserted into the delivery sheath catheter to reach that desired location. The plurality of catheters can include catheters dedicated to sensing intracardiac electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. For sensing IEGM, the physician 24 places the distal tip 28 of the catheter 14 in contact with the heart wall for sensing a target site in the heart 12. The end effector of the mapping catheter can include a basket catheter, a planar catheter, a focused catheter, a balloon catheter, etc. For ablation, the physician 24 similarly brings the distal end of the ablation catheter to the target site for ablation (as Figure 1 shown in the illustration). Similarly, the end effector of the ablation catheter can include a basket catheter, a planar catheter, a focused catheter, a balloon catheter, etc.

[0038] Catheter 14 is an exemplary catheter that includes one (and preferably a plurality of) electrode assemblies 26 that are optionally distributed on a plurality of ridges 22 at the distal tip 28 and are configured to deliver ablation energy to tissue. Catheter 14 can additionally include a position sensor 29 embedded in or near the distal tip 28 for tracking the position and orientation of the distal tip 28. Optionally and preferably, the position sensor 29 is a magnetic-based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0039] The magnetic-based position sensor 29 can operate in conjunction with a positioning pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predefined workspace. The real-time position of the distal tip 28 of the catheter 14 can be tracked based on the magnetic field generated by the positioning pad 25 and sensed by the magnetic-based position sensor 29. Details of magnetic-based position sensing techniques are described in U.S. Patent Nos. 5,391,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, 6,892,091, the entire contents of each of which are incorporated herein by reference. Sensors that provide contact force and position information via magnetic positioning techniques are shown and described in detail in U.S. Patent Nos. 8,437,832, 8,535,308, 8,784,413, and 8,357,152, the entire contents of each of which are incorporated herein by reference and included in the appendix submitted herewith.

[0040] System 10 includes one or more electrode patches 38 that are positioned to contact the skin of patient 23 to establish a position reference for impedance-based tracking of positioning pad 25 and electrode assembly 26. For impedance-based tracking, current is directed toward electrode assembly 26 and sensed at electrode skin patches 38 such that the position of each electrode can be triangulated via electrode patches 38. Details of impedance-based position tracking techniques are described in U.S. Patent Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, the entire contents of each of which are incorporated herein by reference.

[0041] Recorder 11 displays an electrogram 21 captured using body surface ECG electrodes 18 and an intracardiac electrogram (IEGM) captured using electrode assembly 26 of catheter 14. Recorder 11 may include pacing capabilities for pacing the heart rhythm and / or may be electrically connected to an independent pacemaker.

[0042] System 10 may include an ablation energy generator 50 that is adapted to conduct ablation energy to one or more electrodes at the distal end of a catheter configured for ablation. The energy generated by ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy or pulsed field ablation (PFA) energy (including unipolar or bipolar high voltage DC pulses that can be used to effect irreversible electroporation (IRE)), or a combination thereof.

[0043] Patient interface unit (PIU) 30 is an interface configured to establish electrical connectivity between a catheter, electrophysiology equipment, a power source, and a workstation 55 for controlling the operation of System 10. The electrophysiology equipment of System 10 may include, for example, multiple catheters, positioning pad 25, body surface ECG electrodes 18, electrode patches 38, ablation energy generator 50, and recorder 11. Optionally and preferably, PIU 30 further includes processing capabilities for performing real-time calculations of the position of the catheter and for performing ECG calculations.

[0044] Workstation 55 includes a memory, a processor unit with a memory or storage device loaded with appropriate operating software, and user interface capabilities. Workstation 55 can provide multiple functions, optionally including: (1) performing three-dimensional (3D) modeling of endocardial anatomy and rendering a model or anatomical map 20 for display on a display device 27; (2) displaying an activation sequence (or other data) compiled from the recorded electrograms 21 on the display device 27 as representative visual markers or images superimposed on the rendered anatomical map 20; (3) displaying the real-time position and orientation of multiple catheters within a heart chamber; and (4) displaying a site of interest on the display device 27, such as where ablation energy has been applied. A commercial product embodying the elements of system 10 can be the CARTO TM 3System, which is available from Biosense Webster, Inc., 31 Technology Drive, Suite 200, Irvine, CA 92618, USA.

