Medical probe with spines for pulmonary vein isolation

Abstract

To provide an improved end effector for a medical probe.SOLUTION: A disclosed technique includes a distal tip of a medical probe. The distal tip includes a neck and spines that extend along a longitudinal axis. The neck extends from a proximal end of the distal tip. The spines are connected to the neck and extend from an intermediate section of the distal tip to a distal end of the distal tip. The spines are movable between a collapsed configuration and an expanded configuration. In the collapsed configuration, the spines extend along the longitudinal axis. In the expanded configuration, each spine includes a curved section that bends away from the longitudinal axis and a planar section extending from the curved section to the distal end. Further, in the expanded configuration, each planar section extends along a plane that is approximately orthogonal to the longitudinal axis.SELECTED DRAWING: Figure 2B

Description

Technical Field

[0001] The present technology generally relates to medical devices, particularly medical probes having electrodes, and more particularly to medical probes suitable for use in tissue mapping and / or ablation, but is not limited thereto.

Background Art

[0002] Cardiac arrhythmias such as atrial fibrillation (AF) occur when regions of cardiac tissue conduct electrical signals abnormally to adjacent tissue. This disrupts the normal cardiac cycle and causes asynchronous rhythms. Certain procedures that exist for treating arrhythmias include surgically destroying the source of signals that cause the arrhythmia and destroying the conduction pathways of such signals. By selectively ablating cardiac tissue by applying energy via a catheter, it is sometimes possible to stop or alter the propagation of unwanted electrical signals from one part of the heart to another.

[0003] Many current ablation approaches 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, burning, steam pops, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulas.

[0004] Cryoablation is an alternative approach to RF ablation that generally reduces the thermal risks associated with RF ablation. However, operating a cryoablation device and selectively applying cryoablation is generally more difficult compared to RF ablation, and thus cryoablation may not be feasible in certain anatomical shapes that can be reached by an electrical ablation device.

[0005] Some ablation approaches use irreversible electroporation (IRE) to ablate cardiac tissue using a non-thermal ablation method. IRE delivers high-voltage short pulses to tissue, causing irreversible permeabilization of cell membranes. Delivery of IRE energy to tissue using multi-electrode probes has been previously proposed in the patent literature. Examples of systems and devices configured for IRE ablation are disclosed in U.S. Patent Application Publication Nos. 2021 / 0169550 (A1), 2021 / 0169567 (A1), 2021 / 0169568 (A1), 2021 / 0161592 (A1), 2021 / 0196372 (A1), 2021 / 0177503 (A1), and 2021 / 0186604 (A1), each of which is incorporated herein by reference.

Summary of the Invention

Problems to be Solved by the Invention

[0006] In current practice, the effectiveness of IRE energy delivery depends on the skills 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, an improved end effector for medical probes to address these problems is needed.

Means for Solving the Problems

[0007] Provided is a distal tip of a medical probe according to the disclosed technology. The distal tip has a proximal end, an intermediate section, and a distal end, and includes a spine framework extending along a longitudinal axis. The spine framework includes a neck and a plurality of spines. The neck extends from the proximal end. The spines are connected to the neck and extend along the intermediate section to the distal end. The spines are movable between (1) a collapsed configuration in which the spines extend along the longitudinal axis and (2) an expanded configuration in which each spine includes a curved section that bends away from the longitudinal axis and a planar section extending from the curved section to the distal end, and each planar section extends along a plane substantially orthogonal to the longitudinal axis.

[0008] Further provided is a distal tip of a medical probe according to the disclosed technology. The distal tip has a proximal end, an intermediate section, and a distal end, and includes a spine framework extending along a longitudinal axis. The spine framework includes a neck, a plurality of spines, and a crown. The neck extends from the proximal end. The spines extend along the intermediate section. Each spine includes (1) a first straight section connected to the neck and (2) a second straight section having a first end and a second end. The first straight section is connected to the second straight section at a junction intermediate the first end and the second end. The crown is connected to the second straight section and extends to the distal end. The spine framework is movable between (1) a collapsed configuration in which each connected first straight section and second straight section are oriented at a first angle with respect to each other and (2) an expanded configuration in which each connected first straight section and second straight section are oriented at a second angle with respect to each other, and the second angle is smaller than the first angle.

[0009] The disclosed technology further provides a system including a medical probe, a guide wire, and a guide sheath. The medical probe includes an elongated shaft and a distal tip. The elongated shaft extends along a longitudinal axis. The distal tip has a proximal end, an intermediate section, and a distal end, and includes a spine framework extending along the longitudinal axis. The spine framework includes a neck and a plurality of spines. The neck extends from the proximal end. The spines are connected to the neck and extend from the intermediate section to the distal end. The spines are movable between (1) a collapsed configuration in which the spines extend along the longitudinal axis and (2) an expanded configuration in which each spine includes a curved section that bends away from the longitudinal axis and a planar section extending from the curved section to the distal end, with each planar section extending along a plane substantially orthogonal to the longitudinal axis. The guide wire extends through the elongated shaft and the distal tip. The guide sheath is slidable relative to the distal tip to move the spines between the collapsed configuration and the expanded configuration.

[0010] The disclosed technology further provides a system including a medical probe, a guidewire, and a rod or wire. The medical probe includes an elongated shaft and a distal tip. The elongated shaft extends along a longitudinal axis. The distal tip has a proximal end, an intermediate section, and a distal end, and includes a spine framework that extends along the longitudinal axis. The spine framework includes a neck, a plurality of spines, a first straight section, a second straight section, and a crown. The neck extends from the proximal end. The spines extend along the intermediate section. Each spine includes (1) a first straight section connected to the neck and (2) a second straight section having a first end and a second end, and the first straight section is connected to the second straight section at a junction intermediate the first end and the second end. The crown is connected to the second straight section and extends to the distal end. The spine framework is movable between (1) a collapsed configuration in which each connected first straight section and second straight section are oriented at a first angle with respect to each other and (2) an expanded configuration in which each connected first straight section and second straight section are oriented at a second angle with respect to each other, the second angle being smaller than the first angle. The guidewire extends through the elongated shaft and the distal tip. The rod or wire is connected to one of the neck or the crown and is operable to move the spine framework between the collapsed configuration and the expanded configuration.

[0011] The disclosed technology further provides a method of fabricating a distal dip of a medical probe. The method includes cutting a tube that extends along a longitudinal axis to define a neck and a plurality of spines. The method includes shaping the spines such that each spine includes a curved section that curves away from the longitudinal axis and a planar section that extends from the curved section, and each planar section extends along a plane that is substantially orthogonal to the longitudinal axis.

[0012] The disclosed technology further provides a method of fabricating a distal tip of a medical probe. The method includes shaping a plurality of rods such that each rod comprises: (1) a first end extending along a longitudinal axis; (2) a first curved section extending from the first end and curving away from the longitudinal axis; (3) a planar section extending from the curved section and forming a partial loop shape, the planar section extending along a plane substantially orthogonal to the longitudinal axis; (4) a second curved section extending from the planar section and curving toward the longitudinal axis; and (5) a second end extending from the second curved section and along the longitudinal axis. The method includes connecting the rods together such that the first end and the second end define a lumen.

