Planar catheter with a flexible circuit including a reinforced section

Abstract

To provide medical probes suitable for use in tissue mapping and ablation. [Solution] The technology of the present disclosure includes a flexible circuit for an end effector of a medical probe. The flexible circuit includes a flexible substrate layer, a plurality of electrodes, and a reinforcing layer. The reinforcing layer is positioned on the first side of the flexible substrate layer within the first zone of the flexible circuit such that, as measured along the vertical axis, the first thickness of the first zone of the flexible circuit is greater than the second thickness of the second zone of the flexible circuit, and the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone of the flexible substrate layer.

Description

Technical Field

[0001] This technology generally relates to medical devices, particularly medical probes having electrodes, and more particularly, but not limited to, medical probes suitable for use in tissue mapping and ablation.

Background Art

[0002] Cardiac arrhythmias such as atrial fibrillation occur when electrical signals abnormally conduct from a region of cardiac tissue to adjacent tissue, thereby disrupting the normal cardiac cycle and causing asynchronous rhythms. Undesired signal sources may be located in atrial or ventricular tissue. Unwanted signals may conduct through cardiac tissue to other locations, causing or continuing an arrhythmia.

[0003] Treatments for treating arrhythmias include surgically interfering with the source of signals causing the arrhythmia and interfering with the conduction paths of such signals. More recently, it has been found that by mapping the electrical properties and cardiac volume of the endocardium and selectively ablating cardiac tissue by applying energy, it is possible to interrupt or modify the propagation of unwanted electrical signals from one part of the heart to another. The ablation process breaks unwanted electrical paths by forming non-conductive damage sites.

[0004] In this two-step procedure, including mapping and subsequent ablation, a catheter equipped with one or more electrical sensors is typically advanced into the heart, and by acquiring data at a number of points, the electrical activity at each point within the heart is sensed and measured. Then, these data are utilized to select the target area where ablation is to be performed.

[0005] For higher mapping resolution, it is desirable that the mapping catheter closely conforms to the target anatomical structure. For mapping within the atria or ventricles (e.g., the apex of the ventricle), it is desirable that the catheter collects more data signals in a shorter time. Furthermore, such catheters should allow sufficient electrode contact with various tissue surfaces, e.g., flat, curved, irregular, or non-planar surface tissues, and should be foldable for non-invasive advancement and retreat through the patient's vascular system. Existing catheters generally require rigid internal structural members to ensure that the predetermined configuration is maintained. This rigidity is disadvantageous during manipulation within body organs, as it can hinder electrode contact with tissue.

[0006] Other catheters may include flexible end-effectors designed to overcome this disadvantage. These catheters may contain layered components that are time-consuming, complex, and expensive to manufacture and assemble. Furthermore, electrical traces and other associated components may be prone to breakage and / or detachment during use. [Overview of the project] [Means for solving the problem]

[0007] The present disclosure provides a flexible circuit for an end effector of a medical probe. The flexible circuit includes a flexible substrate layer, a plurality of electrodes, and a reinforcing layer. The flexible substrate layer extends along a longitudinal axis and comprises a first side and a second side along a vertical axis perpendicular to the longitudinal axis, a plurality of tines extending along the longitudinal axis, a first zone including a portion of at least one of the plurality of tines, and a second zone including another portion of the plurality of tines. The plurality of electrodes are arranged on each of the plurality of tines of the flexible substrate layer. The reinforcing layer is arranged on the first side of the flexible substrate layer and within the first zone of the flexible circuit such that (i) the first thickness of the first zone of the flexible circuit, measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

[0008] Further, the technology of the present disclosure provides an end effector for a medical probe. The end effector comprises an insulating material, a framework, a first flexible circuit, a plurality of electrodes, and a reinforcing layer. The framework is disposed within the insulating material and is substantially planar along a first longitudinal axis. The first flexible circuit is disposed within the insulating material such that it is spaced apart from the framework along a vertical axis perpendicular to the first longitudinal axis. The first flexible circuit comprises a first flexible substrate layer extending along a second longitudinal axis parallel to the first longitudinal axis. The first flexible substrate layer comprises a first side and a second side along a vertical axis perpendicular to the longitudinal axis, a plurality of tines extending along the longitudinal axis, a first zone including a portion of at least one of the plurality of tines, and a second zone including another portion of the plurality of tines. The plurality of electrodes are disposed on each of the plurality of tines of the flexible substrate layer. The reinforcing layer is positioned on the first side of the flexible substrate layer and within the first zone of the flexible circuit such that (i) the first thickness of the first zone of the flexible circuit, measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

[0009] Further, the technology of the present disclosure provides an end effector for a medical probe. The end effector comprises an insulating material, a framework, a first flexible circuit, a plurality of electrodes, and a reinforcing layer. The framework is located within the insulating material and is substantially planar along a first longitudinal axis. The first flexible circuit is located within the insulating material. The first flexible circuit comprises a first flexible substrate layer extending along a second longitudinal axis parallel to the first longitudinal axis. The first flexible substrate layer comprises a first side and a second side along a vertical axis perpendicular to the longitudinal axis, a plurality of tines extending along the longitudinal axis, a first zone including a portion of at least one of the plurality of tines, and a second zone including another portion of the plurality of tines. The plurality of electrodes are located on each of the plurality of tines of the flexible substrate layer. The reinforcing layer is positioned within the first zone of the flexible circuit on the insulating material on the first side of the flexible substrate layer such that (i) the first thickness of the first zone of the flexible circuit, measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

[0010] Methods are further provided according to embodiments of the technology of the present disclosure. The method comprises forming a flexible substrate layer of a flexible circuit. The flexible substrate layer comprises a first surface located on a first side of the flexible substrate layer, a second surface located on a second side of the flexible substrate layer, a plurality of tines, a first zone comprising a portion of at least one of the plurality of tines, and a second zone comprising another portion of the plurality of tines. The method comprises forming a plurality of electrodes on the first surface. The method comprises forming reinforcing layers on the first side of the flexible substrate layer and within the first zone of the flexible circuit such that (i) the first thickness of the first zone of the flexible circuit, measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of a medical system including a medical device, including a medical probe having an end effector equipped with electrodes, based on the disclosed technology. [Figure 2] This is a schematic diagram showing an exploded perspective view of an exemplary end effector using the technology of the present disclosure. [Figure 3] This is a schematic drawing showing a plan view of a flexible circuit including a first reinforcing layer according to the technology of the present disclosure. [Figure 4A] This is a schematic diagram showing a cross-sectional view of a flexible circuit along line 4A-4A in Figure 3 and a portion of the first reinforcing layer, according to the technology of the present disclosure. [Figure 4B] This is a schematic diagram showing a detailed view of Detail A in Figure 4A, based on the technology of this disclosure. [Figure 5A] This is a schematic drawing showing a plan view of a flexible circuit including a second reinforcing layer according to the technology of this disclosure. [Figure 5B] This is a schematic diagram showing a cross-sectional view of the flexible circuit and reinforcing layer in Figure 5A, along line 5B-5B in Figure 5A, according to the technology of the present disclosure. [Figure 5C] This is a schematic diagram showing a cross-sectional view similar to that of Figure 5B of a flexible circuit and an alternative reinforcing layer configuration according to the technology disclosed herein. [Figure 6A] This is a schematic diagram showing a detailed view of a portion of the flexible circuit of Figure 3, which is provided with a modified first or second reinforcing layer according to the technology of the present disclosure. [Figure 6B] This schematic diagram shows a detail view of a portion of the flexible circuit of Figure 3, which is provided with an alternative modified first or second reinforcing layer in accordance with the technology of the present disclosure. [Figure 7] This is a schematic diagram showing a medical probe assembly based on the technology of this disclosure. [Figure 8] This is a flowchart of the manufacturing method using the technology disclosed herein. [Figure 9]This is a schematic diagram showing an exploded perspective view of another exemplary end effector using the technology of the present disclosure. [Figure 10] This is a schematic diagram showing an exploded perspective view of an exemplary end effector, including a reinforcing layer, according to the technology of the present disclosure, as shown in Figure 9. [Modes for carrying out the invention]