[0045] Figure 2A FIG. is a schematic illustration showing a perspective view of catheter 14, which has an end effector 28 that is a basket assembly that is in an expanded form when unconstrained, such as by being pushed out of the tubular shaft lumen 80 at the distal end 85 of the tubular shaft 82 (as Figure 2B depicted therein). Figure 2B FIG. shows the basket assembly in a collapsed form within the tubular shaft 82. In the expanded form ( Figure 2A ), the ridges 22 bend radially outward along the longitudinal axis 86, and in the collapsed form ( Figure 2B ), the ridges are generally constrained by the inner wall of the tubular shaft 82 along the longitudinal axis 86 of the tubular shaft 82.

[0046] As Figure 2A shown, the basket assembly 28 (which may be interchangeably referred to herein as the "distal tip") includes a plurality of flexible ridges 22 that are formed at the end of a flexible shaft 84 and are connected at both ends. During a medical procedure, the physician 24 can deploy the basket assembly 28 by extending the flexible shaft 84 from the tubular shaft 82 to move the basket assembly 28 out of the tubular shaft 82 and into the expanded form. The ridges 22 can have an elliptical (e.g., circular) or rectangular (which may appear flat) cross-section and comprise a flexible elastic material forming struts (e.g., a shape memory alloy such as nitinol, also known as nickel-titanium), as will be described in more detail herein.

[0047] In the examples described herein, the electrode assembly 26 can be configured to deliver ablation energy (RF and / or IRE) to tissue in the heart 12 or other parts of the body of the patient 23. In addition to delivering ablation energy using the electrode assembly 26, the electrode assembly can also be used to measure physiological properties such as local surface potential (e.g., IEGM signal) at corresponding locations on tissue in the heart 12. The electrode assembly 26 can be biased such that a greater surface area of the electrode body of the electrode assembly 26 faces outward from the basket assembly 28, such that the electrode assembly 26 delivers a greater amount of electrical energy outward away from the basket assembly 28 (i.e., toward the heart 12 tissue) rather than inward toward the longitudinal axis 86 of the basket assembly 28. The basket assembly 28 can include a shaft 96 that extends longitudinally from the distal end 90 of the flexible shaft 84 toward the distal end 212 of the basket assembly 28. The basket assembly 28 can include a central intersection 211 that is at the point where the ridges 22 converge near the distal end 212.

[0048] Turning now to Figure 3 , which shows an exemplary end effector 28 in an expanded configuration. The end effector 28 can be configured to transition between an expanded configuration and a collapsed configuration. For example, the ridges 22 can include nitinol, and the nitinol can be heat-set to a predetermined shape (e.g., a deployed configuration) such that when the ridges 22 are inserted into the blood pool at a predetermined temperature, the ridges 22 will transition to the heat-set deployed configuration. In some examples, each of the plurality of ridges 22 can be covered in a biocompatible insulating material layer. The end effector 28 can include a plurality of ridges 22, each of the plurality of ridges 22 extending along the longitudinal axis 86 and configured to bend radially outward from the longitudinal axis 86 to define a radius of curvature 328 relative to the longitudinal axis 86 and form a basket shape.

[0049] As Figure 3 shown, each of the plurality of ridges 22 can also include a plurality of electrodes 26 disposed on each ridge 22. The electrodes 26 can be disposed on the respective ridges 22 such that the electrodes 26 of adjacent ridges 22 are not horizontally aligned, but rather are staggered from each other. For example, the electrode 26A of ridge 22A is not horizontally aligned with the electrode 26B of ridge 22B. The end effector 28 can also include a central position sensor 342 attached to a central delivery shaft 340, the central delivery shaft 340 being positioned within the center of the end effector 28 and emerging from where the ridges 22 of the plurality of ridges 22 converge proximally. In other examples, the central position sensor 342 can be disposed on the shaft 96.

