Flexible high-density mapping and ablation catheter tips

Abstract

This disclosure relates to electrophysiology catheters. The catheters include a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis and a flexible tip portion extending from the distal end of the catheter shaft. In some aspects, the flexible tip portion comprises at least one flexible framework comprising a plurality of electrode-carrying arms, wherein each electrode-carrying arm extends from a distal end of the catheter shaft, wherein each of the plurality of electrode-carrying arms converges with at least one other of the plurality of electrode-carrying arms at a distal end of the at least one flexible framework; a plurality of electrodes coupled to the electrode-carrying arms; wherein each of the plurality of electrode-carrying arms comprises a shape memory material to predispose the at least one flexible framework into a plane, wherein at least a portion of the plane of the at least one flexible framework is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration.

Description

PATENT Atorney Docket No.: 108606-019010PC-1535096Client Reference No.: 15836WOO1 FLEXIBLE HIGH-DENSITY MAPPINGAND ABLATION CATHETER TIPSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 63 / 762,325 filed February 24, 2025, the full disclosure of which is incorporated herein by reference in its entirety for all purposes.BACKGROUND OF THE INVENTION

[0002] Heart rhythm disorders are very common in the United States, and are significant causes of morbidity, lost days from work, and death. Heart rhythm disorders exist in many forms, including atrial fibrillation (AF), ventricular tachycardia (VT), ventricular fibrillation (VF), supraventricular tachycardia (SVT), atrial tachycardia (AT), atrial flutter (AFL), premature atrial complexes / beats (PAC, APC) and premature ventricular complexes / beats (PVC). Definitive diagnosis and / or therapeutic medical procedures have often been performed using electrode-bearing catheters (electrophysiology catheters) placed within the heart chambers and / or vasculature.

[0003] Electrophysiology catheters carry one or more electrodes which may be used for mapping, ablation, diagnosis, or other therapies and / or treatments. Electrodes have been positioned along a catheter shaft or flexible arm elements in an attempt to analyze or map the electrical activity within a heart chamber and / or to contact heart tissue for therapy. Mapping typically involves the use or formation of external (patches on skin) electrograms and internal (catheters with electrodes) electrograms. A typical electrocardiogram of the cardiac cycle (heartbeat) consists of a P wave, a QRS complex and a T wave. During normal atrial depolarization, the main electrical vector is directed from the SA (sinoatrial) node, and spreads from the right atrium to the left atrium. Atrial depolarization is represented by the P wave on the electrocardiogram. The QRS complex reflects the rapid depolarization of the right and left ventricles. The T wave represents the repolarization (or recovery) of theventricles.

[0004] It is important to provide a complete and stable map of the electrical activity within a heart chamber (recording electrograms). In particular, in order to map electrical activity in certain portions of the right atrium and the left atrium (e.g. atrial septum, region of right pulmonary veins) devices must adequately conform to the irregular shape of the atria, as well as any contoured or trabeculated surfaces. The beating of the heart, especially if erratic or irregular, complicates matters, making it difficult to keep adequate contact between electrodes and tissue for a sufficient length of time. In order to provide dimensionally and spatially stable and complete electrograms, movement of the devices during a heartbeat must be minimized, retaining electrode contact with the heart tissue. Cardiac mapping catheters need to be capable of providing improved and dimensionally and / or spatially stable signals for diagnosis, and more complete coverage of the heart tissue, typically in the form of electrograms. Such devices are described in EP 2995250B1, EP 3738509B1, US 10,857,349B and EP 3679861 A, which are incorporated herein by reference in their entirety for all purposes.

[0005] Typically in a procedure, a catheter is manipulated through a patient’s vasculature to, for example, a patient’s heart. To position a catheter at a desired site within the body, some type of articulation may be used, such as using mechanical steering features incorporated into the catheter (or an introducer). In some examples, medical personnel may manually manipulate and / or operate the catheter using the mechanical steering features. In order to facilitate the advancement of catheters through a patient’s vasculature, a navigating system may be used. Such navigating systems may include, for example, electric-field-based and magnetic-field based positioning and navigating systems that are able to determine the position and orientation of the catheter (and similar devices) within the body and map features of the body. Various therapies can be delivered by the catheter to tissue with varied shapes and sizes. To better accommodate variations in heart anatomy and tissue configurations and to provide sufficient contact with the tissue for therapy, it can be important to have multiple electrodes coupled with a flexible tip portion and / or flexible arm elements to map the tissue and / or to contact the tissue for therapy.BRIEF SUMMARY OF THE INVENTION

[0006] Current high-density mapping and ablation catheters with flexible frameworks in a planar array can be used in a sweeping or “painting” motion across the cardiac tissue surface to place the planar array in contact with tissue and attain mapping data. However, a catheterhaving a planar flexible framework capable of “push” handling with minimal manipulation would be desirable. Other modifications to mapping and ablation catheters capable of “push” handling would also be desirable including i) the ability to isolate mapping electrodes from larger ablation electrodes, ii) improved maneuverability and reach of the catheter, and iii) the ability to select mapping and ablation electrode configurations, as well as improvements to manufacturing yields. The present invention seeks to provide a solution.

[0007] The present application relates to systems and apparatuses for catheter-based cardiac electrophysiology mapping and therapy. In particular, the present disclosure relates to high-density mapping catheter tips and to map-ablate catheter tips for diagnosing and treating cardiac arrhythmias via, for example, radiofrequency (RF) or pulsed field ablation (PF A). In particular, the present disclosure relates to flexible high-density mapping catheter tips, and to flexible ablation catheter tips that also have onboard high-density mapping electrodes.First and second aspects

[0008] According to a first aspect of the invention, there is provided a catheter comprising: a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis and a flexible tip portion extending distally from the distal end of the catheter shaft. The flexible tip portion comprises a flexible framework comprising a plurality of electrode-carrying arms, wherein each electrode-carrying arm extends from a distal end of the catheter shaft, wherein each of the plurality of electrode-carrying arms converges with at least one other of the plurality of electrode-carrying arms at a distal end of the flexible framework, and a plurality of electrodes coupled to the electrode-carrying arms. Each of the plurality of electrode-carrying arms comprises a shape memory material to predispose the flexible framework into a plane, wherein at least a portion of the plane of the flexible framework is disposed at an angle in the range of from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration. The angle is measured on the proximal side of the flexible framework. That is, the angle is between the plane of the flexible framework and the catheter shaft.

[0009] The plane of the flexible framework may be disposed at the angle in the range of from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration. That is, the whole flexible framework plane may be disposed at 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration and the plurality of electrodes coupled to the electrode-carrying arms form a flexible, planar array ofelectrodes. Alternatively, a portion of the plane of the flexible framework may be disposed at an angle in the range of from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration. Specifically, a distal portion of the flexible framework may be disposed at an angle in the range of from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration and a proximal portion of the flexible framework may be disposed substantially parallel to the longitudinal axis of the catheter shaft in a deployed configuration such that the plane of the flexible framework comprises a bend.

[0010] The flexible tip portion may extend distally from the distal end of the catheter shaft. A proximal coupler may be located at the distal end of the catheter shaft. The plurality of electrode-carrying arms may extend distally from the proximal coupler. Proximal ends of the electrode-carrying arms may extend proximally through the proximal coupler and into the distal end of the catheter shaft.

[0011] According to a second aspect of the invention, there is provided a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis and a flexible tip portion. The flexible tip portion comprising a flexible framework comprising a plurality of electrode-carrying arms, wherein each of the plurality of electrode-carrying arms converges with at least one other of the plurality of electrodecarrying arm at a distal end of the flexible framework, wherein each of the plurality of electrode-carrying arms comprises a shape memory material to predispose the flexible framework into a plane, wherein the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration; and a plurality of electrodes coupled to the electrode-carrying arms. An intermediate portion is between the distal end of the catheter shaft and the flexible tip portion, the intermediate portion comprising a shape memory material predisposed into at least a partial loop disposed in a plane intersecting the catheter shaft longitudinal axis, and wherein the flexible framework is disposed at a distal end of the intermediate portion.

[0012] The at least partial loop of the intermediate portion may be disposed in a plane orthogonal to the catheter shaft longitudinal axis. Either a) each of the plurality of electrodecarrying arms may extend from a distal end of the catheter shaft and through the intermediate portion, such that each arm is predisposed into the at least a partial loop, or b) each of the plurality of electrode-carrying arms may extend from a distal end of the intermediate portion. The intermediate portion functions as a curved transition between the elongate catheter shaftand the planar flexible framework, where the plane of the flexible framework is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft.

[0013] In a second aspect of the invention, each of the plurality of electrode-carrying arms may comprise a shape memory material and each electrode-carrying arm extends from a distal end of the catheter shaft and through the intermediate portion. In this arrangement, a proximal portion of each arm will be predisposed into the at least a partial loop.

[0014] A proximal coupler may be located at the distal end of the catheter shaft. The plurality of electrode-carrying arms may extend distally from the proximal coupler and through the intermediate portion. Proximal ends of the electrode-carrying arms may extend proximally through the proximal coupler and into the distal end of the catheter shaft.Alternatively, a proximal coupler may be located at the distal end of the intermediate portion. The plurality of electrode-carrying arms extend distally from the proximal coupler at the distal end of the intermediate portion and / or from a distal end of the catheter shaft and through the proximal coupler at the distal end of the intermediate portion, such that each arm is predisposed into the at least a partial loop.Flexible framework

[0015] The flexible framework is predisposed into a plane. In a deployed configuration, the plane of the flexible framework may be disposed at an angle in a range from 80 to 130° to the longitudinal axis of the catheter shaft. That is, the whole flexible framework plane is at an angle in a range from 80 to 130° to the longitudinal axis of the catheter shaft. The plane forms a planar array of electrodes. The angle of the plane of the flexible framework means that, unlike standard grid arrays, the planar array of electrodes can be orthogonal to (or near orthogonal to) the longitudinal axis of the catheter shaft. This beneficially minimizes the initial deflection of the flexible tip portion needed to use the catheter with a “push” handling mechanism.

[0016] In a deployed configuration, the plane of the flexible framework is disposed at an angle in a range from 80 to 130° to the longitudinal axis of the catheter shaft. The plane of the flexible framework is predisposed at the angle without application of an external (e.g. manual) force. The plane of the flexible framework may be set orthogonal to the longitudinal axis of the catheter shaft. The plane of the flexible framework may be set at an angle of greater than 90° to the longitudinal axis of the catheter shaft. This advantageously allows for a reaction force upon contact of the flexible framework with tissue, to bring into anorthogonal position for mapping. The plane of the flexible framework may be set at an angle of less than 90° to the longitudinal axis of the catheter shaft, particularly from 80 to 90° to the longitudinal axis of the shaft. This advantageously can allow an increased number of electrodes to make contact with tissue. This may also give the operator visual feedback when tissue contact is made and allows for better recovery from reaction forces upon contact of the flexible framework with tissue.

[0017] Alternatively, the flexible framework may be predisposed into a plane which includes a bend such that a portion of the flexible framework is disposed substantially parallel to the longitudinal axis of the catheter shaft and a portion of the flexible framework is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration. The portion of the flexible framework is predisposed at the angle without application of an external (e.g. manual) force. A proximal portion of the flexible framework is disposed substantially parallel to the longitudinal axis of the catheter shaft and a distal portion of the flexible framework is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration. In a deployed configuration, the bent array of electrodes can be used in both a sweeping manner and with a “push” handling mechanism.

[0018] In accordance with a first aspect of the invention, the catheter may comprise one or more additional flexible frameworks. Each additional flexible framework may comprise a plurality of electrode-carrying arms, wherein each electrode-carrying arm extends from a distal end of the catheter shaft, wherein each of the plurality of electrode-carrying arm converges with at least one other of the plurality of electrode-carrying arms at a distal end of the flexible framework. A plurality of electrodes may be coupled to the electrode-carrying arms of the additional flexible framework and form a flexible, planar array of electrodes. Each of the plurality of electrode-carrying arms of the additional flexible frameworks may comprise a shape memory material to predispose the additional flexible framework into a plane, wherein the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration. The additional flexible frameworks may be distributed around the distal end of the catheter shaft. The additional flexible frameworks may be evenly distributed around the distal end of the catheter shaft, or alternatively, the additional flexible frameworks may be distributed around one side of the distal end of the catheter shaft. For example, there may be three flexible frameworks in total.Each flexible framework may extend from the distal end of the catheter shaft and a proximal portion of each flexible framework be spaced from one another by 90 degrees.

[0019] Alternatively, each flexible framework may be made of a single electrode-carrying arm which is bent to form a bent loop. That is, the framework does not comprise a plurality of arms which converge with each other. The single arm may be bent into a multi-bend loop, for example a D-shaped loop or a rectangular-shaped loop. The bend angles may be 80 to 130 degrees, optionally 90 degrees. The electrode-carrying arm of the flexible framework may comprise a shape memory material to predispose the bent loop flexible framework into a plane, wherein the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration. The at least one flexible framework may be distributed around the distal end of the catheter shaft. The additional flexible frameworks may be evenly distributed around the distal end of the catheter shaft, or alternatively, the additional flexible frameworks may be distributed around one side of the distal end of the catheter shaft. For example, there may be three flexible frameworks in total. Each flexible framework may extend from the distal end of the catheter shaft and be spaced from one another by 60 degrees.

[0020] Two flexible frameworks, each comprising a single electrode-carrying arm bent into a multi-bend loop, may be disposed opposite each other on either side of the distal end of the catheter shaft. The multi-bend may form a D-shaped loop or a rectangular-shaped loop. The bend angles may be 80 to 130 degrees, optionally 90 degrees. The two flexible frameworks may be arranged to form an H-shape or an I-shape flexible tip portion from the bent electrode-carrying arms. The electrodes can be arranged in a grid array on the H-shape or I-shape flexible tip portion. The grid array may allow for regular electrode spacing, for example in a 4 by 4 grid array, or an 8 by 2 grid array.

[0021] Multiple flexible frameworks, each with prescribed electrode spacing, allows more tissue to be mapped and / or ablated per each device placement. This can advantageously result in the fast and efficient production of high-density maps with resolution to identify the precise ablation location.Electrode-carrying arms

[0022] The total number of electrode-carrying arms is not limited. The flexible framework may comprise at least two electrode-carrying arms. The flexible framework may comprise at least four electrode-carrying arms, where the electrode-carrying arms may include a firstinboard arm, a second inboard arm, a first outboard arm, and a second outboard arm. One or more additional midboard arms may be included. There may be two, four, five, six or seven electrode-carrying arms.

[0023] The first and second inboard arms, the first and second outboard arms and further midboard arms may include proximal ends. The proximal ends may be disposed within a distal end of the catheter shaft.

[0024] Where each of the four electrode-carrying arm converges with at least one other of the plurality of electrode-carrying arm at a distal end of the flexible tip portion, a distal end of the first inboard arm may be connected with a distal end of the second inboard arm. A distal end of the first outboard arm may be connected with a distal end of the second outboard arm. The connected portion of the first and second inboard arms, and the first and second outboard arms may be coupled together at a distal end of the flexible tip portion.

[0025] A plurality of tubular polymeric members may be included in the flexible framework. Each tubular polymeric member may comprise a first open end and an opposed second open end defining an open lumen therebetween, the tubular polymeric member comprising an inner member surface and an outer member surface, wherein at least one of the plurality of electrode-carrying arms is at least partially disposed within the lumen of said tubular polymeric member.Electrodes

[0026] A plurality of electrodes are coupled to the electrode-carrying arms. “Coupled to” can encompass electrodes being “patterned” on to the electrode-carrying arms, “deposited” on to the electrode-carrying arms, “mounted on” the electrode-carrying arms or electrodes which are ring electrodes disposed around the electrode-carrying arms, or any other means of disposing the plurality of electrodes on the electrode-carrying arms.

[0027] The plurality of electrodes coupled to the electrode-carrying arms may form a flexible, planar array of electrodes. The plurality of electrodes may comprise a first array of electrodes patterned onto the plurality of electrode-carrying arms. A second array of electrodes may additionally be patterned onto the plurality of electrode-carrying arms. The first array and second array of electrodes may comprise a row of longitudinally-aligned electrodes aligned parallel to the electrode carrying arms. The first array may be arranged on a first side of the electrode-carrying arms. The second array may be arranged on a secondside of the electrode-carrying arms. The first side may be a top (distal-most) surface of the plane of the flexible framework and the second side may be a bottom (proximal-most) surface of the plane of the flexible framework.

[0028] The plurality of electrodes may be coupled to the plurality of electrode-carrying arms via a plating process. The plurality of electrodes may be arranged in a plurality of rows. Each row may be distributed along a different one of the plurality of electrode-carrying arms. The plurality of electrode-carrying arms of the flexible framework may be configured to maintain the plurality of electrodes in the plurality of rows in a spaced relationship such that each of the plurality of electrodes can capture separate data about the electrical activity of cardiac tissue adjacent to the plurality of electrodes.

[0029] The plurality of electrodes may be ring electrodes and / or spot electrodes. The electrodes may be all the same size. The electrodes may be different sizes. A distal-most electrode on one or more of the electrode-carrying arms may be slightly longer (enlarged) than the other electrodes. For example, the longer electrodes may have a length in a range from 125% to 300%, 150 to 250%, 175 to 225% or 190 to 210% of a length of the remaining electrodes. Where the electrodes comprise spot electrodes, multiple spot electrodes can be shorted together to act as a single, longer electrode.

[0030] The plurality of electrodes may be equally spaced along each of the plurality of electrode-carrying arms. The electrodes may be longitudinally separated from each other by approximately 0.20 to 5mm, 0.5 to 4mm, 1 to 3 mm, or by 1mm, 1.5mm, 2mm, 2.5mm, 3mm or 4mm (centre-to-centre distance). The electrodes may be longitudinally separated from each other by an edge-to-edge distance of approximately 0.20 to 4mm, 0.75 to 3mm, 1 to 2 mm. Smaller longitudinal spacing of the electrodes may be facilitated by using spot electrodes.

[0031] The plurality of electrodes may comprise between four and sixty-four individual electrodes, preferably 16 electrodes. Each electrode-carrying arm may comprise 3 to 8 electrodes, preferably 4 electrodes.

[0032] A plurality of conductive traces may be disposed on the flexible tip portion. Each of the plurality of conductive traces may be electrically coupled with a respective one of the plurality of electrodes. A mounting portion may be connected to the plurality of electrodecarrying arms, wherein the mounting portion includes a plurality of contact pads electrically coupled with the plurality of electrodes via the plurality of conductive traces. A nonconductive material, for example a dielectric material, may be disposed between each ofthe plurality of conductive traces and the flexible tip portion. The nonconductive material may cover an outer facing surface of each of the plurality of conductive traces. Each of the plurality of conductive traces may be aligned parallel to the axis of the respective electrodecarrying arm.

[0033] A plurality of flexible circuits may be disposed on the flexible tip portion. Each flexible circuit comprises a nonconductive material, for example a polymeric substrate, having an upper surface and an opposed lower surface, at least one of the plurality of electrodes disposed over at least part of the upper surface of the polymeric substrate, and one or more conductive traces. The conductive traces can be disposed over at least a portion of the lower surface of the polymeric substrate. In addition or alternatively, the conductive traces can be disposed over at least a portion of the upper surface of the polymeric substrate. In addition or alternatively, the conductive traces can be embedded within the polymeric substrate. The one or more conductive traces are in electrical communication with the electrodes.

[0034] The conductive traces may include one or more layers of any suitable conductive metal, including copper, a noble metal (e.g., gold, platinum, iridium), titanium and nickel. The electrical traces may include a copper layer with a gold layer on top to protect it from corrosion. The electrical traces may include a nickel layer in between copper and gold layers to retard the diffusion of the copper into the gold, thus reduce the corrosion protection offered by the gold. The electrical traces may include metal oxide layers. For example, the electrical traces may include a layer of platinum or iridium, which are subsequently oxidized to form platinum / iridium oxide to improve mapping performance. The electrical traces may include gold embedded within liquid crystal polymer.

[0035] The flexible circuit polymeric substrate may comprise an insulating material, preferably a dielectric material. The polymeric substrate may comprise a polyethylene terephthalate (PET) heat shrink material, polyurethane, nylon, parylene, a polyimide (e.g., PI-2771 or HD-4004 available from HD Microsystems, or KAPTON available from DuPont), a polyether block amide (such as Pebax®), and / or an epoxy (e.g., SU8 epoxy available from MicroChem Corp)). Preferably the insulating material is selected from polyurethane, nylon and a polyether block amide, more preferably a polyether block amide.

[0036] Each flexible circuit may include polyimide or liquid crystal polymer (LCP) to tolerate soldering temperatures. The flexible circuit may include glass. The flexible circuitmay include other polymers employed along with low temperature interconnect methods (e.g., solder jetting).

[0037] In the flexible circuit, the one or more conductive traces can be disposed over at least a portion of the lower surface of the polymeric substrate. Each flexible circuit may further comprise vias to provide electrical communication between the one or more conductive traces and the electrodes. Alternatively, metal plated holes may be used to provide electrical communication between the one or more conductive traces and the electrodes. A polymeric layer may be disposed between the lower surface of the polymeric substrate and the electrode-carrying arms, such as to provide electrical insulation between the traces and the arms. The polymeric layer may be adhesively and / or thermally secured to the surface each of the plurality of electrode-carrying arms. Alternatively, the polymeric layer may be adhesively and / or thermally secured to an outer member surface of the polymeric tubular member. The polymeric layer provides an extra layer of insulation.

