Folded fan catheter with electrodes

Abstract

The invention is entitled "Folding Fan Catheter with Electrodes." An apparatus includes a shaft and a folding fan catheter. The shaft is configured for insertion through a sheath into a lumen of an organ of a patient. The folding fan catheter is secured to a distal end of the shaft and includes: (a) a resiliently foldable frame secured to the distal end of the shaft and configured to unfold so as to assume a fan shape; (b) one or more flexible surfaces coupled to the frame to form a fan surface when the frame is unfolded; and (c) a plurality of electrodes disposed on the one or more flexible surfaces and configured to contact tissue.

Description

Technical Field

[0001] This invention relates generally to medical probes, and more specifically to multi-electrode catheters. Background Technology

[0002] Patent documents disclose various medical probes with distal end geometries designed to treat specific tissues. For example, U.S. Patent 8,133,221 describes a method for treating anatomical tissue defects such as patent foramen ovale (PFO). This method typically involves positioning the distal end of an elongated catheter device at the site of the anatomical defect, exposing an expandable shell and an energy delivery member outside the distal end of the catheter device, engaging the shell with tissue at the site of the anatomical defect, applying suction to the tissue via the shell to bind the tissue together, and applying energy to the tissue using the energy delivery member to substantially acutely close the anatomical defect. The device typically includes an elongated catheter body, a shell extending from the distal end of the catheter body for engaging tissue at the site of the anatomical defect, and an energy delivery member adjacent to the distal end of the shell, the energy delivery member having at least one substantially planar surface.

[0003] For example, U.S. Patent 9,492,228 describes systems, methods, and apparatuses that allow endovascular or percutaneous mapping, orientation, and / or ablation within body cavities or lumens. The apparatus includes elongated members capable of moving between an undilated configuration and an expanded or fan-shaped configuration. In the undilated configuration, the elongated members form a stack to fit through the catheter sheath. As the elongated members are advanced from the sheath into a curved or coiled stack configuration, they follow a corresponding arcuate or curved path (using a vortex, coil, or p-shape) and can be nested. The elongated members are circumferentially fan-shaped or radially spaced relative to each other to form an expanded or fan-shaped configuration. Transducer elements carried by the elongated members sense various physiological properties of adjacent tissue and / or can apply energy to adjacent tissue. In the expanded configuration, the elongated members can rotate in groups or as a set. The apparatus is retractable.

[0004] U.S. Patent 5,904,711 describes a method and apparatus for thoracoscopic defibrillation of a patient's heart. The technique involves introducing a first electrode via percutaneous intercostal puncture, positioning the first electrode against the surface of the heart, and positioning a second electrode against the patient's body. A voltage is then applied to both the first and second electrodes via the percutaneous intercostal puncture to deliver electrical energy through at least a portion of the patient's heart to both the first and second electrodes. During cardiac procedures, such as those involving cardiac arrest, the electrical energy applies a charge to the patient's heart to defibrillate the myocardium or restore a heartbeat. Summary of the Invention

[0005] The embodiments of the invention described below provide a device including a shaft and a folded fan-shaped conduit. The shaft is configured for insertion through a sheath into a cavity of a patient's organ. The folded fan-shaped conduit is fixed to a distal end of the shaft and includes: (a) a resilient foldable frame fixed to the distal end of the shaft and configured to unfold to present a fan shape; (b) one or more flexible surfaces coupled to the frame to form a fan-shaped surface when the frame is unfolded; and (c) a plurality of electrodes disposed on the one or more flexible surfaces and configured to contact tissue.

[0006] In some embodiments, the flexible foldable frame is at least partially made of a shape memory alloy having a self-configurable pre-shaped shape, which, when unconstrained, includes either a folding fan shape or an unfolding fan shape.

[0007] In some implementations, the flexible, foldable frame includes multiple slats.

[0008] In one embodiment, the slats are strip-shaped and configured to stack when the frame is folded. In another embodiment, each strip is configured to bend about its longitudinal axis when the frame is unfolded, such that the strip lies in the plane of the fan-shaped surface when the frame is unfolded.

