Surface-mounted electrode catheter

Abstract

To provide a medical system.SOLUTION: In one embodiment, a medical system includes a catheter configured to be inserted into a body part of a living subject, and including an elongated deflectable element including a distal end, a proximal coupler connected to the distal end, an expandable assembly comprising a plurality of flexible polymer circuit strips, the flexible polymer circuit strips having respective proximal ends connected to, and disposed circumferentially around, the proximal coupler, the flexible polymer circuit strips including respective multiple strip electrodes, respective contact arrays disposed at the respective proximal ends, and respective multiple circuit traces electrically connecting the respective multiple strip electrodes with the respective contact arrays, and a plurality of surface-mountable electrodes mounted on, and bulging over, the respective flexible polymer circuit strips.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] (Related Application Information) This application claims priority to U.S. Provisional Patent Application No. 63 / 076,614 to Beeckler et al. (Attorney Docket No. BIO6402USPSP1), filed September 10, 2020, the disclosure of which is incorporated herein by reference.

[0002] FIELD OF THE INVENTION The present invention relates to medical devices, particularly but not exclusively to catheters having electrodes. [Background technology]

[0003] A wide variety of medical procedures involve the placement of probes, such as catheters, inside a patient's body. Position sensing systems have been developed to track such probes. Magnetic position sensing is one method known in the art. In magnetic position sensing, magnetic field generators are typically placed at known locations outside the patient. A magnetic field sensor in the distal end of the probe generates electrical signals in response to these magnetic fields, and these signals are processed to determine the coordinate position of the distal end of the probe. These methods and systems are described in U.S. Patent Nos. 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612, and 6,332,089, PCT Publication No. WO 1996 / 005768, and U.S. Patent Application Publication Nos. 2002 / 0065455, 2003 / 0120150, and 2004 / 0068178. Position may also be tracked using impedance or current-based systems.

[0004] One medical procedure in which these types of probes or catheters have proven extremely useful is in the treatment of cardiac arrhythmias, which, and atrial fibrillation in particular, continue to be a common and dangerous condition, especially in the aging population.

[0005] Diagnosis and treatment of cardiac arrhythmias involve mapping the electrical properties of cardiac tissue, particularly the endocardium and cardiac volumes, and selectively ablating cardiac tissue through the application of energy. Such ablation can stop or modify the propagation of unwanted electrical signals from one part of the heart to another. The ablation process destroys unwanted electrical pathways by creating non-conductive lesions. Various energy delivery modalities have been previously disclosed for creating lesions, including the use of microwave, laser, and more generally radiofrequency energy to create conduction blocks along cardiac tissue walls. In a two-step mapping-then-ablation procedure, a catheter containing one or more electrical sensors is typically advanced into the heart to obtain data at multiple points to detect and measure electrical activity at each point within the heart. These data are then used to select a target region of the endocardium for this ablation.

[0006] Electrode catheters have been commonly used in medical practice for many years. They are used to stimulate and map electrical activity within the heart and to ablate sites of abnormal electrical activity. In use, an electrode catheter is inserted into a major vein or artery, such as the femoral vein, and then guided into the heart chamber of interest. A typical ablation procedure involves inserting a catheter with one or more electrodes at its distal end into a heart chamber. A reference electrode is typically taped to the patient's skin or may be provided by a second catheter placed in or near the heart. Radio frequency (RF) current is applied between the tip electrode of the ablation catheter and the reference electrode, and current flows between the electrodes, i.e., through the medium between the blood and the tissue. The distribution of the current depends on the amount of electrode surface in contact with the tissue compared to the blood, which has a higher electrical conductivity than the tissue. Tissue heating occurs due to the electrical resistance of the tissue. Sufficient tissue heating can cause cell destruction in the cardiac tissue, resulting in the formation of lesions within the non-conductive cardiac tissue.

[0007] U.S. Patent Publication No. 2014 / 0276733 to VanScoy et al. describes an ablation catheter including an elongated body having a proximal end and a distal end. At least one ablation element is disposed on the body between the proximal end and the distal end and configured to ablate renal tissue to control hypertension. At least one localization sensor is disposed on the body and configured to interact with a magnetic field. The at least one localization sensor aids in determining appropriate target tissue for ablation.

[0008] U.S. Patent Publication No. 2008 / 0125772 to Stone et al. describes a catheter and catheter system that uses tailored energy for the remodeling and / or removal of targeted material along a body lumen, often atherosclerotic material in a patient's blood vessels. An elongated, flexible catheter body having a radially expandable structure may have multiple electrodes or other electrosurgical energy delivery surfaces to radially engage the atherosclerotic material when the structure expands. The atherosclerotic material detector system can optionally use impedance monitoring to measure and / or characterize the atherosclerotic material and its location.

[0009] U.S. Patent Publication No. 2011 / 0137298 to Nguyen et al. describes an ablation device comprising an ultrasonic transducer including a piezoelectric element having a cylindrical shape, a plurality of external electrodes disposed on the outer surface of the piezoelectric element, and at least one internal electrode disposed on the inner surface of the piezoelectric element. The internal electrode provides corresponding internal electrode portions disposed on opposite sides of the piezoelectric element from the external electrodes, and the external electrode and the at least one internal electrode are energized to apply an electric field across the piezoelectric element. The ultrasonic ablation zones of the external electrodes are distributed in a staggered configuration to span one or more open arc segments about a longitudinal axis, and the ultrasonic ablation zones of all the external electrodes projected longitudinally on any transverse plane perpendicular to the longitudinal axis span a substantially closed loop about the longitudinal axis.

[0010] U.S. Patent Publication No. 2012 / 0067640 to Moulin et al. describes an electrical connection that makes it possible to achieve a leak-free electrical connection in an environment exposed to corrosive gases or liquids, the connection comprising at least two conductors for forming electrical connections between each other or between connector elements, an outer insulating layer formed on each of the conductors and made of a fluorinated polymer that can melt at a temperature between the temperature of the environment and a predetermined higher temperature, and a heat shrink sleeve surrounding the conductors and made of an outer layer of heat shrinkable polymer and an inner layer of a fluorinated polymer that can melt at a temperature between the temperature of the environment and the predetermined higher temperature, and by heating to a temperature higher than the temperature of the environment and lower than the predetermined higher temperature, the outer insulating layer of the conductor and the inner layer of the heat shrinkable sleeve are melted, thereby producing a continuous, leak-free, and controlled-thickness weld.

[0011] U.S. Patent Publication No. 2013 / 0131661 to Jackson et al. describes a method and device for treating abnormal mucosa in the esophagus such that the depth of the treated tissue is controlled. The depth of ablation is controlled by monitoring tissue impedance and / or tissue temperature. The desired ablation depth is also achieved by controlling the energy density or power density and the amount of time required for energy delivery. A method and device for measuring the internal diameter of a body cavity is disclosed in which a balloon is inflated within the body cavity at a fixed pressure.

[0012] U.S. Pat. No. 3,359,525 describes an electric heating element having thermal stability up to temperatures of about 600°F, comprising: (a) an electric heating unit comprising carbon dispersed in a binder of a material selected from the group consisting of aromatic polyimides, aromatic polyamides, and aromatic polybenzimidazoles, the electric heating unit having means for connecting the electric heating unit to a power source; and (b) an electrically insulating, thermally conductive coating in adhering contact with a surface of the unit, the electrically insulating, thermally conductive coating comprising a polymer selected from the group consisting of aromatic polyimides, aromatic polyamides, and aromatic polybenzimidazoles. Summary of the Invention [Means for solving the problem]

[0013] According to an embodiment of the present disclosure, there is provided a medical system including a catheter configured to be inserted into a body portion of a living subject, the catheter comprising: an elongated, deflectable element including a distal end; a proximal coupler connected to the distal end; an expandable assembly including a plurality of flexible polymer circuit strips, the flexible polymer circuit strips having respective proximal ends connected to the proximal coupler and arranged circumferentially around the periphery of the proximal coupler, each of the flexible polymer circuit strips including a respective plurality of strip electrodes, a respective contact array disposed at the respective proximal end, and a respective plurality of circuit traces electrically connecting each of the plurality of strip electrodes to the respective contact array; and a plurality of surface-mountable electrodes attached to and overhanging each of the flexible polymer circuit strips.

[0014] Furthermore, in accordance with an embodiment of the present disclosure, the catheter further includes first insulated electrical wires disposed within the elongated deflectable element, wherein each group of the first insulated electrical wires is electrically connected to a respective contact array of the flexible polymer circuit strip, and second insulated electrical wires disposed within the elongated deflectable element, wherein each of the second insulated electrical wires extends outside of a respective flexible polymer circuit strip and is electrically connected to a respective surface-mountable electrode.

[0015] Still further, according to an embodiment of the present disclosure, the first insulated electrical wire includes an electrically insulating material configured with a temperature rating of 150-200 degrees Celsius, and the second insulated electrical wire includes an electrically insulating material configured with a temperature rating of greater than 200 degrees Celsius.

[0016] Further, according to an embodiment of the present disclosure, each of the first insulated electrical wires has a first wire gauge and each of the second insulated electrical wires has a second wire gauge, the first wire gauge being larger than the second wire gauge.

[0017] Furthermore, according to an embodiment of the present disclosure, the catheter includes a respective shrink sleeve that secures each of the second wires to each of the flexible polymer circuit strips.