[0050] As shown, each of the plurality of ridges 22 may include a bias section 320 that extends radially outward from a radius of curvature 328 defined by the remainder of each ridge 22. The bias section 320 may cause the electrode 26 to contact the tissue before the remainder of each ridge 22 in the plurality of ridges 22 contacts the target tissue. In other words, the bias section 320 may be configured to position the electrode 26 further away from the longitudinal axis 86 such that the electrode 26 may contact the tissue before other portions of the end effector 28. As will be appreciated, this may help ensure sufficient contact of the electrode 26 with the tissue.

[0051] In some examples, as will be shown in further detail in Figures 6A to 6B the ridges 22 may also include position sensors 650 disposed at each bias section 320 of each ridge 22. For example, the position sensors 650 may be disposed below or on either side of the respective electrode 26, as Figure 6A shown. As described above, the end effector 28 may include a central position sensor 342 disposed centrally within the end effector 28. This may be used in combination with the position sensors 650 disposed at the bias sections 320 to determine the amount of deflection experienced by the ridges 22. This information may be used to determine the magnitude and direction of the force applied to the end effector 28. For example, if the spring constant of the bias section 320 is known, this information may be used in conjunction with the detected positions of the electrodes 26A, 26B on the bias section 320 relative to each other and relative to the central position sensor 342 to determine the magnitude and direction of the force experienced by the electrode 26. Thus, a detailed picture of both the magnitude and direction of the force applied to the end effector 28 may be calculated.

[0052] For illustration, if the basket assembly 28 is caused to contact the tissue on a first side, the electrodes 26 on that first side will be pushed inwardly towards the central position sensor 342 and the electrodes 26 on the second, opposite side will be pushed outwardly away from the central position sensor 342. In addition to the spring constant of the ridges 22, by knowing the positions of the electrodes 26 relative to the central position sensor 342, the magnitude and direction of the force applied to the basket assembly 28 may be determined. Similarly, coils disposed on the electrodes may be used to determine the position of the electrodes in free space, such as triangulated via an external magnetic field generator.

[0053] Now refer to Figures 4A to 4B, which shows an alternative end effector 28 that includes a plurality of ridges 22 that define a basket shape in an expanded configuration but does not include a central position sensor 342. As described above, each of the plurality of ridges 22 may extend along a longitudinal axis 86 and may be configured to bend radially outward and away from the longitudinal axis 86 when the end effector 28 is in the expanded configuration. Each of the plurality of ridges 22 may be configured to converge at a central intersection 211 that defines the distal end of the end effector 28. Additionally, the plurality of ridges 22 may include a plurality of electrodes 26 that are disposed along the ridges 22 at a biased section 320 of the ridges 22.

[0054] Now turning to Figures 5A to 5B , which shows an electrode 26 that is configured to be disposed along a ridge 22 of a basket catheter. The electrode 26 may include an electrode body 532 that defines a lumen 534 that may be configured to receive the ridge 22. In other words, the electrode 26 may be configured to slide onto the ridge 22. The electrode 26 may also include an electrode surface 530 that is configured to contact target tissue in an organ 12 of a patient 23. In some examples, the electrode body 532 may include an insulating material while the electrode surface 530 is non-insulating to ensure that ablation energy is delivered only through the electrode surface 530 and to protect the electrode body 532 from ablation energy. In other examples, the entire electrode 26 may be conductive.

[0055] Figure 6A shows an alternative end effector 28 in an expanded configuration. The end effector 28 may include a plurality of ridges 22 that extend along a longitudinal axis 86 and define a basket shape when the end effector 28 is in the expanded configuration. In some examples, at least some of the plurality of ridges 22 may include a position sensor 650 disposed along the ridge 22. Similar to Figure 3 the end effector 28 shown, each of the plurality of ridges 22 may be configured to bend radially outward from the longitudinal axis 86 to define a radius of curvature 328 of each ridge 22. Each ridge may also include a biased section 320 that extends radially outward from the radius of curvature 328 defined by the remainder of each ridge 22.