[0009] In one embodiment, the pre-formed shape of the frame includes the folding fan shape, and also includes a pull line attached to the distal end of the slat and configured to pull the frame open to form the unfolded fan shape when pulled. In another embodiment, the pre-formed shape of the frame includes the unfolded fan shape, and the frame is configured to collapse when pulled back into the sheath.

[0010] In some embodiments, the one or more flexible members include one or more flexible printed circuit boards (PCBs), and the electrode is formed in one or more conductive layers of the PCB.

[0011] According to another embodiment of the invention, a method is provided comprising inserting a folded fan-shaped conduit fixed to a distal end of a shaft through a sheath into a cavity of a patient's organ. The folded fan-shaped conduit includes: (a) a resilient, foldable frame fixed to the distal end of the shaft and configured to unfold to present a fan shape; (b) one or more flexible surfaces coupled to the frame to form a fan-shaped surface when the frame is unfolded; and (c) a plurality of electrodes disposed on the one or more flexible surfaces and configured to contact tissue. After the folded fan-shaped conduit exits the sheath within the cavity and the resilient inner end segment presents the fan shape, contact is formed between the plurality of electrodes and the tissue, and medical procedures are performed using the electrodes.

[0012] In some embodiments, inserting the conduit includes allowing the frame to self-expand if the preformed shape includes the unfolding fan shape.

[0013] According to another embodiment of the invention, a method for manufacturing a folded fan-shaped duct is also provided, the method comprising securing a resilient, foldable frame to a distal end of a shaft, the resilient, foldable frame being configured to unfold to present a fan shape. One or more flexible surfaces are coupled to the frame to form a fan-shaped surface when the frame is unfolded. A plurality of electrodes are disposed on the one or more flexible surfaces, wherein the electrodes are configured to contact tissue.

[0014] The invention will be more fully understood through the following detailed description of embodiments thereof, taken in conjunction with the accompanying drawings, wherein: Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a catheter-based irreversible electroporation (IRE) ablation system according to an embodiment of the present invention, which includes a flat array of multiple electrodes;

[0016] Figure 2A and Figure 2B The images schematically illustrate the folded and unfolded layouts according to embodiments of the present invention. Figure 1 Side view of the folded fan duct;

[0017] Figure 3A In order to be in the embodiment of the present invention Figure 2B Isometric view of the folded fan duct with folded layout;

[0018] Figure 3B An isometric view of the duct in its unfolded configuration;

[0019] Figure 3C A perspective view of orthogonal cross sections to show the parallel stepped arrangement of stacked frame members;

[0020] Figure 3D for Figure 3C Another cross-sectional view of the far side of the frame members, to show the cross-section of the twisted portion of each frame member;

[0021] Figure 3E for Figure 3D Another cross-sectional view of the far side of the frame member;

[0022] Figure 3F A cross-sectional plan view obtained by the observer along the longitudinal axis of the duct to show the details of the stepped parallel frame members; and

[0023] Figure 4 To illustrate the use of exemplary embodiments of the present invention Figure 2A and Figure 2B A flowchart of the irreversible electroporation (IRE) method for folded fan ducts. Detailed Implementation

[0024] Overview

[0025] Radiofrequency ablation (using AC signals) or irreversible electroporation (IRE), also known as pulsed field ablation (PFA) (using DC signals), can be used as an invasive treatment modality to kill tissue cells in a patient's organ by subjecting them to high-voltage pulses. Specifically, RF or PFA pulses have the potential application of killing myocardial tissue cells (e.g., myocardial tissue cells in the heart chambers) to treat heart conditions. Of particular interest is the use of bipolar electrical pulses (e.g., using a pair of electrodes in a catheter in contact with tissue) to kill tissue cells between the electrodes. Cell destruction occurs when the transmembrane potential exceeds a threshold, leading to cell death and thus the development of tissue lesions.

[0026] For RF or PFA to be effectively used to ablate selected tissue, it is important to be able to bring the electrode delivering the RF or PFA pulses into contact with the selected tissue. While this is possible with virtually any catheter (such as a lesion catheter or basket catheter), if a large area of ​​tissue needs to be ablated, these catheter types need to be moved between multiple locations to cover the desired area. Furthermore, the electrode must remain in contact with the surface tissue during cardiac wall movement, which specifically increases complexity and the time required to complete the ablation.

