Reinforced flexible circuit for end effectors of medical catheters

Abstract

To ensure that the flexible circuit used in the end effector of the catheter can be bent sufficiently without damage. [Solution] The technology of the present disclosure includes an end effector comprising at least one flexible circuit extending along a longitudinal axis, having a substrate supporting at least one electrical trace and at least one electrode. A portion of the substrate may be reinforced by forming an electrical trace having a plurality of bends and / or by providing a plurality of bends in the substrate. Furthermore, a portion of the substrate may include a plurality of layers, each having an electrical trace offset from one another.

Description

[Technical Field]

[0001] The present invention generally relates to minimally invasive medical devices, specifically sensing catheters, and more particularly to cardiac mapping catheters and their manufacture, but is not exclusive. [Background technology]

[0002] Cardiac arrhythmias, such as atrial fibrillation, occur when electrical signals are abnormally conducted from areas of cardiac tissue to adjacent tissues, disrupting the normal cardiac cycle and causing asynchronous rhythms. Unwanted signal sources may be located in the atria or ventricles. Unwanted signals can be conducted through cardiac tissue to other parts of the body, causing or perpetuating arrhythmias.

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

[0004] In this two-step procedure, which includes mapping and subsequent ablation, a catheter equipped with one or more electrical sensors is typically advanced into the heart, and electrical activity at each point within the heart is sensed and measured by acquiring data at multiple points. This data is then used to select the target area where ablation will be performed.

[0005] Such catheters are desirable to be bendable to allow sufficient electrode contact with various tissue surfaces, such as flat, curved, irregular, or non-planar surface tissues, and to be foldable for non-invasive advancement and retreat through the patient's vascular system. As is understood, the flexible circuits used in ablation catheters are often limited in the amount of bending they can take without breaking. [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, it is desirable to develop new methods to ensure that the flexible circuit used in the end effector of a catheter can be bent sufficiently without damage. These and other advantages are disclosed herein. [Means for solving the problem]

[0007] The present disclosure provides a flexible circuit for an end effector of a medical probe. The end effector may extend along a longitudinal axis. The flexible circuit may include a first substrate supporting a first electrical trace extending along a portion of the end effector. The first electrical trace may include a plurality of bends such that the first electrical trace defines a meandering shape. A second substrate may be provided and may be laminated with the first substrate in the thickness direction. The second substrate may support a second electrical trace extending along a portion of the end effector, along which the first electrical trace also extends. The second electrical trace may also include a plurality of bends such that the second electrical trace also defines a meandering shape. The second electrical trace may be offset from the first electrical trace at one or more of the plurality of bends.

[0008] The technology of this disclosure may include an end effector comprising a flexible circuit having a plurality of electrodes. The flexible circuit may be disposed within a first insulating layer of an insulating material, and each of the plurality of electrodes may include a contact surface. The insulating material may be continuous with the contact surfaces such that only at least some of the contact surfaces of the plurality of electrodes are exposed to the ambient environment. The framework may be at least partially enclosed within the first insulating layer, and the lumen may be defined within the insulating material.

[0009] The technology of this disclosure may include a medical probe including an end effector. The end effector may extend along the longitudinal direction and include a flexible circuit. The flexible circuit may include a substrate supporting an electrical trace, the electrical trace extending along a portion of the end effector. The substrate of the flexible circuit may have a plurality of bends such that the substrate defines a meandering shape. The plurality of bends of the substrate may be offset by an offset angle with respect to the longitudinal axis. The electrical trace may be spaced a predetermined distance from the inner radius of each bend.

[0010] The technology of this disclosure may include a medical probe including an end effector. The end effector may include a flexible circuit extending along its longitudinal direction. The flexible circuit may include a substrate, the substrate having a proximal portion extending distally from the proximal end of the flexible circuit toward a first set of electrodes among a plurality of electrodes. The substrate may support a first electrical trace, the first electrical trace having a plurality of bends such that the electrical trace has a meandering shape. An intermediate portion of the substrate extending between the first set of electrodes and a second set of electrodes may include a plurality of bends such that the substrate defines a meandering shape in the intermediate portion. The bends may be offset with respect to the longitudinal axis by an offset angle.

[0011] Additional features, functions, and applications of the technology disclosed herein are discussed in more detail herein. [Brief explanation of the drawing]