[0018] Furthermore, according to an embodiment of the present disclosure, each of the surface-mountable electrodes is attached to the exterior of the respective shrink sleeve of each of the flexible polymer circuit strips.

[0019] Still further, in accordance with an embodiment of the present disclosure, the catheter includes respective cable jackets disposed within the elongate, flexible element, with respective groups of first insulated electrical wires disposed within the respective cable jackets, and with respective second insulated electrical wires surrounded by respective groups of first insulated wires and disposed within the respective cable jackets.

[0020] Furthermore, according to an embodiment of the present disclosure, each of the surface-mountable electrodes extends around a respective flexible polymer circuit strip.

[0021] Further, according to an embodiment of the present disclosure, the system includes an ablation power generator connected to the catheter and configured to apply an electrical signal to at least one of the surface-mountable electrodes to ablate tissue at the body site, and a mapping module configured to receive the electrical signal from one of the strip electrodes of the flexible polymer circuit strip and generate an electro-anatomical map in response to the received electrical signal.

[0022] Further, according to an embodiment of the present disclosure, a catheter includes a pusher including a distal portion and configured to be advanced and retracted through a deflectable element, the catheter including a distal link connected to the distal portion of the pusher, flexible polymer circuit strips disposed circumferentially around the distal portion of the pusher, the flexible polymer circuit strips having respective distal ends connected to the distal links, the strips configured to arc radially outward when the pusher is retracted to expand the expandable assembly from a collapsed configuration to an expanded configuration.

[0023] Also provided according to another embodiment of the present disclosure is a catheter device configured to be inserted into a body part of a living subject, the catheter device including: an elongated, deflectable element including a distal end; a distal tip assembly disposed at the distal end, the distal tip assembly including a plurality of first electrodes and a plurality of second electrodes; first insulated electrical wires disposed within the elongated, deflectable element, each of the first insulated electrical wires electrically connected to a respective one of the first electrodes, the first insulated electrical wires comprising an electrically insulating material configured to have a temperature rating of 150-200°C; and a second insulated electrical wire disposed within the elongated, deflectable element, each of the second insulated electrical wires electrically connected to a respective one of the second electrodes, the second insulated electrical wire comprising an electrically insulating material configured to have a temperature rating of greater than 200°C.

[0024] Still further, in accordance with an embodiment of the present disclosure, the device includes a shrink sleeve covering at least a portion of the second insulated electrical wire.

[0025] Also provided in accordance with yet another embodiment of the present disclosure is a method of manufacturing a catheter, the method including: providing a catheter, the catheter comprising: an elongated, deflectable element; a proximal coupler connected to a distal end of the elongated, deflectable element; and an expandable assembly including a plurality of flexible polymer circuit strips, the flexible polymer circuit strips having respective proximal ends connected to the proximal coupler and arranged circumferentially around the proximal coupler, each of the flexible polymer circuit strips including a respective plurality of strip electrodes, a respective contact array disposed at the respective proximal end, and a respective plurality of circuit traces electrically connecting each of the plurality of strip electrodes to the respective contact array; and attaching a plurality of surface-mountable electrodes on each of the flexible polymer circuit strips, the surface-mountable electrodes overhanging each of the flexible polymer circuit strips.

[0026] Further, according to an embodiment of the present disclosure, the method includes disposing first insulated electrical wires within the elongated deflectable element, electrically connecting respective groups of the first insulated electrical wires to respective contact arrays of respective flexible polymer circuit strips, disposing second insulated electrical wires within the elongated deflectable element, extending each of the second insulated electrical wires outside of each of the flexible polymer circuit strips, and electrically connecting each of the second insulated electrical wires to a respective surface-mountable electrode.

[0027] Further, according to an embodiment of the present disclosure, electrically connecting each group of first insulated electrical wires includes melting the electrical insulating material of the first wires, and electrically connecting each of the second insulated electrical wires includes mechanically stripping the electrical insulating material of the second insulated electrical wires.

[0028] Further, according to an embodiment of the present disclosure, each of the first insulated electrical wires has a first wire gauge and each of the second insulated electrical wires has a second wire gauge, the first wire gauge being larger than the second wire gauge.

[0029] Still further, according to an embodiment of the present disclosure, the method includes shrink wrapping each of the second insulated electrical wires onto a respective flexible polymer circuit strip.

[0030] Further, according to an embodiment of the present disclosure, the method includes disposing a respective shrink sleeve around each of the second insulated electrical wires and each of the flexible polymer circuit strips, pulling each of the second insulated electrical wires through a respective hole in the shrink sleeve, heat shrinking a respective distal portion of the respective shrink sleeve, sliding each of the surface-mountable electrodes over the respective heat-shrunk distal portion of the respective shrink sleeve, electrically connecting each of the second insulated electrical wires to the respective surface-mountable electrodes, removing slack in each of the second insulated electrical wires, and heat shrinking a respective proximal portion of the respective shrink sleeve.

[0031] Further, in accordance with an embodiment of the present disclosure, the method includes disposing respective groups of first insulated electrical wires within respective cable jackets, and disposing respective second insulated electrical wires within respective cable jackets surrounded by respective groups of first insulated wires. [Brief explanation of the drawings]

[0032] The present invention will be understood from the following detailed description taken in conjunction with the accompanying drawings. [Figure 1] 1 is a partially pictorial, partially block diagram of a medical system constructed and operative in accordance with an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic diagram of a catheter of the system of FIG. 1. [Figure 3] FIG. 3 is a partially exploded view of the catheter of FIG. 2. [Figure 4A] FIG. 3 is a schematic diagram of the distal end of the catheter of FIG. 2 without the distal electrode. [Figure 4B] FIG. 3 is a schematic diagram of the distal end of the flexible polymer circuit strip of the catheter of FIG. 2. [Figure 4C] FIG. 3 is a schematic diagram of the distal end of the flexible polymer circuit strip of the catheter of FIG. 2. [Figure 5] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 6] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 7A] 2A-2C are schematic diagrams showing the catheter of FIG. 1 in a deployed and collapsed configuration, respectively. [Figure 7B] 2A-2C are schematic diagrams showing the catheter of FIG. 1 in a deployed and collapsed configuration, respectively. [Figure 8] FIG. 3 is a schematic diagram of the flexible polymer circuit strip of the catheter of FIG. 2. [Figure 9] FIG. 3 is a schematic diagram of the flexible polymer circuit strip of the catheter of FIG. 2 showing the circuit traces. [Figure 10] FIG. 3 is a schematic diagram of the flexible polymer circuit strip of the catheter of FIG. 2 showing the circuit traces. [Figure 11] FIG. 9 is a schematic diagram of the flexible polymer circuit strip of FIG. 8 with surface-mountable electrodes attached. [Figure 12] FIG. 12 is a more detailed view of the surface-mountable electrode of FIG. [Figure 13] FIG. 13 is a cross-sectional view taken along line AA in FIG. 12. [Figure 14] FIG. 13 is a cross-sectional view taken along line BB in FIG. [Figure 15] 3 is a flow chart including steps in a method of manufacturing the catheter of FIG. 2. [Figure 16] FIG. 3 is an axial cross-sectional view of an elongated deflectable element of the catheter of FIG. 2. [Figure 17] 17 is an axial cross-sectional view of a cable disposed within the elongated flexible element of FIG. 16. [Figure 18]FIG. 3 is a schematic longitudinal cross-sectional view of an alternative flexible polymer circuit strip for use in the catheter of FIG. 2. [Figure 19] 19 is a flow chart including steps in a method of manufacturing a catheter including the flexible polymer circuit strip of FIG. 18. [Figure 20] 19 is a flowchart including more detailed steps in a method of manufacturing a catheter including the flexible polymer circuit strip of FIG. 18. DETAILED DESCRIPTION OF THE INVENTION

[0033] Overview Diagnostic catheters, such as basket catheters, provide many electrodes for capturing electrical signals, such as electrical potentials, from tissues in a patient's body region. The electrical signals can then be analyzed to provide an indication of the medical condition of the body region. For example, the electrical signals can be used to provide an electroanatomical map. The medical condition of the body region may indicate that a portion of the tissue may require ablation (e.g., radiofrequency (RF) ablation or irreversible electroporation (IRE)) using a suitable catheter. While basket catheter electrodes may be suitable for diagnostic purposes, the electrodes and / or connections to the electrodes may be too small for use in ablation. This is particularly true for IRE, which uses high currents and requires a large electrode surface area to provide effective IRE ablation. Therefore, in such situations, the diagnostic basket catheter is removed from the patient, and a suitable ablation catheter is inserted into the patient's body region to perform the ablation. The use of two catheters may increase the length of the medical procedure, delaying the essential therapeutic procedure, and the time delay and use of two catheters may increase trauma to the patient.

[0034] Embodiments of the present invention solve the above problems by providing a basket catheter that includes both diagnostic and ablation electrodes, thereby providing a combined therapeutic and diagnostic catheter.

[0035] The basket catheter includes a distal expandable assembly made of flexible polymer circuit strips connected together proximally and distally to form a basket. Each strip includes a diagnostic electrode. Each strip also includes an ablation electrode connected to the strip. The ablation electrode of each strip may slide over the strip, may be wrapped around the strip, or may be formed from two sections connected together around the strip.

