Epicardial ablation and mapping catheter

Abstract

A catheter for mapping and ablating epicardial tissue, the catheter comprising: a shaft configured for insertion into a body of a subject; a distal assembly configured at a distal end of the shaft, the distal assembly being expandable from a collapsed state to a deployed state; the distal assembly comprises at least two frame elements; each frame element includes an arcuate distal portion on which is disposed a plurality of electrodes for delivering ablation energy; wherein in the deployed state, the distal assembly presents a concave profile for conforming to the curvature of the epicardium; and a plurality of position sensors disposed on one or both of the shaft and the frame element for tracking a position and orientation of at least a portion of the distal component or the shaft.

Description

Technical Field

[0001] The present invention relates to cardiac catheters, and in particular to catheters for mapping and / or ablating epicardial tissue. Background Art

[0002] US10966623B2 discloses: "A catheter suitable for high-density mapping and / or ablation of a tissue surface and having a distal electrode array with offset ridge rings, each ridge ring having at least a pair of linear portions and a distal portion connecting the pair of linear portions, and one or more electrodes located on each linear portion. The linear portions of the plurality of offset ridge rings are arranged within a plane of a single common plane, and the distal portions of the plurality of offset ridge rings are arranged outside the plane of the single common plane." BRIEF DESCRIPTION OF THE DRAWINGS

[0003] In order to better understand the subject matter disclosed herein and to illustrate how the same may be implemented in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0004] Figure 1 A catheter-based electrophysiological mapping and ablation system according to an example of the presently disclosed subject matter is illustrated;

[0005] Figure 2 is a flow chart of a general method for ablating and / or mapping epicardial tissue according to an example of the presently disclosed subject matter;

[0006] FIG. 3A to FIG. 3C is a schematic top view of a distal tip of a catheter for ablation and / or mapping of epicardial tissue according to an example of the presently disclosed subject matter ( Figure 3A , Figure 3C ) and a schematic side cross-sectional view ( Figure 3B );

[0007] Figure 4 is placed in contact with epicardial tissue according to an example of the presently disclosed subject matter FIG. 3A to FIG. 3B A schematic diagram of a portion of the distal tip of the catheter shown; and

[0008] Figure 5 is based on an example of the presently disclosed subject matter FIG. 3A to FIG. 3C A schematic cross-sectional view of the distal tip of a catheter is shown, illustrating the distal assembly in a collapsed state within the sheath of the catheter. DETAILED DESCRIPTION

[0009] In the following detailed description, many specific details are set forth in order to provide a comprehensive understanding of the present invention. However, it should be understood by those skilled in the art that the subject matter disclosed in the present invention can be practiced without these specific details. In other cases, well-known methods, procedures, components and circuits are not described in detail to avoid obscuring the subject matter disclosed in the present invention.

[0010] Unless otherwise specifically stated, it will be apparent from the following discussion that throughout the specification, discussions utilizing terms such as "processing," "computing," "comparing," etc. refer to the actions and / or processes of a computer that manipulates data and / or transforms data into other data, the data being represented as physical (such as electronic) quantities and / or the data representing physical objects. The term "computer" should be broadly interpreted to encompass any kind of hardware-based electronic device with data processing capabilities, including, as a non-limiting example, the manufacturing process inspection information (FPEI) system disclosed in this application and its corresponding parts.

[0011] The present disclosure relates to electrophysiological mapping and / or ablation of the epicardium of the heart performed using a catheter. One challenge involved with such procedures is how to effectively and efficiently ablate large tissue surface areas. Another challenge is how to enhance electrode-tissue contact, e.g., to ensure that ablative energy is transmitted to the tissue. Another challenge is how to engage tissue in naturally curved or rounded (e.g., convex) anatomical structures. Yet another challenge is how to introduce and position a catheter into the limited volume of the pericardial cavity, and how to perform treatment from within that cavity.

[0012] One or more of the above challenges may be overcome using a catheter device, for example as described herein:

[0013] According to a first aspect, a catheter includes a distal assembly on which a plurality of electrodes are mounted for ablation and / or position sensing, and the distal assembly is configured to present a concave profile (at least at a portion thereof) shaped to conform to a rounded tissue surface (e.g., a convex surface) of the epicardium. In use, the distal assembly (at its concave portion) scoops tissue, thereby potentially increasing the contact area between the electrodes and the tissue, for example, compared to a planar (flat) distal assembly.