[0012] This patent or application document includes at least one drawing made in color. A copy of this patent or patent application publication containing a color drawing will be provided by the Patent Office upon request and payment of the required fee. [Figure 1] This is a schematic diagram of a medical system, including a medical device, based on the technology disclosed herein. [Figure 2] This is a schematic diagram of a perspective view of an end effector using the technology disclosed herein. [Figure 3] This is a schematic diagram of an exploded perspective view of the end effector shown in Figure 2, based on the technology of this disclosure. [Figure 4] This is a schematic diagram of a flexible circuit for an end effector based on the technology disclosed herein. [Figure 5] This is a schematic diagram of a substrate for a flexible circuit of an end effector, on which one or more electrical traces are provided, according to the technology of the present disclosure. [Figure 6A] This is a schematic diagram of the distal angle portion of the flexible circuit of an end effector according to the technology disclosed herein. [Figure 6B] This is a schematic diagram of the first substrate of the flexible circuit at the distal angle of the end effector of the technology disclosed herein. [Figure 6C] This is a schematic diagram of a detailed view of Figure 6B, showing the first substrate at the distal angle of the flexible circuit of the end effector according to the technology of the present disclosure. [Figure 6D] This is a schematic diagram of the second substrate of the flexible circuit at the distal angle of the end effector according to the technology of the present disclosure. [Figure 6E] This is a schematic diagram of a detailed view of Figure 6D showing a second substrate of the flexible circuit at the distal angle of the end effector according to the technology of the present disclosure. [Figure 7] This is a schematic diagram of a detailed view of the intermediate portion of the flexible circuit of an end effector according to the technology disclosed herein. [Figure 8A] This invention provides a visualization of finite element analysis showing strain concentration on a substrate of a flexible circuit of an end effector under tension, using the technology described herein. [Figure 8B]Visualization of a finite element analysis showing strain concentration on a substrate of a flexible circuit of an end effector under tension, according to the technology of the present disclosure. [Figure 8C] Visualization of a finite element analysis showing strain concentration on a substrate of a flexible circuit of an end effector under tension, according to the technology of the present disclosure. [Figure 8D] Visualization of a finite element analysis showing strain concentration on a substrate of a flexible circuit of an end effector under tension, according to the technology related to the present disclosure. [Figure 8E] Visualization of a finite element analysis showing strain concentration on a substrate of a flexible circuit of an end effector under tension, according to the technology related to the present disclosure. [Figure 8F] Graphical display showing strain and rigidity of a substrate of a flexible circuit of an end effector under tension in various configurations, according to the technology of the present disclosure. [Figure 9] Schematic drawing of a detailed view of a proximal portion of a flexible circuit of an end effector, according to the technology of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0013] The following detailed description should be read with reference to the drawings, and like elements in different drawings are numbered the same. 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, not limiting, and exemplifies the principles of the invention. This specification enables those skilled in the art to make and use the invention and describes some embodiments, adaptations, variations, alternatives, and uses of the invention, including what is currently considered to be the best mode for carrying out the invention.

[0014] Where used herein, the terms “about” or “approximately” for any number or range indicate a preferred dimensional tolerance that enables some or all of the components to function for the intended purposes described herein. More specifically, “about” or “approximately” may refer to a range of values ​​within ±20% of the enumerated values, while “about 90%” may refer to a range of values ​​between 71% and 110%. 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 present invention 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.

[0015] In the context of this specification, the tissues, vascular systems, or organs of “patient,” “host,” “user,” and “subject” may be those of a human or any animal. It should be understood that animals can be any applicable type, including but not limited to mammals, veterinary animals, domestic animals, or pet animals. For example, an animal may be a laboratory animal specifically selected to possess certain characteristics similar to humans (e.g., rats, dogs, pigs, monkeys, etc.). It should be understood that a subject can be, for example, any applicable human patient.

[0016] As discussed herein, “physician” may include physicians, surgeons, technicians, scientists, operators, or any other individuals or delivery devices involved in the delivery of a multi-electrode medical device for the treatment of drug-refractory atrial fibrillation to a subject.

[0017] As discussed herein, the terms “to ablate” or “ablation” refer to the devices and corresponding systems of this disclosure and to components and structural features configured to reduce or prevent the generation of irregular cardiac signals within cells. Throughout this disclosure, these terms are interchangeable with pulsed electric field (PEF) and pulsed field ablation (PFA), for example, by utilizing thermal energy such as radio frequency (RF) ablation or non-thermal energy such as irreversible electroporation (IRE). In relation to the devices and corresponding systems of this disclosure, “to ablate” or “ablation” is used throughout this disclosure to refer to thermal or non-thermal ablation of cardiac tissue in specific conditions, including but not limited to arrhythmias, atrial flutter ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The terms “to ablate” or “ablation” also include known methods, devices, and systems for achieving various forms of body tissue ablation, as understood by those skilled in the art.

[0018] As discussed herein, the terms “tubular” and “tube” are to be interpreted broadly and are not limited to a right cylindrical structure, a structure with a strictly circular cross-section, or a structure with a uniform cross-section over its entire length. For example, a tubular structure is generally illustrated as a substantially right cylindrical structure. However, a tubular structure may have a tapered or curved outer surface without departing from the scope of this disclosure.

[0019] This disclosure relates to systems, methods, or uses and devices for mapping and ablation of cardiac tissue for the treatment of cardiac arrhythmias. Ablation energy is typically delivered to cardiac tissue by the tip of a medical device (e.g., a medical probe or catheter) that can deliver the ablation energy along with the tissue being ablated. Some exemplary catheters include a three-dimensional structure in their tip 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.

[0020] 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.

[0021] 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.

[0022] 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 patient's vascular system 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 14 configured to sense IEGM is illustrated herein. To sense a target site in the heart 12, the physician 24 brings the catheter shaft (i.e., multilayer end effector 100) with the distal tip 28 of the catheter 14 into contact with the heart wall. For ablation, the physician 24 similarly brings the distal end of the ablation catheter to the target site for ablation.