[0012] The following detailed description should be read in reference to the drawings, where similar elements in different drawings are numbered identically. The drawings are not necessarily to scale, depict selected embodiments, and are not intended to limit the scope of the invention. The detailed description is illustrative of the principles of the invention, not limiting, but illustrating them as examples. This specification describes several embodiments, adaptations, modifications, alternatives, and uses of the invention, including those that are currently considered to be the best modes for carrying out the invention, which will make it obvious to those skilled in the art how to make and use the invention.

[0013] Where used herein, the terms “about,” “approximately,” or “generally” for any number or range indicate a preferred dimensional tolerance that enables some or all of the components to function for the intended purpose described herein. More specifically, “about,” “approximately,” or “generally” may refer to a range of values ​​within ±20% of the listed values. For example, “about 90%” may refer to a range of values ​​from 71% to 110%. As a further example, “approximately parallel” may refer to a range of values ​​within ±20 degrees of parallel (i.e., an angle of 0 degrees relative to each other). In addition, where used herein, the terms “patient,” “host,” “user,” and “subject” refer to any human or animal subject, and while the use of the subject technology in a human patient represents a preferred embodiment, it is not intended to limit the system or method to human use. Similarly, the term “proximal” indicates a location closer to the operator or physician, while “distal” indicates a location further away from the operator or physician.

[0014] As discussed herein, the vasculature of a "patient", "host", "user", and "subject" can be that of a human or any animal. It should be understood that the animal can be of any of a variety of applicable types, including but not limited to mammals, veterinary animals, livestock animals, or pet animals. As an example, the animal can be a laboratory animal (e.g., rat, dog, pig, monkey, etc.) specifically selected to have certain properties similar to humans. It should be understood that the subject can be, for example, any applicable human patient.

[0015] As discussed herein, an "operator" can include a physician, surgeon, technician, scientist, or any other individual or delivery device associated with the delivery of a multi - electrode catheter for the treatment of drug - refractory atrial fibrillation to a subject.

[0016] The present disclosure relates to systems, methods, uses, and devices for mapping and ablation of heart tissue for treating cardiac arrhythmias. Ablation energy is typically delivered to heart tissue by a tip portion of a catheter capable of delivering ablation energy along the tissue to be ablated. Some exemplary catheters include a three - dimensional structure at the tip portion and are configured to manage ablation energy from various electrodes positioned on the three - dimensional structure. Ablation procedures incorporating such exemplary catheters can be visualized using fluoroscopy.

[0017] Cardiac tissue ablation, which involves applying radiofrequency (RF) energy and thermal techniques such as cryoablation, is a well-known procedure for improving a dysfunctional heart. Typically, to successfully ablate using thermal techniques, it is necessary to measure electrocardiograms at various locations in the myocardium. In addition, temperature measurements during ablation provide data that enables the effectiveness of the ablation. Usually, in ablation procedures using thermal techniques, electrode potentials and temperature are measured before, during, and after the actual ablation. RF approaches can carry risks that can lead to tissue carbonization, combustion, steam popping, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistula. Cryoablation is an alternative approach to RF ablation that can reduce some of the thermal risks associated with RF ablation. However, operating cryoablation equipment and selectively applying cryoablation is generally more difficult than RF ablation. Therefore, cryoablation is not feasible in certain anatomical shapes that can be reached by electroablation equipment.

[0018] This disclosure may include electrodes configured for RF ablation, cryoablation, and / or irreversible electroporation (IRE). Throughout this disclosure, IRE may be interchangeably referred to as pulsed field (PEF) ablation and pulsed field ablation (PFA). The IRE considered in this disclosure is a non-thermal cell death technique that can be used for ablation of atrial arrhythmias. To ablate using IRE / PEF, a biphasic voltage pulse is applied to destroy the cellular structure of the myocardium. The biphasic pulse is a non-sinusoidal waveform and can be tailored to the 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. Thus, IRE has the ability to save adjacent heat-sensitive structures or tissues, which would be beneficial in reducing the potential complications known in ablation or isolation modalities. Additionally or alternatively, monophasic pulses can be utilized.

[0019] Refer to Figure 1, which shows an exemplary catheter-based electrophysiological mapping and ablation system 10. The system 10 includes multiple catheters that are percutaneously inserted by a physician 24 into a lumen or vascular structure of the heart 12 through the vascular system of the patient 23. Typically, a delivery sheath catheter is inserted into the left or right atrium near a desired location in the heart 12. Multiple catheters can then be inserted into the delivery sheath catheter to reach the desired location. The multiple catheters may include a catheter dedicated to sensing intracardiac electrophysiological (IEGM) signals, a catheter dedicated to ablation, and / or a catheter dedicated to both sensing and ablation. An exemplary catheter / medical probe 14 configured to sense IEGM is illustrated herein. To sense a target site in the heart 12, the physician 24 brings the catheter shaft having the distal end 28 (e.g., multilayer end effector 100) of the catheter 14 into contact with the heart wall. For ablation, the physician 24 similarly brings the distal end of an ablation catheter to the target site for ablation.

[0020] Catheter 14 is an exemplary catheter that optionally distributes over an end distal tip 28 coupled to a catheter shaft and includes one or preferably a plurality of electrodes 102 configured to sense IEGM signals, as described in more detail below. Catheter 14 may additionally include a position sensor embedded within 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 that includes a plurality of magnetic coils for sensing three-dimensional (3D) position and orientation.

[0021] The magnetic-based position sensor may operate with a position 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 catheter 14 may be tracked based on the magnetic field generated by the position pad 25 and sensed by the magnetic-based position sensor. Details of magnetic-based position sensing techniques are described in U.S. Patent Nos. 5,391,199; 5,443,489; 5,558,091; 6,172,499; 6,239,724; 6,332,089; 6,484,118; 6,618,612; 6,690,963; 6,788,967; 6,892,091, each of which is incorporated herein by reference.

[0022] System 10 includes one or more electrode patches 38 positioned for skin contact on a patient 23 to establish a position reference for the position pad 25 and impedance-based tracking of the electrodes 102. For impedance-based tracking, a current is directed to the electrodes 102 and sensed in the electrode skin patches 38, thereby allowing the position of each electrode to be triangulated through the electrode patches 38. Details of the impedance-based location tracking technology are described in U.S. Patents 7,536,218, 7,756,576, 7,848,787, 7,869,865 and 8,456,182, each of which is incorporated herein by reference.