[0013] The disclosed technology further provides a method of using a medical probe. The medical probe has a proximal end, an intermediate section, and a distal end, and includes a distal tip portion having a spine framework extending along a longitudinal axis. The spine framework includes a neck extending from the proximal end and a plurality of spines connected to the neck and extending along the intermediate section to the distal end. A plurality of electrodes are connected to the spine framework. The method includes moving the spines from: (1) a collapsed configuration in which the spines extend along the longitudinal axis; to (2) an expanded configuration in which each spine comprises a curved section curving away from the longitudinal axis and a planar section extending from the curved section to the distal end, each planar section extending along a plane substantially orthogonal to the longitudinal axis. The method includes positioning the planar section in contact with a pulmonary vein ostium such that the electrodes are disposed in contact with the pulmonary vein ostium.

[0014] The disclosed technology further provides a method of using a medical probe. The medical probe includes a distal tip having a spine framework extending along a longitudinal axis and having a proximal end, an intermediate section, and a distal end. The spine framework includes a neck extending from the proximal end, a plurality of spines extending along the intermediate section, and a crown connected to a second straight section and extending to the distal end. Each spine includes a first straight section connected to the neck and a second straight section having a first end and a second end. The first straight section is connected to the second straight section at a junction intermediate the first end and the second end. The method includes moving the spine framework from (1) a collapsed configuration in which each connected first straight section and second straight section are oriented at a first angle relative to each other to (2) an expanded configuration in which each connected first straight section and second straight section are oriented at a second angle relative to each other, the second angle being less than the first angle. The method includes positioning the second straight section in contact with the pulmonary vein ostium such that the electrode is disposed in contact with the pulmonary vein ostium.

Brief Description of the Drawings

[0015]

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DETAILED DESCRIPTION OF THE INVENTION

[0016] The following detailed description should be read with reference to the drawings, and like elements in different drawings are numbered the same. The drawings are not necessarily to scale and show selected embodiments and are not intended to limit the scope of the present disclosure. The detailed description is illustrative, not limiting, and exemplifies the principles of the disclosed technology. This description enables those skilled in the art to make and use the disclosed technology and describes some embodiments, adaptations, variations, alternatives, and uses of the disclosed technology, including what is currently considered to be the best mode for practicing the disclosed technology.

[0017] As used herein, the terms "about," "substantially," or "generally" with respect to any numerical value or range indicate a suitable dimensional tolerance that allows a component or collection to function for the intended purpose described herein. More specifically, "about" or "substantially" can refer to a range of values that are ±20% of the recited value. For example, "about 90%" can refer to a range of values from 71% to 110%. Additionally, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject, and the use of the technology of interest in a human patient represents a preferred embodiment, but is not intended to limit the system or method to human use. Similarly, the term "proximal" indicates the location closer to the operator or physician, while "distal" indicates the location farther from the operator or physician.

[0018] As discussed herein, the vasculature of a "patient," "host," "user," and "subject" can be that of a human or any animal. It should be understood that the animal can be of any of a variety of applicable types, including, but not limited to, mammals, veterinary animals, domestic animals, or pet animals. As an example, the animal can be an experimental animal (e.g., rat, dog, pig, monkey, etc.) specifically selected to have certain properties similar to humans. It should be understood that the subject can be, for example, any applicable human patient.

[0019] As discussed herein, an "operator" can include a physician, surgeon, technician, scientist, or any other individual or delivery device associated with the delivery of a multi-electrode catheter for the treatment of drug-refractory atrial fibrillation to a subject.

[0020] As discussed herein, the term "ablating" or "ablation," when referring to the devices and corresponding systems of the present disclosure, refers throughout the present disclosure to components and structural features configured to reduce or prevent the generation of irregular cardiac signals within cells by utilizing non-thermal energy such as irreversible electroporation (IRE), which is interchangeably referred to as pulsed electric field (PEF) and pulsed field ablation (PFA) throughout the present disclosure. When referring to the devices and corresponding systems of the present disclosure, ablating or ablation is used throughout the present disclosure with reference to non-thermal ablation of cardiac tissue in certain conditions, including but not limited to arrhythmias, atrial fibrillation ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The term "ablating" or "ablation" also includes known methods, devices, and systems for achieving various forms of body tissue ablation, as would be understood by one of ordinary skill in the art.

[0021] As discussed herein, the terms "bipolar" and "unipolar," when used to refer to ablation schemes, describe different ablation schemes with respect to current paths and electric field distributions. "Bipolar" refers to an ablation scheme that utilizes the current path between two electrodes both positioned at the treatment site. The current density and electric flux density are typically approximately equal at each of the two electrodes. "Unipolar" refers to an ablation scheme that utilizes the current path between two electrodes, where one electrode having a high current density and high electric flux density is positioned at the treatment site and a second electrode having a relatively low current density and lower electric flux density is positioned remotely from the treatment site.

[0022] As contemplated herein, the terms "tubular" and "tube" are to be construed broadly and are not limited to a straight cylindrical structure, or a structure having a cross-section that is strictly circular, or a structure having a uniform cross-section throughout its length. For example, a tubular / shaft structure is generally illustrated as a substantially straight cylindrical structure. However, a tubular / shaft structure may have a tapered or curved outer surface without departing from the scope of the present disclosure.

[0023] The present disclosure relates to a system, method, or use and device for IRE ablation of cardiac tissue for treating cardiac arrhythmias. Ablation energy is typically delivered to cardiac tissue by a distal portion of a catheter that can deliver ablation energy along the tissue to be ablated. Some exemplary catheters include a three-dimensional structure at the distal portion and are configured to manage ablation energy from various electrodes positioned on the three-dimensional structure. Ablation procedures incorporating such exemplary catheters can be visualized using fluoroscopy.

[0024] To improve a failing heart, ablation of heart tissue applying thermal techniques such as radiofrequency (RF) energy and cryoablation is a well-known procedure. Typically, to successfully ablate using thermal techniques, it is necessary to measure the electrocardiogram at various locations in the myocardium. In addition, temperature measurements during ablation provide data that enables the effectiveness of ablation. Usually, in ablation procedures using thermal techniques, electrode potential and temperature are measured before, during, and after the actual ablation. The RF approach can have risks leading to tissue carbonization, burning, steam pop, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistula. Cryoablation is an alternative approach to RF ablation that can reduce some of the thermal risks associated with RF ablation. However, operating a cryoablation device and selectively applying cryoablation is generally more difficult compared to RF ablation. Thus, cryoablation is not feasible in certain anatomical shapes that can be reached by an electrical ablation device.

[0025] The present disclosure may include electrodes configured for irreversible electroporation (IRE), RF ablation, and / or cryoablation. IRE may be interchangeably referred to as pulsed electric field (PEF) ablation and pulsed field ablation (PFA) throughout the present disclosure. The IRE contemplated in the present disclosure is a non-thermal cell death technique that can be used for ablation of atrial arrhythmias. To ablate using IRE / PEF, a biphasic voltage pulse is applied to disrupt the cellular structure of the myocardium. The biphasic pulse is a non-sinusoidal waveform and can be tailored to target cells based on the electrophysiology of the cells. In contrast, to ablate using RF, a sinusoidal voltage waveform is applied to generate heat in the treatment area and indiscriminately heat all cells within the treatment area. Thus, IRE has the ability to spare adjacent thermosensitive structures or tissues, which would be beneficial in reducing the possible complications known in ablation modalities or isolation modalities. Additionally or alternatively, monophasic pulses can be utilized.