[0036] In some embodiments, the ablation electrodes are connected to the flexible polymer circuit strip in a staggered arrangement with alternating ablation electrodes disposed more proximally than the other to allow for compact storage of the expandable assembly during insertion and removal of the catheter into and from the patient.

[0037] In some embodiments, each strip includes contact pads generally formed in the same or similar manner as the diagnostic electrodes. In disclosed embodiments, the contact pads are larger than the diagnostic electrodes. The ablation electrodes are connected to their respective contact pads using a suitable bonding method, such as using solder, conductive epoxy, resistance welding, laser welding, or any other suitable method, to provide an electrical connection between each ablation electrode and its corresponding contact pad. The ablation electrodes may be connected using one or two bonding portions. The ablation electrodes are also referred to herein as surface-mountable electrodes. The diagnostic electrodes are also referred to herein as strip electrodes. Adhesives may also be used to connect the surface-mountable electrodes to the strips in addition to bonding.

[0038] In other embodiments, the ablation electrodes are electrically connected via wires that extend along the inner surface of the respective flexible polymer circuit strips and through the elongated deflectable element of the catheter to the proximal end of the catheter, and other wires extend from the proximal end of the catheter through the deflectable element to the respective contact arrays on the flexible polymer circuit strips, thereby electrically connecting the diagnostic electrodes to the proximal end of the catheter.

[0039] In some embodiments, the wires from the ablation electrodes and the diagnostic electrodes are bundled within a cable (e.g., within a cable jacket) within the elongated flexible element. In some embodiments, each group of wires from the diagnostic electrodes is bundled with each of the wires from the ablation electrodes, thereby providing better insulation for the ablation electrode wires.

[0040] One problem encountered during catheter manufacturing is due to the miniaturization of elements. For example, a basket catheter may contain tens or even hundreds of electrodes, each requiring a separate electrical connection from the basket to the proximal end of the catheter. Connecting wires extending from the proximal end of the catheter to the contact array (e.g., solder pads) on the flexible polymer circuit strip or other elements containing electrodes is challenging. One solution is to use insulated wire with a low-temperature rating (e.g., above 150°C but below 200°C) so that when solder is applied to the end of the wire (e.g., at about 300°C), the wire insulation melts or degrades, thereby allowing the wire to be connected to the contact array without having to strip the insulation from the wire. However, using low-temperature rated wire can be problematic when dealing with high-temperature conditions during catheter manufacturing or use. For example, when a heat-shrink sleeve is heated, the wire insulation may melt or degrade (e.g., carbonize and disintegrate), leading to an electrical short between the wire and a conductive element, such as the metal support of the flexible polymer circuit strip.

[0041] Thus, embodiments of the present invention solve the above problem by providing a catheter (e.g., a basket catheter, or any other suitable catheter, such as a balloon catheter or Lasso catheter) that uses insulated wire with a low temperature rating (e.g., 150-200°C) to electrically connect electrodes when the wire insulation is not subject to melting or thermal degradation except when soldering connections or when the wire insulation is not critical (e.g., lack of insulation does not lead to short circuits), and that uses insulated wire with a higher temperature rating (e.g., above 200°C) to electrically connect electrodes when heat is applied to the wire during manufacture and / or use of the catheter and could lead to short circuits or other problems.

[0042] As used in this specification and claims, the term "temperature rating" is defined as the maximum continuous temperature that a wire insulation can withstand during its life without causing thermal damage, such as melting or thermal degradation (e.g., carbonization and embrittlement) of the wire insulation.

[0043] In some embodiments, the catheter uses wires (extending from the proximal end of the catheter) that are electrically connected to the contact array (which is then electrically connected to the diagnostic electrodes on the circuit strip via the circuit traces) with a low temperature rating (e.g., between 150 and 200°C), thereby allowing the wires to be connected using soldering without stripping the insulation from the wires. Other wires extending from the proximal end of the catheter have higher temperature ratings (e.g., above 200°C), which are stripped before being electrically connected to the ablation electrodes mounted on the circuit strip. Wires with higher temperature ratings may be connected to their respective circuit strips using heat shrink sleeves, and the application of heat to the shrink sleeves is not associated with melting or degrading the insulation of the higher temperature rated wires.

[0044] In some embodiments, a mapping module executed by the processor receives electrical signals from at least some of the strip electrodes of the flexible polymer circuit strip and generates an electroanatomical map in response to the received electrical signals. An ablation power generator is connected to the catheter and applies electrical signals to one or more of the surface-mountable electrodes to ablate tissue at the body site (using RF or IRE ablation). In some embodiments, the ablation power generator applies electrical signals between at least some of the surface-mountable electrodes.

[0045] In some embodiments, the catheter may include an electrode, referred to herein as a distal electrode, located at the distal tip of the catheter between the distal ends of the strips. The distal electrode may be used for ablation. In some embodiments, an ablation power generator applies an electrical signal between one or more of the surface-mountable electrodes and the distal electrode to ablate tissue at the body site (using RF or IRE ablation).

[0046] System Description Reference is now made to Figure 1, which is a partially pictorial, partially block diagram of a medical system 10 constructed and operative in accordance with an embodiment of the present invention. Medical system 10 includes a catheter 12 configured to be inserted into a body region 14 (e.g., a cardiac chamber) of a living subject.

[0047] Catheter 12 includes an elongated deflectable element 16 including a distal end 18. Elongated deflectable element 16 may have any suitable outer diameter and length, for example, the outer diameter may range from 1 mm to 4 mm and the length may range from 1 cm to 15 cm.

[0048] The catheter 12 also includes a proximal connector 20 connected to the distal end 18. The proximal connector 20 may be formed as an integral part of the deflectable element 16 or as a separate element and then connected to the distal end 18 using any suitable connection method, such as using an adhesive, e.g., epoxy. The catheter 12 also includes an expandable distal end assembly 22 including flexible polymer circuit strips 24 (only some of which are labeled for simplicity). Each flexible polymer circuit strip 24 includes a plurality of strip electrodes 26 (only some of which are labeled for simplicity) and respective contact pads 28 disposed thereon. The contact pads 28 are mostly obscured in FIG. 1 and are more clearly shown in FIGS. 8-10, 13, and 14. The catheter 12 includes a pusher 30 including a distal portion 32. The pusher 30 is configured to advance and retract through the deflectable element 16. Catheter 12 also includes a distal connector 34 connected to the distal portion 32 of pusher 30. A proximal end of flexible polymer circuit strip 24 is connected to proximal connector 20, and a distal end of flexible polymer circuit strip 24 is connected to distal connector 34, with flexible polymer circuit strip 24 disposed circumferentially around distal portion 32 of pusher 30. Flexible polymer circuit strip 24 is configured to bow radially outward when pusher 30 is retracted to expand the expandable assembly from the collapsed configuration to the expanded configuration, as described in more detail with reference to Figures 7A-7B.

[0049] In some embodiments, the catheter 12 includes a distal electrode 36 disposed at the distal tip of the catheter 12 between the distal ends of the flexible polymer circuit strip 24. In other embodiments, the catheter 12 includes a nose cap (not shown) disposed within the distal coupling 34 in place of the distal electrode 36.

[0050] The catheter 12 includes surface-mountable electrodes 38 electrically connected to a respective one of the flexible polymer circuit strips 24. In some embodiments, one surface-mountable electrode 38 is disposed on each flexible polymer circuit strip 24. The surface-mountable electrodes 38 are electrically connected to the flexible polymer circuit strips 24 via contact pads 28, as will be described in more detail with reference to FIG.

[0051] The surface-mountable electrodes 38 may be connected at the same location on each flexible polymer circuit strip 24, or may be connected in a staggered arrangement with alternating surface-mountable electrodes 38 disposed more proximally than other surface-mountable electrodes 38 so that the expandable assembly 22 can be efficiently compressed when retracted during insertion into and removal from the patient's body part 14.

[0052] In some embodiments, the surface-mountable electrode 38 may be connected to any suitable basket catheter having elements different from those of the catheter 12 .

[0053] The medical system 10 includes an ablation power generator 40 configured to connect to the catheter 12. The ablation power generator 40 may be housed within a console 42. The ablation power generator 40 is configured to apply an electrical signal to one or more of the surface-mountable electrodes 38 to ablate tissue at the body region 14. In some embodiments, the ablation power generator 40 is configured to apply an electrical signal between some of the surface-mountable electrodes 38 to ablate tissue (using RF or IRE ablation). In some embodiments, the ablation power generator 40 is configured to apply an electrical signal between one or more of the surface-mountable electrodes 38 and the distal electrode 36 to ablate tissue at the body region 14 (using RF or IRE ablation).

[0054] The medical system 10 includes a processor 44 configured to execute a mapping module 46 configured to receive electrical signals from at least some of the strip electrodes 26 of the flexible polymer circuit strip 24 and to generate an electroanatomical map 48 in response to the received electrical signals.

[0055] In practice, some or all of the functions of processor 44 may be combined into a single physical component, or alternatively, may be embodied using multiple physical components. These physical components may comprise hardwired or programmable devices, or a combination of the two. In some embodiments, at least some of the functions of processor 44 may be performed by a programmable processor under the control of suitable software. This software may be downloaded to the device in electronic form, for example, over a network. Alternatively or additionally, this software may be stored on a tangible, non-transitory computer-readable medium, such as optical, magnetic, or electronic memory.