[0056] As described above, the plurality of position sensors 650 may be disposed along the ridges 22. For example, the position sensor 650 may be disposed on the ridge 22 at each biased section 22A, 22B of each ridge 22 such that the position sensor 650 is positioned below or beside the electrode 26. In some examples, the end effector 28 may include a plurality of position sensors 650A to 650C disposed at each biased section 22A, 22B of each ridge 22. As Figure 6BAs shown, a plurality of position sensors 650A to 650C may include at least three position sensors 650A to 650C, which are positioned approximately 60 degrees from each other to form a triaxial sensor. As will be appreciated, the position data collected by the triaxial sensor can be used to more accurately determine the position and orientation of each biasing section 320 of each ridge 22.

[0057] As yet another example, the end effector 28 may alternatively include one or more strain gauges disposed on the biasing section 320 of the ridge 22, as will be described with respect to Figure 11B that shown and described. The strain gauges can similarly be used to determine the magnitude of the force experienced by the biasing section 320 of the ridge 22 by detecting the strain applied to the ridge 22. In turn, this force data can be used to determine the magnitude of the force applied to each electrode 26.

[0058] Now referring to Figure 7 , which shows an alternative end effector 728 in a deployed configuration. The end effector 728 may include a plurality of ridges 722 that extend along a longitudinal axis 86 and define a basket shape when the end effector 728 is in the deployed configuration. The ridges 722 may be configured to bend radially outward from the longitudinal axis 86 of the end effector 728. Additionally, the ridges 722 may be configured to converge at a central intersection 711 and define a distal end 712 of the end effector 728. Each ridge 722 may include one or more electrode assemblies 726 disposed along the ridge 722. As previously described, each electrode assembly 726 among the electrode assemblies 726 may be positioned at a biasing section 722 of each ridge 722 along the ridge 726. Alternatively, the ridge 22 may not include a biasing section, but the electrode assembly 726 may be configured such that the outward-facing portion (the portion of the electrode assembly 726 that faces away from the longitudinal axis 86) may be larger than the inward-facing portion (the portion of the electrode assembly 726 that faces the longitudinal axis 86). Each electrode assembly 726 among the electrode assemblies 726 may further include an electromagnetic coil 770 disposed on the inward-facing side of the electrode body 740, as will be further explained in detail in Figure 11C .

[0059] Now turning to Figures 8A to 8D , which shows an electrode assembly 726 disposed along the ridge 722 as shown in Figure 7 . The electrode assembly 726 may include an electrode body 740, an electrode cap 742, and a lumen 744 that extends through the electrode body 740 and is configured to receive the ridge 722. The electrode cap 742 may be centrally positioned on the topmost surface of the electrode body 740, as shown in Figure 8B . The electrode body 740 may define a notch 746 at respective ends of the lumen 744, as shown in Figure 8CAs shown. This allows the electrode assembly 726 to fully receive the ridge 722 and allows the ridge 722 to bend. In some examples, in addition to being disposed on a basket catheter as shown in Figure 7 shown, Figures 8A to 8D the electrodes shown can be similarly disposed on the end effector 28 including the biasing section 320, similar to those shown in Figures 3 to 4B shown. Figures 9 to 11C Details of these electrode assemblies 726 are further shown.

[0060] Figures 9 to 10 Shown is Figures 8A to 8D an exemplary electrode assembly 726 similar to the electrode assembly 726 shown. As shown in Figure 9 visible, Figure 9 is a cross-sectional view of the electrode assembly 726 taken along line A-A shown in Figure 8B shown. The electrode assembly 726 can include an electrode body 740 and an electrode cap 742 disposed within a recess 748 defined by the electrode body 740. As previously described, the electrode body 740 can include a lumen 744 that extends through the electrode body 740 and is configured to receive the ridge 722 of the end effector 728. The recess 748 of the electrode body 740 can include a spring member 750 that is disposed in the recess 748 between the electrode body 740 and the electrode cap 742. The electrode assembly 726 can also include a sensor assembly 761. The sensor assembly 761 has a movable coil 760, an elastic member 750 coupled to the first coil 760, and a fixed coil 762. The fixed coil 762 can be connected to the Biosense Webster Carto3 system to emit a magnetic field at a predetermined frequency, and the movable coil 760 can be configured to receive the emitted magnetic field, and the emitted magnetic field induces a current in the movable coil 760. Carto3 can use the induced current in the movable coil 760 to determine the position of the movable coil or sensor 760 relative to the fixed coil or sensor 762. At least one position sensor or coil 760 can be disposed within the electrode cap 742, and at least one position sensor or coil 762 can be disposed within the electrode body 740 between the lumen 744 and the recess 748.

