Encapsulation catheter with framework

Abstract

To provide a framework for an end effector of a medical device.SOLUTION: The framework includes a base, a first cantilevered spine, a second cantilevered spine, and a first support. The base connects with an elongate shaft of the medical device. The first cantilevered spine extends from the base along the longitudinal axis to a terminal portion. The second cantilevered spine extends from the base portion to a terminal portion along the longitudinal axis. The first support connects a terminal portion of the first cantilevered spine with an intermediate portion of the second cantilevered spine.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority under 35 U.S.C. § 119 to earlier filed U.S. Provisional Patent Application No. 63 / 669,344, filed July 10, 2024 (Attorney Docket No. 253757.000498 (BIO6936USPSP1)), the entire contents of which are incorporated herein by reference as if fully set forth herein.

[0002] FIELD OF THE INVENTION TECHNICAL FIELD The present technology relates generally to medical devices, and more particularly, but not exclusively, to medical probes having electrodes, and further to medical probes suitable for use for tissue mapping and ablation. [Background technology]

[0003] Cardiac arrhythmias, such as atrial fibrillation, occur when electrical signals are abnormally conducted from an area of ​​cardiac tissue to adjacent tissue, disrupting the normal cardiac cycle and causing an asynchronous rhythm. The source of the unwanted signals may be located in the atrial or ventricular tissue. The unwanted signals may be conducted through the cardiac tissue to other locations and cause or perpetuate the arrhythmia.

[0004] Treatments for arrhythmias include surgically disrupting the source of the signals that cause the arrhythmia and interrupting the conduction pathways of such signals. More recently, it has been discovered that by mapping the electrical properties and volume of the endocardium and selectively ablating cardiac tissue through the application of energy, it is possible to interrupt or modify the propagation of unwanted electrical signals from one portion of the heart to another. The ablation process disrupts the unwanted electrical pathways through the creation of non-conductive lesions.

[0005] In this two-step procedure, which involves mapping followed by ablation, electrical activity at points within the heart is sensed and measured, typically by advancing a catheter equipped with one or more electrical sensors into the heart and acquiring data at multiple points, which are then used to select a target area where ablation will be performed.

[0006] For higher mapping resolution, it is desirable for a mapping catheter to closely conform to the target anatomical structure. For mapping within the atria or ventricles (e.g., the apex of the ventricles), it is desirable for the catheter to collect more data signals in a shorter period of time. It is also desirable for such a catheter to enable sufficient electrode contact with various tissue surfaces, e.g., flat, curved, irregular, or non-planar surface tissue, and be foldable for non-invasive advancement and retraction through the patient's vascular system. Existing catheters generally require rigid internal structural members to ensure that a predetermined configuration is maintained. Rigidity is a disadvantage during manipulation within a body organ because it can prevent electrodes from contacting tissue.

[0007] Other catheters may include flexible end effectors designed to overcome this disadvantage. These catheters may include layered components that can be time-consuming, complex, and expensive to manufacture and assemble. Additionally, the electrical traces and other associated components may be prone to breakage and / or delamination during use. Summary of the Invention [Means for solving the problem]

[0008] According to the disclosed technology, a framework for an end effector of a medical device is provided. The framework includes a base, a first cantilevered spine, a second cantilevered spine, and a first support. The base is configured to connect to an elongate shaft of a medical device and extends distally along a longitudinal axis. The first cantilevered spine extends from the base to a distal portion along the longitudinal axis. The second cantilevered spine extends from the base to a distal portion along the longitudinal axis. The first support connects the distal portion of the first cantilevered spine to an intermediate portion of the second cantilevered spine.

[0009] The presently disclosed technology also provides an end effector for a catheter. The end effector includes a framework, a flexible circuit, and an insulating material. The framework includes a base and a plurality of spines extending from the base along a longitudinal axis. The flexible circuit includes a plurality of segments extending along the longitudinal axis, the plurality of segments defining areas not covered by any material, and a plurality of electrodes disposed on each of the segments. The insulating material is disposed between the framework and the flexible circuit such that the framework is spaced from the flexible circuit.

[0010] The disclosed technique also provides an end effector for a catheter. The end effector includes a framework including a base and a plurality of spines extending from the base along a longitudinal axis. The end effector includes a position sensor spaced from the framework, the position sensor including a plurality of position sensing loops. The position sensing loops include a pair of side loops arranged generally symmetrically about the longitudinal axis. Each side loop extends in a loop from a proximal portion of the framework to a distal portion of the framework and returns along the longitudinal axis to the proximal portion of the framework.

[0011]

[0010] There is also provided, in accordance with an embodiment of the disclosed technology, a flexible circuit. The flexible circuit includes a substrate layer including a stretchable polymer material. The flexible circuit includes one or more conductive traces connected to the substrate layer and configured to conduct electrical current. The flexible circuit includes one or more strain reduction features connected to the substrate layer. Each strain reduction feature includes one of a sacrificial trace connected to the substrate layer, a heat sink connected to a base of the substrate layer, or a localized stiffener connected to the substrate layer in a region where a portion of the one or more conductive traces extend.

[0012] The presently disclosed technology also provides an end effector for a catheter. The end effector includes a framework, a flexible circuit, and an insulating material. The framework includes a plurality of spines extending along a longitudinal axis. The flexible circuit includes a substrate layer including a stretchable polymer material, a plurality of conductive traces connected to the substrate layer and configured to conduct electrical current, a plurality of electrodes connected to the substrate layer, each conductive trace of the plurality of conductive traces connected to a respective electrode of the plurality of electrodes, and one or more strain reduction features connected to the substrate layer. Each strain reduction feature includes one of: (i) a sacrificial trace connected to the substrate layer; (ii) a heat sink connected to a base of the substrate layer; or (iii) a localized stiffener connected to the substrate layer in a region where a portion of one or more conductive traces of the plurality of conductive traces extends. The insulating material at least partially encases the framework and the flexible circuit.

[0013] The presently disclosed technology also provides a method for manufacturing an end effector for a medical device. The method includes forming a framework that is substantially planar along a longitudinal axis. The method includes forming a flexible circuit, the method including forming a substrate layer including a stretchable polymer material and providing one or more conductive traces on the substrate layer. The method includes providing one or more strain reduction features on the substrate layer of the flexible circuit. The method includes disposing the flexible circuit above the framework. The method includes heating an insulating material. The method includes reflowing the insulating material so that the insulating material encases the framework and the flexible circuit.

[0014] The disclosed technology further provides a flexible circuit extending along a longitudinal axis. The flexible circuit includes a substrate layer and a plurality of conductive traces. The conductive traces are connected to the substrate layer and configured to conduct electrical current. Each conductive trace includes a serpentine shape including a plurality of arc sections, each arc section defining a pair of voids having opposing open ends. Each conductive trace generally extends along the longitudinal axis adjacent to one or more of the plurality of conductive traces such that each arc section of any respective conductive trace of the plurality of traces is laterally spaced from a void of an arc section of an adjacent one or more conductive traces. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic, pictorial illustration of a medical system including a medical device, including a medical probe having an end effector with electrodes, in accordance with the disclosed technology; [Figure 2] FIG. 1 is a schematic, pictorial diagram showing an exploded perspective view of a first exemplary end effector in accordance with the disclosed technology; [Figure 3A] FIG. 1 is a schematic pictorial diagram showing a top view of a framework of a first end effector in accordance with the disclosed technology; [Figure 3B]FIG. 10 is a schematic, pictorial diagram showing a top view of a position sensor of a first end effector in accordance with the disclosed technology; [Figure 3C] 3B is a schematic, pictorial diagram showing a plan view of an alternative position sensor similar to that of FIG. 3B disposed on the framework of FIG. 3A in accordance with the disclosed technology. [Figure 3D] 3B disposed on the framework of FIG. 3A, in accordance with the disclosed technology. FIG. [Figure 3E] FIG. 1 is a schematic pictorial diagram showing a top view of a first end effector in accordance with the disclosed technology; [Figure 4] 3E is a schematic pictorial diagram showing a plan view opposite that of FIG. 3E showing the position sensor of FIG. 3B disposed on the framework of FIG. 3A and the flexible circuit of FIG. 3E in accordance with the disclosed technology, with the position sensor of FIG. 3B shown in phantom lines. [Figure 5A] FIG. 10 is a schematic, pictorial diagram showing a top view of a framework and position sensors disposed on a flexible circuit of a second exemplary end effector in accordance with the disclosed technology. [Figure 5B] FIG. 10 is a schematic pictorial diagram showing a top view of a position sensor of a second end effector in accordance with the disclosed technology; [Figure 5C] FIG. 10 is a schematic, pictorial diagram showing a top view of a framework and position sensors disposed on a flexible circuit of a second exemplary modified end effector in accordance with the disclosed technology. [Figure 6A] FIG. 10 is a schematic, pictorial diagram showing a top view of a third exemplary end effector in accordance with the disclosed technology. [Figure 6B] FIG. 10 is a schematic, pictorial diagram showing a top view of a framework and position sensors disposed on a flexible circuit of a third exemplary end effector in accordance with the disclosed technology. [Figure 6C] FIG. 10 is a schematic, pictorial diagram showing a top view of a position sensor of a third end effector in accordance with the disclosed technology. [Figure 7A] FIG. 10 is a schematic, pictorial diagram showing a top view of a fourth exemplary end effector in accordance with the disclosed technology. [Figure 7B] FIG. 10 is a schematic pictorial diagram showing a position sensor of a fourth end effector in solid lines and other subcomponents in phantom lines in accordance with the disclosed technology. [Figure 7C] FIG. 10 is a schematic, pictorial diagram illustrating a position sensor of a fourth end effector in accordance with the disclosed technology; [Figure 8A] FIG. 1 is a schematic pictorial diagram showing a plan view of a flexible circuit in accordance with the disclosed technology. [Figure 8B] FIG. 8B is a schematic pictorial diagram showing a cross-sectional view of the flexible circuit of FIG. 8A in accordance with the disclosed technology. [Figure 9A] FIG. 1 is a schematic, pictorial diagram illustrating a first strain reduction mechanism for a flexible circuit in accordance with the disclosed technology. [Figure 9B] FIG. 9B is a schematic pictorial diagram showing a cross-sectional view of the flexible circuit of FIG. 9A incorporating a first strain reduction feature in accordance with the disclosed technology. [Figure 10A] FIG. 10 is a schematic, pictorial diagram illustrating a second strain reduction mechanism for a flexible circuit in accordance with the disclosed technology. [Figure 10B] FIG. 10B is a schematic pictorial diagram showing a cross-sectional view of the flexible circuit of FIG. 10A incorporating a second strain reduction feature in accordance with the disclosed technology. [Figure 11] FIG. 10 is a schematic, pictorial diagram illustrating a third strain reduction mechanism for a flexible circuit in accordance with the disclosed technology. [Figure 12] FIG. 1 is a schematic pictorial diagram showing a cross-sectional view of an end effector incorporating a strain reduction mechanism in accordance with the disclosed technology. [Figure 13] 1 is a flowchart of a method of manufacturing an end effector for a medical device in accordance with the techniques of the present disclosure. [Figure 14A] FIG. 10 is a schematic pictorial diagram showing a top view of another flexible circuit in accordance with the disclosed technology. [Figure 14B] FIG. 14B is a schematic pictorial diagram showing a detail view of Detail A of FIG. 14A, in accordance with the disclosed technology. [Figure 14C] FIG. 14B is a schematic pictorial diagram showing a detail view of Detail B of FIG. 14A, in accordance with the disclosed technology. [Figure 14D]FIG. 14B is a schematic pictorial diagram showing a detail view of Detail C of FIG. 14A, in accordance with the disclosed technology. DETAILED DESCRIPTION OF THE INVENTION

[0016] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates, by way of example, but not by way of limitation, the principles of the invention. This description will clearly enable any person skilled in the art to make and use the invention and sets forth several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is presently contemplated to be the best mode for carrying out the invention.

[0017] As used herein, the terms "about," "approximately," or "generally" in connection with any numerical value or range indicate a suitable dimensional tolerance that enables a portion or collection of components to function for the intended purpose described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value, while, for example, "about 90%" may refer to a range of values ​​of 71% to 110%. Additionally, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject, and while use of the subject technology in human patients represents a preferred embodiment, it is not intended to limit the systems or methods to human use. Similarly, the term "proximal" refers to a location closer to the operator or physician, while "distal" refers to a location farther from the operator or physician.