[0027] Using multiple electrodes positioned close to each other and in contact with the surface tissue can enhance the effectiveness of RF or PFA ablation by strengthening the applied electric field and optionally by locally controlling the direction of the electric field to achieve better selectivity.

[0028] The embodiments of the present invention described below provide a folded fan-shaped catheter that, when unfolded, has a planar fan shape that can accommodate various types of electrodes, such as large-area electrodes, to apply RF pulses or PFA pulses to the inner surface of a cavity in a patient's organ.

[0029] In some embodiments, the frame of the folded fan duct is formed of a flat strip (e.g., nitinol slats) that can be tilted at its pivot point, thereby allowing the planar fan to be easily bent, for example, in a direction orthogonal to the fan plane. If the frame has a pre-formed folded shape, the frame can be unfolded by a pull wire to separate the slats. Alternatively, the frame can be pre-formed into an unfolded shape and held folded (e.g., collapsed) within a sheath, presenting a fan shape through self-expansion, and collapsing by being drawn back into the sheath.

[0030] The flexible membrane is coupled (e.g., bonded) to a frame, and electrodes are arranged on the membrane. In one embodiment, the membrane includes a flexible printed circuit board (PCB) having electrodes formed thereon. In its expanded configuration, the slats of the frame hold the shape of the conduit in a fan plane, such that the inter-electrode spacing is fixed and stable. However, the conduit is flexible in a direction perpendicular to the fan plane, thus adaptable to the variable-shape surfaces of anatomical structures.

[0031] In some embodiments, where the preformed shape is a folding fan, pull wires are attached to the very ends of the two outer slats to pull them apart. The PCB serves as a connecting member between the slats, thus defining the geometry of the fully deployed folding fan duct as a flat-shaped surface. In some embodiments, the slats are rigidly coupled to the distal edge of the duct's axis and can be preferentially actuated due to the uneven force of the pull wires on each side. Over-deployment remains limited by the connecting material between the slats.

[0032] The fan-shaped architecture disclosed in this invention thus enables physicians to achieve high-quality contact between electrodes and tissues with variable geometries. The connecting membrane (e.g., a flexible PCB) may comprise a set of separate sections, each connected between two adjacent strips, which in some designs increases the flexibility of the catheter perpendicular to the fan plane.

[0033] In some implementations, impedance-based tracking systems and / or magnetic field-based tracking systems are used to navigate the catheter to the desired area of ​​the tissue. Once in place, the physician uses the provided RF or PFA ablation protocol to select which electrodes will be used for RF or PFA ablation, as well as the IRE pulse parameters.

[0034] In one implementation, a physician inserts a collapsed folded fan, housed within a sheath, into the heart chamber and subsequently expands the fan to contact the inner surface of the chamber. The physician specifies one or more tissue segments to be ablated on the inner surface. In response to this input, a processor selects one or more electrode pairs disposed on a connecting membrane (e.g., a flexible PCB) that ablate the specified tissue segments when driven by an RF or PFA signal. An RF or PFA pulse generator, controlled by the processor, ablates the specified segments by applying the RF or PFA signal to the electrode pairs.

[0035] In one implementation, the physician, for example, uses a method based on measuring the frequency response of the electrodes (as described in commonly assigned U.S. Patent Application Publication 2019 / 0365463, which is incorporated herein by reference and a copy is provided in the appendix) to receive an indication of which electrodes of the catheter's electrode array are in contact with the tissue, and then selects at least those electrodes of the array as described below.

[0036] By using a folded fan-shaped catheter, the invasive cardiac diagnostic and therapeutic techniques disclosed in this invention can produce effective and consistent RF or PFA ablation over large areas and in complex tissue anatomy.

[0037] System Description

[0038] Figure 1 This is a schematic diagram of a catheter-based ablation system 20 including a folded fan catheter 50 according to an embodiment of the present invention.