[0014] According to a second aspect, one or more inflatable elements (e.g., balloons) can be positioned relative to the posterior side of the distal assembly (i.e., the side opposite the side that contacts the epicardial tissue). The inflatable elements can be effective for one or more of the following: for example, supporting and stabilizing the electrode against the epicardial tissue during ablation; providing insulation for the posterior side of the electrode; forming or reinforcing a depression of the distal assembly when the inflatable elements are pressed against the distal assembly when inflated within the limited volume of the pericardial cavity.

[0015] According to a third aspect, the distal assembly is maneuverable between a collapsed state in which the distal assembly fits compactly within the sheath of the catheter and an expanded, deployed state in which the distal assembly presents a concave (C-shaped) profile (at least at a portion thereof) for being placed in contact with tissue. In some examples, the distal assembly includes two or more annular frame elements that at least partially overlap each other, each of the frame elements defining a closed profile with the catheter shaft. In the collapsed state of the assembly, each of the frame elements is compressed (e.g., relative to its longitudinal axis) to facilitate receiving the distal assembly within the sheath; in the expanded, deployed state of the assembly, each of the frame elements expands laterally relative to its longitudinal axis, and the outer profiles of the two frame elements thereby together enclose a large tissue surface area.

[0016] In some examples, the electrodes are arranged on the frame element in a staggered manner. An advantage of the staggered electrode arrangement may be that the electrode-tissue contact area can be densely distributed, thereby providing increased coverage of the ablated tissue; another potential advantage of the staggered arrangement is that in the collapsed state of the distal assembly, the electrodes are adapted in an alternating manner, thereby enabling the distal assembly to fit within the small diameter of the sheath.

[0017] refer to Figure 1 , which shows an example catheter-based electrophysiological mapping and ablation system 10. The system 10 includes at least one catheter that is inserted into the heart 12 by a physician 24. Typically, a delivery sheath is inserted in an intrathoracic approach and optionally guided to a desired location in the heart 12 via the apex of the heart. The catheter can then be inserted into the delivery sheath catheter to reach the desired location in the heart 12. In some examples, the desired location is the epicardium 71, and the catheter is introduced through the pericardium 73 to reach the epicardium.

[0018] Illustrated herein are example catheters 14 configured for ablating tissue and / or for sensing cardiac electrical activity and / or mapping. A physician 24 may place a distal tip 28 of the catheter 14 in contact with an epicardial tissue surface for sensing and / or ablation.

[0019] The catheter 14 is an exemplary catheter that includes a distal assembly having one and preferably multiple electrodes 26, which are optionally distributed over multiple frame elements 22 at a distal tip 28. The electrodes are typically configured to deliver ablation energy to tissue and / or to sense cardiac electrical signals. The catheter 14 further includes one or more position sensors 29 embedded in or near the distal tip 28 for tracking the position and orientation of the distal tip 28. Optionally and preferably, the position sensor 29 is a magnetic-based position sensor, such as a position sensor including three magnetic coils for sensing three-dimensional (3D) position and orientation; or a position sensor including one magnetic coil for sensing a single direction.

[0020] Each of the magnetic-based position sensors 29 can operate with a positioning pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predetermined working space. The real-time position of the distal tip 28 of the catheter 14 can be tracked based on the magnetic field generated by the positioning pad 25 and sensed by the magnetic-based position sensor 29. Details of magnetic-based position sensing technology are described in U.S. Patents 5,5391,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, and 6,892,091.

[0021] The system 10 includes one or more electrode patches 38 positioned in contact with the skin of the patient 23 to establish a position reference for impedance-based tracking of the positioning pad 25 and the electrodes 26. For impedance-based tracking, current is directed toward the electrodes 26 and sensed at the electrode skin patches 38 so that the position of each electrode can be triangulated via the electrode patches 38. Details of impedance-based position tracking techniques are described in U.S. Patents 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182.

[0022] Recorder 11 records and displays electrograms 21 captured using body surface ECG electrodes 18 and optionally cardiac signals captured using electrodes 26 of catheter 14. Recorder 11 may include pacing capabilities for pacing the cardiac rhythm and / or may be electrically connected to a separate pacemaker.

[0023] The system 10 may include an ablation energy generator 50 adapted to conduct ablation energy to an electrode 26 of a distal assembly at a distal tip of the catheter. The energy generated by the ablation energy generator 50 may include, but is not limited to, radio frequency (RF) energy or pulsed field ablation (PFA) energy (including monopolar or bipolar high voltage DC pulses that may be used to achieve irreversible electroporation (IRE)), or a combination thereof.

[0024] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between at least one catheter and other catheters, other electrophysiology equipment, a power source, and a workstation 55 for controlling the operation of the system 10. The electrophysiology equipment of the system 10 may include, for example, multiple catheters, a positioning pad 25, surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 additionally includes processing capabilities for enabling real-time calculation of the position of the catheter and for performing ECG calculations.