[0023] Catheter 14 is an exemplary catheter comprising one, preferably more electrodes, optionally distributed across an end effector 100 coupled to a catheter shaft and configured to sense IEGM signals, as will be described in more detail below. Catheter 14 may additionally include a position sensor embedded in or near the end effector 100 to track the position and orientation of the end effector 100. Optionally and preferably, the position sensor is a magnetic-based position sensor comprising multiple magnetic coils for sensing three-dimensional (3D) position and orientation.

[0024] A magnetic-based position sensor may operate in conjunction with a position pad 25 which includes a plurality of magnetic coils 32 configured to generate a magnetic field within a given 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 position pad 25 and sensed by the magnetic-based position sensor. Details of magnetic-based position sensing technology are described in U.S. Patents No. 5,391,199, No. 5,443,489, No. 5,558,091, No. 6,172,499, No. 6,239,724, No. 6,332,089, No. 6,484,118, No. 6,618,612, No. 6,690,963, No. 6,788,967, and No. 6,892,091, each of which is incorporated herein by reference.

[0025] System 10 includes one or more electrode patches 38 placed for skin contact on a patient 23 to establish a position reference for the position pad 25 and impedance-based tracking of the electrodes. For impedance-based tracking, current is directed to the electrodes 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.

[0026] The recorder 11 displays the electromagnetism 21 captured by the surface ECG electrodes 18 and the intracardiac electromagnetism (IEGM) captured by the electrodes 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.

[0027] System 10 may include an ablation energy generator 50 adapted to transmit ablation energy from one or more electrodes located at the distal tip 28 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.

[0028] 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.

[0029] 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 (5) displaying areas of interest, such as the locations where ablation energy has been applied, on the display device 27. 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.

[0030] Figure 2 shows an example of an end effector 100 according to the present disclosure to achieve ease of manufacture, cost reduction, and enhancement of end effector characteristics such as desired foldability, operability, robustness, rigidity, mapping resolution, electrode contact with the target anatomical structure, and the suitability of the end effector 100 disclosed herein to flat, curved, irregular, and / or non-planar tissue surfaces found within the target anatomical structure. The end effector 100 may extend along the longitudinal axis LL from the proximal end to the distal end, with the width extending perpendicular to the longitudinal axis and the thickness extending perpendicular to the longitudinal and horizontal axes.

[0031] The end effector 100 may include a flexible circuit 110 containing multiple electrodes. As used herein, 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 (e.g., Panasonic FELIOS® series of flexible circuit boards), nitinol substrates, or polymer substrates such as Panasonic BEYOLEX® PRINTED ELECTRONICS SUBSTRATE series. In some embodiments, the flexible circuit layers described herein can be fabricated primarily from polyimide. In other embodiments, they can be fabricated using biocompatible polyimide, glass-reinforced epoxy laminates, copper, or graphene, either alone or in combination. The first flexible circuit 110 and the second flexible circuit 140 may include conductive traces formed directly on a polymer substrate, with electrodes having substantially much thicker versions of the traces, such that a typical polyimide substrate is no longer required. In some embodiments, the electrodes described herein may include at least one mapping electrode and / or at least one ablation electrode, and may be configured to detect an electrophysiological signal or to transmit ablation energy AC or DC from an energy generator to the tissue according to various ablation methods mentioned herein, such as RF, IRE, etc.

[0032] The flexible circuit 110 can be placed on an insulating material 120 (also known as an insulating material). The insulating material 120 can be continuous with the contact surfaces of the electrodes such that only the contact surfaces of at least some of the electrodes 112 are exposed to the surrounding environment. As used herein, the term “contact surface” includes portions of the electrode having a substantially flat surface and one or more edges directly surrounding the flat surface. The electrodes 112 may have slightly rounded, rounded, or chamfered edges that contact the tissue along with the substantially flat surface when the end effector 100 is placed in contact with the tissue. As used herein, “surrounding environment” refers to the external environment, such as an operating room, before the end effector 100 is placed in the organ or biological organ.

[0033] It should be noted that all electrodes 112 on the end effector 100 described herein do not need to be exposed through the insulating material 120, as these unexposed electrodes may 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 offset against the entire end effector having a reference electrode that does not come into contact with tissue and only with blood. Irrigation can be provided using irrigation ports 163a on one side and 162b on the other side, which are in fluid communication with an irrigation line (not shown) located within the catheter shaft 210. Instead of a separate irrigation line from the catheter shaft 210, a lumen can be formed by extrusion molding of the catheter shaft 210 to provide a lumen channel. It should be noted that the port 163a or 162b may be configured to have sufficient flow-shattering properties so that the irrigation fluid covers the mapping electrode in the irrigation flow to prevent or reduce thrombus formation.

[0034] The end effector 100 may further include a framework 130 that is continuous with or at least partially enclosed within the insulating material 120. In an example where the end effector 100 includes a framework 130, the framework 130 may be separated from the flexible circuit 110 by a portion of the insulating material 120 that lies between them.

[0035] Figure 3 shows an exploded view of the end effector 100, where its components are vertically separated along the vertical axis VV (also referred to as the height direction) of the end effector 100. The flexible circuit 110 may be a first flexible circuit 110, and the multiple electrodes 112 may be multiple first electrodes 112. The end effector 100 may further include a second flexible circuit 140 having multiple second electrodes 142. The second flexible circuit 140 may be spaced apart from the first flexible circuit 110. Furthermore, each flexible circuit 110, 140 may include its respective tine extending along the longitudinal axis LL, the tine supporting its respective electrode.