[0023] The recorder 11 displays the electrophysiogram 21 captured by the surface ECG electrode 18 and the intracardiac electrophysiogram (IEGM) captured by the electrode 102 of the catheter 14. The recorder 11 may include pacing capabilities for pacing the rhythm of the heart and / or may be electrically connected to a standalone pacer.

[0024] System 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more electrodes 160A, 160B located on 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, radio frequency (RF) energy, pulsed-field ablation (PFA) energy including unipolar or bipolar high-voltage DC pulses that may be used to perform irreversible electroporation (IRE), or a combination thereof.

[0025] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheter, the electrophysiological equipment, the power supply, and the workstation 55 that controls the operation of the system 10. The electrophysiological equipment of the system 10 may include, for example, multiple catheters, position pads 25, 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 calculation of catheter position and performing ECG calculations.

[0026] The workstation 55 includes memory, a processor unit having memory or storage device loaded with appropriate operating software, and user interface functions. The workstation 55 may optionally provide several functions, including (1) modeling the endocardial anatomical structure in three dimensions (3D) and rendering the model or anatomical map 20 for display on a display device 27, (2) displaying activation sequences (or other data) compiled from recorded electrophoresis diagrams 21 on the display device 27 as a representative visual representation or image superimposed on the rendered anatomical map 20, (3) displaying the real-time position and orientation of multiple catheters within the cardiac chambers, and (4) displaying areas of interest on the display device 27, such as the location where ablation energy is being applied. One commercially available product embodying the elements of system 10 is available as the CARTO® 3 system, commercially available from Biosense Webster, Inc., 31 Technology Drive, Suite 200, Irvine, CA 92618.

[0027] Figures 2–4B provide various field diagrams of one or more portions of the end effector 100 (in this specification, the term “end effector” is used synonymously with the term “distal tip”) configured for insertion into the internal body cavity of a patient. In particular, these figures show the end effector 100 including a reinforcing layer 140 (shown by dots in Figures 2 and 3) that reduces stress on the electrical interconnects located in its proximal section. The reinforcing layer 140 helps reduce twisting of the end effector when it bends and deflects during use, and when it folds into the sheath 210 (Figure 7), increasing the bending radius of the proximal section. The following disclosure will reveal to those skilled in the art additional advantages of the described configuration.

[0028] Specifically, Figure 2 shows an exploded view of the first end effector 100, whose components extend along the longitudinal axis 60 of the end effector 100 and are exploded vertically along the vertical axis 62; Figure 3 shows a plan view of the flexible circuit 150 reinforced with a reinforcing layer 140; and Figures 4A and 4B are detailed cross-sectional views of the flexible circuit 150. The opposing flexible circuit 110 is designed similarly or identically in this example. Therefore, any description of the first flexible circuit 150 is understood to also characterize the configuration of the second flexible circuit 110, and vice versa, unless explicitly stated otherwise.

[0029] The end effector 100 extends from a proximal end (upper right in Figure 2) connected to an elongated shaft 230 (Figure 8) to a distal end (lower left in Figure 2) along the longitudinal axis 60, and includes components that are continuous with and / or located within the insulating material 130. The first flexible circuit 150 (and the second flexible circuit 110) of the end effector 100 extends along another longitudinal axis 61 parallel to the entire longitudinal axis 60 of the end effector. The first flexible circuit 150 and the second flexible circuit 110 further include a plurality of electrodes 160 electrically connected to the PIU 30 via electrical interconnects 161 (e.g., electrical traces, see Figure 4A).

[0030] In some embodiments, the term “flexible circuit” includes thin-film circuits, flexible printed circuit boards, and thin-film deposition by lithography and etching processes on substrates such as polyimide, copper, LCP, nitinol substrates, thermoplastic polyurethane (TPU), silicone, thermosetting resins, or other polymer substrates. In some embodiments, the flexible circuit layers described herein can be made primarily from polyimide. In other embodiments, they can be made from biocompatible polyimide, glass-reinforced epoxy laminates, copper, or graphene, either alone or in combination. In some embodiments, the electrode 160 described herein may include at least one mapping electrode and / or at least one ablation electrode, and may be configured to detect electrophysiological signals or to transmit ablation energy AC or DC from an energy generator 50 to the tissue according to various ablation methods mentioned herein, e.g., RF, IRE, etc.

[0031] The second end effector 100 may further include a framework 120 that is continuous with or located within the insulating material 130. In examples where the distal tip 28 includes the framework 120, the framework 120 may be located directly on the first flexible circuit 150 (or both the first flexible circuit 150 and the second flexible circuit 110), with the insulating material 130 being located little to no between the two. This example is illustrated with reference to Figures 9-10. In other words, the two longitudinal axes 60, 61 referred to earlier may be located proximal to each other. In other examples, the insulating layer of the insulating material 130 may cause the framework 120 to be spaced further apart from the flexible circuits 110, 150 such that the longitudinal axes 60, 61 are spaced further apart than in the exemplary configuration described above. In some examples, the framework 120 is located within the insulating material 130 and is substantially planar along the longitudinal axis 60, such that the longitudinal axis 60 is parallel to or coincides with the framework 120. In some examples, the framework 120 is symmetrical with respect to the longitudinal axis 60. In some examples, the framework 120 is formed from a flexible elastic material. For example, the framework can be formed from shape memory alloys such as nickel-titanium, cobalt-chromium, stainless steel, and / or other alloys exhibiting pseudo-elastic and / or superelastic properties, also known as nitinol. The framework 120 can be formed from a planar or cylindrical stock of material using any preferred method. For example, the framework 120 can be formed by cutting, laser cutting, stamping, etc.

[0032] Although not explicitly shown, it should be noted that the layered end effector 100 shown in Figure 2 may also include other layers, such as a position-sensing loop layer for sensing the position and / or shape of the end effector 100.

[0033] As described above, the flexible circuits 110 and 150 are arranged within an insulating material 130 extending along the 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 among the plurality of electrodes 160 are exposed to the ambient environment. As used herein, “ambient environment” refers to the external environment such as the organ in which the first end effector 100 is placed, or an operating room before it is placed inside a biological organ. The insulating material 130 at least partially encapsulates and / or separates different layers of the end effector 100 (e.g., the flexible circuits 110 and 150 and the framework 120) along the vertical axis 62.

[0034] In this example, all electrodes 160 are exposed through the insulating material. Note that all electrodes 160 on the flexible circuits 110, 150 do not need to be exposed through the insulating material 130, as these unexposed electrodes can be used to sense far-field signals for noise reduction in proximity to the tissue contact electrodes. Similarly, far-field signals containing noise or artifacts can be reduced or canceled out against the entire end effector, which has a reference electrode that does not come into contact with tissue and only with blood.

[0035] The insulating material 130 may include one or more sheets that are fused together in close proximity to the framework 120 to form a single, continuous, generally planar insulating mass 130. This insulating material 130 also works to enhance the non-traumaticity of the end effector tip 100 and to protect the object from sharp edges. The insulating material 130 may include a polymer. The insulating material 130 can be thermoformed around the first flexible circuit 150, the second flexible circuit 110, and at least a portion of the framework 120. The polymer may include TPU or other thermoforming or shaping materials suitable for such thermoforming. In some embodiments, the insulating material 130 has a Shore A hardness of about 52 (e.g., a Shore A hardness in the range of 50 to 55).

