Shape-changing electrophysiology catheter

Abstract

The present disclosure relates to catheters comprising a catheter shaft comprising a proximal end and a distal end, and a flexible tip portion comprising an expandable flexible framework comprising a plurality of electrode-carrying arms, wherein each of the plurality of electrode-carrying arm converges with at least one other of the plurality of electrode-carrying arm at a distal apex of the flexible tip portion and wherein each of the plurality of electrode-carrying arms comprises a shape-memory material, and a plurality of electrodes mounted on the electrode-carrying arms. An inflatable balloon is positioned within the expandable flexible framework and is selectively inflatable to adjust the expandable flexible framework from a first non-expanded configuration in which the plurality of electrode-carrying arms form a flexible, substantially planar array, to a second expanded configuration securing a position of the plurality of electrode-carrying arms in an expanded array.

Description

PATENTAtorney Docket No. 108606-024010PC-1527863 Client Ref. No. 15837WOO1SHAPE-CHANGING ELECTROPHYSIOLOGY CATHETERCROSS-REFERENCES TO RELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 63 / 733,033 filed December 12, 2024; the full disclosures of which are incorporated herein by reference in their entirety for all purposes.FIELD OF THE DISCLOSURE

[0002] The present application relates to systems and apparatuses for catheter-based cardiac electrophysiology mapping and therapy. In particular, the present disclosure relates to shape-changing electrophysiology catheters for mapping and therapy, including catheter assemblies with balloons.BACKGROUND

[0003] 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.

[0004] 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 spline elements in an attempt to analyze or map the electrical activity within a heart chamber and / or to contact the 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 node, and spreads from the right atrium to the left atrium. Atrial depolarization is represented by the P wave on theelectrocardiogram. The QRS complex reflects the rapid depolarization of the right and left ventricles. The T wave represents the repolarization (or recovery) of the ventricles.

[0005] 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 EP2995250B1, US10,857,349B and EP3679861A.

[0006] 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 navigation 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 tissue configurations and to provide sufficient contact with the tissue for therapy, it can be important to have multiple sensors coupled with flexible spline elements on structures such as distal basket configurations to map the tissue and / or to contact the tissue for therapy. The ability to vary the stiffness of the flexible spline elements can allow for more useful configurations of the baskets or other flexible structures (e.g., more contact with tissue for treatment, etc.). Expandable catheters comprising systems to allow the stiffness of the expandable structure to be modified are described in US11,813, 410B2 and EP3681427B1. For different size applications, differentcatheters can be used (as described in US2019 / 239767), which can result in multiple catheters being required for a single procedure.

[0007] Balloon catheters may be used advantageously to expand basket catheters from their collapsed or semi-collapsed form during insertion into the body into to its expanded form in a body cavity. Additionally, the balloon may include irrigation holes through which irrigation fluid is pumped to cool the electrodes in use. The balloon enables strategically placing the irrigation holes with respect to the electrodes to enhance cooling during use. These advantages, and others, of balloon catheters are set out in US 11,974, 803B. Larger balloon catheters are not designed to map with high-density signal acquisition capabilities and ablate from the same catheter.

[0008] Once at the intended site, electrodes mounted on or in the electrophysiology catheters are used to treat the cardiac tissue. Treatment may include radio frequency (RF) ablation, pulsed field (PF) ablation, cryoablation, lasers, chemicals, high-intensity focused ultrasound, etc. An ablation catheter imparts such ablative energy to cardiac tissue to create a lesion in the cardiac tissue. This lesion disrupts undesirable electrical pathways and thereby limits or prevents stray electrical signals that lead to arrhythmias. As is readily apparent, such treatment requires precise control of the catheter during manipulation to and at the treatment site, which can invariably be a function of a user’s skill level.

[0009] Because RF ablation can generate significant heat, which if not controlled can result in excessive tissue damages, such as steam pop, tissue charring, and the like, it can be desirable to monitor the temperature of ablation electrode assemblies. An increase in temperature can be beneficial for PFA applications, but it is desirable to manage the degree of temperature change. It can also be desirable to include a mechanism to irrigate the ablation electrode assemblies and / or targeted areas in a patient’s body with biocompatible fluids, such as saline solution. The use of irrigated ablation electrode assemblies can also prevent the formation of soft thrombus and / or blood coagulation, as well as enable deeper and / or greater volume lesions as compared to conventional, non-irrigated catheters at identical power settings.BRIEF SUMMARY OF THE DISCLOSURE

[0010] The present invention generally relates to expandable catheters for use in electrophysiology, and more specifically to shape-changing catheters for use in diagnosing and / or treating cardiac arrhythmias.

[0011] In 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 extending between the proximal end and the distal end. A flexible tip portion is at the distal end of the catheter shaft, the flexible tip portion comprising: an expandable 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 arm converges with at least one other of the plurality of electrode-carrying arm at a distal apex of the flexible tip portion and wherein each of the plurality of electrode-carrying arms comprises a shape-memory material. A plurality of electrodes are mounted on the electrode-carrying arm. An inflatable balloon is positioned within the expandable flexible framework formed from the plurality of electrode-carrying arms, the balloon selectively inflatable to adjust the expandable flexible framework from a first non-expanded configuration in which the plurality of electrode-carrying arms form a flexible, substantially planar array, to a second expanded configuration securing a position of the plurality of electrode-carrying arms in an expanded array.

[0012] In a second aspect of the invention there is provided a catheter comprising: a handle comprising a control mechanism and a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis extending between the proximal end and the distal end. A flexible tip portion is at the distal end of the catheter shaft, the flexible tip portion comprising: an expandable 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 arm converges with at least one other of the plurality of electrode-carrying arm at a distal apex of the flexible tip portion and wherein each of the plurality of electrode-carrying arms comprises a shapememory material, wherein the expandable flexible framework has a first non-expanded configuration and a second expanded configuration. A plurality of electrodes are mounted on the electrode-carrying arms, wherein in the first non-expanded configuration the plurality of electrode-carrying arms form a flexible, substantially planar array, and wherein the second expanded configuration secures a position of the plurality of electrode-carrying arms in an expanded array. The catheter further comprises an expansion control member having a distal end coupled to the distal apex, wherein the control mechanism is drivingly coupled with the distal apex via the expansion control member and operable to move the expansion control member distally relative to the catheter shaft to collapse the expandable flexible framework from the second expanded configuration to the first non-expanded configuration and movethe expansion control member proximally relative to the catheter shaft to radially outwardly expand the expandable flexible framework from the first non-expanded configuration to the second expanded configuration.

[0013] The catheter may be a high-density mapping catheter and / or a map-ablate catheter. The flexible tip portions of these catheters comprise an expandable flexible framework which acts as an underlying support framework that is adapted to conform to and remain in contact with tissue (e.g., a beating heart wall).

[0014] The expandable flexible framework has a first non-expanded configuration and a second expanded configuration when deployed. In the first non-expanded configuration, the shape of the flexible framework becomes substantially planar, with the electrode-carrying arms forming a flexible, substantially planar array. “Substantially planar” encompasses a first non-expanded configuration in which the plurality of electrode-carrying arms may lie in a single plane (e.g. with the plane passing through the centers of each of the plurality of electrode-carrying arms) or in which the plurality of electrode-carrying arms may be arranged (e.g. stacked) such that a single plane contacts a part of each of the plurality of electrodecarrying arms. A plane may pass through the centers of one or more of the electrode-carrying and touch the circumference of one or more other electrode-carrying. Slight variations in position of the electrode-carrying arms are intended to be encompassed by the term “substantially planar”. In the substantially planar array, the electrodes on the electrodecarrying arms may be configured to contact tissue on a “front side” and / or a “back side” of the substantially planar array. The substantially planar array can be used with a sweeping and / or push motion to conform to tissue. The non-expanded flexible framework is configured to facilitate relative movement among at least some of the plurality of electrodes relative to other of the plurality of electrodes. The shape memory material allows the flexible framework to be pressed onto the cardiac surfaces, such that it is possible to acquire high-density mapping signals for electrophysiology diagnostics, optionally with unipolar signals, bipolar signals, and omnipolar signals. The large area mapping achieved from the substantially planar flexible framework is advantageous, particularly when the shaft is parallel to the cardiac wall.

[0015] Omnipolar techniques are direction-independent sensing techniques during mapping and are described further in CN110494080B, titled “Orientation independent sensing, mapping, interface and analysis systems and methods”, the entire disclosure of which is incorporated herein by reference.

[0016] In the second expanded configuration, a position of the plurality of electrodecarrying arms is secured. The catheter design would therefore also allow “single shot”Pulmonary Vein Isolation (PVI) by expanding the catheter positioned within a vein so that the majority of electrodes may contact the vein at once and ablating.

[0017] The catheter is thus able to expand to a large volume shape and then collapse to a customized shape-memory position that allows for large surface-area diagnostic mapping.

[0018] The expandable flexible framework may have a third folded configuration in an undeployed state. The expandable flexible framework comprises a plurality of electrodecarrying arms, where the arms (or the understructure of the arms) comprise a shape-memory material. The shape-memory material may be Nitinol. The construction (including, for example, the length and / or diameter of the arms) and material of the arms can be adjusted or tailored to create, for example, desired resiliency, flexibility, foldability, conformability, and stiffness characteristics, including one or more characteristics that may vary from the proximal end of a single arm to the distal end of that arm, or between or among the plurality of arms comprising the expandable flexible framework. The foldability of materials such as Nitinol provide the additional advantage of facilitating insertion of the expandable flexible framework into a delivery catheter or introducer, whether during delivery of the catheter into the body or removal of the catheter from the body at the end of a procedure. A guide sheath can be used to introduce the catheter into the body. The catheter can be inserted and retracted through the sheath.Arms

[0019] The electrode-carrying arms may be cylindrical or tubular in shape. Alternatively, the electrode-carrying arms may have a planar shape, for example, they may be elongate bodies, rectangular in cross-section.

[0020] A proximal coupler may be mounted on or within the distal end of the catheter shaft. The proximal portion of each of the electrode-carrying arms may extend through the proximal coupler. Each of the electrode-carrying arms may exit from a distal end of the proximal coupler (e.g. partially extending through the coupler). Each of the electrodecarrying arms may enter into a proximal end of the proximal coupler and exit from a distal end of the proximal coupler (e.g. extending through the entirety of the coupler).Alternatively, the proximal ends of each of the electrode-carrying arms may enter into a distal end of the catheter shaft and terminate distal of the proximal coupler. The proximal coupler may comprise a proximal coupler stem. The proximal coupler may comprise a proximal coupler cap. The proximal coupler cap may receive the proximal coupler stem. The proximal coupler cap may be coupled to a distal end of the proximal coupler stem. The proximal coupler may be arranged around the outer diameter of the catheter shaft or be containedwithin the lumen of the catheter shaft. The proximal coupler stem may be located within the catheter shaft and the proximal coupler cap may be located within or outside the catheter shaft. The proximal coupler cap may receive the proximal coupler stem alone, or in addition, may also receive the distal end of the catheter shaft. The proximal coupler may perform a variety of functions, including joining the electrode-carrying arms to the catheter shaft; acting as a manifold for irrigant; providing a structural support for the electrode-carrying arms, tubing, or internal components; and holding the electrode-carrying arms aligned and / or oriented. The proximal coupler stem may be a rigid structural component, e.g. a bushing or other suitable tubing. Alternatively, the proximal coupler may be formed from an adhesive or polymer reflow material, or any suitable material that can function as a coupler.

[0021] The flexible tip portion may be configured to prevent longitudinal movement between the electrode-carrying arms and the distal end of the catheter shaft. The flexible tip portion may be fixed to the proximal coupler. Each of the electrode-carrying arms may be fixed to the proximal coupler. Fixing the arms to the coupler can prevent longitudinal movement between the electrode-carrying arms and the distal end of the catheter shaft. Alternatively, each of the electrode-carrying arms may be adhesively and / or thermally bonded together at the distal end of the catheter shaft, optionally a proximal end of each of the electrode-carrying arms may be adhesively and / or thermally bonded together.

[0022] At least a portion of each of the plurality of electrode-carrying arms may be covered with a nonconductive material. The nonconductive material may be configured to insulate each of the plurality of electrodes from other of the plurality of electrodes. The nonconductive material may coat at least a portion of each of the electrode-carrying arms. The nonconductive material may comprise nonconductive polymers, for example high- dielectric nonconductive polymers such as polyether-etherketone, PEEK, polyether block amides, heat-shrink coating (e.g., PET), polyimide or PEBA.

[0023] The plurality of electrode-carrying arms may be longitudinally-extending and laterally separated electrode-carrying arms. The electrode-carrying arms may extend parallel to the catheter shaft longitudinal axis.

[0024] In the first non-expanded (deployed) configuration the plurality of electrodecarrying arms is such that the shape of the flexible framework is substantially planar. These arms are laterally separated from each other by approximately 2 to 5 mm, 3 to 4 mm, or 3.3 mm. The overall width of the flexible framework in the first non-expanded configuration may be 12 to 20 mm, 12 to 15 mm, or 12 mm.