[0025] The workstation 55 includes a memory, a processor unit having a memory or storage device storing appropriate operating software, and a user interface capability. The workstation 55 can provide multiple functions, optionally including: (1) three-dimensional (3D) modeling of the endocardial anatomy and rendering the model or anatomical map 20 for display on the display device 27; (2) displaying the activation sequence (or other data) compiled from the recorded electrograms 21 on the display device 27 as representative visual markers or images superimposed on the rendered anatomical map 20; (3) displaying the real-time position and orientation of at least one catheter within the heart chamber; and (4) displaying a site of interest on the display device 27, such as where ablation energy has been applied. A commercial product embodying elements of the system 10 can be CARTO TM The 3 system was purchased from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618.

[0026] In some examples, an irrigation module 75 is provided for delivering an irrigation fluid, such as a saline solution, to the treatment site. The irrigation module may include a pump and an associated fluid tank.

[0027] Figure 2 is a flow chart of a general method for ablating and / or mapping epicardial tissue according to an example of the presently disclosed subject matter.

[0028] At 201, a catheter is introduced into the patient's body. In some cases, the catheter is introduced via a transthoracic approach. The catheter is then guided toward the heart under imaging guidance, and the distal tip of the catheter is advanced to the heart location intended for treatment. At 203, the distal tip is inserted through the pericardium (optionally, from the direction of the apex) and then positioned adjacent to epicardial tissue.

[0029] In some examples, optionally, a position sensor of the catheter (eg, a position sensor including a magnetic coil, such as described herein) is used to sense the position and / or orientation of the distal tip of the catheter or a portion thereof. Optionally, position coordinates are generated.

[0030] In some examples, mapping of surrounding tissue is performed based on data from position sensors, such as by acquiring data from multiple points. In some examples, data from position sensors is used to determine trajectory information from which motion characteristics such as contractility of the tissue can be inferred.

[0031] At 205, according to some examples, a distal assembly at the distal tip of the catheter is expanded. In some examples, during insertion of the catheter, the distal assembly is maintained in a collapsed state in which the assembly is contained within a sheath of the catheter; and when the distal tip is brought into proximity with a target location (e.g., an epicardial site), the assembly is expanded. In some examples, the distal assembly exhibits a spoon-like curvature when expanded, which is concave toward the tissue to be treated, as will be further described herein. In the expanded state, an electrode mounted on the distal assembly can be placed in contact with the tissue.

[0032] In some examples, an inflatable element (such as a balloon) is inflated to push the electrode against the tissue and stabilize the electrode in place. In some cases, the inflatable element is advanced from a catheter sheath and then filled with a fluid (e.g., saline) to apply pressure to the distal assembly from one side of the distal assembly. In some cases, the inflatable element is positioned in the pericardial cavity, between the distal assembly and the wall layer of the pericardium, so that the wall layer of the pericardium provides a reaction force acting on the inflatable element.

[0033] In some examples, cardiac electrical signals are sensed, for example, using one or more electrodes of a distal assembly. In some cases, the electrodes used to sense electrical signals are the same as ablation electrodes. Additionally or alternatively, separate electrodes dedicated to sensing electrical signals are used. In some examples, the location of the sensed signal is evaluated with the aid of one or more position sensors mounted on the catheter. Optionally, patterns of cardiac activity are determined, for example to identify arrhythmias (e.g., tachycardias, such as ventricular tachycardia) or other conditions and optionally their sources, for example to identify scarring on the epicardium associated with abnormal cardiac signals. In this way, locations intended for ablation can be carefully identified and selected.

[0034] At 207, according to some examples, ablative energy (e.g., higher power energy such as RF, PFA) is transmitted to the epicardial tissue via at least some of the electrodes of the distal assembly. Keeping the electrodes stable and in close contact with the tissue (such as with the aid of an inflatable element) can be advantageous in maximizing the contact surface area of ​​the electrodes with the tissue and potentially improving the delivery of ablative energy into the tissue.

[0035] In some cases, the distal assembly is steered to one or more additional target locations (optionally, epicardial target locations) to perform ablation. The target locations can be selected based on sensed and / or mapped cardiac electrical activity to block or modify arrhythmogenic electrical pathways.

[0036] In some examples, irrigation is performed. In some cases, irrigation is performed to cool tissue, for example, to reduce collateral damage to tissue adjacent to the target site. Irrigation can further cool the electrode (e.g., the energy emitting surface of the electrode), thereby potentially preventing overheating of the electrode. Various irrigation methods are described below.

