Medical probe with ridges for pulmonary vein isolation

Abstract

The disclosed technology includes a distal tip of a medical probe. The distal tip includes a neck and a ridge extending along a longitudinal axis. A neck extends from a proximal end of the distal tip. A ridge is connected to the neck and extends from an intermediate portion of the distal tip to a distal end portion of the distal tip. The ridge is movable between a collapsed configuration and an expanded configuration. In the collapsed configuration, the ridges extend along the longitudinal axis. In the expanded configuration, each ridge includes a curved portion curved away from the longitudinal axis and a planar portion extending from the curved portion to the distal end. Further, in the expanded configuration, each planar portion extends along a plane substantially orthogonal to the longitudinal axis.

Description

Technical Field

[0001] The present technology generally relates to medical devices, and more particularly to medical probes having electrodes, and further but not exclusively to medical probes suitable for mapping and / or ablating tissue. Background Art

[0002] When an area of cardiac tissue abnormally conducts electrical signals to adjacent tissue, arrhythmias such as atrial fibrillation (AF) can occur. This disrupts the normal cardiac cycle and results in an irregular heartbeat. Certain procedures are used to treat arrhythmias, including surgically disrupting the source of the arrhythmia signal and disrupting the conduction pathways for such signals. By selectively ablating cardiac tissue by applying energy via a catheter, it may sometimes be possible to stop or alter the propagation of unwanted electrical signals from one part of the heart to another.

[0003] Many current ablation methods in the art utilize radiofrequency (RF) electrical energy to heat tissue. RF ablation can have certain risks associated with thermal heating that can lead to tissue carbonization, burns, steam pops, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulas.

[0004] Cryoablation is an alternative to RF ablation that generally reduces the thermal risks associated with RF ablation. However, compared to RF ablation, it is generally more challenging to manipulate cryoablation devices and selectively apply cryoablation; thus, cryoablation is not feasible in certain anatomical geometries that can be reached by electroablation devices.

[0005] Some ablation methods use irreversible electroporation (IRE) to ablate cardiac tissue using a non-thermal ablation method. IRE delivers short pulses of high voltage to tissue and creates non-recoverable cell membrane permeabilization. Examples of systems and devices configured for IRE ablation are disclosed in U.S. Patent Publications Nos. 2021 / 0169550A1, 2021 / 0169567A1, 2021 / 0169568A1, 2021 / 0161592A1, 2021 / 0196372A1, 2021 / 0177503A1, and 2021 / 0186604A1, each of which is incorporated herein by reference.

[0006] In current practice, the effectiveness of IRE energy delivery depends on the skill of the physician, which means that patients may suffer from incomplete isolation of target areas such as the pulmonary veins. To effectively deliver IRE energy to perform pulmonary vein isolation (PVI), ablation catheters typically need to be reoriented multiple times during the procedure, which increases the procedure time and complicates the ablation process. Therefore, there is a need for an improved end effector for a medical probe that addresses these issues. Summary of the Invention

[0007] According to the disclosed technology, a distal end of a medical probe is provided. The distal end includes a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along a longitudinal axis. The ridge frame includes a neck and a plurality of ridges. The neck extends from the proximal end. The ridges are connected to the neck and extend along the intermediate portion to the distal end. The ridges are movable between (1) a collapsed configuration and (2) an expanded configuration, in which the ridges extend along the longitudinal axis in the collapsed configuration, and in which each ridge includes a bent portion that curves away from the longitudinal axis and a planar portion that extends from the bent portion to the distal end, and each planar portion extends in a plane that is generally orthogonal to the longitudinal axis.

[0008] According to the disclosed technology, a distal end of a medical probe is further provided. The distal end includes a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along a longitudinal axis. The ridge frame includes a neck, a plurality of ridges, and a crown. The neck extends from the proximal end. The ridges extend along the intermediate portion. Each ridge includes (1) a first straight portion connected to the neck and (2) a second straight portion including a first end and a second end. The first straight portion is connected to the second straight portion at a joint intermediate the first end and the second end. The crown is connected to the second straight portion and extends to the distal end. The ridge frame is movable between (1) a collapsed configuration and (2) an expanded configuration, in which each connected first straight portion and second straight portion are oriented at a first angle relative to each other in the collapsed configuration, and in which each connected first straight portion and second straight portion are oriented at a second angle relative to each other in the expanded configuration, the second angle being less than the first angle.

[0009] According to the disclosed technology, a system is further provided, the system including a medical probe, a guide wire, and a guiding sheath. The medical probe includes an elongate shaft and a distal end. The elongate shaft extends along a longitudinal axis. The distal end includes a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along a longitudinal axis. The ridge frame includes a neck and a plurality of ridges. The neck extends from the proximal end. The ridges are connected to the neck and extend along the intermediate portion to the distal end. The ridges are movable between (1) a collapsed configuration and (2) an expanded configuration, in which the ridges extend along the longitudinal axis in the collapsed configuration, and in which each ridge includes a bent portion that curves away from the longitudinal axis and a planar portion that extends from the bent portion to the distal end, and each planar portion extends in a plane that is generally orthogonal to the longitudinal axis. The guide wire extends through the elongate shaft and the distal end. The guiding sheath is slidable relative to the distal end to move the ridges between the collapsed configuration and the expanded configuration.

[0010] According to the disclosed technology, a system is also provided that includes a medical probe, a guide wire, and a rod or a wire. The medical probe includes a slender shaft and a distal end. The slender shaft extends along a longitudinal axis. The distal end includes a ridge frame that has a proximal end, a middle portion, and a distal end and extends along the longitudinal axis. The ridge frame includes a neck, a plurality of ridges, a first straight portion, a second straight portion, and a crown. The neck extends from the proximal end. The ridges extend along the middle portion. Each ridge includes (1) a first straight portion connected to the neck and (2) a second straight portion that includes a first end and a second end, and the first straight portion is connected to the second straight portion at a joint intermediate the first end and the second end. The crown is connected to the second straight portion and extends to the distal end. The ridge frame is movable between (1) a collapsed configuration and (2) an expanded configuration, in which, in the collapsed configuration, each connected first straight portion and second straight portion are oriented at a first angle relative to each other, and in the expanded configuration, each connected first straight portion and second straight portion are oriented at a second angle relative to each other, the second angle being less than the first angle. The guide wire extends through the slender shaft and the distal end. The rod or the wire is connected to one of the neck or the crown and is operable to move the ridge frame between the collapsed configuration and the expanded configuration.

[0011] According to the disclosed technology, a method of fabricating a distal end of a medical probe is also provided. The method includes the steps of cutting a tube that extends along a longitudinal axis to define a neck and a plurality of ridges. The method includes the steps of shaping the ridges such that each ridge includes a curved portion that curves away from the longitudinal axis and a planar portion that extends from the curved portion, each planar portion extending in a plane that is generally orthogonal to the longitudinal axis.

[0012] According to the disclosed technology, a method of fabricating a distal end of a medical probe is also provided. The method includes the steps of shaping a plurality of rods such that each rod includes (1) a first end that extends along the longitudinal axis, (2) a first curved portion that extends from the first end and curves away from the longitudinal axis, (3) a planar portion that extends from the curved portion that forms a generally annular shape, the planar portion extending in a plane that is generally orthogonal to the longitudinal axis; (4) a second curved portion that extends from the planar portion and curves toward the longitudinal axis, and (5) a second end that extends from the second curved portion and extends along the longitudinal axis. The method includes the steps of connecting the rods together such that the first end and the second end define an inner lumen.

[0013] According to the disclosed technology, a method of using a medical probe is also provided. The medical probe includes a distal end that includes a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along a longitudinal axis. The ridge frame includes a neck extending from the proximal end and a plurality of ridges connected to the neck and extending along the intermediate portion to the distal end. A plurality of electrodes are connected to the ridge frame. The method includes the steps of moving the ridges from (1) a collapsed configuration, in which the ridges extend along the longitudinal axis, to (2) an expanded configuration, in which each ridge includes a bent portion that curves away from the longitudinal axis and a planar portion that extends from the bent portion to the distal end, and each planar portion extends in a plane that is generally orthogonal to the longitudinal axis. The method includes the step of positioning the planar portion against a pulmonary vein opening such that the electrodes are placed in contact with the pulmonary vein opening.