[0018] As discussed herein, the vascular system of a "patient," "host," "user," and "subject" may be that of a human or any animal. It should be understood that the animal may be of any of a variety of applicable types, including, but not limited to, mammals, veterinary animals, livestock animals, or companion animals. As an example, the animal may be a laboratory animal (e.g., rat, dog, pig, monkey, etc.) specifically selected to have certain characteristics similar to humans. It should be understood that the subject may be, for example, any applicable human patient.

[0019] As discussed herein, an "operator" may include a physician, surgeon, technician, scientist, or any other individual or delivery instrument associated with the delivery of a multi-electrode catheter for the treatment of drug-refractory atrial fibrillation to a subject.

[0020] The present disclosure relates to systems, methods, uses, and devices for mapping and ablation of cardiac tissue to treat cardiac arrhythmias. Ablation energy is typically delivered to cardiac tissue by a distal portion of a catheter capable of delivering the ablation energy along the tissue to be ablated. Some exemplary catheters include a three-dimensional structure at the distal portion and are configured to administer the ablation energy from various electrodes positioned on the three-dimensional structure. Ablation procedures incorporating such exemplary catheters can be visualized using fluoroscopy.

[0021] Ablation of cardiac tissue using radiofrequency (RF) energy and thermal techniques, such as cryoablation, to improve cardiac function is a well-known procedure. Successful ablation using thermal techniques typically requires measuring cardiac potentials at various locations in the myocardium. Additionally, temperature measurements during ablation provide data that enables assessment of ablation effectiveness. Typically, ablation procedures using thermal techniques involve measuring electrode potentials and temperatures before, during, and after the actual ablation. RF approaches can pose risks that can lead to tissue charring, burning, steam popping, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulas. Cryoablation is an alternative approach to RF ablation that can reduce some of the thermal risks associated with RF ablation. However, operating a cryoablation device and selectively applying cryoablation are generally more difficult than RF ablation. Therefore, cryoablation is not feasible in certain anatomical shapes that can be reached by electrical ablation devices.

[0022] The present disclosure may include electrodes configured for RF ablation, cryoablation, and / or irreversible electroporation (IRE). IRE may be referred to interchangeably throughout this disclosure as pulsed electric field (PEF) ablation and pulsed field ablation (PFA). IRE, as discussed in this disclosure, is a non-thermal cell death technique that can be used to ablate atrial arrhythmias. To ablate using IRE / PEF, biphasic voltage pulses are applied to destroy myocardial cellular structures. The biphasic pulses are non-sinusoidal waveforms that can be tailored to target cells based on the electrophysiology of the cells. In contrast, to ablate using RF, a sinusoidal voltage waveform is applied to generate heat in the treatment area, indiscriminately heating all cells within the treatment area. Therefore, IRE has the ability to spare adjacent heat-sensitive structures or tissues, which may be beneficial in reducing potential complications known with ablation or isolation modalities. Additionally or alternatively, monophasic pulses may be utilized.

[0023] Refer to FIG. 1 , which illustrates an exemplary catheter-based electrophysiology mapping and ablation system 10. The system 10 includes multiple catheters that are percutaneously inserted by a physician 24 through the vascular system of a patient 23 and into a chamber or vasculature of a heart 12. Typically, a delivery sheath catheter is inserted into the left or right atrium near a desired location in the heart 12. Multiple catheters may then be inserted into the delivery sheath catheter to reach the desired location. The multiple catheters may include catheters dedicated to sensing intracardiac electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. An exemplary catheter / medical probe 14 configured to sense IEGMs is illustrated herein. To sense a target site within the heart 12, the physician 24 brings the catheter shaft with an end effector (i.e., multi-layered distal tip / distal tip 28) of the catheter 14 into contact with the heart wall. For ablation, the physician 24 similarly delivers the distal end of the ablation catheter to the target site for ablation.

[0024] The catheter 14 is an exemplary catheter that includes one, and preferably multiple, electrodes 102 configured to sense IEGM signals, optionally distributed over an end distal tip 28 coupled to the catheter shaft, as described in more detail below. The catheter 14 may additionally include a position sensor embedded in or near the end distal tip 28 to track the position and orientation of the distal tip 28. Optionally and preferably, the position sensor is a magnetic-based position sensor including multiple magnetic coils for sensing three-dimensional (3D) position and orientation.

[0025] The magnetic-based position sensor may operate in conjunction with a location pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field within a predetermined working volume. The real-time position of the end effector 100 of the catheter 14 may be tracked based on the magnetic field generated by the location pad 25 and sensed by the magnetic-based position sensor. Details of magnetic-based position sensing technology are described in U.S. Pat. Nos. 5,391,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, and 6,892,091, each of which is incorporated herein by reference.

[0026] The system 10 includes one or more electrode patches 38 positioned for skin contact on the patient 23 to establish a position reference for the location pads 25 and impedance-based tracking of the electrodes 102. For impedance-based tracking, current is directed to the electrodes 102 and sensed at the electrode skin patches 38, thereby allowing the location of each electrode to be triangulated via the 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, each of which is incorporated herein by reference.

[0027] Recorder 11 displays electrograms 21 captured by body surface ECG electrodes 18 and intracardiac electrograms (IEGMs) captured by electrodes 102 on catheter 14. Recorder 11 may include pacing capability for pacing the cardiac rhythm and / or may be electrically connected to a stand-alone pacer.

[0028] The system 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more electrodes 160A, 160B at the end effector of a catheter configured for ablation. The energy generated by the 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, such as may be used to perform irreversible electroporation (IRE), or a combination thereof.

[0029] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheters, the electrophysiology equipment, a power source, and a workstation 55 that controls the operation of the system 10. The electrophysiology equipment of the system 10 may include, for example, multiple catheters, location pads 25, body surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 additionally includes processing capabilities for implementing real-time calculations of catheter position and performing ECG calculations.

[0030] The workstation 55 includes a processor unit having memory, memory or storage loaded with appropriate operating software, and user interface functionality. The workstation 55 may optionally provide multiple functions, including: (1) modeling the endocardial anatomical structure in three dimensions (3D) and rendering the model or anatomical map 20 for display on the display device 27; (2) displaying activation sequences (or other data) compiled from recorded electrograms 21 in a representative visual representation or image superimposed on the rendered anatomical map 20 on the display device 27; (3) displaying the real-time position and orientation of multiple catheters within the cardiac chambers; and (4) displaying areas of interest, such as where ablation energy is being applied, on the display device 27. One commercially available product embodying elements of the system 10 is available as the CARTO™ 3 system, commercially available from Biosense Webster, Inc., 31 Technology Drive, Suite 200, Irvine, CA 92618.

[0031] 2-3E provide views of one or more portions of a first end effector 100 (as used herein, the term "end effector" is used synonymously with the term "distal tip") configured for insertion into an internal body cavity of a patient. Specifically, FIG. 2 shows an exploded view of the first end effector 100, with its components vertically exploded along the vertical axis 62; FIG. 3A shows the framework 120 of the first end effector 100; FIG. 3B shows the position sensor 140 of the first end effector 100; FIG. 3C shows the relative positioning of the distal end of the position sensor 140 with the distal end of the framework 120 (with the bridge 148 removed / omitted); FIG. 3D shows the relative position of the distal end of the position sensor 140 of FIG. 3B (including the bridge 148); and FIG. 3E shows a second flexible circuit 150 disposed on the position sensor 140 and framework 120 (with the insulating material 130 obscuring the view of the position sensor 140 and framework 120). The opposing first flexible circuit 110 is identically designed in this example, and therefore any description of the first flexible circuit 110 will also accurately describe the configuration of the second flexible circuit 150 unless specifically stated to the contrary.

[0032] The first end effector 100 extends from a proximal end (top right in FIG. 2 ) that connects to the elongate shaft 14A ( FIG. 1 ) along a longitudinal axis 60 to a distal end (bottom left in FIG. 2 ). The first flexible circuit 110 (and the second flexible circuit) include multiple electrodes 160A, 160B. In some examples, the term “flexible circuit” includes thin-film circuits, flexible printed circuit boards, thin-film deposition by lithography and etching processes on substrates such as polyimide, copper, liquid crystal polymer (LCP), nitinol substrates, thermoplastic polyurethane (TPU), silicone, thermoset resin, or other polymer substrates. In some examples, the flexible circuit layer described herein can be made primarily of polyimide. In other examples, it can be made of biocompatible polyimide, glass-reinforced epoxy laminate material, copper, or graphene, either alone or in combination. In some examples, the electrodes 160A, 160B described herein can include at least one mapping electrode and / or at least one ablation electrode and can be configured to detect electrophysiological signals or deliver ablation energy AC or DC from the energy generator to tissue in accordance with the various ablation methods mentioned above, e.g., RF, IRE, etc. The structure of the first flexible circuit 110 (and similarly, the second flexible circuit 150) is discussed in further detail with respect to FIG. 3D below.

[0033] The first end effector 100 may further include a framework 120 that is contiguous with or within the insulating material 130. In examples in which the distal tip 28 includes the framework 120, the framework 120 may be disposed directly on the first flexible circuit 110 (or both the first flexible circuit 110 and the second flexible circuit 150), with no or little insulating material 130 disposed between the two. In other examples, an insulating layer of the insulating material 130 may space the framework 120 from the flexible circuits 100, 150. In some examples, the framework 120 is disposed within the insulating material 130 and is substantially planar along the longitudinal axis 60, such that the longitudinal axis 60 is parallel to or coincident with the framework 120. In some examples, the framework is symmetrical with respect to the longitudinal axis 60. In some examples, the framework 120 is formed from a flexible, resilient material. By way of example, the framework may be formed from a shape memory alloy such as nickel-titanium, also known as nitinol, cobalt chromium, stainless steel, and / or other alloys that exhibit pseudoelastic and / or superelastic properties. The framework 120 may be formed from a planar or cylindrical stock of material using any suitable method. For example, the framework 120 may be formed by cutting, laser cutting, stamping, etc.

[0034] 3A , framework 120 includes a base 122, a plurality of spines 124A-124E extending therefrom along longitudinal axis 60, and a plurality of supports 126A-126D connecting adjacent spines 124A-124E. In some examples, there are five cantilevered spines (i.e., a first cantilevered spine 124A, a second cantilevered spine 124B, a third central cantilevered spine 124C, a fourth cantilevered spine 124D, and a fifth cantilevered spine 124E). However, other numbers of cantilevered spines can be used without departing from the spirit and scope of the present disclosure. Furthermore, it should be noted that spines 124A-124E are cantilevered because their distal-most tips / ends are unsupported / unanchored. In some examples, the spines 124A-124E may be supported at their most distal tips / ends (ie, they are not cantilevered).

[0035] The base 122 connects to the elongate shaft 14A and extends distally from the elongate shaft 14A along the longitudinal axis 60. The framework base 122 generally aligns with and supports the bases 112 of the flexible circuits 110, 150.

[0036] First cantilevered spine 124A (also referred to herein as “first spine”) extends from base 112 along longitudinal axis 60 to an unsupported, distal-most end. First cantilevered spine 124A includes: (1) a first segment 124A1 extending from base 112 at an oblique angle to longitudinal axis 60; (2) a second segment 124A2 extending from first segment 124A1 generally parallel to longitudinal axis 60; and (3) a third segment forming a terminal portion 124A3 that includes (i) an eyelet 124A3 and (ii) the unsupported, distal-most end of first cantilevered spine 124A. Eyelet 124A3 helps support other subcomponents of first end effector 100 and is described in more detail below.

[0037] The second cantilevered spine 124B (also referred to herein as the "second spine") extends from the base 112 along the longitudinal axis 60 to an unsupported distal-most end. The second cantilevered spine 124B includes: (1) a first segment 124B1 extending from the base 112 generally parallel to the longitudinal axis 60; (2) a second segment 124B2 extending from the first segment 124B1 at an oblique angle to the longitudinal axis 60; (3) a third segment 124B3 extending from the second segment 124B4 generally parallel to the longitudinal axis 60; and (4) an eyelet 124B. (4) a fourth segment 124B4 extending from third segment 124B3, including third segment 124B4, (5) a fifth segment 124B5 extending from fourth segment 124B4 generally parallel to longitudinal axis 60, and (6) a sixth segment forming a terminal portion 124B6 including (i) another eyelet 124B6, and (ii) the unsupported distal-most end of first cantilevered spine 124A. Eyelet 124B6 helps to support other sub-components of first end effector 100 (described in more detail below).