[0061] In some examples, the spring member 750 can be configured to apply a force to the electrode cap 742 that can cause the electrode cap 740 to extend outwardly and away from the electrode body 740. As shown in Figure 10As shown, the recess 748 of the electrode body 740 may include a lip 749 extending around the recess 748, and the electrode cap 740 may include an edge 743 extending around the circumference of the electrode cap 742. The lip 749 of the recess 748 may be configured to help hold the electrode cap 740 on the electrode body 740. For example, the edge 743 of the electrode cap 740 may be configured to slide along the lip 749 but not be removed from the lip 749 to prevent removal of the electrode cap 740. For example, when the electrode assembly 726 is in contact with tissue, the spring member 750 and the position sensors 760, 762 may be used together to calculate the magnitude of the force applied to the electrode assembly 726. For example, if the spring constant of the spring member 750 is known, the disclosed techniques may determine the force applied to the electrode cap 742 by determining the displacement of the position sensor 760 in the electrode cap 742 relative to the position sensor 762 in the electrode body 740 and correlating the displacement with the spring constant of the spring member 750. In this way, the magnitude of the force applied to each electrode assembly 726 may be determined and output for a physician to view.

[0062] Now referring to Figure 11A , which shows a spring member 750 that may be disposed within the Figures 7 to 10 electrode assembly 726 shown. In some examples, the spring member 750 may alternatively or additionally include a strain gauge 752 disposed on the spring member 750. The strain gauge 752 may be configured to determine the magnitude of the force applied by the spring member 750 to the electrode cap 742. In some examples, the spring member 750 may further include three strain gauges 752A to 752C that are disposed on the spring member 750 and are separated from each other by approximately 60 degrees, as Figure 11B shown, for determining the magnitude and direction of the force applied to the electrode cap 742. In some examples, the strain gauges 752A to 752C may include a flexible circuit that is configured to detect strain when bent.

[0063] Figure 11C shows a bottom view of the electrode body 740. In this example, the electrode body 740 may include one or more electromagnetic coils 770 disposed on the underside of the electrode body 740. In some examples, the electromagnetic coils 770 of the electrode body 740 may include a first electromagnetic coil and a second electromagnetic coil 770, and the first electromagnetic coil and the second electromagnetic coil may include a biaxial sensor. In other examples, the electrode body 740 may include only one electromagnetic coil or more than two electromagnetic coils, or any number suitable for a particular application. Each electromagnetic coil 770 may be configured to output a current and detect the position of the electrode assembly 726 when subjected to an electromagnetic field. As will be appreciated, by including one or more electromagnetic coils 770 on the electrode assembly 726, the disclosed techniques may be configured to determine the position and orientation of each electrode assembly 726 on the basket catheter 728.

[0064] The disclosed technology described herein can be further understood in accordance with the following terms:

[0065] Clause 1: An end effector for a medical device, the end effector comprising: a plurality of ridges extending along a longitudinal axis to define a basket assembly, the plurality of ridges configured to bend radially outward from the longitudinal axis to define a radius of curvature relative to the longitudinal axis and transition between an expanded configuration and a collapsed configuration, each of the plurality of ridges including a section extending radially outward from the radius of curvature defined by the remainder of each ridge; and at least one electrode disposed on a spring-biased section of each of the plurality of ridges.

[0066] Clause 2: The end effector according to Clause 1, wherein a plurality of electrodes are disposed on each of the plurality of ridges.