[0038] The one or more conductive traces can be disposed at least a portion of the upper surface of the polymeric substrate. Each flexible circuit may further comprise a polymeric covering over the upper surface of the polymeric substrate and the conductive traces with the electrodes being substantially free of the polymeric covering. The polymeric covering may be bonded to the polymeric substrate with the use of suitable adhesive, usually acrylic adhesive. Preferably, the upper flexible circuit surface is substantially flat, i.e., the polymeric covering and the electrodes being substantially the same height. Alternatively, the electrodes may be raised slightly above the polymeric substrate surface. The electrodes may be raised with the use, for example, of strips of material disposed between the polymeric substrate and the electrodes. Alternatively, the electrodes may be depressed slightly below the polymeric substrate surface. The polymeric covering may comprise a similar material as the polymeric substrate, but different materials may suitably be used.

[0039] The lower surface of the polymeric substrate of the flexible circuit may be adhesively and / or thermally bonded to a surface of each of the electrode-carrying arms. Alternatively, the lower surface of the polymeric substrate of the first and / or second flexible circuit may be adhesively and / or thermally secured to an outer member surface of the polymeric tubular member. The polymeric substrate of the flexible circuit may be deposited on a portion of the surface of the electrode-carrying arm. For example, for a flattened or rectangular-cross-section electrode-carrying arm, the polymeric substrate may be depositedon a first surface or a second surface of the electrode-carrying arm. For example, for a cylindrical electrode-carrying arm, the polymeric substrate may be deposited on a portion of the curved circumference of the electrode-carrying arm. Alternatively, the polymeric substrate of the flexible circuit may be deposited on the entire surface of the electrodecarrying arm, surrounding the electrode-carrying arm.

[0040] The flexible circuit may be wrapped around the electrode-carrying arm, for example in a spiral shape around the arm.

[0041] Each flexible circuit may include an adhesive layer. The adhesive layer may include polyurethane, cyanoacrylate, polyvinyl acetate, acrylic, polyimide, epoxy, hot melt or fluoropolymer adhesives. Alternatively, each flexible circuit may not include an adhesive layer. Thermal bonding may include the application of heat and / or compressive pressure to the layers. The flexible circuit may also be directly printed onto the substantially planar flexible substrates as described in US Patent Nos. 10,595,738B2; US 11,039,773 B2; and US Publication No. 2024-0415558A1, the disclosures which are incorporated herein by reference in their entirety for all purposes.

[0042] The plurality of electrodes may be configured for use as mapping electrodes. The plurality of electrodes are useful to (1) define regional propagation maps on one centimeter square areas within the atrial walls of the heart; (2) identify complex fractionated atrial electrograms for ablation; (3) identify localized, focal potentials between the electrodes for higher electrogram resolution; and / or (4) more precisely target areas for ablation. These mapping catheters and ablation catheters are constructed to conform to, and remain in contact with, cardiac tissue despite potentially erratic cardiac motion. Such enhanced stability of the catheter on a heart wall during cardiac motion provides more accurate mapping and ablation due to sustained tissue-electrode contact. The catheters are suitable for RF ablation and Pulsed Field Ablation. Additionally, the catheters described herein may be useful for epicardial and / or endocardial use.

[0043] One or more of the plurality of electrodes could be used to send pacing signals to, for example, cardiac tissue.Third aspect

[0044] According to a third aspect of the invention, there is provided a catheter comprising: a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining acatheter shaft longitudinal axis and a flexible tip portion. The flexible tip portion comprises: a flexible framework comprising a substantially planar flexible substrate; a plurality of electrodes mounted on the flexible substrate; and a plurality of flexible struts coupled between the distal end of the catheter shaft and the flexible substrate, wherein each of the plurality of flexible struts comprises a shape memory material configured to hold the position of the substantially planar flexible substrate in a plane that is at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration.Flexible framework

[0045] The substantially planar flexible substrate of the flexible framework is predisposed into a plane. In a deployed configuration, the substantially planar flexible substrate is disposed in a plane that is at an angle in a range from 80 to 130° to the longitudinal axis of the catheter shaft. The substantially planar flexible substrate may be disposed in a plane that is set orthogonal to the longitudinal axis of the catheter shaft. The substantially planar flexible substrate may be disposed in a plane that is set at an angle of greater than 90° to the longitudinal axis of the catheter shaft. The substantially planar flexible substrate may be disposed in a plane that is set at an angle of less than 90° to the longitudinal axis of the catheter shaft, particularly from 80 to 90° to the longitudinal axis of the shaft.

[0046] The flexible tip portion may be adapted to conform to a tissue. That is, the flexible tip portion, including the substantially planar flexible substrate of the flexible framework can bend and flex to conform to a tissue in the deployed configuration. The substantially planar flexible substrate may have a degree of concave curvature when fully deployed. The substantially planar flexible substrate may have a much larger surface area than the crosssection of the catheter shaft as presented to tissue. The substantially planar flexible substrate may have a surface area of 5mm x 5mm to 30mm x 30mm, for example, 12mm x 12mm.

[0047] The substantially planar flexible substrate is configured to have an expanded state in a deployed configuration and a collapsed configuration. The substantially planar flexible substrate of the flexible framework may be folded or rolled in the collapsed configuration. The plurality of flexible struts may be folded or otherwise collapsed / compressed in the collapsed configuration. The flexible tip portion is configured to fold up or collapse into a smaller arrangement / configuration (collapsed configuration) to permit the flexible tip portion to fit into a desired size and / or shape.

[0048] The catheter is deliverable through and into bodily organs, such as but not limited to the heart. In preparation for insertion of the catheter, the flexible tip portion is compressed (folded or collapsed) to fit within the lumen of a delivery sheath (e.g. delivery catheter) or other similar delivery device. The compressed flexible tip portion may be an approximate or substantially elongate cylindrical shape. The flexible tip portion is deliverable through and past the distal end of the lumen of the delivery shaft. The flexible tip portion expands so that the flexible framework adopts its deployed configuration as it exits the distal end of the delivery sheath.

[0049] For example, the flexible tip portion can be in a first collapsed state, allowing the flexible tip portion to be stored for delivery. After the delivery sheath is maneuvered to the desired location (e.g., inside a heart) of the body the flexible tip portion can be expanded to a deployed configuration (e.g. an expanded state). The plurality of flexible struts can be used to "unfold" or expand the substantially planar flexible substrate from the collapsed configuration to the deployed configuration.

[0050] The substantially planar flexible substrate may be formed from a material comprising a polymer. The material may be selected from polyethylene terephthalate (PET), polyester, polyethylene, polyolefins (e.g. HDPE), poly(vinyl chloride), polyurethane, nylon, parylene, a polyimide (e.g., PI-2771 or HD-4004 available from HD Microsystems, or KAPTON available from DuPont), a polyether block amide (such as Pebax®), and / or an epoxy (e.g., SU8 epoxy available from MicroChem Corp)), or combinations thereof.

[0051] A proximal coupler may be located at the distal end of the catheter shaft. The plurality of flexible struts may extend distally from the proximal coupler. Proximal ends of the flexible struts may extend proximally through the proximal coupler and into the distal end of the catheter shaft.Flexible struts

[0052] The plurality of flexible struts may be coupled to at least a portion of the perimeter of the flexible substrate. The flexible struts may be coupled at the edges and / or the comers of the flexible substrate. The substantially planar flexible substrate may be any suitable shape, such as a circle, an ellipsoid, a quadrilateral-shape (including a rectangle or square shape). There may be at least four flexible struts, where at least one stmt may be coupled to each corner of the rectangular or square shape. The total number of flexible stmts is not limited. There may be two, four, five, six or more flexible stmts.

[0053] The plurality of flexible struts may be compressible. In particular, the plurality of flexible struts may each be axially compressible to allow for reaction to applied (e.g. external / manual) forces while maintaining the flexible framework in a plane at 80 to 130 degrees to the longitudinal axis of the shaft. That is, the struts may each bend and / or compress in response to the applied forces, or may absorb applied forces.

[0054] Each of the plurality of flexible struts may have a curved shape. The curved shape may include a wave shape or a multi-curve shape, such as a double-curve shape. The curved shape may be an S-shape. The curved strut shape can facilitate expansion of the substantially planar flexible substrate. Each flexible strut may form an angle with the longitudinal axis of the catheter shaft. For example, the proximal end of the flexible strut may form an angle (“expansion angle”) of about 30 to 60 degrees, 35 to 55 degrees or 40 to 50 degrees to the longitudinal axis of the catheter shaft. The expansion angle may be about 45 degrees to the longitudinal axis of the catheter shaft.

[0055] The length of each of the plurality of flexible struts may be between 10 to 30cm. Electrodes

[0056] A plurality of electrodes are mounted on the substantially planar flexible substrate and form a flexible, planar array of electrodes. “Mounted on” can encompass electrodes being “patterned” onto or within the substantially planar flexible substrate, “deposited” onto or within the substantially planar flexible substrate, or any other means of disposing the plurality of electrodes on the substantially planar flexible substrate.

[0057] The plurality of electrodes may comprise a first array of electrodes patterned onto the substantially planar flexible substrate. The first array of electrodes may be arranged in a grid configuration. The plurality of electrodes may comprise a second array of electrodes patterned onto the substantially planar flexible substrate. The second array of electrodes may be arranged in a grid configuration. The grid configuration may be a square, rectangular or tri- (triangular or 3 -sided polygon) shape grid. The grid configuration may comprise equally-spaced electrodes may be equally spaced. The electrodes may be separated from each other by approximately 0.20 to 5mm, 0.5 to 4mm, 1 to 3 mm, or by 1mm, 1.5mm, 2mm, 2.5mm, 3mm or 4mm (centre-to-centre distance). The electrodes may be separated from each other by an edge-to-edge distance of approximately 0.20 to 4mm, 0.75 to 3mm, 1 to 2 mm. The grid configuration may improve special fidelity and definition of displayed images of the heart(low to high voltage regions e.g., gaps in lesions or re-entrant circuit geometry of tissue) to improve targeting of ablation energy.

[0058] The substantially planar flexible substrate may comprise a top (distal-most) surface and a bottom (proximal-most) surface, the bottom surface being parallel with the top surface. The first array of electrodes may be patterned onto the top surface of the substantially planar flexible substrate. The second array of electrodes may be patterned onto the bottom surface of the substantially planar flexible substrate. The first array of electrodes may be aligned with the second array of electrodes (each electrode of the first array is positioned directly opposed to an electrode of the second array). This arrangement can be advantageous in assessing the contact at each tissue-facing electrode (e.g. of the first array of electrodes).

[0059] The plurality of electrodes may comprise between four and sixty-four individual electrodes. The electrodes may be all the same size. The electrodes may be different sizes. The electrodes may be spot electrodes, optionally multiple spot electrodes can be shorted together to act as a single, longer electrode.

[0060] A plurality of conductive traces may be disposed on the substantially planar flexible substrate. Each of the plurality of conductive traces may be electrically coupled with a respective one of the plurality of electrodes. A mounting portion may be connected to the substantially planar flexible substrate, wherein the mounting portion includes a plurality of contact pads electrically coupled with the plurality of electrodes via the plurality of conductive traces. A nonconductive material, for example a dielectric material, may be disposed between each of the plurality of conductive traces and the substantially planar flexible substrate. The nonconductive material may cover an outer facing surface of each of the plurality of conductive traces.

[0061] A plurality of flexible circuits may be disposed on the substantially planar flexible substrate. Each flexible circuit comprises at least one of the plurality of electrodes disposed over at least part of the top (distal-most) and / or bottom (proximal-most) surface of the substantially planar flexible substrate, and one or more conductive traces. The conductive traces can be disposed over at least a portion of the bottom (proximal-most) surface of the substantially planar flexible substrate. In addition or alternatively, the conductive traces can be embedded within the substantially planar flexible substrate. In addition or alternatively, the conductive traces can be disposed over at least a portion of the top (distal-most) surface ofthe substantially planar flexible substrate. The one or more conductive traces are in electrical communication with the electrodes.

[0062] The conductive traces may include one or more layers of any suitable conductive metal, including copper, a noble metal (e.g., gold, platinum, iridium), titanium and nickel, and alloys thereof. The conductive traces may include a copper layer with a gold layer on top to protect it from corrosion. The conductive traces may include a nickel layer in between a copper and gold layers to retard the diffusion of the copper into the gold, thus reduce the corrosion protection offered by the gold. Optional further layers of titanium may be included. The conductive traces may include metal oxide layers. For example, the conductive traces may include a layer of platinum or iridium, which are subsequently oxidized to form platinum / iridium oxide to improve mapping performance. The conductive traces may include doped polymers (“stretchy” conductors), such as gold embedded within a liquid crystal polymer or polymers doped with copper nanowires.

[0063] In the flexible circuit, the one or more conductive traces can be disposed over at least a portion of the bottom (proximal-facing) surface of the substantially planar flexible substrate. Each flexible circuit may further comprise vias to provide electrical communication between the one or more conductive traces on the bottom surface and electrodes on the top (distal-most surface). An additional polymeric layer may be disposed over the conductive traces on the bottom (proximal-most) surface, such as to provide electrical insulation. Any electrodes being substantially free of the additional polymeric layer.

[0064] The one or more conductive traces can be disposed at least a portion of the top (distal-most) surface of the substantially planar flexible substrate. Each flexible circuit may further comprise vias to provide electrical communication between the one or more conductive traces and electrodes on the bottom (proximal-most surface). Alternatively, metal plated holes may be used to provide electrical communication between the one or more conductive traces and the electrodes. An additional polymeric layer may be disposed over the conductive traces on the top (distal-most) surface, such as to provide electrical insulation. Any electrodes being substantially free of the additional polymeric layer.

[0065] Preferably, the flexible circuit surface is substantially flat, i.e., any polymeric covering and the electrodes being substantially the same height. Alternatively, the electrodes may protrude slightly above the polymeric substrate surface. The electrode surface may be raised with the use, for example, of strips of material disposed between the substantiallyplanar flexible substrate and the electrodes. Other ways of raising the electrode surface may be implemented. Alternatively, the electrodes may be depressed slightly below the substantially planar flexible substrate surface. The additional polymeric layer may comprise a similar material as the substantially planar flexible substrate, but different materials may suitably be used.

[0066] Each flexible circuit may include an adhesive layer. The adhesive layer may include polyurethane, cyanoacrylate, polyvinyl acetate, acrylic, polyimide, epoxy, hot melt or fluoropolymer adhesives. Alternatively, each flexible circuit may not include an adhesive layer. Thermal bonding may include the application of heat and / or compressive pressure to the layers. The flexible circuit may also be directly printed onto the substantially planar flexible substrates as described in US 10,595,738 B2 and US 11,039,773 B2.

[0067] One or more additional electrodes may be coupled to the plurality of flexible struts. The plurality of electrodes may be coupled to the plurality of flexible struts via a plating process. The plurality of electrodes on the plurality of flexible struts may be ring electrodes. The plurality of flexible struts may further comprise a plurality of conductive traces and / or a plurality of flexible circuits as described under the “Electrodes” section for the first and second aspects above. For example, a conductive trace may extend along the length of at least one of the plurality of flexible struts. At least one flexible circuit may be disposed on at least one of the plurality of flexible struts, for example a conductive trace may extend along the length of one of the flexible struts or a flexible circuit may be spirally wrapped around the length of one of the flexible struts.Fourth aspect

[0068] According to a fourth aspect of the invention, there is provided a catheter comprising: a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; and an expandable assembly. The expandable assembly comprises: a balloon member having a top surface, a bottom surface, and an interior cavity, each of the top surface and the bottom surface having an outer facing layer and an inner facing layer; a top flexible framework disposed between the outer facing layer and the inner facing layer of the top surface of the balloon member; a bottom flexible framework disposed between the outer facing layer and the inner facing layer of the bottom surface of the balloon member; a first plurality of electrodes patterned onto the top flexible framework; a second plurality of electrodes patterned onto the bottom flexible framework, wherein thefirst plurality of electrodes are aligned with the second plurality of electrodes; a plurality of conductive traces disposed on each of the flexible frameworks, each of the plurality of conductive traces electrically coupled with a respective one of the first plurality of electrodes and the second plurality of electrodes; and a flexible structural element disposed within the interior cavity. The expandable assembly comprises a first delivery configuration, a second deployed configuration, and an intermediate configuration between the first delivery configuration and the second deployed configuration. In the intermediate configuration, the balloon member is unconstrained from an introducer sheath and uninflated, and the balloon member has a substantially planar shape, and the flexible structural element comprises a shape memory material to predispose the balloon member in a plane at an angle in a range from 80 to 130 degrees to the longitudinal axis of the shaft.Expandable assembly

[0069] The balloon member is predisposed into a plane. In an intermediate configuration, the balloon member is predisposed in a plane at an angle in a range from at 80 to 130° to the longitudinal axis of the catheter shaft. The balloon member may be predisposed in a plane set orthogonal to the longitudinal axis of the catheter shaft. The balloon member may be predisposed in a plane at an angle of greater than 90° to the longitudinal axis of the catheter shaft. The balloon member may be predisposed in a plane at an angle of less than 90° to the longitudinal axis of the catheter shaft, particularly from 80 to 90° to the longitudinal axis of the shaft.

[0070] The flexible structural element may extend from the distal end of the catheter shaft and into the interior cavity. The flexible structural element may function as a bent or curved transition between the elongate catheter shaft and the balloon member disposed in a plane at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft. A portion of the flexible structural element between the distal end of the catheter shaft and the interior cavity may comprise an 80 to 130 degree bend. Alternatively, a portion of the flexible structural element between the distal end of the catheter shaft and the interior cavity may be predisposed into at least a partial loop disposed in a plane orthogonal to the catheter shaft longitudinal axis, such that the portion of the flexible structural element extending into the interior cavity of the balloon member positions the balloon member into a plane at an angle in a range from 80 to 130 degrees to the longitudinal axis of the shaft.

[0071] The top flexible framework and the bottom flexible framework may comprise a variety of materials including polyimide, thermoplastics, Pebax, polyurethanes, and like polymers. The bottom flexible framework may be the same (e.g., including the same size, shape, layout, etc.) and is associated with the same components as the top flexible framework. For example, electrodes disposed on each of the top flexible framework and the bottom flexible framework may be mirrored on the top surface and the bottom surface of the balloon member. Branches of the top flexible framework and the bottom flexible framework may mirror one another in a top view of the top flexible framework and the bottom flexible framework. Alternatively, the top flexible framework and the bottom flexible framework may not be the same shape, size, layout, etc. For example, electrodes disposed on each of the top flexible framework and the bottom flexible framework may not be mirrored on the top surface and the bottom surface of the balloon member. For example, branches of the top flexible framework and the bottom flexible framework may appear to interleave one another in a top view of the top flexible framework and the bottom flexible framework.

[0072] The flexible structural element is a shape memory material, preferably nitinol. The shape memory material element may be disposed between the top flexible framework and the bottom flexible framework. The shape memory material may be nitinol wire. The flexible structural element may be a looped element extending along the longitudinal axis (e.g., longitudinal axis) defined by the catheter shaft. Alternatively, the flexible structural element may have any configuration including extending along a perimeter of the balloon member, an internally flat shape (when viewed from a top perspective) substantially mirroring the perimeter of the balloon member, a pronged shape extending from the longitudinal axis, etc. The flexible structural element may comprise a plurality of arms, wherein each arm extends from a distal end of the catheter shaft, wherein each of the arms converges with at least one other of the arms at a distal end of the expandable assembly.

[0073] The flexible structural element may be configured to inflate (expand) the balloon member in the second deployed configuration. The nitinol of the flexible structural element may expand to expand the balloon member in the second deployed configuration.Alternatively, the balloon member may remain in a non-expanded / non-inflated configuration during use. In this case, the flexible structural element acts as a mechanical stiffener to provide stiffness to the balloon member and flexible framework.

[0074] The catheter shaft may comprise an inflation lumen coupled to the interior cavity of the balloon member. In the first delivery configuration, the balloon member may be uninflated and in the second deployed configuration the balloon member may be inflated (expanded), optionally via a liquid or a gas delivered through the inflation lumen. The inflation lumen may be an oval inflation lumen. The balloon member may be inflated via saline, oxygen, nitrogen dioxide (e.g., which can also be used for cryotherapy ablation of tissue), air, or any combination thereof. Such fluids are delivered through the inflation lumen to inflate and / or expand an interior cavity of the balloon member. Following the procedure, the inflation gas and / or liquid may be aspirated, suctioned and / or exhausted out through the inflation lumen and / or catheter shaft lumen.

[0075] The balloon member may be a compliant balloon member or a non-compliant balloon, depending on the material(s) of the balloon member and / or the level of inflation provided through the inflation lumen for transitioning the balloon member from the first delivery / deflated configuration to the second deployed / inflated configuration. The balloon member may comprise polyether block amide, such as Pebax. The balloon member material may be processed so as to allow the balloon member to elastically deform from a collapsed, first delivery configuration within a delivery sheath to an intermediate configuration wherein the balloon member is unconstrained from the delivery sheath and uninflated. For example, such manufacturing processes may include rolling the balloon member onto itself and heating the balloon member (e.g., in an oven at about 95° C) to thermoset the rolled balloon member in the first delivery configuration. As the balloon member exits the delivery sheath, the balloon member elastically deforms to the intermediate configuration which may comprise the balloon member being unrolled and having a substantially planar, flattened shape. The balloon member may further transition to the second configuration where the balloon member is inflated.