[0038] The third cantilevered spine 124C (also referred to herein as the “third spine”) is centrally located relative to two of the first and second cantilevered spines 124A, 124B and the fourth and fifth cantilevered spines 124D, 124E. It extends from the base 112 to an unsupported distal-most end. The third cantilevered spine 124C includes: (1) a first segment 124C1 extending from the base 112 generally parallel to or coaxial with the longitudinal axis 60; and (2) a second segment forming a terminal portion 124C2 including (i) an eyelet 124C2 having an elongated shape relative to the aforementioned eyelets 124A3, 124B4, 124B6, and (ii) an unsupported distal-most end. The elongated eyelet 124C2 overlaps distally / along the longitudinal axis 60 with the first eyelet 124B4 and the second eyelet 124B6 of the second cantilevered spine 124B.

[0039] The fourth cantilevered spine 124D (also referred to herein as the “fourth spine”) extends from the base 112 along the longitudinal axis 60 to its unsupported, distal-most end and is generally symmetrical to the second cantilevered spine 124B with respect to the longitudinal axis 60. The fourth cantilevered spine 124D includes: (1) a first segment 124D1 extending from the base 112 generally parallel to the longitudinal axis 60; (2) a second segment 124D2 extending from the first segment 124D1 at an oblique angle to the longitudinal axis 60; (3) a third segment 124D3 extending from the second segment 124D4 generally parallel to the longitudinal axis 60; and (4) an eyelet 124B. (4) a fourth segment 124D4 extending from the third segment 124D3, (5) a fifth segment 124D5 extending from the fourth segment 124D4 generally parallel to the longitudinal axis 60, and (6) a sixth segment forming a terminal portion 124B6 including (i) another eyelet 124D6 and (ii) the unsupported distal-most end of the fourth cantilevered spine 124D. The eyelet 124D3 helps to support other sub-components of the first end effector 100 (described in more detail below).

[0040] The fifth cantilevered spine 124E (also referred to herein as the “fifth spine”) extends from the base 112 along the longitudinal axis 60 to an unsupported, distal-most end and is generally symmetrical to the first cantilevered spine 124A relative to the longitudinal axis 60. The fifth cantilevered spine 124E includes: (1) a first segment 124E1 extending from the base 112 at an oblique angle to the longitudinal axis 60; (2) a second segment 124E2 extending from the first segment 124E1 generally parallel to the longitudinal axis 60; and (3) a third segment forming a terminal portion 124E3 that includes (i) an eyelet 124E3 and (ii) the unsupported, distal-most end of the fifth cantilevered spine 124E. Eyelet 124E3 helps support other sub-components of first end effector 100 and will be described in more detail below.

[0041] As described above, a plurality of supports 126A-126D interconnect each adjacent spine 124A-124E. Specifically, the supports include a first support 126A, a second support 126B, a third support 126C, and a fourth support 126D. These supports 126A-126D extend distally from one spine to another at an oblique (i.e., non-perpendicular) angle relative to the longitudinal axis 60.

[0042] A first support 126A connects an eyelet 124A3 (i.e., a distal portion) of the first spine 124A with an eyelet 124B4 (i.e., a middle portion) of the second spine 124B. A second support 126A connects another eyelet 124B6 (i.e., a distal portion) of the second spine 124B with an elongated eyelet 124C2 (its middle portion) of the third spine 124C. The third support 126C is symmetrically mirrored to the second support 126B and connects the elongated eyelet 124C2 of the third spine 124C with an eyelet 124D6 of the fourth spine 124D. The fourth support 126D is mirrored to the first support 126A and connects another eyelet 124D6 of the fourth spine 124D with an eyelet 124E3 of the fifth spine 124E.

[0043] 3A, the first and second supports 126A, 126B are substantially parallel to one another, which is optimal in this embodiment for supporting the multiple parallel branch segments 114 of the flexible circuit 110, 150 and reducing stiffness. Additionally, the first segment 124A1 of the first spine 124A and the second segment 124B2 of the second spine 124B are substantially parallel to the first and second supports 126A, 126B. Similarly, the third support 126C and the fourth support 126D are substantially parallel to one another, and the first segment 124E1 of the fifth spine 124E and the second segment 124D2 of the fourth spine 124D are also parallel to one another.

[0044] In some examples, each support 126A-126E includes a pair of legs that define a gap (similar to an eyelet) between them and connect the respective segments of the spine. In other examples (such as the example shown in FIG. 5A and described in more detail below), supports 126A-126E are single legs.

[0045] 2 and 3B, a position sensor 140 may be provided sandwiched between the second flexible circuit 150 (or first flexible circuit 110) and the framework 120, generally parallel thereto, and spaced apart therefrom along the vertical axis 62. In this example, the position sensor 140 is configured as a flexible circuit (e.g., similar to the flexible circuits 110, 150, but without electrodes formed thereon) having one or more loops 140A, 140B each having a trace that, when exposed to a magnetic field, induces a current indicative of the position of the first end effector 100.

[0046] The position sensor 140 includes a base 142, a first side section 144A laterally offset from the longitudinal axis 60, a second side section 144B laterally offset from the longitudinal axis 60, a central segment 146 extending along the longitudinal axis 60, and a bridge 148. The bridge 148 functions primarily to add structural integrity to the position sensor 140 during lamination (to prevent movement of the side sections 144A, 144B and the central segment 146). Additionally, holes formed in the bridge 148 can serve as rivets and / or anchor points for better adhesion to the insulating material 130.

[0047] The first side section 144A includes a first segment 144A1 extending obliquely from the base 142 relative to the longitudinal axis 60, a second segment 144A2 extending generally parallel to the longitudinal axis 60 from the first segment 144A1, a first side curved connecting portion 144A3 connected to the second segment 144A2, a third segment 144A4 connected to the first side curved connecting portion 144A3 and extending therefrom, and a third segment 144A5 connected to the third segment 144A4. The first side section 144B includes a second first side curved connection portion 144A5 connected to the second first side curved connection portion 144A5, a fourth segment 144A6 connected to and extending from the second first side curved connection portion 144A5, a third first side curved connection portion 144A7 connected to the fourth segment 144A6, a fifth segment 144A8 connected to and extending from the third first side curved connection portion 144A7, and a sixth segment 144A9 extending from the fifth segment 144A8 and connecting to the central segment 144B. In some examples, the second segment 144A2, the fourth segment 144A6, and the sixth segment 144A9 are substantially parallel to each other, and the third segment 144A4 and the fifth segment 144A8 are substantially parallel to each other. In some examples, the segments of the first side section 144B are linear.

[0048] The second side section 144B includes a first segment 144B1 extending obliquely from the base 142 relative to the longitudinal axis 60, a second segment 144B2 extending generally parallel to the longitudinal axis 60 from the first segment 144B1, a first second side curved connecting portion 144B3 connected to the second segment 144B2, a third segment 144B4 connected to the first second side curved connecting portion 144B3 and extending therefrom, and a second segment 144B5 connected to the third segment 144B4. The second side section 144B includes a second second side curve connection portion 144B5 connected to the second second side curve connection portion 144B5, a fourth segment 144B6 connected to and extending from the second second side curve connection portion 144B5, a third second side curve connection portion 144B7 connected to the fourth segment 144B6, a fifth segment 144B8 connected to and extending from the third second side curve connection portion 144B7, and a sixth segment 144B9 extending from the fifth segment 144B8 and connecting to the central segment 144B. In some examples, the second segment 144B2, the fourth segment 144B6, and the sixth segment 144B9 are substantially parallel to each other, and the third segment 144B4 and the fifth segment 144B8 are substantially parallel to each other. In some examples, the segments of the second side section 144B are linear.

[0049] The curved connecting portions of the position sensor 140 described above have a shape that helps the position sensor 140 to fold into a cylindrical shape without breaking when inserted into a sheath and / or insertion tool. As shown in Figure 3B, all of the curved connecting portions have an arc shape with an angle of 180 degrees or more.

[0050] 3C , each curved connecting portion 144A3, 144A5, 144A7, 144B7, 144B5, 144B3 is aligned with a respective eyelet 124A3, 124B4, 124B6, 124D4, 124D6, 124E3 of framework 120 along vertical axis 62 of first end effector 100 such that the eyelet provides additional support to the curved connecting portion. Similarly, supports 126A-126D extend parallel to and align with particular segments of first and second side sections 144A, 144B of position sensor 140 (e.g., segments 144A4, 144A8, 144B4, and 144B8). Note that all relevant elements have been previously labeled in Figures 3A and 3B, respectively, and only a few elements are labeled in Figure 3C for reference, as the intent of Figure 3C is to show the relative positioning between position sensor 140 and framework 120.

[0051] 3C , the distal-most ends of first and second side sections 144A, 144B (e.g., curved connecting portions 144A7, 144B7) are spaced a predetermined distance D1 from the distal-most end of framework 120. In some examples, predetermined distance D1 is approximately 1 millimeter, which helps position sensor 140 avoid the distal end of first end effector 100, which is subject to high strain. In some examples, bridge 148 ( FIGS. 3B and 3D ) forms the distal-most portion of the position sensor and connects to some of the curved connecting portions (e.g., portions 144A3, 144A7, 144B3, 144B7). As can be seen in FIG. 3D, in examples where the bridge 148 is not omitted (e.g., the configuration shown in FIG. 3C), the distal ends of the first and second side sections 144A, 144B are still spaced a predetermined distance D1 from the distal end of the framework 120, and the bridge 148 runs along or near the distal end of the framework.

[0052] As seen in FIG. 3B and indicated by the equally sized phantom lines, position sensor 140 further includes a pair of side position sensing loops 140A (long-dashed phantom lines) and 140B (short-dashed phantom lines) arranged generally symmetrically about longitudinal axis 60, extending along the aforementioned side segments 144A1-144A8, 144B1-144B8 and central segment 146 of position sensor 140. Generally, each side loop 140A, 140B loops along longitudinal axis 60 from a proximal portion of framework 120 to a distal portion of framework 120 and back to the proximal portion of framework 120 (see FIG. 3C for reference). A first loop 140A extends along first side section 144A and central segment 146, and a second loop 140B extends along second side section 144B and central segment 146.

[0053] 3E, the flexible circuits 110, 150 are disposed within an insulating material 130 extending along the planar longitudinal axis 60. The insulating material 130 can be continuous with the contact surfaces such that only the contact surfaces of at least some of the electrodes 160 are exposed to the ambient environment. As used herein, "ambient environment" refers to the organ in which the first end effector 100 is disposed or the external environment, such as an operating room, prior to placement within the biological organ. The insulating material 130 at least partially encapsulates and spaces apart the different layers of the first end effector 100 (e.g., the flexible circuits 100, 150, the position sensor 140, and the framework 120, which are described in more detail below) along the vertical axis 62.

[0054] The insulating material 130 may include one or more sheets fused together adjacent the framework 120 into a single, continuous, generally planar insulating mass 130. This insulating material 130 also serves to enhance the atraumatic nature of the end effector tip 100 and to protect the subject from sharp edges. The insulating material 130 may include a polymer. The insulating material 130 may be thermoformed around at least a portion of the first flexible circuit 110, the second flexible circuit 150, and the framework 120. The polymer may include TPU or other thermoforming or molding material suitable for such thermoforming.

[0055] Additionally, although the insulating material 130 is shown as flat in these figures, the insulating material 130 may be shaped, corrugated, ribbed, raised, concave, convex, or otherwise configured such that the overall contour of the insulating material 130 provides the physical and / or mechanical properties, such as stiffness and flexure along multiple axes, required by the distal tip 28 referred to above.

[0056] The flexible substrate of each flexible circuit 110, 150 comprises a biocompatible material, extends along a plane, and has a first side and a second side. In some examples, the flexible substrate is formed entirely or almost entirely from the biocompatible material. Electrodes 160 are disposed on a surface of the flexible substrate. In some examples, electrodes 160 are disposed on only one side of the substrate. In other words, electrodes 160 are oriented to face away from framework 120.