[0014] According to the disclosed technology, a method of using a medical probe is also provided. The medical probe includes a distal end that includes a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along a longitudinal axis. The ridge frame includes a neck extending from the proximal end, a plurality of ridges extending along the intermediate portion, and a crown connected to a second straight portion and extending to the distal end. Each ridge includes a first straight portion connected to the neck and a second straight portion including a first end and a second end. The first straight portion is connected to the second straight portion at a joint intermediate the first end and the second end. The method includes the steps of moving the ridge frame from (1) a collapsed configuration, in which each connected first straight portion and second straight portion are oriented relative to each other at a first angle, to (2) an expanded configuration, in which each connected first straight portion and second straight portion are oriented relative to each other at a second angle, the second angle being less than the first angle. The method includes the step of positioning the second straight portion against a pulmonary vein opening such that the electrodes are placed in contact with the pulmonary vein opening. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic illustration of a medical system of a medical device including a medical probe having a distal end with electrodes according to the disclosed technology;

[0016] Figure 2A is a schematic illustration of a perspective view of a ridge frame of a distal end of a medical probe in a collapsed configuration according to the disclosed technology;

[0017] Figure 2B is a schematic illustration of a perspective view of a ridge frame of a Figure 2A in an expanded configuration according to the disclosed technology;

[0018] Figure 2Cis a schematic diagram showing a perspective view of the distal side of the ridge frame of Figure 2B in an expanded configuration according to the disclosed technology; Figure 2B

[0019] Figure 2D is a schematic diagram showing a perspective view of the proximal side of the distal end of Figure 2C in an expanded configuration according to the disclosed technology; Figure 2C

[0020] Figure 3 is a schematic diagram showing a cross-sectional view of the distal end of Figure 2C in a collapsed configuration and proximal to the ostium of the pulmonary vein according to the disclosed technology; Figure 2C

[0021] Figure 4 is a schematic diagram showing a cross-sectional view of the distal end of Figure 2C in an expanded configuration and pressed against the ostium of the pulmonary vein according to the disclosed technology; Figure 2C

[0022] Figure 5A is a schematic diagram showing a perspective view of another ridge frame of another distal end of a medical probe in an expanded configuration according to the disclosed technology;

[0023] Figure 5B is a schematic diagram showing a perspective view of the proximal side of the another distal end of the ridge frame of a medical probe having Figure 5A in an expanded configuration according to the disclosed technology; Figure 5A

[0024] Figure 6 is a schematic diagram showing a cross-sectional view of the distal end of Figure 5B in a collapsed configuration and proximal to the ostium of the pulmonary vein according to the disclosed technology; Figure 5B

[0025] Figure 7 is a schematic diagram showing a cross-sectional view of the distal end of Figure 5B in an expanded configuration and pressed against the ostium of the pulmonary vein according to the disclosed technology; Figure 5B

[0026] Figure 8A is a schematic diagram showing a perspective view of another ridge frame of another distal end of a medical probe in an expanded configuration according to the disclosed technology;

[0027] Figure 8B is a schematic diagram showing a perspective view of the proximal side of the another distal end of the ridge frame of a medical probe having Figure 8A in an expanded configuration according to the disclosed technology; Figure 8A

[0028] Figure 9 is a schematic diagram showing a cross-sectional view of the distal end of Figure 8B in a collapsed configuration and proximal to the ostium of the pulmonary vein according to the disclosed technology; Figure 8B ​​​​​​​​Schematic diagram of a cross-sectional view of the distal end;

[0029] Figure 10 is a schematic diagram showing, in an expanded configuration and pressing against the ostium of the pulmonary vein, according to the disclosed technology, Figure 8B Schematic diagram of a cross-sectional view of the distal end;

[0030] Figure 11A is a schematic diagram of a perspective view of another ridge frame of another distal end of a medical probe in an expanded configuration according to the disclosed technology;

[0031] Figure 11B is a schematic diagram showing, in a collapsed configuration, according to the disclosed technology, Figure 11A Perspective view of the ridge frame;

[0032] Figure 11C is a schematic diagram of a distal perspective view of another ridge frame of a medical probe having an expanded configuration according to the disclosed technology; Figure 11A Schematic diagram of the distal end;

[0033] Figure 11D is a schematic diagram showing, in an expanded configuration, according to the disclosed technology, Figure 11C Proximal perspective view of the distal end;

[0034] Figure 12 is a schematic diagram of a cross-sectional view of the distal end in a collapsed configuration and proximal to the ostium of the pulmonary vein, according to the disclosed technology; and Figure 11C Schematic diagram of a cross-sectional view of the distal end;

[0035] Figure 13 is a schematic diagram showing, in an expanded configuration and pressing against the ostium of the pulmonary vein, according to the disclosed technology, Figure 11C Schematic diagram of a cross-sectional view of the distal end. Detailed Description

[0036] The following detailed description should be read in conjunction with the accompanying drawings, in which like reference numerals are used for like elements in the different drawings. The drawings (not necessarily to scale) depict selected examples and are not intended to limit the scope of the disclosure. The detailed description illustrates, by way of example and not limitation, the principles of the technology disclosed in the present invention. This description will clearly enable those skilled in the art to make and use the technology disclosed in the present invention, and describes several embodiments, adaptations, variations, alternative forms, and uses of the technology disclosed in the present invention, including what is presently believed to be the best mode of carrying out the technology disclosed in the present invention.

[0037] As used herein, the term "about" or "approximately" or "substantially" with respect to any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or components to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of values of ±20% of the recited value, e.g., "about 90%" can refer to a range of values from 71% to 110%. In addition, as used herein, the terms "patient", "recipient", "user", and "subject" refer to any human or animal subject, and are not intended to limit the system or method to human use, but the use of the subject technology in human patients represents a preferred embodiment. Similarly, the term "proximal" refers to a position closer to the operator or physician, while "distal" refers to a position farther from the operator or physician.

[0038] As discussed herein, the vasculature of a "patient", "recipient", "user", and "subject" can be that of a human or any animal. It should be understood that the animal can be of any suitable type, including but not limited to mammals, veterinary animals, domestic animals, or pet animals, etc. For example, the animal can be an experimental animal (e.g., rats, dogs, pigs, monkeys, etc.) specifically selected to have certain characteristics similar to humans. It should be understood that the subject can be, for example, any suitable human patient.

[0039] As discussed herein, an "operator" can include a doctor, surgeon, technician, scientist, or any other individual or delivery instrument associated with delivering a multi-electrode catheter for treating drug-refractory atrial fibrillation to a subject.

[0040] As discussed herein, when referring to the devices and corresponding systems of the present disclosure, the term "ablation" refers to components and structural features configured to reduce or prevent the generation of unstable cardiac signals in cells by utilizing non-thermal energy (such as irreversible electroporation (IRE)), which can be interchangeably referred to as pulsed electric field (PEF) and pulsed field ablation (PFA) in the present disclosure. "Ablation" as used throughout the present disclosure, when referring to the devices and corresponding systems of the present disclosure, refers to non-thermal ablation of cardiac tissue for certain conditions, including but not limited to arrhythmia, atrial flutter ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The term "ablation" also includes known methods, devices, and systems for achieving various forms of ablation of body tissue understood by those skilled in the relevant art.

[0041] As discussed herein, the terms "bipolar" and "unipolar", when used to refer to ablation regimens, describe ablation regimens that differ in terms of current path and electric field distribution. "Bipolar" refers to an ablation regimen that utilizes a current path between two electrodes, both of which are positioned at the treatment site, as described below; the current density and electric flux density at each of the two electrodes are typically approximately equal. "Unipolar" refers to an ablation regimen that utilizes a current path between two electrodes, where one electrode with a high current density and high electric flux density is positioned at the treatment site and a second electrode with a relatively low current density and low electric flux density is positioned away from the treatment site.

[0042] As discussed herein, the terms "tubular", "tube", and "shaft" should be understood broadly and are not limited to structures that are right circular cylinders or have a fully circular cross-section or a uniform cross-section along their entire length. For example, a tubular / shaft structure is typically illustrated as a structure that is substantially a right circular cylinder. However, without departing from the scope of the present disclosure, a tubular / shaft structure may have a tapered or curved outer surface.

[0043] The present disclosure relates to systems, methods, or uses, and devices for performing IRE ablation of cardiac tissue to treat arrhythmias. Ablation energy is typically provided to cardiac tissue by the distal portion of a catheter, which can deliver ablation energy along the tissue to be ablated. Some example catheters include a three-dimensional structure at the distal portion and are configured to apply ablation energy from various electrodes positioned on the three-dimensional structure. Fluoroscopy can be used to visualize ablation procedures incorporating such example catheters.

[0044] The use of thermal techniques such as radiofrequency (RF) energy and cryoablation for cardiac tissue ablation of a malfunctioning heart is a well-known procedure. Generally, in order to successfully ablate using a thermal technique, it is necessary to measure cardiac electrode potentials at various locations in the myocardium. In addition, temperature measurements during ablation provide data that can enable ablation efficacy. Typically, for ablation procedures using thermal ablation, electrode potentials and temperatures are measured before, during, and after actual ablation. RF methods can have risks that may result in tissue charring, burns, steam pops, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulas. Cryoablation is an alternative to RF ablation that can reduce some of the thermal risks associated with RF ablation. However, compared to RF ablation, manipulating a cryoablation device and selectively applying cryoablation is generally more challenging; thus, cryoablation is not feasible in certain anatomical geometries that can be reached by an electroablation device.

[0045] The present disclosure may include electrodes configured for irreversible electroporation (IRE), RF ablation, and / or cryoablation. Throughout the present disclosure, IRE may be interchangeably referred to as pulsed electric field (PEF) ablation and pulsed field ablation (PFA). As discussed in the present disclosure, IRE is a non-thermal cell death technique that can be used for atrial arrhythmia ablation. To perform ablation using IRE / PEF, biphasic voltage pulses are applied to disrupt the cellular structure of the myocardium. The biphasic pulses are non-sinusoidal and can be tuned based on the electrophysiology of the cells to target the cells. In contrast, to perform ablation using RF, a sinusoidal voltage waveform is applied to generate heat at the treatment area, heating all cells indiscriminately in the treatment area. Thus, IRE has the ability to avoid adjacent thermosensitive structures or tissues, which would be beneficial in reducing possible complications known to be affected by ablation or dissection modalities. Additionally or alternatively, monophasic pulses may be used.