[0076] In the delivery configuration, the balloon member is collapsed, rolled, or folded into an inner lumen of a delivery sheath. The balloon member may additionally have folding lines, ribs, pleats and / or divot points to help align and facilitate delivery of the expandable electrode assembly within the delivery sheath. In the first delivery configuration, the balloon member is advanced out of the delivery sheath (and / or the delivery sheath is retracted proximally) in a deflated state. In the second deployed configuration, the balloon member is expanded via the flexible structural element or by inflation with a gas, liquid, or combination thereof. Following the procedure, the flexible structural element and balloon member may becollapsed and retracted back into the delivery sheath. Alternatively, the inflation gas and / or liquid may be aspirated, suctioned and / or exhausted out through the inflation lumen and / or catheter shaft lumen and the balloon member may be collapsed and retracted back into the delivery sheath. The balloon member together with the delivery sheath can be removed from the patient.

[0077] The balloon member may have a substantially flat (or planar) shape, concave shape, or convex shape in the second deployed configuration. The balloon member may have a fold line down the centre of the flat shape which directs the inflated balloon member into a “football” shape. The second configuration may include an over-inflated configuration which extends the balloon member beyond the flat shape such that a central portion of the balloon member may extend outwardly, for example, above the rest of the top surface and / or the bottom surface of the balloon member (e.g., to irrigate the tissue via the interior cavity of the balloon member). As such, it will be appreciated that the balloon member may comprise multiple expanded configurations (e.g., in the intermediate configuration, in the second deployed configuration, etc.).

[0078] The expandable electrode assembly and / or the balloon member may be any shape including a circle (e.g., forming a “lollipop” shape), a triangle, a square, a rectangle, etc., or any combination of shapes. The balloon member may be substantially oval in shape. The expandable electrode assembly and / or the balloon member may have a linear shape or a hoop shape having one or more interior “cut-outs” as would be appreciated by one having ordinary skill in the art. Exemplary embodiments of a rounded shape or basket having inflatable portions may include those described with respect to U.S. Patent Pub. No. 2021-0361220 Al entitled “Uniform Mapping Balloon” the entire disclosure of which is incorporated herein by reference. Any inflatable portion may be partially inflatable to fully inflated, and vice versa, before, during, and after use as desired for the intended application.

[0079] A substantially flat balloon member enables improved determination of tissue or blood contact at the electrode interface. For example, one side of the substantially flat balloon member may be configured to contact the tissue of interest (e.g., cardiac tissue) while the other side of the substantially flat balloon member is configured to contact blood flow, etc. These discrete and reliable electrode contact points on the flat balloon structure that are independently energized allow for measurements at the blood pool interface to be filtered out to remove any far field artifacts. This in turn provides higher fidelity electrograms (EGMs)with improved signal to noise ratio as compared to conventional mapping techniques known in the art. For example, conventional mapping catheters measure the average of signals at the tissue and blood interface. The discrete contact determination and sensing enabled by the substantially flat balloon structure of the present invention reduces or eliminates such far field effects and unwanted noise in measurements. Additionally, equally spaced electrodes are measured from known directions and associated algorithms do not have to compensate for timing delays. The ability to have discrete contact sides also improves spatial resolution with respect to borders / edges, for example, with respect to high / low voltage, timing maps, etc., as compared to conventional devices.

[0080] A further advantageous feature of a substantially flat or planar expandable electrode assembly is that each of the surfaces is able to maintain the electrodes in their desired configurations. For example, the arrangement of the electrodes (e.g., the spacing of the electrodes) remains substantially fixed, even when the distal portion of the expandable electrode assembly contacts tissue or the top surface / bottom surface are bent. This consistent and equal spacing of electrodes in turn provides for improved sensing and diagnostic mapping.

[0081] The first plurality of electrodes and second plurality of electrodes may be equally spaced. The electrodes may be separated from each other by approximately 0.20 to 5mm, 0.5 to 4mm, 1 to 3 mm, or by 1mm, 1.5mm, 2mm, 2.5mm, 3mm or 4mm (centre-to-centre distance). The electrodes may be separated from each other by an edge-to-edge distance of approximately 0.20 to 4mm, 0.75 to 3mm, 1 to 2 mm.

[0082] The balloon member may comprise a plurality of apertures on the outer facing layer of the top surface and the bottom surface of the balloon member. The apertures may be configured to expose the respective first plurality of electrodes and the second plurality of electrodes. A diameter of the plurality of apertures may be the same size or smaller than a diameter of the respective first and second plurality of electrodes. The plurality of apertures may have a diameter in a range from 0.25mm to 3mm and the electrodes may have a diameter in a similar range from 0.25mm to 3mm. Alternatively, the diameter of plurality of apertures and the diameter of the electrodes may have any desired dimension. For example, the electrodes may be between about 0.002 and about 0.010 larger than the apertures. The diameter of the apertures may be the same size as the diameter of the electrodes. Thediameter of the apertures may be larger than the diameter of the electrodes. There may be an insulating seal between the electrode and the aperture.

[0083] Each of the first plurality of electrodes and the second plurality of electrodes may be arranged in horizontal rows relative to the longitudinal axis of the elongate catheter shaft. The horizontal rows may be offset such that each electrode in each row is offset from a respective electrode in an adjacent row. Each of the first plurality of electrodes and the second plurality of electrodes may be arranged in vertical rows parallel to the longitudinal axis of the elongate catheter shaft. The vertical rows may be offset such that each electrode in each row is offset from a respective electrode in an adjacent row. The horizontal and / or vertical offset may be in a range from 22.5° to 60°, preferably 60°. The electrodes may be patterned in offset rows for more equally spaced electrode groupings. Associated algorithms do not have to compensate for timing delays leading to more accurate mapping and sensing capabilities. The first plurality of electrodes and the second plurality of electrodes may be aligned such that an electrode on the top surface of the balloon member matches with an electrode on the bottom surface of the balloon member. Alternatively, the first plurality of electrodes and the second plurality of electrodes do not align with each other.Fifth aspect

[0084] According to a fifth aspect of the invention, there is provided a catheter comprising: a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis, and a flexible tip portion. The flexible tip portion comprises: a flexible framework comprising at least one substantially planar flexible substrate, wherein the substantially planar flexible substrate is petal-shaped and comprises a top (distal-most, tissue-contacting) surface and a bottom (proximal-most) surface, wherein the substantially planar flexible substrate has a free distal end and a proximal end that is coupled to the distal end of the catheter shaft. The flexible tip portion further comprises a plurality of electrodes coupled to the at least one substantially planar flexible substrate; and a distal hub located at the distal end of the catheter shaft. The flexible petal-shaped substrate is adapted to transition between a first delivery configuration to a second deployed configuration wherein the free distal end of the flexible petal-shaped substrate is positioned radially outwardly from the proximal end and the substantially planar flexible substrate comprises a shape memory material to predispose the flexible petal-shaped substrate in a plane at an angle in the rangefrom 80 to 130 degrees to the longitudinal axis of the catheter shaft. The shape memory material may be nitinol.

[0085] The flexible tip portion preferably comprises: a flexible framework comprising a plurality of substantially planar flexible substrates, wherein each substantially planar flexible substrate is petal-shaped and comprise a top surface and a bottom surface, wherein each substantially planar flexible substrate has a free distal end and a proximal end that is coupled to the distal end of the catheter shaft. The flexible tip portion further comprises a plurality of electrodes coupled to the substantially planar flexible substrates; and a distal hub located at the distal end of the catheter shaft and central to the substantially planar flexible substrates. Each of the flexible petal-shaped substrates is adapted to transition between a first delivery configuration to a second deployed configuration wherein the free distal end of each flexible petal-shaped substrate is positioned radially outwardly from the proximal end and each substantially planar flexible substrate comprises a shape memory material to predispose the flexible petal-shaped substrates in a plane at an angle in the range from80 to 130 degrees to the longitudinal axis of the catheter shaft. The shape memory material may be nitinol.Flexible framework

[0086] In the deployed configuration, each of the substantially planar flexible substrates is predisposed in a plane at an angle in the range from 80 to 130° to the longitudinal axis of the catheter shaft. The substantially planar flexible substrates may be predisposed in a plane orthogonal to the longitudinal axis of the catheter shaft. The substantially planar flexible substrates may be predisposed in a plane at an angle of greater than 90° to the longitudinal axis of the catheter shaft. The substantially planar flexible substrates may be predisposed in a plane at an angle of less than 90° to the longitudinal axis of the catheter shaft, particularly from 80 to 90° to the longitudinal axis of the shaft. In the second deployed configuration, the free distal end of each flexible petal-shaped substrate is positioned radially outwardly from the proximal end such that the top (distal-most) surfaces of each flexible petal-shaped substrate can be in contact with tissue upon exertion of a contact force on the flexible framework by the tissue. The angle of the plane of the flexible framework means that the catheter can be used with a “push” handling mechanism. This may also give the operator visual feedback when tissue contact is made and allows for better recovery from reaction forces upon contact of the flexible framework with tissue.

[0087] The flexible tip portion may be adapted to conform to a tissue. That is, the flexible tip portion, including the substantially planar flexible substrates of the flexible framework can bend and flex to conform to a tissue in the deployed configuration. The substantially planar flexible substrates may have a degree of flexure when fully deployed. The substantially planar flexible substrates may provide a flexible framework having a much larger surface area than the cross-section of the catheter shaft as presented to tissue. The substantially planar flexible substrates may have a total surface area of 5mm x 5mm to 30mm x 30mm, for example, 12mm x 12mm. The substantially planar flexible substrates may have a length extending from the proximal to the distal end of between 3 to 10mm, 4 to 8mm, and 5 to 7mm, and a maximum width (measured perpendicular the length) of between 3 to 5mm, around 4mm. The distal hub may have a diameter of between 3 to 8mm, optionally 5mm. Other dimensions are envisaged.

[0088] The flexible framework may comprise at least one substantially planar flexible substrate. The total number of substantially planar flexible substrates is not limited. There may be 1 to 12 substantially planar flexible substrates, preferably two, three, four, five, six or seven substantially planar flexible substrates. The substantially planar flexible substrates are each petal-shaped (or T-shaped, as discussed below).

[0089] The flexible framework is configured to have an expanded state in a deployed configuration and a collapsed configuration. The flexible tip portion is configured to fold up or collapse into a smaller arrangement / configuration (first delivery configuration) to permit the flexible tip portion to fit into a desired size and / or shape.

[0090] The catheter may further comprise an introducer sheath configured for advancement over the flexible tip portion to bring the substantially planar flexible substrates into a first delivery configuration and for retraction from the flexible tip portion to bring the substantially planar flexible substrates into a second deployed configuration. The flexible tip portion is deliverable through and into bodily organs, such as but not limited to the heart. In preparation for insertion of the catheter, the flexible tip portion is compressed to fit within the introducer sheath (which may include a delivery catheter or an elongate tubular member). The flexible tip portion is deliverable through and past the distal end of the introducer sheath. Full retraction of the introducer sheath causes the flexible tip portion to expand as it exits the distal end of the sheath. Expansion of the flexible tip portion allows the substantially planar flexible substrates to splay open. In the second configuration, the plurality of substantiallyplanar flexible petal-shaped substrates can be arranged around the distal end of the catheter shaft to form a flower shape. The substantially planar flexible substrates fold in towards one another and / or towards the central longitudinal axis when the introducer sheath is advanced over the flexible tip portion for delivery and storage. Selective retraction of the introducer sheath may allow for a portion of the substantially planar flexible substrates to be exposed. For example, a first band of electrodes on each of the substantially planar flexible substrates may be exposed.

[0091] Each of the substantially planar flexible substrates may bow outwardly into the second deployed configuration. The nitinol (super-elastic / shape memory material) provides stability for the flexible tip portion, such that substantially planar flexible substrates assume an expanded shape when not subjected to any external forces or biases (e.g. from the introducer sheath). The super-elastic material can allow the flexible tip portion to hold its second deployed configuration (e.g. an expanded shape) during mapping and therapy use. The expanded shape may be a radially expanded shape. The overall shape of the deployed flexible tip portion may be an expanded, non-cylindrical shape.

[0092] The flexible framework may comprise two or more substantially planar flexible substrates and the substantially planar flexible substrates may be distributed around the distal end of the catheter shaft. The substantially planar flexible substrates may be evenly distributed around the distal end of the catheter shaft. Alternatively, the substantially planar flexible substrates may be unevenly distributed around the distal end of the catheter shaft, for example, they may be distributed around one side of the distal end of the catheter shaft.

[0093] Each substantially planar flexible substrate may be petal-shaped. The petal shape may be any suitable petal shape. For example, the petal shape may be selected from one of elliptical, truncate, obovate, ovate, lanceolate, and round. An elliptical petal shape may be defined by an oval shape with a small or no tip. An obovate shape may be egg-shaped having a proximal end which is narrower than the distal end. The dimensions of the petal-shapes may be varied as required. Petals may be long and thin, or shorter and broader / wider. A plurality of long, thin petal-shaped substantially planar flexible substrates may be used for linear lesion creation. One or a few shorter, broader petal-shaped substantially planar flexible substrates may be used for larger surface area lesions and fast mapping. The petal-shaped substantially planar flexible substrates may form an open flower arrangement in the second deployed configuration. Alternatively, each substantially planar flexible substrate may take any suitableshape, such as a portion of a circle, an ellipsoid, a quadrilateral-shape (including a rounded rectangle), an anvil shape or a curved T-shape.

[0094] The substantially planar flexible substrates are formed from nitinol. Each substantially planar flexible substrate has a top (distal-most, tissue-contacting) surface and a bottom (proximal-most) surface. Each substantially planar flexible substrate has a free distal end and a proximal end that is affixed to the distal end of the catheter shaft. Affixing the substantially planar flexible substrates to the distal end of the catheter shaft captures direct and indirect connection of the substantially planar flexible substrates at the distal end of the catheter shaft.Electrodes and flexible circuits

[0095] The shape memory material may comprise nitinol and an entire top surface (tissuecontacting) of each of the substantially planar flexible substrates may be configured to form an ablation electrode. The nitinol of the entire bottom surface of each of the substantially planar flexible substrates may be configured to form an ablation electrode. The nitinol of each of the substantially planar flexible substrates may be selectively or independently energizable. That is, the ablation electrodes can be selectively or independently switched on and off or polarized. Adjacent ablation electrodes formed by the nitinol of the top surface of the substantially planar flexible substrates may be of opposite polarity. Where there are four, evenly distributed substantially planar flexible substrates, diametrically opposite ablation electrodes may have the same polarity. All ablation electrodes on a top (tissue-contacting) surface may have the same polarity, and a distal hub electrode located at the distal hub may have the opposite polarity.

[0096] A plurality of electrodes are coupled to the substantially planar flexible substrates. “Coupled to” can encompass electrodes being “patterned” on to the substantially planar flexible substrates, “deposited” on to the substantially planar flexible substrates, “mounted on” the substantially planar flexible substrates or any other means of disposing the plurality of electrodes on the substantially planar flexible substrates. For example, each electrode of the plurality of electrodes may be deposited on the bottom surface and / or the top surface of the substantially planar flexible substrate. The electrodes may be spot electrodes, optionally multiple spot electrodes can be shorted together to act as a single, longer electrode.Electrodes may be configured as mapping or ablation electrodes. The plurality of electrodes may be coupled to at least the bottom (proximal-most) surface of each of the substantiallyplanar flexible substrates. The electrodes on the bottom surface may be configured as mapping electrodes. The plurality of electrodes may also be coupled to the top (tissuecontacting) surface of each of the substantially planar flexible substrates. Electrodes on the top surface may be configured as mapping or ablation electrodes. Electrodes on the top surface may be aligned with the electrodes on the bottom surface (each top-surface electrode is positioned directly opposed to a bottom-surface electrode). The electrodes may be selectively or independently energizable. Selectively energizing the electrodes can allow individual electrodes to act independently for mapping or ablation. Selectively energizing groups of electrodes can provide larger surface area coverage for mapping or ablation. The plurality of electrodes coupled to the substantially planar flexible substrates may be electrically isolated and independently activated from the substantially planar petal-shaped substrate for ablation.

[0097] Each electrode of the plurality of electrodes may be configured as a band on the bottom surface and / or the top surface of the substantially planar flexible substrate. The electrode band may extend from one margin (edge) of the substantially planar flexible substrate to the other margin (edge) of the substantially planar flexible substrate. There may be a row of longitudinally-aligned electrode bands distributed along each of the substantially planar flexible substrate. Electrode bands may be equally and / or evenly spaced between the proximal and distal ends of the substantially planar flexible substrate. The electrode bands may be separated from each other by approximately 0.20 to 5mm, 0.5 to 4mm, 1 to 3 mm, or by 1mm, 1.5mm, 2mm, 2.5mm, 3mm or 4mm (centre-to-centre distance). Adjacent electrode bands may be of opposite polarity. The electrode bands may be selectively or independently energizable. For example, the first electrode band on each substantially planar flexible substrate (the proximal electrode band) may be energized. The skilled person will appreciate that any combination of electrode bands can be energized as required. Electrode bands on the top surface and bottom surface may have the same polarity.

[0098] The plurality of electrodes may comprise a first electrode arrangement configured for ablation, and / or a second electrode arrangement configured for mapping, wherein the first arrangement is larger than the second arrangement. Larger electrodes may be configured for ablation, smaller electrodes may be configured for mapping and / or one or more electrodes for combined use. Therapy electrodes on the top surface of the substantially planar flexible substrates can be used to direct energy at the tissue to be ablated. The surface area of mapping electrodes on the top and / or bottom surface of the substantially planar flexiblesubstrates may be smaller than the surface area of ablation electrodes on the top and / or bottom surface of the substantially planar flexible substrates to minimize far field sensed electrical signals. Smaller size mapping electrodes can facilitate the creation of high-resolution maps. Each substantially planar flexible substrate may include three or more mapping electrodes and one or more ablation electrode. A single surface (top or bottom) of the substantially planar flexible substrates may be used to map and ablate. Electrodes for each function are separate from one another.

[0099] The first electrode arrangement (larger, ablation electrodes) may be located near the distal end of each of the substantially planar flexible substrates. The second electrode arrangement (smaller, mapping electrodes) may be located near the proximal end of each of the substantially planar flexible substrates. The plurality of electrodes may each be independently activated for mapping or ablation.

[0100] The catheter may further comprise a flexible circuit mounted on at least the bottom surface of each of the substantially planar flexible substrates. A flexible circuit may be mounted on the top and bottom surface of each of the substantially planar flexible substrates. A plurality of flexible circuits may be mounted on the top and / or bottom surface of each of the substantially planar flexible substrates. Here “mounted on” can encompass flexible circuits being “disposed” or “patterned” on to the substantially planar flexible substrates, or any other means of disposing the flexible circuit(s) on the substantially planar flexible substrate. The plurality of flexible circuits may be coupled to the plurality of electrodes for mapping.

[0101] Each substantially planar flexible substrate may further comprise at least one cutout region. The nitinol of the remaining portion of each of the plurality of substantially planar flexible substrates may be configured to form an ablation electrode. A flexible circuit may be included inside the cut-out region of each of the substantially planar flexible substrate. That is, the flexible circuit may be deposited on the side-wall of the cut-out region of the substantially planar flexible substrate. In addition, or alternatively, the flexible circuit may be deposited on a substrate positioned inside the cut-out region of the substantially planar flexible substrate.

[0102] Each substantially planar flexible substrate may comprise two layers of nitinol and at least one cut-out region is formed in both layers of nitinol. A flexible circuit layer may be positioned between the two nitinol layers and within the cut-out region. The flexible circuitlayer may be sandwiched between the two layers of nitinol. The flexible circuit may be coupled to the plurality of electrodes for mapping.

[0103] The plurality of electrodes may be disposed in the cut-out region, as part of the flexible circuit / flexible circuit layer. The at least one cut-out region may be located in a proximal section of the substantially planar flexible substate. The at least one cut-out region may be located in a centre of the substantially planar flexible substate. For example, the substantially planar flexible substate may form a thin perimeter around the cut-out region. The flexible circuit is coupled to the plurality of electrodes.

[0104] Each flexible circuit may comprise a plurality of conductive traces. Each of the plurality of conductive traces may be electrically coupled with a respective one of the plurality of electrodes. A mounting portion may be connected to the substantially planar flexible substrates, wherein the mounting portion includes a plurality of contact pads electrically coupled with the plurality of electrodes via the plurality of conductive traces. A nonconductive material, for example a dielectric material, may be disposed between each of the plurality of conductive traces and the substantially planar flexible substrates. The nonconductive material may cover an outer facing surface of each of the plurality of conductive traces.

[0105] Each flexible circuit comprises at least one of the plurality of electrodes disposed over at least part of the top (distal, tissue-contacting) surface and / or bottom (proximal-most) surface of the substantially planar flexible substrates, and one or more conductive traces. The conductive traces can be disposed over at least a portion of the bottom (proximal-most) surface of the substantially planar flexible substrates. In addition or alternatively, the conductive traces can be embedded within the substantially planar flexible substrates. In addition or alternatively, the conductive traces can be disposed over at least a portion of the top (distal-most) surface of the substantially planar flexible substrates. In addition or alternatively, the conductive traces can be sandwiched between two layers forming the substantially planar flexible substrate. The one or more conductive traces are in electrical communication with the electrodes.