[0037] It should be noted that position sensing of tissue or anatomical structures, cardiac electrical activity sensing, and / or mapping may be performed throughout a procedure or at any desired time during a procedure.

[0038] FIG. 3A to FIG. 3C is a schematic top view of a distal tip of a catheter for ablation and / or mapping of epicardial tissue according to an example of the presently disclosed subject matter ( Figure 3A , Figure 3C ) and a schematic side cross-sectional view ( Figure 3B ).

[0039] In some examples, the distal tip 301 of the catheter includes a distal assembly 303 extending from a distal end 305 of a shaft 307 .

[0040] The distal assembly can be configured between two states: a first state in which the assembly is collapsed so as to be contained within the sheath 309 of the catheter; and a second state (as shown herein) in which the assembly is expanded to protrude outwardly from the distal end of the sheath.

[0041] According to this example, the distal assembly includes at least two frame elements 311 (e.g., annular splines), each of which defines a closed profile with the distal end of the shaft. The two frame elements overlap each other at least partially. Each of the frame elements includes an arc-shaped distal portion, for example, a parabolic distal portion. In some examples, the frame element has a generally elongated annular shape, such as an oval, an elliptical, or as shown herein, with a flat base with rounded corners at its proximal portion, and a catenary arc shape (parabolic shape) extends distally from the flat base. It should be noted that although two frame elements are shown, other embodiments may include more than two frame elements (e.g., 3, 4, 5 frame elements) arranged in a partially overlapping manner.

[0042] A plurality of electrodes 315 are disposed on each of the frame elements along the arcuate distal portion of the element. The electrodes are spaced apart from one another. The electrodes may be configured for ablation and / or sensing. Optionally, all electrodes are configured for both ablation and sensing.

[0043] In some examples, at least some of the electrodes are configured for ablation, and at least some of the electrodes (optionally, of different types) are configured for sensing.

[0044] In some examples, the electrodes of the two frame elements are staggered.In the collapsed state of the distal assembly, the electrodes fit in an alternating manner, thereby enabling the distal assembly to fit within the small diameter of the sheath.

[0045] In some examples, multiple position sensors are disposed on the distal assembly and / or in or on the shaft. The position sensor may constitute one to three magnetic coils for sensing the position of at least a portion of the catheter (such as the distal assembly) along corresponding one to three axes. In some embodiments, a dual-axis position sensor or a three-axis position sensor (having two or three coils, respectively) is located in a device portion that is large enough to accommodate these sensors, such as inside the shaft; while in a device portion (such as the distal assembly) with limited volume or mounting surface, a single-axis position sensor is used. Optionally, the coil of the single-axis sensor is a printed coil.

[0046] In the example shown, a position sensor 329 constituting three magnetic coils for sensing position on three axes is disposed or embedded within the shaft; and a plurality of single-coil position sensors 331 (for sensing position along a single axis) are disposed on a frame element, optionally between adjacent electrodes, or optionally mounted on the electrodes themselves.

[0047] In some examples, the frame element is constructed of a shape memory material such as nitinol. Optionally, the frame is made of nitinol wire. Thus, when the distal assembly is advanced distally outward from the sheath (additionally or alternatively, the sheath is pulled proximally to allow release of the assembly), the assembly automatically springs back to its deployed state. The distal assembly is configured to assume its predetermined deployed state upon exiting the sheath, and remain in that configuration, thereby maintaining the following spatial relationships: the electrodes relative to each other; the electrodes relative to the position sensors; the position sensors relative to each other; the position sensors relative to the device portion, which may facilitate sensing and / or mapping. During use, the frame element may deform slightly under externally applied forces (such as forces acting on the device when pressed against tissue), and return to its original shape once the force is removed.

[0048] In some examples, during the transition from the collapsed state to the expanded state, each of the frame elements expands laterally relative to the long axis of the frame element (see long axis 319, 321, respectively). Figure 3B As shown, both frame elements are bent so that the distal assembly presents a concave (C-shaped) profile, which is configured to conform to the outer curved surface of the epicardium. In some examples, a depression is formed at the distal portion of the distal assembly, and the electrode is arranged at the distal portion. For example, as shown, the curvature starts from the horizontal axis 323 and continues to the distal end of the distal assembly. In some examples, the axis 323 is located at about 1 / 3, 1 / 4 of the length of the long axis of the frame element or in any case is located at less than 1 / 2, so that a depression is usually formed at the distal portion of the distal assembly, and the electrode is arranged at the distal portion.