[0039] System 20 is used to determine the position of the folded fan catheter 50, shown in illustration 25, mounted at the distal end of shaft 22, to ablate target cardiac tissue of the heart 26 of patient 28 using RF or PFA.

[0040] The physician 30 navigates the folded-fan catheter 50 to the target tissue location in the heart 26 by manipulating the shaft 22 and / or deflecting it from the sheath 23 using a manipulator 32 located near the proximal end of the shaft. The folded-fan catheter 50 is inserted through the sheath 23 in a folded (i.e., collapsed) configuration, and only after the sheath 23 retracts does the folded-fan catheter 50 return to its intended functional shape, for example, by self-expanding into a pre-formed unfolded shape. By including the folded-fan catheter 50 in a folded configuration, the sheath 23 also serves to minimize vascular trauma along the route to the target location.

[0041] Typically, the folded fan catheter 50 is used for diagnostic or therapeutic procedures, such as spatial mapping of the heart and mapping of corresponding potentials in the heart prior to performing ablation of cardiac tissue.

[0042] As described above, the folded fan catheter 50 includes multiple electrodes (see Figure 2) disposed over a large area, which serve multiple purposes (i.e., navigation, sensing, and ablation). The electrodes are connected to an RF or PFA pulse generator 37 via wires (not shown) extending through shaft 22. This pulse generator includes a processor-controlled switching circuit 38 (e.g., a relay array) in console 24. Using circuit 38, the system processor or physician can select which electrodes are connected to the pulse generator 37 to apply RF or PFA pulses.

[0043] The console 24 includes a processor 41 (typically a general-purpose computer) with suitable front-end and interface circuitry 44 for receiving signals from the patch electrode 49. The signals from the electrode 49 may be electrocardiogram (ECG) and / or position signals used in the Advanced Catheter Position (ACL) location tracking method described below. The processor 41 is connected to the patch electrode 49 via a wire extending through a cable 39, which is attached to the skin of the patient 26's torso.

[0044] In some implementations, processor 41 precisely determines the position coordinates of the electrodes of the folded fan catheter 50 within the heart 26. Processor 41 determines the position coordinates based on measured impedance between the electrodes (on the catheter) and the ACL patch electrode 49 (i.e., using the ACL method described below) from other inputs. Console 24 drives display 27, which displays the distal end of the catheter's position within the heart.

[0045] When calculating the estimated location of at least a portion of the electrodes of the folded fan catheter 50 within the patient's heart, the processor 41 can then associate any given signal received from the electrodes (such as an electrophysiological signal) with the location where the signal was acquired.

[0046] The ACL method using electrode position sensing of System 20 has been implemented in various medical applications, such as CARTO manufactured by Biosense Webster (Irvine, California). TM The system is implemented and is described in detail in U.S. Patents 7,756,576, 7,869,865 and 7,848,787, the disclosures of which are incorporated herein by reference in their entirety.

[0047] The console 24 also includes a magnetic induction subsystem. The patient 28 is placed in a magnetic field generated by a pad housing a magnetic field generator coil 42, which is driven by unit 43. The magnetic field generated by coil 42 generates a position signal in a magnetic sensor 46 (shown in illustration 25), which is mounted only proximally to the folded fan catheter 50. The signal is also provided as a corresponding electrical input to a processor 41, which uses it to calculate, for example, the roll angle of the flat array 50 to correct for the electrode position and / or orientation derived from the ACL of the flat array within the lumen.

[0048] Position sensing methods using external magnetic fields have been implemented in various medical applications, such as the CARTO system manufactured by Biosense Webster Inc. (Irvine, California). TM The system is implemented and described in detail in U.S. Patents 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612, and 6,332,089, as well as PCT Patent Publication WO 96 / 05768, and U.S. Patent Application Publications 2002 / 0065455 A1, 2003 / 0120150 A1, and 2004 / 0068178 A1, the disclosures of which are all incorporated herein by reference.