[0025] The expandable flexible framework may comprise any number of arms. The expandable flexible framework may comprise between four and 16 electrode-carrying arms, for example 6, 8, 10 or 12 electrode-carrying arms. The expandable flexible framework may comprise 8 electrode-carrying arms, where the arms comprise a first outboard arm, a second outboard arm, a first mid-board arm, a second mid-board arm and four inboard arms.

[0026] The 8 arms may make two “halves” of the expandable flexible framework structure. Each half may comprise one mid-board arm and two inboard arms. The first and second outboard arms may be shared between both halves. In the first non-expanded configuration, 5 electrode-carrying arms may contact the tissue for high-density mapping, In the second expanded configuration, the 8 electrode-carrying arms may expand to provide a high volume.

[0027] An inflatable balloon may be positioned within the expandable flexible framework. The inflatable balloon may be positioned between two “halves” of the expandable flexible framework structure. The balloon may be selectively inflated to occupy the space between the electrode-carrying arms.

[0028] Where the term “planar” or, similarly, “plane” or “coplanar” is used herein, it should be understood to refer to a topological plane. In other words, a “plane” may not be “flat” in a Cartesian coordinate system, but rather represents a generally two-dimensional distribution that is planar in a topological sense. Likewise, where the term “linear” is used herein, it should be understood to refer to a topological plane. In other words, a “linear” may not be “straight line” in a Cartesian coordinate system, but rather represents a onedimensional distribution that is linear in a topological sense.Electrodes

[0029] The plurality of electrodes on the electrode-carrying arms form an electrode array or “array”. 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 0.5 to 5 mm, 3 to 4 mm, 1 to 3 mm, or by 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm or 4 mm (center-to-center distance). The electrodes may be longitudinally separated from each other by an edge-to-edge distance of approximately 0.25 to 3mm, 0.75 to 2.5 mm, or 1 to 2 mm. Smaller longitudinal spacing of the electrodes may be facilitated by using spot electrodes or flexible electrodes (and / or smaller, microelectrodes).

[0030] The plurality of electrodes may comprise any number of electrodes. The plurality of electrodes may comprise between 4 and 72 individual electrodes, for example 28, 32, 36, or 48 electrodes. Each electrode-carrying arm may comprise 3 to 8 electrodes. The firstoutboard arm, second outboard arm, first mid-board arm and second mid-board arm may comprise four electrodes, the four inboard arms may comprise three electrodes.

[0031] At least some of the electrodes may be ring electrodes. The ring electrodes may be 1.0 mm to 3.0 mm in length, for example 1.0 mm long. The ring electrodes may be 0.3 to 1.5 mm diameter, optionally 0.8 mm diameter. As discussed further below, a number of these ring electrodes may be slightly longer. Each of the four inboard arms may carry three small ring electrodes, spaced along its length. Where an inflatable balloon is present, all the electrodes may be ring electrodes.

[0032] The electrodes may be arranged on the electrode-carrying arms and configured for contacting tissue on a front side and a back side of the substantially planar array when in the first non-expanded configuration. At least one of the electrode-carrying arms may be onesided, such that the electrodes may be mounted only on one surface (or side) of the electrodecarrying arms. Each electrode-carrying arm may comprise an outward-facing surface (facing the exterior of the expandable flexible framework) and an inward-facing surface (facing the interior of the expandable flexible framework). Electrodes may be mounted on the outwardfacing surface of one or more of the electrode-carrying arms. Specifically, the electrodes may be mounted on the outward-facing surface (facing the exterior of the expandable flexible framework) of one or more of the electrode-carrying arms. More specifically, the electrodes may be mounted on the outward-facing surface of the first mid-board arm, second mid-board arm and inboard arms. Where the expansion mechanism comprises an inflatable balloon, additional electrodes may be mounted on the inward-facing surface of each arm. The inwardfacing electrodes may pair with a respective outward-facing electrode on the same electrodecarrying arm.

[0033] The electrodes may be mounted on the outward-facing surface of the first mid-board arm, second mid-board arm and inboard arms. Ring electrodes may be mounted on the first and second outboard arms.

[0034] The electrodes can be independently activated and / or deactivated during use (i.e., “selectively energized”). Individual electrodes may be independently activated and / or deactivated such that in the second expanded configuration, some of the electrodes can be turned off. For example, it may be desirable to turn off any electrodes facing the interior of the expandable flexible framework or some of the ring electrodes in the electrode array.

[0035] 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 small areas (such as 1 cm2) within the atrial walls of the heart; (2) identify complex fractionated atrialelectrograms 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. Additionally, the catheters described herein may be useful for epicardial and / or endocardial use. For example, in the first non-expanded configuration, the catheter may be used in an epicardial procedure where the substantially planar array of electrode-carrying arms is positioned between the myocardial surface and the pericardium. Alternatively, in the first non-expanded configuration the substantially planar array of electrode-carrying arms may be used in an endocardial procedure to quickly sweep and / or analyze the inner surfaces of the myocardium and quickly create high-density maps of the heart tissue's electrical properties. One or more of the plurality of electrodes in the electrode array could be used to send pacing signals to, for example, cardiac tissue.

[0036] A separate electrical lead wire or conductive trace may be electrically coupled to each electrode in the plurality of electrodes. The lead wires extending through the catheter shaft to each of the electrodes may comprise 38 AWG wire. The lead wires or conductive traces may be routed along the shape-memory material flexible framework from each of the electrodes to the proximal end of the catheter shaft. The lead wires may comprise a nonconductive sheath or coating.

[0037] 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 rows may be aligned parallel to the catheter shaft longitudinal axis.

[0038] The plurality of electrode-carrying arms 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.

[0039] The electrodes may be all the same size.

[0040] Four electrodes of the plurality of electrodes may be placed and configured as localization and focal ablation electrodes. Each of these four localization and focal ablation electrodes may be placed among a different row of the plurality of rows of electrodes.

[0041] The plurality of electrode-carrying arms may comprise a first outboard arm, a second outboard arm, a first mid-board arm and a second mid-board arm, each having an electrode slightly longer (enlarged) than the other electrodes. For example, the longerelectrodes 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 microelectrode. Each longer electrode may be the most-distal electrode on the first outboard arm, second outboard arm, first mid-board arm and second mid-board arm. Each longer electrode may be on a shoulder of the first outboard arm, second outboard arm, first midboard arm and second mid-board arm. These slightly enlarged electrodes (e.g., electrodes which slightly longer than the other ring electrodes) can be used, for example, for more precise localization of the flexible framework in mapping and navigation systems. It is also possible to drive ablation current between these enlarged electrodes, if desired, for bipolar ablation. Alternatively, it is possible to drive ablation current in unipolar mode between one or a combination of these enlarged electrodes and, for example a patch electrode located on a patient (e.g., on the patient's back). Similarly, the electrodes can be configured for use to perform unipolar, bipolar or omnipolar measurements or ablation. Alternatively or concurrently, current could travel between one or more of the enlarged electrodes and any one or all of the other electrodes. Unipolar measurements may generally represent the electrical voltage perceived at each electrode. Bipolar measurements may generally represent the electrical potential between any pair of electrodes. Unipolar or bipolar ablation can create specific lines or patterns of lesions.

[0042] The enlarged electrodes can be used to contact a cardiac surface distally when the flexible framework is in the second expanded configuration. The longer electrodes can acquire signals as well as be used for large focal ablations.

[0043] The plurality of electrode-carrying arms may be thermally or adhesively bonded to one another at the distal apex of the flexible tip portion. A distal coupler may be included at the distal apex of the flexible tip portion where the plurality of electrode-carrying arms come together. This distal coupler may be constructed from metal or some other radiopaque material to provide fluoroscopy visualization and optionally to provide semi-independent planar movement between the outer and inner arms. The distal coupler may be configured to be electrically active. That is, the distal coupler may be a distal electrode.

[0044] For bipolar PFA ablation capabilities, the electrically active distal coupler (or electrode) could be utilized as a bipolar reference, for example, to reduce shadow lesions and reduce the dependency of the lesions on the catheter shape or angle.

[0045] The inflatable balloon may be shaped such that the distal coupler is in-plane or near to in-plane with the longer electrodes when the flexible framework is in the second expandedconfiguration. The inflatable balloon may be custom-shaped (e.g. not perfectly rounded). The balloon shape can ensure that multiple electrodes can contact a cardiac surface at once. In the second expanded configuration, the longer electrodes and the distal electrode can be used to ablate hard-to-reach regions (e.g. the posterior heart walls) with the catheter shaft either parallel or perpendicular to the tissue surface (without having to reach the location with the shaft parallel to the wall).

[0046] In the second expanded configuration, ablations may be affected from (1) combinations of electrode pairs on the arms (when the shaft is parallel to a cardiac surface), (2) the longer electrodes (focal ablations), (3) a combination of the longer electrodes and the distal electrode at the distal coupler (when the shaft is perpendicular to a cardiac surface), (4) radially arranged electrodes (for “single shot” pulmonary vein ablations). Multiple ablation angles could be achieved with this configuration (i.e. 50 to 70°), for example, when pressing the flexible framework against the cardiac surface.Inflatable balloon expansion

[0047] The inflatable balloon may be collapsed during delivery. To perform mapping or ablation, the expandable flexible framework may be deployed into a first or second configuration. To achieve the second expanded configuration, the balloon is selectively inflated to occupy the space between the electrode-carrying arms. The inflatable balloon may be custom-shaped (e.g. not perfectly rounded). The shape of balloon may be selectively changed to improve ablation. An inflated balloon can isolate the electrodes from the interior cavity for ablation therapy delivery and improved signal to noise ratios. An inflatable balloon is also beneficial for PFA applications to direct current flow through the cardiac tissue.

[0048] In the first non-expanded configuration, the inflatable balloon member may have a flat, concave, or convex shape. For example, the inflatable balloon may be substantially flat. In the second expanded configuration, the inflated balloon member may extend outward in a central portion of the balloon member to form a convex shape.

[0049] An inner shaft member may be slidably positioned within the catheter shaft, with a distal end of inner shaft member coupled to a proximal end of the inflatable balloon. When the inner shaft member is pulled proximally relative to the catheter shaft, the inflatable balloon is also pulled proximally relative to the catheter shaft, thereby retracting the balloon. This mechanical retraction mechanism can assist in retracting the inflatable balloon into the catheter shaft.

[0050] The inflatable balloon is positioned within the expandable flexible framework formed from the plurality of electrode-carrying arms. A proximal end of the balloon may befixed to a distal end of the catheter shaft. A distal end of the balloon may be fixed to the distal apex of the flexible tip portion or to the distal coupler at the distal apex.

[0051] Mechanisms to inflate the balloon can include fluid inflation and mechanical inflation mechanisms. For example, an irrigation fluid may be used to inflate the inflatable balloon.

[0052] 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.

[0053] The fluid delivery lumen may be adapted to deliver the irrigant through the at least one irrigation hole on or adjacent to the array of electrodes. The fluid delivery lumen may be adapted to deliver the irrigant through the at least one irrigation hole to the inflatable balloon. The irrigation fluid may be used to inflate the inflatable balloon. The fluid may be saline or gas, or another suitable fluid. The fluid may include a contrast agent.

[0054] Multiple irrigation holes or ports could be present at various positions along the electrode-carrying arms and / or catheter shaft. At least one irrigation hole (or port) may be present at the distal end of the catheter shaft. At least one irrigation hole (or port) may be present at the distal end of the proximal coupler, for example at the distal end of the proximal coupler cap. A distal irrigation port set comprising multiple ports could be included at or near the distal apex of the flexible tip. For distal irrigation, the distal irrigation ports may be configured to provide angled flow to irrigate from the distal end of the catheter to the proximal end.

[0055] Alternative irrigation mechanisms may comprise an offset on the proximal coupler or proximal coupler cap from the outer circumference of the electrode-carrying arms. The space created between the proximal coupler or proximal coupler cap and the arms may allow bulk irrigation.

[0056] Alternative mechanisms can be envisaged for fluid balloon inflation. In one example, a channel may be defined between the catheter shaft and an inner shaft element. The channel may be in fluid communication with an interior of the inflatable balloon. A stopcock valve (e.g., a three-way stopcock valve) may enable inflating and deflating the balloon as desired, by controlling fluid flow to the interior of the inflatable balloon.

[0057] Mechanical inflation mechanisms can involve the use of a handle comprising a control mechanism. The flexible, expandable framework may comprise an expansion control member drivingly coupled with the control mechanism and operable to collapse theexpandable flexible framework from the second expanded configuration to the first nonexpanded configuration and to radially outwardly expand the expandable flexible framework from the first non-expanded configuration to the second expanded configuration. A distal end of the inflatable balloon may be coupled to the distal apex (or distal coupler).

[0058] The expansion control member can have an expansion control member distal end that can be coupled with a portion of the flexible framework (e.g., the distal apex) and an expansion control member proximal end that can be coupled with a control mechanism (e.g., a portion of the handle).