[0046] Electroporation can be induced by applying a pulsed electric field across biological cells such that pores are generated reversibly (temporarily) or irreversibly (permanently) in the cell membrane. When a pulsed electric field is applied, the cell has a transmembrane electrostatic potential that rises above the resting potential. When the transmembrane electrostatic potential remains below the threshold potential, the electroporation is reversible, meaning that the pores can close when the applied pulsed electric field is removed and the cell can repair itself and survive. If the transmembrane electrostatic potential rises above the threshold potential, the electroporation is irreversible and the cell becomes permanently permeable. Thus, the cell dies due to the loss of homeostasis and typically dies by apoptosis. Generally, different types of cells have different threshold potentials. For example, cardiac cells have a threshold potential of approximately 500 V / cm, while for bone, the threshold potential is 3000 V / cm. These differences in threshold potential allow IRE to selectively target tissues based on the threshold potential.

[0047] The techniques of the present disclosure include systems and methods for applying an electrical signal from a catheter electrode positioned near myocardial tissue to generate ablation energy to ablate the myocardial tissue. In some examples, the systems and methods can effectively ablate the target tissue by inducing irreversible electroporation. In some examples, the systems and methods can effectively induce reversible electroporation as part of a diagnostic procedure. Reversible electroporation occurs when the electricity applied using the electrode is below the electric field threshold of the target tissue that allows the cells to repair. Reversible electroporation does not kill the cells but allows the physician to view the effect of the reversible electroporation on the electrical activation signals near the target location. Exemplary systems and methods for reversible electroporation are disclosed in U.S. Patent Publication 2021 / 0162210, the entire content of which is incorporated herein by reference.

[0048] The efficacy of pulsed electric fields and their induction of reversible electroporation and / or irreversible electroporation may be affected by the physical parameters of the system and the biphasic pulse parameters of the electrical signal. Physical parameters may include electrode contact area, electrode spacing, electrode geometry, etc. The examples presented herein generally include physical parameters suitable for effectively inducing reversible electroporation and / or irreversible electroporation. The biphasic pulse parameters of the electrical signal may include voltage amplitude, pulse duration, pulse interphase delay, interpulse delay, total application time, delivered energy, etc. In some examples, the parameters of the electrical signal can be adjusted to induce both reversible and irreversible electroporation given the same physical parameters. Examples of various ablation systems and methods including IRE are presented in U.S. Patent Publications 2021 / 0169550A1, 2021 / 0169567A1, 2021 / 0169568A1, 2021 / 0161592A1, 2021 / 0196372A1, 2021 / 0177503A1, and 2021 / 0186604A1, the entire contents of each of which are incorporated herein by reference.

[0049] Reference Figure 1 , which shows an exemplary catheter-based electrophysiological mapping and ablation system 10. System 10 includes a plurality of catheters that are inserted by a physician 24 through the vasculature of a patient 23 via the skin into the chambers or vascular structures of the heart 12. Generally, a delivery sheath catheter is inserted into the left atrium or right atrium near a desired location in the heart 12. Then, a plurality of catheters can be inserted into the delivery sheath catheter to reach that desired location, such as the ostium 34 of the pulmonary vein (PV). The plurality of catheters can include catheters dedicated to sensing intracardiac electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. An exemplary medical device / probe configured for sensing IEGM is illustrated herein, such as catheter 14 (also synonymously referred to herein as probe 14). The physician 24 brings the distal end of the catheter 14 into contact with the heart wall for sensing a target site in the heart 12. For ablation, the physician 24 similarly brings the distal end of the ablation catheter to the target site for ablation.

[0050] Catheter 14 is an exemplary catheter that includes one and preferably a plurality of electrodes 26 configured to sense IEGM signals. In the examples described herein, electrodes 26 may be configured to deliver ablation energy (IRE and / or RF) to tissue in heart 12. In addition to delivering ablation energy using electrodes 26, electrodes 26 may also be used to determine the position of end effector 100 and / or measure physiological properties, such as local surface potential at corresponding positions on tissue in heart 12. Electrodes 26 may be biased such that a greater portion of electrodes 26 faces outward from end effector 100, such that electrodes 26 deliver a greater amount of electrical energy outward away from end effector 100 (i.e., toward heart 12 tissue) rather than inward toward end effector 100.

[0051] Examples of materials that are ideally suited to form electrodes 26 include gold, platinum, and palladium (and their respective alloys). These materials also have high thermal conductivity, which allows the minimal heat generated on tissue (i.e., by ablation energy delivered to tissue) to be conducted through the electrodes to the back side of the electrodes (i.e., the portion of electrodes 26 on the inner side of the ridge), and then to the blood pool in heart 12.

[0052] Catheter 14 may additionally include a position sensor embedded in or near distal tip 28 for tracking the position and orientation of distal tip 28. Optionally and preferably, the position sensor is a magnetic-based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0053] The magnetic-based position sensor may operate in conjunction with a positioning pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predefined workspace. The real-time position of distal tip 28 of catheter 14 may be tracked based on the magnetic field generated by positioning pad 25 and sensed by the magnetic-based position sensor. Details of magnetic-based position sensing techniques are described in U.S. Pat. Nos. 5,391,199, 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, 6,892,091, each of which is incorporated herein by reference.

[0054] System 10 includes one or more electrode patches 38 that are positioned to contact the skin of 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 such 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. Pat. Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, each of which is incorporated herein by reference.

[0055] Recorder 11 displays the electrogram 21 captured using the body surface ECG electrodes 18 and the intracardiac electrogram (IEGM) captured using the electrodes 26 of the catheter 14. Recorder 11 may include pacing capabilities for pacing the heart rhythm and / or may be electrically connected to an independent pacemaker.

[0056] System 10 may include an ablation energy generator 50 that is adapted to conduct ablation energy to one or more electrodes at the distal tip of a catheter configured for ablation. The energy generated by ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy or pulsed field ablation (PFA) energy (including monopolar or bipolar high voltage direct current (DC) or alternating current (AC) pulses that can be used to effect irreversible electroporation (IRE)), or combinations thereof.

[0057] The patient interface unit (PIU) 30 is an interface configured to establish electrical connectivity between the catheter, electrophysiology equipment, power supply, and a workstation 55 for controlling the operation of system 10. The electrophysiology equipment of system 10 may include, for example, multiple catheters, positioning pad 25, body surface ECG electrodes 18, electrode patches 38, ablation energy generator 50, and recorder 11. Optionally and preferably, PIU 30 further includes processing capabilities for performing real-time calculations of the position of the catheter and for performing ECG calculations.

[0058] Workstation 55 includes a memory, a processor unit with a memory or storage device loaded with appropriate operating software, and user interface capabilities. Workstation 55 can provide multiple functions, optionally including: (1) performing three-dimensional (3D) modeling of endocardial anatomy and rendering a model or anatomical map 20 for display on a display device 27; (2) displaying an activation sequence (or other data) compiled from the recorded electrograms 21 as representative visual markers or images superimposed on the rendered anatomical map 20 on the display device 27; (3) displaying the real-time position and orientation of multiple catheters within a heart chamber; and (5) displaying a site of interest on the display device 27, such as where ablation energy has been applied. A commercial product embodying the elements of system 10 may be the CARTO TM 3System, available from Biosense Webster, Inc., 31 Technology Drive, Suite 200, Irvine, CA 92618, USA.

[0059] Figure 2A FIG. 6 is a schematic diagram showing a perspective view of the ridge frame 100 at the distal end 28 of the medical probe 14 in a collapsed configuration. Figure 2B FIG. 7 is a schematic diagram showing a perspective view of the ridge frame 100 in an expanded configuration. Figure 2C FIG. 8 is a schematic diagram showing a perspective view of the distal side of the distal end 28 of the ridge frame 100 in an expanded configuration. Figure 2D FIG. 9 is a schematic diagram showing a perspective view of the proximal side of the distal end of the Figure 2C ridge frame 100 in an expanded configuration.

[0060] Now referring to Figure 2A and Figure 2B , the distal end 28 of the catheter / medical probe 14 can be defined by a ridge frame 100 that extends along a longitudinal axis 60 and has a proximal end 100A, an intermediate portion 100B, and a distal end 100C. The frame 100 includes a neck 102 (which extends from the proximal end 100A) and a plurality of ridges 104 (which extend along the intermediate portion 100B to the distal end 100C), and the ridges are connected to and extend from the neck 102. In addition, the frame 100 defines a lumen 130 that is coaxial with the longitudinal axis 60 (see Figure 4 ).

[0061] In some examples, the frame 100 is integral (i.e., a monolithic structure). The frame 100 can be formed from flat or cylindrical tube stock using any suitable method. For example, the frame 100 can be formed by cutting, laser cutting, stamping, combinations thereof, etc., such that the frame is separated to form the ridges 104 and define the neck 102.