[0049] Processor 41 is typically programmed in software to perform the functions described herein. This software can be downloaded to a computer electronically via a network, or alternatively, it can be set and / or stored on a non-transitory tangible medium (such as magnetic storage, optical storage, or electronic storage). Specifically, processor 41 operates to enable processor 41 to perform… Figure 3A The dedicated algorithm for the steps shown.

[0050] For the sake of simplicity and clarity, Figure 1 Only elements relevant to the technology disclosed in this invention are shown. System 20 typically includes additional modules and elements that are not directly related to the technology disclosed in this invention and are therefore intentionally omitted from view. Figure 1 And the corresponding description is omitted. Another position tracking technique similar to the ACL described above, which can be used to track the position of electrodes on the flat array 50 within the heart 26, is described in U.S. Patent Application 15 / 966,514 (now U.S. Patent Application Publication US20190328274), filed April 30, 2018, entitled "Improved Active Voltage Location (AVL) Resolution," which is assigned to the assignee of this patent application, and a copy thereof is provided in the appendix.

[0051] As used herein, the term “about” or “approximately” for any numerical or numerical range indicates that a portion or assembly of multiple parts is permitted to perform suitable dimensional tolerances for their intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of ±10% of the enumerated value, for example, “about 90%” may refer to a range of 81% to 99% of the value. The terms “far side” and “proximal side” are relative terms with respect to the operator of the device, such that “far side” indicates an area or portion of the device further away from the operator, and “proximal side” indicates an area or portion of the device closer to the operator than the far side area.

[0052] Folded fan duct with electrode array

[0053] Figure 2A and Figure 2B These are respectively, according to embodiments of the present invention, in folded and unfolded layouts. Figure 1 Side view of the folded fan duct 50.

[0054] In the illustrated embodiment, the resilient frame member 52 of the catheter is in Figure 2A The middle collapsed and in Figure 2B It expands in the form of a planar surface. For this purpose, the elastic frame member 52 bends at its base by approximately 90°, as... Figure 3E As shown. In Figure 2B In the second or unconstrained configuration, it should be noted that each frame member 52 is spaced from its adjacent adjacent frame member by an angle β of approximately 5 to approximately 15 degrees, as measured at the intersection of the frame members near axis 22. A preferred embodiment employs approximately 10 degrees. In this configuration, the frame members extend along their axis AA at a corresponding angle relative to the longitudinal axis LL, thereby defining a substantially planar triangular array of five finger-shaped frame members 52, with the membrane 53 disposed between the finger-shaped frame members 52. At least one of electrodes 54 and 56 may be disposed on the membrane 53. Electrode 54 or 56 may be formed of flexible circuit electrodes. Electrical traces may be used to connect the electrodes back to the proximal shank, or electrical traces may be connected to a frame member that can act as a conductor if the frame member is made of a biocompatible metal. Alternatively, wires may be used instead of PCB traces.

[0055] As further shown, the conduit 50 includes pull wires 55, each pull wire being attached to the very end 57 of the outer slats to pull the two outer ridges apart in the case of a self-configurable pre-formed shape as a folding fan.

[0056] The flexible PCB 53 is connected to the ridge 52 and serves as a connecting member between the various slats, thereby determining the complete deployment (60) of the folding fan duct, as shown here. Figure 3BAs shown. In other embodiments, over-deployment is limited by the connecting material between the selected strips, other than PCB 53 (e.g., a film).

[0057] Furthermore, in this embodiment, the slats are rigidly attached to the end position 62 of the shaft 22, which can preferentially bend due to the force of the traction wire on each side. Thus, the fan structure enables the deployable plane to achieve optimal contact in tissues with variable geometry, and the deployable plane can be actuated (70) by a physician to move outside the fan plane.

[0058] like Figure 3B As shown, the flexible PCB 53 is provided with a large-area electrode 54, the primary purpose of which is ablation, such as radiofrequency ablation or irreversible electroporation using PFA. Additionally, a smaller electrode 56 is primarily used for EP sensing (i.e., recording electrical signals from cardiac tissue). However, any electrode can be used for diagnosis or treatment, depending on, for example, the user's choice.