[0036] In examples having a first flexible circuit 110 and a second flexible circuit 140, the insulating material 120 may be placed between the first flexible circuit 110 and the second flexible circuit 140. In some embodiments, the insulating material 120 may be continuous with the contact surfaces of the electrodes such that only the contact surfaces of each second electrode are exposed to the ambient environment.

[0037] Electrodes 112 and 142 can sense electrophysiological signals or transmit ablation energy from an energy generator to tissue. In some embodiments, there are approximately 92 electrodes. In some embodiments, there are approximately 48 electrodes. In some embodiments, there are approximately 64 electrodes. In some embodiments, there are approximately 72 electrodes. In some embodiments, there are approximately 98 electrodes. However, those skilled in the art will understand that various numbers of electrodes 112 and 142 can be used without departing from the spirit and scope of this disclosure.

[0038] In the examples herein, the end effector 100 includes a framework 130 positioned between a first flexible circuit 110 and a second flexible circuit 140. The framework 130 may be a component of the end effector 100 that is separated from and distinct from the first flexible circuit 110, and positioned in close proximity to the first flexible circuit 110. In this case, insulating material 120 may be further positioned between the framework 130 and the second flexible circuit 140. The framework 130 may be formed from a planar or cylindrical stock of material using any preferred method. For example, the framework 130 may be formed by cutting, laser cutting, stamping, etc.

[0039] The framework includes multiple spines extending along the longitudinal axis LL. The tines of the flexible circuits 110, 140 may be approximately aligned with one or more of the spines, so that the spine 132 provides support to them.

[0040] The insulating material 120 may include a first insulating material sheet and a second insulating material sheet, which are fused together in close proximity to the framework 130 to form a single, continuous, generally planar insulating material 120. This insulating material 120 also works to enhance the non-traumatic properties of the end effector 100 and to protect the object from sharp edges.

[0041] Referring to Figure 4, the flexible circuit 110 of the end effector is shown extending along the longitudinal axis LL. As described above, the end effector may comprise a first flexible circuit 110 and a second flexible circuit. For brevity, a single flexible circuit may be referred to as flexible circuit 110 in this specification, but it should be understood that the embodiments and features of the flexible circuits discussed below may apply to both the first and second flexible circuits, as well as to further flexible circuits of the end effector.

[0042] In some embodiments, referring to Figure 4, the flexible circuit may extend along the longitudinal axis from a proximal end 102 to a distal end 104. The flexible circuit 110 may comprise a substrate 111 configured to support one or more electrodes. In some embodiments, the flexible circuit comprises one or more rows or sets of electrodes arranged along the longitudinal axis. Electrical traces (not shown in Figure 4) may connect the electrodes to and / or to the proximal end 102 of the flexible circuit.

[0043] In some embodiments, as shown in Figure 4, the flexible circuit 110 may include a proximal portion 152 extending between the proximal end 102 of the flexible circuit and the first set of electrodes 112a. In some embodiments, the flexible circuit 110 may include an intermediate portion 154 extending between the first set of electrodes 112a and the third set of electrodes 112c, and may include a second set of electrodes 112b. A fourth set of electrodes 112d may be provided at the distal end 104 of the flexible circuit. In some embodiments, the first set of electrodes 112a, the second set of electrodes 112b, and the third set of electrodes 112c each include an equal number of electrode pairs. For example, as shown in Figure 4, the first, second, and third sets of electrodes 112a, 112b, and 112c each include five electrode pairs or ten individual electrodes. In some embodiments, the fourth set of electrodes 112d includes fewer electrodes than the first, second, and third sets of electrodes 112a, 112b, and 112c. For example, as shown in Figure 4, the fourth set of electrodes 112d may comprise only three pairs of electrodes. The distal angle 156 of the flexible circuit 110 may comprise a curved portion of the substrate 111 extending from the outermost electrode pair of the third set of electrodes 112c to the outermost electrode pair of the fourth set of electrodes 112d.

[0044] Referring to Figure 5, a portion of the flexible circuit 110 of the end effector is shown extending along the longitudinal axis LL. In some embodiments, the substrate 111 includes a plurality of bends 118 such that the substrate 111 has a meandering shape. In some embodiments, the substrate supports one or more electrical traces 114. In some embodiments, as shown in Figure 5, the electrical trace includes a plurality of bends 118b such that the electrical trace 114 follows the curvature of the substrate 111 and forms a meandering shape. In some embodiments, each bend 118 is substantially U-shaped such that the substrate and the electrical trace 114 formed thereon bend 180° through the bend.

[0045] Referring to Figures 6A to 6E, the flexible circuit 110 comprises a first substrate 111a and a second substrate 111b laminated with the first substrate 111a to a certain thickness along at least a portion of the flexible circuit. In some embodiments, at least one first electrical trace 114a is provided on the first substrate 111a and at least one second electrical trace 114b is provided on the second substrate 111b. In some embodiments, the second electrical trace 114b is offset from the first electrical trace 114a to provide reinforcement to a portion of the flexible circuit.