[0026] Electroporation can be induced by applying a pulsed electric field to biological cells to cause reversible (temporary) or irreversible (permanent) formation of pores within the cell membrane. Cells have a transmembrane electrostatic potential that increases beyond the resting potential upon application of the pulsed electric field. The transmembrane electrostatic potential remains below the threshold potential, but electroporation is reversible, meaning that the pores can close when the applied pulsed electric field is removed and the cells can self-repair and survive. When the transmembrane electrostatic potential increases beyond the threshold potential, electroporation is irreversible and the cells become permanently permeable. As a result, the cells die due to loss of homeostasis and typically die 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 bone has a threshold potential of 3000 V / cm. These differences in threshold potential allow IRE to selectively target tissues based on the threshold potential.

[0027] The techniques of the present disclosure include systems and methods for applying an electrical signal from a catheter electrode positioned in the vicinity of myocardial tissue to generate ablation energy for ablating the myocardial tissue. In some examples, the systems and methods can be effective to ablate target tissue by inducing irreversible electroporation. In some examples, the present systems and methods can be effective to induce reversible electroporation as part of a diagnostic procedure. Reversible electroporation occurs when the electricity applied at the electrode is below the electric field threshold of the target tissue, which allows the cells to repair. Reversible electroporation does not kill the cells but allows the physician to see the effect of reversible electroporation on the electrical activation signal in the vicinity of the target location. Exemplary systems and methods for reversible electroporation are disclosed in U.S. Patent Application Publication No. 2021 / 0162210, which is incorporated herein by reference in its entirety.

[0028] The effectiveness of a pulsed electric field, and of a pulsed electric field that induces reversible electroporation and / or irreversible electroporation, can be affected by the physical parameters of the system and the biphasic pulse parameters of the electrical signal. The physical parameters can include electrode contact area, electrode spacing, electrode shape, and the like. The examples presented herein generally include physical parameters adapted to effectively induce reversible and / or irreversible electroporation. The biphasic pulse parameters of the electrical signal can include voltage amplitude, pulse duration, pulse phase delay, inter-pulse delay, total application time, delivered energy, and the like. In some examples, the parameters of the electrical signal can be adjusted to induce both reversible electroporation and irreversible electroporation when the same physical parameters are provided. Examples of various systems and methods of ablation that include IRE are presented in U.S. Patent Application Publication Nos. 2021 / 0169550(A1), 2021 / 0169567(A1), 2021 / 0169568(A1), 2021 / 0161592(A1), 2021 / 0196372(A1), 2021 / 0177503(A1), and 2021 / 0186604(A1), the entireties of each of which are incorporated herein by reference.

[0029] Refer to FIG. 1 showing an exemplary catheter-based electrophysiological mapping and ablation system 10. System 10 includes a plurality of catheters that are percutaneously inserted by a physician 24 into a chamber or vascular structure of the heart 12 through the vasculature of patient 23. Typically, a delivery sheath catheter is inserted into the left atrium or right atrium near the desired location in the heart 12. Thereafter, a plurality of catheters can be inserted into the delivery sheath catheter to reach a desired location, such as the ostium 34 of the pulmonary vein (PV). The plurality of catheters may 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 to sense IEGM, such as catheter 14 (also synonymously referred to herein as probe 14), is illustrated herein. The physician 24 contacts the distal tip of catheter 14 with the heart wall to sense the target site in the heart 12. For ablation, the physician 24 similarly moves the distal end of the ablation catheter to the target site for ablation.

[0030] Catheter 14 is an exemplary catheter that includes one electrode, preferably a plurality of electrodes 26, configured to sense IEGM signals. In the embodiments described herein, the electrodes 26 can be configured to deliver ablation energy (IRE and / or RF) to tissue within the heart 12. In addition to using the electrodes 26 to deliver ablation energy, the electrodes 26 can also be used to determine the location of the end effector 100 and / or measure physiological properties such as local surface potential at each location on the tissue within the heart 12. The electrodes 26 can be biased such that a wider portion of the electrodes 26 faces outwardly from the end effector 100, whereby the electrodes 26 deliver a greater amount of electrical energy outwardly away from the end effector 100 (i.e., toward the tissue of the heart 12) than the amount of inward electrical energy directed toward the end effector 100.

[0031] Examples of materials that are ideally suitable for forming the electrode 26 include gold, platinum, and palladium (as well as their respective alloys). These materials also have high thermal conductivity, which allows a minimum amount of heat generated in the tissue (i.e., due to the ablation energy delivered to the tissue) to be conducted through the electrode to the back side of the electrode (i.e., the portion of the electrode 26 inside the spine) and then to the blood pool within the heart 12.

[0032] The catheter 14 may additionally include a position sensor embedded within or near the distal tip 28 to track the position and orientation of the 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.

[0033] The magnetic-based position sensor may operate with a location pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field within a predetermined working volume. The real-time position of the distal tip 28 of the catheter 14 can be tracked based on the magnetic field generated by the location pad 25 and sensed by the magnetic-based position sensor. Details of magnetic-based position sensing techniques are described in U.S. Patent 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.

[0034] System 10 includes one or more electrode patches 38 positioned for skin contact on patient 23 to establish location reference of location pad 25 and impedance-based tracking of electrodes 26. For impedance-based tracking, current is directed to electrodes 26 and sensed at electrode skin patches 38, whereby the location of each electrode can be triangulated via electrode patches 38. Details of impedance-based location tracking techniques are described in U.S. Patent 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.

[0035] Recorder 11 displays the electrogram 21 captured by body surface ECG electrodes 18 and the intracardiac electrogram (IEGM) captured by electrodes 26 of catheter 14. Recorder 11 may include pacing capabilities for pacing the rhythm of the heart and / or may be electrically connected to an independent pacer.

[0036] System 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more of the electrodes at the distal tip of a catheter configured to ablate. The energy generated by ablation energy generator 50 may include high-frequency (RF) energy or pulsed-field ablation (PFA) energy, including unipolar or bipolar high-voltage direct current (DC) or alternating current (AC) pulses such that they can be used to effect irreversible electroporation (IRE), or combinations thereof, but is not limited thereto.

[0037] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between a catheter, an electrophysiology device, a power source, and a workstation 55 that controls the operation of the system 10. The electrophysiology devices of the system 10 may include, for example, a plurality of catheters, location pads 25, body surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 additionally includes processing capabilities for implementing real-time calculations of catheter locations and performing ECG calculations.

[0038] The workstation 55 includes a memory, a processor unit having a memory or storage device loaded with appropriate operating software, and user interface functions. The workstation 55 may optionally (1) model the endocardial anatomical structure in three dimensions (3D) and render it for display on a display device 27 as a model or anatomical map 20, (2) display on the display device 27 a representative visual display or image of an activation sequence (or other data) compiled from the recorded electrogram 21 superimposed on the rendered anatomical map 20, (3) display the real-time locations and orientations of a plurality of catheters within the heart chamber, and (5) display on the display device 27 regions of interest such as locations where ablation energy is being applied. One commercially available product embodying the elements of the system 10 is available as the CARTO (trademark) 3 system, marketed by Biosense Webster, Inc. (31 Technology Drive, Suite 200, Irvine, CA 92618, USA).