[0059] In its Figure 3B In the expanded configuration, flat frame ridges (e.g., bands) hold the conduit shape in the fan plane, making the inter-electrode spacing fixed and stable. However, the conduit is flexible in the direction perpendicular to the fan plane.

[0060] For the sake of simplicity and clarity, Figure 2A and Figure 2B Only elements relevant to the technology disclosed in this invention are shown. The folding fan duct 50 may also be provided with, for example, a temperature sensor and / or a contact force sensor.

[0061] Therefore, processor 41 can be used to select any electrode pair of electrodes 54 and 56, and subsequently command switching component 38 to connect the electrodes to RF or PFA pulse generator 37 to apply bipolar RF or PFA pulses, for example, between pairs of electrodes 54, and individually between pairs of electrodes 56. Alternatively, the processor can select electrode pairs 54-56 of the same component to switch to orthogonal directions of the electric field.

[0062] When used for IRE ablation, processor 41 is used to select an IRE ablation protocol that includes bipolar IRE pulses. Examples of IRE ablation settings that can be used with electrodes 54 and 56 are given in Table I:

[0063] Preset IRE peak voltage 500V to 3000V Pulse width 0.5 microseconds - 10 microseconds Repetition rate 1Hz-400Hz Number of pulses 10-2000 Direction of electric field User selection

[0064] Table I

[0065] As shown in Table I, the direction of the applied electric field is selected by the user.

[0066] Figure 3A In order to be in the embodiment of the present invention Figure 2B An isometric view of the unfolded layout of the folding fan duct.

[0067] like Figure 3A As shown, each of the strip frame members 521, 522, 523, 524, and 525 is configured to bend or twist (66) about the longitudinal axis AA of the slats when the frames 521-525 are in a constrained or folded configuration. Due to the twisting of the frame members 521-525, a biasing force is generated when the frame members 521-525 collapse or are constrained in the sleeve 23. When the frames 521-525 are unfolded or unconstrained by the sleeve 23, such that when the frames are unfolded, the strips lie in the plane of the fan-shaped surface, as shown here. Figure 3B As shown. Therefore, the frame formed by the flat nitinol strip 52 with a 90° rotation (66) at its pivot point can be easily controlled by the pull wire (shown in Figure 2), allowing the frame (if pre-formed into a collapsed shape) to expand into the desired planar surface. Figure 3A In the first configuration, each of the multiple frame members 521, 522, 523, 524, and 525 has a planar surface "P1" (the lower surface of 50e) extending from the proximal portion 50e of the distal end 22a attached to the shaft 22 to the end portion (indicated by "P2"), with the planar surface at the end portion set at approximately 90 degrees relative to the planar surface at the proximal portion. It should be noted that surface P1 may be either the top or bottom surface of each frame member 52. For example, frame member 50a has a visible top surface P1 that is twisted along the length of frame member 521 to obtain a planar surface P2 at approximately 90 degrees relative to P1. That is, each of the frame members 521, 522, 523, 524, and 525 has three distinct portions. Taking frame member 521 as an example, it should be noted that frame member 521 has (a) a first fixed proximal planar portion 50a, (b) a second twisted intermediate portion 510, and (c) a final planar portion 52a. These portions contribute to the ability of the distal component to unfold into a generally planar triangular configuration.

[0068] Figure 3A The illustrated deployment layout is given by way of example only. For example, other methods can be used to form the deployment fan duct disclosed in this invention, such as using one or more rotation axes to connect frame members 521-525 to the distal end of shaft 22.