[0106] The conductive traces may include doped polymers (“stretchy” conductors), such as gold embedded within a liquid crystal polymer or polymers doped with copper nanowires. The conductive traces may include a noble metal (e.g., platinum), titanium, copper and alloys thereof, optionally copper. The conductive traces may include a copper layer with a goldlayer on top to protect it from corrosion. The conductive traces may include a layer of platinum or iridium to improve mapping performance. The conductive traces may include a nickel layer in between a copper and gold layers to retard the diffusion of the copper into the gold, thus reduce the corrosion protection offered by the gold. Optional further layers of titanium may be included.

[0107] Preferably, the flexible circuit surface is substantially flat, i.e., any nonconductive material and the electrodes being substantially the same height. Alternatively, the electrodes may protrude slightly above the nonconductive material surface. The electrode surface may be raised with the use, for example, of strips of material disposed between the substantially planar flexible substrates and the electrodes. Other ways of raising the electrode surface may be implemented. Alternatively, the electrodes may be depressed slightly below the substantially planar flexible substrate surface.

[0108] The nonconductive material may cover an outer facing surface of each of the plurality of conductive traces. The nonconductive material may provide electrical insulation. Any electrodes being substantially free of the additional nonconductive material. The nonconductive material may comprise an insulating material, preferably a dielectric material. The nonconductive material may comprise a polyethylene terephthalate (PET) heat shrink material, polyurethane, nylon, parylene, a polyimide (e.g., PI-2771 or HD-4004 available from HD Microsystems, or KAPTON available from DuPont), a polyether block amide (such as Pebax®), and / or an epoxy (e.g., SU8 epoxy available from MicroChem Corp)). Preferably the nonconductive material is selected from polyurethane, nylon and a polyether block amide, more preferably a polyether block amide.

[0109] The nonconductive material may further extend laterally outward with respect to the substantially planar flexible substrates to form a protective coating. The nonconductive material may extend around the perimeter of each of the substantially planar flexible substrates to form a protective coating. The nonconductive material protective coating may surround the perimeter or outer edge of each of the substantially planar flexible substrates. The nonconductive material protective coating protects the perimeter (edges or margins) of the substantially planar flexible substrates and provides an atraumatic edge.

[0110] The flexible circuit (or any layer thereof) may be directly or indirectly attached to the substantially planar flexible substrates. Each flexible circuit may include at least one adhesive layer. The adhesive layer may include polyurethane, cyanoacrylate, polyvinylacetate, acrylic, polyimide, epoxy, hot melt or fluoropolymer adhesives. Alternatively, each flexible circuit may not include an adhesive layer. Thermal bonding may include the application of heat and / or compressive pressure to the layers. The flexible circuit may also be directly printed onto or applied to the substantially planar flexible substrates as described in US 10,595,738 B2 and US 11,039,773 B2.[OHl] A protective coating may be provided around the perimeter of each of the substantially planar flexible substrates. The protective coating may surround the perimeter or outer edge of each of the substantially planar flexible substrates. The protective coating protects the perimeter (edges or margins) of the substantially planar flexible substrates and provides an atraumatic edge. The protective coating can act as a protector / bumper to prevent any sharp edges of the substantially planar flexible substrates from contacting other materials (e.g., inner diameter of an introducer sheath, tissues in the heart, etc.). The protective coating may be any suitable polymeric material. The polymeric material may be selected from polytetrafluoroethylene polyethylene, ‘PTFE’, (e.g. expanded-PTFE), polyethylene terephthalate (PET), polyester, polyethylene, polyolefins (e.g. HDPE), poly(vinyl chloride), polyurethane, nylon, parylene, a polyimide (e.g., PI-2771 or HD-4004 available from HD Microsystems, or KAPTON available from DuPont), a polyether block amide (such as Pebax®), and / or an epoxy (e.g., SU8 epoxy available from MicroChem Corp)), or combinations thereof. The protective coating may be formed directly on the perimeter of the substantially planar flexible substrate or may be a pre-formed cover applied to the substantially planar flexible substrate.

[0112] The distal hub is located at the distal end of the catheter shaft and central to the substantially planar flexible substrates. “Located at” encompasses positioning the distal hub at the distal end of the catheter shaft. The distal hub is within the flower arrangement in the delivery and deployed configurations. The distal hub may be substantially flat, or alternatively, may be a three-dimensional shape (such as a hemisphere). The catheter may further comprise a distal hub electrode located at the distal hub. The distal hub electrode may be independently and selectively energized to have the same or different polarity as one or more of the nitinol ablation electrodes (top surface of the substantially planar flexible substrate). The distal hub electrode may be independently and selectively energized to have the same or opposite polarity as the first electrode band on each substantially planar flexible substrate (the proximal electrode band).

[0113] The catheter may further comprise at least one steering ring at or near the distal end of the catheter shaft. A steering ring may be located as close to the distal end of the catheter shaft as possible. The steering ring may be within a distal portion of the catheter shaft, for example within the distal end of the catheter shaft, or may surround a distal portion of the catheter shaft. The steering ring may be connected to one or more pull wires to facilitate movement / steering of the catheter shaft. At least one pull wire may be disposed longitudinally along the length of the catheter shaft. The distal end of the at least one pull wire can be connected to the at least one steering ring. The steering ring located as close to the distal end of the catheter shaft as possible advantageously enables maximum reach and maneuverability of the catheter and flexible tip portion. The catheter may include a handle which has a steering mechanism. The proximal end of the at least one pull wire may be connected to said steering mechanism. The pull wire may be a flat wire having a substantially rectangular cross-section. The pull wire may have a width of at least 0.178mm and a thickness of at least 0.076mm.Other features applicable to aspects 1 to 5

[0114] The catheter shaft may comprise at least one fluid delivery lumen adapted to be fluidly coupled to a source of irrigant. The at least one fluid delivery lumen may be internal and longitudinally-extending. The catheter may comprise at least one irrigation hole in fluid communication with the at least one fluid delivery lumen. The fluid delivery lumen may be adapted to deliver the irrigant through the at least one irrigation hole to the flexible substrate and / or on or adjacent to the planar array of electrodes.

[0115] Multiple irrigation holes or ports could be present at various positions along the electrode-carrying arms, flexible struts, flexible structural element and / or catheter shaft. At least one irrigation hole (or port) may be present at the distal end of the catheter shaft, for example, at the distal end of the proximal coupler or at the distal hub of aspect five. One or more distal irrigation holes (or ports) could be included at or near the distal end of the flexible tip and / or expandable assembly.

[0116] There may be a number of additional electrodes located on the catheter shaft. There may be at least one electrode mounted on the distal end of the catheter shaft, preferably adjacent to the flexible tip portion. The proximal coupler may comprise a proximal coupler cap, which may be configured to be electrically active (e.g. metallic), and / or there may be atleast one electrode mounted on the proximal coupler cap. There may additionally or alternatively be at least one electrode mounted on the proximal coupler.

[0117] In particular, there may be an electrode mounted on the most distal part of the catheter shaft (e.g. at the proximal coupler cap), and two further electrodes positioned on the catheter shaft; a distal shaft electrode and a proximal shaft electrode. The distal shaft electrode may be approximately 2.5 mm from the proximal coupler cap electrode and the proximal shaft electrode may be spaced approximately 4 mm from the distal shaft electrode. Any of the additional electrodes may be ring electrodes.

[0118] In one example, the catheter may comprise 16 electrodes on the electrode-carrying arms, 1 proximal electrode at the proximal coupler cap, and 2 catheter shaft electrodes (a distal shaft electrode and a proximal shaft electrode).Manufacturing Methods

[0119] A sixth aspect of the invention relates to a method of manufacturing a medical device. The medical device may be a catheter. The method comprises: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis; disposing shape memory material into a plurality of electrode-carrying arms and arranging at least a portion of each of the electrode-carrying arms into a single common plane to form a flexible framework; disposing the electrode-carrying arms at the distal end of the catheter shaft to form a flexible tip portion of the catheter and setting the shape of the flexible tip portion such that the plane of the flexible framework is predisposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; and securing the electrode-carrying arms to the distal end of the catheter shaft.

[0120] The shape memory material may comprise nitinol. Disposing the nitinol shape memory material into a plurality of electrode-carrying arms and arranging at least a portion of each of the electrode-carrying arms into a single common plane may comprise bending the material to form the electrode-carrying arms and fixing that shape to form a planar flexible framework. Wherein the fixing of the shape of the electrode-carrying arms may take place at a temperature in a range of 490-540°C. The fixing may be achieved by submerging the planar flexible framework in a salt bath until the shape memory material reaches a temperature in a range of 490-540°C. The fixing time per part may be 75-120 seconds. Fixing is followed by quenching of the arms. The quenching may take place in room temperature water.

[0121] The nitinol shape memory material wire may be bent to form one or more bent loops, for example a D-shaped loop or a rectangular-shaped loop. The bend angles may be 90 degrees.

[0122] Setting the shape of the flexible tip portion may include: bending a portion of the shape memory material such that the plane of the flexible framework is at the angle in the range of 80 to 130 degrees to the longitudinal axis of the catheter shaft; fixing the framework; and quenching. The plane of the flexible framework may be set orthogonal to the longitudinal axis of the catheter shaft, or at an angle of greater than 90° to the longitudinal axis of the catheter shaft, or at an angle of less than 90° to the longitudinal axis of the catheter shaft. As for the manufacture of the flexible framework, the fixing of the bent shape of the flexible framework may be achieved by submerging the bent part in a salt bath until the shape memory material reaches a temperature in a range of 490-540°C. The fixing time per part may be 75-120 seconds. Fixing is followed by quenching of the flexible framework. The quenching may take place in room temperature water. During the bending, a portion of the shape memory material may remain parallel to the longitudinal axis of the catheter shaft. There is no recovery or “springback” of the shape memory material after the quenching stage.

[0123] Another method of manufacturing a medical device is provided. The medical device may be a catheter. The method comprises: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis; disposing shape memory material into a plurality of electrode-carrying arms and arranging at least a portion of each of the electrode-carrying arms into a single common plane to form a flexible framework; disposing the electrode-carrying arms at the distal end of the catheter shaft to form a flexible tip portion of the medical device and setting the shape of the flexible tip portion such that a portion of the flexible framework forms a plane predisposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; and securing the electrode-carrying arms to the distal end of the catheter shaft. The shape memory material may comprise nitinol. Disposing the nitinol shape memory material into a plurality of electrode-carrying arms and arranging at least a portion of each of the electrode-carrying arms into a single common plane may comprise bending the material to form the electrode-carrying arms and fixing that shape to form a planar flexible framework. Setting the shape of the flexible tip portion may include: bending a portion of the flexible framework such that a distal portion of the flexible framework forms a plane predisposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; fixing the framework; and quenching. A proximalportion of the planar flexible framework may be set substantially parallel to the longitudinal axis of the catheter shaft, and a distal portion of the planar flexible framework may be set substantially perpendicular to the longitudinal axis of the catheter shaft. Fixing of the bent flexible framework may be achieved by submerging the bent part in a salt bath until the shape memory material reaches a temperature in a range of 490-540°C. Fixing is followed by quenching. During the bending, a portion of the flexible framework may remain parallel to the longitudinal axis of the catheter shaft. There is no recovery or “springback” of the shape memory material after the quenching stage.

[0124] Bending of the shape memory material may be over an appropriately-sized tool to give the required bending angle and radius of curvature. Preferably, the bent portion of the shape memory material has a radius of curvature in a range of 3 to 5mm, preferably 3.81mm.

[0125] Securing the electrode-carrying arms at the distal end of the catheter shaft captures direct and indirect connection of the electrode-carrying arms at the distal end of the catheter shaft. Securing may include passing the proximal end of the electrode-carrying arms into the distal end of the shaft and securing in place. The proximal ends of the electrode-carrying arms may be passed into a proximal coupler located at the distal end of the catheter shaft before securing in place.

[0126] One or more additional flexible frameworks may be made in the same manner. Once the flexible framework is shape-set, and the flexible tip portion is shape set, the one or more additional flexible frameworks may be secured at the distal end of the catheter shaft. The one or more additional flexible frameworks may be distributed around the distal end of the catheter shaft and respective electrode-carrying arms secured at the distal end of the catheter shaft. The additional flexible frameworks may be evenly distributed around the distal end of the catheter shaft, or alternatively, the additional flexible frameworks may be distributed around one side of the distal end of the catheter shaft.

[0127] A plurality of electrodes may be coupled to the plurality of electrode-carrying arms. As above, “coupled to” can encompass electrodes being “patterned” on to the electrodecarrying arms, “deposited” on to the electrode-carrying arms, or electrodes which are ring electrodes disposed around the electrode-carrying arms, or any other means of disposing the plurality of electrodes on the electrode-carrying arms. Additionally, a plurality of conductive traces and / or flexible circuits may be disposed on the flexible tip portion.

[0128] A polymeric tube may be disposed over the shape memory material electrodecarrying arms. The coupling a plurality of electrodes on the plurality of electrode-carrying arms may comprise mounting the electrodes on the polymeric tube of each of the plurality of electrode-carrying arms. The framework comprising the polymeric tube may then be annealed. Alternatively, an annealed polymeric tube may be disposed over the shape memory material electrode-carrying arms. The coupling a plurality of electrodes on the plurality of electrode-carrying arms comprises mounting the electrodes on the pre-annealed polymeric tube of each of the plurality of electrode-carrying arms. Annealing of the polymeric tube (prior to disposing over the shape memory material, or once it is in situ) may take place at a temperature of 80 to 105°C. Annealing may be conducted by any suitable means, for example in an oven or via the application of directed hot air to the polymeric tube for a period of time. A more concentrated beam of hot air (for example, using a heat gun) can improve the annealing process. Annealing the polymeric tube can make the polymeric tube more workable and facilitate reshaping the tube, for example, to have a bend similar to the electrode-carrying arms. Annealing of the polymeric tube advantageously reduces the kinking or creasing of the polymeric tube when the flexible framework is deflected.

[0129] A seventh aspect of the invention relates to a further method of manufacturing a medical device. The medical device may be a catheter. The method comprises: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis; disposing a shape memory material into an intermediate portion at a distal end of the catheter shaft and setting the shape memory material into at least a partial loop disposed in a plane, wherein the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; disposing a flexible framework comprising a plurality of electrode-carrying arms at the distal end of the intermediate portion, wherein each of the plurality of electrode-carrying arm converges with at least one other of the plurality of electrode-carrying arms at a distal end of the flexible framework, wherein the electrode-carrying arms of the flexible framework are arranged in-plane in a single common plane, such that the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; and securing the intermediate portion to the distal end of the catheter shaft.

[0130] The shape memory material may comprise nitinol. The shape memory material may be in the form of strips (e.g. cut from a sheet), or a wire, or any suitable form. The loop ispreferably made from a nitinol wire. The electrode-carrying arms are preferably made from strips of a nitinol sheet.

[0131] The flexible framework may be made by disposing a nitinol shape memory material into a plurality of electrode-carrying arms and arranging at least a portion of each of the electrode-carrying arms into a single common plane. Making the flexible framework may include bending the material to form the electrode-carrying arms and fixing that shape to form the planar flexible framework. Wherein the fixing may be achieved by submerging the planar flexible framework in a salt bath until the shape memory material reaches a temperature in a range of 490-540°C. The fixing time per part may be 75-120 seconds. Fixing is followed by quenching. The quenching may take place in room temperature water.

[0132] The plurality of electrode-carrying arms may comprise a shape memory material. Each electrode-carrying arm may extend from the distal end of the catheter shaft and through the intermediate portion. The setting the shape memory material into the at least a partial loop includes setting the shape memory material of the plurality of electrode-carrying arms into at least a partial loop as part of the intermediate portion. Alternatively, disposing a flexible framework comprising a plurality of electrode-carrying arms at the distal end of the intermediate portion comprises securing a proximal end of each electrode-carrying arm to the distal end of the intermediate portion. Securing the electrode-carrying arms at the distal end of the intermediate portion captures direct and indirect connection of the electrode-carrying arms at the distal end of the intermediate portion. The proximal ends of the electrode-carrying arms may be passed into a proximal coupler located at the distal end of the intermediate portion before securing in place.

[0133] The plane of the flexible framework may be set orthogonal to the longitudinal axis of the catheter shaft, or at an angle of greater than 90° to the longitudinal axis of the catheter shaft, or at an angle of less than 90° to the longitudinal axis of the catheter shaft.

[0134] A plurality of electrodes may be coupled to the plurality of electrode-carrying arms. As above, “coupled to” can encompass electrodes being “patterned” on to the electrodecarrying arms, “deposited” on to the electrode-carrying arms, or electrodes which are ring electrodes disposed around the electrode-carrying arms, or any other means of disposing the plurality of electrodes on the electrode-carrying arms.

[0135] A polymeric tube may be disposed over the electrode-carrying arms. The mounting a plurality of electrodes on the plurality of electrode-carrying arms may comprise mountingthe electrodes on the polymeric tube of each of the plurality of electrode-carrying arms. The framework comprising the polymeric tube may then be annealed prior to securing to the distal end of the intermediate portion.

[0136] Additionally, a plurality of conductive traces and / or flexible circuits may be disposed on the flexible tip portion.

[0137] An eighth aspect of the invention relates to a further method of manufacturing a medical device. The medical device may be a catheter. The method comprises: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis; disposing a shape memory material into a plurality of struts and setting the shape memory material of each of the plurality of struts into a curved shape; coupling a flexible framework comprising a substantially planar flexible substrate to the distal ends of each of the plurality of struts, wherein the flexible substrate is disposed in a plane that is at an angle in range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; and securing the plurality of struts to the distal end of the catheter shaft.

[0138] The curved shape may comprise a wave shape or a multi-curve shape, such as a double-curve shape. The curved shape may be an S-shape.

[0139] Disposing the struts at the distal end of the catheter shaft may comprise disposing the struts at an expansion angle of about 30 to 60 degrees to the longitudinal axis of the catheter shaft, optionally at an expansion angle of about 45 degrees to the longitudinal axis of the catheter shaft. There may be four curved struts and disposing the curved struts at the distal end of the catheter shaft can include placing the four struts to form an expansion angle with the longitudinal axis of the catheter shaft. For example, four struts may be placed such that the proximal end of each flexible strut forms an angle (“expansion angle”) of about 30 to 60 degrees, 35 to 55 degrees or 40 to 50 degrees to the longitudinal axis of the catheter shaft, pointing away from a central axis of the catheter shaft arranged around four corners of a square or rectangle.

[0140] The substantially planar flexible substrate may comprise a plurality of electrodes mounted or patterned on a top and / or bottom surface of the substrate.

[0141] The method may further comprise disposing a polymeric tube over at least one of the shape memory material struts. The method may further comprise mounting a plurality of electrodes on the plurality of flexible struts and / or polymeric tube. The method may furthercomprise annealing the struts comprising the polymeric tube, optionally wherein annealing takes place at a temperature of 82 to 105°C.

[0142] The shape memory material may comprise nitinol. Disposing the nitinol shape memory material into a plurality of flexible struts and setting the shape memory material into a curved shape may comprise bending the material to form the flexible struts and fixing that shape. Setting the shape of the plurality of struts may comprise bending the shape memory material into the curved shape, fixing the curved shape and quenching. The fixing may take place at a temperature in the range of 490-540 °C. The fixing may be achieved by submerging the planar flexible framework in a salt bath until the shape memory material reaches 490-540°C. The fixing time per part may be 75-120 seconds. Fixing is followed by quenching. The quenching may take place in room temperature water.

[0143] The coupling of the flexible framework comprising a substantially planar flexible substrate to the distal ends of each of the plurality of struts comprises coupling the flexible struts to a portion of the perimeter of the flexible substrate.

[0144] Securing the plurality of struts at the distal end of the catheter shaft captures direct and indirect connection of the plurality of struts at the distal end of the catheter shaft.Securing may include passing the proximal end of the plurality of struts into the distal end of the shaft and securing in place. The proximal ends of the plurality of struts may be passed into a proximal coupler located at the distal end of the catheter shaft before securing in place.

[0145] A ninth aspect of the invention relates to a method of manufacturing a medical device, in a manner similar to that described above with respect to the sixth aspect. The medical device may be a catheter. The method comprises: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis; disposing a shape memory material into a flexible structural element and disposing the flexible structural element at the distal end of the catheter shaft; setting the shape of the flexible structural element such that the plane of the flexible structural element is in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; and coupling the flexible structural element to the distal end of the catheter shaft.

[0146] A tenth aspect of the invention relates to a further method of manufacturing a medical device, in a manner similar to that described above with respect to the seventh aspect. The medical device may be a catheter. The method comprises: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinalaxis; disposing a shape memory material in an intermediate portion at a distal end of the catheter shaft and setting the shape memory material into at least a partial loop disposed in a plane, wherein the plane is disposed at in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; disposing a flexible structural element at the distal end of the intermediate portion; and securing the intermediate portion to the distal end of the catheter shaft.

[0147] The shape memory material may comprise nitinol. The specific conditions for the setting the shape memory material may be the same as those described above, and not repeated here.

[0148] The method according to the ninth or tenth aspects may further comprise preparing an expandable assembly comprising a plurality of layers. For example, preparing an expandable assembly comprising a balloon member having a top surface, a bottom surface, and an interior cavity, each of the top surface and the bottom surface having an outer facing layer and an inner facing layer; a top flexible framework disposed between the outer facing layer and the inner facing layer of the top surface of the balloon member; a bottom flexible framework disposed between the outer facing layer and the inner facing layer of the bottom surface of the balloon member; a first plurality of electrodes patterned onto the top flexible framework; a second plurality of electrodes patterned onto the bottom flexible framework, wherein the first plurality of electrodes are aligned with the second plurality of electrodes; and a plurality of conductive traces disposed on each of the flexible frameworks, each of the plurality of conductive traces electrically coupled with a respective one of the first plurality of electrodes and the second plurality of electrodes. The expandable assembly comprises a first delivery configuration, a second deployed configuration, and an intermediate configuration between the first delivery configuration and the second deployed configuration, wherein, in the intermediate configuration, the balloon member is unconstrained from an introducer sheath and uninflated, and the balloon member has a substantially planar shape.