[0039] FIG. 2A is a schematic drawing showing a perspective view of a spine framework 100 of a distal tip 28 of a medical probe 14 in a collapsed configuration. FIG. 2B is a schematic drawing showing a perspective view of the spine framework 100 in an expanded configuration. FIG. 2C is a schematic drawing showing a perspective view of the distal side of the distal tip 28 having the spine framework 100 in an expanded configuration. FIG. 2D is a schematic drawing showing a perspective view of the proximal side of the distal tip of FIG. 2C in an expanded configuration.

[0040] Referring now to FIGS. 2A and 2B, the distal tip 28 of the catheter / medical probe 14 can be defined by a spine framework 100 that extends along a longitudinal axis 60 and has a proximal end 100A, an intermediate section 100B, and a distal end 100C. The framework 100 includes a neck 102 (extending from the proximal end 100A) and a plurality of spines 104 that are connected to and extend from the neck 102 to the distal end 100C along the intermediate section 100B. Further, the framework 100 defines a lumen 130 (see FIG. 4) that is coaxial with the longitudinal axis 60.

[0041] In some examples, the framework 100 is single (i.e., monolithic). The framework 100 can be formed from a flat or cylindrical tube stock of material using any suitable method. For example, the framework 100 can be formed by cutting, laser cutting, stamping, combinations thereof, etc., such that the spines 104 are formed and the neck 102 is defined by being split.

[0042] The framework 100 includes a flexible elastic material (e.g., a shape memory alloy such as nickel-titanium, also known as nitinol), and the shape memory alloy is shaped such that, as shown in FIG. 2B, it is biased to curve outwardly into an expanded configuration. In the expanded configuration, the framework 100 resembles a lily flower. Due to the flexible and elastic nature of the material, the spine 104 can also move to a collapsed configuration (such as that shown in FIG. 2A) where the spine 104 extends along the longitudinal axis 60. In the expanded configuration, each spine 104 has a curved section 104A that curves away from the longitudinal axis 60 and a planar section 104B that extends linearly from the curved section 104A along the plane 120 and terminates at the distal end 100C of each spine 104. As seen in FIG. 2B, the plane 120 is substantially orthogonal to the longitudinal axis 60.

[0043] Referring now to FIGS. 2C and 2D, to form the distal tip 28 of the probe 14, the spine framework 100 is connected to a flexible elongate shaft 80. A flexible membrane 110 is also connected to the spine framework 100 on the sides of the spines 104 that face distally in the expanded configuration (relative to the proximal end of the probe 14) and face inwardly in the collapsed configuration. More specifically, a first portion of the flexible membrane 110 is connected to the planar section 104B of each spine 104 (so as to form a plane that is in the same plane as the plane 120), and a second portion of the membrane 110 is further connected to the arcuate section 104A of each spine (that portion of the membrane 110 resembles a curved funnel in appearance). In some examples, the flexible membrane 110 is made from a biocompatible elastomeric material.

[0044] As can be seen particularly in FIG. 2C, a plurality of electrodes 26 are formed on a surface facing distally of a flexible membrane 110 shaped to maximize contact with the affected area of the heart 12. More specifically, the electrodes 26 are formed on at least a first portion of the flexible membrane 110 such that at least a portion of each electrode 26 is disposed on or parallel to a plane 120. The electrodes 26 shown in this example can be fabricated, for example, using conductive epoxy, using a flexible printed circuit board (PCB), or by a vapor deposition layer.

[0045] FIG. 3 is a schematic drawing showing a cross-section of the distal tip 28 of FIG. 2C in a collapsed configuration and proximal to the ostium 34 of the pulmonary vein PV. FIG. 4 is a schematic drawing showing a cross-sectional view of the distal tip 28 of FIG. 2C in an expanded configuration and pressed against the ostium 34 of the pulmonary vein PV.

[0046] Specifically referring to FIGS. 3-4, in addition to the medical probe 14, the system according to the technology disclosed herein further includes a guide wire 70 and a guide sheath 90. The guide wire 70 passes through the framework lumen 130 of the distal tip 28 and through the lumen 82 of the elongated shaft 80 and is sent to the proximal end of the medical probe (including, for example, the handle). The guide sheath 90 is slidable relative to the distal tip 28 of the medical probe 14 and will be described in more detail below.

[0047] In the following description, by way of example, it is assumed that a target region (such as the ostium 34 of the pulmonary vein PV) is ablated. Of course, it will be understood that the techniques described herein may be used to ablate and / or map other regions of the heart 12.

[0048] In a first step, physician 24 inserts the distal tip 28 and guidewire 70 into the subject, and the guide sheath 90 surrounds the distal tip 28 in such a manner as to force the spine framework 100 into a collapsed configuration (from their shaped-expanded configuration). Next, the guidewire 70 is navigated within the heart 12. In this example, within the heart 12, the guidewire 70 is navigated into the pulmonary vein PV.

[0049] After the guidewire 70 is sent into the pulmonary vein PV, the spine framework 100, elongate shaft 80, and guide sheath 90 are slid along the guidewire 70 until positioned near the small aperture 34. When the distal tip 28 of the probe is properly positioned, the guide sheath 90 can be actuated in a proximal direction (leftward with respect to the orientation shown in FIG. 4 and as indicated by the direction arrow). This actuation exposes the distal tip 28 and causes the spines 104 to bend outwardly into their shaped configuration (i.e., expanded configuration). In the expanded configuration, the plane facing distally of the flexible membrane 110 including the electrodes 26 is pressed against the small aperture 34. The flat contact surfaces of the flexible membrane 110 and the electrodes 26 maximize the contact area with the small aperture 34.

[0050] In the ablation step, physician 24 operates the processor 55 and ablation energy generator 50 to supply current to the electrodes 26 of the flexible membrane 110. If two or more electrodes 26 are present, then the supplied current may be bipolar, i.e., the current may flow between the electrodes 26 to transfer ablation energy to the tissue. Alternatively, the supplied ablation energy may be unipolar, i.e., a 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 body of patient 23. For example, the return electrode may include a patch (such as patch 38 etc.) connected to the patient's body.

[0051] In some examples, a (alternating current) current, such as an RF sine wave, is supplied to electrode 26 so that RF ablation of tissue is performed. Alternatively, a pulsed current (e.g., DC or AC) may be supplied to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is supplied to perform PFA, the monopolar ablation energy can be supplied by the current flowing between electrode 26 on flexible membrane 110 and electrode patch 38 or the back patch. Further, the bipolar ablation energy can be supplied by the current flowing between electrode 26 on flexible membrane 110 itself and / or on another catheter within another part of heart 12.

[0052] Depending on the arrangement and array of electrodes 26 on flexible membrane 110, a generally complete 360-degree band of ablation around small hole 34 can be achieved to provide pulmonary vein isolation. Electrodes 26 can, for example, function therapeutically to ablate the small hole, and each electrode ablates a predetermined area around small hole 34 to isolate the pulmonary vein without the need to reposition distal tip 28 one or more times during treatment.

[0053] Optionally, electrodes 26 can also be used to assist in identifying the position of distal tip 28 and / or to sense anatomical signals at small hole 34. For example, the location of electrodes 26 can be confirmed by the current tracking module of PIU 30 using the impedance and / or current between electrodes 26 and patch 38. Additionally, the location of the electrodes can be confirmed by fluoroscopy. When electrodes 26 are properly positioned in contact with small hole 34, electrodes 26 generate a potential gradient signal, also referred to herein as an electrical signal, in response to the sensed potential. In some examples, the sensed electrical signal indicates at least one characteristic of an anatomical signal, such as the direction and propagation speed of the wavefront caused by an anatomical signal, such as an electrocardiogram (ECG) signal within heart 12.