[0056] The medical system 10 may include other modules and elements not shown for simplicity, such as an electrocardiogram module, a display screen, and user input devices (e.g., a keyboard and mouse), by way of example only.

[0057] Reference is now made to Figure 2, which is a schematic diagram of the catheter 12 of the system 10 of Figure 1. Figure 2 shows in greater detail the proximal connector 20, the distal connector 34, the flexible polymer circuit strip 24 (only some of which are labeled for simplicity), the pusher 30, and the surface-mountable electrodes 38 (only some of which are labeled for simplicity).

[0058] The inner diameter of the pusher 30 is sized to accommodate a wire. The pusher 30 may be formed from any suitable material, such as, but not limited to, polyimide with or without braid, polyether ether ketone (PEEK) with or without braid, or polyamide with or without braid. The distal link 34 and the proximal link 20 may be formed from any suitable material, such as, but not limited to, polycarbonate with or without glass filler, PEEK with or without glass filler, or PEI with or without glass filler.

[0059] The catheter 12 includes elongated elastic support elements 50 (only some of which are labeled for simplicity) connected along a given length of each of the flexible polymer circuit strips 24, which provide the shape of the expandable assembly 22 in its expanded configuration. The elongated elastic support elements 50 may comprise any suitable material, such as, but not limited to, nitinol and / or polyetherimide (PEI). The elongated elastic support elements 50 extend from the proximal connector 20 along the inner surface of each flexible polymer circuit strip 24 until just before the flexible polymer circuit strip 24 enters the distal connector 34, as described in more detail with reference to FIGS. 4A-4C, allowing the flexible polymer circuit strip 24 to flex sufficiently at that point. The elongated elastic support elements 50 may have any suitable thickness, for example, in the range of approximately 0.025 mm to 0.25 mm.

[0060] Reference is now made to Figure 3, which is a partially exploded view of the catheter 12 of Figure 2. Figure 3 shows the catheter 12 with the distal electrode 36 (or nose piece) and the proximal connector 20 removed to show how the flexible polymer circuit strip 24 is connected to the distal connector 34 and the proximal connector 20. The proximal end of the flexible polymer circuit strip 24 is connected to the inner surface of the proximal connector 20 and is disposed circumferentially around the inner surface of the proximal connector 20. The distal end of the flexible polymer circuit strip 24 is connected to the inner surface of the distal connector 34 and is disposed circumferentially around the inner surface of the distal connector 34. The flexible polymer circuit strip 24 may be connected to the proximal connector 20 and the distal connector 34 using any suitable method, for example, using an adhesive (e.g., epoxy) and / or using a pressure fit. The distal end of the flexible polymer circuit strip 24 is generally bent over and connected to the distal end of the distal connector 34, allowing the flexible polymer circuit strip 24 to bend approximately 90 degrees to form a flat nose catheter. In some embodiments, the distal ends of the flexible polymer circuit strip 24 may be connected to the outer surface of the distal connector 34 or may be connected together without the use of a distal connector.

[0061] Reference is now made to Figure 4A, which is a schematic illustration of the distal end of the catheter 12 of Figure 2 without the distal electrode 36. Reference is also now made to Figures 4B-4C, which are schematic illustrations of the distal end of one of the flexible polymer circuit strips 24 of the catheter 12 of Figure 2. Figure 4A shows that the distal end of the flexible polymer circuit strip 24 is bent into the distal connector 34. In some embodiments, the distal end of the flexible polymer circuit strip 24 is tapered so that the flexible polymer circuit strip 24 fits into the distal connector 34.

[0062] As previously mentioned, the flexible polymer circuit strips 24 are supported using elongated, resilient support elements 50 that extend from the proximal end of the flexible polymer circuit strips 24 to the hinge sections 52 of each flexible polymer circuit strip 24. The hinge sections 52 may be reinforced using any suitable material. In some embodiments, the hinge sections 52 are reinforced using threads 54 (FIG. 4B) that extend from between the flexible polymer circuit strips 24 and the elongated, resilient support elements 50 to the distal end of the flexible polymer circuit strips 24. The threads 54 may include any one or more of ultra-high molecular weight polyethylene threads or threads spun from liquid crystal polymers. The threads 54 may be of any suitable linear density, for example, in the range of approximately 25 denier to 250 denier. The flexible polymer circuit strip 24, elongated elastic support element 50, and thread 54 may be connected together using any suitable method, for example, an adhesive such as epoxy, and may be covered with a suitable covering 56 (e.g., FIGS. 4B and 4C), for example, a thermoplastic polyethylene terephthalate (PET) shrink sleeve. Windows are opened in covering 56 to expose strip electrodes 26 and contact pads 28 (FIG. 1).

[0063] Also, in FIG. 4B, it can be seen that the hinge section 52 is much thinner (having a thickness "t") than the region containing the elongated resilient support element 50. The hinge section 52 may have any suitable thickness, for example, within a range of approximately 10 to 140 micrometers. The hinge section 52 includes a first portion 52A having a width w1 (FIG. 4A), which tapers to a narrower width w2 at the second portion 52B. The hinge section 52 further narrows from width w2 (at 52B) to width w3 at the end 52C. Width 52A is approximately twice width 52C. The length L of the final portion 52C is approximately 3 mm, ensuring that the flexible polymer circuit strip 24 can be retained within the connector 34 without separation.

[0064] Reference is now made to Figure 5, a cross-sectional view taken through line AA in Figure 1. Figure 5 shows how the distal end of the flexible polymer circuit strip 24 is connected to the inner surface of the distal connector 34. A position sensor 58 (such as a magnetic position sensor) is optionally disposed within the distal connector 34. The distal electrode 36 is inserted within the distal connector 34 between the flexible polymer circuit strip 24 and the position sensor 58. Figure 5 also shows how the distal end of the pusher 30 is connected to the proximal end of the distal connector 34.

[0065] Reference is now made to Figure 6, a cross-sectional view through line BB of Figure 1. Figure 6 shows how the proximal end of the flexible polymer circuit strip 24 is connected to the inner surface of the proximal connector 20. Figure 6 also shows that the proximal connector 20 is connected around the outer surface of the deflectable element 16, which includes a lumen 60 for carrying wires and irrigation tubing, for example, from the distal end to the proximal end of the catheter 12. The flexible polymer circuit strip 24 may additionally be held in place using a retaining ring 62. Figure 6 also shows a pusher 30 extending from one of the lumens 60 of the deflectable element 16 into the expandable assembly 22.

[0066] Reference is now made to FIGS. 7A-7B, which are schematic diagrams showing the catheter 12 of FIG. 1 in the deployed and folded configurations, respectively. The flexible polymer circuit strip 24 is configured to bend radially outward when the pusher 30 is retracted to expand the expandable assembly 22 from the folded configuration to the expanded configuration. The folded configuration of the expandable assembly 22 represents the unstressed form of the flexible polymer circuit strip 24, which is given its shape using the elongated, resilient support elements 50 (FIGS. 4A-4C). In some embodiments, the unstressed form of the expandable assembly 22 is the expanded configuration. In some embodiments, the expandable assembly 22 collapses when retracted into a sheath (not shown) without the need for a pusher or similar element.

[0067] In some embodiments, the flexible polymer circuit strip 24 is formed as a flat strip. The distal end of the flexible polymer circuit strip 24 is connected to the inner surface of the distal connector 34, and the proximal end of the flexible polymer circuit strip 24 is then connected to the proximal connector 20, such that in the collapsed configuration, the angle between the tangent to the distal end of the flexible polymer circuit strip 24 and the axis of the pusher 30 is close to 180 degrees, while in the expanded configuration, the angle between the tangent to the distal end of the flexible polymer circuit strip 24 and the axis is approximately 90 degrees. Thus, in operation (when the flexible polymer circuit strip 24 is connected to the distal electrode 36 and the proximal connector 20), the hinge sections 52 are configured to provide a maximum angular range of movement of the flexible polymer circuit strip 24 of approximately 90 degrees, and typically greater than 80 degrees. However, the hinge sections 52 can bend more than 180 degrees.

[0068] Reference is now made to FIG. 8, which is a schematic diagram of one of the flexible polymer circuit strips 24 of the catheter 12 of FIG. 2. The flexible polymer circuit strip 24 shows strip electrodes 26 and contact pads 28. The contact pads 28 are typically formed in the same manner as the strip electrodes 26, except that the contact pads 28 may be longer than each strip electrode 26. In some embodiments, the contact pads 28 may be the same size as the strip electrodes 26. FIG. 8 also shows the hinge section 52 and elongated resilient support element 50 on the underside of the flexible polymer circuit strip 24. The flexible polymer circuit strip 24 also includes a contact array 64 for connecting the strip electrodes 26 and contact pads 28 to wires that extend from the deflectable element 16 (FIG. 1) to the proximal end of the catheter 12.