[0036] Furthermore, although the insulating material 130 is shown as flat in these figures, the insulating material 130 may be shaped, corrugated, undulating, raised, concave, convex, or otherwise configured such that the overall shape of the insulating material 130 provides physical and / or mechanical properties such as rigidity and flexibility along multiple axes required by the distal tip portion 28 / end effector 100 mentioned above.

[0037] Referring specifically to Figures 3 and 4A in relation to each other, the flexible circuit 150 includes a flexible substrate layer 150A and a coverlay 150C connected on both sides to the flexible substrate layer 150A via, for example, an adhesive material layer 150B. As seen in Figure 4A, the flexible substrate layer 150A has a first side (e.g., the upper side as seen in Figure 4A) and a second side (e.g., the lower side as shown in Figure 4A) along the vertical direction VV of the end effector 100 (coaxial with the vertical axis 61 and perpendicular to the longitudinal axis 61). The flexible circuit 150 will be described in detail below, but it should be noted again that all of the following details may or may not apply to the second flexible circuit 110 unless explicitly stated otherwise.

[0038] The flexible substrate layer 150A of the flexible circuit 150 extends along the longitudinal axis 61 of the flexible circuit 150 and contains a biocompatible material. In some embodiments, the flexible substrate layer 150A is formed entirely or almost entirely from a biocompatible material. In some embodiments, the flexible substrate layer is formed from polyimide, copper, LCP, nitinol substrate, thermoplastic polyurethane (TPU), silicone, thermosetting resin, or other polymer substrate. In some embodiments, the flexible substrate layer 150A described herein can be made primarily from polyimide. In other embodiments, it can be made from biocompatible polyimide, glass-reinforced epoxy laminate, copper, or graphene, either alone or in combination.

[0039] The electrode 160 is positioned on the surface of the flexible substrate layer 150A, such as the upper surface (relative to the orientation shown in Figure 4A), and protrudes from there. In some embodiments, the electrode 160 is positioned on only one side of the substrate layer 150A, and the electrical interconnects (such as traces) 161 connected to the electrode and supplying power are routed to the opposite surface / side of the flexible substrate layer 150A (i.e., the lower surface relative to the orientation shown in Figure 4A). In some embodiments, the electrical interconnects 161 can be positioned on both the upper and lower surfaces of the flexible substrate layer 150A.

[0040] Referring to Figure 3, as described above, each flexible circuit 110, 150 may include the following components, with specific reference to flexible circuit 150. The flexible circuit 150 includes a base 151 having a soldering pad area 151A located at its proximal end and a distal end 151B, a plurality of tines 152-156 extending from the base 151 along the longitudinal axis 61, a plurality of gaps 159A-159F defined between the tines 152-156, and a connecting distal segment 158.

[0041] More specifically, the flexible substrate layer 150A and the flexible circuit 150 include a central tine 154 extending along the longitudinal axis 61, and offset tines 152, 153, 155, and 156 offset from the longitudinal axis. The offset tines 152, 153, 155, and 156 extend from the base 151 obliquely away from the longitudinal axis 61, and then generally along / parallel to it. Multiple electrodes 160 are arranged on each tine 152-156. The electrodes 160 can be arranged along the tines 152-156 so as to be aligned with electrodes 160 on adjacent tines 152-156 along the longitudinal axis 60. In other examples, the electrodes 160 do not have to be aligned with respect to electrodes 160 on adjacent tines in the direction across the longitudinal axis 61, so as to be arranged in a pattern of alternating alignment from tine to tine (i.e., they are staggered).

[0042] The tines 152-156 include a first tine 152 extending from the base 151 along the longitudinal axis 61, a second tine 153 extending from the base 151 along the longitudinal axis 61, a third tine 154 extending from the base 151 along the longitudinal axis, a fourth tine 155 extending from the base 151 along the longitudinal axis 61, and a fifth tine 156 extending from the base 151 along the longitudinal axis 61. As can be seen in Figure 3, the first to fifth tines 152-156 are arranged continuously from left to right. The flexible substrate layer 150A and the flexible circuit 150 further include a connecting distal segment 158 ​​that connects the distal ends of the first tine 152, the second tine 153, the third tine 154, the fourth tine 155, and the fifth tine 156.

[0043] Furthermore, the tines include connecting the outer segments 152A and 156A, which do not include the electrode 160. Rather, these segments help define the shape of the end effector 100 and provide reinforcement / protection to the segments of the flexible circuit 150 that carry the electrical trace 161 and / or electrode 160. The tines 152-156, the connecting distal segment 158, and the connecting outer segments collectively define the respective gaps 159A-159F between them (i.e., areas not covered by any material). This reduction in material can help facilitate folding the end effector 100 into the sheath 210 (Figure 7) and / or insertion tool.

[0044] The flexible substrate layer 150A (and the flexible circuit 150 as a whole) is divided into zones. As shown in Figure 3, this example includes first and second zones, namely zone A (first zone) and zone B (second zone). Zone A includes the distal end 151B of the base 151, and the proximal portions of the tines 152-156. In some embodiments, zone A may extend to the nearest end PE of the flexible circuit 150. Zone B includes the distal portions of the tines 152-156, and zones B and A touch / abut each other at their boundaries. Zones A and B are sectioned such that the electrode 160 is not located in zone A but is located in zone B.

[0045] As described above, one or more reinforcing layers 140 are provided on a portion of the end effector 100 in order to minimize twisting of the end effector 100 and / or to reduce strain on the electrical interconnects 161 in the area of ​​the reinforcing layer 140. In some embodiments, the reinforcing layer 140 is associated with both the flexible circuits 110 and 150. However, without departing from the spirit and scope of the present disclosure, the reinforcing layer 140 may be provided with only one of the flexible circuits 110 and 150.

[0046] As seen in Figures 3 and 4A, the reinforcing layer 140 is provided on the first side of the flexible substrate layer 150A (i.e., the upper side of the substrate layer 150A with respect to the orientation in Figure 4A, the same side as the side on which the electrode 160 is provided) and within zone A of the flexible circuit 150. In some embodiments, the reinforcing layer is provided only within zone A and extends to its distal end, so that the reinforcing layer 140 terminates in front of the electrode 160 so that the electrode 160 can conform to the tissue. The first side faces outward from the framework 120 when the flexible circuit 150 is assembled with the remaining components of the end effector 100. This results in asymmetric rigidity of the flexible circuit 150 in zone A with respect to the longitudinal axis 61 in the vertical direction VV of the flexible circuit 150.

[0047] In the embodiment shown in Figures 3 to 4B, the reinforcing layer 140 includes one or more flexible biocompatible material layers 140A and an optional connecting layer 140B that connects the biocompatible material layers 140A to the coverlay 150C. In this embodiment, a single biocompatible material layer 140A is used, but two or more layers 140A (e.g., as shown in Figure 10) may also be used without departing from the spirit and scope of the disclosure. In some embodiments, the reinforcing layer 140 and the substrate layer 150A can form a monolithic structure. In some embodiments, the biocompatible material layer 140A includes polyimide or TPU having a Shore A hardness of about 62 (e.g., in the range of 60 to 65 Shore A hardness). However, any suitable material having a similar Shore A hardness may be used. In this embodiment, due to its higher Shore A hardness (and increased overall thickness), the harder reinforcing layer 140 (compared to the softer insulating material 130 with a lower Shore A hardness) provides a greater bending rigidity to a portion of the flexible substrate layer 150A than to the rest of the end effector 100 that does not have a reinforcing layer, when placed on that portion.