[0054] After ablation and / or mapping is complete, the physician 24 can slightly retract the distal tip 28 from the small hole and slide the guide sheath 90 back over the distal tip 28, whereby the spine 104 bends inwardly from the expanded configuration to the collapsed configuration. When the spine 104 collapses, the guide sheath 90, the medical probe 14, and the guide wire 70 can be retracted from the patient's body. Of course, while the guide sheath 90 has been described as the device that causes the expansion and collapse of the spine framework 100, it will be understood that other forms may be employed that operate the spine framework 100 between the expanded configuration and the collapsed configuration (and vice versa) without departing from the spirit and scope of the present disclosure.

[0055] FIG. 5A is a schematic drawing showing a perspective view of another spine framework 200 of another distal tip 28 of the medical probe 14 in an expanded configuration. FIG. 5B is a schematic drawing showing a perspective view of the distal side of the distal tip 28 of the medical probe 14 in an expanded configuration having the spine framework 200 of FIG. 5A.

[0056] Referring now to FIG. 5A, another exemplary distal tip 28 of the catheter / medical probe 14 can be defined by a spine framework 200 that extends along the longitudinal axis 60 and has a proximal end, an intermediate section, and a distal end (similar to the framework 100 described above). As seen in FIG. 5A, the framework 200 can be formed similar or identical to the framework 100. The framework 200 includes a neck 202 (extending from the proximal end) and a plurality of spines 204 (extending along the intermediate section to the distal end) connected to and extending from the neck 102. Further, the framework 200 defines a lumen 230 (see FIG. 7) that is coaxial with the longitudinal axis 60.

[0057] In some examples, the framework 200 is single (i.e., monolithic). The framework 200 can be formed from a flat or cylindrical tube stock of material using any suitable method, as in the examples described above. For example, the framework 200 can be formed by cutting, laser cutting, stamping, combinations thereof, etc., such that it forms a spine 204 and is divided to define a neck 202.

[0058] The framework 200 includes a flexible elastic material (e.g., a shape memory alloy such as nickel-titanium, also known as nitinol), and the shape memory alloy is shaped such that it is biased to curve outwardly into an expanded configuration, as shown in FIG. 5B. In the expanded configuration, the framework 200 resembles a lily flower. Due to the flexible and elastic nature of the material, the spine 204 can also move to a collapsed configuration (such as shown in FIG. 6) where the spine 204 extends along the longitudinal axis 60. In the expanded configuration, each spine 204 has a curved section 204A that curves away from the longitudinal axis 60 and a planar section 204B that extends linearly from the curved section 204A along a plane 220 and terminates at the distal end of each spine 204. As seen in FIG. 5A, the plane 220 is substantially orthogonal to the longitudinal axis 60.

[0059] Referring now to FIG. 5B, to form the distal tip portion 28 of the probe 14, the spine framework 100 is connected to a flexible elongate shaft 80. Further, a plurality of electrodes 26 are formed on or around each spine 204 (to be discussed in more detail below) to maximize contact with the diseased area of the heart 12. More specifically, the electrodes 26 are formed on at least the planar portion 204B of the spine 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 fabricated using, for example, conductive epoxy, a flexible printed circuit board (PCB), a vapor deposition layer, or ring electrodes.

[0060] The flexible membrane 210 can also be attached to surround each spine 204. In some embodiments, the flexible membrane 210 is made of a biocompatible insulating material.

[0061] FIG. 6 is a schematic drawing showing a cross-sectional view of the distal tip 28 of FIG. 5B in a collapsed configuration and proximal to the small aperture 34 of the pulmonary vein PV. FIG. 7 is a schematic drawing showing a cross-sectional view of the distal tip 28 of FIG. 5B in an expanded configuration and pressed against the small aperture 34 of the pulmonary vein PV.

[0062] Referring specifically to FIGS. 6-7, in addition to the medical probe 14, the system according to the technology disclosed herein further includes a guide wire 70 and a guide sheath 90. The guide wire 70 passes through the framework lumen 230 of the distal tip 28 and through the lumen 82 of the elongate shaft 80 and is sent to the proximal end of the medical probe (including, for example, the handle). The guide sheath 90 is slidable relative to the distal tip 28 of the medical probe 14 and will be described in more detail below.

[0063] In the following description, by way of example, it is assumed that the target region (such as the small aperture 34 of the pulmonary vein PV) is ablated. Of course, it will be understood that the techniques described herein may be used to ablate and / or map other regions of the heart 12.

[0064] In a first step, the physician 24 inserts the distal tip 28 and the guide wire 70 into the subject, and the guide sheath 90 surrounds the distal tip 28 in such a manner as to force the spine framework 200 into a collapsed configuration (from their shape-set expanded configuration). Next, the guide wire 70 is navigated within the heart 12. In this embodiment, within the heart 12, the guide wire 70 is navigated within the pulmonary vein PV.

[0065] After the guide wire 70 is sent into the pulmonary vein PV, the spine framework 100, the elongated shaft 80, and the guide sheath 90 are slid along the guide wire 70 until they are positioned near the small hole 34. When the distal tip 28 of the probe 14 is properly positioned, the guide sheath 90 can be actuated in the proximal direction (leftward with respect to the orientation shown in FIG. 7 and as indicated by the direction arrow). This actuation exposes the distal tip 28 and causes the spines 204 to bend outwardly into their shaped configuration (i.e., the expanded configuration). In the expanded configuration, the planar section 204B facing distally of the spine 204 including the electrodes 26 is pressed against the small hole 34. The flat contact surface 220 on which the electrodes 26 are disposed maximizes the contact area with the small hole 34.

[0066] 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 spine 204. If two or more electrodes 26 are present, then the supplied current may be bipolar, i.e., the current may flow between the electrodes 26 to transfer ablation energy to the tissue. Alternatively, the supplied ablation energy may be unipolar, i.e., a 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 body of the patient 23. For example, the return electrode may include a patch (e.g., patch 38, etc.) connected to the patient's body.

[0067] In some examples, an (alternating current) current, such as an RF sine wave, is supplied to electrode 26, so that RF ablation of tissue is performed. Alternatively, a pulsed current (e.g., DC or AC) may be supplied to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is supplied to perform PFA, the monopolar ablation energy can be supplied by the current flowing between electrode 26 on spine 204 and electrode patch 38 or the back patch. Further, the bipolar ablation energy can be supplied by the current flowing between electrode 26 itself and / or another catheter within another part of heart 12.

[0068] Depending on the arrangement and array of electrodes 26 on spine 204, a generally complete 360-degree band of ablation around small hole 34 can be achieved to provide pulmonary vein isolation. Electrode 26 can, for example, function therapeutically to ablate the small hole, and each electrode can ablate a predetermined area around small hole 34 to isolate the pulmonary vein without the need to reposition the distal tip 28 one or more times during treatment.