[0069] Reference is now made to Figures 9 and 10, which are schematic diagrams of one of the flexible polymer circuit strips 24 of the catheter 12 of Figure 2, showing a circuit trace 66. The flexible polymer circuit strip 24 in Figures 9 and 10 is shown in a semi-transparent format, allowing visualization of the different layers of the flexible polymer circuit strip 24. The flexible polymer circuit strip 24 is generally formed from multiple layers, including a lower layer and an upper layer. The lower layer of the flexible polymer circuit strip 24 includes circuit traces 66 that connect the strip electrodes 26 and contact pads 28 to the contact array 64. The upper layer includes the strip electrodes 26 and contact pads 28. The circuit traces 66 on the lower layer are connected to the strip electrodes 26 and contact pads 28 on the upper layer using vias (not shown). The circuit traces 66 to the contact pads 28 may be wider than the other circuit traces 66 and may be spaced further apart from the other circuit traces 66 to ensure proper insulation. The circuit traces 66 of the strip electrodes 26 may be approximately 0.005 mm to 0.1 mm wide (e.g., 0.025 mm) and spaced apart from one another from approximately 0.005 mm to 0.1 mm (e.g., 0.025 mm), while the traces 66 of the contact pads 28 may be approximately 0.025 mm to 0.25 mm wide (e.g., 0.125 mm wide) and spaced apart from one another from approximately 0.010 mm to 0.125 mm (e.g., 0.050 mm). The thickness of the traces 66 may be approximately 0.005 mm to 0.100 mm (e.g., 0.010 mm). In some embodiments, the circuit traces 66 may have the same width and spacing. The flexible polymer circuit strips 24 may be constructed of any suitable material. In some embodiments, each of the flexible polymer circuit strips 24 comprises a strip of polyimide. Circuit traces 66 are disposed on the back surface of the polyimide strip, and strip electrodes 26 and contact pads 28 are disposed on the front surface of the polyimide strip.

[0070] The flexible polymer circuit strip 24 may have any suitable dimensions. For example, the length of the flexible polymer circuit strip 24 may range from 10 mm to 60 mm, such as 30 mm, the width of the flexible polymer circuit strip 24 may range from about 0.25 mm to 3 mm, such as 0.72 mm, and the thickness of the flexible polymer circuit strip 24 may range from about 0.005 mm to 0.14 mm.

[0071] Referring now to FIG. 11 , which is a schematic diagram of the flexible polymer circuit strip 24 of FIG. 8 having a mapping electrode 26 with one of the surface-mountable electrodes 38 mounted thereon. The electrodes 26 are used to record electrocardiogram signals generated by cardiac tissue. Each electrode 26 has a first exposed surface area A1. The surface-mounted electrodes 38 can be used for ablation by delivering DC or AC signals through the electrodes 38. The electrodes 38 have a second exposed surface area A2 that is at least three times the first exposed area of ​​each mapping electrode 26. The exposed surface area A1 is from about 0.08 mm to about 1 mm square. The surface-mountable electrode 38 may be formed as a single element that is slid over the flexible polymer circuit strip 24 and the elongated elastic support element 50. In some embodiments, the surface-mountable electrode 38 may be formed from two halves connected together around the strip 24 and the elongated elastic support element 50. In yet other embodiments, the surface-mountable electrodes 38 may be formed as bands wrapped around the flexible polymer circuit strip 24 and the elongated resilient support element 50. The surface-mountable electrodes 38 may be formed from any suitable material, for example, but not limited to, gold, gold alloys, platinum, platinum alloys, palladium, or palladium alloys.

[0072] Reference is now made to Figure 12, which is a more detailed view of the surface-mountable electrode 38 of Figure 11. The surface-mountable electrode 38 is shown mounted on the contact pad 28. The surface-mountable electrode 38 is electrically connected to the contact pad 28 using two conductive retainers 68 (e.g., using solder, conductive epoxy, resistance welding, laser welding, or any other suitable method). The surface-mountable electrode 38 is further secured to the flexible polymer circuit strip 24 using an adhesive 70, such as a polyurethane glue or epoxy. The adhesive 70 may be applied such that the contact pad 28 is electrically isolated from the environment surrounding the catheter 12.

[0073] Reference is now made to FIG. 13, a cross-sectional view taken through line AA in FIG. 12. FIG. 13 shows that the surface-mountable electrode 38 extends over the contact pad 28 and below the elongated resilient support element 50. FIG. 13 also shows two layers of the flexible polymer circuit strip 24: layer 72 (shown in each of FIGS. 9 and 10) containing the circuit traces 66, and layer 74 (shown in FIG. 10) containing the contact pad 28 and strip electrode 26. The contact pad 28 shown in FIG. 13 is wider than the surface-mountable electrode 38. In some embodiments, the contact pad 28 may be narrower than or the same width as the surface-mountable electrode 38. The surface-mountable electrode 38 is electrically connected to the contact pad 28 using at least one conductive retainer 68. In some embodiments, the proximal and distal ends of the surface-mountable electrode 38 are electrically connected to the contact pad 28 using two respective conductive retainers 68. The proximal and distal ends of the surface-mountable electrodes 38 are optionally connected to the flexible polymer circuit strip 24 using an adhesive 70. The adhesive 70 typically covers the remainder of the contact pads 28 not covered by the surface-mountable electrodes 38. The adhesive 70 may include, by way of example, a polyurethane adhesive or epoxy. While the bonds 68 are typically disposed on the outer surface of the flexible polymer circuit strip 24, the adhesive 70 is generally disposed around the flexible polymer circuit strip 24 and the elongated, resilient support element 50 to secure the surface-mountable electrodes 38 to the flexible polymer circuit strip 24 and the elongated, resilient support element 50 and to prevent liquids from contacting the contact pads 28 during use of the catheter 12.

[0074] Reference is now made to FIG. 14, a cross-sectional view taken through line BB in FIG. 12. FIG. 14 shows a surface-mountable electrode 38 extending around the flexible polymer circuit strip 24 and the elongated, resilient support element 50. FIG. 14 also shows a thread 54 sandwiched between the flexible polymer circuit strip 24 and the elongated, resilient support element 50. A covering 56 (e.g., a shrink sleeve) is shown surrounding the elongated, resilient support element 50 and partially surrounding the flexible polymer circuit strip 24, with a window opened in the covering 56 to expose the contact pads 28. The surface-mountable electrode 38 shown in FIG. 14 is a continuous, hollow electrode that is slid over the combination of the flexible polymer circuit strip 24 and the elongated, resilient support element 50. As previously mentioned, the surface-mountable electrode 38 may be formed from two halves connected together around the strip 24. In yet other embodiments, the surface-mountable electrode 38 may be formed as a band wrapped around the flexible polymer circuit strip 24.

[0075] Reference is now made to Figure 15, which is a flow chart 80 including steps in a method of manufacturing the catheter 12 of Figure 2. Reference is also made to Figure 1.

[0076] The method includes forming each flexible polymer circuit strip 24 from multiple layers (block 82), with layer 72 (FIG. 13) including the circuit traces 66 (FIGS. 9 and 10) and layer 74 (FIG. 13) including the strip electrodes 26 and respective contact pads 28.

[0077] The method includes forming or providing (block 84) a catheter 12 including an elongate deflectable element 16, a proximal connector 20 connected to a distal end 18 of the deflectable element 16, a distal connector 34, a distal electrode 36, a pusher 30, and an expandable assembly 22. The expandable assembly 22 includes flexible polymer circuit strips 24. Each flexible polymer circuit strip 24 includes a respective strip electrode 26 and a respective contact pad 28 disposed thereon. The proximal and distal ends of the flexible polymer circuit strips 24 are connected to the proximal and distal connectors 20 and 34, respectively, and are disposed circumferentially around the proximal and distal connectors 20 and 34. A distal electrode 36 is disposed at the distal tip of the catheter 12 between the distal ends of the flexible polymer circuit strips 24. Pusher 30 is configured to advance and retract through deflectable element 16. A distal portion of pusher 30 is connected to distal connector 34. Flexible polymer circuit strip 24 is disposed circumferentially around the distal portion of pusher 30. Flexible polymer circuit strip 24 is configured to bend radially outward when pusher 30 is retracted to expand expandable assembly 22 from the collapsed configuration to the expanded configuration.

[0078] The method also includes connecting (block 86) the surface-mountable electrodes 38 to respective ones of the flexible polymer circuit strips 24. In some embodiments, the method includes connecting the surface-mountable electrodes 38 to respective ones of the flexible polymer circuit strips 24 in a staggered arrangement, with every other one of the surface-mountable electrodes 38 disposed more proximally than the other one of the surface-mountable electrodes 38. The step of block 86 may include the substeps of blocks 88 and 90, as follows:

[0079] The method may also include electrically connecting the surface-mountable electrodes 38 to respective ones of the flexible polymer circuit strips 24 (block 88), such that each surface-mountable electrode 38 is electrically connected to a respective contact pad 28 of a respective one of the flexible polymer circuit strips 24 using at least one conductive retainer 68 (FIG. 13), for example, using solder, conductive epoxy, resistance welding, laser welding, or any other suitable method. In some embodiments, the method includes electrically connecting a proximal end and a distal end of each surface-mountable electrode 38 to a respective contact pad 28 of a respective flexible polymer circuit strip 24 using two respective conductive retainers 68.

[0080] The method may also include connecting the proximal and distal ends of each surface-mountable electrode 38 to a respective flexible polymer circuit strip 24 using adhesive 70 (block 90).

[0081] Reference is now made to Figure 16, which is an axial cross-sectional view of the deflectable portion 16 of the catheter 12 of Figure 1. The deflectable element 16 includes lumens 60 (only some of which are labeled for simplicity) disposed therein. The lumens 60 may be used to carry cables 92 (only some of which are labeled for simplicity) and / or other elements such as deflection wires, stiffening elements for forming the deflection surface of the deflectable element 16, and puller wires or pushers 30 (Figure 2). The cables 92 are shown disposed within the central lumen 60. In addition to, or instead of, being disposed within the central lumen 60, the cables 92 may be disposed within one or more non-central lumens 60.