[0149] The method may further comprise disposing the flexible structural element within the interior cavity of the balloon member, such that the plane of the balloon member in the intermediate configuration is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft. The method may further comprise securing the flexible structural element to the distal end of the catheter shaft, or to the distal end of the intermediate portion.

[0150] An eleventh aspect of the invention relates to a further method of manufacturing a medical device, the method comprising: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis; forming a flexible framework comprising at least one substantially planar petal-shaped flexible substrate comprising nitinol; and coupling the flexible framework to the distal end of the catheter shaft such that a proximal ends of each of the substantially planar flexible substrates is coupled to the distal end of the catheter shaft and setting the nitinol of the flexible framework such that a plane of each substantially planar flexible substrate defines an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft.

[0151] Coupling the flexible framework to the distal end of the catheter shaft may comprise adhesively and / or thermally bonding the proximal ends of each of the substantially planar flexible substrates to the distal end of the catheter shaft. Optionally, the proximal end a substantially planar flexible substrates may be thermally and / or adhesively bonded to the proximal end of at least one other of the substantially planar flexible substrates. A distal hub may be formed (machined, molded, cut etc.) from any suitable material, e.g. a polymer or nitinol sheet. A distal hub may be adhesively and / or thermally bonded to the proximal ends of each of the substantially planar flexible substrates at the centre of the flexible framework. The distal end of the catheter shaft and the distal hub may be disposed on opposite sides of the flexible framework, so as to sandwich the proximal ends of each of the substantially planar flexible substrates.

[0152] The method may further comprise coupling a plurality of electrodes onto a top and / or bottom surface of the substantially planar flexible substrates. The method may further comprise mounting at least one flexible circuit onto the top and / or bottom surface of each of the substantially planar flexible substrates. Mounting at least one flexible circuit may include depositing a plurality of conductive traces onto the top and / or bottom surface of each of the substantially planar flexible substrates. Mounting at least one flexible circuit may further include depositing at least one mounting portion onto at least a portion of a conductive trace, and depositing an electrode onto the mounting portion. Optionally, the mounting portion includes a plurality of contact pads configured to electrically couple the plurality of electrodes to the plurality of conductive traces. Contact pads may be conductive and may comprise solder pads.

[0153] The method may further comprise applying a protective coating to a perimeter of the substantially planar flexible substrates. The coating may be applied using any suitable technique. For example, the coating may be applied by dip-coating, spraying or direct application of the coating to the perimeter (edges or margins) of the substantially planar flexible substrate, and allowing to set. The coating may alternatively be applied by first forming a protective coating into a case, and then attaching the case to the perimeter of the substantially planar flexible substrate.

[0154] A cut-out region may be formed in the substantially planar flexible substrates. The method may further comprise mounting at least one flexible circuit inside the cut-out region, i.e. into the cavity left by the cut-out region, or onto a side-wall of the cavity of the cut-out region. Alternatively, the method may further comprise forming a flexible circuit layer in a shape slightly larger than the cut-out region and positioning the flexible circuit layer between two substantially planar flexible substrates. The method may further comprise adhesively and / or thermally bonding the two substantially planar flexible substrates to one another to sandwich the flexible circuit therebetween.

[0155] The catheters described herein can be used in a variety of methods, for example, for mapping and ablating cardiac tissue.

[0156] Features which are described in the context of separate aspects of the invention may be used together and / or be interchangeable. Similarly, features described in the context of a single embodiment may also be provided separately or in any suitable sub-combination.BRIEF DESCRIPTION OF THE DRAWINGS

[0157] The invention is further illustrated with reference to the following figures in which:

[0158] Fig. 1 A is an isometric view of a catheter in a deployed configuration according to a first aspect of the invention.

[0159] Fig. IB is an in-plane view of a catheter of Fig. 1A.

[0160] Fig. 1C is an exploded perspective view of the distal end of the catheter of Fig. 1A.

[0161] Fig. 2A is an in-plane view of a catheter in a deployed configuration according to a second aspect of the invention.

[0162] Fig. 2B is an end-on view of a catheter of Fig. 2A.

[0163] Fig. 2C is a perspective view of the flexible tip of the catheter of Fig. 2A.

[0164] Fig. 2D is a system comprising a catheter of Fig. 2A.

[0165] Figs. 3 A and 3B are perspective views of the flexible tip of an alternative catheter in a deployed configuration according to a first aspect of the invention.

[0166] Fig. 3C is an in-plane view of the flexible tip of the catheter of Fig. 3A.

[0167] Figs. 4A and 4B are cross-section views of the electrode-carrying arms or flexible struts including alternative flexible circuit arrangements.

[0168] Fig. 4C is an isometric view of a flexible strut or electrode-carrying arm include a flexible circuit with an alternative arrangement.

[0169] Fig. 5 is an isometric view of a catheter in a deployed configuration according to a third aspect of the invention.

[0170] Fig. 6A is a perspective view of a distal end of a catheter having an expandable electrode assembly, according to a fourth aspect of the invention.

[0171] Fig. 6B is a perspective view of a distal end of an alternative catheter having an expandable electrode assembly, according to a fourth aspect of the invention in a second deployed configuration.

[0172] Fig. 7A is an isometric view of a catheter in a deployed configuration according to a first aspect of the invention and comprising additional flexible frameworks.

[0173] Fig. 7B is a side view of the catheter of Fig. 7A.

[0174] Figs. 8A, 8B and 8C are isometric views of alternative catheters in a deployed configuration according to a first aspect of the invention and comprising additional flexible frameworks.

[0175] Fig. 9A is a perspective view of a bottom (proximal) surface of the flexible tip portion of a catheter in a deployed configuration according to a fifth aspect of the invention.

[0176] Fig. 9B is a perspective view of a top (distal-most, tissue-contacting) surface of the flexible tip portion of a catheter in a deployed configuration according to a fifth aspect of the invention.

[0177] Fig. 9C is a perspective view of a top surface of a single substantially planar flexible substrate of the catheter of Figs. 9A and 8B.

[0178] Figs. 10A and 10B are perspective views of the flexible tip portion of a catheter in a deployed configuration according to an alternative fifth aspect of the invention. Fig. 10A is a bottom (proximal-most) surface and Fig. 1 OB is a top (distal -most, tissue-contacting) surface of the flexible tip portion.

[0179] Fig. 11 depicts an alternative flexible tip portion 20, in accordance with a fifth aspect of the invention.

[0180] Fig. 12 depicts an alternative flexible tip portion 20, in accordance with a fifth aspect of the invention.

[0181] Figs. 13A, 13B, and 13C depict an alternative flexible tip portion 20, in accordance with a fifth aspect of the invention. Figs. 13 A and 13B are perspective views of the flexible tip portion of a catheter in a deployed configuration according to an alternative fifth aspect of the invention. Fig. 13 A is a bottom surface and Fig. 13B is a top (distal -most, tissuecontacting) surface of the flexible tip portion. Fig. 13C is a close up of the bottom surface of a portion of the catheter of Figs. 13 A and 13B.

[0182] Figs. 14A, 14B, and 14C are an illustration of a method of deployment of a catheter of Fig. 9A. Fig. 14A shows the catheter in a second deployed configuration and Figs. 14B and 14C shows the catheter in a delivery configuration.

[0183] Fig. 15 illustrates an example medical device localization and navigation system that can be employed in conjunction with catheters of the present disclosure.DETAILED DESCRIPTION OF THE INVENTION

[0184] In the following description, various aspects of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the invention. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the aspect being described. The present invention will now be further elaborated by reference to the figures which are non-limiting.

[0185] Fig. 1 A is an isometric view of a flexible tip portion 20 of a catheter 10 according to a first aspect of the invention and Fig. IB is a side in-plane view of the flexible tip portion 20 of the catheter 10 in the plane of the flexible framework 22 in the deployed configuration. The catheter 10 comprises a catheter shaft 110 comprising a proximal end 120 (not shown) and a distal end 140, the catheter shaft defining a catheter shaft longitudinal axis L. A proximal coupler 70 is located at the distal end 140 of the catheter shaft. A flexible tip portion 20 extends distally from the distal end 140 of the catheter shaft. The flexible tip portion 20 comprises a flexible framework 22 comprising four electrode-carrying arms 24, where proximal ends 242 of the electrode-carrying arms extend proximally through the proximal coupler 70 and into the distal end 140 of the catheter shaft. The plurality of electrode-carrying arms 24 extend distally from the proximal coupler 70.

[0186] Each electrode-carrying arm 24 converges with at least one other of the plurality of electrode-carrying arms 24 at a distal end 26 of the flexible tip portion. Specifically, the electrode-carrying arms 24 include a first outboard arm 23, a second outboard arm 25, a first inboard arm 27 and a second inboard arm 29. A distal end of the first outboard arm 23 is connected with a distal end of the second outboard arm 25. A distal end of the first inboard arm 27 is connected with a distal end of the second inboard arm 29. The connected portion of the first and second inboard arms 27, 29, and the first and second outboard arms 23, 25 are coupled together at a distal end 26 of the flexible tip portion.

[0187] A plurality of electrodes 60, which are ring electrodes, are mounted on the electrode-carrying arms 24 and form a flexible, planar array of electrodes.

[0188] Each of the four electrode-carrying arms 24 comprises a shape memory material to predispose the flexible framework 22 into a plane. The plane is disposed at an angle a to the longitudinal axis L of the catheter shaft in the deployed configuration. As shown in Fig. IB, the angle is slightly greater than 90 degrees.

[0189] Fig. 1C is an exploded perspective view of the distal end 140 of the catheter of Fig.1A. Fig. 1C shows the proximal ends 242 of the electrode-carrying arms 24 extend proximally through the proximal coupler 70 and into the distal end 140 of the catheter shaft. The plurality of electrode-carrying arms 24 extend distally from the proximal coupler 70. Multiple irrigation holes 72 are located at the distal end of the proximal coupler 70.

[0190] Fig. 2A is an in-plane view of a flexible tip portion 20 of a catheter according to a second aspect of the invention in the deployed configuration, while Fig. 2B is an end view ofthe same flexible tip 20 and Fig. 2C is a perspective view of the same flexible tip 20. An intermediate portion 30 is positioned between the distal end 140 of the catheter shaft and the flexible tip portion 20. The intermediate portion 30 comprises a shape memory material predisposed into at least a partial loop disposed in a plane orthogonal to the catheter shaft longitudinal axis L. A flexible tip portion 20 comprises a flexible framework 22 comprising four electrode-carrying arms 24. A proximal coupler 70 is located at the distal end 34 of the intermediate portion. The four electrode-carrying arms 24 extend distally from the proximal coupler 70 located at the distal end 34 of the intermediate portion.

[0191] The flexible framework 22 is disposed at a distal end 34 of the intermediate portion. The plane of the flexible framework 22 is disposed at angle a to the longitudinal axis L of the catheter shaft in the deployed configuration. As shown in Figs. 2A and 2C, the angle is slightly greater than 90 degrees.

[0192] Fig. 2D is a catheter 10 having a flexible tip portion 20 according to a second aspect of the invention, and system for delivery. The catheter 10 further comprises a handle 100.

[0193] Figs. 3 A and 3B are perspective views of the flexible tip 20 of an alternative catheter 10 in a deployed configuration according to a first aspect of the invention. Fig. 3C is an in-plane view of the flexible tip 20 of the catheter of Fig. 3 A. The catheter 10 comprises a catheter shaft 110 comprising a proximal end 120 (not shown) and a distal end 140, the catheter shaft defining a catheter shaft longitudinal axis L. A proximal coupler 70 is located at the distal end 140 of the catheter shaft. A flexible tip portion 20 extends distally from the distal end 140 of the catheter shaft. The flexible tip portion 20 comprises a flexible framework 22 comprising two electrode-carrying arms 24, where proximal ends 242 of the electrode-carrying arms extend proximally through the proximal coupler 70 and into the distal end 140 of the catheter shaft. The plurality of electrode-carrying arms 24 extend distally from the proximal coupler 70.

[0194] Each electrode-carrying arm 24 converges with at least one other of the plurality of electrode-carrying arms 24 at a distal end 26 of the flexible tip portion. A plurality of electrodes 60, which are ring electrodes, are disposed on the electrode-carrying arms 24 and form a flexible array of electrodes. Each of the two electrode-carrying arms 24 comprises a shape memory material to predispose the flexible framework 22 into a plane. A proximal portion of the plane is substantially parallel with the longitudinal axis L of the catheter shaft in the deployed configuration and a distal portion of the plane of the flexible framework isdisposed at an angle a to the longitudinal axis L of the catheter shaft in the deployed configuration. As shown in Fig. 3 A, the angle is slightly greater than 90 degrees. The plane of the flexible framework 22 includes a bend such that the flexible tip portion 20 can be used with both a sweeping and a “push” mechanism.

[0195] Figs. 4A and 4B are cross-section views of the electrode-carrying arms 24 or flexible struts 40 including alternative flexible circuit arrangements. As discussed herein, flexible circuits may be applied to the electrode-carrying arms 24 or flexible struts 40. In Fig.4A, a polymeric substrate 404 having an upper surface and an opposed lower surface, is applied over a portion of the curved circumferential surface of the electrode-carrying arm 24 or flexible strut 40. In Fig. 4B, a polymeric substrate 404 having an upper surface and an opposed lower surface, is deposited over the entire surface of the electrode-carrying arm 24 or flexible strut 40, surrounding the electrode-carrying arm 24 or flexible strut 40. In the arrangement in Fig. 4B, a polymeric tube 280 may be configured to form the polymeric substrate 404 of the flexible circuit. A plurality of conductive traces 412 are embedded within the polymeric substrate 280, 404. That is, the one or more conductive traces lie between the upper and opposed lower surfaces of the polymeric substrate 280, 404. The conductive traces 412 are in electrical communication with the electrodes 60 (not shown).

[0196] Fig. 4C is an isometric view of a flexible strut 40 or electrode-carrying arm 24 including a flexible circuit with an alternative arrangement. A flexible circuit is wrapped in a spiral manner around the flexible strut 40 or electrode-carrying arm 24. The flexible circuit comprises a polymeric substrate 404 having an upper surface and an opposed lower surface, and a plurality of conductive traces 412 disposed over at least a portion of the upper surface of the polymeric substrate 404.

[0197] Fig. 5 is an isometric view of a flexible tip portion 20 of a catheter according to a third aspect of the invention in the deployed configuration. The flexible tip portion 20 includes a flexible framework 22 having a quadrilateral-shaped substantially planar flexible substrate 44 in a deployed configuration. A plurality of electrodes 60 are patterned on to the top surface 45 and bottom surface 46 of the substrate 44. The electrodes 60 form a regular square grid array on each surface 45, 46. Four flexible struts 40 are coupled between the distal end 140 of the catheter shaft and the flexible substrate 44. Each of the four flexible struts 40 comprises a shape memory material formed into a ‘stretched’ S-shape. The four flexible struts 40 are configured to hold the plane of the substantially planar flexible substrate44 at 90 degrees to the longitudinal axis L of the catheter shaft in the deployed configuration. A proximal coupler 70 is located at the distal end 140 of the catheter shaft. The four struts 40 extend distally from the proximal coupler 70, with the proximal end 42 of each strut emerging from the proximal coupler 70. Each flexible strut 40 forms a 45-degree angle with the longitudinal axis of the catheter shaft (the “expansion angle”, P). The distal end 43 of each strut is coupled to the flexible substrate 44, near the comers of the flexible substrate 44. A conductive trace 412 is attached to one of the flexible stmts 40 and is electrically coupled to the electrodes 60 on the substantially planar flexible substrate 44.

[0198] Fig. 6A depicts a perspective view of an expandable electrode assembly, in accordance with a fourth aspect of the invention in a second deployed configuration. The expandable electrode assembly 500 is coupled to the distal end 140 of the elongate catheter shaft 110. The elongate catheter shaft 110 defines a longitudinal axis L. The expandable assembly 500 includes a balloon member 504 having a top surface 506, a bottom surface 506, and an interior cavity 520 (not shown). The balloon member 504 is in the second deployed configuration where the balloon member 504 has a substantially flat shape.

[0199] A top flexible framework 502 (not shown) is disposed between an outer facing layer and an inner facing layer of the top surface 506 of the balloon member 504. A bottom flexible framework 503 (not shown) is disposed between an outer facing layer and an inner facing layer of the bottom surface 508 of the balloon member 504. A first plurality of electrodes 560 are patterned onto the top flexible framework 502. Each of the first plurality of electrodes 560 are arranged in horizontal rows 518 relative to the longitudinal axis L defined by the catheter shaft 110. The horizontal rows 518 are offset such that each electrode of the first plurality of electrodes 560 is offset from a respective electrode in an adjacent row. For example, each electrode in a horizontal row 518 may be equally spaced between two electrodes in an adjacent horizontal row 518. A second plurality of electrodes 560 are similarly patterned onto the bottom flexible framework 503. The first plurality of electrodes 560 and the second plurality of electrodes 560 do not align with each other.

[0200] A plurality of conductive traces 512 are disposed on each of the flexible frameworks 502, 503 of the expandable electrode assembly. The plurality of conductive traces 512 on each of the flexible frameworks 502, 503 are electrically coupled with a respective one of the first plurality of electrodes 560 and the second plurality of electrodes 560. It should be noted that not all of the plurality of conductive traces 512 are shown in Fig.6B for simplicity although the plurality of conductive traces 512 would electrically couple to each of the electrodes in practice. Further details of this arrangement can be found in U.S. Provisional Patent Application Nos. 63 / 448,625 filed 27 February 2023, and 63 / 603,451 filed 28 November 2023.

[0201] A flexible structural element 524 is disposed between the top flexible framework 506 and the bottom flexible framework 508. The flexible structural element 524 further includes four arms, a first outboard arm 523, a second outboard arm 525, a first inboard arm 527 and a second inboard arm 529. Each arm 523, 525, 527, 529 converges with at least one other of the arms at a distal end of the expandable assembly. Specifically, a distal end of the first outboard arm 523 is connected with a distal end of the second outboard arm 525. A distal end of the first inboard arm 527 is connected with a distal end of the second inboard arm 529. The flexible structural element 524 is disposed within the interior cavity 520 of the balloon member and functions as a bent transition between the catheter shaft and the balloon 504 with its plane disposed at 80 to 130 degrees to the longitudinal axis L of the catheter shaft. That is, the flexible structural element 524 is configured to position the balloon member 504 into a plane 80 to 130 degrees to the longitudinal axis L of the catheter shaft 110. The flexible structural element 524 may additionally provide rigidity and prevent kinking of the balloon member 304 when the balloon member 304 is deployed in a patient.

[0202] Fig. 6B depicts a perspective view of an alternative expandable electrode assembly, in accordance with a fourth aspect of the invention in a second deployed configuration. The expandable electrode assembly 500 is coupled to the distal end 140 of the elongate catheter shaft 110. The elongate catheter shaft 110 defines a longitudinal axis L. The expandable assembly 500 includes a balloon member 504 having a top surface 506, a bottom surface 506, and an interior cavity 520 (not shown). Each of the top surface 506 and the bottom surface 508 of the balloon member includes a plurality of apertures 510. The balloon member 504 is in the second deployed configuration where the balloon member 504 has a substantially flat shape.

[0203] A plurality of electrodes 560 extend within and are exposed through the top surface 506 and the bottom surface 508 of the balloon member. A first plurality of electrodes 560 may extend within and be exposed through the top surface 506 and a second plurality of electrodes 560 (not shown) may extend within and be exposed through the bottom surface

[0204] A top flexible framework 502 (not shown) is disposed between an outer facing layer and an inner facing layer of the top surface 506 of the balloon member. A bottom flexible framework 503 (not shown) is disposed between an outer facing layer and an inner facing layer of the bottom surface 508 of the balloon member. A plurality of conductive traces 512 are disposed on each of the flexible frameworks 502, 503 of the expandable electrode assembly. The plurality of conductive traces 512 on each of the flexible frameworks 502, 503 are electrically coupled with a respective one of the first plurality of electrodes 560 and the second plurality of electrodes 560. It should be noted that not all of the plurality of conductive traces 512 are shown in Fig. 6B for simplicity although the plurality of conductive traces 512 would electrically couple to each of the electrodes in practice.

[0205] A flexible structural element 524 is disposed between the top flexible framework 506 and the bottom flexible framework 508. The flexible structural element 524 is disposed within the interior cavity 520 of the balloon member and functions as a bent transition between the catheter shaft and the balloon 504 with its plane disposed at 80 to 130 degrees to the longitudinal axis L of the catheter shaft. That is, the flexible structural element 524 is configured to position the balloon member 504 into a plane 80 to 130 degrees to the longitudinal axis L of the catheter shaft 110. The flexible structural element 524 may additionally provide rigidity and prevent kinking of the balloon member 304 when the balloon member 304 is deployed in a patient.