[0046] Figure 6A shows the distal corner 156 of a flexible circuit in which the first substrate is laminated on the second substrate so that the first electrical trace 114a and the second electrical trace 114b are provided between the electrodes 112. Figure 6B shows only the first substrate 111a on which the first electrical trace 114a is provided. Figure 6C shows the distance D between the innermost edge of the first substrate 111a and the innermost edge of the first electrical trace 114a. a Figure 6D is a detailed view of Figure 6C. Figure 6D shows only the second substrate 111b on which the second electrical trace 114b is mounted. Figure 6F shows the distance D between the innermost edge of the second substrate 111b and the innermost edge of the second electrical trace 114b. b This is a detailed view of Figure 6D.

[0047] In some embodiments, the first electrical trace 114a has multiple bends such that the first electrical trace 114a forms a meandering shape. The second electrical trace 114b may also have multiple bends such that the second electrical trace 114b defines a meandering shape. The second electrical trace 114b and the first electrical trace 114a may each have a meandering shape with multiple bends, offset from each other, to provide reinforcement to a portion of the flexible circuit.

[0048] In some embodiments, the distal corner portion 156 of the flexible circuit can be reinforced by utilizing a layered substrate configuration with offset electrical traces. However, it will be understood that such a layered configuration with offset electrical traces may be applied to other areas of the flexible circuit.

[0049] In some embodiments, the width of the first substrate 111a is equal to the width of the second substrate 111b along a portion of the flexible circuit having a layered substrate configuration. In some embodiments, the first electrical trace 114a is located at a first distance D from the edge of the first substrate 111a. a The second electrical trace 114b is positioned at a second distance D from the corresponding edge of the second substrate 111b. b It is positioned as follows. In some embodiments, the distance D from the edge of the first substrate 111a to the edge of the first electrical trace 114a is a This is the second distance D from the edge of the second substrate to the edge of the second electrical trace 114b. b If the distance D is smaller or larger than the first substrate 111a and the second substrate 111b, the first electrical trace 114a and the second electrical trace 114b will be offset from each other when the first substrate 111a and the second substrate 111b are aligned and stacked. In some embodiments, the distance D from the edge of the first substrate 111a to the edge of the first electrical trace 114a is smaller or larger than the first electrical trace 114b. a The distance is equal to the width of the first electrical trace 114a or the second electrical trace 114b, and the distance D is equal to that distance. bsmaller or larger than. For example, the widths of the first electrical trace 114a and the second electrical trace 114b are 25 microns, and the first electrical trace 114a is at a distance D of 75 microns from the edge of the first substrate a If it is disposed at, the second electrical trace 114b may be disposed at a distance D of 50 microns from the edge of the second substrate b thereof.

[0050] In some embodiments, the electrode 112 is formed on the first substrate 111a. In some embodiments, the electrode 112 is formed on the second substrate. The first electrical trace 114a and the second electrical trace 1114b extend between adjacent electrodes and can connect the adjacent electrodes to each other. By providing two sets of electrical traces, the electrical connection can be maintained even if one of the electrical traces fails or is damaged.

[0051] FIG. 7 shows a portion of an intermediate portion 154 of a flexible circuit in which two electrodes aligned along or parallel to the longitudinal axis L-L are connected by a plurality of electrical traces 114a, 114b provided on a substrate 111. As described above, the substrate 111 can be a multilayer substrate having a first set of electrical traces 114a disposed on a first substrate and a second set of electrical traces 114b disposed on a second substrate.

[0052] In some embodiments, the substrate 111 includes a plurality of bending portions 118. In some embodiments, each bending portion 118 is substantially U-shaped such that the substrate and the electrical trace 114 formed thereon bend 180° through the bending portion. In some embodiments, as shown in FIG. 7, the electrical trace 114 also forms a meandering shape following the curvature of the substrate 111. In some embodiments, a portion of the substrate 111 provided between two electrodes 112 within the intermediate portion 154 of the flexible circuit includes two bending portions 118.

[0053] In some embodiments, the electrical traces 114 are positioned at a predetermined distance D between the inner radii R of each bend 118. In some embodiments, the predetermined distance D is measured between the innermost edge of the substrate 111 at the inner radius R of each bend 118 and the innermost electrical trace 114 closest to that innermost edge. In some embodiments, when the substrate 111 is bent, stress and strain are concentrated at the inner radius of each bend 118. By offsetting the innermost electrical traces 114 by a distance D from the inner radius of the substrate 111, the electrical traces 114 are subjected to less stress / strain. In some embodiments, the predetermined distance D is measured between the innermost electrical trace 114 and the radius R t It is more than three times that. For example, the innermost electrical trace 114 has a radius R of 0.5 mm. t If present, the innermost electrical trace 114 should be positioned at least 1.5 mm away from the inner radius R of each bend.

[0054] In some embodiments, each bend 118 of the substrate 111 includes a radius of curvature R. The radius of curvature R can be measured at the innermost curve of the substrate 111 in each bend 118. In some embodiments, the inner radius R of each bend 118 is at least about 0.01 millimeters. In some embodiments, the inner radius R of each bend 118 is at least about 0.03 millimeters. In some embodiments, the inner radius R of each bend 118 is about 0.03 mm to about 0.07 mm.