[0057] 2 and 3E, each flexible circuit 110, 150 includes a plurality of electrodes 160A (on the first flexible circuit 110), 160B (on the second flexible circuit 150), a base 112 including a soldering pad area disposed at its proximal end, a plurality of branch segments 114A-114G extending from the base 112, a plurality of voids 113A-113J defined between the branch segments 108A-108C, and a connecting bridge 116.

[0058] The central branch segment 114D of the branch segment 114 extends along the longitudinal axis 60, and the outer branch segments 114A, 114B, 114C, 114E, 114F, 114G extend from the base 112 in a direction away from the longitudinal axis 60 and then generally parallel thereto. The electrodes 160A can be positioned along the branch segments 114B-114F such that they are aligned with the electrodes 160A on adjacent branch segments 114B-114F along the longitudinal axis 60. In other examples (e.g., FIG. 6A ), the electrodes 160A may not be aligned (i.e., staggered) with respect to the electrodes 160A on adjacent branches 114B-114F transversely to the longitudinal axis 60, such that the electrodes are positioned in an alternating aligned pattern from branch segment to branch segment.

[0059] Additionally, the branch segments include connecting outer segments 114A, 114G that do not include electrodes 160 A. Rather, these segments 114A, 114G help define the shape of the first end effector 100 and provide reinforcement / protection to the segments of the flexible circuit 110 that carry the electrical traces and / or electrodes 160.

[0060] As seen in FIG. 3E , the configuration of the different layers of the first end effector 100 (e.g., the flexible circuits 110, 150, the position sensor 140, the insulating material 130, and the framework 120) results in multiple voids 113A-113J being defined between each section of the first end effector 100. Specifically, voids 113A-113J (i.e., areas not covered by any material) are defined between each branch segment 114A-114G of the flexible circuit 110. Furthermore, these voids are further subdivided into regions where the supports of the framework 120 extend (e.g., the first support 126A results in two voids 113B, 113C between the outer branch segments 114B, 114C). This reduction in material helps facilitate folding the first end effector 100 into a sheath and / or insertion tool.

[0061] As shown in FIG. 4, eyelets 124A3, 124B4, 124B6, 124D4, 124D6, 124E3, in addition to aligning with curved connecting portions 144A3, 144A5, 144A7, 144B7, 144B5, 144B3 of position sensor 140, also generally align with at most electrodes 160A, thereby providing them with additional support and more evenly distributing forces generated by flexible circuit 110.

[0062] It should be noted that not all of the electrodes 160A on the first end effector 110 described herein need be exposed through the insulating material 130, as these unexposed electrodes may be used to sense far-field signals for noise reduction in proximity to the tissue-contacting electrodes. Similarly, far-field signals containing noise or artifacts may be reduced or canceled for an entire end effector having a reference electrode that is not in contact with tissue, but only with blood.

[0063] 5A-5B, a portion of a second exemplary end effector 200 is shown (similar to the view of FIG. 4) that incorporates similar concepts to those described above with respect to the first end effector 100, such as eyelets and supports within the framework 220, and voids 213A-213L throughout the second end effector 200.

[0064] 5A , the framework 220 of the second end effector 200 includes a base 222, a plurality of spines 224A-224E extending therefrom along the longitudinal axis 60, and a plurality of supports 226A-226D connecting adjacent spines 224A-224E. In some examples, there are five cantilevered spines (i.e., a first cantilevered spine 224A, a second cantilevered spine 224B, a third central cantilevered spine 224C, a fourth cantilevered spine 224D, and a fifth cantilevered spine 124E). However, other numbers of cantilevered spines can be used without departing from the spirit and scope of the present disclosure. Furthermore, as with the previous examples, it should be noted that the spines 224A-224E are cantilevered because their distal-most tips / ends are unsupported / unanchored. In some examples, the spines 224A-224E may be supported at their most distal tips / ends (ie, they are not cantilevered).

[0065] First cantilevered spine 224A (also referred to herein as “first spine”) extends from base 222 to an unsupported, distal-most end along longitudinal axis 60. First cantilevered spine 224A includes: (1) a first segment 224A1 that initially extends from base 222 at an oblique angle to longitudinal axis 60; and (2) a second segment that extends from first segment 224A1 parallel to longitudinal axis 60 and forms a distal portion 224A2 that includes (i) an elongated eyelet 224A2 and (ii) the unsupported, distal-most end of first cantilevered spine 224A. Elongated eyelet 224A2 helps support other subcomponents of second end effector 200 and is described in more detail below.

[0066] The second cantilevered spine 224B (also referred to herein as the “second spine”) extends from the base 222 along the longitudinal axis 60 to an unsupported, distal-most end. The second cantilevered spine 224B includes (1) a first segment 224B1 initially extending from the base 222 at an oblique angle to the longitudinal axis 60, and (2) a second segment extending from the first segment 224B1 parallel to the longitudinal axis 60, the second segment forming a distal portion 224B2 including (i) an elongated eyelet 224B2 and (ii) the unsupported, distal-most end of the second cantilevered spine 224B. The elongated eyelet 224B2 helps support other subcomponents of the second end effector 200 and is described in more detail below.

[0067] The third cantilevered spine 224C (also referred to herein as the “third spine”) is centrally located with respect to two of the first / second cantilevered spines 224A, 224B and the fourth / fifth cantilevered spines 224D, 224E. It extends from the base 222 to an unsupported distal-most end. The third cantilevered spine 224C includes: (1) a first segment 224C1 extending from the base 222 generally parallel to or coaxial with the longitudinal axis 60; and (2) a second segment forming a terminal portion 224C2 including (i) an elongated eyelet 224C2 having an elongated shape, and (ii) an unsupported distal-most end.

[0068] Fourth cantilevered spine 224D (also referred to herein as “fourth spine”) extends from base 222 to an unsupported, distal-most end along longitudinal axis 60 and is generally symmetrical to second cantilevered spine 224B relative to longitudinal axis 60. Fourth cantilevered spine 224D includes (1) an initial first segment 224D1 extending from base 222 at an oblique angle to longitudinal axis 60, and (2) a second segment extending from first segment 224D1 parallel to longitudinal axis 60, the second segment forming a terminal portion 224D2 including (i) an elongated eyelet 224D2 and (ii) the unsupported, distal-most end of fourth cantilevered spine 224D. The elongated eyelet 224D2 helps support other sub-components of the second end effector 200 and will be described in more detail below.

[0069] The fifth cantilevered spine 224E (also referred to herein as the “fifth spine”) extends from the base 222 to an unsupported, distal-most end along the longitudinal axis 60 and is generally symmetrical to the first cantilevered spine 224A relative to the longitudinal axis 60. The fifth cantilevered spine 224E includes (1) a first segment 224E1 initially extending from the base 222 at an oblique angle relative to the longitudinal axis 60, and (2) a second segment extending from the first segment 224E1 parallel to the longitudinal axis 60 and forming a distal portion 224E2 that includes (i) an elongated eyelet 224E2 and (ii) the unsupported, distal-most end of the fifth cantilevered spine 224E. The elongated eyelet 224E2 helps to support other subcomponents of the second end effector 200 and is described in more detail below.

[0070] As described above, a plurality of supports 226A-226D interconnect each adjacent spine 224A-224E. Specifically, the supports include a first support 226A, a second support 226B, a third support 226C, and a fourth support 226D. These supports 226A-226D extend distally from one spine to the other at an oblique (i.e., non-perpendicular) angle relative to the longitudinal axis 60.

[0071] The first support 226A connects the eyelet 224A2 (i.e., the distal portion) of the first spine 224A to the connection region (i.e., the intermediate portion) between the first segment 224B1 and the eyelet 224B2 of the second spine 224B. The second support 226A connects the eyelet 224B2 (i.e., the distal portion) of the second spine 224B to the elongated eyelet 224C2 of the third spine 224C that is more proximal to the base 222 (and thus in the intermediate portion). The third support 226C is symmetrically mirrored to the second support 226B and connects the eyelet 224C2 of the third spine 224C to the eyelet 224D2 of the fourth spine 224D. The fourth support 226D is symmetrically mirrored to the first support 226A and connects the connection region of the fourth spine 224D with the eyelet 124E of the fifth spine 224E2.

[0072] 5A, first support 226A and second support 226B extend substantially parallel. Additionally, proximal portions of first segment 224A1 of first spine 224A and first segment 224B1 of second spine 224B are substantially parallel to first and second supports 226A, 226B. Similarly, third support 226C and fourth support 226D are substantially parallel to each other, and proximal portions of first segment 224E1 of fifth spine 224E and first segment 224D1 of fourth spine 224D are also parallel to each other.

[0073] 5A and 5B, a position sensor 240 may be provided sandwiched between the second flexible circuit 250 (or first flexible circuit) and the framework 220, generally parallel thereto, and spaced apart therefrom along the vertical axis 62. In this example, the position sensor 240 is configured as a flexible circuit (e.g., similar to the flexible circuit 250 but without electrodes formed thereon) having one or more loops 240A, 240B, 240C each having a trace that induces a current indicative of the position of the second end effector 200 when exposed to a magnetic field.

[0074] 5A, multiple segments of position sensor 240 (shown stippled for clarity) extend along portions of framework 220, such as eyelets, to provide support for the position sensor. Similarly, supports 226A-226D extend parallel to and are aligned with particular segments of position sensor 240.

[0075] Referring particularly to FIG. 5B, the position sensor 240 includes a base 242, a first side section 244A laterally offset from the longitudinal axis 60, a second side section 244B laterally offset from the longitudinal axis 60, a first connecting segment 244C1, a second connecting segment 244C2, and a central segment 246 running along the longitudinal axis 60.

[0076] First side section 244A extends from base 242 obliquely relative to longitudinal axis 60 and loops to connect with the distal end of central segment 246. Second side section 244B also extends from base 242 obliquely relative to longitudinal axis 60 and loops to connect with the distal end of central segment 246. First connecting segment 244C1 connects the distal end of base 242 and the intermediate segment of first side section 244A. Second connecting segment 244C2 connects the distal end of base 242 and the intermediate segment of second side section 244A.

[0077] As seen in FIG. 5B and indicated by the phantom lines, position sensor 240 further includes a pair of side position sensing loops 240A (long-dashed phantom lines), 240B (unequally sized phantom lines) arranged generally symmetrically about longitudinal axis 60, running along the aforementioned side sections 244A, 244B and central segment 246. Central loop 240C partially overlaps both side loops 240A, 240B and extends along both connecting segments 244C1, 244C2 and portions of both first and second side sections 244A, 244B. Generally, each loop 240A, 240B, 240C loops along longitudinal axis 60 from a proximal portion of framework 220 to a distal portion of framework 220 and back to the proximal portion of framework 220. The first side loop 240A extends along the first side section 244A and the central segment 246, and the second side loop 240B extends along the second side section 244B and the central segment 246.

[0078] The insulating material 230 and flexible circuit (e.g., second flexible circuit 250) may be configured similarly to the first end effector 100 and, therefore, will not be described in comprehensive detail herein, as an understanding of this example can be derived from the foregoing disclosure. Note that, as best seen in FIG. 5A , electrodes 260 disposed on branches of the flexible circuit 250 extend along / align with eyelets in the framework 220, thereby providing additional support to the electrodes 260. Furthermore, similar to the configuration shown in FIG. 3D , the electrodes 260 can be aligned with electrodes 260 on adjacent branches.

[0079] As seen in FIG. 5A , the configuration of the different layers of second end effector 200 (e.g., flexible circuit 250, position sensor 240, insulating material 230, and framework 220) results in multiple voids 213A-213J defined between respective sections of second end effector 200. Specifically, voids 213A-213J (i.e., areas not covered by any material) are defined between respective branch segments of flexible circuit 250. Furthermore, these voids are further subdivided into regions where supports of framework 220 extend (e.g., first support 226A results in two voids 213B, 213C between the two left outer branch segments of flexible circuit 250). This reduction in material helps facilitate folding of second end effector 200 into a sheath and / or insertion tool.

[0080] Referring now to FIG. 5C, a portion of a modified configuration of a second exemplary end effector 200′ is shown (similar to the view of FIG. 5A) that incorporates similar concepts as those described above with respect to the first end effector 100 and the second end effector 200, such as eyelets and supports within the framework 220, and voids 213A-213L within the entire second end effector 200.