[0082] Reference is now made to Figure 17, which is an axial cross-sectional view of one of the cables 92 of Figure 16. The strip electrode 26 (Figure 1) and the surface-mountable electrode 38 (Figure 1) are electrically connected to the proximal end of the catheter 12 (Figure 1) and to the processor 44 (Figure 1) and the ablation power generator 40 (Figure 1) via insulated electrical wires 94 and 96, respectively. In other words, the strip electrode 26 is electrically connected via the insulated electrical wires 94, and the surface-mountable electrode 38 is electrically connected via the insulated electrical wires 96. The insulated electrical wires 94 and 96 are disposed within the cable 92 within the lumen 60 (Figure 16) of the deflectable element 16 (Figure 16).

[0083] In some embodiments, the insulated electrical wires 94 and the insulated electrical wires 96 are disposed within the cable 92 using respective cable jackets 98, such that the cable jackets 98 are disposed within the flexible element 16. In some embodiments, as shown in FIG. 17 , several insulated electrical wires 94 are disposed within one of the cable jackets 98 along with one of the insulated electrical wires 96. Generally, each group of insulated electrical wires 94 (e.g., grouped by the flexible polymer circuit strips 24 to which the insulated electrical wires 94 are connected) is disposed within each of the cable jackets 98 (e.g., using an extruded tube of perfluoroalkoxy alkane (PFA)), and each of the insulated electrical wires 96 is disposed within each of the cable jackets 98, surrounded by each group of insulated electrical wires 94. For example, the insulated electrical wires 94 and the insulated electrical wires 96 are grouped within the cable jacket 98 according to the flexible polymer circuit strips 24 to which the insulated electrical wires 94 and the insulated electrical wires 96 are electrically connected.

[0084] In some embodiments, the wire gauge of each of the insulated electrical wires 94 is greater than the wire gauge of each of the insulated electrical wires 96. The wire gauge of the insulated electrical wires 94 may have any suitable gauge, for example, 48 AWG (American Wire Gauge), and may be formed from any suitable conductor, for example, a copper-silver alloy, which provides additional strength to the thin wires 94. The wire gauge of the insulated electrical wires 96 may have any suitable gauge, for example, 42 gauge, and may be formed from any suitable conductor, for example, copper. The wire gauge of the insulated electrical wires 96 is typically selected to support the electrical current supplied to the surface-mountable electrode 38 during IRE or RF ablation.

[0085] In some embodiments, the insulation of insulated electrical wire 96 is thicker than the insulation of insulated electrical wire 94. The thinner insulation of insulated electrical wire 94 is generally more difficult to mechanically strip than the insulation of insulated electrical wire 96.

[0086] The insulating material of the insulated electrical wires 94 may be formed from any suitable material, such as, but not limited to, high temperature polyurethane. The insulating material of the insulated electrical wires 96 may be formed from, but not limited to, high temperature polyimide.

[0087] To facilitate easy connection of the insulated electrical wire 94 to the contact array 64 ( FIG. 9 ), the insulated electrical wire 94 includes an electrical insulating material 100 (only some of which are labeled for simplicity), configured to have a temperature rating of 150-200° C. so that the electrical insulating material 100 will not melt or degrade (e.g., carbonize and embrittle) during soldering of the insulated electrical wire 94 to the contact array 64 (e.g., at a temperature of 300° C.), thus eliminating the need for mechanical stripping of the insulation on the insulated electrical wire 94. The electrical insulating material 100 is more difficult to remove than thicker insulation on the insulated electrical wire 96, when the insulation on the insulated electrical wire 96 is actually thicker. In some embodiments, the insulated electrical wire 96 also includes an electrical insulating material 100 configured to have a temperature rating of 150-200° C. so that the electrical insulating material 100 will melt during soldering of the insulated electrical wire 96 to the contact array 64.

[0088] 18-20, the insulated electrical wire 96 includes an electrically insulating material 102 configured with a temperature rating of greater than 200 degrees Celsius to prevent melting or degradation (e.g., carbonization and embrittlement) of the electrically insulating material 102 during manufacture and / or use of the catheter 12. The electrically insulating material 102 is typically mechanically stripped away prior to soldering the insulated electrical wire 96 to the surface-mountable electrode 38, as described in more detail below.

[0089] Reference is now made to Figure 18, which is a schematic longitudinal cross-sectional view of an alternative flexible polymer circuit strip 24B for use in the catheter 12 of Figure 2. In some embodiments, the flexible polymer circuit strip 24 described above with reference to Figures 2-15 may be replaced with flexible polymer circuit strip 24B. Flexible polymer circuit strip 24B is substantially the same as flexible polymer circuit strip 24, except for the differences described herein below.

[0090] Figure 18 shows that the flexible polymer circuit strip 24B includes a plurality of strip electrodes 26, a contact array 64 disposed at the proximal end of the flexible polymer circuit strip 24B, a plurality of circuit traces 66 (shown more clearly in Figures 9 and 10) electrically connecting the plurality of strip electrodes 26 to the contact array 64, and an elongated resilient support element 50. Thus, when the flexible polymer circuit strip 24B is replaced with the flexible polymer circuit strip 24, the catheter 12 (FIG. 1) includes each flexible polymer circuit strip 24B including: a respective plurality of strip electrodes 26 (i.e., a plurality of strip electrodes 26 per flexible polymer circuit strip 24B), a respective contact array 64 disposed at the respective proximal end (i.e., one contact array 64 disposed at the proximal end of each flexible polymer circuit strip 24B), and a respective plurality of circuit traces 66 electrically connecting each of the plurality of strip electrodes 26 to the respective contact array 64 (i.e., the circuit traces 66 of each flexible polymer circuit strip 24B electrically connect the contact array 64 to the strip electrodes 26 of that flexible polymer circuit strip 24B).

[0091] The catheter 12 also includes surface-mountable electrodes 38 that are attached and configured such that each electrode 38 appears to overhang a respective one of the flexible polymer circuit strips 24B. That is, each electrode 38 is arranged in such a manner that the flexible circuit strips 24B are inserted into the hollow body portion such that the electrode 38 appears to overhang or protrude from the strips 24B, as seen in FIGS. 7A and 11 . For example, each of the flexible polymer circuit strips 24B may include one of the surface-mountable electrodes 38 attached thereto. As used herein, the terms “overhang,” “overhanging,” “protruding,” “protruding,” “intervening,” or “intervening” are used interchangeably to refer to the physical configuration of a larger electrode 38 that is disposed relative to a smaller strip 24B that extends through the larger electrode 38 along the central axis of the electrode 38, such that the larger electrode 38 appears to overhang the strip 24B.

[0092] Each group of insulated electrical wires 94 is electrically connected to a respective contact array 64 of each of the flexible polymer circuit strips 24B. Figure 18 shows one group of insulated electrical wires 94 electrically connected to the flexible polymer circuit strips 24B of Figure 18. Each of the insulated electrical wires 96 extends outside of each of the flexible polymer circuit strips 24B and is electrically connected to a respective surface-mountable electrode 38. Figure 18 shows one of the insulated electrical wires 96 extending outside of the flexible polymer circuit strip 24B below the elongated resilient support element 50 and electrically connected to a surface-mountable electrode 38.

[0093] The flexible polymer circuit strips 24B are covered with coverings 56, e.g., respective shrink sleeves formed from any suitable material, such as PET shrink tubing. The coverings 56 (e.g., shrink sleeves) secure each of the insulated electrical wires 96 to each of the flexible polymer circuit strips 24B. FIG. 18 shows one of the insulated electrical wires 96 secured to the flexible polymer circuit strips 24B via an elongated, resilient support element 50. The coverings 56 are typically shrunk using heat. Therefore, the electrical insulation material 102 ( FIG. 17 ) of the insulated electrical wire 96 must be able to withstand the heat applied to the coverings 56. If the electrical insulation material 102 melts or deteriorates, the conductors in the insulated electrical wire 96 may short to the elongated, resilient support element 50, which may be formed from a metal such as Nitinol. A window (not shown) is cut in the covering 56 over the strip electrodes 26 and the contact array 64. FIG. 18 shows the covering 56 before the window is cut. For simplicity, FIG. 18 does not show the coverings 56 on the ends of the flexible polymer circuit strip 24B and the elongated resilient support elements 50.

[0094] 18 are attached to the exterior of a covering portion 56 (e.g., a shrink sleeve) of the flexible polymer circuit strip 24B. Generally, each of the surface-mountable electrodes 38 is attached to the exterior of a respective covering portion 56 (e.g., a shrink sleeve) of the flexible polymer circuit strip 24B. The surface-mountable electrodes 38 may be attached to the flexible polymer circuit strip 24B using a pressure fit and / or using a suitable adhesive and / or other fastening method.

[0095] The insulated electrical wire 96 exits the sheath 56 through a hole 104 in the sheath 56. The distal end of the insulated electrical wire 96 is manually stripped (e.g., using a suitable mechanical wire stripper) and soldered to the surface-mountable electrode 38.

[0096] The manufacture of the cable 92 and flexible polymer circuit strip 24B is described in more detail with reference to FIGS.