[0055] In some embodiments, as shown in Figure 7, the bent portion 118 is angle

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[0060] In some embodiments, the offset angle

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[0063] In some embodiments, the offset angle

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[0066] Figure 8A shows an offset angle of 35 degrees.

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[0068] Figure 8B shows an offset angle of 2 degrees.

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[0070] Figure 8C shows an offset angle of -3 degrees.

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[0072] Figure 8D shows an offset angle of 20 degrees.

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[0074] Figure 8E shows an offset angle of 10 degrees.

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[0076] Figure 8F is a graph showing the stiffness and strain values ​​for each exemplary configuration in Figures 8A to 8E. In some embodiments, the offset angle is approximately 10 to 20 degrees.

[0077]

number

[0078] Figure 9 shows a proximal portion 152 of a flexible circuit that extends distally from the proximal end of the flexible circuit toward a first set of electrodes among a plurality of electrodes (for example, a proximal portion 152 extending from the proximal end 102 of a flexible circuit 110 toward a first set of electrodes 112a among a plurality of electrodes 112, as shown in Figure 4). In some embodiments, the substrate 111 at the proximal end 152 of the flexible circuit supports a plurality of electrical traces 114. Each electrical trace 114 may include a plurality of bends, such that each electrical trace 114 includes a meandering shape. The meandering shape may be used to further reinforce the proximal end 152 of the flexible circuit. The meandering shape may be used to provide additional bends to the proximal end 152 of the flexible circuit.

[0079] In some embodiments, the proximal portion 152 of the substrate 111 comprises at least three arms 153 extending from the proximal end of the flexible circuit to a first set of electrodes. In some embodiments, the central arm 153a of the at least three arms 153 supports at least six electrical traces 114, and each outer arm 153b of the at least three arms 153 supports half the number of electrical traces 114 of the central arm 153a. In some embodiments, the electrical traces have a meandering shape near the proximal end of the flexible circuit and straighten out at the distal end 155 of the proximal portion 152 of the substrate 111 before reaching the first set of electrodes.

[0080] The technologies of this disclosure described herein can be further understood in accordance with the following provisions.

[0081] Clause 1: A flexible circuit for the end effector of a medical probe, the end effector extending along a longitudinal axis, the flexible circuit comprising: a first substrate supporting a first electrical trace extending along a portion of the end effector, the first electrical trace having a plurality of bends such that the first electrical trace defines a meandering shape; and a second substrate laminated with the first substrate in the thickness direction and supporting a second electrical trace extending along a portion of the end effector, the second electrical trace having a plurality of bends such that the second electrical trace defines a meandering shape, the second electrical trace being offset from the first electrical trace at one or more of the plurality of bends.

[0082] Clause 2: The flexible circuit described in Clause 1, wherein the first board has a width equal to the width of the second board along a portion of the end effector.

[0083] Clause 3: The flexible circuit as described in Clause 2, wherein the first electrical trace is located at a first distance from the edge of the first substrate, and the second electrical trace is located at a second distance from the corresponding edge of the second substrate, and the first distance is either less than or greater than the second distance.

[0084] Clause 4: A flexible circuit as described in any one of Clauses 1 to 3, wherein the second electrical trace is offset from the first electrical trace at the distal angle of the flexible circuit.

[0085] Clause 5: The first substrate is a flexible circuit as described in any one of Clauses 1 to 4, comprising at least two electrodes.

[0086] Clause 6: The flexible circuit according to Clause 5, wherein the first electrical trace extends between at least two electrodes and connects at least two electrodes to each other.

[0087] Clause 7: The flexible circuit according to Clause 6, wherein the second electrical trace extends between at least two electrodes and connects at least two electrodes to each other.

[0088] Clause 8: Flexible circuit for the end effector of a medical probe, wherein the end effector extends along a longitudinal axis, and the flexible circuit comprises a substrate supporting an electrical trace extending along a portion of the end effector, the substrate comprising a plurality of bends to define a meandering shape, the plurality of bends of the substrate being offset by an offset angle with respect to the longitudinal axis, and the electrical trace being spaced a predetermined distance from the inner radius of each bend.

[0089] Clause 9: The offset angle is approximately 10 to 35 degrees, as specified in Clause 8 for the flexible circuit.

[0090] Clause 10: The offset angle is approximately 10 to 20 degrees, as specified in Clause 8 for the flexible circuit.

[0091] Clause 11: A flexible circuit as described in any one of Clauses 8 to 10, wherein the multiple bends include two bends along a portion of the end effector extending between two electrodes.

[0092] Clause 12: The flexible circuit as described in Clause 11, wherein two bends are provided between electrodes in the intermediate portion of the flexible circuit.

[0093] Clause 13: A flexible circuit as described in any one of Clauses 8 to 12, wherein the inner radius of each bend is at least about 0.03 millimeters.

[0094] Clause 14: The inner radius of each bend is approximately 0.03 mm to approximately 0.07 mm, as described in any one of Clauses 8 to 13.