[0059] The expansion control member may comprise an inner shaft slidably positioned within the catheter shaft and through the interior of the balloon. A distal end of the inner shaft member may be coupled to the distal end of the inflatable balloon or to the distal apex (or distal coupler). The control mechanism is operable to move the inner shaft distally relative to the catheter shaft to collapse the expandable flexible framework from the second expanded configuration to the first non-expanded configuration and move the inner shaft proximally relative to the catheter shaft to radially outwardly expand the expandable flexible framework from the first non-expanded configuration to the second expanded configuration. The inner shaft expansion control member can include a lumen suitable for irrigation fluids. The inner shaft expansion control member can also include one or more irrigation ports.

[0060] The inner shaft expansion control member can pass through a central opening of the proximal coupler, for example through the proximal coupler stem, allowing the inner shaft expansion control member to be moved independently of the proximal coupler.

[0061] The expansion control member may alternatively or additionally comprise a pull wire located along at least two of the electrode-carrying arms. A pull wire may be located along each of the electrode-carrying arms and the pull wire has a distal end coupled to the distal apex. Alternatively, at least two pull wires may be located along the inner surface of the inflatable balloon and each pull wire has a distal end coupled to a distal end of the inflatable balloon. The distal end of the inflatable balloon may be fixed to the distal apex of the flexible tip portion or to the distal coupler at the distal apex. Each pull wire may have a proximal end coupled to the control mechanism. The control mechanism may be drivingly coupled with the distal apex via the pull wires to expand and collapse the expandable flexible framework.

[0062] The expansion control member may comprise one or more of a rigid or semi-rigid polymer, or a flexible metal, optionally stainless steel. The expansion control member may be a metal cable, cord or similar element).

[0063] The position of the inner shaft member and / or pull wires relative to the catheter shaft may be held in place using a suitable locking mechanism (e.g., a Tuohy Borst compression valve). The handle may include a selective movement limiter operable to limit movement of the expansion control member relative to the catheter shaft. The selective movement limiter may comprise a clamping mechanism (e.g. a clamp) engageable with the expansion control member. The clamp may comprise a first portion and a second portion, where the first portion is in a fixed position and the second portion is movable relative to the first portion to allow engagement with the expansion control member. Alternatively, the clamp may comprise a first portion and a second portion, where the first portion and the second portion are movable to allow engagement with the expansion control member.

[0064] The expansion control member may be configured to move freely when the selective movement limiter is not coupled with the expansion control member. The selective movement limiter may be configured as a clamp where the clamp engages the expansion control member and limits the longitudinal movement of the expansion control member.

[0065] The inflatable balloon may comprise a plurality of channels. Each channel may be configured to receive one of the plurality of electrode-carrying arms. In particular, each channel may be shaped to receive one of the plurality of electrode-carrying arms and secure the position of the arm. The channels may ensure known or constant arm-to-arm spacing when the flexible framework is in the second expanded configuration. The channels may feed into an omnipolar technology algorithm for continued omnipolar mapping while inflated and in the second expanded configuration. This would allow large-volume geometry mapping as well as allow ablations from the electrodes. In addition, this would allow for focal ablations from the enlarged electrodes with increased contact force or stability.

[0066] The inflatable balloon thickness may be 0.025 mm + / - 0.005 mm at an area surrounding the greatest outer diameter of the balloon. The inflatable balloon may comprise a variety of materials including thermoplastic polyurethanes (TPUs, such as Pellethane®), thermoplastic elastomers (TPEs), polyamides (including nylons or Pebax®), ethylene vinyl acetates (EVAs), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), silicon, silicone, and / or composite material combinations thereof. The material may be medical grade.

[0067] The inflatable balloon may drive more energy into ablated tissue, and stabilizes the flexible framework to prevent lateral movement of the electrode-carrying arms. The balloon can also function as an insulator, and generally reduces energy losses. This occurs because in the second expanded configuration the balloon causes the electrodes to primarily transferenergy outward, away from the balloon, resulting in the energy predominantly being transferred to target tissue instead of into the blood pool. The balloon may further act to reduce interference between electrodes when in the first non-expanded configuration, by positioning between the electrode-carrying arms.Alternative expansion mechanism

[0068] The deployment / undeployment of the expandable flexible framework can be controlled by the use of shape-memory materials that are self-erecting (e.g., Nitinol) or by pull wires or other similar mechanisms.

[0069] Mechanical expansion can be achieved via an expansion control member, according to the second aspect of the invention. The shape of the expandable flexible framework can vary depending on the configuration achieved using the expansion control member. The expansion control member can be moved distally relative to the catheter shaft to collapse the expandable flexible framework from the second expanded configuration to the first nonexpanded configuration. The expansion control member can be moved proximally relative to the catheter shaft to radially outwardly expand the expandable flexible framework from the first non-expanded configuration to the second expanded configuration. The expansion control member can move longitudinally, which can cause the expandable flexible framework to change shape. The expansion control member can be used to support a particular shape / configuration of the expandable flexible framework.

[0070] The expansion control member can have an expansion control member distal end that can be coupled with a portion of the flexible framework (e.g., the distal apex) and an expansion control member proximal end that can be coupled with a control mechanism (e.g., a portion of the handle). The expansion control member can include a lumen suitable for irrigation fluids. The expansion control member can also include one or more irrigation ports.

[0071] The expansion control member can pass through a central opening of the proximal coupler, for example the proximal coupler stem, allowing the expansion control member to be moved independently of the proximal coupler.

[0072] The expansion control member may comprise an inner shaft slidably positioned within the catheter shaft. A distal end of the inner shaft member may be coupled to the distal apex (or distal coupler). The inner shaft expansion control member can include a lumen suitable for irrigation fluids. The inner shaft expansion control member can also include one or more irrigation ports.

[0073] The inner shaft may be a rigid or semi-rigid material, including, but not limited to a polymer or metal (such as stainless steel).

[0074] The expansion control member may alternatively or additionally comprise a pull wire located along at least two of the electrode-carrying arms. A pull wire may be located along each of the electrode-carrying arms and the pull wire has a distal end coupled to the distal apex. The pull wire may have a proximal end coupled to the control mechanism. The control mechanism may be drivingly coupled with the distal apex via the pull wires to expand and collapse the expandable flexible framework. The pull wire may comprise a metal cable, cord or similar element. The pull wire may comprise stainless steel.

[0075] The position of the inner shaft member and / or pull wires relative to the catheter shaft may be held in place using a suitable locking mechanism (e.g., a Tuohy Borst compression valve).

[0076] The handle may include a selective movement limiter operable to limit movement of the expansion control member relative to the catheter shaft. The selective movement limiter may comprise a clamping mechanism (e.g. a clamp) engageable with the expansion control member. The clamp may comprise a first portion and a second portion, where the first portion is in a fixed position and the second portion is movable relative to the first portion to allow engagement with the expansion control member. Alternatively, the clamp may comprise a first portion and a second portion, where the first portion and the second portion are movable to allow engagement with the expansion control member.

[0077] The expansion control member may be further configured to adjust a stiffness of the expandable flexible framework, from a first stiffness to a second stiffness, and maintain the first stiffness or the second stiffness when the selective movement limiter couples with the expansion control member and limits a longitudinal movement of the expansion control member. The expansion control member may be configured to move freely when the selective movement limiter is not coupled with the expansion control member. The selective movement limiter may be configured as a clamp where the clamp engages the expansion control member and limits the longitudinal movement of the expansion control member.

[0078] The second aspect may additionally comprise an inflatable balloon positioned on the interior of the expandable flexible framework.Other features

[0079] There may be a number of additional electrodes located on the catheter shaft. There may be at least one electrode mounted on or within the distal end of the catheter shaft, for example adjacent to the flexible tip portion. The proximal coupler may be electrically active and / or there may be at least one electrode mounted on the proximal coupler. For example, theproximal coupler cap may be configured to be electrically active (e.g. metallic), and / or there may be at least one electrode mounted on the proximal coupler cap. There may additionally or alternatively be at least one electrode mounted on the proximal coupler stem.

[0080] In particular, there may be an electrode mounted on the most distal part of the catheter shaft (e.g. at the proximal coupler), 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 (or 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.

[0081] For bipolar PFA ablation capabilities, the additional electrode at the proximal coupler or proximal coupler cap could be utilized as a bipolar reference, for example, to reduce shadow lesions and reduce the dependency of the lesions on the catheter shape or angle. This additional electrode can assist in the creation of larger or deeper lesions.

[0082] In one example, the catheter may comprise 28 electrodes on the electrode-carrying arms (4 of which are enlarged electrodes), 1 distal electrode at the distal apex, 1 proximal electrode at the proximal coupler cap, and 2 catheter shaft electrodes (a distal shaft electrode and a proximal shaft electrode). The catheter may comprise a total of 32 electrodes.

[0083] The catheter may also comprise at least one location sensor. The at least one location sensor may be mounted in or on at least one of the following: the catheter shaft; or the distal apex of the flexible tip portion. The at least one location sensor may alternatively be located just proximal to the proximal coupler. These sensors may alternatively be mounted at other locations e.g., along the electrode carrying arms of the flexible framework and / or at the distal joint of the flexible tip portion, or at similar locations in catheters described herein. The at least one location sensor may be a magnetic field sensor. The at least one location sensor may be a pair of offset magnetic field sensors, optionally positioned in the catheter shaft. The magnetic field sensor(s) may be configured for use with an electromagnetic localization and navigation system. A variety of sensors may be incorporated in the catheters described herein. For example, a temperature sensor may be included in the catheter.

[0084] The catheter may be 6 to 12 Fr outer diameter, for example 7 F or 7.5 F. Other size catheters may be suitable, for example, sized to accommodate the expandable flexible framework.

[0085] A handle may be provided to act as a location for the clinician to hold the catheter. The handle may further provide means for steering or the guiding the shaft within a body. For example, the handle may include means to change the length of a guidewire extendingthrough catheter to distal end of the catheter shaft or means to steer the catheter shaft. Alternatively, the catheter may be robotically driven or controlled. Accordingly, rather than a clinician manipulating a handle to advance / retract and / or steer or guide the catheter (and shaft thereof in particular), a robot is used to manipulate the catheter.

[0086] The catheter shaft may be made from conventional materials such as polyurethane. The shaft may be introduced into a blood vessel or other structure within body through a conventional guide sheath or introducer. The shaft may then be advanced / retracted and / or steered or guided through body to a desired location such as the site of tissue, including through the use of guidewires or other means known in the art.

[0087] The catheter may be an electrophysiology catheter.Systems

[0088] A localization and navigation system may be provided for visualization, mapping and navigation of internal body structures. The localization and navigation system may include conventional apparatus known generally in the art (e.g., an EnSite™ X system, commercially available from Abbott Laboratories). It should be understood, however, that this system is an example only, and is not limiting in nature. Other technologies for locating / navigating a catheter in space (and for visualization) are known, including for example, the CARTO navigation and location system of Biosense Webster, Inc., the Rhythmia® system of Boston Scientific Scimed, Inc., the KODEX® system of Koninklijke Philips N.V., the AURORA® system of Northern Digital Inc., commonly available fluoroscopy systems, or a magnetic location system such as the gMPS system from Mediguide Ltd. In this regard, some of the localization, navigation and / or visualization system would involve a sensor be provided for producing signals indicative of catheter location information, and may include, for example one or more electrodes in the case of an impedance-based localization system, or alternatively, one or more magnetic sensors (e.g. coils (i.e., wire windings), or solid-state sensors) configured to detect one or more characteristics of a magnetic field, for example in the case of a magnetic-field based localization system. As yet another example, the system may utilize a combination electric field-based and magnetic field-based system as generally shown with reference to U.S. Pat. No. 7,536,218 entitled “Hybrid Magnetic-Based and Impedance Based Position Sensing,” the disclosure of which is incorporated herein by reference in its entirety.

[0089] The shape-changing catheter can be used in conjunction with any suitable localization and navigation system. For example, the catheter can be configured to perform ablation procedures, cardiac mapping, electrophysiological (EP) studies and other diagnosticand / or therapeutic procedures. For example, the catheter may be used for irreversible electroporation to destroy tissue. Electroporation is a non-thermal ablation technique that involves applying strong electric fields that induce pore formation in the cellular membrane. The electric field may be induced by applying a relatively short duration pulse which may last, for instance, from a nanosecond to several milliseconds. Such a pulse may be repeated to form a pulse train. When such an electric field is applied to tissue in an in vivo setting, the cells in the tissue are subjected to trans-membrane potential, which opens the pores on the cell wall. Electroporation may be reversible (i.e., the temporally-opened pores will reseal) or irreversible (IRE, i.e., the pores will remain open). For example, in the field of gene therapy, reversible electroporation (i.e., temporarily open pores) is used to transfect high molecular weight therapeutic vectors into the cells. In other therapeutic applications, a suitably configured pulse train alone may be used to cause cell destruction, for instance by causing irreversible electroporation.