[0048] In some embodiments, the optional connecting layer 140B is an adhesive layer 140B. Of course, any suitable assembly / connecting process can be used. The reinforcing layer 140 is provided in zone A over the distal end 151B of the base 151 and all of the tines 152-156, and the reinforcing layer 140 includes the base 151 overlapping the distal end 151B of the base 151 and the tine portions 142-146 overlapping each portion of the tines 152-156 entering zone A.

[0049] Referring to the detailed view in Figure 4B, in the vertical direction VV of the flexible circuit 150, each component of the flexible circuit 150 has its own thickness. In particular, the flexible substrate layer 150A has a first thickness T1, the coverlays 150C on both sides of the flexible substrate layer 150A each have a second thickness T2, the biocompatible material layer 140A of the reinforcing layer 140 has a third thickness T3, the adhesive material layer 150B has a fourth thickness T4, and the connecting layer 140B has a fifth thickness T5. In some embodiments, the first thickness T1 is approximately 25 microns, the second thickness T2 is approximately 12 microns, the third thickness T3 is approximately 25 microns, the fourth thickness T4 is approximately 12 microns, and the fifth thickness T5 is approximately 25 microns. However, it will be understood that any of T1 to T5 may be in the range of approximately 12 to 50 microns without departing from the spirit and scope of this disclosure.

[0050] In contrast, zone B, which extends along the longitudinal axis 61 from zone A to the most distal end DE of the flexible circuit 150, does not contain the reinforcing layer 140. As a result, the total thickness of zone A of the flexible circuit 150 (i.e., T1 + T2(x2) + T3 + T4(x2) + T5) is greater than the total thickness of zone B of the flexible circuit 150 (i.e., T1 + T2(x2) + T3), and the bending stiffness of zone A is greater than that of zone B. In some embodiments, the maximum thickness of zone A is at least 50% greater than the maximum thickness of zone B (excluding potential protrusions of the electrode 160). In some embodiments, the thickness of zone B is approximately 75 microns, and the thickness of zone A is approximately 125 microns.

[0051] In particular, as seen in Figure 4B, the reinforcing layer 140 has a transition section 145 near zone B where the reinforcing layer 140 terminates. In the examples of Figures 4A and 4B, this transition section 145 has a substantially stepped shape (i.e., the material of the reinforcing layer 140 does not gradually decrease), and the thickness of the reinforcing layer 40 is almost uniform.

[0052] Figures 5A–5C show an alternative configuration 140' of the reinforcing layer 140 (shown as a dot in Figure 5A), where a material / thickness reduction is used to achieve a reinforcing layer that allows for additional flexibility of the flexible circuit 150 at the distal end of the reinforcing layer 140'. In this example, the reinforcing layer 140' extends into a first zone (zones A and B, generally shown as section A) but not into a second zone (zone C, generally also shown as section B) containing the electrode 160. Rather than being of uniform thickness throughout, the first zone is subdivided into zones A and B, and the reinforcing layer 140' spanning zone A may have a uniform thickness, while the reinforcing layer 140' spanning zone B may have transitional sections 145' with different thickness and / or hardness relative to zone A. In some embodiments, this can be achieved by multilayering the reinforcing layer 140' using two or more sheets (described in more detail with respect to Figure 10). As shown in Figure 5B, two sheets 140A.1' and 140A.2' may be laminated within Zone A, with only a single sheet 140A.2' extending into Zone B. Of course, the degree of hardness taper can be further adjusted by using more than two sheets terminating at various positions along the transition section 145'. Alternatively, as shown in Figure 5C, the transition section 145' may have a tapered shape with a gradually decreasing thickness from Zone A to Zone C. These configurations can be used to achieve varying stiffnesses in the proximal section of the end effector, as required by the design. In some embodiments, as shown in Figure 5B, the transition section 145' / Zone B may begin at a point where tines 152-156 are defined and extend from the base 151.

[0053] Figures 6A and 6B show other alternative configurations 140'', 140''' (shown by dots in Figures 6A and 6B) of the reinforcing layer 140 that are consistent with the principles of this disclosure. In these examples, the first zone and reinforcing layer are provided only on specific tines, rather than on all of the tines. For example, as seen in Figure 6A, the reinforcing layer 140'', can span zone A'', which is located only over the central tine 154. As a result, the offset tines 152, 153, 155, and 156 have no reinforcing layer, and only the central tine 154 is reinforced over the rest of the flexible circuit 150 (zone B'',). Similarly, as seen in Figure 6B, another alternative reinforcing layer 140''' can span zone A'''', which is located only over the three central tines 153-155. As a result, the outermost tines 152 and 156 do not have a reinforcing layer, and only the central tines 153 to 155 are reinforced relative to the rest of the flexible circuit 150 (zone B'').

[0054] This disclosure provides a medical probe assembly 200, as shown in Figure 7, which may include a tubular member 230 extending along a longitudinal axis 60 and configured to deliver one of the aforementioned end effectors 100 to the outside of the sheath 210. A physician 24 can operate the medical probe 200 using a handle 220. Suitable examples of the catheter assembly 200, as well as its subcomponents such as the handle 220, the sheath 210, the tubular member 230, and others not mentioned herein, are described in U.S. Patent Application Publication No. 2021 / 0369339, which is incorporated herein by reference.

[0055] In addition to the embodiments described above, referring to Figure 8, a method 800 for manufacturing an end effector for a medical device may include: A flexible substrate layer of a flexible circuit is formed (802). The flexible substrate layer includes a first surface located on a first side of the flexible substrate layer, a second surface located on a second side of the flexible substrate layer, a plurality of tines, a first zone including a portion of at least one of the plurality of tines, and a second zone including another portion of the plurality of tines. A plurality of electrodes are formed on the first side (804). A reinforcing layer is formed on the first side of the flexible substrate layer and within the first zone of the flexible circuit such that (i) the first thickness of the first zone of the flexible circuit is greater than the second thickness of the second zone of the flexible circuit, as measured along the vertical axis, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone (806).

[0056] In some embodiments, forming electrodes on a first surface 804 includes forming electrodes within a second zone of the flexible substrate. In some embodiments, forming a reinforcing layer on a first side of the flexible substrate layer 806 includes bonding a flexible biocompatible material layer to the flexible substrate. In some embodiments, forming the flexible substrate 802 includes bonding a coverlay to the first surface of the flexible substrate. In some embodiments, forming a reinforcing layer on a first side of the flexible substrate layer 806 includes bonding the reinforcing layer to the coverlay. In some embodiments, steps 802 for forming the flexible substrate layer and 806 for forming the reinforcing layer include molding a flexible biocompatible material to form the flexible substrate and the reinforcing layer.

[0057] Other methods may include, but are not limited to, providing a polyimide sheet that is pre-laser cut with an adhesive and placed on the main flexible circuit. Alternatively, a photoimaging coverlay (reinforcement) can be provided that solidifies when exposed to ultraviolet light (rather than the pre-laser cutting process in the alternative methods described above).