[0097] Reference is now made to Figure 19, which is a flow chart 200 including steps in a method of manufacturing a catheter including the flexible polymer circuit strip 24B of Figure 18. Reference is also made to Figures 17 and 18.

[0098] The method includes forming or providing a catheter including a deflectable element 16 (FIG. 1), a proximal connector 20 (FIG. 1) connected to a distal end of the elongated deflectable element 16, and an expandable assembly 22 (FIG. 1) including flexible polymer circuit strips 24B. The flexible polymer circuit strips 24B have respective proximal ends connected to the proximal connector 20 and disposed circumferentially around the proximal connector. Each of the flexible polymer circuit strips 24B includes a respective plurality of strip electrodes 26, a respective contact array 64 disposed at the respective proximal end, and a respective plurality of circuit traces 66 electrically connecting each of the plurality of strip electrodes 26 with the respective contact array 66. The formation of the flexible polymer circuit strips 24B is described in more detail below.

[0099] It should be noted that the steps listed below with reference to Figures 19 and 20 may be performed in any suitable order, and not just the order described below. The method includes forming flexible polymer circuit strips 24B from layers (block 202), as described above with reference to Figures 9 and 10. The method also includes extending each of the insulated electrical wires 96 outside of each flexible polymer circuit strip 24B (block 206) and shrink-wrapping each of the insulated electrical wires 96 around each of the flexible polymer circuit strips 24B (block 208). This process is generally performed in two stages, as will be described in more detail with reference to Figure 20. The method may also include cutting windows in the covering portion 56 (e.g., a shrink sleeve) for the strip electrodes 26 and the contact array 64.

[0100] The method includes electrically connecting (block 210) each group of insulated electrical wires 94 to each respective contact array 64 of flexible polymer circuit strip 24B (e.g., using soldering). The electrical connecting step of block 210 may also include melting or degrading (e.g., from the heat of the soldering process) the electrical insulating material 100 of insulated electrical wires 94 in the areas where the insulated electrical wires 94 join to the contact arrays 64.

[0101] The method also includes attaching a surface-mountable electrode 38 onto each of the flexible polymer circuit strips 24B (block 212) to overhang the surface-mountable electrode 38 onto each of the flexible polymer circuit strips 24B. The step of block 212 may also include sliding the surface-mountable electrode 38 over a covering portion 56 (e.g., a shrink sleeve) of each of the flexible polymer circuit strips 24B.

[0102] The method also includes electrically connecting (e.g., using soldering) each of the insulated electrical wires 96 to each of the surface-mountable electrodes 38 (block 214). The step of block 214 may include mechanically stripping the electrical insulation material 102 at the distal ends of the insulated electrical wires 96 prior to electrically coupling the insulated electrical wires 96 to the surface-mountable electrodes 38.

[0103] The method also includes disposing each group of insulated electrical wires 94 and each group of insulated electrical wires 96 in each cable jacket 98 of each cable 92 (block 216). The step of block 216 may include disposing each of the insulated electrical wires 96 (i.e., one insulated electrical wire 96 per cable jacket 98) in each of the cable jackets 98 around each group of insulated electrical wires 94 (i.e., multiple insulated electrical wires 94 per cable jacket 98). In some embodiments, the insulated electrical wires 94 and insulated electrical wires 96 are grouped according to connection with the flexible polymer circuit strips 24B, such that if the catheter 12 includes eight flexible polymer circuit strips 24B, the catheter 12 also includes eight corresponding cables 92 with cable jackets 98. The cable jackets 98 may be formed by extruding a tube (e.g., PFA) over each wire bundle.

[0104] The method also includes disposing (block 218) insulated electrical wire 94 and insulated electrical wire 96 (which may be disposed within cable jacket 98 of cable 92) within lumen 60 (Figure 16) of deflectable element 16 (Figure 16).

[0105] Reference is now made to FIG. 20, which is a flow chart 300 containing more detailed steps in a method of manufacturing a catheter including the flexible polymer circuit strip 24B of FIG.

[0106] The method includes disposing (block 302) a respective covering 56 (e.g., a shrink sleeve) around each of the insulated electrical wires 96 and the flexible polymer circuit strips 24B. Each covering 56 typically covers all sides of each flexible polymer circuit strip 24B, including each elongated resilient support element 50.

[0107] The method includes forming holes 104 in the covering 56 (proximate where each surface-mountable electrode 38 is disposed on each flexible polymer circuit strip 24B) and pulling (block 304) the distal ends of each of the insulated electrical wires 96 through the respective holes 104 in the respective covering 56 (e.g., shrink sleeve). The method also includes heat-shrinking (block 306) the distal portions of each of the coverings 56 (e.g., shrink sleeve) (i.e., distal to the holes 104).

[0108] The method includes sliding each of the surface-mountable electrodes 38 over a respective heat-shrunk distal portion of the covering 56 (e.g., a shrink sleeve) (block 308) and electrically connecting the distal end of each of the insulated electrical wires 96 to each of the surface-mountable electrodes 38 (block 310).

[0109] The method also includes removing slack in each of the insulated electrical wires 96 (block 312), for example, by pulling on the proximal end of the insulated electrical wire 96. The method also includes heat shrinking (block 314) a proximal portion (i.e., proximal to the hole 104) of each of the coverings 56 (e.g., a shrink sleeve). The heat shrinking is performed in two stages, as described above, so that slack can be removed from the insulated electrical wires 96 after the surface-mountable electrodes 38 are attached to the distal ends of the heat-shrink coverings 56 and after the insulated electrical wires 96 are connected to the surface-mountable electrodes 38.

[0110] As used herein, the term "about" or "approximately" with respect to any numerical value or range of values ​​indicates a suitable dimensional tolerance that enables a portion of a component or a collection of components to function in accordance with its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value, for example, "about 90%" may refer to a range of values ​​of 72% to 108%.

[0111] Various features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.

[0112] The above-described embodiments are cited by way of example, and the present invention is not limited to what has been particularly shown and described in the foregoing specification. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described in the foregoing specification, as well as variations and modifications thereof not disclosed in the prior art that would occur to one skilled in the art upon reading the foregoing description.

[0113] [Embodiment] (1) A medical system including a catheter configured to be inserted into a body part of a living subject, the catheter comprising: an elongated deflectable element including a distal end; a proximal connector connected to the distal end; an expandable assembly comprising a plurality of flexible polymer circuit strips, the flexible polymer circuit strips having respective proximal ends connected to the proximal connector and disposed circumferentially around the proximal connector, each of the flexible polymer circuit strips including a respective plurality of strip electrodes, a respective contact array disposed at the respective proximal end, and a respective plurality of circuit traces electrically connecting the respective plurality of strip electrodes with the respective contact array; a plurality of surface-mountable electrodes attached to and overhanging each of said flexible polymer circuit strips. (2) The catheter first insulated electrical wires disposed within the elongated deflectable element, wherein each group of the first insulated electrical wires is electrically connected to the respective contact arrays of each of the flexible polymer circuit strips; 2. The system of claim 1, further comprising: second insulated electrical wires disposed within the elongated flexible element, each of the second insulated electrical wires extending outside of each of the flexible polymer circuit strips and electrically connected to each of the surface-mountable electrodes. (3) the first insulated electrical wire comprises an electrically insulating material configured to have a temperature rating of 150 to 200 degrees Celsius; 3. The system of claim 2, wherein the second insulated electrical wire comprises an electrically insulating material configured to have a temperature rating of greater than 200 degrees Celsius. (4) each of the first insulated electrical wires has a first wire gauge; each of the second insulated electrical wires having a second wire gauge; 4. The system of claim 3, wherein the first wire gauge is larger than the second wire gauge. (5) The system of embodiment 3, wherein the catheter includes a respective shrink sleeve securing each of the second wires to each of the flexible polymer circuit strips.

[0114] (6) The system of embodiment 5, wherein each of the surface-mountable electrodes is attached to the exterior of the respective shrink sleeve of each of the flexible polymer circuit strips. (7) the catheter includes respective cable jackets disposed within the elongated deflectable elements; the respective groups of first insulated electrical wires are disposed within the respective cable jackets; 3. The system of claim 2, wherein each of the second insulated electrical wires is disposed within each of the cable jackets, surrounded by the respective groups of the first insulated wires. (8) The system of claim 1, wherein each of the surface-mountable electrodes extends around the periphery of the respective flexible polymer circuit strip. (9) an ablation power generator connected to the catheter and configured to apply an electrical signal to at least one of the surface-mountable electrodes to ablate tissue at the body region; The system of embodiment 1, further comprising a mapping module configured to receive electrical signals from the strip electrodes of the flexible polymer circuit strip and generate an electroanatomical map in response to the received electrical signals. (10) The catheter includes a pusher including a distal portion and configured to advance and retract through the deflectable element; the catheter includes a distal coupling connected to the distal portion of the pusher; the flexible polymer circuit strip is circumferentially disposed around the distal portion of the pusher; the flexible polymer circuit strips having respective distal ends connected to the distal connectors; 2. The system of claim 1, wherein the strip is configured to bend radially outward when the pusher is retracted, expanding the expandable assembly from a collapsed configuration to an expanded configuration.