[0090] Typically, for classical plasma membrane electroporation, electric energy may be delivered as a pulsed electric field (i.e., pulsed field ablation (PF A)) in the form of short- duration pulses (e.g. having a 10 nanosecond (ns) to 100 millisecond (ms) duration) between closely spaced electrodes capable of delivering an electric field strength of about 0.05 to 100.0 kilovolts / centimeter (kV / cm). For electroporation therapy, a generator may be configured to produce an electric energy that is delivered via the catheter as a pulsed electric field in the form of short-duration square wave pulses (e.g., a nanosecond to several milliseconds duration, or any duration suitable for electroporation) between closely spaced electrodes capable of delivering an electric field strength (i.e., at the tissue site) of about 0.05 to 100.0 kV / cm.

[0091] An electroporation generator may be configured to output energy in pulses at selectable energy levels, such as 50 joules (J), 100 J, 200 J, and the like. Other generators may have more, or fewer energy settings and the values of the available setting may be the same or different (settings may include, e.g., waveform parameters, voltage, current, number of applications, etc.). For successful electroporation, some generators utilize the 200 J output level. For example, an electroporation generator may output a pulse having a peak magnitude from about 10 Volts (V) to about 20,000 V. Other generators may output any other suitable positive or negative voltage. For example, pulses may have a voltage from 2,400 V to 4,000 V.

[0092] For example, the catheter may be configured as a bipolar electrode assembly for use in bipolar-based electroporation therapy. Specifically, the electrodes can be individuallyelectrically coupled to an electroporation generator (e.g., via suitable electrical wire or other suitable electrical conductors extending through the catheter shaft) and can be configured to be selectively energized by the electroporation generator with opposite polarities to generate a potential and corresponding electric field therebetween, for pulsed field or electroporation therapy. That is, one of electrodes can be configured to function as a cathode, and another of the electrodes can be configured to function as an anode. Any suitable combination of the electrodes of the catheter can be used as anodes and cathodes. The electric fields may be applied between adjacent electrodes (in a bipolar approach), between an electrode and a catheter shaft electrode (such as the proximal coupler electrode), between an electrode and a distal coupler electrode, or between a one or more electrodes and a return patch (in a monopolar approach).

[0093] The catheter can be used to selectively alter the patient’s heart tissue to reduce or eliminate the pathological electrical condition to reduce or eliminate occurrence of the cardiac arrythmia. The catheter can be configured for use in performing any suitable treatment, such as, but not limited to, radio frequency (RF) ablation, pulsed field ablation (PF A), cryoablation, laser ablation, chemical ablation, high-intensity focused ultrasound ablation, microwave ablation, and / or other ablation treatments.

[0094] According to a further aspect of the disclosure, there is provided a kit comprising the catheter and a delivery catheter. The catheter may be configured to receive an ablative energy (e.g., radio frequency and / or pulsed field) at the at least one ablation electrodes (e.g., second arm electrodes) and generate an electric field at the ablation electrodes. The electric field may have an electric field strength sufficient to ablate a target tissue via irreversible electroporation. The second arm ablation electrodes can be configured to be activated simultaneously to generate an electric field between the electrodes and a return patch. Using the catheter, sufficient lesions may be generated at an applied voltage of 50 to 10,000V, for example 100V, 1,300V, 2,000 V or 2,500 V, even for a 25mm diameter pulmonary vein. A voltage gradient of 400 to 600V / cm can be applied to cause cardiac cell death. Different electric fields may be suitable for different anatomical locations. Ablation energy (PF and / or RF energy) delivery may be from the at least one second arm electrode. Alternatively or in addition, ablation energy may be delivered from the first arm electrodes. The first and second arm electrodes may also be configured for mapping purposes.

[0095] Pulsed field energy may be delivered using any suitable waveform. A waveform may be delivered using an electroporation generator. An electroporation generator may be configured to output energy in pulses at selectable energy levels, such as 50 joules (J), 100 J,200 J, and the like. Other generators may have more, or fewer energy settings and the values of the available setting may be the same or different (settings may include, e.g., waveform parameters, voltage, current, number of applications, etc.). For successful electroporation (or PF A), some generators utilize the 200 J output level. For example, an electroporation generator may output a pulse having a peak magnitude from about 10 Volts (V) to about 20,000 V (or higher). Other generators may output any other suitable positive or negative voltage.

[0096] A waveform may include a positive pulse followed by a negative pulse. Further, there may be an intrapulse delay (which may also be referred to as an interphase delay) between the positive and negative pulses. The waveform may include a series of consecutive pairs of positive and negative pulses. That is, the waveform may include i) a first positive pulse followed by (i.e., after an intrapulse delay) a first negative pulse and ii) a second positive pulse followed by a second negative pulse. The time period between the beginning of the first positive pulse and the beginning of the second positive pulse (i.e., the time it takes for the pairs of positive and negative pulses to repeat) may be referred to as the pulse period. The intrapulse delay and / or the pulse period may be on the order of nanoseconds, microseconds, or milliseconds, and the intrapulse delay may be relatively short compared to the pulse period. However, any suitable time periods may be used.

[0097] Each pulse may have a pulse width and a pulse amplitude (which may also be referred to as a peak magnitude). For example, the positive pulse may have a first pulse width and a first pulse amplitude. Similarly, the negative pulse may have a second pulse width and a second pulse amplitude. When first pulse amplitude and second pulse amplitude are both non-zero, the waveform is biphasic. For a monophasic waveform, one of first pulse amplitude and second pulse amplitude is zero. For example, if the first pulse amplitude is zero, the waveform is monophasic with single negative pulse. If the second pulse amplitude is zero, the waveform is monophasic with single positive pulse. Pulse widths may be, for example, in a range from 0 nanoseconds to 5 microseconds, e.g., 3 microseconds. Pulse amplitudes may be, for example, in a range from 10 Volts to about 20,000 Volts, e.g., on the order of 1800 Volts. These values are examples, and any suitable pulse width and amplitude may be used.

[0098] The waveform may be symmetric (i.e., with the first pulse width and first pulse amplitude substantially equal to the second pulse width and second pulse amplitude) or asymmetric (i.e., with at least one of the first pulse width and first pulse amplitude different from the second pulse width and second pulse amplitude). 1

[0099] As used herein, “proximal” refers to a direction toward the end of the catheter near the clinician and “distal” refers to a direction away from the clinician and (generally) inside the body of a patient.

[0100] 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

[0101] The invention is further illustrated with reference to the following figures in which:

[0102] Figure 1 illustrates an example medical device localization and navigation system that can be employed in conjunction with the shape-changing catheter, in accordance with embodiments of the present disclosure.

[0103] Figure 2A shows an elevational, in-plane view of a first non-expanded configuration according to a first aspect of the invention (without the inflatable balloon shown).

[0104] Figure 2B shows an isometric view of the first non-expanded configuration of figure 2A.

[0105] Figure 2C shows a plan view of the first non-expanded configuration (perpendicular to the plane) of figure 2A.

[0106] Figure 2D shows an isometric view of the first non-expanded configuration of figure 2A with the inflatable balloon shown.

[0107] Figure 3 A shows a plan view of a second expanded configuration according to a first aspect of the invention (without the inflatable balloon shown).

[0108] Figure 3B shows an isometric view of the second expanded configuration of figure 3A.

[0109] Figure 3C shows a perspective view of the second expanded configuration of figure 3A.

[0110] Figure 4A shows an elevational, in-plane view of a first non-expanded configuration comprising electrodes configured for contacting tissue on a front side and a back side of the substantially planar array (without the inflatable balloon shown).

[0111] Figure 4B shows an isometric view of a first non-expanded configuration of figure 4A.

[0112] Figure 5 A shows a plan view of a second expanded configuration with the inflated balloon indicated, according to a first aspect of the invention.

[0113] Figure 5B shows a perspective view of a second expanded configuration of figure 5A.

[0114] Figure 5C shows a top-down view of the second expanded configuration of figure 5A with inflated balloon (viewed from the distal end of the catheter along the longitudinal axis).

[0115] Figures 6A and 6B show an inflatable balloon in a first non-expanded configuration comprising channels. Figures 6C and 6D show an inflated balloon comprising channels in a second expanded configuration, where figures 6B and 6D are top-down views of the balloon comprising channels.

[0116] Figures 7A and 7B show isometric views of a second expanded configuration comprising a mechanical expansion mechanism according to a second aspect of the invention.

[0117] Figures 8 A and 8B shows a perspective view of the distal end of the catheter shaft, with irrigation holes at the distal end of the proximal coupler.

[0118] Figure 9 shows a perspective view of an alternative irrigation system.

[0119] Figure 10 is a cross-section through the flexible tip portion, including an inflatable balloon, showing an alternative irrigation system.

[0120] Figure 11 is a sectional view of the distal end of the catheter shaft.

[0121] Figure 12 depicts the catheter against tissue in the first non-expanded configuration.

[0122] Figure 13 A depicts the catheter of the first aspect against tissue for focal ablation in the second expanded configuration (without the inflatable balloon shown).

[0123] Figure 13B depicts the catheter of the first aspect against tissue in a vein for PVI ablations in the second expanded configuration (without the inflatable balloon shown).DETAILED DESCRIPTION OF THE DISCLOSURE

[0124] Electrophysiology catheters are traditionally ablation catheters or mapping catheters. Ablation therapies, such as for atrial fibrillation, have extended durations as the clinician must introduce an electrophysiology mapping catheter into the patient's left atrium, confirm the diagnosis, and determine an ablation therapy strategy before removing the electrophysiology mapping catheter. An ablation catheter is then introduced to complete the ablation therapy, followed by reintroduction of the electrophysiology mapping catheter to confirm the efficacy of the therapy. In view of the foregoing, a catheter capable of both high- density electrophysiology mapping and ablation therapy would be desirable to limit the duration of the operation and improve patient safety and / or efficacy of diagnosis and therapy.It is also desirable for the all in one catheter to provide large surface-area diagnostic mapping with high-density signal acquisition capabilities, as well as large surface area ablations. The present disclosure seeks to provide a solution.

[0125] The present invention will now be further elaborated by reference to the figures which are non-limiting.

[0126] A localization and navigation system may be provided for visualization, mapping and navigation of internal body structures. As shown in Figure 1, the electrodes 200, 204 and distal tip electrode 202 of the shape-changing catheter 100 are configured to be conformable to a tissue (e.g., cardiac tissue) to interface the electrodes 200, 204 and distal tip electrode 202 with the tissue. Each electrode 200, 202, 204 is individually wired such that it can be selectively paired or combined with each other or any other additional electrode (e.g. 360, 370) on the catheter shaft or a patch electrode 18 located on a patient 17 to act as a bipolar or a multi-polar electrode. The flexible tip portion 10 and expandable flexible framework provides suitable flexibility to accommodate flexure of the electrodes 200, 204 in response to suitable interface forces between the flexible framework and the tissue.

[0127] The configuration of the flexible tip portion 10 and electrodes 200, 204 discussed herein facilitates insertion of the flexible tip portion 10 using a handle 110 of the catheter, deployment of the flexible tip portion 10 and electrodes 200, 204 within the heart 16, and withdrawal of the flexible tip portion 10 from the patient 17. For example, upon entering a target chamber of the heart 16, once deployed into the first non-expanded configuration, the flexible substantially planar array of electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 causes the electrodes 200, 204 to interface with the tissue as the flexible framework is swept across the tissue surface. When the expandable flexible framework is expanded (e.g., inflated), a different configuration of electrodes 200, 204 and distal tip electrode 202 can be used to contact tissue. The electrodes 200, 204 and distal tip electrode 202 can be used to interface with the tissue as the flexible framework is expanded, collapsed (e.g., deflated), advanced, or retracted to receive signals. The signals can be transmitted via the connector 56 to a system 108 for analysing the signal e.g., to determine localization.

[0128] Figure 1 also illustrates a diagrammatic view of a medical device localization system 108 that can be used in conjunction with the shape-changing catheter 100. The system 108 includes a main electronic control unit 112 (e.g., a processor) having various input / output mechanisms 114, a display 116, an electrocardiogram (ECG) monitor 120, a localization system, such as a localization and navigation system 122, and the shape-changing catheter 100. The shape-changing catheter 100 includes a plurality of electrodes 200, 204 and aflexible framework 182, 184, 186, 188, 192, 194, 196, 198, and optionally additional electrodes 202, 360, 370 and one or more location sensors 106, 107 (which may be magnetic field sensors).

[0129] 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.

[0130] The ECG monitor 120 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.

[0131] 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 106, 107 and / or the electrodes 200, 202, 204 and output a respective location reading. A plurality of return electrodes are diagrammatic of the body connections that may be used by the various subsystems included in the overall system 108. The return electrodes may be one or more patch electrodes 18 (body electrodes) or any other type of electrode suitable for use as a return electrode including, for example, one or more catheter shaft electrodes or arm electrodes. Return electrodes that are catheter electrodes may be arm electrodes, catheter shaft electrodes or part of a separate catheter or device (not shown).