[0062] The frame 100 comprises a flexible, elastic material (e.g., a shape memory alloy such as nickel-titanium, also known as nitinol), which is shape-set to be biased to bend outwardly to an expanded configuration, as Figure 2B shown. In the expanded configuration, the frame 100 resembles a lily flower. Due to the flexible, elastic properties of the material, the ridges 104 can also be moved to a collapsed configuration (as Figure 2A shown), in which the ridges 104 extend along the longitudinal axis 60. In the expanded configuration, each ridge 104 has a bent portion 104A that curves away from the longitudinal axis 60 and a planar portion 104A that extends linearly from the bent portion 104B along a plane 120 and terminates at the distal end 100C of each ridge 104. As Figure 2B shown, the plane 120 is generally orthogonal to the longitudinal axis 60.

[0063] Turning now to Figure 2C and Figure 2D , to form the distal end 28 of the probe 14, the ridge frame 100 is connected to a flexible elongate shaft 80. A flexible membrane 110 is also connected to the ridge frame 100 on one side of the ridges 104, which faces distally (relative to the proximal end of the probe 14) in the expanded configuration and faces inwardly in the collapsed configuration. More specifically, a first portion of the flexible membrane 110 is connected to the planar portion 104B of each ridge 104 (so as to form a planar surface coplanar with the plane 120), and a second portion of the membrane 110 is further connected to the arcuate portion 104A of each ridge (this portion of the membrane 110 resembles a curved funnel in appearance). In some examples, the flexible membrane 110 is made of a biocompatible elastomeric material.

[0064] Specifically as Figure 2C shown, a plurality of electrodes 26 are formed on the distally facing surface of the flexible membrane 110, and these electrodes are shaped to maximize contact with the affected area of the heart 12. More specifically, the electrodes 26 are formed at least on the first portion of the flexible membrane 110 such that at least a portion of each electrode 26 is disposed on or parallel to the plane 120. The electrodes 26 shown in this example can be made, for example, using conductive epoxy resin, using a flexible printed circuit board (PCB), or by a vapor deposition layer.

[0065] Figure 3 is a schematic diagram showing a cross-sectional view of the distal end 28 of Figure 2C in a collapsed configuration and proximal to the ostium 34 of the pulmonary vein PV. Figure 4 is a schematic diagram showing a cross-sectional view of the distal end 28 of Figure 2C in an expanded configuration and pressed against the ostium 34 of the pulmonary vein PV.

[0066] Specific reference is made to Figures 3 to 4, in addition to the medical probe 14, the system according to the present disclosure also includes a guide wire 70 and a guiding sheath 90. The guide wire 70 is guided through the frame lumen 130 of the distal end 28, through the lumen 82 of the elongate shaft 80, to the proximal end of the medical probe (which includes, for example, a handle). The guiding sheath 90 is slidable relative to the distal end 28 of the medical probe 14 and will be described in more detail below.

[0067] By way of example, the following description assumes that a target region (such as the ostium 34 of the pulmonary vein PV) is to be ablated. Of course, it should be understood that the techniques described herein can be used to ablate and / or map other regions of the heart 12.

[0068] In an initial step, the physician 24 inserts the distal end 28 and the guide wire 70 into the subject, where the guiding sheath 90 is disposed around the distal end 28 in a manner that forces the ridge frame 100 into a collapsed configuration (from their shape-set inflated configuration). The guide wire 70 is then navigated into the heart 12. In this example, within the heart 12, the guide wire 70 is navigated into the pulmonary vein PV.

[0069] After the guide wire 70 has been guided into the pulmonary vein PV, the ridge frame 100, the elongate shaft 80, and the guiding sheath 90 are slid along the guide wire 70 until they are positioned near the ostium 34. Once the distal end 28 of the probe is properly positioned, the guiding sheath 90 can be actuated in the proximal direction (to the left as shown in Figure 4 the direction shown and as indicated by the direction arrow). This actuation exposes the distal end 28, which causes the ridges 104 to bend outwardly to their shape-set form (i.e., the inflated configuration). Once in the inflated configuration, the distal-facing plane of the flexible membrane 110 including the electrodes 26 is pressed against the ostium 34. The flat contact surface of the flexible membrane 110 and the electrodes 26 maximizes its contact area with the ostium 34.

[0070] In the ablation step, the physician 24 operates the processor 55 and the ablation energy generator 50 to supply current to the electrodes 26 of the flexible membrane 110. If there are two or more electrodes 26, the current provided can be bipolar, i.e., the current can flow between the electrodes 26 to deliver ablation energy to the tissue. Alternatively, the ablation energy provided can be monopolar, i.e., the current can be applied between one of the electrodes 26 and a return electrode connected to the generator 50. The return electrode can be disposed outside the patient 23. For example, the return electrode can include a patch (such as patch 38, etc.) coupled to the patient's body.

[0071] In some examples, an RF sinusoidal (alternating current) is provided to electrode 26 such that RF ablation of tissue is performed. Alternatively, a pulsed current (e.g., direct current or alternating current) may be provided to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is provided to perform PFA, monopolar ablation energy may be provided by a current flowing between electrode 26 on flexible membrane 110 and electrode patch 38 or a patch. Additionally, bipolar ablation energy may be supplied by a current flowing between electrode 26 on flexible membrane 110 itself and another catheter within another portion of heart 12.

[0072] Depending on the placement and arrangement of electrode 26 on flexible membrane 110, a substantially complete 360-degree ablation zone may be achieved around ostium 34 to provide pulmonary vein isolation. Electrode 26 may be therapeutically operative, e.g., for ablation of the ostium, where each electrode ablates a predetermined region of the circumference around ostium 34 to isolate the pulmonary vein, without the need to reposition distal tip 28 one or more times during the treatment.

[0073] Optionally, electrode 26 may also be used to assist in positioning distal tip 28 and / or sensing anatomical signals at ostium 34. For example, the position of electrode 26 may be verified by the current tracking module of PIU 30 using the impedance and / or current between electrode 26 and patch 38. Additionally, the position of the electrode may be verified by fluoroscopy. Once electrode 26 is properly positioned in contact with ostium 34, electrode 26 generates a potential gradient signal in response to the sensed electrical potential, also referred to herein as an electrical signal. In some examples, the sensed electrical signal indicates at least one characteristic of the anatomical signal, such as the direction and propagation speed of a wavefront caused by an anatomical signal (such as an electrocardiogram (ECG) signal in heart 12).

[0074] After ablation and / or mapping is complete, physician 24 may slightly retract distal tip 28 from the ostium and slide guide sheath 90 backward over distal tip 28, which causes ridge 104 to bend inward from the expanded configuration into the collapsed configuration. Once ridge 104 is collapsed, guide sheath 90, medical probe 14, and guide wire 70 may be withdrawn from the patient's body. Of course, while guide sheath 90 has been described as the device that causes ridge frame 100 to expand and collapse, it should be understood that other forms of actuating ridge frame 100 between the expanded configuration and the collapsed configuration (and vice versa) may be employed without departing from the spirit and scope of the present disclosure.

[0075] Figure 5A is a schematic illustration of a perspective view of another ridge frame 200 of another distal tip 28 of medical probe 14 in the expanded configuration. Figure 5B is a view showing a medical probe 14 with Figure 5ASchematic illustration of a distal perspective view of the distal end 28 of the ridge frame 200.

[0076] Now refer to Figure 5A , the distal end 28 of another exemplary catheter / medical probe 14 may be defined by a ridge frame 200 that extends along a longitudinal axis 60 and has a proximal end, an intermediate portion, and a distal end (similar to the frame 100 described previously). As Figure 5A shown, the frame 200 may be formed similarly or identically to the frame 100. The frame 200 includes a neck 202 (which extends from the proximal end) and a plurality of ridges 204 (which extend along the intermediate portion to the distal end), and the ridges are connected to the neck 102 and extend from the neck. In addition, the frame 200 defines a lumen 230 that is coaxial with the longitudinal axis 60 (see Figure 7 ).

[0077] In some examples, the frame 200 is integral (i.e., a monolithic structure). Similar to the examples described previously, the frame 200 can be formed from flat or cylindrical tube stock using any suitable method. For example, the frame 200 can be formed by cutting, laser cutting, stamping, combinations thereof, etc., such that the frame is separated to form the ridges 204 and define the neck 202.

[0078] The frame 200 comprises a flexible, elastic material (e.g., a shape memory alloy such as nickel-titanium, also known as nitinol), which is shape-set to be biased to bend outwardly to an expanded configuration, as Figure 5B shown. In the expanded configuration, the frame 200 resembles a lily. Due to the flexible, elastic properties of the material, the ridges 204 can also move to a collapsed configuration (as Figure 6 shown), in which the ridges 204 extend along the longitudinal axis 60. In the expanded configuration, each ridge 204 has a curved portion 204A that bends away from the longitudinal axis 60 and a planar portion 204B that extends linearly from the curved portion 204A along a plane 220 and terminates at the distal end of each ridge 204. As Figure 5A shown, the plane 220 is generally orthogonal to the longitudinal axis 60.