[0058] Referring here to Figures 9-10, an alternative configuration 200 of the end effector 100 is shown. In this example, insulating material 230 (equivalent to insulating material 130 described above) is provided as first and second sheets 230A, 230B that are moved from between the flexible circuits 210, 250 (equivalent to flexible circuits 110, 150 described above) and the framework 220 (equivalent to framework 120 described above) along the vertical axis 62 to the outermost part of the end effector 200. As seen in Figure 9, insulating material 230A, 230B includes gaps 232 that expose the electrodes of the flexible circuits 210, 250. In this example, the insulating materials 230A and 230B are laminated as part of the manufacturing process on the outer portion of the end effector (i.e., separated from the framework 220 by the flexible circuits 210 and 250 along the vertical axis 62), so that when the insulating materials 230A and 230B are thermoformed around the first flexible circuits 210 and 250, the second flexible circuit 210, and at least a portion of the framework 220, the insulating materials are hardly or never positioned between the flexible circuit 250 and the framework 220. This configuration of the insulating materials 230A and 230B can be applied to any of the above examples without departing from the spirit and scope of the present disclosure.

[0059] As shown in Figure 10, and / or in conjunction with any of the aforementioned examples described above (for example, with respect to the description of Figures 5A to 5B), a multilayer reinforcing layer 240 can be provided on the insulating materials 230A, 230B. As illustrated, the reinforcing layer 240 can be provided on both the first insulating sheet 230A and the second insulating sheet 230B. Each reinforcing layer may consist of two or more sheets that overlap each other and are fused together with the insulating material 230. In this example, each reinforcing layer includes two biocompatible material layers 240A.1, 240A.2 laminated within the aforementioned zone A in Figure 3. These biocompatible material layers 240A.1, 240A.2 may include polyimide or TPU having a Shore A hardness of about 62 (e.g., in the range of 60 to 65 Shore A hardness), and the insulating materials 230A, 230B have a Shore A hardness of about 52 (e.g., in the range of 50 to 55 Shore A hardness). In addition to the arrangement of insulating materials and the multilayering of the reinforcing layer 240, features of the aforementioned example can be incorporated into this specification. Therefore, for the sake of brevity, further explanation of this example is omitted / unnecessary.

[0060] The technologies of this disclosure described herein can be further understood in accordance with the following provisions.

[0061] Clause 1. A flexible circuit for an end effector of a medical probe, the flexible circuit comprising a flexible substrate layer extending along a longitudinal axis, the flexible substrate layer comprising a first side and a second side along a vertical axis perpendicular to the longitudinal axis, a plurality of tines extending along the longitudinal axis, a first zone including a portion of at least one of the plurality of tines, a second zone including another portion of the plurality of tines, a plurality of electrodes disposed on each of the plurality of tines of the flexible substrate layer, and a reinforcing layer disposed on the first side of the flexible substrate layer and in the first zone of the flexible circuit such that (i) the first thickness of the first zone of the flexible circuit, measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

[0062] Clause 2. The flexible circuit described in Clause 1, wherein multiple electrodes are arranged on a second zone of the flexible circuit.

[0063] Clause 3. The second zone is the flexible circuit described in Clause 1 or 2, extending from the first zone to the furthest end of the flexible circuit.

[0064] Clause 4. A flexible circuit as described in any one of Clauses 1 to 3, wherein the flexible circuit is asymmetrically rigid with respect to the longitudinal axis in the direction perpendicular to the flexible circuit.

[0065] Clause 5. The flexible circuit is asymmetrically rigid in the first zone, as described in Clause 4.

[0066] Clause 6. A flexible circuit according to any one of Clauses 1 to 5, wherein multiple electrodes are arranged on the first side of the flexible substrate layer.

[0067] Clause 7. A flexible circuit according to any one of Clauses 1 to 6, wherein the reinforcing layer terminates at the distal end of the first zone, and the multiple electrodes are located in the second zone.

[0068] Clause 8. A flexible circuit according to any one of Clauses 1 to 7, wherein the reinforcing layer comprises a transition section located proximal to the second zone, the transition section having either a stepped or tapered outer shape.

[0069] Clause 9. A flexible circuit according to any one of Clauses 1 to 9, comprising a base, wherein a plurality of tines include a first tine extending from the base along the longitudinal axis, a second tine extending from the base along the longitudinal axis, a third tine extending from the base along the longitudinal axis, a fourth tine extending from the base along the longitudinal axis, and a fifth tine extending from the base along the longitudinal axis.

[0070] Clause 10. The flexible circuit according to Clause 9, wherein the reinforcing layer is located on the base and the third tine.

[0071] Clause 11. The reinforcing layer is located on the base, the second tine, the third tine, and the fourth tine of the flexible circuit as described in Clause 9.

[0072] Clause 12. The flexible circuit as described in Clause 9, wherein the reinforcing layer is located on the base, the first tine, the second tine, the third tine, the fourth tine, and the fifth tine.

[0073] Clause 13. A flexible circuit as described in any one of Clauses 9 to 12, wherein the third tine is aligned with the longitudinal axis and the first, second, fourth, and fifth tines are offset from the longitudinal axis.

[0074] Clause 14. A flexible circuit as described in any one of Clauses 9 to 13, wherein two or more electrodes of a plurality of electrodes are arranged on each tine.

[0075] Clause 15. Each tine is a flexible circuit as described in any one of Clauses 9 to 14, extending within the first and second zones.

[0076] Clause 16. A flexible circuit as described in any one of Clauses 9 to 15, comprising a plurality of air gaps defined between tines.

[0077] Clause 17. A flexible circuit as described in any one of Clauses 1 to 16, wherein the first thickness is at least 50 percent greater than the second thickness.

[0078] Clause 18. A flexible circuit according to any one of Clauses 1 to 17, further comprising a coverlay disposed between a flexible substrate and a reinforcing layer, wherein the reinforcing layer is disposed on the coverlay.

[0079] Clause 19. The reinforcing layer includes an adhesive layer connecting the reinforcing layer to the coverlay, as described in Clause 18.

[0080] Clause 20. The reinforcing layer and flexible substrate layer form a monolithic structure, as described in any one of Clauses 1 to 17.

[0081] Clause 21. The reinforcing layer comprises a flexible biocompatible material layer having a Shore A hardness of approximately 62, as described in any one of Clauses 1 to 20.

[0082] Clause 22. A flexible circuit according to any one of Clauses 1 to 20, wherein the reinforcing layer comprises a first flexible biocompatible material layer and a second flexible biocompatible material layer laminated together.

[0083] Clause 23. The flexible circuit according to Clause 22, wherein the reinforcing layer includes a third flexible biocompatible material layer laminated on a first biocompatible material layer and a second biocompatible material layer.

[0084] Clause 24. A flexible circuit as described in any one of Clauses 1 to 23, wherein the reinforcing layer comprises polyimide.

[0085] Clause 25. An end effector for a medical probe, the end effector comprising: an insulating material; a framework disposed within the insulating material, the framework being substantially planar along a first longitudinal axis; and a first flexible circuit, disposed within the insulating material such that the first flexible circuit is spaced apart from the framework along a vertical axis perpendicular to the first longitudinal axis, the first flexible circuit comprising a first flexible substrate layer extending along a second longitudinal axis parallel to the first longitudinal axis, the first flexible substrate layer comprising a first side and a second side along a vertical axis perpendicular to the longitudinal axis. An end effector comprising: a first flexible circuit; a plurality of tines extending along a longitudinal axis; a first zone including a portion of at least one of the plurality of tines; a second zone including another portion of the plurality of tines; a plurality of electrodes disposed on each of the plurality of tines in the flexible substrate layer; and a reinforcing layer disposed on the first side of the flexible substrate layer and in the first zone of the flexible circuit such that (i) the first thickness of the first zone of the flexible circuit, measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

[0086] Clause 26. The first side of the first flexible substrate layer faces away from the framework, as described in Clause 25.