[0132] The electrodes 200, 202, 204 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 136). The ablation generator 124 generates ablative energy which is delivered by the catheter 100 to the tissue, to form lesions in the tissue or cause electroporation, for example. All electrodes 200, 202, 204 of the catheter 100 may deliver an electric current simultaneously. Alternatively, stimulation is delivered between pairs of electrodes on the catheter. For example, electric fields may be applied between pairs of the first arm electrodes (e.g. in a bipolar approach), between pairs of the second arm electrodes (e.g. in a bipolar approach), or between the first arm electrodes and / or second arm electrodes and a return patch (e.g. in a monopolar approach). Delivering electric current simultaneously using a plurality of electrodes (e.g., from all electrodes of the first arm orfrom all second arm electrodes) may facilitate creating a sufficiently deep lesion for electroporation. To facilitate activating electrodes simultaneously, the electrodes may be switchable between being connected to a 3D mapping system and being connected to EP amplifiers.

[0133] The shape-changing catheter 100 can be used in conjunction with any suitable medical device localization system, such as those referenced and / or described herein. For example, the shape-changing catheter 100 can be used in conjunction with the catheter localization systems and methods described in U.S. Patent Pub. No. 2020 / 0138334 Al entitled “Method for Medical Device Localization based on Magnetic and Impedance Sensors”, the entire disclosure of which is incorporated herein by reference.

[0134] Various embodiments described herein may find use in navigation applications that use real-time and / or pre-acquired images of a region of interest. Therefore, the system 108 may optionally include the image database 118 to store image information relating to the patient’s body. Image information may include, for example, a region of interest surrounding a destination site for the shape-changing catheter 100 and / or multiple regions of interest along a navigation path contemplated to be traversed by the shape-changing catheter 100. The data in the image database 118 may include known image types including (1) one or more two-dimensional still images acquired at respective, individual times in the past; (2) a plurality of related two-dimensional images obtained in real-time from an image acquisition device (e.g., fluoroscopic images from an x-ray imaging apparatus), wherein the image database 118 acts as a buffer (live fluoroscopy); and / or (3) a sequence of related two- dimensional images defining a cine-loop wherein each image in the sequence has at least an ECG timing parameter associated therewith, adequate to allow playback of the sequence in accordance with acquired real-time ECG signals obtained from the ECG monitor 120. It should be understood that the foregoing embodiments are examples only and not limiting in nature. For example, the image database 118 may also include three-dimensional image data as well. It should be further understood that the images may be acquired through any imaging modality, now known or hereafter developed, for example X-ray, ultra-sound, computerized tomography, nuclear magnetic resonance or the like.

[0135] The ECG monitor 120 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 generallycorresponds 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) stored in the database 118. The ECG monitor 120 and ECG electrodes may both include conventional components.

[0136] Another medical positioning system sensor, namely, a patient reference sensor (PRS) 126 (if provided in the system 108) can be configured to provide a positional reference of the patient’s body so as to allow motion compensation for patient body movements, such as respiration-induced movements. Such motion compensation is described in greater detail in U.S. Patent Application Ser. No. 12 / 650,932, entitled “Compensation of Motion in a Moving Organ Using an Internal Position Reference Sensor”, hereby incorporated by reference in its entirety as though fully set forth herein. The PRS 126 may be attached to the patient’s manubrium sternum or other location.

[0137] The medical positioning system 122 is configured to serve as the localization system and therefore to determine position (localization) data with respect to the one or more location sensors 106, 107 and / or the electrodes 200, 202, 204 and output a respective location reading. In an embodiment, the medical positioning system 122 may include a first medical positioning system or an electrical impedance-based medical positioning system 122A that determines locations of the electrodes 200, 202, 204 in a first coordinate system, and a second medical positioning system or magnetic field-based medical positioning system 122B that determines location(s) of the location sensor(s) 106, 107 in a second coordinate system. In an embodiment, the location readings may each include at least one or both of a position and an orientation (P&O) relative to a reference coordinate system (e.g., magnetic based coordinate system or impedance-based coordinate system). For some types of sensors, the P&O may be expressed with five degrees-of- freedom (five DOF) as a three-dimensional (3D) position (e.g., a coordinate in three perpendicular axes X, Y and Z) and two-dimensional (2D) orientation (e.g., a pitch and yaw) of the location sensor(s) 106, 107 in a magnetic field relative to a magnetic field generator(s) or transmitted s) and / or the electrodes 200, 202, 204 in an applied electrical field relative to an electrical field generator (e.g., a set of electrode patches). For other sensor types, the P&O may be expressed with six degrees-of-freedom (six DOF) as a 3D position (e.g., X, Y, Z coordinates) and 3D orientation (e.g., roll, pitch, and yaw). The PRS 126 can be configured to detect one or more characteristics of the magnetic field in which it is disposed, wherein medical positioning system 122 determines a locationreading (e.g., a P&O reading) indicative of the PRS’s position and orientation in the magnetic reference coordinate system.

[0138] The impedance based medical positioning system 122 A determines locations of the electrodes 200, 202, 204 based on capturing and processing signals received from the electrodes 360, 370 and external electrode patches while the electrodes 360, 370 are disposed in a controlled electrical field (e.g., potential field) generated by the electrode patches, for example. FIG. 1 also illustrates a diagrammatic overview of an exemplary embodiment of the electrical impedance-based medical positioning system (‘MPS system’) 122A. The MPS system 122A may include various visualization, mapping and navigation components as known in the art, including, for example, an EnSite™ X EP System commercially available from Abbott Laboratories or as seen generally by reference to U.S. Patent No. 7,263,397 entitled “Method and Apparatus for Catheter Navigation and Location and Mapping in the Heart” to Hauck et al., or U.S. Patent Pub. No. 2007 / 0060833 Al to Hauck entitled “Method of Scaling Navigation Signals to Account for Impedance Drift in Tissue”, both owned by the common assignee of the present invention, and both hereby incorporated by reference in their entireties.

[0139] The magnetic field-based medical positioning system 122B determines locations (e.g., P&O) of the location sensor(s) 106, 107 in a magnetic coordinate system based on capturing and processing signals received from the location sensor(s) 106, 107 while the location sensor is disposed in a controlled low-strength alternating current (AC) magnetic field. Each location sensor 106, 107 and the like may include a coil and, from an electromagnetic perspective, the changing or AC magnetic field may induce a current in the coil(s) when the coil(s) are in the magnetic field. The location sensor(s) 106, 107 is thus configured to detect one or more characteristics (e.g., flux) of the magnetic field(s) in which it is disposed and generate a signal indicative of those characteristics, which is further processed by medical positioning system 122B to obtain a respective P&O for the location sensor(s) 106, 107 relative to, for example, a magnetic field generator.

[0140] It should be understood that the shape-changing catheter 100 may be used for any other suitable diagnostic and / or therapeutic purposes. Accordingly, the shape-changing catheter 100 can be configured to perform ablation procedures, cardiac mapping, electrophysiological (EP) studies and other diagnostic and / or therapeutic procedures. Embodiments are not limited to any one type of catheter or catheter-based system orprocedure.

[0141] Figures 2A to 2D show a flexible tip portion 10 of a catheter 100 of a first aspect in a first non-expanded configuration (without the inflatable balloon shown), where figure 2D illustrates the catheter 100 with an inflatable ballon 300 in situ. The flexible tip portion 10 is at the distal end of the catheter shaft 136. In this embodiment, the flexible tip portion 10 comprises eight electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 forming an expandable flexible framework on which 28 ring electrodes 200, 204 are mounted (a “paddle structure”).

[0142] The electrode-carrying arms comprise a first outboard arm 186, second outboard arm 196, first mid-board arm 188, second mid-board arm 198 and four inboard arms 182, 184, 192, 194. Each electrode-carrying arm 182, 184, 186, 188, 192, 194, 196, 198 extends from a distal end of the catheter shaft. A proximal coupler 206 is mounted on the distal end of the catheter shaft 136 and the proximal portion of each electrode-carrying arm 182, 184, 186, 188, 192, 194, 196, 198 extends through the proximal coupler 206. Each electrode-carrying arm 182, 184, 186, 188, 192, 194, 196, 198 exits from a distal end of the proximal coupler 206. Each electrode-carrying arm 182, 184, 186, 188, 192, 194, 196, 198 converges at a distal apex of the flexible tip portion 10.

[0143] Four of the ring electrodes 204, located on the first outboard arm 186, second outboard arm 196, first mid-board arm 188 and second mid-board arm 198, are slightly longer than the other electrodes. Each longer electrode 204 is on a shoulder of the first outboard arm 186, second outboard arm 196, first mid-board arm 188 and second mid-board arm 198, and is the most-distal ring electrode on the respective arm. Each of the eight electrode-carrying arms carries three small ring electrodes 200, spaced along its length. The eight electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 are designed to maintain the 24 ring electrodes 200 in a spaced relationship so that each small ring electrode 200 can capture separate data about the electrical activity of the cardiac tissue adjacent to the electrodes.

[0144] A distal coupler comprising a distal electrode 202 is included at the distal apex of the flexible tip portion 10 where the eight electrode-carrying arms come together.

[0145] Each of the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 has a shape-memory under structure. The expandable flexible framework has a first non-expanded configuration and a second expanded configuration.

[0146] In the first non-expanded configuration, shown in figures 2A to 2C the flexible, substantially planar array of arms 182, 184, 186, 188, 192, 194, 196, 198 causes electrodes 200, 204 to conform to tissue. The non-expanded flexible framework is configured to facilitate relative movement among at least some of the electrodes 200, 204 relative to other of the electrodes 200, 204. The eight arms 182, 184, 186, 188, 192, 194, 196, 198 make two “halves” of the expandable flexible framework structure. The first and second outboard arms 186, 196 are shared between both halves. The first half comprises one mid-board arm 188 and two inboard arms 182, 184. The second half comprises one mid-board arm 198 and two inboard arms 192, 194. As shown in figure 2B and 2C, the inboard and mid-board arms of the first half 182, 184, 188 may be stacked on top of the inboard and mid-board arms of the second half 192, 194, 198. The substantially planar array is planar in that a plane passes through the centers of the first and second outboard arms 186, 196 and contacts the circumference of the two mid-board 188, 198 and four inboard arms 182, 184, 192, 194. In the first non-expanded configuration, one half of the flexible framework contacts the tissue. That is, five electrode-carrying arms 182, 184, 186, 188, 196 or 186, 192, 194, 196, 198 may contact the tissue for high-density mapping.

[0147] The electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 are configured to maintain the electrodes 200 in a spaced relationship such that each of the electrodes 200 can capture separate data about the electrical activity of cardiac tissue adjacent to the plurality of electrodes.

[0148] Figure 2D shows the first non-expanded configuration with the inflatable balloon 300 in situ. The inflatable balloon 300 is positioned between the two “halves” of the expandable flexible framework structure. As shown, mid-board arm 188 and inboard arms 182, 184 are positioned on a first side of the inflatable balloon 300, and mid-board arm 198 and inboard arms 192, 194 are positioned on a second side of the inflatable balloon 300 (not shown).

[0149] Figures 3A to 3C show a flexible tip portion 10 of a catheter of the first aspect in a second expanded configuration (without the inflatable balloon shown). The second expanded configuration secures a position of the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 in an expanded array. The plurality of electrodes 200, 204 form an expanded electrode array. In the second expanded configuration a volume is created between the two halves of the expandable flexible framework structure. The inboard and mid-board arms of the first half 182, 184, 188 are spatially separated from the inboard and mid-board arms of the second half 192, 194, 198, as shown in figures 3B and 3C.

[0150] The distal coupler electrode (distal electrode) 202 is in-plane or near to in-plane with the longer electrodes 204 in the second expanded configuration. The longer electrodes 204 and the distal electrode 202 can be used to ablate, for example, with the catheter shaft 136 perpendicular to the tissue surface.

[0151] While figures 2 and 3 illustrate electrodes 200, 204 which are ring electrodes, as shown in figures 4A and 4B, the electrodes 200, 204 may alternatively or additionally comprise spot electrodes or flexible electrodes. Electrode-carrying arms 182, 184, 188, 192, 194, 198 may be one-sided, such that the electrodes 200, 240 are mounted only on one surface (or side) of the electrode-carrying arms 182, 184, 188, 192, 194, 198. Each electrodecarrying arm 182, 184, 188, 192, 194, 198 comprises an outward-facing surface (facing the exterior of the expandable flexible framework) and an inward-facing surface (facing the interior of the expandable flexible framework). The electrodes 200, 204 are mounted on the outward-facing surface (facing the exterior of the expandable flexible framework) of electrode-carrying arms 182, 184, 188, 192, 194, 198. Electrode-carrying arms 186, 196 comprise ring electrodes 200, 204.

[0152] The most distal electrodes 204 on the shoulder of the mid-board electrode-carrying arms 188, 198 can be shorted together to act as a single, longer microelectrode. This singlesided electrode array can be used with or without an inflatable balloon 300 (i.e. using a mechanical expansion mechanism).