[0049] In use, the distal assembly is positioned relative to the tissue so that the depression faces the epicardium. This enables the electrode to be placed in close contact with the tissue scooped by the distal assembly.

[0050] In some examples, the frame elements partially overlap each other. The longitudinal axes 319 and 321 of the two frame elements may be spaced apart from each other. For example, potential advantages of multiple frame elements that partially overlap each other may include a relatively large surface area covered by the distal assembly compared to a single frame element or an arrangement in which the frame elements completely overlap. Covering a large tissue surface area can provide improved treatment effects because more tissue is ablated at the same time; and can reduce the number of positions to which the catheter tip needs to be manipulated, thereby potentially facilitating and accelerating the procedure. In some examples, the wires of the two frame elements are staggered with each other at the overlapping portions.

[0051] In some examples, the catheter includes an inflatable element, such as a balloon 333 (a schematic representation of which is shown). The balloon is configured to be inflated with a fluid (such as saline) through the shaft or through a dedicated catheter (not shown). In some embodiments where an irrigation fluid is supplied through the catheter, the balloon can be inflated with the irrigation fluid.

[0052] The balloon is positioned relative to the distal assembly so that when inflated, the electrode of the distal assembly is pushed toward the tissue surface by the balloon. In some examples, the balloon is positioned and configured to serve as a rear support layer for the distal assembly. Optionally, the balloon contacts the surface of the electrode opposite to the energy emitting surface. Potential advantages of supporting the distal assembly by a balloon (or other suitable inflatable element) may include enhancing contact between the energy emitting surface of the electrode and the tissue, and stabilizing the electrode during sensing and / or ablation.

[0053] In some embodiments, the balloon is configured to be deployed from the distal end of the shaft together with the distal assembly. In some cases, the balloon is integral with the distal assembly and together they define a single deployable unit. Optionally, the balloon is mounted to the distal assembly at one or more portions thereof (e.g., at one or more locations of the surface of the balloon facing the electrode).

[0054] In some examples, the balloon includes one or more orifices 335 (see Figure 3C ), the one or more orifices allowing blood flow and / or irrigation flow into and / or out of the balloon. In some examples, the orifices define a non-inflatable lumen (e.g., a channel or slit) extending across the volume of the balloon. Additionally or alternatively, the orifices are in the form of small holes formed in the balloon material, sized to allow controlled leakage of fluid. The rate at which the fluid flows (e.g., slowly drips) through the holes is determined at least in part by the size of the holes. In some cases, the holes are positioned so that when the balloon is inflated, the holes are adjacent to the electrodes, and irrigation fluid supplied to the balloon can controllably leak through the holes to cool the electrodes, thereby potentially preventing overheating of the electrodes and / or overheating of adjacent non-target tissues.

[0055] In some examples, the balloon is formed as a unitary member; alternatively, the balloon includes a plurality of members (such as a plurality of elongated rib-like extensions) extending along at least a portion of the frame member on a side opposite to the side that contacts the tissue.

[0056] In some examples, the balloon is positioned and configured to create or enhance a concavity of the distal component, such as when inflated within the pericardial cavity, so that the balloon presses against the distal component, thereby causing it to conform to a rounded tissue surface. In this case, the distal component can be flat (planar) in its neutral state and at least partially deformed by the balloon when inflated.

[0057] Referring back to the electrodes, these electrodes are mounted on the frame element so that in the deployed, expanded state of the distal assembly, the energy emitting surfaces 316 (or generally, the tissue contacting surfaces) of the electrodes face in a similar direction, toward the center of the recess. Optionally and preferably, the energy emitting surfaces of the electrodes of both frame elements face in a similar direction.

[0058] In some examples, portions of the electrode other than the portion facing the center of the depression are covered with an insulating material that reduces or prevents the transmission of energy and / or heat. In addition to or in lieu of the insulating cover, an inflated balloon may be positioned at the rear side of the electrode or spline and electrically and / or thermally isolate the rear side of the electrode. Thus, the balloon may reduce or prevent unintended energy emission from the electrode in the direction of the pericardial sac.

[0059] Typically, the electrodes are annular, but other electrode shapes are contemplated (eg, flat electrodes, roller electrodes, hexagonal, or other shapes).

[0060] In some examples, the catheter includes one or more components for flushing. In some examples, the frame element may be formed with an irrigation outlet (e.g., a hole formed by perforation, drilling, laser cutting, etc.; not shown), and irrigation is supplied via the shaft, then passes through the frame element, and exits via the irrigation outlet. Additionally or alternatively, an irrigation outlet (not shown) is provided in the electrode, for example, by a hole extending through the electrode, and irrigation is supplied via the shaft, passes through the frame element, and exits via the irrigation outlet of the electrode. Additionally or alternatively, an irrigation tube and / or spray sleeve (not shown) is provided, for example, extending distally from the shaft or surrounding the shaft.