[0087] Clause 27. The end effector according to Clause 25 or 26, wherein the first reinforcing layer extends along the vertical axis away from the first flexible substrate layer and away from the framework.

[0088] Clause 28. The end effector according to any one of Clauses 25 to 27, further comprising a second flexible circuit disposed within an insulating material such that the second flexible circuit is spaced apart from the framework and the first flexible circuit along a vertical axis.

[0089] Clause 29. The end effector according to Clause 28, wherein the second flexible circuit comprises a second flexible substrate layer having a first side and a second side along a vertical axis, and a second reinforcing layer disposed on the first side of the second flexible substrate layer and within the first zone of the second flexible circuit such that (i) the first thickness of the first zone of the second flexible circuit, measured along the vertical axis, is greater than the second thickness of the second zone of the second flexible circuit, and (ii) the first bending stiffness of the first zone of the second flexible circuit is greater than the second bending stiffness of the second zone of the second flexible circuit.

[0090] Clause 30. The second reinforcing layer extends along the vertical axis away from the second flexible substrate layer, as described in Clause 29, to form the end effector.

[0091] Clause 31. An end effector for a medical probe, the end effector comprising: an insulating material; a framework disposed within the insulating material, which is substantially planar along a first longitudinal axis; and a first flexible circuit disposed within the insulating material, the first flexible circuit comprising a first flexible substrate layer extending along a second longitudinal axis parallel to the first longitudinal axis, which comprises a first side and a second side along a vertical axis perpendicular to the first longitudinal axis; a plurality of tines extending along the longitudinal axis; a first zone comprising a portion of at least one of the plurality of tines; and another portion of the plurality of tines. An end effector comprising: a first flexible circuit comprising a first flexible substrate layer comprising a second zone, a plurality of electrodes disposed in each of a plurality of tines of the flexible substrate layer, and a reinforcing layer disposed on the insulating material on the first side of the first flexible substrate layer and within the first zone of the flexible circuit, comprising a plurality of biocompatible material layers laminated together, such that (i) the first thickness of the first zone of the flexible circuit, measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

[0092] Clause 32. The end effector according to Clause 31, further comprising a second flexible circuit, wherein the insulating material comprises a first insulating sheet and a second insulating sheet, and the first and second insulating sheets are separated from the framework, respectively, by the first flexible circuit and the second flexible circuit along a vertical axis perpendicular to the vertical axis.

[0093] An insulating material such that the first flexible circuit is separated from the framework along a vertical axis perpendicular to the vertical axis.

[0094] Clause 33. A method for forming a flexible substrate layer of a flexible circuit, the flexible substrate layer comprising: a first surface located on a first side of the flexible substrate layer; a second surface located on a second side of the flexible substrate layer; a plurality of tines; a first zone comprising a portion of at least one of the plurality of tines; and a second zone comprising another portion of the plurality of tines; forming a plurality of electrodes on the first surface; and forming a reinforcing layer on the first side of the flexible substrate layer and within the first zone of the flexible circuit such that (i) the first thickness of the first zone of the flexible circuit, measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit; and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

[0095] Clause 34. The method of Clause 33, wherein forming electrodes on a first surface includes forming electrodes on a first surface within a second zone of a flexible substrate.

[0096] Clause 35. The method according to Clause 33 or 34, wherein forming a reinforcing layer on a first side of a flexible substrate layer includes adhering a flexible biocompatible material layer to the flexible substrate.

[0097] Clause 36. The method according to any one of Clauses 33 to 35, wherein forming a flexible substrate includes adhering a coverlay to a first surface of the flexible substrate.

[0098] Clause 37. The method according to Clause 36, wherein forming a reinforcing layer on a first side of a flexible substrate layer includes adhering the reinforcing layer to a coverlay.

[0099] Clause 38. The method according to Clause 33 or 34, wherein the steps of forming a flexible substrate layer and forming a reinforcing layer include the step of forming a flexible substrate and a reinforcing layer by molding a flexible biocompatible material.

[0100] The embodiments described above are cited as examples, and the technology of this disclosure is not limited to those specifically illustrated and described in the above specification. Rather, the scope of the technology of this disclosure includes both combinations and partial combinations of the various features described above, as well as variations and modifications thereof not disclosed in the prior art, which a person skilled in the art would conceive of by reading the above description.

[0101] [Implementation Method] (1) A flexible circuit for the end effector of a medical probe, wherein the flexible circuit is A flexible substrate layer extending along the longitudinal axis, wherein the flexible substrate layer is A first side and a second side along a vertical axis perpendicular to the longitudinal axis, Multiple tines extending along the longitudinal axis, A first zone comprising a portion of at least one of the plurality of tines, A flexible substrate layer comprising: a second zone including another portion of the plurality of tines; A plurality of electrodes arranged in each of the plurality of tines of the flexible substrate layer, A flexible circuit comprising: (i) a first thickness of the first zone of the flexible circuit, measured along the vertical axis, greater than the second thickness of the second zone of the flexible circuit; and (ii) a reinforcing layer disposed on the first side of the flexible substrate layer and in the first zone of the flexible circuit, such that the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone. (2) The flexible circuit according to Embodiment 1, wherein the plurality of electrodes are arranged on the second zone of the flexible circuit. (3) The flexible circuit according to Embodiment 1, wherein the second zone extends from the first zone to the most distal end of the flexible circuit. (4) The flexible circuit according to Embodiment 1, wherein the flexible circuit is rigid asymmetrically with respect to the longitudinal axis in the direction perpendicular to the flexible circuit. (5) The flexible circuit according to Embodiment 4, wherein the flexible circuit is asymmetrically rigid in the first zone.

[0102] (6) The flexible circuit according to Embodiment 1, wherein the plurality of electrodes are arranged on the first side of the flexible substrate layer. (7) The flexible circuit according to Embodiment 1, wherein the reinforcing layer terminates at the distal end of the first zone, and the plurality of electrodes are arranged in the second zone. (8) The flexible circuit according to Embodiment 1, wherein the reinforcing layer comprises a transition section located proximal to the second zone, and the transition section comprises one of a stepped or tapered outer shape. (9) The flexible substrate comprises a base, and the plurality of tines are A first tine extending from the base along the longitudinal axis, A second tine extending from the base along the longitudinal axis, A third tine extending from the base along the longitudinal axis, A fourth tine extending from the base along the longitudinal axis, The flexible circuit according to Embodiment 1, comprising a fifth tine extending from the base along the longitudinal axis. (10) The flexible circuit according to embodiment 9, wherein the reinforcing layer is disposed on the base and the third tine.

[0103] (11) The flexible circuit according to embodiment 9, wherein the reinforcing layer is disposed on the base, the second tine, the third tine, and the fourth tine. (12) The flexible circuit according to Embodiment 9, wherein the reinforcing layer is disposed on the base, the first tine, the second tine, the third tine, the fourth tine, and the fifth tine. (13) The flexible circuit according to Embodiment 9, wherein the third tine is aligned with the longitudinal axis, and the first tine, the second tine, the fourth tine, and the fifth tine are offset from the longitudinal axis. (14) The flexible circuit according to Embodiment 1, wherein the first thickness is at least 50 percent greater than the second thickness. (15) The flexible circuit according to Embodiment 1, further comprising a coverlay disposed between the flexible substrate and the reinforcing layer, wherein the reinforcing layer is disposed on the coverlay.