[0153] Figures 5 A to 5C show a flexible tip portion 10 of a catheter of the first aspect in a second expanded configuration with an inflatable balloon 300 in situ to selectively expand the expandable flexible framework. The balloon 300 is inflated to occupy the space between the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198. A proximal end 304 of the balloon is fixed to a distal end 136 of the catheter shaft. A distal end 306 of the balloon is fixed to the distal apex of the flexible tip portion 10.

[0154] The catheter shaft 136 comprises a fluid delivery lumen (not shown) adapted to be fluidly coupled to a source of irrigant and adapted to deliver the irrigant to the inflatable balloon 300. The irrigation fluid is used to inflate the inflatable balloon 300.

[0155] The inflatable balloon 300 may comprise eight channels 302 as shown in figures 6A to 6D. Each channel 302 extends from a proximal end 304 of the balloon to a distal end 306 of the balloon. Each channel 302 is configured to receive one of the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198. As shown in figures 6B and 6D, each channel 302 has a curved shape to receive one of the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198. The channels 302 facilitate holding the arms 182, 184, 186, 188, 192, 194,196, 198 in a secure position when the balloon 300 is inflated and the flexible framework is in the second expanded configuration.

[0156] Figures 7A and 7B show a flexible tip portion 10 of a catheter 100 according to a second aspect of the invention with a mechanical expansion mechanism, in a second expanded configuration. The flexible tip portion 10 is at the distal end of the catheter shaft 136. The flexible tip portion 10 comprises eight electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 forming an expandable flexible framework on which 30 electrodes 200, 204 are mounted.

[0157] The electrode-carrying arms comprise a first outboard arm 186, second outboard arm 196, first mid-board arm 188, second mid-board arm 198 and four inboard arms 182, 184, 192, 194. Each electrode-carrying arm 182, 184, 186, 188, 192, 194, 196, 198 extends from a distal end of the catheter shaft. A proximal coupler 206 is mounted within the distal end of the catheter shaft 136. Each electrode-carrying arm 182, 184, 186, 188, 192, 194, 196, 198 exits from a distal end of the proximal coupler 206. Each electrode-carrying arm 182, 184, 186, 188, 192, 194, 196, 198 converges at a distal apex of the flexible tip portion 10. A distal coupler comprising a distal electrode 202 is included at the distal apex of the flexible tip portion 10 where the eight electrode-carrying arms come together.

[0158] The electrodes 200 on the outboard arms 186, 196 are ring electrodes. The electrodes 200 mounted on the outward-facing surface (facing the exterior of the expandable flexible framework) of inboard and mid-board electrode-carrying arms 182, 184, 188, 192, 194, 198 are spot electrodes. The ring electrodes 204, located on the first outboard arm 186 and second outboard arm 196 are slightly longer than the other ring electrodes. In addition, the two most distal spot electrodes 204 on the shoulder of each of the mid-board electrodecarrying arms 188, 198 are shorted together to act as a single, longer microelectrode.

[0159] Each of the eight electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 carries three small electrodes 200 (ring or spot electrodes), spaced along its length. The eight electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 are designed to maintain the electrodes 200 in a spaced relationship so that each small electrode 200 can capture separate data about the electrical activity of the cardiac tissue adjacent to the electrodes 200.

[0160] Each of the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 has a shape-memory under structure. The expandable flexible framework has a first non-expanded configuration and a second expanded configuration.

[0161] An expansion control member 400 comprises an inner shaft member having a distal end 404 coupled to the distal apex of the flexible tip portion 10. The inner shaft member 400is slidably positioned within the catheter shaft 100. A control mechanism in the handle 110 (not shown) is drivingly coupled with the distal apex via the expansion control member 400 and is operable to move the expansion control member 400 distally relative to the catheter shaft 100 to collapse the expandable flexible framework from the second expanded configuration to the first non-expanded configuration and move the expansion control member 400 proximally relative to the catheter shaft to radially outwardly expand the expandable flexible framework from the first non-expanded configuration to the second expanded configuration.

[0162] The second expanded configuration secures a position of the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 in an expanded array. The plurality of electrodes 200, 204 form an expanded electrode array. In the second expanded configuration a volume is created between the two halves of the expandable flexible framework structure. The inboard and mid-board arms of the first half 182, 184, 188 are spatially separated from the inboard and mid-board arms of the second half 192, 194, 198, as shown in figures 7 A and 7B. The distal end of the catheter shaft 136 includes a distal shaft electrode 360 and a proximal shaft electrode 370 mounted on the shaft, and location sensors 106, 107 (for example, two offset magnetic field sensors) within the shaft.

[0163] Figures 8A and 8B show a perspective view of the distal end of the catheter shaft 136, with a plurality of irrigation holes 320 at the distal end of proximal coupler 206 (although irrigation holes 320 could be at the distal end of the proximal coupler cap 208, where present). The electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 exit the distal end of the proximal coupler 206. A fluid delivery lumen (not shown) is in fluid communication with each of the irrigation holes 320. The fluid delivery lumen is adapted to be fluidly coupled to a source of irrigant and to deliver the irrigant through the plurality of irrigation holes 320, adjacent to the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 and thus the array of electrodes 200. Where a proximal coupler cap 208 is present, the irrigation holes 320 may be located at the distal end of the coupler cap 208 (not shown).

[0164] Figure 9 shows a perspective view of the distal end of the catheter shaft 136. An alternative irrigation mechanism comprises an offset / space 340 between the outer circumference of the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 and the proximal coupler 206 (or proximal coupler cap 208). The space 340 created between the coupler 206 and the arms 182, 184, 186, 188, 192, 194, 196, 198 allows irrigant to be delivered adjacent to the arms, facilitating bulk irrigation.

[0165] Figure 10 is a cross-section through a flexible tip portion 10 according to a first aspect of the invention having an alternative irrigation mechanism. Specifically, a crosssection through the inflatable balloon 300 and expandable flexible framework in the second expanded configuration is shown. A fluid delivery lumen (not shown) is in fluid communication with an irrigation hole 320 located at the distal end of the proximal coupler cap 208. The irrigation hole 320 is centered relative to the exit of the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 from the proximal coupler cap 208. The irrigation hole 320 is located inside the cavity of the inflatable balloon 300. The fluid delivery lumen is adapted to be fluidly coupled to a source of irrigant and to deliver the irrigant through the irrigation hole 320, and into the inflatable balloon 300. The irrigation fluid can be used to inflate the inflatable balloon 300.

[0166] Figure 11 is a sectional view of the distal end of the catheter shaft 136 showing the positions of the proximal coupler 206, location sensors 106, 107 (for example, two offset magnetic field sensors), distal shaft electrode 360 and proximal shaft electrode 370. The proximal coupler 206 comprises a proximal coupler cap 208 and a proximal coupler stem 210. The proximal coupler stem 210 is located within the distal portion of the catheter shaft. The proximal coupler cap 208 receives the proximal coupler stem 210. The proximal coupler cap 208 is electrically active (an electrode) and is located at the most distal part of the catheter shaft and two further ring electrodes 360, 370 are positioned on the catheter shaft 136: a distal shaft electrode 360 and a proximal shaft electrode 370. The distal shaft electrode 360 may be approximately 2.5 mm from the distal end of the proximal coupler cap 208 and the proximal shaft electrode 370 may be spaced approximately 4 mm from the distal shaft electrode 360. The location sensors 106, 107 are mounted in the catheter shaft lumen, just proximal to the proximal coupler 206.

[0167] Figure 12 depicts the catheter against tissue 500 in the first non-expanded configuration in which the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 form a flexible, substantially planar array and bring electrodes 200, 204 into contact with tissue. The substantially planar array is able to flex and bend when contacting the surface of the tissue 500, adapting to conform to tissue and enabling a physician to maintain contact between several of the electrodes 200 and the tissue. This enhances the accuracy, and the corresponding diagnostic value, of the recorded information concerning the heart's electrical activity. This also maintains contact for ablation while in the non-expanded, substantially planar configuration.

[0168] Figure 13 A depicts the catheter against tissue 500 in the second expanded configuration in which the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 form a flexible expanded array, and expanded array electrodes 200, 204 (the expandable flexible framework is shown but no inflatable balloon or expansion control member). The longer electrodes 204 and the distal electrode 202 (at the distal apex) can be used for focal ablation with the catheter shaft perpendicular to the surface of the tissue 500. This is useful in ablating hard-to-reach regions (e.g. the posterior heart walls) without having to reach the location with the shaft parallel to the wall.

[0169] Figure 13B depicts the catheter against tissue 500 in a vein for PVI ablations in the second expanded configuration in which the electrode-carrying arms 182, 184, 186, 188, 192, 194, 196, 198 form a flexible expanded array, and expanded array of electrodes 200, 204. Radially arranged electrodes 200 may contact the vein and can be used for “single shot” pulmonary vein ablations, or Pulmonary Vein Isolation (PVI).

[0170] Although the catheters have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed catheters without departing from the spirit of the present disclosure. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the present teachings. The foregoing description and following claims are intended to cover all such modifications and variations.

[0171] 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 invention, 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.

[0172] 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 totreat 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.

[0173] 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 invention.

[0174] 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:

[0175] 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 extending between the proximal end and the distal end; and a flexible tip portion at the distal end of the catheter shaft, the flexible tip portion comprising: an expandable 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 arm converges with at least one other of the plurality of electrode-carrying arm at a distal apex of the flexible tip portion and wherein each of the plurality of electrode-carrying arms comprises a shape-memory material; a plurality of electrodes mounted on the electrode-carrying arms; and an inflatable balloon positioned within the expandable flexible framework formed from the plurality of electrode-carrying arms, the balloon selectively inflatable to adjust the expandable flexible framework from a first non-expanded configuration in which the plurality of electrode-carrying arms form a flexible, substantially planar array, to a second expanded configuration securing a position of the plurality of electrode-carrying arms in an expanded array.

[0176] Clause 2. The catheter of clause 1, wherein the flexible tip portion is configured to prevent longitudinal movement between the electrode-carrying arms and the distal end of the catheter shaft.

[0177] Clause 3. The catheter of clause 1 or clause 2, wherein a proximal coupler is mounted on or within the distal end of the catheter shaft, optionally wherein the proximal portion of each of the electrode-carrying arms extends through the proximal coupler and wherein each electrode-carrying arm exits from a distal end of the proximal coupler.

[0178] Clause 4. The catheter of any of clauses 1 to 3, wherein at least a portion of each of the plurality of electrode-carrying arms are covered with a nonconductive material configured to insulate each of the plurality of electrodes from other of the plurality of electrodes.

[0179] Clause 5. The catheter of any of clauses 1 to 4, wherein the plurality of electrode-carrying arms are longitudinally-extending and laterally separated electrodecarrying arms, optionally extending parallel to the catheter shaft longitudinal axis.

[0180] Clause 6. The catheter of any of clauses 1 to 5, wherein the plurality of electrode-carrying arms lie in a plane in the first non-expanded configuration.

[0181] Clause 7. The catheter of any of any preceding clause, wherein the expandable flexible framework comprises between four and 16 electrode-carrying arms, optionally 8 electrode-carrying arms.

[0182] Clause 8. The catheter of any preceding clause, wherein the plurality of electrodes are equally spaced along each of the plurality of electrode-carrying arms.

[0183] Clause 9. The catheter of any preceding clause, wherein the plurality of electrodes comprises between four and sixty-four individual electrodes, optionally 32 electrodes.

[0184] Clause 10. The catheter of any preceding clause, wherein at least some of the plurality of electrodes are ring, spot, or flexible electrodes.

[0185] Clause 11. The catheter of any of clauses 1 to 10, wherein the electrodes are arranged on the electrode-carrying arms and configured for contacting tissue on a front side and a back side of the substantially planar array when in the first non-expanded configuration.

[0186] Clause 12. The catheter of any preceding clause, wherein the plurality of electrodes are configured for use as mapping electrodes.

[0187] Clause 13. The catheter of any preceding clause, wherein a separate electrical lead wire or conductive trace is electrically coupled to each electrode in the plurality of electrodes.

[0188] Clause 14. The catheter of any preceding clause, wherein the plurality of electrodes are arranged in a plurality of rows, wherein each row is distributed along a different one of the plurality of electrode-carrying arms and the plurality of rows is aligned parallel to the catheter shaft longitudinal axis.

[0189] Clause 15. The catheter of clause 14, wherein the plurality of electrode-carrying arms are configured to maintain the plurality of electrodes in the plurality of rows in a spacedrelationship 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.

[0190] Clause 16. The catheter of any one of clauses 1 to 15, wherein the electrodes are all the same size.

[0191] Clause 17. The catheter of any one of clauses 14 to 16, wherein four electrodes of the plurality of electrodes are placed and configured as localization and focal ablation electrodes, and wherein each of these four localization and focal ablation electrodes is placed among a different row of the plurality of rows of electrodes.

[0192] Clause 18. The catheter of any one of clauses 1 to 15, wherein the plurality of electrode-carrying arms comprises a first outboard arm, a second outboard arm, a first midboard arm and a second mid-board arm, each arm having an electrode slightly longer than the other electrodes, optionally wherein each longer electrode is on a shoulder of the arm.