[0081] 5C, the framework 220' of the modified second end effector 200 includes a base 222', a plurality of spines 224A'-224E' extending therefrom along the longitudinal axis 60, and a plurality of supports 226A'-226D' connecting adjacent spines 224A'-224E'. In some examples, there are five cantilevered spines (i.e., a first cantilevered spine 224A', a second cantilevered spine 224B', a third central cantilevered spine 224C', a fourth cantilevered spine 224D', and a fifth cantilevered spine 124E'). However, other numbers of cantilevered spines can be used without departing from the spirit and scope of the present disclosure. Furthermore, as with the previous examples, it should be noted that the spines 224A'-224E' are cantilevered because their distal-most tips / ends are unsupported / unanchored. In some examples, spines 224A'-224E' may be supported at their most distal tips / ends (ie, they are not cantilevered).

[0082] First cantilevered spine 224A' (also referred to herein as "first spine") extends from base 222' to an unsupported, distal-most end along longitudinal axis 60. First cantilevered spine 224A' includes (1) a first segment 224A1' that initially extends from base 222' at an oblique angle to longitudinal axis 60, and (2) a second segment 224A2' that extends from first segment 224A1' parallel to longitudinal axis 60 to a distal portion 224A3' that includes (i) an eyelet 224A3 and (ii) the unsupported, distal-most end of first cantilevered spine 224A'. Eyelet 224A3' helps support other subcomponents of modified second end effector 200' and is discussed in more detail below.

[0083] The second cantilevered spine 224B' (also referred to herein as the "second spine") extends from the base 222' along the longitudinal axis 60 to an unsupported, distal-most end. The second cantilevered spine 224B' includes: (1) a first segment 224B1' that initially extends from the base 222' at an oblique angle to the longitudinal axis 60; and (2) a second segment 224B2' that extends from the first segment 224B1' parallel to the longitudinal axis 60 to a terminal portion 224B3' that includes (i) an eyelet 224B3' and (ii) the unsupported, distal-most end of the second cantilevered spine 224B'. The eyelet 224B3' helps support other subcomponents of the modified second end effector 200' and is described in more detail below.

[0084] The third cantilevered spine 224C' (also referred to herein as the "third spine") is centrally located relative to two of the first / second cantilevered spines 224A', 224B' and the fourth / fifth cantilevered spines 224D', 224E'. It extends from the base 222' to an unsupported distal-most end. The third cantilevered spine 224C' includes: (1) a first segment 224C1' extending from the base 222' generally parallel to or coaxial with the longitudinal axis 60; and (2) a second segment forming a terminal portion 224C2' that includes (i) an elongated eyelet 224C2' having an elongated shape, and (ii) an unsupported distal-most end.

[0085] Fourth cantilevered spine 224D' (also referred to herein as "fourth spine") extends from base 222' to an unsupported, distal-most end along longitudinal axis 60 and is generally symmetrical to second cantilevered spine 224B' relative to longitudinal axis 60. Fourth cantilevered spine 224D' includes (1) a first segment 224D1' that initially extends from base 222' at an oblique angle to longitudinal axis 60, and (2) a second segment 224D2' that extends from first segment 224D1' parallel to longitudinal axis 60 to a terminal portion 224D3' that includes (i) an eyelet 224D3' and (ii) the unsupported, distal-most end of fourth cantilevered spine 224D'. The eyelets 224D3' help support other sub-components of the modified second end effector 200' and are discussed in more detail below.

[0086] Fifth cantilevered spine 224E' (also referred to herein as "fifth spine") extends from base 222' to an unsupported, distal-most end along longitudinal axis 60 and is generally symmetrical to first cantilevered spine 224A' relative to longitudinal axis 60. Fifth cantilevered spine 224E' includes (1) a first segment 224E1' that initially extends from base 222' at an oblique angle to longitudinal axis 60, and (2) a second segment 224E2' that extends from first segment 224E1' parallel to longitudinal axis 60 to a terminal portion 224E3' that includes (i) an eyelet 224E3' and (ii) the unsupported, distal-most end of fifth cantilevered spine 224E'. The eyelets 224A3' help support other sub-components of the modified second end effector 200' and are discussed in more detail below.

[0087] As described above, a plurality of supports 226A'-226D' interconnect each adjacent spine 224A'-224E'. More specifically, the supports include a first support 226A', a second support 226B', a third support 226C', and a fourth support 226D'. These supports 226A'-226D' extend distally from one spine to the other at an oblique (i.e., non-perpendicular) angle relative to the longitudinal axis 60.

[0088] The first support 226A' connects the second segment 224A2' of the first spine 224A' with the connection region (i.e., the middle portion) between the first segment 224B1' and the second segment 224B2' of the second spine 224B'. The second support 226A' connects the eyelet 224B2' (i.e., the terminal portion) of the second spine 224B' with the elongated eyelet 224C2' more proximal to the base 222' (hence, in the middle portion) of the third spine 124C'. The third support 226C' is symmetrically mirrored to the second support 226B' and connects the eyelet 224C2' of the third spine 224C with the eyelet 224D2' of the fourth spine 224D'. The fourth support 226D' is symmetrically mirrored to the first support 226A' and connects the connection region of the fourth spine 224D' with the second segment 224E2' of the fifth spine 124E'.

[0089] The first and second supports 226A', 226B' extend substantially parallel. Additionally, the proximal portions of the first segment 224A1' of the first spine 224A' and the first segment 224B1' of the second spine 224B' are substantially parallel to the first and second supports 226A', 226B'. Similarly, the third support 226C' and the fourth support 226D' are substantially parallel to each other, and the proximal portions of the first segment 224E1' of the fifth spine 224E' and the first segment 224D1' of the fourth spine 224D' are also parallel to each other.

[0090] Continuing with reference to FIG. 5C, a position sensor 240' can be provided sandwiched between, generally parallel to, and spaced apart from the second flexible circuit 250' (or first flexible circuit) and the framework 220' along the vertical axis 62. In this example, the position sensor 240' is configured as a flexible circuit (e.g., similar to the flexible circuit 250 but without electrodes formed thereon) having one or more traces that each induce a current indicative of the position of the modified second end effector 200' when exposed to a magnetic field. The position sensor 240' can be configured similar to or identical to the previously described position sensor 240 of FIG. 5B. Additional features of the modified position sensor 240' include branches 248A' for supporting each loop and tabs 248B' that aid in adhering the position sensor 240A' to the insulating material 230'.

[0091] 5C, multiple segments of position sensor 240 (shown stippled for clarity) extend along portions of framework 220', such as eyelets, to provide support for the position sensor. Similarly, supports 226A'-226D' extend parallel to and are aligned with particular segments of position sensor 240'.

[0092] As seen in FIG. 5C , the configuration of the different layers (e.g., flexible circuit 250′, position sensor 240′, insulating material 230, and framework 220) of modified second end effector 200′ results in multiple voids 213A′-213L′ being defined between each section of second end effector 200. Specifically, voids 213A′-213J′ (i.e., areas not covered by any material) are defined between each branch segment of flexible circuit 250′. Furthermore, these voids are further subdivided into regions through which the branches of position sensor 240′ extend (e.g., left branch 248A′ results in two voids 213B′, 213C′ between the two left outer branch segments of flexible circuit 250′). This reduction in material helps facilitate folding of modified second end effector 200′ into a sheath and / or insertion tool.

[0093] 6A-6C illustrate yet another third exemplary end effector 300 incorporating similar features as those described above. As such, all features of the third end effector 300 will not be described in comprehensive detail, as an understanding of this example can be derived from the foregoing disclosure. For example, similar to the other embodiments, the third end effector 300 includes one or more flexible circuits 310 having electrodes 360, a framework 320, an insulating material 330, and a position sensor 340. In this example, the electrodes 360 are misaligned / staggered, as best seen in FIG. 6A. As partially shown in FIG. 6B, the framework 320 uses multiple spines 324, such as cantilevered spines 324A, that include elongated eyelets to support the branches / electrodes 360 of the flexible circuit 310.

[0094] 6C illustrates a position sensor 340 that may be provided sandwiched between one of the flexible circuits and the framework 320, generally parallel thereto, and spaced apart along the vertical axis 62. In this example, the position sensor 340 is configured as a flexible circuit having three loops 340A, 340B, 340C (similar to the example shown in FIG. 5B) with traces that each induce a current indicative of the position of the second end effector 200 when exposed to a magnetic field.

[0095] 6B , multiple segments of position sensor 340 (shown stippled for clarity) extend along portions of framework 320, such as eyelets, to provide support for position sensor 340. Similarly, supports (not shown) of framework 320 extend parallel to and align with particular segments of position sensor 340.

[0096] Referring particularly to FIG. 6C, position sensor 340 (similar in structure and function to position sensor 240) includes a base 342, a first side section 344A laterally offset from longitudinal axis 60, a second side section 344B laterally offset from longitudinal axis 60, a first connecting segment 344C1, a second connecting segment 344C2, and a central segment 346 extending along longitudinal axis 60.

[0097] First side section 344A extends from base 342 obliquely relative to longitudinal axis 60 and loops to connect with the distal end of central segment 346. Second side section 344B also extends from base 342 obliquely relative to longitudinal axis 60 and loops to connect with the distal end of central segment 346. First connecting segment 344C1 connects the distal end of base 342 and the intermediate segment of first side section 344A. Second connecting segment 344C2 connects the distal end of base 342 and the intermediate segment of second side section 344A.

[0098] As seen in FIG. 6C and indicated by the phantom lines, position sensor 340 further includes a pair of side position sensing loops 340A (long-dashed phantom lines), 340B (unequally sized phantom lines) arranged generally symmetrically about longitudinal axis 60, running along the aforementioned side sections 344A, 344B and central segment 346. Central loop 340C partially overlaps both side loops 340A, 340B and extends along both connecting segments 344C1, 344C2 and portions of both first and second side sections 344A, 344B. Generally, each loop 340A, 340B, 340C loops along longitudinal axis 60 from a proximal portion of framework 320 to a distal portion of framework 320 and back to the proximal portion of framework 320. A first side loop 340A extends along the first side section 344A and the central segment 346, and a second side loop 340B extends along the second side section 344B and the central segment 346.

[0099] 7A-7C illustrate yet another fourth exemplary end effector 400 incorporating similar features as those described above. As such, not all features of the fourth end effector 400 will be described in comprehensive detail, as an understanding of this example can be derived from the foregoing disclosure. For example, similar to the other embodiments, the fourth end effector 300 includes one or more flexible circuits 410 having electrodes 460, a framework 420, an insulating material 430, and a position sensor 440. In this example, the electrodes 460 are misaligned / staggered, as best seen in FIG. 7A.

[0100] The framework 420 uses multiple cantilevered spines 424, each including one or more eyelets for supporting branches / electrodes 460 of the flexible circuit 410. In this example, one or more of the supports 426 connecting adjacent spines may be configured as a pair of supports 426A, 426B extending generally parallel to one another and each having a pair of legs (as in the example described with respect to FIG. 3A ).

[0101] 7B shows the position sensor 440 supported by, generally parallel to, and spaced apart from the framework 420 along the vertical axis 62. In FIG. 7B, other subcomponents of the end effector 400 are shown in phantom to illustrate the relative positioning of the position sensor 440. In this example, the position sensor 440 is configured as a flexible circuit having three loops 440A, 440B, 440C (similar to the example shown in FIG. 6C) each having a trace that induces a current indicative of the position of the second end effector 200 when exposed to a magnetic field.

[0102] As particularly shown in Figure 7B, multiple segments of position sensor 440 extend along portions of framework 420, such as eyelets, to provide support for position sensor 440. Similarly, supports 426A1, 426A2 of framework 420 extend parallel to and are aligned with particular segments of position sensor 440 (as can be seen by comparing Figures 7A and 7B).

[0103] Referring particularly to FIG. 7C, position sensor 440 (similar in structure and function to position sensors 240, 340) includes a base 442, a first side section 444A laterally offset from longitudinal axis 60, a second side section 444B laterally offset from longitudinal axis 60, a first connecting segment 444C1, a second connecting segment 444C2, a central segment 446 extending along longitudinal axis 60, and one or more curved connecting portions 445 connecting the segments of either first side section 444A or second side section 444B.