[0095] Clause 15: A flexible circuit according to any one of Clauses 8 to 14, wherein the flexible circuit comprises multiple electrical traces, and a predetermined distance is measured between the innermost edge of the substrate at the inner radius of each bend and the innermost electrical trace closest to said innermost edge.

[0096] Clause 16: The flexible circuit according to claim 15, wherein a predetermined distance between the inner radius of each bend and the innermost electrical trace is at least three times the radius of the innermost electrical trace at each bend.

[0097] Clause 17: Flexible circuit for an end effector of a medical probe, the end effector extending along a longitudinal axis, the flexible circuit comprising a substrate having a proximal portion extending distally from the proximal end of the flexible circuit toward a first set of electrodes of a plurality of electrodes, the substrate configured to support a first electrical trace, the first electrical trace comprising a plurality of bends such that the electrical trace has a meandering shape, the substrate comprising an intermediate portion extending between a first set of electrodes and a second set of electrodes, the substrate comprising a plurality of bends such that the intermediate portion defines a meandering shape, the bends being offset by an offset angle with respect to the longitudinal axis.

[0098] Clause 18: The flexible circuit as described in Clause 17, wherein the proximal portion of the substrate comprises at least three arms extending from the proximal end of the flexible circuit to a first set of electrodes, each arm supporting a plurality of electrical traces.

[0099] Clause 19: The flexible circuit described in Clause 18, wherein the central arm of at least three arms supports at least six electrical traces, and each of the at least three outer arms supports half the number of electrical traces of the central arm.

[0100] Clause 20: A flexible circuit as described in any one of Clauses 17 to 19, wherein the first electrical trace comprises a straight section at the distal end of the proximal portion of the substrate.

[0101] Clause 21: A flexible circuit according to any one of Clauses 17 to 20, wherein the intermediate portion of the substrate is configured to support a second electrical trace, the second electrical trace being spaced a predetermined distance from the inner radius of each bend.

[0102] 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.

[0103] [Implementation Method] (1) A flexible circuit for the end effector of a medical probe, wherein the end effector extends along its longitudinal axis, and the flexible circuit is A first substrate supporting a first electrical trace extending along a portion of the end effector, wherein the first electrical trace has a plurality of bends such that the first electrical trace defines a meandering shape, A flexible circuit comprising: a second substrate laminated in the thickness direction with the first substrate and supporting a second electrical trace extending along the portion of the end effector, wherein the second electrical trace has a plurality of bends such that the second electrical trace defines a meandering shape, and the second electrical trace is offset from the first electrical trace at one or more of the plurality of bends. (2) The flexible circuit according to Embodiment 1, wherein the first substrate has a width equal to the width of the second substrate along the portion of the end effector. (3) The flexible circuit according to Embodiment 2, wherein the first electrical trace is located at a first distance from the edge of the first substrate, and the second electrical trace is located at a second distance from the corresponding edge of the second substrate, and the first distance is smaller or larger than the second distance. (4) The flexible circuit according to Embodiment 1, wherein the second electrical trace is offset from the first electrical trace at the distal angle of the flexible circuit. (5) The flexible circuit according to Embodiment 1, wherein the first substrate comprises at least two electrodes.

[0104] (6) The flexible circuit according to Embodiment 5, wherein the first electrical trace extends between the at least two electrodes and connects the at least two electrodes to each other. (7) The flexible circuit according to Embodiment 6, wherein the second electrical trace extends between the at least two electrodes and connects the at least two electrodes to each other. (8) A flexible circuit for the end effector of a medical probe, wherein the end effector extends along a longitudinal axis, and the flexible circuit is A flexible circuit comprising a substrate for supporting an electrical trace extending along a portion of the end effector, wherein the substrate has a plurality of bends such that the substrate defines a meandering shape, the plurality of bends of the substrate are offset by an offset angle with respect to the longitudinal axis, and the electrical trace is spaced a predetermined distance from the inner radius of each bend. (9) The flexible circuit according to Embodiment 8, wherein the offset angle is approximately 10 to 35 degrees. (10) The flexible circuit according to Embodiment 8, wherein the offset angle is approximately 10 to 20 degrees.

[0105] (11) The flexible circuit according to Embodiment 8, wherein the plurality of bends include two bends along the portion of the end effector extending between two electrodes. (12) The flexible circuit according to embodiment 11, wherein the two bent portions are provided between electrodes in the intermediate portion of the flexible circuit. (13) The flexible circuit according to Embodiment 8, wherein the inner radius of each bend is at least about 0.03 millimeters. (14) The flexible circuit according to Embodiment 8, wherein the inner radius of each bent portion is approximately 0.01 mm to approximately 0.07 mm. (15) The flexible circuit according to Embodiment 8, wherein the flexible circuit comprises a plurality of electrical traces, and the predetermined distance is measured between the innermost edge of the substrate at the inner radius of each bend and the innermost electrical trace closest to the innermost edge.