[0193] Clause 19. The catheter of any one of clauses 1 to 18, further comprising a distal coupler at the distal apex of the flexible tip portion.

[0194] Clause 20. The catheter of clause 19, wherein the distal coupler is configured to be electrically active, optionally wherein the distal coupler is a distal electrode.

[0195] Clause 21. The catheter of any of clauses 19 or 20, wherein the inflatable balloon is shaped such that the distal coupler is in-plane or near to in-plane with the longer electrodes when the flexible framework is in the second expanded configuration.

[0196] Clause 22. The catheter of any preceding clause, wherein the plurality of electrodes are configured for use in unipolar, bipolar or omnipolar measurements or ablation.

[0197] Clause 23. The catheter of any preceding clause, further comprising at least one internal, longitudinally-extending fluid delivery lumen adapted to be fluidly coupled to a source of irrigant, wherein the catheter comprises at least one irrigation hole in fluid communication with the at least one fluid delivery lumen.

[0198] Clause 24. The catheter of clause 23, wherein the fluid delivery lumen is adapted to deliver the irrigant through the at least one irrigation hole on or adjacent to the array of electrodes, and / or wherein the fluid delivery lumen is adapted to deliver the irrigant through the at least one irrigation hole to the inflatable balloon.

[0199] Clause 25. The catheter of any preceding clause further comprising: a handle comprising a control mechanism; and an expansion control member as part of the flexible expandable framework, the expansion control member drivingly coupled with the control mechanism and operable to collapse the expandable flexible framework from the second expanded configuration to thefirst non-expanded configuration and to expand the expandable flexible framework radially outwardly from the first non-expanded configuration to the second expanded configuration, wherein a distal end of the inflatable balloon is coupled to the distal apex.

[0200] Clause 26. The catheter of clause 25, wherein the expansion control member comprises an inner shaft member slidably positioned within the catheter shaft and through the interior of the balloon, wherein a distal end of the inner shaft member is coupled to the distal end of the inflatable balloon or to the distal apex.

[0201] Clause 27. The catheter of clause 25, wherein the expansion control member comprises a pull wire located along at least two of the electrode-carrying arms.

[0202] Clause 28. The catheter of clause 26 or 27, wherein the expansion control member comprises a rigid or semi-rigid polymer, or a flexible metal, optionally stainless steel.

[0203] Clause 29. The catheter of any of clauses 25 to 28, wherein the handle further comprises a selective movement limiter operable to limit movement of the expansion control member relative to the catheter shaft, optionally wherein the selective movement limiter comprises a clamp engageable with the expansion control member.

[0204] Clause 30. The catheter of any of any preceding clause, wherein the inflatable balloon comprises a plurality of channels, wherein each channel is configured to receive one of the plurality of electrode-carrying arms.

[0205] Clause 31. The catheter of any preceding clause, further comprising at least one electrode mounted on or within the distal end of the catheter shaft adjacent to the flexible tip portion, optionally wherein the electrode is a ring, spot, or flexible electrode.

[0206] Clause 32. The catheter of any preceding clause when dependent on clause 3, further comprising a proximal coupler cap, wherein a) the proximal coupler cap is configured to be electrically active, and / or b) the catheter further comprises at least one electrode mounted on the proximal coupler or proximal coupler cap.

[0207] Clause 33. The catheter of any preceding clause, further comprising at least one location sensor.

[0208] Clause 34. The catheter of clause 33, wherein the at least one location sensor is mounted in or on at least one of the following: the catheter shaft; or the distal end of the flexible tip portion.

[0209] Clause 35. The catheter of clause 33 or 34, wherein the at least one location sensor is a magnetic field sensor.

[0210] Clause 36. The catheter of any preceding clause, further comprising a temperature sensor.

[0211] Clause 37. A catheter comprising: a handle comprising a control mechanism; a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis extending between the proximal end and the distal end; a flexible tip portion at the distal end of the catheter shaft, the flexible tip portion comprising: an expandable 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 arm converges with at least one other of the plurality of electrode-carrying arm at a distal apex of the flexible tip portion and wherein each of the plurality of electrode-carrying arms comprises a shape-memory material, wherein the expandable flexible framework has a first non-expanded configuration and a second expanded configuration; a plurality of electrodes mounted on the electrode-carrying arms, wherein in the first non-expanded configuration the plurality of electrode-carrying arms form a flexible, substantially planar array, and wherein the second expanded configuration secures a position of the plurality of electrode-carrying arms in an expanded array; and an expansion control member having a distal end coupled to the distal apex, wherein the control mechanism is drivingly coupled with the distal apex via the expansion control member and operable to move the expansion control member distally relative to the catheter shaft to collapse the expandable flexible framework from the second expanded configuration to the first non-expanded configuration and move the expansion control member proximally relative to the catheter shaft to radially outwardly expand the expandable flexible framework from the first non-expanded configuration to the second expanded configuration.

[0212] Clause 38. A catheter according to clause 37, wherein the expansion control member comprises an inner shaft member slidably positioned within the catheter shaft, wherein a distal end of the inner shaft member is coupled to the distal apex.

[0213] Clause 39. The catheter of clause 37 or 38, wherein the expansion control member comprises a pull wire located along at least two of the electrode-carrying arms, wherein each pull wire has a distal end coupled to the distal apex and a proximal end coupled to the control mechanism.

[0214] Clause 40. The catheter of clause 37 to 39, wherein the handle further comprises a selective movement limiter operable to limit movement of the expansion control member relative to the catheter shaft, optionally wherein the selective movement limiter comprises a clamp engageable with the expansion control member.

[0215] Clause 41. The catheter of clause 40, wherein the clamp comprises a first portion and a second portion, where the first portion is in a fixed position and the second portion is movable relative to the first portion to allow engagement with the expansion control member, or wherein the clamp comprises a first portion and a second portion, where the first portion and the second portion are movable to allow engagement with the expansion control member.

[0216] Clause 42. The catheter of any of clauses 37 to 41, wherein the expansion control member is further configured to adjust a stiffness of the expandable flexible framework, from a first stiffness to a second stiffness, and maintain the first stiffness or the second stiffness when the selective movement limiter couples with the expansion control member and limits a longitudinal movement of the expansion control member.

[0217] Clause 43. The catheter of clause 42, wherein: the expansion control member is configured to move freely when the selective movement limiter is not coupled with the expansion control member; and optionally wherein the selective movement limiter is configured as a clamp where the clamp engages the expansion control member and limits the longitudinal movement of the expansion control member.

[0218] Clause 44. The catheter of any of clauses 37 to 43, wherein the flexible tip portion is configured to prevent longitudinal movement between the electrode-carrying arms and the distal end of the catheter shaft.

[0219] Clause 45. The catheter of any of clauses 37 to 44, wherein a proximal coupler is mounted on or within the distal end of the catheter shaft, optionally wherein the proximal portion of each of the electrode-carrying arms extends through the proximal coupler and wherein each electrode-carrying arm exits from a distal end of the proximal coupler.

[0220] Clause 46. The catheter of any of clauses 37 to 45, wherein the plurality of electrode-carrying arms are longitudinally-extending and laterally separated electrodecarrying arms, optionally extending parallel to the catheter shaft longitudinal axis.

[0221] Clause 47. The catheter of any of clauses 37 to 46, wherein the plurality of electrode-carrying arms lie in a plane in the first non-expanded configuration.

[0222] Clause 48. The catheter of any of clauses 37 to 47, wherein the expandable flexible framework comprises between four and 16 electrode-carrying arms, optionally 8 electrode-carrying arms.

[0223] Clause 49. The catheter of any of clauses 37 to 48, wherein the plurality of electrodes are equally spaced along each of the plurality of electrode-carrying arms.

[0224] Clause 50. The catheter of any of clauses 37 to 49, wherein at least some of the plurality of electrodes are ring, spot, or flexible electrodes.

[0225] Clause 51. The catheter of any of clauses 37 to 50, wherein the electrodes are arranged on the electrode-carrying arms and configured for contacting tissue on a front side and a back side of the substantially planar array when in the first non-expanded configuration.

[0226] Clause 52. The catheter of any of clauses 50 to 51, wherein the plurality of electrode-carrying arms comprises a first outboard arm, a second outboard arm, a first midboard arm and a second mid-board arm, and four inboard arms, wherein the plurality of electrodes on the first mid-board arm, second mid-board arm, and four inboard arms are mounted on outward-facing surfaces of the electrode-carrying arms, optionally wherein the electrodes on the first and second outboard arms are ring, spot, or flexible electrodes.

[0227] Clause 53. The catheter of any of clauses 37 to 52, wherein a separate electrical lead wire or conductive trace is electrically coupled to each electrode in the plurality of electrodes.

[0228] Clause 54. The catheter of any of clauses 37 to 53, wherein the plurality of electrodes are arranged in a plurality of rows, wherein each row is distributed along a different one of the plurality of electrode-carrying arms and the plurality of rows is aligned parallel to the catheter shaft longitudinal axis.

[0229] Clause 55. The catheter of clause 54, wherein the plurality of electrode-carrying arms are 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.

[0230] Clause 56. The catheter of any of clauses 37 to 55, wherein the electrodes are all the same size.

[0231] Clause 57. The catheter of any of clauses 54 to 56, wherein four electrodes of the plurality of electrodes are placed and configured as localization and focal ablation electrodes, and wherein each of these four localization and focal ablation electrodes is placed among a different row of the plurality of rows of electrodes.

[0232] Clause 58. The catheter of any of clauses 37 to 55, wherein the plurality of electrode-carrying arms comprises a first outboard arm, a second outboard arm, a first midboard arm and a second mid-board arm, each having an electrode slightly longer than the other electrodes, optionally wherein each longer electrode is on a shoulder of the arm.

[0233] Clause 59. The catheter of any of clauses 37 to 58, further comprising a distal coupler at the distal apex of the flexible tip portion.

[0234] Clause 60. The catheter of clause 59, wherein the distal coupler is configured to be electrically active, optionally wherein the distal coupler is a distal electrode.

[0235] Clause 61. The catheter of any of clauses 37 to 60, wherein the plurality of electrodes are configured for use in unipolar, bipolar or omnipolar measurements or ablation.

[0236] Clause 62. The catheter of any of clauses 37 to 61, further comprising at least one internal, longitudinally-extending fluid delivery lumen adapted to be fluidly coupled to a source of irrigant, wherein the catheter comprises at least one irrigation hole in fluid communication with the at least one fluid delivery lumen.

[0237] Clause 63. The catheter of clause 62, wherein the fluid delivery lumen is adapted to deliver the irrigant through the at least one irrigation hole on or adjacent to the array of electrodes.

[0238] Clause 64. The catheter of any of clauses 37 to 62, further comprising at least one electrode mounted on or within the distal end of the catheter shaft adjacent to the flexible tip portion, optionally wherein the electrode is a ring, spot, or flexible electrode.

[0239] Clause 65. The catheter of any of clauses 37 to 64 when dependent on clause 45, further comprising a proximal coupler cap, wherein a) the proximal coupler cap is configured to be electrically active, and / or b) the catheter further comprises at least one electrode mounted on the proximal coupler or proximal coupler cap.

[0240] Clause 66. The catheter of any of clauses 37 to 65, further comprising at least one location sensor.

[0241] Clause 67. The catheter of clause 66, wherein the at least one location sensor is mounted in or on at least one of the following: the catheter shaft; or the distal end of the flexible tip portion.

[0242] Clause 68. The catheter of clause 66 or 67, wherein the at least one location sensor is a magnetic field sensor.

[0243] Clause 69. The catheter of any of clauses 37 to 68, further comprising a temperature sensor.

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 extending between the proximal end and the distal end; and a flexible tip portion at the distal end of the catheter shaft, the flexible tip portion comprising: an expandable 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 arm converges with at least one other of the plurality of electrode-carrying arm at a distal apex of the flexible tip portion and wherein each of the plurality of electrode-carrying arms comprises a shape-memory material; a plurality of electrodes mounted on the electrode-carrying arms; and an inflatable balloon positioned within the expandable flexible framework formed from the plurality of electrode-carrying arms, the balloon selectively inflatable to adjust the expandable flexible framework from a first non-expanded configuration in which the plurality of electrode-carrying arms form a flexible, substantially planar array to a second expanded configuration securing a position of the plurality of electrode-carrying arms in an expanded array.

2. The catheter of claim 1, wherein the flexible tip portion is configured to prevent longitudinal movement between the electrode-carrying arms and the distal end of the catheter shaft.

3. The catheter of claim 1 or claim 2, wherein a proximal coupler is mounted on or within the distal end of the catheter shaft, optionally wherein the proximal portion of each of the electrode-carrying arms extends through the proximal coupler and wherein each electrode-carrying arm exits from a distal end of the proximal coupler.