[0206] Fig. 7A is an isometric view of a catheter 10 according to a first aspect of the invention and Fig. 7B is a side view of the catheter 10. The catheter 10 comprises a catheter shaft 110 comprising a proximal end 120 (not shown) and a distal end 140, the catheter shaft defining a catheter shaft longitudinal axis L. A proximal coupler 70 is located at the distal end 140 of the catheter shaft. A flexible tip portion 20 extends distally from the distal end 140 of the catheter shaft. The flexible tip portion 20 comprises a first flexible framework 22 comprising two electrode-carrying arms 24, where proximal ends 242 of the electrodecarrying arms (not shown) extend proximally through the proximal coupler 70 and into the distal end 140 of the catheter shaft. The plurality of electrode-carrying arms 24 extend distally from the proximal coupler 70.

[0207] Each electrode-carrying arm 24 converges with one other electrode-carrying arm 24 at a distal end of the first flexible framework 22. A plurality of electrodes 60, which are ringelectrodes, are mounted on the electrode-carrying arms 24 and form a flexible, planar array of electrodes. The electrodes 60 have a regular spacing.

[0208] The catheter 10 further comprises two additional flexible frameworks 22’, 22”. Each of the additional flexible frameworks 22’, 22” comprises two electrode-carrying arms 24’, 24”. A plurality of electrodes 60’, 60”, which are ring electrodes, are mounted on the electrode-carrying arms 24’, 24” and form a flexible, planar array of electrodes.

[0209] Each of the electrode-carrying arms 24, 24’, 24” comprises a shape memory material to predispose the flexible framework 22, 22’, 22” into a plane. The plane is disposed at an angle a to the longitudinal axis L of the catheter shaft in the deployed configuration. As shown in Fig. 7B, the angle is slightly greater than 90 degrees.

[0210] The flexible frameworks 22, 22’, 22” are distributed around the distal end 140 of the catheter shaft 110, specifically around the central (longitudinal) axis L of the catheter shaft. The flexible frameworks 22, 22’, 22” are spaced evenly around one side of the distal end 140 of the catheter shaft. That is, a proximal portion of each of the flexible frameworks 22, 22’, 22” is spaced from one another to create a central angle 9 of 90 degrees.

[0211] Figs. 8 A, 8B and 8C are isometric views of alternative catheters 10 according to a first aspect of the invention comprising one additional flexible framework. A flexible tip portion 20 extends distally from the distal end 140 of the catheter shaft. The flexible tip portion 20 comprises a first flexible framework 22 comprising a single electrode-carrying arms 24, where the electrode-carrying arms extend proximally through a proximal coupler 70 and into the distal end 140 of the catheter shaft. The electrode-carrying arm 24 extends distally from the proximal coupler 70.

[0212] Each catheter 10 comprises a second flexible framework 22’. The second flexible framework 22’ comprises a single electrode-carrying arm 24’. Each of the electrode-carrying arms 24, 24’ comprises a shape memory material to predispose the flexible framework 22, 22’ into a plane. The plane is disposed at an angle a to the longitudinal axis L of the catheter shaft in the deployed configuration. The shape memory material of the electrode-carrying arms 24, 24’ is bent into a multi -bend loop with bend angles of 90 degrees. In each of Figs.8A, 8B and 8C, the electrode-carrying arm 24, 24’ is bent to form a rectangular shape. It will be appreciated that any bend angle which achieves a bent framework shape would be suitable. Although sharp bends are illustrated, softer bends may be envisaged (i.e. with a greater radius of curvature). A plurality of electrodes 60, 60’ are mounted on each of theelectrode-carrying arm 24, 24’ and the bent electrode-carrying arms 24, 24’ act to align the electrodes 60, 60’ to form a flexible, planar array of electrodes.

[0213] The two flexible frameworks 22, 22’ are distributed evenly around the distal end of the catheter shaft. The two flexible frameworks 22, 22’ are disposed opposite each other on either side of the distal end of the catheter shaft. In Figs. 8A and 8B, the two flexible frameworks 22, 22’ are arranged to form a H-shape from the electrode-carrying arms 24, 24’, while in Fig. 8C, the two flexible frameworks 22, 22’ are arranged to form an I-shape. The electrodes 60, 60’ in Figs. 8A and 8B are arranged in a 4 by 4 grid array. The spacing S between adjacent electrodes 60 on one arm 24 is the same as the spacing S between electrodes 60 on adjacent branches of the same arm 24 and between aligned electrodes 60’ on an adjacent branch of arm 24’ of the other flexible framework 22’.

[0214] In Fig. 8C, electrodes 60, 60’ are arranged in an 8 by 2 grid array. The electrodes 60, 60’ in Figs. 8A and 8C are spot electrodes. The spot electrodes 60, 60’ may be manufactured by printing directly onto the shape memory material electrode-carrying arms 24, 24’.

[0215] The electrodes 60, 60’ in Fig. 8B are ring electrodes. A polymeric tube 280 is disposed over the shape memory material electrode-carrying arms 24,24’. The polymeric tube 280 is thermally secured to at least a portion of each of the plurality of electrode-carrying arms 24,24’. The electrodes 60, 60’ are mounted on the polymeric tube 280. The flexible tip portion 20 in Fig. 8B includes a plurality of flexible circuits 610 (not shown). Conductive traces are embedded within the polymeric tube 280 and are in electrical communication with the electrodes 60, 60’.

[0216] Fig. 9 depicts a perspective view of an alternative flexible tip portion 20, in accordance with a fifth aspect of the invention, in a second deployed configuration. The flexible tip portion 20 includes a flexible framework 22 comprising four substantially planar petal-shaped flexible substrates 84. The substantially planar flexible substrates 84 are evenly distributed around the distal end 140 of the catheter shaft. In the second configuration, the four substantially planar flexible petal-shaped substrates 84 form an open flower shape. A distal hub 81 is located at the distal end of the catheter shaft and central to the substantially planar flexible substrates 84, as shown in Fig. 9B. The petal-shaped substrates 84 are elliptical in shape, i.e. defined by an oval shape with no tip. Each substantially planar petalshaped flexible substrate 84 has a top surface 85 and a bottom surface 86. Each substantiallyplanar petal-shaped flexible substrate 84 has a free distal end 87 and a proximal end 88 that is affixed to the distal end 140 of the catheter shaft. Each of the flexible petal-shaped substrates 84 is adapted to transition between a first delivery configuration (not shown) to a second deployed configuration (Figs. 9A / 9B) wherein the free distal end 87 of each flexible petalshaped substrate is positioned radially outwardly from the proximal end 88 and the plane of each substantially planar flexible substrate 84 defines an angle a to the longitudinal axis L of the catheter shaft, where the angle a is 80 to 130 degrees. Each substantially planar flexible substrate is made from a planar nitinol sheet. The nitinol of the entire top surface 85 of each of the substantially planar flexible substrates is configured to form an ablation electrode 65. Diametrically opposite ablation electrodes 65 on the tissue-contacting surface may have the same polarity. The distal hub 81 comprises a distal hub electrode 69 located at the distal hub. The distal hub electrode 69 can be independently and selectively energized to have the same or different polarity as one or more of the nitinol ablation electrodes 65. The distal hub electrode may be independently and selectively energized to have the opposite polarity as the first electrode band on each substantially planar petal-shaped flexible substrate 84 (the proximal electrode band).

[0217] As shown in Fig. 9A, the flexible tip portion 20 further comprises a plurality of electrodes 60 mounted on the bottom surface 86 (non-tissue-contacting surface) of the substantially planar petal-shaped flexible substrates 84. A flexible circuit 83 is mounted on the bottom surface 86 of each of the substantially planar petal-shaped flexible substrates 84. The flexible circuit 83 comprises a plurality of conductive traces (not shown) electrically coupled with a respective one of the plurality of electrodes 60. A nonconductive material 91 is disposed between each of the plurality of conductive traces and the substantially planar flexible substrates 84. The nonconductive material also covers an outer facing surface of each of the plurality of conductive traces. Each electrode 60 of the plurality of electrodes is configured as a band on the bottom surface 86 of the substantially planar petal-shaped flexible substrate. A row of three longitudinally-aligned electrode bands 60 is distributed along each of the substantially planar petal-shaped flexible substrates 84. The electrode bands 60 may be equally spaced, and each electrode band may be of the same width. Adjacent electrode bands 60 can be selectively energized to be of opposite polarity. The electrode bands 60 can be configured as mapping electrodes.

[0218] Fig. 9C is a perspective view of a top surface 85 of a single substantially planar flexible substrates of the catheter of Figs. 9A and 9B. A protective coating 89 is providedaround the perimeter of each of the substantially planar petal-shaped flexible substrates 84. The protective coating 89 may surround the perimeter or outer edge of each of the substantially planar petal-shaped flexible substrates 84. The protective coating 89 protects the perimeter (edges or margins) of the substantially planar petal-shaped flexible substrates 84.

[0219] Figs. 10A and 10B are end-on views of the flexible tip portion 20 of a catheter in a deployed configuration according to an alternative fifth aspect of the invention. Fig. 10A is a bottom (proximal-most) surface and Fig. 1 OB is a top (distal -most, tissue-contacting) surface of the flexible tip portion. As for Fig. 9, the flexible tip portion 20 includes a flexible framework 22 comprising four substantially planar petal-shaped flexible substrates 84. The substantially planar petal-shaped flexible substrates 84 are evenly distributed around the distal end 140 of the catheter shaft. In the second configuration, the four substantially planar flexible petal-shaped substrates 84 form an open flower shape. The flexible tip portion 20 further comprises a plurality of electrodes 60 mounted on the bottom surface 86 and the top surface 85 of the substantially planar petal-shaped flexible substrates 84. A flexible circuit 83 is mounted on the bottom surface 86 and the top surface 85 of each of the substantially planar petal-shaped flexible substrates 84. A row of three longitudinally-aligned equally spaced electrode bands 60 is distributed along each of the substantially planar petal-shaped flexible substrates 84. Adjacent electrode bands 60 can be selectively energized to be of opposite polarity. The electrode bands 60 can be configured as mapping or ablation electrodes. The distal hub 81 on the tissue-contacting surface comprises a distal hub electrode 69 located at the distal hub, as shown in Fig. 10B. The distal hub electrode 69 can be independently and selectively energized to have the opposite polarity from the first electrode band 60 on each substantially planar flexible substrate (the proximal electrode band). Electrode bands 60 on the top surface 85 and bottom surface 86 have the same polarity, but may be energized to have different polarities.

[0220] Figs. 11 and 12 depict alternative shapes suitable for the substantially planar petalshaped flexible substrates 84 of a flexible tip portion 20, in accordance with a fifth aspect of the invention (as described with reference to Fig. 9). The flexible tip portion 20 includes a flexible framework 22 comprising four substantially planar petal-shaped flexible substrates 84. The substantially planar flexible substrates 84 are evenly distributed around the distal end 140 of the catheter shaft. In the second configuration, the four substantially planar flexible petal-shaped substrates 84 form an open flower shape. A distal hub 81 is located at the distal end 140 of the catheter shaft and central to the substantially planar flexible substrates 84. InFig. 11, the petal-shaped substrates 84 are obovate in shape, i.e. egg-shaped having a proximal end 88 which is narrower than the distal end 87, and generally broad. In Fig. 12, the petal-shaped substrates 84 are elliptical in shape and include a cut-out region 90 located in a proximal section of the substantially planar flexible substate 84, adjacent the distal hub 81. Inside the cut-out region a substantially planar flexible circuit 83 is located. The substantially planar flexible circuit layer 83 may be sandwiched between two substantially planar flexible substrates 84. The flexible circuit 83 of each substrate 84 includes six electrodes 60 and nonconductive material 91. A steering ring 92 surrounds the catheter shaft and is located as close to the distal end 140 of the catheter shaft as possible, for example, adjacent the flexible tip portion 20.

[0221] Fig. 13 depicts a further alternative shape suitable for the substantially planar flexible substrates 84 of a flexible tip portion 20, in accordance with a fifth aspect of the invention (as described with reference to Fig. 9). The flexible tip portion 20 includes a flexible framework 22 comprising four substantially planar flexible substrates 84. The substantially planar flexible substrates 84 are evenly distributed around the distal end 140 of the catheter shaft. A distal hub 81 is located at the distal end 140 of the catheter shaft and central to the substantially planar flexible substrates 84. In Fig. 13, the substrates 84 are substantially shaped like an anvil or a curved T-shape, with the top of the T at the free distal end 87 and the shaft of the T extending proximally. A curved T-shape has rounded edges. The top of the T (free distal end 87) may have a width of 3 to 5mm, the shaft of the T may have a length of 4 to 8mm. The distal hub 81 may have a diameter of 5mm. Other dimensions are envisaged. A protective coating 89 is provided around the perimeter of each of the substantially planar T-shaped flexible substrates 84. The protective coating 89 may surround the perimeter or outer edge of each of the substantially planar T-shaped flexible substrates.

[0222] The tissue-contacting surface of the flexible tip portion 20 is illustrated in Fig. 13B.Each substantially planar T-shaped flexible substrate 84 has a top surface 85 (illustrated in Fig. 13B). Each substantially planar T-shaped flexible substrate 84 has a free distal end 87 and a proximal end 88 that is affixed to the distal end 140 of the catheter shaft. Each substantially planar flexible substrate is made from a planar nitinol sheet. The nitinol of the entire top surface 85 of each of petal is configured to form an ablation electrode 65. As illustrated in Fig. 13B, all ablation electrodes 65 may have the same polarity. The distal hub 81 comprises a distal hub electrode 69 located at the distal hub. The distal hub electrode 69can be independently and selectively energized to have the opposite polarity as the nitinol ablation electrodes 65. The distal hub electrode 69 can be configured as an ablation electrode.

[0223] The bottom non-tissue-contacting surface of the flexible tip portion 20 is illustrated in Figs. 13A and 13C. In Fig. 13C, the protective coating 89 is removed so that the layered structure can be seen. As shown in Figs. 13A and 13C, the flexible tip portion 20 further comprises four T-shaped substrates 84 which include a cut-out region 90. These T-shaped substrates 84 are on the bottom non-tissue contacting surface and are adhesively or thermally bonded to the T-shaped substrates that form the tissue-contacting surface. Inside the cut-out region a substantially planar flexible circuit 83 is located. The substantially planar flexible circuit layer 83 is sandwiched between the two substantially planar flexible substrates 84. Four electrodes 60 are mounted on the bottom surface 86 of each of the substantially planar T-shaped flexible substrates 84 and can be configured as mapping or ablation electrodes, preferably mapping electrodes. The four electrodes 60 are part of the flexible circuit 83. Additionally, two larger electrodes 63 are mounted on the bottom surface 86 of each of the substantially planar T-shaped flexible substrates 84 as part of the flexible circuit 83. The two larger electrodes 63 on the bottom surface 86 of each of the substantially planar T-shaped flexible substrates can be configured as ablation electrodes. The flexible circuit 83 comprises a plurality of conductive traces (not shown) electrically coupled with a respective one of the plurality of electrodes 60 and 63. A nonconductive material 91 is disposed between each of the plurality of conductive traces and the substantially planar flexible substrates 84. The nonconductive material 91 also covers an outer facing surface of each of the plurality of conductive traces. The nonconductive material 91 may also isolate the mapping electrodes 60 from the ablation electrodes 63. Three of the smaller (mapping) electrodes 60 are located near the distal end 87 of each of the substantially planar T-shaped flexible substrates 84, and one of the smaller electrode 60 is located near the proximal end 88 of each of the substantially planar T-shaped flexible substrates 84. As shown in Fig. 13B, a steering ring 92 is located as close to the distal end 140 of the catheter shaft as possible, for example, adjacent the flexible tip portion 20. In an alternative configuration, the top tissue-contacting surface and bottom non-tissue contacting surfaces could be reversed; Fig. 13B could represent the bottom nontissue contacting surface and Figs. 13A / C could represent the top tissue contacting surface. Further alternatively, the electrode / flexible circuit configuration of the bottom non-tissue contacting surface shown in Figs. 13 A and C could also be used as the top tissue-contactingsurface. In all configurations, the top tissue-contacting surface includes a central distal hub electrode 69.

[0224] Fig. 14 is an illustration of a method of deployment of a catheter of Fig. 9A. Fig. 14A shows the catheter in a second deployed configuration and Figs. 14B and 14C shows the catheter in a delivery configuration, with Fig. 14C showing an end-on perspective view. Each of the flexible petal-shaped substrates 84 is adapted to transition between a first delivery configuration (Figs. 14B, 14C) to a second deployed configuration (Fig. 14A) wherein the free distal end 87 of each flexible petal-shaped substrate is positioned radially outwardly from the proximal end 88 and the plane of each substantially planar flexible substrate defines an angle a, of 80 to 130 degrees, to the longitudinal axis L of the catheter shaft. The catheter further includes an introducer sheath 94, as shown in Figs. 14B and 14C. The flexible tip portion 20 is compressed to fit within the introducer sheath 94. The sheath 94 is configured for advancement over the flexible tip portion 20 to bring the substantially planar flexible substrates 94 into a first delivery configuration (Figs. 14B, 14C) and for retraction from the flexible tip portion 20 to bring the substantially planar flexible substrates 84 into a second deployed configuration (Fig. 14A).

[0225] A localization and navigation system may be provided for visualization, mapping and navigation of internal body structures. As shown in Figure 15, the electrodes 60, 60’, 60”, 63, 65, 69, 560 of the high-density catheter 10 are configured to be conformable to a tissue (e.g., cardiac tissue) to interface the electrodes 60, 60’, 60”, 63, 65, 69, 560 with the tissue. The configuration of the flexible tip portion 22, 22’, 22” or expandable assembly 500 and electrodes 60, 60’, 60”, 63, 65, 69, 560 discussed herein facilitates insertion of the flexible tip portion 22, 22’, 22” or expandable assembly 500 using a handle 110 of the catheter, deployment of the flexible tip portion 22, 22’, 22” or expandable assembly 500 and electrodes 60, 60’, 60”, 63, 65, 69, 560 within the heart 16, and withdrawal of the flexible tip portion 22, 22’, 22” or expandable assembly 500 from the patient 17. The electrodes 60, 60’, 60”, 63, 65, 69, 560 can be used to interface with the tissue as the flexible framework is advanced, or retracted to receive signals. The signals can be transmitted via the connector 56 to a system 108 for analyzing the signal e.g., to determine localization.

[0226] Figure 15 also illustrates a diagrammatic view of a medical device localization system 108 that can be used in conjunction with the high-density catheter 10. The system 108 includes a main electronic control unit 112 (e.g., a processor) having various input / outputmechanisms 114, a display 116, an electrocardiogram (ECG) monitor 118, a localization system, such as a localization and navigation system 122, and the high-density catheter 10. The high-density catheter 10 includes a plurality of electrodes 60, 60’, 60”, 63, 65, 69, 560 and a flexible tip portion 22, 22’, 22” or expandable assembly 500.

[0227] The input / output mechanisms 114 may include conventional apparatus for interfacing with a computer-based control unit including, for example, one or more of a keyboard, a mouse, a tablet, a foot pedal, a switch and / or the like. The display 116 may also comprise conventional apparatus, such as a computer monitor. The ECG monitor 118 is configured to continuously detect an electrical timing signal of the heart organ through the use of a plurality of ECG electrodes (not shown), which may be externally affixed to the outside of a patient’s body. The timing signal generally corresponds to a particular phase of the cardiac cycle, among other things. Generally, the ECG signal(s) may be used by the control unit 112 for ECG synchronized play-back of a previously captured sequence of images (cine loop). The ECG monitor 120 and ECG-electrodes may both include conventional components.

[0228] The localization and navigation system 122 may be configured to serve to determine position (localization) data with respect to the one or more location sensors and / or the electrodes 60, 60’, 60”, 63, 65, 69, 560 and output a respective location reading. The electrodes 60, 60’, 60”, 63, 65, 69, 560 can be individually electrically coupled to an ablation generator 124 (e.g., via suitable electrical wire or other suitable electrical conductors extending through the catheter shaft 110). The ablation generator 124 generates ablative energy which is delivered by the catheter 10 to the tissue, to form lesions in the tissue or cause electroporation, for example.

[0229] It will be appreciated that the terms “proximal” and “distal” may be used throughout the specification with reference to a clinician manipulating one end of an instrument used to treat a patient. The term “proximal” refers to the portion of the instrument closest to the clinician and the term “distal” refers to the portion located furthest from the clinician. It will be further appreciated that for conciseness and clarity, spatial terms such as “vertical,” “horizontal,” “up,” and “down” may be used herein with respect to the illustrated catheters. However, surgical instruments may be used in many orientations and positions, and these terms are not intended to be limiting and absolute.

[0230] Although the electrophysiology catheters and kits described herein mainly address electrophysiological procedures in patient heart (e.g., EA sensing and tissue ablation), the catheters, kits and systems described herein can also be used in other applications, such as in electrophysiological procedures carried out on other organs of a patient, and in electrophysiological procedures carried out in patient lung(s) and in treatment of renal denervation.

[0231] It will thus be appreciated that the electrophysiology catheters and kits described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.

[0232] Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the catheters as described in the specification and illustrated in the accompanying drawings. It will be understood by those skilled in the art, however, that the catheters may be practiced without such specific details. In other instances, well-known operations, components, and elements have not been described in detail so as not to obscure the catheters described in the specification. Those of ordinary skill in the art will understand that the catheters described and illustrated herein are non-limiting examples, and thus it can be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the disclosure, the scope of which is defined solely by the appended claims. The particular features, structures, or characteristics described herein for the catheters may be combined in any suitable manner.

[0233] It will be appreciated that any item, feature, parameter or component described herein may, where appropriate, relate to any of the aspects of the present disclosure.