[0069] When frame members 512-525 are along Figure 3C , Figure 3D and Figure 3EWhen the length of a frame member is orthogonally cross-sectioned, certain characteristics of the frame member are noteworthy. Figure 3C As can be seen from the diagram, the fixed proximal fixing portions 50a, 50b, 50c, 50d, and 50e are planar components, and these planar components are... Figure 3F The stacked stepped configuration shown is parallel to each other. Figure 3F For the observer along Figure 3C The end view of the frame member observed along the longitudinal axis AA (where axis 22 is visible). Orthogonal cross-sections located on the distal side. Figure 3D From the data, it can be seen that cross sections 510, 511, 512, 513, and 514 are relative to... Figure 3C The corresponding cross sections 50a, 50b, 50c, 50d, and 50e are bent or twisted. Each frame member in frame members 521-525 is twisted until the cross section of the frame member presents a specific shape. Figure 3E The final configuration is shown in the orthogonal cross-sectional view. Frame members 521-525 will then have cross-sections indexed as 52a, 52b, 52c, 52d, and 52e. It is noteworthy that the final distal cross-sections 52a-52e are substantially perpendicular to the proximal cross-sections 50a-50e. Although the cross-section of each frame member is shown as generally rectangular, it is entirely within the scope of the invention that the cross-section may have any suitable cross-section (e.g., square, circular, polygonal), provided that (a) the cross-sections can be arranged in a stepped configuration of parallel stacks (…). Figure 3E (a) and (b) the frame members do not bond or interfere with each other in an unconstrained or uncompressed open configuration. The frame members are made of suitable biocompatible materials such as biocompatible metals or shape memory materials such as nitinol.

[0070] Figure 4 To illustrate the use of exemplary embodiments of the present invention Figure 2B A flowchart of an irreversible electroporation (IRE) method using a folded fan-shaped catheter 50. According to the presented embodiment, the algorithm execution process begins at the flat array navigation step 102, where the physician 30 uses, for example, sensors 46 to navigate the flat array 50 to a target tissue location in the patient's organ, such as the interatrial septum.

[0071] Next, at catheter 50 deployment step 104, physician 30 deploys planar array 50. Subsequently, at tissue contact step 106, physician 30 brings the sector with electrodes into contact with the tissue.

[0072] At the electrode physical contact determination and selection step 108, the processor 41 determines which of the electrodes 54 / 56 are in contact with the tissue, and the physician 30 selects at least a portion of these electrodes to apply an IRE pulse.

[0073] Next, at electrode configuration setting step 110, processor 41 receives user input, such as the user input in step 108, and / or in the form of one or more pre-specified directions (e.g., longitudinal axis relative to the distal end), along which an electric field should be applied to the tissue. Based on the desired electric field direction, processor 41 determines which electrode pairs of the selected electrodes 54 / 56 should be applied with, for example, RF or IRE pulses.

[0074] Next, at electrode pair connection step 112, processor 41 controls switching component 38 to connect electrode pair to IRE pulse generator 37 according to the determined configuration.

[0075] Then, at the RF or IRE parameter selection step 114, processor 41 receives (e.g., uploaded from memory) an ablation protocol including RF or IRE ablation parameters (e.g., the number of pulses and peak voltage). At this stage, the physician can modify some parameters. Alternatively, the protocol may have been loaded earlier in the procedure and is ready at this stage.

[0076] Finally, at RF or IRE processing step 116, processor 41 commands RF or IRE pulse generator 37 to apply directional RF or IRE pulses to the tissue via selected paired electrodes 55.

[0077] Figure 4 This is an exemplary flowchart, described merely for clarity. Additional steps may be included, such as, in the absence of sufficient information about cardiomyocyte orientation, the processor 41 controlling the switching component 38 to apply RF or PFA pulses to the same tissue region in multiple (typically two) different orientations. For example, the processor 41 may control the switching component 38 to apply RF or PFA pulses in two orthogonal directions.

[0078] While the implementation methods described herein primarily relate to cardiac applications, the methods and systems described herein can also be used in other medical applications, such as neurology and otolaryngology.

[0079] Therefore, it should be understood that the above embodiments are cited by way of example, and the invention is not limited to what has been specifically shown and described above. Rather, the scope of the invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which will occur to those skilled in the art upon reading the above description and which are not disclosed in the prior art. Documents incorporated herein by reference are considered an integral part of this application, except that if any terminology defined in such incorporated documents conflicts with the definitions expressly or implicitly given in this specification, only the definitions in this specification shall be considered.