4. The catheter of any of claims 1 to 3, wherein at least a portion of each of the plurality of electrode-carrying arms are covered with a nonconductive material configured to insulate each of the plurality of electrodes from other of the plurality of electrodes.

5. The catheter of any of claims 1 to 4, wherein the plurality of electrodecarrying arms are longitudinally-extending and laterally separated electrode-carrying arms, optionally extending parallel to the catheter shaft longitudinal axis.

6. The catheter of any of claims 1 to 5, wherein the plurality of electrodecarrying arms lie in a plane in the first non-expanded configuration.

7. The catheter of any of any preceding claim, wherein the expandable flexible framework comprises between 4 and 16 electrode-carrying arms, optionally 8 electrodecarrying arms.

8. The catheter of any preceding claim, wherein the plurality of electrodes are equally spaced along each of the plurality of electrode-carrying arms.

9. The catheter of any preceding claim, wherein the plurality of electrodes comprises between four and sixty-four individual electrodes, optionally 32 electrodes.

10. The catheter of any preceding claim, wherein at least some of the plurality of electrodes are ring, spot, or flexible electrodes.

11. The catheter of any of claims 1 to 10, wherein the electrodes are arranged on the electrode-carrying arms and configured for contacting tissue on a front side and a back side of the substantially planar array when in the first non-expanded configuration.

12. The catheter of any preceding claim, wherein the plurality of electrodes are configured for use as mapping electrodes.

13. The catheter of any preceding claim, wherein a separate electrical lead wire or conductive trace is electrically coupled to each electrode in the plurality of electrodes.

14. The catheter of any preceding claim, wherein the plurality of electrodes are arranged in a plurality of rows, wherein each row is distributed along a different one of the plurality of electrode-carrying arms and the plurality of rows is aligned parallel to the catheter shaft longitudinal axis.

15. The catheter of claim 14, wherein the plurality of electrode-carrying arms are configured to maintain the plurality of electrodes in the plurality of rows in a spacedrelationship 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.

16. The catheter of any one of claims 1 to 15, wherein the electrodes are all the same size.

17. The catheter of any one of claims 14 to 16, wherein four electrodes of the plurality of electrodes are placed and configured as localization and focal ablation electrodes, and wherein each of these four localization and focal ablation electrodes is placed among a different row of the plurality of rows of electrodes.

18. The catheter of any one of claims 1 to 15, wherein the plurality of electrodecarrying arms comprises a first outboard arm, a second outboard arm, a first mid-board arm and a second mid-board arm, each arm having an electrode slightly longer than the other electrodes, optionally wherein each longer electrode is on a shoulder of the arm.

19. The catheter of any one of claims 1 to 18, further comprising a distal coupler at the distal apex of the flexible tip portion.

20. The catheter of claim 19, wherein the distal coupler is configured to be electrically active, optionally wherein the distal coupler is a distal electrode.

21. The catheter of any of claims 19 or 20, wherein the inflatable balloon is shaped such that the distal coupler is in-plane or near to in-plane with longer electrodes when the flexible framework is in the second expanded configuration.

22. The catheter of any preceding claim, wherein the plurality of electrodes are configured for use in unipolar, bipolar or omnipolar measurements or ablation.

23. The catheter of any preceding claim, further comprising at least one internal, longitudinally-extending fluid delivery lumen adapted to be fluidly coupled to a source of irrigant, wherein the catheter comprises at least one irrigation hole in fluid communication with the at least one fluid delivery lumen.

24. The catheter of claim 23, wherein the fluid delivery lumen is adapted to deliver the irrigant through the at least one irrigation hole on or adjacent to the electrodes,and / or wherein the fluid delivery lumen is adapted to deliver the irrigant through the at least one irrigation hole to the inflatable balloon.

25. The catheter of any preceding claim further comprising: a handle comprising a control mechanism; and an expansion control member as part of the flexible expandable framework, the expansion control member drivingly coupled with the control mechanism and operable to collapse the expandable flexible framework from the second expanded configuration to the first non-expanded configuration and to expand the expandable flexible framework radially outwardly from the first non-expanded configuration to the second expanded configuration; wherein a distal end of the inflatable balloon is coupled to the distal apex.

26. The catheter of claim 25, wherein the expansion control member comprises an inner shaft member slidably positioned within the catheter shaft and through the interior of the balloon, wherein a distal end of the inner shaft member is coupled to the distal end of the inflatable balloon or to the distal apex.

27. The catheter of claim 25, wherein the expansion control member comprises a pull wire located along at least two of the electrode-carrying arms.

28. The catheter of claim 26 or 27, wherein the expansion control member comprises a rigid or semi-rigid polymer, or a flexible metal, optionally stainless steel.

29. The catheter of any of claims 25 to 28, wherein the handle further comprises a selective movement limiter operable to limit movement of the expansion control member relative to the catheter shaft, optionally wherein the selective movement limiter comprises a clamp engageable with the expansion control member.

30. The catheter of any of any preceding claim, wherein the inflatable balloon comprises a plurality of channels, wherein each channel is configured to receive one of the plurality of electrode-carrying arms.

31. The catheter of any preceding claim, further comprising at least one electrode mounted on or within the distal end of the catheter shaft adjacent to the flexible tip portion, optionally wherein the electrode is a ring, spot, or flexible electrode.

32. The catheter of any preceding claim when dependent on claim 3, further comprising a proximal coupler cap, wherein a) the proximal coupler cap is configured to be electrically active, and / or b) the catheter further comprises at least one electrode mounted on the proximal coupler or proximal coupler cap.

33. The catheter of any preceding claim, further comprising at least one location sensor.

34. The catheter of claim 33, wherein the at least one location sensor is mounted in or on at least one of the following: the catheter shaft; or the distal end of the flexible tip portion.

35. The catheter of claim 33 or 34, wherein the at least one location sensor is a magnetic field sensor.

36. The catheter of any preceding claim, further comprising a temperature sensor.

37. A catheter comprising: a handle comprising a control mechanism; a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis extending between the proximal end and the distal end; a flexible tip portion at the distal end of the catheter shaft, the flexible tip portion comprising: an expandable 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 arm converges with at least one other of the plurality of electrode-carrying arm at a distal apex of the flexible tip portion and wherein each of the plurality of electrode-carrying arms comprises a shape-memory material, wherein the expandable flexible framework has a first nonexpanded configuration and a second expanded configuration; a plurality of electrodes mounted on the electrode-carrying arms, wherein in the first non-expanded configuration the plurality of electrode-carrying arms form a flexible, substantially planar array, and wherein the second expanded configurationsecures a position of the plurality of electrode-carrying arms in an expanded array; and an expansion control member having a distal end coupled to the distal apex, wherein the control mechanism is drivingly coupled with the distal apex via the expansion control member and operable to move the expansion control member distally relative to the catheter shaft to collapse the expandable flexible framework from the second expanded configuration to the first non-expanded configuration and move the expansion control member proximally relative to the catheter shaft to radially outwardly expand the expandable flexible framework from the first non-expanded configuration to the second expanded configuration.

38. A catheter according to claim 37, wherein the expansion control member comprises an inner shaft member slidably positioned within the catheter shaft, wherein a distal end of the inner shaft member is coupled to the distal apex.

39. The catheter of claim 37 or 38, wherein the expansion control member comprises a pull wire located along at least two of the electrode-carrying arms, wherein each pull wire has a distal end coupled to the distal apex and a proximal end coupled to the control mechanism.

40. The catheter of claim 37 to 39, wherein the handle further comprises a selective movement limiter operable to limit movement of the expansion control member relative to the catheter shaft, optionally wherein the selective movement limiter comprises a clamp engageable with the expansion control member.

41. The catheter of claim 40, wherein the clamp comprises a first portion and a second portion, where the first portion is in a fixed position and the second portion is movable relative to the first portion to allow engagement with the expansion control member, or wherein the clamp comprises a first portion and a second portion, where the first portion and the second portion are movable to allow engagement with the expansion control member.

42. The catheter of any of claims 37 to 41, wherein the expansion control member is further configured to adjust a stiffness of the expandable flexible framework, from a first stiffness to a second stiffness, and maintain the first stiffness or the second stiffness when theselective movement limiter couples with the expansion control member and limits a longitudinal movement of the expansion control member.

43. The catheter of claim 42, wherein: the expansion control member is configured to move freely when the selective movement limiter is not coupled with the expansion control member; and optionally wherein the selective movement limiter is configured as a clamp where the clamp engages the expansion control member and limits the longitudinal movement of the expansion control member.

44. The catheter of any of claims 37 to 43, wherein the flexible tip portion is configured to prevent longitudinal movement between the electrode-carrying arms and the distal end of the catheter shaft.

45. The catheter of any of claims 37 to 44, wherein a proximal coupler is mounted on or within the distal end of the catheter shaft, optionally wherein the proximal portion of each of the electrode-carrying arms extends through the proximal coupler and wherein each electrode-carrying arm exits from a distal end of the proximal coupler.

46. The catheter of any of claims 37 to 45, wherein the plurality of electrodecarrying arms are longitudinally-extending and laterally separated electrode-carrying arms, optionally extending parallel to the catheter shaft longitudinal axis.

47. The catheter of any of claims 37 to 46, wherein the plurality of electrodecarrying arms lie in a plane in the first non-expanded configuration.

48. The catheter of any of claims 37 to 47, wherein the expandable flexible framework comprises between four and 16 electrode-carrying arms, optionally 8 electrodecarrying arms.

49. The catheter of any of claims 37 to 48, wherein the plurality of electrodes are equally spaced along each of the plurality of electrode-carrying arms.

50. The catheter of any of claims 37 to 49, wherein at least some of the plurality of electrodes are ring, spot, or flexible electrodes.

51. The catheter of any of claims 37 to 50, wherein the electrodes are arranged on the electrode-carrying arms and configured for contacting tissue on a front side and a back side of the substantially planar array when in the first non-expanded configuration.

52. The catheter of any of claims 50 to 51, wherein the plurality of electrodecarrying arms comprises a first outboard arm, a second outboard arm, a first mid-board arm and a second mid-board arm, and four inboard arms, wherein the plurality of electrodes on the first mid-board arm, second mid-board arm, and four inboard arms are mounted on outward-facing surfaces of the electrode-carrying arms, optionally wherein the electrodes on the first and second outboard arms are ring, spot, or flexible electrodes.

53. The catheter of any of claims 37 to 52, wherein a separate electrical lead wire or conductive trace is electrically coupled to each electrode in the plurality of electrodes.

54. The catheter of any of claims 37 to 53, wherein the plurality of electrodes are arranged in a plurality of rows, wherein each row is distributed along a different one of the plurality of electrode-carrying arms and the plurality of rows is aligned parallel to the catheter shaft longitudinal axis.

55. The catheter of claim 54, wherein the plurality of electrode-carrying arms are 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.

56. The catheter of any of claims 37 to 55, wherein the electrodes are all the same size.

57. The catheter of any of claims 54 to 56, wherein four electrodes of the plurality of electrodes are placed and configured as localization and focal ablation electrodes, and wherein each of these four localization and focal ablation electrodes is placed among a different row of the plurality of rows of electrodes.

58. The catheter of any of claims 37 to 55, wherein the plurality of electrodecarrying arms comprises a first outboard arm, a second outboard arm, a first mid-board arm and a second mid-board arm, each having an electrode slightly longer than the other electrodes, optionally wherein each longer electrode is on a shoulder of the arm.

59. The catheter of any of claims 37 to 58, further comprising a distal coupler at the distal apex of the flexible tip portion.

60. The catheter of claim 59, wherein the distal coupler is configured to be electrically active, optionally wherein the distal coupler is a distal electrode.

61. The catheter of any of claims 37 to 60, wherein the plurality of electrodes are configured for use in unipolar, bipolar or omnipolar measurements or ablation.

62. The catheter of any of claims 37 to 61, further comprising at least one internal, longitudinally-extending fluid delivery lumen adapted to be fluidly coupled to a source of irrigant, wherein the catheter comprises at least one irrigation hole in fluid communication with the at least one fluid delivery lumen.

63. The catheter of claim 62, wherein the fluid delivery lumen is adapted to deliver the irrigant through the at least one irrigation hole on or adjacent to the electrodes.

64. The catheter of any of claims 37 to 62, further comprising at least one electrode mounted on or within the distal end of the catheter shaft adjacent to the flexible tip portion, optionally wherein the electrode is a ring, spot, or flexible electrode.

65. The catheter of any of claims 37 to 64 when dependent on claim 45, further comprising a proximal coupler cap, wherein a) the proximal coupler cap is configured to be electrically active, and / or b) the catheter further comprises at least one electrode mounted on the proximal coupler or proximal coupler cap.

66. The catheter of any of claims 37 to 65, further comprising at least one location sensor.

67. The catheter of claim 66, wherein the at least one location sensor is mounted in or on at least one of the following: the catheter shaft; or the distal end of the flexible tip portion.

68. The catheter of claim 66 or 67, wherein the at least one location sensor is a magnetic field sensor.

69. The catheter of any of claims 37 to 68, further comprising a temperature sensor.

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