[0104] (16) An end effector for a medical probe, wherein the end effector is Insulating material, A framework disposed within the insulating material, the framework being substantially planar along the first longitudinal axis, A first flexible circuit, wherein the first flexible circuit is arranged in the insulating material such that it is spaced apart from the framework along a vertical axis perpendicular to the first longitudinal axis, A first flexible substrate layer extending along a second longitudinal axis parallel to the first longitudinal axis, A first side and a second side along a vertical axis perpendicular to the longitudinal axis, Multiple tines extending along the longitudinal axis, A first zone comprising a portion of at least one of the plurality of tines, A first flexible circuit comprising a flexible substrate layer, comprising a second zone including another portion of the plurality of tines, A plurality of electrodes arranged in each of the plurality of tines of the flexible substrate layer, An end effector comprising: (i) a reinforcing layer disposed on the first side of the flexible substrate layer and in the first zone of the flexible circuit such that (i) the first thickness of the first zone of the flexible circuit, as measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone. (17) The end effector according to embodiment 16, wherein the first side of the first flexible substrate layer faces away from the framework. (18) The end effector according to embodiment 16, wherein the first reinforcing layer extends along the vertical axis in a direction away from the first flexible substrate layer and away from the framework. (19) The end effector according to embodiment 16, further comprising a second flexible circuit disposed within the insulating material, wherein the second flexible circuit is spaced apart from the framework and the first flexible circuit along the vertical axis. (20) A method, The process involves forming a flexible substrate layer for a flexible circuit, wherein the flexible substrate layer is The first surface disposed on the first side of the flexible substrate layer, A second surface disposed on the second side of the flexible substrate layer, Multiple tines, A first zone comprising a portion of at least one of the plurality of tines, A second zone comprising another portion of the plurality of tines, Forming multiple electrodes on the surface of the above 1, A method comprising: (i) forming a reinforcing layer on the first side of the flexible substrate layer and within the first zone of the flexible circuit such that (i) the first thickness of the first zone of the flexible circuit, as measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

Claims

1. A flexible circuit for the end effector of a medical probe, wherein the flexible circuit is A flexible substrate layer extending along the longitudinal axis, wherein the flexible substrate layer is The first side and the second side along a vertical axis perpendicular to the longitudinal axis, Multiple tines extending along the longitudinal axis, A first zone including a portion of at least one of the plurality of tines, A flexible substrate layer comprising: a second zone including another portion of the plurality of tines; A plurality of electrodes arranged in each of the plurality of tines of the flexible substrate layer, A flexible circuit comprising: (i) a first thickness of the first zone of the flexible circuit, measured along the vertical axis, greater than the second thickness of the second zone of the flexible circuit; and (ii) a reinforcing layer disposed on the first side of the flexible substrate layer and in the first zone of the flexible circuit, such that the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

2. The flexible circuit according to claim 1, wherein the plurality of electrodes are arranged on the second zone of the flexible circuit.

3. The flexible circuit according to claim 1, wherein the second zone extends from the first zone to the most distal end of the flexible circuit.

4. The flexible circuit according to claim 1, wherein the flexible circuit is rigid asymmetrically with respect to the longitudinal axis in the direction perpendicular to the flexible circuit.

5. The flexible circuit according to claim 4, wherein the flexible circuit is asymmetrically rigid in the first zone.

6. The flexible circuit according to claim 1, wherein the plurality of electrodes are arranged on the first side of the flexible substrate layer.

7. The flexible circuit according to claim 1, wherein the reinforcing layer terminates at the distal end of the first zone, and the plurality of electrodes are arranged in the second zone.

8. The flexible circuit according to claim 1, wherein the reinforcing layer comprises a transition section located proximal to the second zone, and the transition section comprises one of a stepped or tapered outer shape.

9. The flexible substrate comprises a base, and the plurality of tines are A first tine extending from the base along the longitudinal axis, A second tine extending from the base along the longitudinal axis, A third tine extending from the base along the longitudinal axis, A fourth tine extending from the base along the longitudinal axis, The flexible circuit according to claim 1, further comprising: a fifth tine extending from the base along the longitudinal axis.

10. The flexible circuit according to claim 9, wherein the reinforcing layer is disposed on the base and the third tine.

11. The flexible circuit according to claim 9, wherein the reinforcing layer is disposed on the base, the second tine, the third tine, and the fourth tine.

12. The flexible circuit according to claim 9, wherein the reinforcing layer is disposed on the base, the first tine, the second tine, the third tine, the fourth tine, and the fifth tine.

13. The flexible circuit according to claim 9, wherein the third tine is aligned with the longitudinal axis, and the first tine, the second tine, the fourth tine, and the fifth tine are offset from the longitudinal axis.

14. The flexible circuit according to claim 1, wherein the first thickness is at least 50 percent greater than the second thickness.

15. The flexible circuit according to claim 1, further comprising a coverlay disposed between the flexible substrate and the reinforcing layer, wherein the reinforcing layer is disposed on the coverlay.

16. An end effector for a medical probe, wherein the end effector is Insulating material, A framework disposed within the insulating material, the framework being substantially planar along the first longitudinal axis, A first flexible circuit, wherein the first flexible circuit is arranged in the insulating material such that it is spaced apart from the framework along a vertical axis perpendicular to the first longitudinal axis, A first flexible substrate layer extending along a second longitudinal axis parallel to the first longitudinal axis, The first side and the second side along a vertical axis perpendicular to the longitudinal axis, Multiple tines extending along the longitudinal axis, A first zone including a portion of at least one of the plurality of tines, A first flexible circuit comprising a flexible substrate layer, comprising a second zone including another portion of the plurality of tines, A plurality of electrodes arranged in each of the plurality of tines of the flexible substrate layer, An end effector comprising: (i) a reinforcing layer disposed on the first side of the flexible substrate layer and in the first zone of the flexible circuit such that the first thickness of the first zone of the flexible circuit, as measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

17. The end effector according to claim 16, wherein the first side of the first flexible substrate layer faces away from the framework.

18. The end effector according to claim 16, wherein the first reinforcing layer extends along the vertical axis in a direction away from the first flexible substrate layer and away from the framework.

19. The end effector according to claim 16, further comprising a second flexible circuit disposed within the insulating material, wherein the second flexible circuit is spaced apart from the framework and the first flexible circuit along the vertical axis.

20. It is a method, The process involves forming a flexible substrate layer for a flexible circuit, wherein the flexible substrate layer is The first surface disposed on the first side of the flexible substrate layer, The second surface disposed on the second side of the flexible substrate layer, Multiple tines, A first zone including a portion of at least one of the plurality of tines, A second zone comprising another portion of the plurality of tines, Forming a plurality of electrodes on the first surface, A method comprising: (i) forming a reinforcing layer on the first side of the flexible substrate layer and within the first zone of the flexible circuit such that (i) the first thickness of the first zone of the flexible circuit, as measured along the vertical axis, is greater than the second thickness of the second zone of the flexible circuit, and (ii) the first bending stiffness of the first zone is greater than the second bending stiffness of the second zone.

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