[0079] Now turn to Figure 5B, to form the distal end 28 of the probe 14, the ridge frame 100 is connected to the flexible elongate shaft 80. Additionally, a plurality of electrodes 26 are formed on or around each ridge 204 to maximize contact with the affected area of the heart 12 (discussed in more detail below). More specifically, the electrodes 26 are formed at least on the planar portion 204B of the ridge 204 such that at least a portion of each electrode 26 is disposed on or parallel to the plane 220. The electrodes 26 shown in this example can be made, for example, using conductive epoxy, using a flexible printed circuit board (PCB), by vapor deposition layers, or using toroidal electrodes.

[0080] A flexible membrane 210 can also be attached to surround each ridge 204. In some examples, the flexible membrane 210 is made of a biocompatible insulating material.

[0081] Figure 6 is a schematic illustration of a cross-sectional view of the Figure 5B distal end 28 in a collapsed configuration and proximal to the ostium 34 of the pulmonary vein PV. Figure 7 is a schematic illustration of a cross-sectional view of the Figure 5B distal end 28 in an expanded configuration and pressed against the ostium 34 of the pulmonary vein PV.

[0082] Specifically referring to Figures 6 to 7 , in addition to the medical probe 14, the system according to the disclosed technology also includes a guidewire 70 and a guiding sheath 90. The guidewire 70 is guided through the frame lumen 230 of the distal end 28, through the lumen 82 of the elongate shaft 80, to the proximal end of the medical probe (which includes, for example, a handle). The guiding sheath 90 is slidable relative to the distal end 28 of the medical probe 14 and is described in more detail below.

[0083] By way of example, the following description assumes that a target region (such as the ostium 34 of the pulmonary vein PV) will be ablated. Of course, it should be understood that the presently described techniques can be used to ablate and / or map other regions of the heart 12.

[0084] In an initial step, the physician 24 inserts the distal end 28 and the guidewire 70 into the subject, with the guiding sheath 90 surrounding the distal end 28 in a manner that forces the ridge frame 200 into a collapsed configuration (from its shape-set expanded configuration). The guidewire 70 is then navigated into the heart 12. In this example, within the heart 12, the guidewire 70 is navigated into the pulmonary vein PV.

[0085] After the guidewire 70 has been guided into the pulmonary vein PV, the ridge frame 100, the elongate shaft 80, and the guiding sheath 90 are slid along the guidewire 70 until they are positioned near the ostium 34. Once the distal end 28 of the probe 14 is properly positioned, the guiding sheath 90 can be actuated in the proximal direction (relative toFigure 7 The direction shown in [Figure] is to the left and as indicated by the direction arrow). This actuation exposes the distal end 28, which causes the ridges 204 to bend outwardly to their shape-setting form (i.e., the inflated configuration). Once in the inflated configuration, the distally-facing planar portion 204B of the ridges 204, which includes the electrodes 26, is pressed against the ostium 34. The flat contact surface 220 on which the electrodes 26 are disposed maximizes their contact area with the ostium 34.

[0086] During the ablation step, the physician 24 operates the processor 55 and the ablation energy generator 50 to supply current to the electrodes 26 on the ridges 204. If there are two or more electrodes 26, the current provided may be bipolar, i.e., the current may flow between the electrodes 26 to deliver ablation energy to the tissue. Alternatively, the ablation energy provided may be monopolar, i.e., the current may be applied between one of the electrodes 26 and a return electrode connected to the generator 50. The return electrode may be disposed outside the patient 23. For example, the return electrode may include a patch (e.g., patch 38, etc.) coupled to the patient's body.

[0087] In some examples, an RF sinusoidal (alternating current) current is provided to the electrodes 26 such that RF ablation of the tissue is performed. Alternatively, a pulsed current (e.g., direct current or alternating current) may be provided to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is provided to perform PFA, monopolar ablation energy may be provided by the current flowing between the electrodes 26 on the ridges 204 and the electrode patch 38 or patch. Additionally, bipolar ablation energy may be supplied by the current flowing between the electrodes 26 themselves and / or another catheter within another part of the heart 12.

[0088] Depending on the placement and arrangement of the electrodes 26 on the ridges 204, a substantially complete 360-degree ablation band may be achieved around the ostium 34 to provide pulmonary vein isolation. The electrodes 26 may be therapeutically effective, e.g., for ablation of the ostium, where each electrode ablates a predetermined region of the circumference around the ostium 34 to isolate the pulmonary vein, without the need to reposition the distal end 28 one or more times during the treatment.

[0089] Optionally, electrode 26 can also be used to assist in localizing the distal tip 28 and / or sensing the anatomical signals at the port 34. For example, the position of electrode 26 can be verified by the current tracking module of the PIU 30 using the impedance and / or current between electrode 26 and patch 38. Additionally, the position of the electrode can be verified by fluoroscopy. Once electrode 26 is properly positioned in contact with port 34, electrode 26 generates an electric potential gradient signal in response to the sensed electric potential, also referred to herein as an electrical signal. In some examples, the sensed electrical signal indicates at least one characteristic of the anatomical signal, such as the direction and propagation speed of a wavefront caused by an anatomical signal, such as an electrocardiogram (ECG) signal in the heart 12.

[0090] After ablation and / or mapping is completed, the physician 24 can slightly retract the distal tip 28 from the port and slide the guide sheath 90 backward over the distal tip 28, which causes the ridge 204 to bend inward from the expanded configuration into the collapsed configuration. Once the ridge 204 is collapsed, the guide sheath 90, the medical probe 14, and the guide wire 70 can be withdrawn from the patient's body. Of course, while the guide sheath 90 has been described as the device that causes the ridge frame 200 to expand and collapse, it should be understood that other forms of actuating the ridge frame 200 between the expanded configuration and the collapsed configuration (and vice versa) can be employed without departing from the spirit and scope of the present disclosure.

[0091] Figure 8A is a schematic illustration showing a perspective view of another ridge frame 300 of another exemplary distal tip 28 of the medical probe 14 in the expanded configuration. Figure 8B is showing a medical probe 14 with Figure 8A a perspective view of the distal side of the distal tip 28 of the ridge frame 300 in the expanded configuration.

[0092] Now referring to Figure 8A , another exemplary distal tip 28 of the catheter / medical probe 14 can be defined by a ridge frame 300 that extends along the longitudinal axis 60 and has a proximal end, an intermediate portion, and a distal end (similar to the frames 100, 200 described previously). As Figure 8A shown, the frame 300 can be shaped to take a shape similar to the frames 100, 200 in the expanded configuration. The frame 300 includes a neck 302 (which extends from the proximal end) and a plurality of ridges 304 (which extend along the intermediate portion to the distal end), which are connected to the neck 302 and extend from the neck. Additionally, the frame 300 defines a lumen 330 that is coaxial with the longitudinal axis 60 (see Figure 10 ).

[0093] In some examples, the frame 300 is formed by a series of flexible, elastic rods or tubes (e.g., formed of a shape memory alloy such as nitinol), each rod or tube including a first end 302A and a second end 302B of a portion defining a neck 302 (when assembled / connected together, all of the ends of the first end 302A and the second end 302B together form a neck 302 defining a lumen 330). As Figure 8A shown, each rod is bent to include a loop portion 304 forming a ridge 304 of the frame 300, and is shaped to be biased to bend outwardly to an expanded configuration. In the expanded configuration, each bent rod resembles a petal. Due to the flexible, elastic properties of the material, the ridge 304 can also be moved to a collapsed configuration (as Figure 9 shown), in which the ridge 304 extends along the longitudinal axis 60.

[0094] In the expanded configuration, each loop portion 304 has two bent portions 304A that bend away from the longitudinal axis 60 and a planar portion 304B that linearly extends from the bent portion 304A along a plane 320 and encircles at the distal end of each ridge 304. In other words, the planar portion 304B forms a ring from the first end 302A toward the second end 302B and connects the bent portions 304A, thereby forming a partial ring. As Figure 8A shown, the plane 320 is generally orthogonal to the longitudinal axis 60.

[0095] Turning now to Figure 8B , to form the distal end 28 of the probe 14, the ridge frame 300 is connected to the flexible elongate shaft 80. Additionally, a plurality of electrodes 26 are formed on or around the planar portion 304B of each ridge 304 to maximize contact with the affected area of the heart 12 (discussed in more detail below). More specifically, the electrodes 26 are formed on the ridge 304 such that at least a portion of each electrode 26 is disposed on or parallel to the plane 320. The electrodes 26 shown in this example can be made, for example, using conductive epoxy, using a flexible printed circuit board (PCB), by a vapor deposition layer, or using annular electrodes.

[0096] A flexible membrane 310 can also be attached to surround each ridge 304 and neck 302. In some examples, the flexible membrane 310 is made of a biocompatible insulating material.

[0097] Figure 9 is a schematic illustration of a cross-sectional view of the distal end 28 of Figure 8B shown in a collapsed configuration and proximal to the ostium 34 of the pulmonary vein PV. Figure 10 is a schematic illustration of a cross-sectional view of the distal end 28 of Figure 8B shown in an expanded configuration and pressed against the ostium 34 of the pulmonary vein PV.