[0069] Optionally, electrode 26 can also be used to assist in identifying the position of distal tip 28 and / or to sense anatomical signals at small hole 34. For example, the location of electrode 26 can be confirmed by the current tracking module of PIU 30 using the impedance and / or current between electrode 26 and patch 38. Additionally, the location of the electrode can be confirmed by fluoroscopy. When electrode 26 is properly positioned in contact with small hole 34, electrode 26 generates a potential gradient signal, also referred to herein as an electrical signal, in response to the sensed potential. In some examples, the sensed electrical signal indicates at least one characteristic of an anatomical signal, such as the direction and propagation speed of the wavefront caused by an anatomical signal, such as an electrocardiogram (ECG) signal, within heart 12.

[0070] After ablation and / or mapping is complete, the physician 24 can slightly retract the distal tip 28 from the small hole and slide the guide sheath 90 back over the distal tip 28, whereby the spine 204 bends inwardly from the expanded configuration to the collapsed configuration. When the spine 204 collapses, the guide sheath 90, the medical probe 14, and the guide wire 70 can be retracted from the patient's body. Of course, while the guide sheath 90 has been described as the device that causes the expansion and collapse of the spine framework 200, it will be understood that other forms may be employed that operate the spine framework 200 between the expanded configuration and the collapsed configuration (and vice versa) without departing from the spirit and scope of the present disclosure.

[0071] FIG. 8A is a schematic drawing showing a perspective view of another exemplary distal tip 28 of a medical probe 14 in an expanded configuration and another spine framework 300. FIG. 8B is a schematic drawing showing a perspective view of the distal side of the distal tip 28 of the medical probe 14 in the expanded configuration having the spine framework 300 of FIG. 8A.

[0072] Referring now to FIG. 8A, another exemplary distal tip 28 of the catheter / medical probe 14 can be defined by a spine framework 300 that extends along the longitudinal axis 60 and has a proximal end, an intermediate section, and a distal end (similar to the aforementioned frameworks 100, 200). As seen in FIG. 8A, the framework 300 can be formed to take a shape similar to the shape of the frameworks 100, 200 in the expanded configuration. The framework 300 includes a neck 302 (extending from the proximal end) and a plurality of spines 304 connected to and extending from the neck 302 along the intermediate section to the distal end. Further, the framework 300 defines a lumen 330 (see FIG. 10) that is coaxial with the longitudinal axis 60.

[0073] In some examples, the framework 300 is formed from a series of flexible resilient rods or tubes (e.g., formed from a shape memory alloy such as nitinol) each including a first end 302A and a second end 302B that define portions of the neck 302 (when all of the first end 302A and the second end 302B are assembled / connected together, they jointly form the neck 302 that defines the lumen 330). Each rod is bent to include a loop portion 304 that forms the spine 304 of the framework 300 and is shaped to be biased to curve outwardly into an expanded configuration, as shown in FIG. 8A. In the expanded configuration, each bent rod resembles a flower petal. Due to the flexible and elastic nature of the material, the spine 304 can also move to a collapsed configuration (such as that shown in FIG. 9) where the spine 304 extends along the longitudinal axis 60.

[0074] In the expanded configuration, each loop portion 304 has two curved sections 304A that curve away from the longitudinal axis 60 and a planar section 304B that extends linearly from the curved section 304A along the plane 320 and forms a loop around the distal end of each spine 304. In other words, the planar section 304B loops from the first end 302A towards the second end 302B and connects the curved sections 304A to form a partial loop shape. As seen in FIG. 8A, the plane 320 is substantially orthogonal to the longitudinal axis 60.

[0075] Referring now to FIG. 8B, to form the distal tip 28 of the probe 14, the spine framework 300 is connected to a flexible elongated shaft 80. Further, a plurality of electrodes 26 are formed on or around the planar section 304B of each spine 304 (discussed in more detail below) to maximize contact with the diseased area of the heart 12. More specifically, the electrodes 26 are formed on the spine 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 fabricated, for example, using conductive epoxy, using a flexible printed circuit board (PCB), by a deposition layer, or using ring electrodes.

[0076] The flexible membrane 310 can also be attached to surround each spine 304 and the neck 302. In some embodiments, the flexible membrane 310 is made of a biocompatible insulating material.

[0077] FIG. 9 is a schematic drawing showing a cross-sectional view of the distal tip 28 of FIG. 8B in a collapsed configuration and proximal to the ostium 34 of the pulmonary vein PV. FIG. 10 is a schematic drawing showing a cross-sectional view of the distal tip 28 of FIG. 8B in an expanded configuration and pressed against the ostium 34 of the pulmonary vein PV.

[0078] Specifically referring to FIGS. 9-10, in addition to the medical probe 14, the system according to the technology disclosed herein further includes a guide wire 70 and a guide sheath 90. The guide wire 70 passes through the framework lumen 330 of the distal tip 28, through the lumen 82 of the elongated shaft 80, and is sent to the proximal end of the medical probe (including, for example, the handle). The guide sheath 90 is slidable relative to the distal tip 28 of the medical probe 14 and will be described in more detail below.

[0079] In the following description, by way of example, it is assumed that the target area (such as the ostium 34 of the pulmonary vein PV) is ablated. Of course, it will be understood that the techniques described herein may be used to ablate and / or map other areas of the heart 12.

[0080] In a first step, the physician 24 inserts the distal tip 28 and the guide wire 70 into the target, and the guide sheath 90 surrounds the distal tip 28 in such a manner as to force the spine framework 300 into a collapsed configuration (from their shape-setting expanded configuration). Next, the guide wire 70 is navigated into the heart 12. In this embodiment, within the heart 12, the guide wire 70 is navigated into the pulmonary vein PV.

[0081] After the guide wire 70 is sent into the pulmonary vein PV, the spine framework 300, the elongate shaft 80, and the guide sheath 90 are slid along the guide wire 70 until they are positioned near the small hole 34. When the distal tip 28 of the probe 14 is properly positioned, the guide sheath 90 can be actuated in the proximal direction (leftward with respect to the orientation shown in FIG. 10 and as indicated by the direction arrow). This actuation exposes the distal tip 28 and causes the spines 304 to bend outwardly into their shape-setting form (i.e., the expanded configuration). In the expanded configuration, as shown in FIG. 10, the planar section 304B facing distally of the spine 304 including the electrode 26 is pressed against the small hole 34. The flat contact surface 320 on which the electrode 26 is disposed maximizes the contact area with the small hole 34.

[0082] 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 spine 304. If two or more electrodes 26 are present, then the supplied current may be bipolar, i.e., the current may flow between the electrodes 26 to transmit ablation energy to the tissue. Alternatively, the supplied ablation energy may be unipolar, i.e., a 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 body of the patient 23. For example, the return electrode may include a patch (such as the patch 38 etc.) connected to the patient's body.

[0083] In some examples, an (alternating current) current, such as an RF sine wave, is supplied to electrode 26 so that RF ablation of tissue is performed. Alternatively, a pulsed current (e.g., DC or AC) may be supplied to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is supplied to perform PFA, the monopolar ablation energy can be supplied by the current flowing between electrode 26 on spine 204 and electrode patch 38 or the back patch. Further, bipolar ablation energy can be supplied by the current flowing between electrode 26 itself and / or another catheter within another part of heart 12.

[0084] Depending on the placement and arrangement of electrode 26 on spine 304, a generally complete 360-degree band of ablation around small hole 34 can be achieved to provide pulmonary vein isolation. Electrode 26 can, for example, function therapeutically to ablate the small hole, and each electrode ablates a predetermined area around small hole 34 to isolate the pulmonary vein without the need to reposition the distal tip 28 one or more times during treatment.