[0061] Figure 4 is placed in contact with epicardial tissue according to an example of the presently disclosed subject matter FIG. 3A to FIG. 3B A schematic diagram of a portion of the distal tip of a catheter is shown.

[0062] The schematic diagram shows a curved portion of the frame element 311 that is arcuate to fit around a generally curved surface 312 of the epicardium. Electrodes 315 are disposed along the curve, with their energy emitting surfaces 316 facing and contacting the epicardial surface. As can be observed, in this example, the curvature of the frame element is generally C-shaped.

[0063] In some examples, as shown, the balloon 333 is inflated on the posterior (convex) side of the frame element for applying pressure to the frame element and specifically to the electrode to ensure that the energy transmitting / receiving surface of the electrode is in close contact with the tissue. Optionally, the balloon is inflated to apply pressure to the electrode so that the electrode is slightly pressed against the tissue. In some examples, as shown, the balloon is inflated inside the pericardial cavity, between the epicardium and the wall layer of the pericardium. When the balloon is inflated in this confined space, the wall layer of the pericardium compresses the balloon and provides a reaction force that can help press the other side of the balloon against the electrode.

[0064] According to some examples, multiple orifices are further shown herein, such as channels 401 formed to extend throughout the entire balloon. The channels can remain free of inflation fluid and allow flushing fluid and / or blood to flow through. In some examples, the balloon includes individually inflatable cells separated from each other by channels. Alternatively, the balloon includes a single inflatable cell.

[0065] In some examples, the balloon is shaped similarly to the frame elements of the distal assembly, or at least similarly to their outermost contours, thereby lining the frame elements at their rear side.

[0066] In use, the electrode 315 is used to sense cardiac electrical activity from the surface of the epicardium, and / or to deliver ablation energy to the tissue. Energy can be applied between paired electrodes on the assembly in bipolar mode, or in monopolar mode, for example, between the electrodes and a separate common electrode. The common electrode can be configured in a back patch for placement on the patient's skin. Additionally or alternatively, the common electrode can be a reference electrode located on or in the catheter itself.

[0067] Figure 5 is based on an example of the presently disclosed subject matter FIG. 3A to FIG. 3B A schematic cross-sectional view of the distal tip of a catheter is shown, illustrating the distal assembly in a collapsed state within the sheath of the catheter.

[0068] In the example shown, the distal assembly 303 is in a collapsed state, wherein the distal assembly is configured to fit inside the lumen of the sheath 309. In the collapsed state, the maximum diameter 501 of the distal assembly is at least 5%, 10%, 15% shorter than the diameter 503 of the sheath. For example, the distal assembly is maintained in its collapsed state inside the sheath during introduction of the catheter into the body, during transfer of the catheter between treatment locations, and during removal of the catheter from the body.

[0069] In some examples, as shown, in the collapsed state, the frame elements 311 are maintained close together. The wireframe of each element is brought closer to the long axis of the element, and the electrodes 315 are staggered. In some examples, the collapsed state is obtained by pulling the distal assembly proximally (optionally, by pulling the shaft 307) to pull the distal assembly into the sheath; additionally or alternatively, the sheath is pushed distally to surround the distal assembly and compress it into its lumen.

[0070] In other examples, the frame elements of the distal assembly can be rolled or otherwise folded about the long axis of the shaft.

[0071] Embodiments of the present disclosure

[0072] Example 1

[0073] A catheter for mapping and ablating epicardial tissue, the catheter comprising:

[0074] a shaft configured for insertion into a body of a subject;

[0075] a distal assembly configured at a distal end of the shaft, the distal assembly being expandable from a collapsed state to an expanded state;

[0076] The distal assembly comprises at least two frame elements; each frame element comprises an arcuate distal portion on which a plurality of electrodes for delivering ablation energy are disposed; wherein, in the deployed state, the distal assembly presents a concave profile for conforming to the curvature of the epicardium; and

[0077] A plurality of position sensors are disposed on one or both of the shaft and the frame element for tracking the position and orientation of at least a portion of the distal assembly or the shaft.

[0078] Example 2

[0079] According to the catheter described in Example 1, the catheter also includes an inflatable element, which is capable of extending from the distal end of the shaft and is positioned to return the distal component when inflated and apply pressure to the distal component from a side opposite to the tissue contacting side of the distal component so as to push the multiple electrodes of the distal component against the tissue.