Claims

1. An apparatus comprising: A shaft configured to pass through a sheath and be inserted into the cavity of a patient's organ; and A folding fan-shaped conduit, the folding fan-shaped conduit being fixed to the distal end of the shaft, the folding fan-shaped conduit comprising: A flexible foldable frame, fixed to the distal end of the shaft and configured to unfold to present a fan shape, wherein the flexible foldable frame includes a plurality of slats, each of the plurality of slats being generally flat and including a proximal planar portion, a distal planar portion and a twisted portion disposed therebetween; One or more flexible surfaces, said flexible surfaces being coupled to the frame to form a fan-shaped surface when the frame is deployed; and Multiple electrodes are disposed on one or more flexible surfaces and configured to contact tissue.

2. The device of claim 1, wherein the resilient foldable frame is at least partially made of a shape memory alloy having a self-configurable pre-formed shape, the self-configurable pre-formed shape comprising, when unconstrained, a folding fan shape and an unfolding fan shape.

3. The device of claim 1, wherein the slats are strip-shaped and configured to stack when the frame is folded.

4. The device of claim 3, wherein each strip is configured to bend about the longitudinal axis of the strip when the frame is deployed, such that when the frame is deployed, the strip lies in the plane of the sector surface.

5. The device of claim 2, wherein the pre-formed shape of the frame includes the folding fan shape, and includes a pull line attached to the distal end of the slat and configured to pull the frame open when pulled to form the unfolded fan shape.

6. The device of claim 2, wherein the preformed shape of the frame includes the unfolded fan shape, and wherein the frame is configured to collapse when drawn back into the sheath.

7. The device of claim 1, wherein one or more flexible members comprise one or more flexible printed circuit boards (PCBs), and wherein the electrodes are formed in one or more conductive layers of the PCB.

8. A method for manufacturing a folding fan duct, the method comprising: A flexible, foldable frame is fixed to the distal end of the shaft. The flexible, foldable frame is configured to unfold to present a fan shape. The flexible, foldable frame includes a plurality of slats, each of which is generally flat and includes a proximal planar portion, a distal planar portion, and a twisted portion disposed therebetween. One or more flexible surfaces are attached to the frame to form a fan-shaped surface when the frame is deployed; as well as Multiple electrodes are disposed on one or more flexible surfaces, wherein the electrodes are configured to contact tissue.

9. The method of claim 8, wherein the resilient foldable frame is at least partially made of a shape memory alloy having a self-configurable pre-formed shape, the self-configurable pre-formed shape comprising, when unconstrained, a folding fan shape and an unfolding fan shape.

10. The method of claim 8, wherein the slats are strip-shaped and configured to be stacked when the frame is folded.

11. The method of claim 10, wherein each strip is configured to bend about the longitudinal axis of the strip when the frame is deployed, such that when the frame is deployed, the strip lies in the plane of the sector surface.

12. The method of claim 9, wherein the pre-formed shape of the frame includes the folding fan shape, and includes attaching a pull line to the distal end of the slat, wherein the line is configured to pull the frame open when pulled to form the unfolded fan shape.

13. The method of claim 9, wherein the preformed shape of the frame includes the unfolded fan shape, and wherein the frame is configured to collapse when drawn back into the sheath.

14. The method of claim 8, wherein one or more flexible members comprise one or more flexible printed circuit boards (PCBs), and wherein the electrode is disposed of by forming the electrode in one or more conductive layers of the PCB.

15. A distal catheter tip assembly, comprising: A shaft extending along a longitudinal axis from a proximal portion to a distal end; A plurality of frame members are fixed to the distal end and extend along the longitudinal axis. The plurality of frame members have a first configuration in which the frame members are parallel to each other and a second configuration in which the frame members extend at corresponding angles relative to the longitudinal axis LL to define a substantially planar array of triangles. Each of the plurality of frame members is generally flat and includes a proximal planar portion, a distal planar portion and a twisted portion disposed therebetween. A membrane, wherein the membrane is disposed between any two frame members; and At least one electrode is disposed on the membrane.

16. The distal catheter end assembly of claim 15, wherein each of the plurality of frame members in the first configuration includes a planar surface extending from a proximal portion of the distal end attached to the shaft to a distal portion, the planar surface at the distal portion being configured at approximately 90 degrees relative to the planar surface at the proximal portion.

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