[0085] Optionally, electrode 26 can also be used to assist in identifying the location of distal tip 28 and / or to sense anatomical signals at small hole 34. For example, the location of electrode 26 can be confirmed by the current tracking module of PIU 30 using the impedance and / or current between electrode 26 and patch 38. Additionally, the location of the electrode can be confirmed by fluoroscopy. When electrode 26 is properly positioned in contact with small hole 34, electrode 26 generates a potential gradient signal, also referred to herein as an electrical signal, in response to the sensed potential. In some examples, the sensed electrical signal indicates at least one characteristic of an anatomical signal, such as the direction and propagation speed of a wavefront caused by an anatomical signal, such as an electrocardiogram (ECG) signal within heart 12.

[0086] After ablation and / or mapping is complete, physician 24 can slightly retract the distal tip 28 from the small aperture 34 and slide the guide sheath 90 back over the distal tip 28, whereby the spine 304 bends inwardly from the expanded configuration to the collapsed configuration. When the spine 304 collapses, the guide sheath 90, the medical probe 14, and the guide wire 70 can be retracted from the patient's body. Of course, while the guide sheath 90 has been described as a device that causes expansion and collapse of the spine framework 300, it will be understood that other forms may be employed that operate the spine framework 300 between (and vice versa) an expanded configuration and a collapsed configuration without departing from the spirit and scope of the present disclosure.

[0087] Figure 11A is a schematic drawing showing a perspective view of a spine framework 400 of yet another distal tip 28 of the medical probe 14 in an expanded configuration. Figure 2B is a schematic drawing showing a perspective view of the spine framework 400 of Figure 11A in a collapsed configuration. Figure 2C is a schematic drawing showing a perspective view of the distal side of the distal tip 28 having the spine framework 400 in an expanded configuration. Figure 2D is a schematic drawing showing a perspective view of the proximal side of the distal tip 28 of Figure 2C in an expanded configuration.

[0088] Referring now to FIG. 11A, another exemplary distal tip 28 of the catheter / medical probe 14 can be defined by a spine framework 400 that extends along the longitudinal axis 60 and has a proximal end 400A, an intermediate section 400B, and a distal end 400C (similar to the aforementioned frameworks 100, 200, 300). As seen in FIG. 11A, the framework 400 can be formed to take a shape similar to that of a basket catheter. The framework 400 includes a neck 402 (extending from the proximal end 400A) and a plurality of spines 404 (extending along the intermediate section 400B) connected to and extending from the neck 402. The spines 404 connect to a crown 406 that defines the distal end 400C on the side opposite the side connecting to the neck 402. Further, the framework 400 defines a lumen 430 (see FIG. 13) that is coaxial with the longitudinal axis 60.

[0089] In some examples, the framework 400 is single (i.e., monolithic) and formed from a flexible elastic material (e.g., nitinol). The framework 400 can be formed from a flat or cylindrical tube stock of the material using any suitable method. For example, the framework 400 can be formed by cutting, laser cutting, stamping, combinations thereof, etc., such that it is divided to form the spines 404 and define the neck 402 and the crown 406. Alternatively or additionally, the framework 400 can be formed such that a portion 404B2 of the spine 404 extends from a junction section between two pieces 404A, 404B of the spine 404. Due to the elastic nature of the material, the framework 400 can be shaped to be biased into either an expanded configuration as shown in FIG. 11A or a collapsed configuration as shown in FIG. 11B.

[0090] In addition to the above, each spine 404 includes a straight section 404A connected to the neck 402 and a second straight section 404B connected to the first straight section 404A, and as a junction, it is in the middle of both ends of the second straight section. In the collapsed configuration, each connected first straight section 404A and second straight section 404B are oriented at a first angle with respect to each other. In the expanded configuration, each connected first straight section 404A and second straight section 404B are oriented at a second angle with respect to each other, and the second angle is smaller than the first angle (as can be seen by comparing FIG. 11A with FIG. 11B, for example). In the collapsed configuration, each spine 404 extends along the longitudinal axis 60 (but does not necessarily have to be completely parallel thereto). The width of each spine 404 can be adjusted to change the rigidity of the framework 400.

[0091] Referring now to FIG. 11B, to form the distal tip 28 of the probe 14, the spine framework 300 is connected to a flexible elongate shaft 80 that includes a shuttle lumen 82. The flexible membrane 410 is also connected to the spine framework 400 on a portion 404B1 of the second straight section 404B of the spine 104 that faces distally (with respect to the proximal end of the probe 14) in the expanded configuration and faces outwardly in the collapsed configuration. When connected to the spine 404, the membrane 410 and the spine 404 generally resemble the shape of an umbrella and are generally conical. In some examples, the flexible membrane 410 is made of a biocompatible elastomeric material.

[0092] Further, a plurality of electrodes 26 are formed on a section of the membrane 420 that faces distally, and in conjunction with the conical shape of the membrane in the expanded configuration, maximize contact with the diseased area of the heart 12 (to be considered in more detail below). The electrodes 26 shown in this example can be made, for example, using conductive epoxy, using a flexible printed circuit board (PCB), or by a vapor deposition layer.

[0093] FIG. 12 is a schematic drawing showing a cross-section of the distal tip 28 of FIG. 11C in a collapsed configuration and proximal to the small aperture 34 of the pulmonary vein PV. FIG. 13 is a schematic drawing showing a cross-sectional view of the distal tip 28 of FIG. 11C in an expanded configuration and pressed against the small aperture 34 of the pulmonary vein PV.

[0094] Referring specifically to FIGS. 12-13, in addition to the medical probe 14, the system according to the technology disclosed herein further includes a guidewire 70 and an actuator 92 (embodied as a push / pull rod in this embodiment, but may take other forms such as a pull wire). The guidewire 70 passes through the framework lumen 430 of the distal tip 28, through the lumen 82 of the elongate shaft 80, and is sent to the proximal end of the medical probe (including, for example, a handle). The push rod is connected to either the crown 406 or the neck 402 of the spine framework 400 and will be described in more detail below.

[0095] In the following description, by way of example, it is assumed that a target region (such as the small aperture 34 of the pulmonary vein PV) is ablated. Of course, it will be understood that the technology described herein may be used to ablate and / or map other regions of the heart 12.

[0096] In a first step, the physician 24 inserts the distal tip 28 and the guidewire 70 into the target, and the push rod 92 is positioned to bias the spine framework 400 into a collapsed configuration. For example, when connected to the crown 406, a distal force on the push rod 92 (i.e., rightward with respect to FIG. 12) maintains the framework 400 in a collapsed configuration, while when connected to the neck 402, the neck 402 can be made slidable such that a proximal force on the push rod 92 (i.e., leftward with respect to FIG. 13 as indicated by the direction arrow) maintains the framework 400 in a collapsed configuration. Next, the guidewire 70 is navigated within the heart 12. In this embodiment, within the heart 12, the guidewire 70 is navigated within the pulmonary vein PV.