[0104] More specifically, the first side section 444A extends from the base 442 obliquely relative to the longitudinal axis 60, loops around three turns with curved connecting portions 445, and connects to the distal end of the central segment 446. The second side section 444B also extends from the base 442 obliquely relative to the longitudinal axis 60, loops around three turns with curved connecting portions 445, and connects to the distal end of the central segment 446. The first connecting segment 444C1 connects to the distal end of the base 442 and the intermediate segment of the first side section 444A. The second connecting segment 444C2 connects to the distal end of the base 442 and the intermediate segment of the second side section 444A.

[0105] 7C and indicated by the phantom lines, the position sensor 440 further includes a pair of side position sensing loops 440A (long-dashed phantom lines), 440B (unequally sized phantom lines) arranged generally symmetrically about the longitudinal axis 60, running along the aforementioned side sections 444A, 444B and the central segment 446. The central loop 440C partially overlaps both side loops 440A, 440B and extends along both connecting segments 444C1, 444C2 and portions of both the first and second side sections 444A, 444B. Generally, each loop 440A, 440B, 440C loops along the longitudinal axis 60 from a proximal portion of the framework 420 to a distal portion of the framework 420 and back to the proximal portion of the framework 420. A first side loop 440A extends along the first side section 444A and the central segment 446, and a second side loop 440B extends along the second side section 444B and the central segment 446.

[0106] 8A-11, another aspect of the present disclosure will now be described. Referring to FIGS. 8A-8B, the end effectors (100, 200, 300, 100′) described herein can use a stretchable and / or flexible polymer, such as TPU, as the base substrate layer 110A (e.g., as part of the base 112 and branch 114 of the flexible circuit 110), with the conductive material 111 attached directly to the flexible polymer substrate. Other examples of stretchable and / or flexible polymers suitable for use as the base substrate layer 110A include, but are not limited to, thermoplastic elastomers (TPEs), thermoplastic copolyesters (TPCs), and other thermoplastics, such as thermoplastic vulcanizates (TPVs), silicones, and BEYOLEX™. As used herein, the term “stretchable” refers to a material that can elastically deform. In other words, in some examples, the base substrate layer and / or the flexible circuit can be polyimide-free and LCP-free, which can improve the flexibility and / or stretchability of the overall end effector.

[0107] On the flexible circuit 110, as seen in FIGS. 8A-8B, the conductive material 111 may be routed on (1) the first top surface 110A1, (2) the second bottom surface 110A2, or (3) both surfaces 110A1, 110A2, and connected to electrodes 160 connected to one of the substrate surfaces / layers. As will be appreciated by those skilled in the art, by using a flexible polymer substrate layer 110A, the conductive material 111 (e.g., traces) is therefore the primary limiting factor in strain capability during bending / torsion loads applied to the end effector. Therefore, the technology of the present disclosure includes a flexible circuit 110′ having one or more strain reduction features connected to the substrate layer 110A′ (formed from a flexible polymer, as described above). These strain reduction features are described in more detail in FIGS. 9A-12.

[0108] 9A-9B, a flexible circuit 110′ is shown including multiple branches 114′ along which one or more traces 111′ are routed and connected to electrodes 160. To protect these electrode traces 111′, this example includes one or more sacrificial traces 111A1′, 111A2′ connected to one of the surfaces 110A1′, 110A2′ of the substrate layer 110A′ (e.g., the surface 110A2′ of the substrate layer 110A′ opposite the surface of the electrode traces 111′). As mentioned above, the substrate layer 110A′ may be formed from a stretchable and / or soft polymer, such as TPU, such that the substrate layer 110A′ is flexible and stretchable in three dimensions. The electrode traces 111′ may have a wavy, serpentine pattern, such as that shown in dashed lines in the detailed view forming part of FIG. 9A. To reduce strain on this trace 111', the sacrificial trace 111A2' can have a shallower meander (i.e., a lower frequency undulation / vibration) or can be substantially linear / straight. Alternatively, the sacrificial trace 111A1' can have the same meander / wavy pattern as the electrode trace 111'. These sacrificial traces 111A1', 111A2' are used solely for mechanical functionality by limiting strain on the other electrical traces 111'. Exemplary materials for the sacrificial traces 111A1', 111A2' include, but are not limited to, copper, gold, nitinol, platinum, and combinations thereof.

[0109] 10A-10B, a strain reduction feature of the base 112' is shown, including a termination / solder pad area 112A'. In this region of the substrate layer 110A' opposite the solder pad region 112A', a heat sink 112B' may be connected to the substrate layer 110A' that dissipates heat from the solder pad region 112A' during use. The heat sink 112B' may be configured, for example, as a polyimide layer having a conductive material (e.g., gold, copper, etc.) connected to a second surface 110A2', while the solder pad region 112A' is on a first surface 110A1' of the substrate layer 110A'.

[0110] 11, another strain reduction mechanism is shown embodied as one or more localized stiffeners 115'. The stiffeners 115' may be added to the top or bottom substrate layers 110A1', 110A2' in the areas where the traces 111' run, and may take a variety of forms, such as metal places or polyimide pads.

[0111] FIG. 12 illustrates an exemplary cross-sectional view taken perpendicular to the longitudinal axis 60 of a catheter end effector 100′ including the flexible circuit 110′ of any one of FIGS. 9A-11 described above, having one or more of the strain reduction features described above. The end effector 100′ includes a framework 120 having a plurality of spines 124 extending along the longitudinal axis 60. For example, the framework 120 can have a configuration similar to, but not limited to, that of FIG. 3A. The end effector 100′ further includes two flexible circuits 110′, 150′ facing each other relative to the framework 120, similar to the flexible circuits 110, 150 of the previous examples. The flexible circuit 110' generally includes a substrate layer 110A' formed from a stretchable polymeric material (e.g., TPU, as described above), electrodes 160 connected to the substrate layer 110', conductive traces 111' ( FIG. 9B ) connected to the substrate layer 110A' that conduct current to / from the electrodes 160, one or more of the strain reduction features described above (with respect to FIGS. 9A-11 ), and an insulating material 130 that at least partially encases the framework 120 and the flexible circuit 110'. As will be appreciated by those skilled in the art, other flexible circuits 150' can be configured similarly or identically to the flexible circuit 110'. In some examples, the flexible circuits 110', 150' and framework are suspended within the insulating material 130 such that the framework 120 is spaced apart from the flexible circuits 110', 150' along a vertical axis 62 perpendicular to the longitudinal axis 60.

[0112] FIG. 13 shows a flowchart of an exemplary method 1300 for forming an end effector with a flexible circuit including a stretchable substrate. A framework is formed 1302 that is substantially planar along a longitudinal axis. The flexible circuit is formed 1304 by (i) forming a substrate layer made of a stretchable polymer material (e.g., TPU) and (ii) providing one or more conductive traces (e.g., having a serpentine shape) on the substrate layer. One or more strain reduction features are provided 1306 on the substrate layer of the flexible circuit. The flexible circuit is positioned 1308 over the framework. An insulating material (e.g., TPU) is heated 1310 and reflowed 1312, causing the insulating material to at least partially encase the framework and the flexible circuit.

[0113] In some examples, forming the flexible circuit (1304) can further include providing one or more electrodes on the substrate layer and connecting one or more conductive traces to the one or more electrodes. In this example, the electrodes can be exposed through the reflowed insulating material, for example, by a laser exposure process.

[0114] In some examples, providing one or more conductive traces on a substrate layer can include: depositing a conductive material on the substrate layer; applying a photoresist layer to the conductive material; aligning a photomask over the photoresist layer, the photomask having a conductive trace pattern; exposing the substrate layer to ultraviolet light through the photomask; then removing portions of the conductive material to form the one or more conductive traces, and not removing remaining portions.

[0115] In some examples, the step of providing one or more conductive traces on the substrate layer may include printing a conductive ink on the substrate layer to form the one or more conductive traces.

[0116] FIGS. 14A-14D show various views of another exemplary flexible circuit 110″ including non-nested micro-serpentine traces 111″. FIG. 14A is a schematic layout of the entire flexible circuit 110″, while FIGS. 14B-14D are respective detailed views. Referring to FIG. 14A, the flexible circuit 110″, like the previous example, extends along a longitudinal axis 60 and includes at least a substrate layer 110A″ and a plurality of conductive traces 111″. The flexible circuit 110″ and substrate layer 110A″, like the previous example, have a base 112″ and a plurality of tines 114″ extending from the base 112″. The traces 111″ extend from the base 112″ along respective tines 114″, and each tine 114″ typically includes a plurality of traces 111″ extending therealong. Substrate layer 110A" can include, but is not limited to, any of the stretchable and / or flexible polymers described above with respect to Figures 8A-11. Additionally, any of the strain reduction mechanisms described above (Figures 9A-11) can be used in the construction of flexible circuit 110" shown in Figures 14A-14D. Note further that traces 111" shown in phantom in Figures 14A and 14C represent traces 111" on a different substrate layer than traces 111" shown in solid lines.

[0117] The conductive traces 111″ that carry the electrical current generally extend along the longitudinal axis 60 and are connected to the substrate layer 110A″. As can be seen particularly in FIGS. 14B-14C , the traces 111″ have a serpentine shape and extend generally parallel to, but not overlapping with, one another (for any given cross-section taken along the longitudinal axis 60). Note that this example may incorporate certain features of the previous examples (e.g., stretchable substrate layers, strain reduction features, etc.). Each trace 111″ is routed to and connected to an electrode 160 disposed on the substrate layer 110A″.

[0118] In addition to the above, as can be seen particularly in FIG. 14D , each conductive trace has a wavy, serpentine shape that can be subdivided into a plurality of arc sections 111A″ (indicated by dashed borders for illustrative purposes) connected to one another along longitudinal axis 60. Each arc section 111A″ has an S-shape or an inverted S-shape such that a pair of voids 111B″ are defined therein. The voids 111B″ in each arc section 111A″ have open ends facing in opposite directions due to the serpentine shape of trace 111″.

[0119] As shown in FIGS. 14A-14D, each conductive trace 111″ generally extends along longitudinal axis 60 and has one or more portions / regions extending adjacent to one or more other conductive traces 111″ with a non-overlapping / non-nested relationship. In other words, each arc section 111A″ of any respective conductive trace 111″ is laterally spaced from a gap 111B″ of the arc section 111A″ of any adjacent conductive trace 111″. Each arc section 111A″ is also non-concentric with respect to the adjacent arc section 111A″ of the adjacent trace 111″. In this configuration, the radius of the curve of the arc section 111A″ can be maintained. If they were nested (i.e., containing adjacent sections that are concentric, or in other words, the curve of one trace 111″ is concentric with respect to the adjacent trace), the radius of the adjacent trace 111″ would necessarily be smaller, significantly increasing its stress and fragility.

[0120] Each arc section 111A″ has a linear length LL and an arc length AL that is longer than the linear length. As seen in FIG. 14D , the arc length is defined as the path distance from the midpoint (relative to the trace width TW) of the distal end of the arc section 111A″ to the midpoint (relative to the trace width TW) of the proximal end of the arc section 111A″. In some examples, the ratio of the arc length AL to the linear length LL is approximately 2 to 1. In some examples, each arc length has a value ranging from approximately 0.26 millimeters to 0.32 millimeters. In some examples, each linear length LL has a value ranging from approximately 0.13 millimeters to 0.17 millimeters. In some examples, each arc section 111A″ has an arc section width AW (i.e., the sum / total width of the arc sections 111A″) having a value ranging from approximately 0.12 millimeters to 0.16 millimeters. In some examples, each conductive trace 111″ has a trace width TW having a value ranging from approximately 0.03 millimeters to 0.05 millimeters.

[0121] The techniques of the present disclosure described herein can be further understood in accordance with the following clauses.

[0122] Clause 1. A framework for an end effector of a medical device, the framework comprising: a base configured to connect with an elongate shaft of the medical device, the base extending distally along a longitudinal axis; a first cantilevered spine extending from the base to a distal portion along the longitudinal axis; a second cantilevered spine extending from the base to a distal portion along the longitudinal axis; and a first support connecting the distal portion of the first cantilevered spine with an intermediate portion of the second cantilevered spine; A framework that includes:

[0123] Clause 2. The framework of clause 1, wherein the terminal portion of the first cantilevered spine comprises a first eyelet.