[0234] The invention is defined in the appended claims. A non-exhaustive list of aspects of the invention set out in the numbered clauses is useful for understanding the invention:

[0235] Clause 1: A catheter comprising: a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; and a flexible tip portion extending from the distal end of the catheter shaft, the flexible tip portion comprising:a flexible framework comprising a plurality of electrode-carrying arms, wherein each electrode-carrying arm extends from a distal end of the catheter shaft, wherein each of the plurality of electrode-carrying arms converges with at least one other of the plurality of electrode-carrying arms at a distal end of the flexible framework; and a plurality of electrodes coupled to the electrode-carrying arms; wherein each of the plurality of electrode-carrying arms comprises a shape memory material to predispose the flexible framework into a plane, wherein at least a portion of the plane of the flexible framework is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration.

[0236] Clause 2: The catheter of clause 1, wherein the plane of the flexible framework is disposed at the angle in the range of 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration and the plurality of electrodes coupled to the electrodecarrying arms form a flexible, planar array of electrodes.

[0237] Clause 3: A catheter comprising: a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; and a flexible tip portion comprising: a flexible framework comprising a plurality of electrode-carrying arms, wherein each of the plurality of electrode-carrying arms converges with at least one other of the plurality of electrode-carrying arms at a distal end of the flexible framework, wherein each of the plurality of electrode-carrying arms comprises a shape memory material to predispose the flexible framework into a plane, wherein the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration; a plurality of electrodes coupled to the electrode-carrying arms; and an intermediate portion between the distal end of the catheter shaft and the flexible tip portion, the intermediate portion comprising a shape memory material predisposed into at least a partial loop disposed in a plane intersecting the catheter shaft longitudinal axis, and wherein the flexible framework is disposed at a distal end of the intermediate portion.

[0238] Clause 4: The catheter of clause 3, wherein the at least partial loop of the intermediate portion is disposed in a plane orthogonal to the catheter shaft longitudinal axis, wherein either a) each of the plurality of electrode-carrying arms extends from a distal end of the catheter shaft and through the intermediate portion, such that each arm is predisposed into the at least partial loop, or b) each of the plurality of electrode-carrying arms extends from a distal end of the intermediate portion.

[0239] Clause 5: The catheter of any preceding claim, further comprising a second flexible framework having a plurality of electrode-carrying arms, wherein each of the plurality of electrode-carrying arms comprises a shape memory material to predispose the second flexible framework into a second plane, wherein at least a portion of the second plane of the second flexible framework is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration.

[0240] Clause 6: The catheter of clause 5, wherein each of the flexible frameworks are distributed around the catheter shaft longitudinal axis and are evenly spaced around one side of the distal end of the catheter shaft.

[0241] Clause 7: The catheter of any preceding clause, wherein the flexible framework comprises at least two electrode-carrying arms, optionally at least four electrode-carrying arms, further optionally a first inboard arm, a second inboard arm, a first outboard arm, and a second outboard arm, and further optionally, a first midboard arm.

[0242] Clause 8: The catheter of any of clauses 2 to 7, wherein the plurality of electrodes coupled to the electrode-carrying arms forms a flexible, planar array of electrodes.

[0243] Clause 9: The catheter of any preceding clause, wherein the plurality of electrodes comprises a first array of electrodes patterned onto the plurality of electrode-carrying arms.

[0244] Clause 10: The catheter of clause 9, further comprising a second array of electrodes patterned onto the plurality of electrode-carrying arms, wherein the first array and second array of electrodes comprises a row of longitudinally-aligned electrodes aligned parallel to the electrode carrying arms, optionally, wherein the first array is arranged on a first side of the electrode-carrying arms and the second array is arranged on a second side of the electrode-carrying arms.

[0245] Clause 11 : The catheter of any preceding clause, wherein the plurality of electrodes are coupled to the plurality of electrode-carrying arms via a plating process.

[0246] Clause 12: The catheter of any of clauses 1 to 8, wherein the plurality of electrodes are ring electrodes.

[0247] Clause 13: The catheter of any preceding clause, further comprising a plurality of conductive traces disposed on the flexible tip portion, each of the plurality of conductive traces electrically coupled with a respective one of the plurality of electrodes.

[0248] Clause 14: The catheter of clause 13, further comprising a mounting portion connected to the plurality of electrode-carrying arms, wherein the mounting portion includes a plurality of contact pads electrically coupled with the plurality of electrodes via the plurality of conductive traces.

[0249] Clause 15: The catheter of any of clauses 13 or 14, further comprising a nonconductive material disposed between each of the plurality of conductive traces and the flexible tip portion, optionally, further comprising a nonconductive material disposed over an outward facing surface of each of the plurality of conductive traces.

[0250] Clause 16: The catheter of any one of clauses 13 to 15, wherein each of the plurality of conductive traces is aligned parallel to the axis of the respective electrode-carrying arm.

[0251] Clause 17: The catheter of any preceding clause, further comprising a plurality of tubular polymeric members, each tubular polymeric member comprising a first open end and an opposed second open end defining an open lumen therebetween, the tubular polymeric member comprising an inner member surface and an outer member surface, wherein at least one of the plurality of electrode-carrying arms is at least partially disposed within the lumen of said tubular polymeric member.

[0252] Clause 18: A method of manufacturing a catheter, the method comprising: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis; disposing shape memory material into a plurality of electrode-carrying arms and arranging at least a portion of each of the electrode-carrying arms into a single common plane to form a flexible framework; disposing the electrode-carrying arms at the distal end of the catheter shaft to form a flexible tip portion of the catheter and setting the shape of the flexible tip portion such that the plane of the flexible framework is predisposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; and securing the electrode-carrying arms to the distal end of the catheter shaft.

[0253] Clause 19: The method of clause 18, further comprising coupling a plurality of electrodes on the plurality of electrode-carrying arms.

[0254] Clause 20: The method of clause 18 or 19, further comprising disposing a polymeric tube over the shape memory material electrode-carrying arms; wherein coupling the plurality of electrodes on the plurality of electrode-carrying arms comprises mounting the electrodes on the polymeric tube of each of the plurality of electrode-carrying arms.

[0255] Clause 21 : The method of clause 20, wherein the method further comprises annealing the framework comprising the polymeric tube, optionally wherein annealing takes place at a temperature of 82 to 105°C.

[0256] Clause 22: The method of clause 18 or 19, further comprising disposing an annealed polymeric tube over the shape memory material electrode-carrying arms; wherein coupling the plurality of electrodes on the plurality of electrode-carrying arms comprises mounting the electrodes on the polymeric tube of each of the plurality of electrode-carrying arms, optionally wherein the annealing of the polymeric tube takes place at a temperature of 82 to 105°C.

[0257] Clause 23: The method of any of clauses 18 to 22, wherein setting the shape of the flexible tip portion comprises: bending the shape memory material such that the plane of the flexible framework is at the angle in the range of 80 to 130 degrees to the longitudinal axis of the catheter shaft; fixing the shape of the flexible framework; and quenching the flexible framework.

[0258] Clause 24: The method of clause 23, wherein the fixing takes place at a temperature in a range of 490-540°C, optionally in a salt bath.

[0259] Clause 25: The method of clause 23 or 24, wherein the bending comprises a radius of curvature in a range of 3 to 5mm, preferably 3.81mm.

[0260] Clause 26: A method of manufacturing a catheter, the method comprising: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis; disposing shape memory material into an intermediate portion at a distal end of the catheter shaft and setting the shape memory material into at least a partial loop disposed in a plane, wherein the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; disposing a flexible framework comprising a plurality of electrode-carrying arms at the distal end of the intermediate portion, wherein each of the plurality of electrode-carrying arms converges with at least one other of the plurality of electrode-carrying arms at a distal end of the flexible framework, wherein the electrode-carrying arms of the flexible framework are arranged in-plane in a single common plane, such that the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; and securing the intermediate portion to the distal end of the catheter shaft.

[0261] Clause 27: The method of clause 26, wherein the plurality of electrode-carrying arms comprises a shape memory material and each electrode-carrying arm extends from the distal end of the catheter shaft and extends through the intermediate portion, wherein the setting the shape memory material into the at least partial loop includes setting the shape memory wire of the plurality of electrode-carrying arms into at least a partial loop as part of the intermediate portion.

[0262] Clause 28: The method of clause 26, wherein the disposing the flexible framework comprising the plurality of electrode-carrying arms at the distal end of the intermediate portion comprises securing each electrode-carrying arm to the distal end of the intermediate portion.

[0263] Clause 29: The method of any of clauses 26 to 28, further comprising coupling a plurality of electrodes on the plurality of electrode-carrying arms.

[0264] Clause 30: The method of clause 29, further comprising disposing a polymeric tube over the electrode-carrying arms; wherein coupling the plurality of electrodes on the plurality of electrode-carrying arms comprises mounting the electrodes on the polymeric tube of each of the plurality of electrode-carrying arms.

[0265] Clause 31 : A catheter comprising: a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; and a flexible tip portion comprising: a flexible framework comprising a substantially planar flexible substrate; a plurality of electrodes mounted on the flexible substrate; and a plurality of flexible struts coupled between the distal end of the catheter shaft and the flexible substrate, wherein each of the plurality of flexible struts comprise shape memory material configured to position the substantially planar flexible substrate in a plane that is at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration.

[0266] Clause 32: The catheter of clause 31, wherein the plurality of flexible struts are coupled to a perimeter of the flexible substrate.

[0267] Clause 33: The catheter of clause 31 or 32, wherein the plurality of flexible struts are each axially compressible to allow for reaction to applied forces while maintaining the flexible substrate in the plane at the angle in the range of 80 to 130 degrees to the longitudinal axis of the shaft.

[0268] Clause 34: The catheter of clauses 31 to 33, wherein the plurality of flexible struts each has a curved shape, optionally wherein the curved shape comprises a wave shape or a multi-curve shape, optionally a S-shape.

[0269] Clause 35: The catheter of clauses 31 to 34, wherein plurality of flexible struts are each coupled to the distal end of the catheter shaft at an expansion angle of about 30 to 60 degrees to the longitudinal axis of the catheter shaft, optionally at an expansion angle of about 45 degrees to the longitudinal axis of the catheter shaft.

[0270] Clause 36: The catheter of any of clauses 31 to 35, wherein the plurality of electrodes comprises a first array of electrodes patterned onto the substantially planar flexible substrate, wherein the first array of electrodes are arranged in a grid configuration.

[0271] Clause 37: The catheter of clause 31, wherein the substantially planar flexible substrate comprises a top surface and a bottom surface, the bottom surface being parallel with the top surface; wherein the plurality of electrodes comprises a second array of electrodes patterned onto the bottom surface of the substantially planar flexible substrate, wherein the second array of electrodes are arranged in a grid configuration; and wherein the first array of electrodes is patterned onto the top surface of the substantially planar flexible substrate, optionally wherein the first array of electrodes is aligned with the second array of electrodes.

[0272] Clause 38: The catheter of any of clauses 31 to 37, further comprising a plurality of conductive traces disposed on the substantially planar flexible substrate, each of the plurality of conductive traces electrically coupled with a respective one of the plurality of electrodes, optionally further comprising a non-conductive material disposed over an outward facing surface of the conductive traces.

[0273] Clause 39: A method of manufacturing a catheter, the method comprising: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis; disposing a shape memory material into a plurality of struts and setting the shape memory material of each of the plurality of struts into a curved shape; coupling a flexible framework comprising a substantially planar flexible substrate to the distal ends of each of the plurality of struts, wherein the flexible substrate is disposed in a plane that is at an angle in range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; and securing the plurality of struts to the distal end of the catheter shaft.

[0274] Clause 40: The method of clause 39, wherein the curved shape comprises a wave shape or a multi-curve shape, optionally a S-shape.

[0275] Clause 41 : The method of clause 39 or 40, wherein disposing the struts at the distal end of the catheter shaft comprises disposing the struts at an expansion angle of about 30 to 60 degrees to the longitudinal axis of the catheter shaft, optionally at an expansion angle of about 45 degrees to the longitudinal axis of the catheter shaft.

[0276] Clause 42: The method of any of clauses 39 to 41, wherein the substantially planar flexible substrate comprises a plurality of electrodes mounted or patterned on a top and / or bottom surface of the substrate.

[0277] Clause 43: The method of any of clauses 39 to 42, further comprising disposing a polymeric tube over the shape memory material struts.

[0278] Clause 44: The method of clause 43, wherein the method further comprises annealing the struts comprising the polymeric tube, optionally wherein annealing takes place at a temperature of 82 to 105°C.

[0279] Clause 45: The method of any of clauses 39 to 44, wherein setting the shape memory material of the plurality of struts comprises: bending the shape memory material into the curved shape; fixing the curved shape of the struts; and quenching the struts.

[0280] Clause 46: The method of clause 45, wherein the fixing takes place at a temperature in range of 490-540°C, optionally in a salt bath.

[0281] Clause 47: The method of any of clauses 39 to 46, wherein the coupling the flexible framework comprising the substantially planar flexible substrate to the distal ends of each of the plurality of struts comprises coupling the flexible struts to a portion of a perimeter of the flexible substrate.

[0282] Clause 48: A catheter comprising: a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; and an expandable assembly, wherein the expandable assembly comprises: a balloon member having a top surface, a bottom surface, and an interior cavity, each of the top surface and the bottom surface having an outer facing layer and an inner facing layer; a top flexible framework disposed between the outer facing layer and the inner facing layer of the top surface of the balloon member; a bottom flexible framework disposed between the outer facing layer andthe inner facing layer of the bottom surface of the balloon member; a first plurality of electrodes patterned onto the top flexible framework; a second plurality of electrodes patterned onto the bottom flexible framework, wherein the first plurality of electrodes are aligned with the second plurality of electrodes; a plurality of conductive traces disposed on each of the flexible frameworks, each of the plurality of conductive traces electrically coupled with a respective one of the first plurality of electrodes and the second plurality of electrodes; and a flexible structural element disposed within the interior cavity; wherein the expandable assembly comprises a first delivery configuration, a second deployed configuration, and an intermediate configuration between the first delivery configuration and the second deployed configuration, wherein, in the intermediate configuration, the balloon member is unconstrained from an introducer sheath and uninflated, and the balloon member has a substantially planar shape, and wherein the flexible structural element comprises a shape memory material to predispose the balloon member in a plane at an angle in a range from 80 to 130 degrees to the longitudinal axis of the shaft.

[0283] Clause 49: The catheter of clause 48, wherein the shape memory material flexible structural element is disposed between the top flexible framework and the bottom flexible framework.

[0284] Clause 50: The catheter of clause 48 or 49, wherein the balloon member has a substantially flat shape, concave shape, or convex shape in the second deployed configuration.

[0285] Clause 51: The catheter of any of clauses 48 to 50, wherein the balloon member comprises a plurality of apertures on the outer facing layer of the top surface and the bottom surface of the balloon member configured to expose the respective first plurality of electrodes and the second plurality of electrodes, optionally wherein a diameter of the plurality of apertures is the same size or smaller than a diameter of the respective first and second plurality of electrodes.

[0286] Clause 52: The catheter of any of clauses 48 to 51, wherein the flexible structural element is configured to inflate the balloon member in the second deployed configuration, or wherein the elongate catheter shaft comprises an inflation lumen coupled to the interior cavity of the balloon member, wherein the balloon member in the first delivery configuration is uninflated and in the second deployed configuration is inflated via a liquid or a gasdelivered through the inflation lumen, optionally wherein the inflation lumen is an oval inflation lumen.

[0287] Clause 53: The catheter of any of clauses 48 to 52, wherein each of the first plurality of electrodes and the second plurality of electrodes are arranged in horizontal rows relative to the longitudinal axis of the elongate catheter shaft, optionally wherein the horizontal rows are offset such that each electrode in each row is offset from a respective electrode in an adjacent row.

[0288] Clause 54: The catheter of any of clauses 48 to 53, wherein each of the first plurality of electrodes and the second plurality of electrodes are arranged in vertical rows parallel to the longitudinal axis of the elongate catheter shaft, wherein the vertical rows are offset such that each electrode in each row is offset from a respective electrode in an adjacent row.

[0289] Clause 55: A catheter comprising: a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; and a flexible tip portion comprising: a flexible framework comprising at least one substantially planar flexible substrate, wherein the at least one substantially planar flexible substrate is petal-shaped and comprises a top surface and a bottom surface, wherein the substantially planar flexible substrate has a free distal end and a proximal end that is coupled to the distal end of the catheter shaft; a plurality of electrodes coupled to the at least one substantially planar flexible substrate; and a distal hub located at the distal end of the catheter shaft; wherein the flexible petal-shaped substrate is adapted to transition between a first delivery configuration to a second deployed configuration wherein the free distal end of the flexible petal-shaped substrate is positioned radially outwardly from the proximal end and the substantially planar flexible substrate comprises shape memory material to predispose the flexible petal-shaped substate in a plane at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft.

[0290] Clause 56: The catheter of clause 55, wherein each of the substantially planar flexible substrates bows outwardly into the second deployed configuration.

[0291] Clause 57: The catheter of clause 55 or 56, wherein the flexible framework comprises two or more substantially planar flexible substrates and the substantially planar flexible substrates are evenly distributed around the distal end of the catheter shaft.

[0292] Clause 58: The catheter of any one of clauses 55 to 57, wherein the petal-shape of the or each substantially planar flexible substrate is selected from one of elliptical, truncate, obovate, ovate, lanceolate, or round.

[0293] Clause 59: The catheter of any one of clauses 55 to 58, wherein the shape memory material comprises nitinol and an entire top surface of each of the substantially planar flexible substrates is configured to form an ablation electrode.

[0294] Clause 60: The catheter of clause 59, wherein the plurality of electrodes are mounted on at least the bottom surface of the or each of the substantially planar flexible substrates.

[0295] Clause 61: The catheter of any one of clauses 55 to 58, wherein the plurality of electrodes are mounted on the bottom surface and the top surface of the or each of the substantially planar flexible substrates.

[0296] Clause 62: The catheter of any one of clauses 60 or 61, further comprising a flexible circuit mounted on at least the bottom surface of the or each of the substantially planar flexible substrates, or when dependent on clause 61, on the top and bottom surface of the or each of the substantially planar flexible substrates.

[0297] Clause 63: The catheter of any one of clauses 55 to 59, wherein the or each substantially planar flexible substrate further comprises at least one cut-out region.

[0298] Clause 64: The catheter of clause 63, further comprising a flexible circuit inside the cut-out region of the or each of the substantially planar flexible substrates, the flexible circuit coupled to the plurality of electrodes for mapping.

[0299] Clause 65: The catheter of clause 64, wherein the or each of the substantially planar flexible substrates comprise two layers of nitinol and wherein the cut-out region is formed in both layers of the nitinol, further comprising a flexible circuit layer positioned between the two nitinol layers and within the cut-out region, the flexible circuit coupled to the plurality of electrodes.

[0300] Clause 66: The catheter of any one of clauses 62, 64 or 65, wherein the flexible circuit comprises a plurality of conductive traces disposed on the flexible tip portion, each of the plurality of conductive traces electrically coupled with a respective one of the plurality of electrodes.

[0301] Clause 67: The catheter of clause 66, further comprising a mounting portion coupled to the substantially planar flexible substrates, wherein the mounting portion includes a plurality of contact pads electrically coupled with the plurality of conductive traces and configured to couple with the plurality of electrodes.

[0302] Clause 68: The catheter of any of clauses 66 or 67, further comprising a nonconductive material disposed between each of the plurality of conductive traces and the substantially planar flexible substrates, optionally, further comprising a nonconductive material disposed over an outward facing surface of each of the plurality of conductive traces.

[0303] Clause 69: The catheter of any of clauses 60 to 68, wherein each electrode of the plurality of electrodes is configured as a band on the bottom surface and / or the top surface of the substantially planar flexible substrate.

[0304] Clause 70: The catheter of any of clauses 60 to 68, wherein each electrode of the plurality of electrodes is deposited on the bottom surface and / or the top surface of the substantially planar flexible substrate.

[0305] Clause 71: The catheter of clause 70, wherein the plurality of electrodes comprise a first electrode arrangement configured for ablation, and / or a second electrode arrangement configured for mapping, wherein the first arrangement is larger than the second arrangement.

[0306] Clause 72: The catheter of clause 71, wherein the first electrode arrangement is located near the distal end of each of the substantially planar flexible substrates and the second electrode arrangement is located near the proximal end of each of the substantially planar flexible substrates.

[0307] Clause 73: The catheter of any of clauses 55 to 72, further comprising a protective coating around a perimeter of each of the substantially planar flexible substrates.

[0308] Clause 74: The catheter of clause 73, wherein the protective coating comprises a polymeric material.

[0309] Clause 75: The catheter of any of clauses 55 to 74, further comprising a distal hub electrode located at the distal hub.

[0310] Clause 76: The catheter of any of clauses 55 to 75, wherein the plurality of electrodes for mapping are electrically isolated and independently activated from the petalshaped substrate for ablation.

[0311] Clause 77: The catheter of any of clauses 55 to 76, further comprising a steering ring at or near the distal end of the catheter shaft.

[0312] Clause 78: The catheter of any of clauses 55 to 77, further comprising an introducer sheath configured for advancement over the flexible tip portion to bring the substantially planar flexible substrates into a first delivery configuration and for retraction from the flexible tip portion to bring the substantially planar flexible substrates into a second deployed configuration.

[0313] Clause 79: A method of manufacturing a catheter, the method comprising: forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis; forming a flexible framework comprising at least one substantially planar petal-shaped flexible substrate comprising nitinol; and coupling the flexible framework to the distal end of the catheter shaft such that a proximal end of the at least one substantially planar petal-shaped flexible substrate is coupled to the distal end of the catheter shaft and setting the nitinol of the flexible framework such that a plane of the at least one substantially planar petal-shaped flexible substrate defines an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft.