[0080] Example 3

[0081] A catheter according to Example 1 or Example 2, wherein each of the plurality of electrodes includes an energy emitting surface, the energy emitting surface being configured to contact tissue, and wherein the plurality of electrodes are disposed on the frame element so that the energy emitting surfaces of the plurality of electrodes are on a tissue contacting side of the distal component.

[0082] Example 4

[0083] A catheter according to Example 3, wherein the energy emitting surfaces of the plurality of electrodes face the center of the recess defined by the distal assembly.

[0084] Example 5

[0085] A catheter according to any one of embodiments 1 to 4, wherein the plurality of electrodes are staggered relative to each other such that in the collapsed state of the distal assembly, the electrodes are alternately adapted adjacent to each other.

[0086] Example 6

[0087]

[00146] The catheter of any one of Examples 1 to 5, wherein in the expanded state of the distal assembly, the at least two frame elements at least partially overlap.

[0088] Example 7

[0089]

[00136] The catheter of any one of Examples 1 to 6, wherein each of the frame elements defines a closed contour with the distal end of the shaft.

[0090] Example 8

[0091]

[00146] The catheter of any one of Examples 1-7, wherein each of the frame elements is comprised of a shape memory material.

[0092] Example 9

[0093] The catheter of any one of Examples 1 to 8, wherein the plurality of electrodes are configured to deliver radio frequency (RF) ablation energy or pulsed field ablation (PFA) energy.

[0094] Example 10

[0095] The catheter of any one of Examples 1 to 9, wherein the plurality of electrodes are configured for sensing cardiac electrical activity.

[0096] Embodiment 11

[0097] According to the catheter described in any one of Examples 1 to 11, the catheter also includes an outer sheath, and the axis and the distal component are accommodated in the outer sheath when in the collapsed state; and wherein the distal component is configured to expand from the collapsed state to the expanded state when protruding from the distal end of the sheath.

[0098] Example 12

[0099] A catheter according to any one of embodiments 1 to 11, wherein the plurality of position sensors include one or more of the following: a single-axis position sensor, a dual-axis position sensor, and a three-axis position sensor, the position sensors being capable of operating with a magnetic pad of a position sensing system.

[0100] Embodiment 13

[0101] Embodiment 1 The catheter of any one of Embodiments 1 to 12, wherein the inflatable element comprises a plurality of apertures to permit fluid flow therethrough.

[0102] Embodiment 14

[0103] Embodiment 14. The catheter of any one of embodiments 2 to 13, wherein the inflatable element comprises a single inflatable unit or a plurality of inflatable units.

[0104] Embodiment 15

[0105] A method of ablating epicardial tissue, the method comprising:

[0106] an introducing catheter comprising a distal assembly at a distal tip of the catheter, the distal assembly being configured to present a concave profile for conforming to the curvature of the epicardial tissue;

[0107] inflating an inflatable element on a rear side of the distal assembly; and

[0108] Ablation energy is delivered to the epicardial tissue via electrodes.

[0109] Example 16

[0110] Embodiment 15: The method of embodiment 15, wherein the inflatable element is inflated between the epicardium and the wall layer of the pericardium.

[0111] Embodiment 17

[0112] The method of Example 15 or Example 16, wherein the catheter further comprises a plurality of position sensors, and wherein the method comprises tracking the position and orientation of at least a portion of the catheter using the position sensors.

[0113] Embodiment 18

[0114] According to the method described in any one of Examples 15 to 17, the method also includes sensing cardiac electrical activity via electrodes of the distal component.

[0115] Embodiment 19

[0116] A method according to Example 18, the method comprising identifying an arrhythmia pattern associated with an epicardial source based on the sensed cardiac electrical activity.

[0117] Those skilled in the art will appreciate that, although the present invention has been described in terms of preferred embodiments, the concepts upon which this disclosure is based may be readily utilized as a basis for designing other structures, systems and processes for carrying out the several purposes of the present invention.

[0118] The various illustrative logic blocks, modules, and algorithmic steps described in conjunction with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, and steps have been generally described above with respect to their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. The described functionality may be implemented in different ways for specific applications, but such specific implementation decisions should not be interpreted as causing any departure from the scope of the present disclosure.

[0119] It will also be understood that the system according to the present disclosure can be implemented at least in part on a suitably programmed computer. Likewise, the present invention contemplates a computer program readable by a computer for performing the method of the present disclosure. The present disclosure also contemplates a non-transitory computer-readable memory tangibly embodying an instruction program executable by a computer for performing the method of the present disclosure.