[0124] Clause 3. The framework of clause 2, wherein the first eyelet of the first cantilevered spine comprises an elongated shape.

[0125] Clause 4. A framework according to any one of clauses 2 to 3, wherein the first eyelet of the first cantilevered spine constitutes the distal end of the first cantilevered spine.

[0126] Clause 5. The framework of any one of clauses 1 to 4, wherein the second cantilevered spine comprises a first eyelet.

[0127] Clause 6. The framework of clause 5, wherein the first eyelet of the second cantilevered spine comprises an elongated shape.

[0128] Clause 7. A framework according to any one of clauses 5 to 6, wherein the first support connects the first eyelet of the first cantilevered spine with the first eyelet of the second cantilevered spine.

[0129] Clause 8. The framework of clause 5 or 7, wherein the second cantilevered spine comprises a second eyelet, the second eyelet forming a distal end of the second cantilevered spine.

[0130] Clause 9. The framework of any one of clauses 1 to 8, further comprising a third cantilevered spine extending from the base along the longitudinal axis.

[0131] Clause 10. The framework of clause 9, further comprising a second support connecting a distal portion of the second cantilevered spine with an intermediate portion of the third cantilevered spine.

[0132] Clause 11. A framework described in any one of clauses 9 to 10, wherein the third cantilever spine has an elongated eyelet that overlaps in the distal direction with the first eyelet and the second eyelet of the second cantilever spine.

[0133] Clause 12. The framework of any one of clauses 1 to 11, further comprising a fourth cantilevered spine extending from the base along the longitudinal axis.

[0134] Clause 13. The framework of clause 12, further comprising a third support connecting the intermediate portion of the third cantilevered spine with the distal portion of the fourth cantilevered spine.

[0135] Clause 14. The framework of any one of clauses 1 to 13, further comprising a fifth cantilevered spine extending from the base along the longitudinal axis.

[0136] Clause 15. The framework of clause 14, further comprising a fourth support connecting the intermediate portion of the fourth cantilevered spine with the distal portion of the fifth cantilevered spine.

[0137] Clause 16. The framework of clause 15, wherein the first support and the second support extend substantially parallel to each other, and the third support and the fourth support extend substantially parallel to each other.

[0138] Clause 17. A framework according to any one of clauses 1 to 16, wherein the framework is symmetrical about the longitudinal axis.

[0139] Clause 18. A framework as described in any one of clauses 1 to 17, wherein the first support comprises a pair of segments, each of the pair of segments connecting a distal portion of the first cantilevered spine with a medial portion of the second cantilevered spine.

[0140] Clause 19. The framework of any one of clauses 1 to 18, wherein the first support (i) is at a non-perpendicular angle to the longitudinal axis and (ii) extends distally from the second cantilevered spine to the first cantilevered spine.

[0141] Clause 20. A framework as described in any one of clauses 1 to 19, wherein the second cantilevered spine comprises a segment that extends substantially parallel to the first support.

[0142] Clause 21. A framework according to any one of clauses 1 to 20, wherein the first support comprises a pair of first supports, each first support comprising a pair of segments.

[0143] Clause 22. The framework of any one of clauses 1 to 21, comprising a material having superelastic properties.

[0144] Clause 23. An end effector for a catheter, the end effector comprising: a framework having a base and a plurality of spines extending from the base along a longitudinal axis; a flexible circuit having a plurality of segments extending along the longitudinal axis, the plurality of segments defining areas not covered by any material, the plurality of segments and a plurality of electrodes disposed on each of the segments; and an insulating material disposed between the framework and the flexible circuit such that the framework is spaced from the flexible circuit.

[0145] Clause 24. The end effector of clause 23, further comprising a position sensor comprising a plurality of position sensing loops.

[0146] Clause 25. An end effector as described in Clause 24, wherein the plurality of position sensing loops comprises a pair of side loops arranged generally symmetrically about the longitudinal axis, each side loop extending in a loop from a proximal portion of the insulating material to a distal portion of the insulating material and back along the longitudinal axis to the proximal portion of the insulating material.

[0147] Clause 26. An end effector described in any one of clauses 24 to 25, wherein the plurality of position sensing loops includes a central loop positioned above the longitudinal axis over an area near the distal portion of the insulating material.

[0148] Clause 27. The end effector of clause 26, wherein the central loop partially overlaps each of the side loops.

[0149] Clause 28. An end effector described in any one of clauses 24 to 27, wherein the position sensor comprises a plurality of segments including a first segment and a second segment, and a plurality of curved connecting portions including a first curved connecting portion having an arc shape with an angle of 180 degrees or more and connecting the first segment and the second segment.

[0150] Clause 29. The end effector of any one of clauses 28, wherein the framework comprises a plurality of eyelets, and each curved connecting portion is aligned with a respective eyelet along a vertical direction of the end effector.

[0151] Clause 30. An end effector described in any one of clauses 28 to 29, wherein the multiple segments of the position sensor include multiple linear segments and the framework includes multiple supports, each support (i) connecting a pair of adjacent spines and (ii) extending substantially parallel to and vertically aligned with a respective linear segment of the multiple linear segments.

[0152] Clause 31. An end effector according to any one of clauses 24 to 30, wherein the distal most end of the position sensor is spaced a predetermined distance from the distal most end of the framework.

[0153] Clause 32. An end effector described in any one of clauses 23 to 31, further comprising another flexible circuit arranged generally parallel to the framework and separated from the framework by an insulating material, the other flexible circuit including a plurality of segments, and a plurality of electrodes arranged on the plurality of segments of the other flexible circuit.

[0154] Clause 33. An end effector described in any one of clauses 23 to 31, wherein the electrodes on each segment of the flexible circuit are aligned along the longitudinal axis with other electrodes on other segments of the flexible circuit.

[0155] Clause 34. An end effector described in any one of clauses 23 to 31, wherein the electrodes on each segment of the flexible circuit are staggered alternately along the longitudinal axis with other electrodes on other segments of the flexible circuit.

[0156] Clause 35. An end effector described in any one of clauses 24 to 34, further comprising a bridge (i) forming the distal-most portion of the position sensor and (ii) connecting to some of the plurality of curved connection portions.

[0157] Clause 36. An end effector for a catheter, the end effector comprising: a framework having a base and a plurality of spines extending from the base along a longitudinal axis; and a position sensor spaced from the framework, the position sensor comprising a plurality of position sensing loops, the plurality of position sensing loops comprising a pair of side loops arranged generally symmetrically about the longitudinal axis, each side loop extending in a loop from a proximal portion of the framework to a distal portion of the framework and back along the longitudinal axis to the proximal portion of the framework.

[0158] Clause 37. An end effector as described in Clause 36, further comprising an insulating material disposed between the framework and the position sensor, and wherein the plurality of position sensing loops further comprise a central loop disposed above the longitudinal axis over an area near the distal portion of the insulating material.

[0159] Clause 38. The end effector of clause 37, wherein the central loop partially overlaps each of the side loops.

[0160] Clause 39. An end effector described in any one of clauses 36 to 38, wherein the position sensor comprises a plurality of side segments and a central segment, each side loop extending along the central segment.

[0161] Clause 40. An end effector described in any one of clauses 36 to 39, further comprising a flexible circuit arranged generally parallel to the framework and separated from the framework by an insulating material, the flexible circuit including a plurality of segments, and a plurality of electrodes arranged on the plurality of segments of the flexible circuit.

[0162] Clause 41. An end effector as described in clause 40, wherein the electrodes on each segment of the flexible circuit are aligned along the longitudinal axis with other electrodes on other segments of the flexible circuit.

[0163] Clause 42. An end effector as described in clause 40, wherein the electrodes on each segment of the flexible circuit are staggered alternately along the longitudinal axis with other electrodes on other segments of the flexible circuit.

[0164] Clause 43. A flexible circuit, comprising: a substrate layer comprising a stretchable polymer material; one or more conductive traces connected to the substrate layer and configured to conduct electrical current; and one or more strain reduction features connected to the substrate layer, each strain reduction feature comprising one of a sacrificial trace connected to the substrate layer, a heat sink connected to a base of the substrate layer, or a localized stiffener connected to the substrate layer in a region through which a portion of the one or more conductive traces extend.

[0165] Clause 44. The flexible circuit of clause 43, wherein the one or more strain reduction features include sacrificial traces, the sacrificial traces extending in one of a wavy pattern or a substantially linear direction.

[0166] Clause 45. The flexible circuit of clause 44, wherein the sacrificial trace extends in a wavy pattern, the wavy pattern including the same wavy pattern as the one or more conductive traces.

[0167] Clause 46. The flexible circuit of clause 44, wherein the sacrificial trace extends in a wavy pattern, the wavy pattern including a lower vibration frequency than the wavy pattern of the one or more traces.

[0168] Clause 47. A flexible circuit as described in any one of clauses 44 to 46, wherein one or more conductive traces are connected to a first surface of the substrate layer and a sacrificial trace is connected to an opposite second surface of the substrate layer.

[0169] Clause 48. A flexible circuit as described in any one of clauses 43 to 47, wherein the substrate layer further includes a base, the base including a soldering pad area, and the one or more strain reduction features include a heat sink, the heat sink configured to dissipate heat from the soldering pad area.

[0170] Clause 49. The flexible circuit of clause 48, wherein the solder pad area is connected to a first surface of the substrate layer and the heat sink is connected to an opposite second surface of the substrate layer.

[0171] Clause 50. The flexible circuit of any one of clauses 43 to 49, wherein the one or more strain reduction features comprise a localized stiffener, the localized stiffener comprising one of a metal plate or a polyimide pad.

[0172] Clause 51. The flexible circuit of any one of clauses 43 to 50, wherein one or more conductive traces comprise a serpentine shape.

[0173] Clause 52. A flexible circuit according to any one of clauses 43 to 51, wherein the stretchable polymer material has three-dimensional flexibility.

[0174] Clause 53. A flexible circuit according to any one of clauses 43 to 52, wherein the stretchable polymeric material comprises a thermoplastic polyurethane.

[0175] Clause 54. A flexible circuit as described in any one of clauses 43 to 53, further comprising a plurality of electrodes connected to the substrate layer, each conductive trace of the one or more conductive traces being connected to a respective electrode of the plurality of electrodes.

[0176] Clause 55. An end effector for a catheter, the end effector comprising: a framework having a plurality of spines extending along a longitudinal axis; a flexible circuit, the flexible circuit comprising: a substrate layer including a stretchable polymer material; a plurality of conductive traces connected to the substrate layer and configured to conduct electrical current; a plurality of electrodes connected to the substrate layer, each conductive trace of the plurality of conductive traces connected to a respective electrode of the plurality of electrodes; one or more strain reduction mechanisms connected to the substrate layer, each strain reduction mechanism comprising one of a sacrificial trace connected to the substrate layer, a heat sink connected to a base of the substrate layer, or a localized stiffener connected to the substrate layer in a region where a portion of one or more of the plurality of conductive traces extends; and an insulating material at least partially encasing the framework and the flexible circuit. An end effector comprising:

[0177] Clause 56. An end effector as described in clause 55, wherein the flexible circuit and framework are suspended in an insulating material such that the framework is spaced from the flexible circuit.

[0178] Clause 57. An end effector described in any one of clauses 54 to 56, wherein the one or more strain reduction features include sacrificial traces, the sacrificial traces extending in one of a wave-like pattern or a substantially linear direction.

[0179] Clause 58. An end effector as described in clause 57, wherein the sacrificial trace extends in a wavy pattern, the wavy pattern including the same wavy pattern as the one or more conductive traces.

[0180] Clause 59. An end effector as described in clause 57, wherein the sacrificial trace extends in a wavy pattern, the wavy pattern including a lower vibration frequency than the wavy pattern of one or more traces.

[0181] Clause 60. An end effector described in any one of clauses 57 to 59, wherein one or more conductive traces are connected to a first surface of the substrate layer and the sacrificial trace and the sacrificial trace are connected to an opposite second surface of the substrate layer.

[0182] Clause 61. An end effector described in any one of clauses 55 to 60, wherein the substrate layer further includes a base, the base including a soldering pad area, and the one or more strain reduction mechanisms include a heat sink, the heat sink configured to dissipate heat from the soldering pad area.