[0067] Clause 3: The end effector according to Clause 1, wherein each of the plurality of electrodes is disposed on a corresponding section of each of the plurality of ridges.

[0068] Clause 4: The end effector according to Clause 3, wherein the section of each of the plurality of ridges is configured such that when the end effector contacts tissue, each corresponding electrode of the plurality of electrodes contacts the tissue before the remainder of each ridge contacts the tissue.

[0069] Clause 5: The end effector according to Clause 1, wherein the at least one electrode is configured to deliver ablation energy to tissue.

[0070] Clause 6: The end effector according to Clause 3, the end effector further comprising a position sensor disposed on each corresponding section and configured to detect the position of the section.

[0071] Clause 7: The end effector according to Clause 6, wherein each position sensor is disposed on the section below the corresponding electrode of the plurality of electrodes.

[0072] Clause 8: The end effector according to Clause 1, wherein each electrode comprises: an electrode body defining a recess and a lumen extending through the electrode body; an electrode cap at least partially disposed in the recess; and a spring member disposed in the recess between the electrode body and the electrode cap, the spring member configured to cause the electrode cap to extend outward from the electrode body.

[0073] Clause 9: The end effector according to Clause 8, wherein the end effector further comprises a sensor coupled to the spring member, the sensor being configured to detect a force applied to the electrode.

[0074] Clause 10: The end effector according to Clause 8, wherein the electrode body further defines a lip extending around the recess, the lip being configured to prevent the electrode cap from being removed from the recess.

[0075] Clause 11: The end effector according to Clause 8, wherein the lumen is configured to receive a ridge among the plurality of ridges.

[0076] Clause 12: The end effector according to Clause 8, wherein the end effector further comprises a position sensor disposed on the electrode body and configured to output a current when subjected to an electromagnetic field to detect the position of the electrode.

[0077] Clause 13: The end effector according to Clause 12, wherein the position sensor is disposed on an inward-facing side of the electrode body facing the longitudinal axis.

[0078] Clause 14: The end effector according to Clause 12, wherein the position sensor is a first position sensor, and the end effector further comprises a second position sensor disposed on the electrode body and configured to output a current when subjected to an electromagnetic field to detect the position of the electrode.

[0079] Clause 15: The end effector according to Clause 14, wherein the first position sensor and the second position sensor comprise a biaxial sensor.

[0080] Clause 16: An electrode assembly, comprising: an electrode body extending along a longitudinal axis and defining a recess; an electrode cap at least partially disposed in the recess; and a spring member disposed in the recess between the electrode body and the electrode cap, the spring member being configured to cause the electrode cap to extend outwardly from the electrode body.

[0081] Clause 17: The electrode assembly according to Clause 16, wherein the electrode assembly further comprises a sensor coupled to the spring member, the sensor being configured to detect a force applied to the electrode.

[0082] Clause 18: The electrode assembly according to Clause 16, wherein the electrode body further defines a lip extending around the recess, the lip being configured to prevent the electrode cap from being removed from the recess.

[0083] Clause 19: For the electrode assembly according to Clause 16, the electrode body further defines a lumen configured to receive a ridge, and the ridge is configured to support the electrode assembly.

[0084] Clause 20: For the electrode assembly according to Clause 16, the electrode assembly further includes a position sensor disposed on the electrode body and configured to output a current to detect the position of the electrode when subjected to an electromagnetic field.

[0085] Clause 21: For the electrode assembly according to Clause 20, the position sensor is disposed on the inward-facing side of the electrode body.

[0086] Clause 22: For the electrode assembly according to Clause 20, the position sensor is a first position sensor, and the electrode assembly further includes a second position sensor disposed on the electrode body and configured to output a current to detect the position of the electrode when subjected to an electromagnetic field.

[0087] Clause 23: For the electrode assembly according to Clause 22, the first position sensor and the second position sensor include a biaxial sensor.

[0088] Clause 24: For the electrode assembly according to Clause 16, the electrode assembly further includes a first position sensor disposed on the electrode cap and a second position sensor disposed on the electrode body.