[0314] Clause 80: The method of clause 79, further comprising coupling a plurality of electrodes onto a top and / or bottom surface of the substantially planar flexible substrate.

[0315] Clause 81: The method of any of clauses 79 to 80, further comprising mounting at least one flexible circuit onto the top and / or bottom surface of the substantially planar flexible substrate.

[0316] Clause 82: The method of any of clauses 79 to 81, further comprising applying a protective coating to a perimeter of the substantially planar flexible substrate.

Claims

WHAT IS CLAIMED IS:

1. A catheter comprising:a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; anda flexible tip portion extending from the distal end of the catheter shaft, the flexible tip portion comprising:at least one flexible framework comprising a plurality of electrode-carrying arms, wherein each electrode-carrying arm extends from a distal end of the catheter shaft, wherein each of the plurality of electrode-carrying arms converges with at least one other of the plurality of electrode-carrying arms at a distal end of the at least one flexible framework; anda plurality of electrodes coupled to the electrode-carrying arms; wherein each of the plurality of electrode-carrying arms comprises a shape memory material to predispose the at least one flexible framework into a plane, wherein at least a portion of the plane of the at least one flexible framework is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration.

2. The catheter of claim 1, wherein the plane of the at least one flexible framework is disposed at the angle in the range of 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration and the plurality of electrodes coupled to the electrode-carrying arms form a flexible, planar array of electrodes.

3. A catheter comprising:a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; anda flexible tip portion comprising:at least one flexible framework comprising a plurality of electrode-carrying arms, wherein each of the plurality of electrode-carrying arms converges with at least one other of the plurality of electrode-carrying arms at a distal end of the at least one flexible framework, wherein each of the plurality of electrode-carrying arms comprises a shape memory material to predispose the at least one flexible framework into a plane, wherein the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration;a plurality of electrodes coupled to the electrode-carrying arms; and an intermediate portion between the distal end of the catheter shaft and the flexible tip portion, the intermediate portion comprising a shape memory material predisposed into at least a partial loop disposed in a plane intersecting the catheter shaft longitudinal axis, and wherein the at least one flexible framework is disposed at a distal end of the intermediate portion.

4. The catheter of claim 3, wherein the at least partial loop of the intermediate portion is disposed in a plane orthogonal to the catheter shaft longitudinal axis, wherein either a) each of the plurality of electrode-carrying arms extends from a distal end of the catheter shaft and through the intermediate portion, such that each arm is predisposed into the at least partial loop, or b) each of the plurality of electrode-carrying arms extends from a distal end of the intermediate portion.

5. The catheter of any preceding claim, further comprising a second flexible framework having a plurality of electrode-carrying arms, wherein each of the plurality of electrode-carrying arms comprises a shape memory material to predispose the second flexible framework into a second plane, wherein at least a portion of the second plane of the second flexible framework is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration.

6. The catheter of claim 5, wherein each of the flexible frameworks are distributed around the catheter shaft longitudinal axis and are evenly spaced around one side of the distal end of the catheter shaft.

7. The catheter of any preceding claim, wherein the flexible framework comprises at least two electrode-carrying arms, optionally at least four electrode-carrying arms, further optionally a first inboard arm, a second inboard arm, a first outboard arm, and a second outboard arm, and further optionally, a first midboard arm.

8. The catheter of any of claims 2 to 7, wherein the plurality of electrodes coupled to the electrode-carrying arms forms a flexible, planar array of electrodes.

9. The catheter of any preceding claim, wherein the plurality of electrodes comprises a first array of electrodes patterned onto the plurality of electrode-carrying arms.

10. The catheter of claim 9, further comprising a second array of electrodes patterned onto the plurality of electrode-carrying arms, wherein the first array and second array of electrodes comprises a row of longitudinally-aligned electrodes aligned parallel to the electrode carrying arms, optionally, wherein the first array is arranged on a first side of the electrode-carrying arms and the second array is arranged on a second side of the electrode-carrying arms.

11. The catheter of any preceding claim, wherein the plurality of electrodes are coupled to the plurality of electrode-carrying arms via a plating process.

12. The catheter of any of claims 1 to 8, wherein the plurality of electrodes are ring electrodes.

13. The catheter of any preceding claim, further comprising a plurality of conductive traces disposed on the flexible tip portion, each of the plurality of conductive traces electrically coupled with a respective one of the plurality of electrodes.

14. The catheter of claim 13, further comprising a mounting portion connected to the plurality of electrode-carrying arms, wherein the mounting portion includes a plurality of contact pads electrically coupled with the plurality of electrodes via the plurality of conductive traces.

15. The catheter of any of claims 13 or 14, further comprising a nonconductive material disposed between each of the plurality of conductive traces and the flexible tip portion, optionally, further comprising a nonconductive material disposed over an outward facing surface of each of the plurality of conductive traces.

16. The catheter of any one of claims 13 to 15, wherein each of the plurality of conductive traces is aligned parallel to the axis of the respective electrode-carrying arm.

17. The catheter of any preceding claim, further comprising a plurality of tubular polymeric members, each tubular polymeric member comprising a first open end and an opposed second open end defining an open lumen therebetween, the tubular polymeric member comprising an inner member surface and an outer member surface, wherein at least one of the plurality of electrode-carrying arms is at least partially disposed within the lumen of said tubular polymeric member.

18. A method of manufacturing a catheter, the method comprising:forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis;disposing shape memory material into a plurality of electrode-carrying arms and arranging at least a portion of each of the electrode-carrying arms into a single common plane to form a flexible framework;disposing the electrode-carrying arms at the distal end of the catheter shaft to form a flexible tip portion of the catheter and setting the shape of the flexible tip portion such that the plane of the flexible framework is predisposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; andsecuring the electrode-carrying arms to the distal end of the catheter shaft.

19. The method of claim 18, further comprising coupling a plurality of electrodes on the plurality of electrode-carrying arms.

20. The method of claim 18 or 19, further comprising disposing a polymeric tube over the shape memory material electrode-carrying arms; wherein coupling the plurality of electrodes on the plurality of electrode-carrying arms comprises mounting the electrodes on the polymeric tube of each of the plurality of electrode-carrying arms.

21. The method of claim 20, wherein the method further comprises annealing the framework comprising the polymeric tube, optionally wherein annealing takes place at a temperature of 82 to 105°C.

22. The method of claim 18 or 19, further comprising disposing an annealed polymeric tube over the shape memory material electrode-carrying arms; wherein coupling the plurality of electrodes on the plurality of electrode-carrying arms comprises mounting the electrodes on the polymeric tube of each of the plurality of electrode-carrying arms, optionally wherein the annealing of the polymeric tube takes place at a temperature of 82 to 105°C.

23. The method of any of claims 18 to 22, wherein setting the shape of the flexible tip portion comprises:bending the shape memory material such that the plane of the flexible framework is at the angle in the range of 80 to 130 degrees to the longitudinal axis of the catheter shaft;fixing the shape of the flexible framework; andquenching the flexible framework.

24. The method of claim 23, wherein the fixing takes place at a temperature in a range of 490-540°C, optionally in a salt bath.

25. The method of claim 23 or 24, wherein the bending comprises a radius of curvature in a range of 3 to 5mm, preferably 3.81mm.

26. A method of manufacturing a catheter, the method comprising:forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis;disposing shape memory material into an intermediate portion at a distal end of the catheter shaft and setting the shape memory material into at least a partial loop disposed in a plane, wherein the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft;disposing a flexible framework comprising a plurality of electrode-carrying arms at the distal end of the intermediate portion, wherein each of the plurality of electrode-carrying arms converges with at least one other of the plurality of electrode-carrying arms at a distal end of the flexible framework, wherein the electrode-carrying arms of the flexible framework are arranged in-plane in a single common plane, such that the plane is disposed at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; and securing the intermediate portion to the distal end of the catheter shaft.

27. The method of claim 26, wherein the plurality of electrode-carrying arms comprises a shape memory material and each electrode-carrying arm extends from the distal end of the catheter shaft and extends through the intermediate portion, wherein the setting the shape memory material into the at least partial loop includes setting the shape memory wire of the plurality of electrode-carrying arms into at least a partial loop as part of the intermediate portion.

28. The method of claim 26, wherein the disposing the flexible framework comprising the plurality of electrode-carrying arms at the distal end of the intermediate portion comprises securing each electrode-carrying arm to the distal end of the intermediate portion.

29. The method of any of claims 26 to 28, further comprising coupling a plurality of electrodes on the plurality of electrode-carrying arms.

30. The method of claim 29, further comprising disposing a polymeric tube over the electrode-carrying arms; wherein coupling the plurality of electrodes on the plurality of electrode-carrying arms comprises mounting the electrodes on the polymeric tube of each of the plurality of electrode-carrying arms.

31. A catheter comprising:a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; anda flexible tip portion comprising:a flexible framework comprising a substantially planar flexible substrate; a plurality of electrodes mounted on the flexible substrate; and a plurality of flexible struts coupled between the distal end of the catheter shaft and the flexible substrate, wherein each of the plurality of flexible struts comprise shape memory material configured to position the substantially planar flexible substrate in a plane that is at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft in a deployed configuration.

32. The catheter of claim 31, wherein the plurality of flexible struts are coupled to a perimeter of the flexible substrate.

33. The catheter of claim 31 or 32, wherein the plurality of flexible struts are each axially compressible to allow for reaction to applied forces while maintaining the flexible substrate in the plane at the angle in the range of 80 to 130 degrees to the longitudinal axis of the shaft.

34. The catheter of claims 31 to 33, wherein the plurality of flexible struts each has a curved shape, optionally wherein the curved shape comprises a wave shape or a multicurve shape, optionally a S-shape.

35. The catheter of claims 31 to 34, wherein plurality of flexible struts are each coupled to the distal end of the catheter shaft at an expansion angle of about 30 to 60 degrees to the longitudinal axis of the catheter shaft, optionally at an expansion angle of about 45 degrees to the longitudinal axis of the catheter shaft.

36. The catheter of any of claims 31 to 35, wherein the plurality of electrodes comprises a first array of electrodes patterned onto the substantially planar flexible substrate, wherein the first array of electrodes are arranged in a grid configuration.

37. The catheter of claim 31, wherein the substantially planar flexible substrate comprises a top surface and a bottom surface, the bottom surface being parallel with the top surface;wherein the plurality of electrodes comprises a second array of electrodes patterned onto the bottom surface of the substantially planar flexible substrate, wherein the second array of electrodes are arranged in a grid configuration; andwherein the first array of electrodes is patterned onto the top surface of the substantially planar flexible substrate, optionally wherein the first array of electrodes is aligned with the second array of electrodes.

38. The catheter of any of claims 31 to 37, further comprising a plurality of conductive traces disposed on the substantially planar flexible substrate, each of the plurality of conductive traces electrically coupled with a respective one of the plurality of electrodes, optionally further comprising a non-conductive material disposed over an outward facing surface of the conductive traces.

39. A method of manufacturing a catheter, the method comprising:forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis;disposing a shape memory material into a plurality of struts and setting the shape memory material of each of the plurality of struts into a curved shape;coupling a flexible framework comprising a substantially planar flexible substrate to the distal ends of each of the plurality of struts, wherein the flexible substrate is disposed in a plane that is at an angle in range from 80 to 130 degrees to the longitudinal axis of the catheter shaft; andsecuring the plurality of struts to the distal end of the catheter shaft.

40. The method of claim 39, wherein the curved shape comprises a wave shape or a, multi-curve shape, optionally a S-shape.

41. The method of claim 39 or 40, wherein disposing the struts at the distal end of the catheter shaft comprises disposing the struts at an expansion angle of about 30 to 60degrees to the longitudinal axis of the catheter shaft, optionally at an expansion angle of about 45 degrees to the longitudinal axis of the catheter shaft.

42. The method of any of claims 39 to 41, wherein the substantially planar flexible substrate comprises a plurality of electrodes mounted or patterned on a top and / or bottom surface of the substrate.

43. The method of any of claims 39 to 42, further comprising disposing a polymeric tube over the shape memory material struts.

44. The method of claim 43, wherein the method further comprises annealing the struts comprising the polymeric tube, optionally wherein annealing takes place at a temperature of 82 to 105°C.

45. The method of any of claims 39 to 44, wherein setting the shape memory material of the plurality of struts comprises:bending the shape memory material into the curved shape;fixing the curved shape of the struts; andquenching the struts.

46. The method of claim 45, wherein the fixing takes place at a temperature in range of 490-540°C, optionally in a salt bath.

47. The method of any of claims 39 to 46, wherein the coupling the flexible framework comprising the substantially planar flexible substrate to the distal ends of each of the plurality of struts comprises coupling the flexible struts to a portion of a perimeter of the flexible substrate.

48. A catheter comprising:a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; andan expandable assembly, wherein the expandable assembly comprises:a balloon member having a top surface, a bottom surface, and an interior cavity, each of the top surface and the bottom surface having an outer facing layer and an inner facing layer;a top flexible framework disposed between the outer facing layer and the inner facing layer of the top surface of the balloon member;a bottom flexible framework disposed between the outer facing layer and the inner facing layer of the bottom surface of the balloon member;a first plurality of electrodes patterned onto the top flexible framework;a second plurality of electrodes patterned onto the bottom flexible framework, wherein the first plurality of electrodes are aligned with the second plurality of electrodes;a plurality of conductive traces disposed on each of the flexible frameworks, each of the plurality of conductive traces electrically coupled with a respective one of the first plurality of electrodes and the second plurality of electrodes; anda flexible structural element disposed within the interior cavity;wherein the expandable assembly comprises a first delivery configuration, a second deployed configuration, and an intermediate configuration between the first delivery configuration and the second deployed configuration,wherein, in the intermediate configuration, the balloon member is unconstrained from an introducer sheath and uninflated, and the balloon member has a substantially planar shape, and wherein the flexible structural element comprises a shape memory material to predispose the balloon member in a plane at an angle in a range from 80 to 130 degrees to the longitudinal axis of the shaft.

49. The catheter of claim 48, wherein the shape memory material flexible structural element is disposed between the top flexible framework and the bottom flexible framework.

50. The catheter of claim 48 or 49, wherein the balloon member has a substantially flat shape, concave shape, or convex shape in the second deployed configuration.

51. The catheter of any of claims 48 to 50, wherein the balloon member comprises a plurality of apertures on the outer facing layer of the top surface and the bottom surface of the balloon member configured to expose the respective first plurality of electrodes and the second plurality of electrodes, optionally wherein a diameter of the plurality of apertures is the same size or smaller than a diameter of the respective first and second plurality of electrodes.

52. The catheter of any of claims 48 to 51, wherein the flexible structural element is configured to inflate the balloon member in the second deployed configuration, or wherein the elongate catheter shaft comprises an inflation lumen coupled to the interior cavity of the balloon member, wherein the balloon member in the first delivery configuration is uninflated and in the second deployed configuration is inflated via a liquid or a gas delivered through the inflation lumen, optionally wherein the inflation lumen is an oval inflation lumen.

53. The catheter of any of claims 48 to 52, wherein each of the first plurality of electrodes and the second plurality of electrodes are arranged in horizontal rows relative to the longitudinal axis of the elongate catheter shaft, optionally wherein the horizontal rows are offset such that each electrode in each row is offset from a respective electrode in an adjacent row.

54. The catheter of any of claims 48 to 53, wherein each of the first plurality of electrodes and the second plurality of electrodes are arranged in vertical rows parallel to the longitudinal axis of the elongate catheter shaft, wherein the vertical rows are offset such that each electrode in each row is offset from a respective electrode in an adjacent row.

55. A catheter comprising:a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis; anda flexible tip portion comprising:a flexible framework comprising at least one substantially planar flexible substrate, wherein the at least one substantially planar flexible substrate is petal-shaped and comprises a top surface and a bottom surface, wherein the substantially planar flexible substrate has a free distal end and a proximal end that is coupled to the distal end of the catheter shaft;a plurality of electrodes coupled to the at least one substantially planar flexible substrate; anda distal hub located at the distal end of the catheter shaft;wherein the flexible petal-shaped substrate is adapted to transition between a first delivery configuration to a second deployed configuration wherein the free distal end of the flexible petal-shaped substrate is positioned radially outwardly from the proximal end and the substantially planar flexible substrate comprises shape memory material to predispose theflexible petal-shaped substate in a plane at an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft.

56. The catheter of claim 55, wherein each of the substantially planar flexible substrates bows outwardly into the second deployed configuration.

57. The catheter of claim 55 or 56, wherein the flexible framework comprises two or more substantially planar flexible substrates and the substantially planar flexible substrates are evenly distributed around the distal end of the catheter shaft.

58. The catheter of any one of claims 55 to 57, wherein the petal-shape of the or each substantially planar flexible substrate is selected from one of elliptical, truncate, obovate, ovate, lanceolate, or round.

59. The catheter of any one of claims 55 to 58, wherein the shape memory material comprises nitinol and an entire top surface of each of the substantially planar flexible substrates is configured to form an ablation electrode.

60. The catheter of claim 59, wherein the plurality of electrodes are mounted on at least the bottom surface of the or each of the substantially planar flexible substrates.

61. The catheter of any one of claims 55 to 58, wherein the plurality of electrodes are mounted on the bottom surface and the top surface of the or each of the substantially planar flexible substrates.

62. The catheter of any one of claims 60 or 61, further comprising a flexible circuit mounted on at least the bottom surface of the or each of the substantially planar flexible substrates, or when dependent on claim 61, on the top and bottom surface of the or each of the substantially planar flexible substrates.

63. The catheter of any one of claims 55 to 59, wherein the or each substantially planar flexible substrate further comprises at least one cut-out region.

64. The catheter of claim 63, further comprising a flexible circuit inside the cutout region of the or each of the substantially planar flexible substrates, the flexible circuit coupled to the plurality of electrodes for mapping.

65. The catheter of claim 64, wherein the or each of the substantially planar flexible substrates comprise two layers of nitinol and wherein the cut-out region is formed in both layers of the nitinol, further comprising a flexible circuit layer positioned between the two nitinol layers and within the cut-out region, the flexible circuit coupled to the plurality of electrodes.

66. The catheter of any one of claims 62, 64 or 65, wherein the flexible circuit comprises a plurality of conductive traces disposed on the flexible tip portion, each of the plurality of conductive traces electrically coupled with a respective one of the plurality of electrodes.

67. The catheter of claim 66, further comprising a mounting portion coupled to the substantially planar flexible substrates, wherein the mounting portion includes a plurality of contact pads electrically coupled with the plurality of conductive traces and configured to couple with the plurality of electrodes.

68. The catheter of any of claims 66 or 67, further comprising a nonconductive material disposed between each of the plurality of conductive traces and the substantially planar flexible substrates, optionally, further comprising a nonconductive material disposed over an outward facing surface of each of the plurality of conductive traces.

69. The catheter of any of claims 60 to 68, wherein each electrode of the plurality of electrodes is configured as a band on the bottom surface and / or the top surface of the substantially planar flexible substrate.

70. The catheter of any of claims 60 to 68, wherein each electrode of the plurality of electrodes is deposited on the bottom surface and / or the top surface of the substantially planar flexible substrate.

71. The catheter of claim 70, wherein the plurality of electrodes comprise a first electrode arrangement configured for ablation, and / or a second electrode arrangement configured for mapping, wherein the first arrangement is larger than the second arrangement.

72. The catheter of claim 71, wherein the first electrode arrangement is located near the distal end of each of the substantially planar flexible substrates and the secondelectrode arrangement is located near the proximal end of each of the substantially planar flexible substrates.

73. The catheter of any of claims 55 to 72, further comprising a protective coating around a perimeter of each of the substantially planar flexible substrates.

74. The catheter of claim 73, wherein the protective coating comprises a polymeric material.

75. The catheter of any of claims 55 to 74, further comprising a distal hub electrode located at the distal hub.

76. The catheter of any of claims 55 to 75, wherein the plurality of electrodes for mapping are electrically isolated and independently activated from the petal-shaped substrate for ablation.

77. The catheter of any of claims 55 to 76, further comprising a steering ring at or near the distal end of the catheter shaft.

78. The catheter of any of claims 55 to 77, further comprising an introducer sheath configured for advancement over the flexible tip portion to bring the substantially planar flexible substrates into a first delivery configuration and for retraction from the flexible tip portion to bring the substantially planar flexible substrates into a second deployed configuration.

79. A method of manufacturing a catheter, the method comprising:forming a catheter shaft comprising a proximal end and a distal end, and defining a catheter shaft longitudinal axis;forming a flexible framework comprising at least one substantially planar petalshaped flexible substrate comprising nitinol; andcoupling the flexible framework to the distal end of the catheter shaft such that a proximal end of the at least one substantially planar petal-shaped flexible substrate is coupled to the distal end of the catheter shaft and setting the nitinol of the flexible framework such that a plane of the at least one substantially planar petal-shaped flexible substrate defines an angle in a range from 80 to 130 degrees to the longitudinal axis of the catheter shaft.

80. The method of claim 79, further comprising coupling a plurality of electrodes onto a top and / or bottom surface of the substantially planar flexible substrate.

81. The method of any of claims 79 to 80, further comprising mounting at least one flexible circuit onto the top and / or bottom surface of the substantially planar flexible substrate.

82. The method of any of claims 79 to 81, further comprising applying a protective coating to a perimeter of the substantially planar flexible substrate.

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