[0115] (11) A catheter device configured to be inserted into a body part of a living subject, the catheter device comprising: an elongated deflectable element including a distal end; a distal tip assembly disposed at the distal tip, the distal tip assembly comprising a plurality of first electrodes and a plurality of second electrodes; first insulated electrical wires disposed within the elongated deflectable element, each of the first insulated electrical wires electrically connected to a respective one of the first electrodes, the first insulated electrical wires comprising an electrically insulating material configured to have a temperature rating of 150 to 200 degrees Celsius; and second insulated electrical wires disposed within the elongated deflectable element, each second insulated electrical wire electrically connected to a respective second electrode, the second insulated electrical wires comprising an electrically insulating material configured to have a temperature rating of greater than 200 degrees Celsius. (12) The device of embodiment 11, further comprising a shrink sleeve covering at least a portion of the second insulated electrical wire. (13) A method for manufacturing a catheter, comprising: providing a catheter comprising: an expandable assembly including an elongated deflectable element; a proximal connector connected to a distal end of the elongated deflectable element; and a plurality of flexible polymer circuit strips having respective proximal ends connected to the proximal connector and disposed circumferentially around the proximal connector, each of the flexible polymer circuit strips including a respective plurality of strip electrodes, a respective contact array disposed at the respective proximal end, and a respective plurality of circuit traces electrically connecting the respective plurality of strip electrodes with the respective contact array; and attaching a plurality of surface-mountable electrodes onto each of the flexible polymer circuit strips, the surface-mountable electrodes overhanging the respective flexible polymer circuit strips. (14) disposing a first insulated electrical wire within the elongated deflectable element; electrically connecting respective groups of the first insulated electrical wires to the respective arrays of contacts of each of the flexible polymer circuit strips; disposing a second insulated electrical wire within the elongated deflectable element; extending each of the second insulated electrical wires outside of each of the flexible polymer circuit strips; 14. The method of claim 13, further comprising electrically connecting each of the second insulated electrical wires to each of the surface-mountable electrodes. (15) The electrically connecting each group of the first insulated electrical wires includes melting an electrical insulating material of the first wires; 15. The method of claim 14, wherein electrically connecting each of the second insulated electrical wires comprises mechanically stripping the electrical insulation material of the second insulated electrical wires.

[0116] (16) Each of the first insulated electrical wires has a first wire gauge; each of the second insulated electrical wires having a second wire gauge; 16. The method of claim 15, wherein the first wire gauge is larger than the second wire gauge. 17. The method of claim 15, further comprising shrink-wrapping each of the second insulated electrical wires onto each of the flexible polymer circuit strips. (18) disposing a respective shrink sleeve around each of the second insulated electrical wires and each of the flexible polymer circuit strips; Pulling each of the second insulated electrical wires through a respective hole in each of the shrink sleeves; heat shrinking respective distal portions of each of the shrink sleeves; sliding each of the surface-mountable electrodes onto the respective heat-shrunk distal portions of the shrink sleeves; electrically connecting each of the second insulated electrical wires to each of the surface-mountable electrodes; removing slack in each of the second insulated electrical wires; 18. The method of claim 17, further comprising heat shrinking each proximal portion of each of the shrink sleeves. (19) disposing said respective groups of said first insulated electrical wires within respective cable jackets; 15. The method of claim 14, further comprising disposing each of the second insulated electrical wires within each of the cable jackets surrounded by the respective groups of the first insulated wires.

Claims

1. 1. A medical system including a catheter configured to be inserted into a body site of a living subject, the catheter comprising: an elongated deflectable element including a distal end; a proximal connector connected to the distal end; an expandable assembly comprising a plurality of flexible polymer circuit strips, the flexible polymer circuit strips having respective proximal ends connected to the proximal connector and disposed circumferentially around the proximal connector, each of the flexible polymer circuit strips including a respective plurality of strip electrodes, a respective contact array disposed at the respective proximal end, and a respective plurality of circuit traces electrically connecting the respective plurality of strip electrodes with the respective contact array; a plurality of surface-mountable electrodes attached to and overhanging each of the flexible polymer circuit strips; The catheter first insulated electrical wires disposed within the elongated deflectable element, wherein respective groups of the first insulated electrical wires are electrically connected to the respective contact arrays of each of the flexible polymer circuit strips; a plurality of second insulated electrical wires extending from within the elongated flexible element to an exterior of each of the flexible polymer circuit strips, the second insulated electrical wires being electrically connected to each of the surface-mountable electrodes; the first insulated electrical wire comprises an electrically insulating material configured to have a temperature rating of 150 to 200 degrees Celsius; the second insulated electrical wire comprises an electrically insulating material configured with a temperature rating of greater than 200 degrees Celsius; the catheter including a respective shrink sleeve securing each of the second insulated electrical wires to each of the flexible polymer circuit strips; A medical system wherein each of the surface-mountable electrodes is attached to the exterior of the respective shrink sleeve of each of the flexible polymer circuit strips.

2. each of the first insulated electrical wires having a first wire gauge; each of the second insulated electrical wires having a second wire gauge; The system of claim 1 , wherein the first wire gauge is larger than the second wire gauge.

3. A medical system including a catheter configured to be inserted into a body part of a living subject, the catheter comprising: an elongated deflectable element including a distal end; a proximal connector connected to the distal end; an expandable assembly comprising a plurality of flexible polymer circuit strips, the flexible polymer circuit strips having respective proximal ends connected to the proximal connector and disposed circumferentially around the proximal connector, each of the flexible polymer circuit strips including a respective plurality of strip electrodes, a respective contact array disposed at the respective proximal end, and a respective plurality of circuit traces electrically connecting the respective plurality of strip electrodes with the respective contact array; a plurality of surface-mountable electrodes attached to and overhanging each of the flexible polymer circuit strips; The catheter first insulated electrical wires disposed within the elongated deflectable element, wherein respective groups of the first insulated electrical wires are electrically connected to the respective contact arrays of each of the flexible polymer circuit strips; a plurality of second insulated electrical wires extending from within the elongated flexible element to an exterior of each of the flexible polymer circuit strips, the second insulated electrical wires being electrically connected to each of the surface-mountable electrodes; the catheter including respective cable jackets disposed within the elongated deflectable elements; the respective groups of the first insulated electrical wires are disposed within the respective cable jackets; wherein each of the second insulated electrical wires is disposed within each of the cable jackets surrounded by the respective group of first insulated electrical wires.

4. The system of claim 1 , wherein each of the surface-mountable electrodes extends around the periphery of the respective flexible polymer circuit strip.

5. an ablation power generator connected to the catheter and configured to apply an electrical signal to at least one of the surface-mountable electrodes to ablate tissue at the body region; 10. The system of claim 1, further comprising: a mapping module configured to receive electrical signals from ones of the strip electrodes of the flexible polymer circuit strip and to generate an electroanatomical map in response to the received electrical signals.

6. the catheter includes a pusher including a distal portion and configured to advance and retract through the deflectable element; the catheter includes a distal coupling connected to the distal portion of the pusher; the flexible polymer circuit strip is circumferentially disposed around the distal portion of the pusher; the flexible polymer circuit strips having respective distal ends connected to the distal connectors; 10. The system of claim 1, wherein the flexible polymer circuit strip is configured to bow radially outward when the pusher is retracted to expand the expandable assembly from a collapsed configuration to an expanded configuration.

7. A method for manufacturing a catheter, comprising: providing a catheter comprising: an expandable assembly including an elongated deflectable element; a proximal connector connected to a distal end of the elongated deflectable element; and a plurality of flexible polymer circuit strips having respective proximal ends connected to the proximal connector and disposed circumferentially around the proximal connector, each of the flexible polymer circuit strips including a respective plurality of strip electrodes, a respective contact array disposed at the respective proximal end, and a respective plurality of circuit traces electrically connecting the respective plurality of strip electrodes with the respective contact array; attaching a plurality of surface-mountable electrodes onto each of the flexible polymer circuit strips, the surface-mountable electrodes overhanging the respective flexible polymer circuit strips; disposing a first insulated electrical wire within the elongated deflectable element; electrically connecting respective groups of the first insulated electrical wires to the respective arrays of contacts on each of the flexible polymer circuit strips; disposing a second insulated electrical wire within the elongated deflectable element; extending each of the second insulated electrical wires outside of each of the flexible polymer circuit strips; electrically connecting each of the second insulated electrical wires to each of the surface-mountable electrodes; the electrically connecting each group of the first insulated electrical wires includes melting an electrical insulating material of the first insulated electrical wires; the electrically connecting each of the second insulated electrical wires includes mechanically stripping electrical insulation material of the second insulated electrical wires; disposing a respective shrink sleeve around each of the second insulated electrical wires and each of the flexible polymer circuit strips; Pulling each of the second insulated electrical wires through a respective hole in each of the shrink sleeves; heat shrinking respective distal portions of each of the shrink sleeves; sliding each of the surface-mountable electrodes onto the respective heat-shrunk distal portions of the shrink sleeves; electrically connecting each of the second insulated electrical wires to each of the surface-mountable electrodes; removing slack in each of the second insulated electrical wires; and heat shrinking each proximal portion of each of the shrink sleeves.

8. each of the first insulated electrical wires having a first wire gauge; each of the second insulated electrical wires having a second wire gauge; The method of claim 7 wherein the first wire gauge is larger than the second wire gauge.

9. disposing said respective groups of said first insulated electrical wires within respective cable jackets; 8. The method of claim 7, further comprising disposing each of the second insulated electrical wires within each of the cable jackets surrounded by the respective group of the first insulated electrical wires.

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