[0098] Specific reference Figures 9 to 10 , in addition to the medical probe 14, the system according to the present disclosure technology further includes a guide wire 70 and a guiding sheath 90. The guide wire 70 is guided through the frame lumen 330 of the distal end 28, through the lumen 82 of the elongate shaft 80, and to the proximal end of the medical probe (which includes, for example, a handle). The guiding sheath 90 is slidable relative to the distal end 28 of the medical probe 14 and is described in more detail hereinafter.

[0099] By way of example, the following description assumes that a target region (such as the ostium 34 of the pulmonary vein PV) is to be ablated. Of course, it should be understood that the currently described technology can be used to ablate and / or map other regions of the heart 12.

[0100] In an initial step, the physician 24 inserts the distal end 28 and the guide wire 70 into the subject, wherein the guiding sheath 90 is disposed around the distal end 28 in a manner that forces the ridge frame 300 into a collapsed configuration (from their shape-set inflated configuration). The guide wire 70 is then navigated into the heart 12. In this example, within the heart 12, the guide wire 70 is navigated into the pulmonary vein PV.

[0101] After the guide wire 70 has been guided into the pulmonary vein PV, the ridge frame 300, the elongate shaft 80, and the guiding sheath 90 slide along the guide wire 70 until they are positioned near the ostium 34. Once the distal end 28 of the probe 14 is properly positioned, the guiding sheath 90 can be actuated in the proximal direction (relative to Figure 10 the direction shown to the left in and as indicated by the direction arrow). This actuation exposes the distal end 28, which causes the ridges 304 to bend outwardly to their shape-set form (i.e., the inflated configuration). Once in the inflated configuration, the distal-facing planar portion 304B of the ridges 304 including the electrodes 26 is pressed against the ostium 34, as Figure 10 shown. The flat contact surface 320 on which the electrodes 26 are disposed maximizes its contact area with the ostium 34.

[0102] In the ablation step, the physician 24 operates the processor 55 and the ablation energy generator 50 to supply current to the electrodes 26 on the ridges 304. If there are two or more electrodes 26, the supplied current can be bipolar, i.e., the current can flow between the electrodes 26 to transfer ablation energy to the tissue. Alternatively, the supplied ablation energy can be monopolar, i.e., the current can be applied between one of the electrodes 26 and a return electrode connected to the generator 50. The return electrode can be disposed outside the patient 23. For example, the return electrode can include a patch (e.g., patch 38, etc.) coupled to the patient's body.

[0103] In some examples, an RF sinusoidal (alternating current) current is provided to electrode 26 such that RF ablation of tissue is performed. Alternatively, a pulsed current (e.g., direct current or alternating current) may be provided to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is provided to perform PFA, monopolar ablation energy may be provided by a current flowing between electrode 26 on ridge 204 and electrode patch 38 or the patch. Additionally, bipolar ablation energy may be supplied by a current flowing between electrode 26 itself and / or another catheter within another part of heart 12.

[0104] Depending on the placement and arrangement of electrode 26 on ridge 304, a substantially complete 360-degree ablation band may be achieved around ostium 34 to provide pulmonary vein isolation. Electrode 26 may be therapeutically operative, e.g., for ablation of the ostium, where each electrode ablates a predetermined region of the circumference around ostium 34 to isolate the pulmonary vein, without the need to reposition distal tip 28 one or more times during the treatment.

[0105] Optionally, electrode 26 may also be used to assist in positioning distal tip 28 and / or sensing anatomical signals at ostium 34. For example, the position of electrode 26 may be verified by the current tracking module of PIU 30 using the impedance and / or current between electrode 26 and patch 38. Additionally, the position of the electrode may be verified by fluoroscopy. Once electrode 26 is properly positioned in contact with ostium 34, electrode 26 generates a potential gradient signal in response to the sensed electrical potential, also referred to herein as an electrical signal. In some examples, the sensed electrical signal indicates at least one characteristic of the anatomical signal, such as the direction and propagation speed of a wavefront caused by an anatomical signal (such as an electrocardiogram (ECG) signal in heart 12).

[0106] After ablation and / or mapping is complete, physician 24 may slightly retract distal tip 28 from ostium 34 and slide guide sheath 90 backward over distal tip 28, which causes ridge 304 to bend inward from the expanded configuration into the collapsed configuration. Once ridge 304 is collapsed, guide sheath 90, medical probe 14, and guide wire 70 may be withdrawn from the patient's body. Of course, while guide sheath 90 has been described as the device that causes ridge frame 300 to expand and collapse, it should be understood that other forms of actuating ridge frame 300 between the expanded configuration and the collapsed configuration (and vice versa) may be employed without departing from the spirit and scope of the present disclosure.

[0107] Figure 11A is a schematic illustration showing a perspective view of ridge frame 400 of another distal tip 28 of medical probe 14 in the expanded configuration. Figure 2B is a schematic illustration showing Figure 11A in the collapsed configuration Figure 2CIs a schematic illustration showing a perspective view of the distal side of the distal end 28 of the ridge frame 400 in an expanded configuration. Figure 2D Is a schematic illustration showing Figure 2C a perspective view of the proximal side of the distal end 28 of

[0108] Now referring to Figure 11A , the distal end 28 of another exemplary catheter / medical probe 14 can be defined by a ridge frame 400 that extends along a longitudinal axis 60 and has a proximal end 400A, an intermediate portion 400B, and a distal end 400C (similar to the frames 100, 200, 300 described previously). As Figure 11A shown, the framework 400 can be shaped to take a shape similar to a basket catheter. The frame 400 includes a neck 402 (which extends from the proximal end 400A) and a plurality of ridges 404 (which extend along the intermediate portion 400B), and the ridges are connected to the neck 402 and extend from the neck. The ridges 404 are connected to a crown 406 on the side opposite to the side connecting the neck 402, and the crown defines the distal end 400C. In addition, the frame 400 defines a lumen 430 that is coaxial with the longitudinal axis 60 (see Figure 13 ).

[0109] In some examples, the frame 400 is integral (i.e., a monolithic structure) and is formed of a flexible, elastic material (e.g., nitinol). The frame 400 can be formed from a flat or cylindrical tube stock using any suitable method. For example, the frame 400 can be formed by cutting, laser cutting, stamping, a combination thereof, etc., such that the frame is separated to form the ridges 404 and define the neck 402 and the crown 406. Alternatively or in addition, the frame 400 can be shaped such that a portion 404B2 of the ridge 404 extends from a joint portion between two sheets 404A, 404B of the ridge 404. Due to the elastic properties of the material, the shape of the frame 400 can be set to be biased to the expanded configuration as Figure 11A shown or to the collapsed configuration as Figure 11B shown.

[0110] In addition to the above, each ridge 404 also includes a straight portion 404A connected to the neck 402 and a second straight portion 404B connected to the first straight portion 404A, and the first straight portion serves as a joint for the intermediate opposite ends of the second straight portion. In the collapsed configuration, each connected first straight portion 404A and second straight portion 404B are oriented at a first angle relative to each other. In the expanded configuration, each connected first straight portion 404A and second straight portion 404B are oriented at a second angle relative to each other, and the second angle is less than the first angle (e.g., as Figure 11A compared with Figure 11BFor comparison). In the collapsed configuration, each ridge 404 extends along the longitudinal axis 60 (but not necessarily exactly parallel to the longitudinal axis). The width of each ridge 404 can be adjusted to vary the stiffness of the frame 400.

[0111] Turning now Figure 11B , to form the distal end 28 of the probe 14, the ridge frame 300 is connected to a flexible elongate shaft 80 that includes a shaft lumen 82. A flexible membrane 410 is also connected to the ridge frame 400 on a portion 404B1 of the second straight portion 404B of the ridge 104 that faces distally (relative to the proximal end of the probe 14) in the expanded configuration and faces outwardly in the collapsed configuration. When connected to the ridge 404, the membrane 410 and the ridge 404 generally resemble the form of an umbrella and are approximately conical. In some examples, the flexible membrane 410 is made of a biocompatible elastomeric material.

[0112] In addition, a plurality of electrodes 26 are formed on the distally facing portion of the membrane 420, such that in combination with the conical shape of the membrane in the expanded configuration, maximizes contact with the affected area of the heart 12 (discussed in more detail below). The electrodes 26 shown in this example can be made, for example, using a conductive epoxy, using a flexible printed circuit board (PCB), or by a vapor deposition layer.

[0113] Figure 12 is a schematic illustration of a cross-sectional view of the distal end 28 of Figure 11C shown in the collapsed configuration and proximal to the ostium 34 of the pulmonary vein PV. Figure 13 is a schematic illustration of a cross-sectional view of the distal end 28 of Figure 11C shown in the expanded configuration and pressed against the ostium 34 of the pulmonary vein PV.

[0114] Specifically referring to Figures 12 to 13 , in addition to the medical probe 14, the system according to the disclosed technology also includes a guidewire 70 and an actuator 92 (presented as a push / pull rod in this example, but can take other forms, such as a pull wire). The guidewire 70 is guided through the frame lumen 430 of the distal end 28, through the lumen 82 of the elongate shaft 80, to the proximal end of the medical probe (which includes, for example, a handle). The push rod is connected to the crown 406 or the neck 402 of the ridge frame 400 and will be described in more detail below.