[0183] Clause 62. An end effector as described in clause 61, wherein the soldering pad area is connected to a first surface of the substrate layer and the heat sink is connected to an opposite second surface of the substrate layer.

[0184] Clause 63. An end effector described in any one of clauses 55 to 62, wherein the one or more strain reduction mechanisms comprise a localized stiffener, the localized stiffener comprising one of a metal plate or a polyimide pad.

[0185] Clause 64. An end effector as described in any one of clauses 55 to 63, wherein one or more conductive traces comprise a serpentine shape.

[0186] Clause 65. An end effector according to any one of clauses 55 to 64, wherein the stretchable polymer material has three-dimensional flexibility.

[0187] Clause 66. An end effector according to any one of clauses 55 to 65, wherein the elastic polymer material comprises thermoplastic polyurethane.

[0188] Clause 67. A method of manufacturing an end effector for a medical device, the method comprising: forming a framework that is substantially planar along a longitudinal axis; forming a flexible circuit, the flexible circuit comprising: forming a substrate layer comprising a stretchable polymer material; and providing one or more conductive traces on the substrate layer; providing one or more strain reduction features on the substrate layer of the flexible circuit; disposing the flexible circuit on the framework; heating an insulating material; and reflowing the insulating material such that the insulating material encases the framework and the flexible circuit.

[0189] Clause 68. The method of clause 67, wherein forming the flexible circuit further comprises providing one or more electrodes on the substrate layer and connecting one or more conductive traces to the one or more electrodes.

[0190] Clause 69. The method of clause 68, further comprising laser exposing one or more electrodes through the reflowed insulating material.

[0191] Clause 70. The method of any one of clauses 67 to 69, wherein the stretchable polymeric material comprises a thermoplastic polyurethane.

[0192] Clause 71. The method of any one of clauses 67 to 70, wherein the insulating material comprises thermoplastic polyurethane.

[0193] Clause 72. The method of any one of clauses 67 to 71, wherein providing one or more conductive traces on the substrate layer comprises depositing a conductive material on the substrate layer; applying a layer of photoresist to the conductive material; aligning a photomask over the photoresist layer, the photomask including a conductive trace pattern; exposing the substrate layer to ultraviolet light through the photomask; and removing portions of the conductive material to form the one or more conductive traces.

[0194] Clause 73. A method according to any one of clauses 67 to 71, wherein providing one or more conductive traces on the substrate layer comprises printing a conductive ink on the substrate layer to form the one or more conductive traces.

[0195] Clause 75. The method of any one of clauses 67 to 73, wherein one or more conductive traces comprise a serpentine shape.

[0196] Clause 76. A flexible circuit extending along a longitudinal axis, the flexible circuit comprising: a substrate layer; and a plurality of conductive traces connected to the substrate layer and configured to conduct electrical current, each conductive trace having a serpentine shape comprising a plurality of arc sections, each arc section defining a pair of voids having opposite open ends, each conductive trace extending generally along the longitudinal axis adjacent to one or more conductive traces of the plurality of conductive traces such that each arc section of any respective conductive trace of the plurality of traces is laterally spaced from a void of the arc section of an adjacent one or more conductive traces.

[0197] Clause 77. The flexible circuit of clause 76, further comprising a plurality of electrodes connected to the substrate layer, each conductive trace connected to a respective electrode of the plurality of electrodes.

[0198] Clause 78. A flexible circuit as described in any one of clauses 76 to 77, wherein the substrate layer comprises a base and a plurality of tines extending from the base, and the plurality of conductive traces extend from the base along the plurality of tines.

[0199] Clause 79. The flexible circuit of any one of clauses 76 to 78, wherein each arc section includes a straight length and an arc length that is longer than the straight length.

[0200] Clause 80. The flexible circuit of clause 79, wherein the ratio of arc length to linear length is approximately 2 to 1.

[0201] Clause 81. The flexible circuit of any one of clauses 79 to 80, wherein each arc length is within the range of about 0.26 millimeters to 0.32 millimeters.

[0202] Clause 82. The flexible circuit of any one of clauses 79 to 81, wherein each straight length is within the range of about 0.13 millimeters to 0.17 millimeters.

[0203] Clause 83. The flexible circuit of any one of clauses 76 to 82, wherein each arc section comprises a linear width in the range of about 0.12 millimeters to 0.16 millimeters.

[0204] Clause 84. The flexible circuit of any one of clauses 76 to 83, wherein each conductive trace has a trace width in the range of approximately 0.03 millimeters to 0.05 millimeters.

[0205] The above-described embodiments are cited as examples, and the technology of the present disclosure is not limited to what has been specifically shown and described in the above specification. Rather, the scope of the technology of the present disclosure includes both combinations and subcombinations of the various features described above, as well as variations and modifications thereof that would occur to one skilled in the art upon reading the foregoing description and that are not disclosed in the prior art.

[0206] [Embodiment] (1) A framework for an end effector of a medical device, the framework comprising: a base configured to connect to an elongate shaft of the medical device, the base extending distally along a longitudinal axis; a first cantilevered spine extending along the longitudinal axis from the proximal portion to a distal portion; a second cantilevered spine extending along the longitudinal axis from the proximal portion to a distal portion; a first support connecting the distal portion of the first cantilevered spine to an intermediate portion of the second cantilevered spine; A framework that includes: (2) A framework as described in embodiment 1, wherein the terminal portion of the first cantilevered spine is provided with a first eyelet. (3) A framework as described in embodiment 2, wherein the first eyelet of the first cantilever spine has an elongated shape. (4) A framework as described in embodiment 2, wherein the first eyelet of the first cantilevered spine constitutes the distal end of the first cantilevered spine. (5) A framework as described in embodiment 1, wherein the second cantilevered spine includes a first eyelet.

[0207] (6) The framework of claim 1, further comprising a third cantilevered spine extending from the base along the longitudinal axis. (7) The framework of embodiment 6, further comprising a fourth cantilevered spine extending from the base along the longitudinal axis. (8) The framework of embodiment 7, further comprising a fifth cantilevered spine extending from the base along the longitudinal axis. (9) The framework of embodiment 1, wherein the first support comprises a pair of segments, each of which connects the terminal portion of the first cantilevered spine to the intermediate portion of the second cantilevered spine. (10) The framework of embodiment 1, wherein the first support (i) extends at a non-perpendicular angle to the longitudinal axis and (ii) extends in the distal direction from the second cantilever spine to the first cantilever spine.

[0208] (11) An end effector for a catheter, a framework comprising a base and a plurality of spines extending from the base along a longitudinal axis; 1. A flexible circuit comprising: a plurality of segments extending along the longitudinal axis, the plurality of segments defining areas not covered by any material; a flexible circuit comprising: a plurality of electrodes disposed on each of the segments; an insulating material disposed between the framework and the flexible circuit such that the framework is spaced from the flexible circuit; An end effector comprising: (12) An end effector as described in embodiment 11, further comprising a position sensor having a plurality of position sensing loops. (13) The plurality of position sensing loops include: An end effector as described in embodiment 12, comprising a pair of side loops arranged generally symmetrically about the longitudinal axis, each side loop extending in a loop from a proximal portion of the insulating material to a distal portion of the insulating material and back along the longitudinal axis to the proximal portion of the insulating material. (14) The plurality of position sensing loops include: An end effector as described in embodiment 12, comprising a central loop positioned above the longitudinal axis over an area near the distal portion of the insulating material. (15) An end effector as described in embodiment 14, wherein the central loop partially overlaps each of the side loops.

[0209] (16) An end effector for a catheter, comprising: a framework comprising a base and a plurality of spines extending from the base along a longitudinal axis; a position sensor spaced apart from the framework, the position sensor comprising a plurality of position sensing loops, the plurality of position sensing loops comprising: a position sensor comprising a pair of side loops arranged generally symmetrically about the longitudinal axis, each side loop extending in a loop from a proximal portion of the framework to a distal portion of the framework and back along the longitudinal axis to the proximal portion of the framework; An end effector comprising: (17) The present invention further includes an insulating material disposed between the framework and the position sensor, and the plurality of position sensing loops include: An end effector as described in embodiment 16, further comprising a central loop positioned above the longitudinal axis over an area near the distal portion of the insulating material. (18) An end effector as described in embodiment 17, wherein the central loop partially overlaps each of the side loops. (19) An end effector as described in embodiment 16, wherein the position sensor comprises a plurality of side segments and a central segment, and each side loop extends along the central segment. (20) A flexible circuit disposed generally parallel to the framework and separated from the framework by the insulating material, the flexible circuit including a plurality of segments; An end effector as described in embodiment 17, further comprising a plurality of electrodes disposed on the plurality of segments of the flexible circuit.

Claims

1. 1. A framework for an end effector of a medical device, said framework comprising: a base configured to connect to an elongate shaft of the medical device, the base extending distally along a longitudinal axis; a first cantilevered spine extending along the longitudinal axis from the proximal portion to a distal portion; a second cantilevered spine extending along the longitudinal axis from the proximal portion to a distal portion; a first support connecting the distal portion of the first cantilevered spine with an intermediate portion of the second cantilevered spine; A framework that includes:

2. The framework of claim 1 , wherein the distal portion of the first cantilevered spine comprises a first eyelet.

3. The framework of claim 2 , wherein the first eyelet of the first cantilevered spine comprises an elongated shape.

4. The framework of claim 2 , wherein the first eyelet of the first cantilevered spine comprises a distal end of the first cantilevered spine.

5. The framework of claim 1 , wherein the second cantilevered spine comprises a first eyelet.

6. The framework of claim 1 further comprising a third cantilevered spine extending from said base along said longitudinal axis.

7. The framework of claim 6 further comprising a fourth cantilevered spine extending from said base along said longitudinal axis.

8. The framework of claim 7 further comprising a fifth cantilevered spine extending from said base along said longitudinal axis.

9. The framework of claim 1 , wherein the first support comprises a pair of segments, each of the pair of segments connecting the distal portion of the first cantilevered spine with the intermediate portion of the second cantilevered spine.

10. 2. The framework of claim 1, wherein the first support (i) extends at a non-perpendicular angle to the longitudinal axis and (ii) extends in the distal direction from the second cantilevered spine to the first cantilevered spine.

11. 1. An end effector for a catheter, comprising: a framework comprising a base and a plurality of spines extending from the base along a longitudinal axis; 1. A flexible circuit comprising: a plurality of segments extending along the longitudinal axis, the plurality of segments defining areas not covered by any material; a flexible circuit comprising: a plurality of electrodes disposed on each of the segments; an insulating material disposed between the framework and the flexible circuit such that the framework is spaced from the flexible circuit; The end effector comprises:

12. The end effector of claim 11 , further comprising a position sensor comprising a plurality of position sensing loops.

13. The plurality of position sensing loops include:

13. The end effector of claim 12, comprising a pair of side loops generally symmetrically arranged about the longitudinal axis, each side loop extending in a loop from a proximal portion of the insulating material to a distal portion of the insulating material and back along the longitudinal axis to the proximal portion of the insulating material.

14. The plurality of position sensing loops include: The end effector of claim 12 , comprising a central loop disposed above the longitudinal axis over an area near a distal portion of the insulating material.

15. The end effector of claim 14 , wherein the central loop partially overlaps each of the side loops.

16. 1. An end effector for a catheter, comprising: a framework comprising a base and a plurality of spines extending from the base along a longitudinal axis; a position sensor spaced apart from the framework, the position sensor comprising a plurality of position sensing loops, the plurality of position sensing loops comprising: a position sensor comprising a pair of side loops arranged generally symmetrically about the longitudinal axis, each side loop extending in a loop from a proximal portion of the framework to a distal portion of the framework and back along the longitudinal axis to the proximal portion of the framework; The end effector comprises:

17. and a plurality of position sensing loops, each of which is configured to include: The end effector of claim 16, further comprising a central loop disposed above the longitudinal axis over an area near a distal portion of the insulating material.

18. The end effector of claim 17 , wherein the central loop partially overlaps each of the side loops.

19. The end effector of claim 16, wherein the position sensor comprises a plurality of side segments and a central segment, each side loop extending along the central segment.

20. a flexible circuit disposed generally parallel to the framework and separated from the framework by the insulating material, the flexible circuit including a plurality of segments; The end effector of claim 17, further comprising: a plurality of electrodes disposed on the plurality of segments of the flexible circuit.

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