[0106] (16) The flexible circuit according to Embodiment 15, wherein the predetermined distance between the inner radius of each bend and the innermost electrical trace is at least three times the radius of the innermost electrical trace at each bend. (17) A flexible circuit for the end effector of a medical probe, wherein the end effector extends along a longitudinal axis, and the flexible circuit is A substrate comprising a proximal portion extending distally from the proximal end of the flexible circuit toward a first set of electrodes among a plurality of electrodes, wherein the substrate is configured to support a first electrical trace, and the first electrical trace comprises a plurality of bends such that the electrical trace has a meandering shape, The substrate comprises an intermediate portion extending between the first set of electrodes and the second set of electrodes, and the substrate comprises a plurality of bent portions such that the intermediate portion defines a meandering shape, and the bent portions are offset by an offset angle with respect to the longitudinal axis, wherein the substrate is a flexible circuit. (18) The flexible circuit according to embodiment 17, wherein the proximal portion of the substrate comprises at least three arms extending from the proximal end of the flexible circuit to the first set of electrodes, each arm supporting a plurality of electrical traces. (19) The flexible circuit according to embodiment 18, wherein the central arm of the at least three arms supports at least six electrical traces, and each outer arm of the at least three arms supports half the number of electrical traces of the central arm. (20) The flexible circuit according to embodiment 17, wherein the first electrical trace has a linear section at the distal end of the proximal portion of the substrate.

Claims

1. A flexible circuit for the end effector of a medical probe, wherein the end effector extends along its longitudinal axis, and the flexible circuit is A first substrate supporting a first electrical trace extending along a portion of the end effector, wherein the first electrical trace has a plurality of bends such that the first electrical trace defines a meandering shape, A flexible circuit comprising: a second substrate laminated in the thickness direction with the first substrate and supporting a second electrical trace extending along the portion of the end effector, wherein the second electrical trace has a plurality of bends such that the second electrical trace defines a meandering shape, and the second electrical trace is offset from the first electrical trace at one or more of the plurality of bends.

2. The flexible circuit according to claim 1, wherein the first substrate has a width equal to the width of the second substrate along the portion of the end effector.

3. The flexible circuit according to claim 2, wherein the first electrical trace is positioned at a first distance from the edge of the first substrate, and the second electrical trace is positioned at a second distance from the corresponding edge of the second substrate, the first distance being smaller or larger than the second distance.

4. The flexible circuit according to claim 1, wherein the second electrical trace is offset from the first electrical trace at the distal angle of the flexible circuit.

5. The flexible circuit according to claim 1, wherein the first substrate comprises at least two electrodes.

6. The flexible circuit according to claim 5, wherein the first electrical trace extends between the at least two electrodes and connects the at least two electrodes to each other.

7. The flexible circuit according to claim 6, wherein the second electrical trace extends between the at least two electrodes and connects the at least two electrodes to each other.

8. A flexible circuit for the end effector of a medical probe, wherein the end effector extends along its longitudinal axis, and the flexible circuit is A flexible circuit comprising a substrate for supporting an electrical trace extending along a portion of the end effector, wherein the substrate has a plurality of bends such that the substrate defines a meandering shape, the plurality of bends of the substrate are offset by an offset angle with respect to the longitudinal axis, and the electrical trace is spaced a predetermined distance from the inner radius of each bend.

9. The flexible circuit according to claim 8, wherein the offset angle is approximately 10 to 35 degrees.

10. The flexible circuit according to claim 8, wherein the offset angle is approximately 10 to 20 degrees.

11. The flexible circuit according to claim 8, wherein the plurality of bends include two bends along the portion of the end effector extending between two electrodes.

12. The flexible circuit according to claim 11, wherein the two bent portions are provided between electrodes in the intermediate portion of the flexible circuit.

13. The flexible circuit according to claim 8, wherein the inner radius of each bend is at least about 0.03 millimeters.

14. The flexible circuit according to claim 8, wherein the inner radius of each bent portion is approximately 0.01 mm to approximately 0.07 mm.

15. The flexible circuit according to claim 8, wherein the flexible circuit comprises a plurality of electrical traces, and the predetermined distance is measured between the innermost edge of the substrate at the inner radius of each bend and the innermost electrical trace closest to the innermost edge.

16. The flexible circuit according to claim 15, wherein the predetermined distance between the inner radius of each bend and the innermost electrical trace is at least three times the radius of the innermost electrical trace at each bend.

17. A flexible circuit for the end effector of a medical probe, wherein the end effector extends along its longitudinal axis, and the flexible circuit is A substrate comprising a proximal portion extending distally from the proximal end of the flexible circuit toward a first set of electrodes among a plurality of electrodes, wherein the substrate is configured to support a first electrical trace, and the first electrical trace comprises a plurality of bends such that the electrical trace has a meandering shape, The substrate comprises an intermediate portion extending between the first set of electrodes and the second set of electrodes, and the substrate comprises a plurality of bent portions such that the intermediate portion defines a meandering shape, and the bent portions are offset by an offset angle with respect to the longitudinal axis, wherein the substrate is a flexible circuit.

18. The flexible circuit according to claim 17, wherein the proximal portion of the substrate comprises at least three arms extending from the proximal end of the flexible circuit to the first set of electrodes, each arm supporting a plurality of electrical traces.

19. The flexible circuit according to claim 18, wherein the central arm of the at least three arms supports at least six electrical traces, and each of the at least three outer arms supports half the number of electrical traces of the central arm.

20. The flexible circuit according to claim 17, wherein the first electrical trace has a linear section at the distal end of the proximal portion of the substrate.

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