[0115] By way of example, the following description assumes that a target region (such as the ostium 34 of the pulmonary vein PV) will be ablated. Of course, it should be understood that the presently described technology can be used to ablate and / or map other regions of the heart 12.

[0116] In an initial step, physician 24 inserts the distal end 28 and the guide wire 70 into the subject, and the pusher 92 is positioned to force the ridge frame 400 into a collapsed configuration. For example, when connected to the crown 406, a distally-directed force on the pusher 92 (i.e., relative to Figure 12 right) keeps the frame 400 in a collapsed configuration, while when connected to the neck 402, the neck 402 can be made slidable such that a proximally-directed force on the pusher 92 (i.e., relative to Figure 13 left, as indicated by the direction arrow) keeps the frame 400 in a collapsed configuration. The guide wire 70 is then navigated into the heart 12. In this example, within the heart 12, the guide wire 70 is navigated into the pulmonary vein PV.

[0117] After the guide wire 70 has been guided into the pulmonary vein PV, the ridge frame 400, the elongate shaft 80, and the pusher 92 slide along the guide wire 70 until they are positioned near the ostium 34. Once the distal end 28 of the probe 14 is properly positioned, the pusher 92 (when connected to the crown 406) can be actuated in the proximal direction (relative to Figure 13 the direction shown to the left, as described above, and as indicated by the direction arrow). This actuation exposes the distal end 28, which causes the ridges 304 to bend outward to the expanded configuration. Once in the expanded configuration, the conical form of the membrane 410, including the electrodes 26, is optimized to maximize the contact area when pressed against the ostium 34, as Figure 13 shown.

[0118] In the ablation step, physician 24 operates the processor 55 and the ablation energy generator 50 to supply current to the electrodes 26 on the membrane 410. If there are two or more electrodes 26, the current provided can be bipolar, i.e., the current can flow between the electrodes 26 to deliver ablation energy to the tissue. Alternatively, the ablation energy provided can be monopolar, i.e., the current can be applied between one of the electrodes 26 and a return electrode connected to the generator 50. The return electrode can be disposed outside the patient 23. For example, the return electrode can include a patch (e.g., patch 38, etc.) coupled to the patient's body.

[0119] In some examples, an RF sinusoidal (alternating current) current is provided to the electrodes 26 such that RF ablation of the tissue is performed. Alternatively, a pulsed current (e.g., direct current or alternating current) can be provided to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is provided to perform PFA, monopolar ablation energy can be provided by the current flowing between the electrodes 26 on the ridge 204 and the electrode patch 38 or patch. Additionally, bipolar ablation energy can be supplied by the current flowing between the electrodes 26 themselves and / or another catheter within another part of the heart 12.

[0120] Depending on the placement and arrangement of the electrode 26 on the membrane 410, a substantially complete 360-degree ablation zone can be achieved around the orifice 34 to provide pulmonary vein isolation. The electrode 26 can be therapeutically operative, for example, for ablation of the orifice, where each electrode ablates a predetermined region of the circumference around the orifice 34 to isolate the pulmonary vein, without the need to reposition the distal tip 28 one or more times during the treatment.

[0121] Optionally, the electrode 26 can also be used to assist in positioning the distal tip 28 and / or sensing anatomical signals at the orifice 34. For example, the position of the electrode 26 can be verified by the current tracking module of the PIU 30 using the impedance and / or current between the electrode 26 and the patch 38. Additionally, the position of the electrode can be verified by fluoroscopy. Once the electrode 26 is properly positioned in contact with the orifice 34, the electrode 26 generates a potential gradient signal in response to the sensed electrical potential, also referred to herein as an electrical signal. In some examples, the sensed electrical signal indicates at least one characteristic of the anatomical signal, such as the direction and propagation speed of the wavefront caused by the anatomical signal (such as an electrocardiogram (ECG) signal in the heart 12).

[0122] After ablation and / or mapping is complete, the physician 24 can slightly retract the distal tip 28 from the orifice 34 and slide the pusher 92 distally to cause the ridge 404 to bend from the expanded configuration to the collapsed configuration. Once the ridge 404 is collapsed, the guide sheath 90, the medical probe 14, and the guide wire 70 can be withdrawn from the patient's body. Of course, while the pusher 92 has been described as the device for causing the ridge frame 400 to expand and collapse, it should be understood that other forms for actuating the ridge frame 400 between the expanded configuration and the collapsed configuration (and vice versa) can be employed without departing from the spirit and scope of the present disclosure.

[0123] The disclosed techniques herein can be further understood in accordance with the following clauses:

[0124] Clause 1. A distal tip of a medical probe, the distal tip including a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along a longitudinal axis, the ridge frame including: a neck extending from the proximal end; and a plurality of ridges connected to the neck and extending along the intermediate portion to the distal end, the ridges being movable between the following configurations: a collapsed configuration, in which the ridges extend along the longitudinal axis; and an expanded configuration, in which each ridge includes a bent portion that bends away from the longitudinal axis and a planar portion extending from the bent portion to the distal end, each planar portion extending in a plane substantially orthogonal to the longitudinal axis.

[0125] Clause 2. The distal end according to Clause 1, each ridge extends substantially parallel to the longitudinal axis in the collapsed configuration.

[0126] Clause 3. The distal end according to any one of Clauses 1 to 2, the ridge frame defines a lumen passing through the ridge frame.

[0127] Clause 4. The distal end according to any one of Clauses 1 to 3, the ridge frame comprises a shape memory alloy material.

[0128] Clause 5. The distal end according to any one of Clauses 1 to 4, further comprising a plurality of electrodes connected to the ridge frame.

[0129] Clause 6. The distal end according to Clause 5, each electrode comprises at least one of conductive epoxy resin, flexible printed circuit board, vapor deposition layer or annular electrode.

[0130] Clause 7. The distal end according to any one of Clauses 1 to 4, each planar portion terminates at the distal end.

[0131] Clause 8. The distal end according to Clause 7, further comprising a flexible membrane connected to the planar portion of the ridge, the flexible membrane comprising a first portion extending along the plane in the expanded configuration.

[0132] Clause 9. The distal end according to Clause 8, the flexible membrane is further connected to the arcuate portion of the ridge.

[0133] Clause 10. The distal end according to any one of Clauses 8 to 9, further comprising one or more electrodes connected to the first portion of the flexible membrane.

[0134] Clause 11. The distal end according to Clause 7, further comprising a plurality of flexible membranes, each flexible membrane surrounding a corresponding ridge.

[0135] Clause 12. The distal end according to Clause 11, further comprising one or more annular electrodes connected to each ridge.

[0136] Clause 13. The distal end according to any one of Clauses 1 to 4, the ridge frame comprises a plurality of rods, each rod comprising: a first end; a second end; and a ring portion connecting the first end and the second end, the first end and the second end of the rod together form the neck, and the ring portion forms the ridge.

[0137] Clause 14. The distal end according to Clause 13, further comprising a plurality of flexible membranes, each flexible membrane surrounding a corresponding ridge.

[0138] Clause 15. The distal end according to Clause 14 further includes one or more annular electrodes connected to each ridge.

[0139] Clause 16. A distal end of a medical probe, the distal end including a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along a longitudinal axis, the ridge frame including: a neck extending from the proximal end; a plurality of ridges extending along the intermediate portion, each ridge including: a first straight portion connected to the neck; and a second straight portion including a first end and a second end, the first straight portion being connected to the second straight portion at a joint intermediate the first end and the second end; a crown connected to the second straight portion and extending to the distal end, the ridge frame being movable between the following configurations: a collapsed configuration in which each connected first straight portion and second straight portion are oriented at a first angle relative to each other; and an expanded configuration in which each connected first straight portion and second straight portion are oriented at a second angle relative to each other, the second angle being less than the first angle.

[0140] Clause 17. The distal end according to Clause 16 further includes a flexible membrane connected to the second straight portion.

[0141] Clause 18. The distal end according to Clause 17 further includes one or more electrodes connected to the flexible membrane.

[0142] Clause 19. For the distal end according to Clause 18, each electrode includes at least one of conductive epoxy resin, flexible printed circuit board, or vapor deposition layer.

[0143] Clause 20. For the distal end according to any one of Clauses 17 to 19, the flexible membrane includes a tapered shape in the expanded configuration of the ridge frame.

[0144] Clause 21. For the distal end according to any one of Clauses 16 to 20, each ridge extends along the longitudinal axis in the collapsed configuration.

[0145] Clause 22. For the distal end according to any one of Clauses 16 to 21, the ridge frame defines a lumen passing through the ridge frame.

[0146] Clause 23. For the distal end according to any one of Clauses 16 to 22, the ridge frame comprises a shape memory alloy material.