[0120] Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

[0121] It should be noted that the words "comprising," "including," and "having" as used throughout the appended claims should be interpreted to mean "including but not limited to." Unless explicitly indicated to the contrary, the indefinite articles "a" and "an" as used herein in the specification and claims should be understood to mean "at least one." The phrase "and / or" as used herein in the specification and claims should be understood to mean "either or both" of the elements so combined, i.e., elements that are present in combination in some cases and separately in other cases.

[0122] It is important, therefore, that the scope of the present invention should not be interpreted as being limited by the illustrative embodiments set forth herein. Other variations are possible within the scope of the invention as defined by the appended claims. Other combinations and sub-combinations of features, functions, elements, and / or characteristics may be claimed by amendment of the present claims or by new claims in this or a related application. Such amendments or new claims, whether different, broader, narrower, or the same in scope as the original claims, whether directed to different combinations or to the same combination, are deemed to be included in the subject matter of this specification.

Claims

1. A catheter for mapping and ablating epicardial tissue, the catheter comprising: a shaft configured for insertion into a body of a subject; a distal assembly configured at a distal end of the shaft, the distal assembly being expandable from a collapsed state to an expanded state; The distal assembly comprises at least two frame elements; each frame element comprises an arcuate distal portion on which a plurality of electrodes for delivering ablative energy are disposed; wherein, in the deployed state, the distal assembly presents a concave profile for conforming to the curvature of the epicardium; and A plurality of position sensors are disposed on one or both of the shaft and the frame element for tracking the position and orientation of at least a portion of the distal assembly or the shaft.

2. The catheter according to claim 1 further includes an inflatable element which is capable of extending from the distal end of the shaft and is positioned when inflated to return the distal component and apply pressure to the distal component from a side opposite to the tissue contacting side of the distal component so as to push the multiple electrodes of the distal component against the tissue.

3. The catheter according to claim 1, wherein Each electrode of the plurality of electrodes includes an energy emitting surface configured to contact tissue, and wherein the plurality of electrodes are disposed on the frame element such that the energy emitting surfaces of the plurality of electrodes are on a tissue contacting side of the distal assembly.

4. The catheter according to claim 3, wherein: The energy emitting surfaces of the plurality of electrodes face toward a center of a recess defined by the distal assembly.

5. The catheter according to claim 1, wherein The plurality of electrodes are staggered relative to one another such that in the collapsed state of the distal assembly, the electrodes alternately fit adjacent one another.

6. The catheter according to claim 1, wherein In the deployed state of the distal assembly, the at least two frame elements at least partially overlap.

7. The catheter according to claim 1, wherein: Each of the frame elements defines a closed contour with the distal end of the shaft.

8. The catheter according to claim 1, wherein Each of the frame elements is composed of a shape memory material.

9. The catheter according to claim 1, wherein: The plurality of electrodes are configured to deliver radio frequency (RF) ablation energy or pulsed field ablation (PFA) energy.

10. The catheter according to claim 1, wherein The plurality of electrodes are configured to sense cardiac electrical activity.

11. The catheter of claim 1 , further comprising an outer sheath, wherein the shaft and the distal assembly are contained within the outer sheath when in the collapsed state; and wherein, The distal assembly is configured to expand from the collapsed state to the expanded state while protruding from the distal end of the sheath.

12. The catheter of claim 1, wherein: The plurality of position sensors include one or more of: a single axis position sensor, a dual axis position sensor, and a triple axis position sensor operable with a magnetic mat of a position sensing system.

13. The catheter according to claim 2, wherein: The inflatable element includes a plurality of orifices that allow fluid to flow therethrough.

14. The catheter according to claim 2, wherein: The inflatable element comprises a single inflatable unit or a plurality of inflatable units.

15. A method of ablating epicardial tissue, the method comprising: an introducing catheter comprising a distal assembly at a distal tip of the catheter, the distal assembly being configured to present a concave profile for conforming to the curvature of the epicardial tissue; inflating an inflatable element on a rear side of the distal assembly; as well as Ablation energy is delivered to the epicardial tissue via electrodes.

16. The method according to claim 15, wherein: The inflatable element is inflated between the wall layers of the epicardium and the pericardium.

17. The method according to claim 15, wherein: The catheter further comprises a plurality of position sensors, and wherein the method comprises tracking a position and orientation of at least a portion of the catheter using the position sensors.

18. The method of claim 15, further comprising sensing cardiac electrical activity via electrodes of the distal assembly.

19. The method of claim 18, comprising identifying an arrhythmia pattern associated with an epicardial source based on the sensed cardiac electrical activity.

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