[0089] The above embodiments are cited by way of example, and the present invention is not limited to what is specifically shown and described above. On the contrary, the scope of the present invention includes combinations and sub-combinations of the various features described above, as well as their variations and modifications, which will occur to those skilled in the art upon reading the above description and which are not disclosed in the prior art.

Claims

1. An end effector for a medical device, the end effector comprising: a plurality of ridges extending along a longitudinal axis to define a basket assembly, the plurality of ridges being configured to bend radially outward from the longitudinal axis to define a radius of curvature relative to the longitudinal axis and to transition between an expanded configuration and a collapsed configuration, each ridge of the plurality of ridges including a segment extending radially outward from the radius of curvature defined by a remainder of each ridge; and At least one electrode is disposed on the segment of each ridge of the plurality of ridges.

2. The end effector of claim 1, a plurality of electrodes disposed on each of the plurality of ridges.

3. The end effector of claim 1, each electrode of the plurality of electrodes being disposed on a corresponding segment on each ridge of the plurality of ridges.

4. According to the end actuator of claim 3, the segment of each ridge of the plurality of ridges is configured so that when the end actuator contacts the tissue, each corresponding electrode of the plurality of electrodes contacts the tissue before the remaining portion of each ridge contacts the tissue.

5. The end effector of claim 1, the at least one electrode being configured to deliver ablation energy to tissue.

6. The end effector of claim 3, further comprising a position sensor disposed on each respective segment and configured to detect a position of the segment.

7. The end effector according to claim 6, each position sensor is disposed on the section below a corresponding electrode among the plurality of electrodes.

8. The end effector of claim 1, each electrode comprising: an electrode body defining a recess and a lumen extending through the electrode body; an electrode cap, the electrode cap being at least partially disposed in the recess; and A spring member is disposed in the recessed portion and between the electrode body and the electrode cap, the spring member being configured to cause the electrode cap to extend outward from the electrode body.

9. The end actuator according to claim 8 further includes a force sensor assembly, the force sensor assembly including a first coil coupled to the spring member and a second coil fixed to the electrode, the first coil sensor being configured to output a current in response to a magnetic field for determining a force applied to the electrode.

10. The end effector of claim 8, the electrode body further defining a lip extending around the recess, the lip configured to prevent removal of the electrode cap from the recess.

11. The end effector of claim 8, said lumen being configured to receive a ridge of said plurality of ridges.

12. The end effector according to claim 8, further comprising a position sensor disposed on the electrode body and configured to output a current to detect the position of the electrode when subjected to an electromagnetic field.

13. The end effector of claim 12, the position sensor being disposed on an inwardly facing side of the electrode body that faces the longitudinal axis.

14. The end actuator according to claim 12, wherein the position sensor is a first position sensor, and the end actuator further comprises a second position sensor, which is disposed on the electrode body and is configured to output a current to detect the position of the electrode when subjected to an electromagnetic field.

15. The end effector of claim 14, the first position sensor and the second position sensor comprising dual-axis sensors.

16. An electrode assembly, comprising: an electrode body extending along a longitudinal axis and defining a recess; an electrode cap, the electrode cap being at least partially disposed in the recess; and A spring member is disposed in the recessed portion and between the electrode body and the electrode cap, the spring member being configured to cause the electrode cap to extend outward from the electrode body.

17. The electrode assembly of claim 16, further comprising a force sensor assembly comprising a first coil coupled to the spring member and a second coil fixed to the electrode body, the force sensor assembly being configured to detect a force applied to the electrode. 18 . The electrode assembly of claim 16 , the electrode body further defining a lip extending around the recess, the lip configured to prevent the electrode cap from being removed from the recess.

19. The electrode assembly of claim 16, the electrode body further defining a lumen configured to receive a ridge configured to support the electrode assembly. 20 . The electrode assembly of claim 16 , further comprising a position sensor disposed on the electrode body and configured to output a current to detect a position of the electrode when subjected to an electromagnetic field.

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