[0147] Clause 24. A system includes: a medical probe, the medical probe including: a slender shaft extending along a longitudinal axis; and a distal end of the medical probe, the distal end including a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along the longitudinal axis, the ridge frame including: a neck extending from the proximal end; and a plurality of ridges connected to the neck and extending along the intermediate portion to the distal end, the ridges being movable between the following configurations: a collapsed configuration in which the ridges extend along the longitudinal axis; and an expanded configuration in which each ridge includes a curved portion bent away from the longitudinal axis and a planar portion extending from the curved portion to the distal end, each planar portion extending in a plane substantially orthogonal to the longitudinal axis; a guide wire extending through the slender shaft and the distal end; and a guiding sheath capable of sliding relative to the distal end to move the ridges between the collapsed configuration and the expanded configuration.

[0148] Clause 25. The system according to Clause 24, wherein the slender shaft defines a lumen and the ridge frame defines a lumen, and the guide wire extends through the lumens.

[0149] Clause 26. The system according to any one of Clauses 24 to 25, further including a plurality of electrodes connected to the ridge frame.

[0150] Clause 27. The system according to any one of Clauses 24 to 27, wherein the ridges are biased to the expanded configuration.

[0151] Clause 28. A system includes: a medical probe, the medical probe including: a slender shaft extending along a longitudinal axis; and a distal end including a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along the longitudinal axis, the ridge frame including: a neck extending from the proximal end; a plurality of ridges extending along the intermediate portion, each ridge including: a first straight portion connected to the neck; a second straight portion including a first end and a second end, the first straight portion being connected to the second straight portion at a joint intermediate the first end and the second end; and a crown connected to the second straight portion and extending to the distal end, the ridge frame being movable between: a collapsed configuration in which each connected first straight portion and second straight portion are oriented at a first angle relative to each other; and an expanded configuration in which each connected first straight portion and second straight portion are oriented at a second angle relative to each other, the second angle being less than the first angle; a guide wire extending through the slender shaft and the distal end; and a rod or wire connected to one of the neck or the crown and operable to move the ridge frame between the collapsed configuration and the expanded configuration.

[0152] Clause 29. The system according to Clause 28, wherein the slender shaft defines a lumen and the ridge frame defines a lumen, and the guide wire extends through the lumens.

[0153] Clause 30. The system according to any one of Clauses 28 to 29, further including a plurality of electrodes connected to the ridge frame.

[0154] Clause 31. The system according to any one of Clauses 28 to 30, wherein the ridge is biased to the expanded configuration or the collapsed configuration.

[0155] Clause 32. A method of manufacturing a distal end of a medical probe includes: cutting a tube extending along a longitudinal axis to define a neck and a plurality of ridges; and shaping the ridges such that each ridge includes a curved portion bent away from the longitudinal axis and a planar portion extending from the curved portion, each planar portion extending in a plane generally orthogonal to the longitudinal axis.

[0156] Clause 33. A method of manufacturing a distal end of a medical probe, comprising: shaping a plurality of rods such that each rod includes: a first end portion extending along a longitudinal axis; a first curved portion extending from the first end portion and curving away from the longitudinal axis; a planar portion extending from the curved portion forming a partial annular shape, the planar portion extending in a plane substantially orthogonal to the longitudinal axis; a second curved portion extending from the planar portion and curving toward the longitudinal axis; and a second end portion extending from the second curved portion and along the longitudinal axis; and joining the rods together such that the first end portion and the second end portion define a lumen.

[0157] Clause 34. A method of using a medical probe, the medical probe including a distal end having a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along a longitudinal axis, the ridge frame including a neck extending from the proximal end and a plurality of ridges connected to the neck and extending along the intermediate portion to the distal end, a plurality of electrodes being connected to the ridge frame, the method comprising: moving the ridges from a collapsed configuration, in which the ridges extend along the longitudinal axis, to an expanded configuration, in which each ridge includes a curved portion curving away from the longitudinal axis and a planar portion extending from the curved portion to the distal end, each planar portion extending in a plane substantially orthogonal to the longitudinal axis; and positioning the planar portion against a pulmonary vein opening such that the electrodes are placed in contact with the pulmonary vein opening.

[0158] Clause 35. A method of using a medical probe, the medical probe including a distal end having a ridge frame having a proximal end, an intermediate portion, and a distal end and extending along a longitudinal axis, the ridge frame including a neck extending from the proximal end, a plurality of ridges extending along the intermediate portion, and a crown connected to the second straight portion and extending to the distal end, each ridge including a first straight portion connected to the neck and a second straight portion including a first end and a second end, the first straight portion being connected to the second straight portion at a joint intermediate the first end and the second end, the method comprising: moving the ridge frame from a collapsed configuration, in which each connected first straight portion and second straight portion are oriented at a first angle relative to each other, to an expanded configuration, in which each connected first straight portion and second straight portion are oriented at a second angle relative to each other, the second angle being less than the first angle; and positioning the second straight portion against a pulmonary vein opening such that the electrodes are placed in contact with the pulmonary vein opening.

[0159] The above embodiments are cited by way of example, and the technology disclosed by the present invention is not limited by the content specifically shown and described above. On the contrary, the scope of the technology disclosed by the present invention includes combinations and sub - combinations of the various features described above, as well as their variations and modifications, which will occur to those skilled in the art upon reading the above description and which are not disclosed in the prior art.

Claims

1. A distal tip of a medical probe, the distal tip comprising a spine frame having a proximal end, a middle portion and a distal end and extending along a longitudinal axis, the spine frame comprising: a neck extending from the proximal end; and a plurality of ridges connected to the neck and extending along the intermediate portion to the distal end, the ridges being movable between the following configurations: a collapsed configuration, wherein the ridge extends along the longitudinal axis; and An expanded configuration wherein each ridge includes a curved portion that curves away from the longitudinal axis and a planar portion that extends from the curved portion to the distal end, each planar portion extending along a plane that is generally orthogonal to the longitudinal axis.

2. The distal tip of claim 1, each ridge extending generally parallel to the longitudinal axis in the collapsed configuration.

3. The distal tip of claim 1, the spine frame defining a lumen therethrough.

4. The distal tip of claim 1 further comprising a plurality of electrodes connected to the spine frame.

5. The distal tip of any one of claims 1, each planar portion terminating at the distal end.

6. The distal tip of claim 5, further comprising a flexible membrane connected to the planar portion of the ridge, the flexible membrane including a first portion extending along the plane in the expanded configuration.

7. The distal tip of claim 6, the flexible membrane further connected to the arcuate portion of the spine.

8. The distal tip of claim 6, further comprising one or more electrodes connected to the first portion of the flexible membrane.

9. The distal tip of claim 5, further comprising a plurality of flexible membranes, each flexible membrane surrounding a respective ridge.

10. The distal tip of claim 9, further comprising one or more ring electrodes connected to each ridge.

11. The distal tip of claim 1 , the spine frame comprising a plurality of rods, each rod comprising: a first end portion; a second end portion; and a ring portion connecting the first end portion and the second end portion, The first end and the second end of the rod together form the neck, and The ring portion forms the ridge.

12. The distal tip of claim 11, further comprising a plurality of flexible membranes, each flexible membrane surrounding a respective ridge.

13. The distal tip of claim 12, further comprising one or more ring electrodes connected to each ridge.

14. A distal tip of a medical probe, the distal tip comprising a spine frame having a proximal end, a middle portion, and a distal end and extending along a longitudinal axis, the spine frame comprising: a neck extending from the proximal end; a plurality of ridges extending along the intermediate portion, each ridge comprising: a first straight portion connected to the neck; and a second straight portion, the second straight portion comprising a first end and a second end, the first straight portion being connected to the second straight portion at a joint intermediate the first end and the second end; a crown portion connected to the second straight portion and extending to the distal end, The spine frame is capable of moving between the following configurations: a collapsed configuration, wherein each connected first and second straight portions are oriented at a first angle relative to each other; and An expanded configuration wherein each connected first and second straight portions are oriented at a second angle relative to each other, the second angle being less than the first angle.

15. The distal tip of claim 14, further comprising a flexible membrane connected to the second straight portion.

16. The distal tip of claim 15, further comprising one or more electrodes connected to the flexible membrane.

17. The distal tip of claim 15, said flexible membrane comprising a tapered shape in said expanded configuration of said spine frame.

18. The distal tip of claim 14, each ridge extending along the longitudinal axis in the collapsed configuration.

19. The distal tip of claim 14, the spine frame defining a lumen therethrough.

20. A system comprising: A medical probe, comprising: an elongated shaft extending along a longitudinal axis; and A distal tip of a medical probe, the distal tip comprising a spine frame having a proximal end, a middle portion and a distal end and extending along a longitudinal axis, the spine frame comprising: a neck extending from the proximal end; and a plurality of ridges connected to the neck and extending along the intermediate portion to the distal end, the ridges being movable between the following configurations: a collapsed configuration, wherein the ridge extends along the longitudinal axis; and an expanded configuration, wherein each ridge includes a curved portion that curves away from the longitudinal axis and a planar portion that extends from the curved portion to the distal end, each planar portion extending along a plane that is generally orthogonal to the longitudinal axis; a guidewire extending through the elongated shaft and the distal tip; and An introducer sheath is slidable relative to the distal tip to move the spine between the collapsed configuration and the expanded configuration.

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