[0097] After the guide wire 70 is sent into the pulmonary vein PV, the spine framework 400, the elongated shaft 80, and the push rod 92 are slid along the guide wire 70 until they are positioned near the small hole 34. When the distal tip 28 of the probe 14 is properly positioned, the push rod 92 (when connected to the crown 406) can be actuated in the proximal direction (leftward with respect to the orientation shown in FIG. 13 and as indicated by the direction arrow as described above). This actuation exposes the distal tip 28, and as a result, the spine 304 bends outward into an expanded configuration. In the expanded configuration, the conical shape of the membrane 410 including the electrodes 26 is optimized to maximize the contact area when pressed against the small hole 34, as shown in FIG. 13.

[0098] 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 membrane 410. If two or more electrodes 26 are present, then the supplied current may be bipolar, i.e., the current may flow between the electrodes 26 to transfer ablation energy to the tissue. Alternatively, the supplied ablation energy may be unipolar, i.e., a 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 body of the patient 23. For example, the return electrode may include a patch (such as patch 38, etc.) connected to the patient's body.

[0099] In some examples, (alternating current) current such as an RF sine wave is supplied to electrode 26, and thus RF ablation of tissue is performed. Alternatively, pulsed current (e.g., DC or AC) may be supplied to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When pulsed current is supplied to perform PFA, monopolar ablation energy can be supplied by current flowing between electrode 26 on spine 204 and electrode patch 38 or the back patch. Further, bipolar ablation energy can be supplied by current flowing between electrode 26 itself and / or another catheter within another part of heart 12.

[0100] Depending on the arrangement and array of electrodes 26 on membrane 410, it is possible to achieve ablation of a generally complete 360-degree band around small hole 34 to provide pulmonary vein isolation. Electrode 26 can, for example, function therapeutically to ablate the small hole, and each electrode ablates a predetermined area around small hole 34 to isolate the pulmonary vein without the need to reposition the distal tip 28 one or more times during treatment.

[0101] Optionally, electrode 26 can also be used to assist in identifying the location of distal tip 28 and / or to sense anatomical signals at small hole 34. For example, the location of electrode 26 can be confirmed by the current tracking module of PIU 30 using the impedance and / or current between electrode 26 and patch 38. Additionally, the location of the electrode can be confirmed by fluoroscopy. When electrode 26 is properly positioned in contact with small hole 34, electrode 26 generates a potential gradient signal, also referred to herein as an electrical signal, in response to the sensed potential. In some examples, the sensed electrical signal indicates at least one characteristic of an anatomical signal, such as the direction and propagation speed of a wavefront caused by an anatomical signal such as an electrocardiogram (ECG) signal within heart 12.

[0102] After ablation and / or mapping is complete, physician 24 can slightly retract the distal tip 28 from the small hole 34 and slide the push rod 92 distally to bend the spine 404 from the expanded configuration to the collapsed configuration. When the spine 404 collapses, the guide sheath 90, the medical probe 14, and the guide wire 70 can be retracted from the patient's body. Of course, while the push rod 92 has been described as a device that causes expansion and collapse of the spine framework 400, it will be understood that other forms of actuation between the expanded configuration and the collapsed configuration (and vice versa) of the spine framework 400 may be employed without departing from the spirit and scope of the present disclosure.

[0103] The technology of the present disclosure described herein can be further understood in accordance with the following clauses. Clause 1. A distal tip of a medical probe, the distal tip comprising a spine framework having a proximal end, an intermediate section, and a distal end and extending along a longitudinal axis, the spine framework comprising a neck extending from the proximal end and a plurality of spines connected to the neck and extending from the neck along the intermediate section to the distal end, each spine comprising a collapsed configuration extending generally parallel to the longitudinal axis, a curved section where each spine bends away from the longitudinal axis, and a planar section extending from the curved section to the distal end, each planar section extending along a plane generally orthogonal to the longitudinal axis, and being movable between an expanded configuration.

[0104] Clause 2. The distal tip according to clause 1, wherein each spine extends generally parallel to the longitudinal axis in the collapsed configuration.

[0105] Clause 3. The distal tip according to clause 1 or 2, wherein the spine framework defines a lumen therethrough.

[0106] Clause 4. The distal tip according to any one of clauses 1 to 3, wherein the spine framework comprises a shape memory alloy material.

[0107] Clause 5. The distal tip according to any one of Clauses 1 to 4, further comprising a plurality of electrodes connected to the spine framework.

[0108] Clause 6. The distal tip according to Clause 5, wherein each electrode comprises at least one of a conductive epoxy, a flexible printed circuit board, a vapor deposition layer, or a ring electrode.

[0109] Clause 7. The distal tip according to any one of Clauses 1 to 4, wherein each planar section terminates at the distal end.

[0110] Clause 8. The distal tip according to Clause 7, further comprising a flexible membrane connected to a planar section of the spine, the flexible membrane comprising a first portion extending along a plane in an expanded configuration.

[0111] Clause 9. The distal tip according to Clause 8, wherein the flexible membrane is further connected to an arcuate section of the spine.

[0112] Clause 10. The distal tip according to Clause 8 or 9, further comprising one or more electrodes connected to the first portion of the flexible membrane.

[0113] Clause 11. The distal tip according to Clause 7, further comprising a plurality of flexible membranes, each flexible membrane surrounding a respective spine.

[0114] Clause 12. The distal tip according to Clause 11, further comprising one or more ring electrodes connected to each spine.

[0115] Clause 13. The distal tip according to any one of Clauses 1 to 4, wherein the spine framework comprises a plurality of rods, each rod comprising a first end, a second end, and a loop portion connecting the first end and the second end, the first end and the second end of the rod being joined to form a neck, and the loop portion forming the spine.

[0116] Clause 14. The distal tip according to Clause 13, further comprising a plurality of flexible membranes, each flexible membrane surrounding a respective spine.

[0117] Clause 15. The distal tip according to Clause 14, further comprising one or more ring electrodes connected to each spine.

[0118] Clause 16. A distal tip of a medical probe, the distal tip having a proximal end, an intermediate section, and a distal end, and comprising a spine framework extending along a longitudinal axis, the spine framework comprising a neck extending from the proximal end, a plurality of spines extending along the intermediate section, each spine comprising a first straight section connected to the neck and a second straight section having a first end and a second end, the first straight section being connected to the second straight section at a junction intermediate the first end and the second end, a plurality of spines, a crown connected to the second straight section and extending to the distal end, the spine framework being movable between a collapsed configuration in which each connected first straight section and second straight section are oriented at a first angle with respect to each other and an expanded configuration in which each connected first straight section and second straight section are oriented at a second angle with respect to each other, the second angle being smaller than the first angle.

[0119] Clause 17. The distal tip according to Clause 16, further comprising a flexible membrane connected to the second straight section.

[0120] Clause 18. The distal tip according to Clause 17, further comprising one or more electrodes connected to the flexible membrane.

[0121] Clause 19. The distal tip according to Clause 18, wherein each electrode comprises at least one of a conductive epoxy, a flexible printed circuit board, or a vapor deposition layer.

[0122] Clause 20. The distal tip according to any one of Clauses 17 to 19, wherein the flexible membrane has a conical shape in the extended configuration of the spine framework.

[0123] Clause 21. The distal tip according to any one of Clauses 16 to 20, wherein each spine extends along the longitudinal axis in a collapsed configuration.

[0124] Clause 22. The distal tip according to any one of Clauses 16 to 21, wherein the spine framework defines a lumen therethrough.

[0125] Clause 23. The distal tip according to any one of Clauses 16 to 22, wherein the spine framework includes a shape memory alloy material.

[0126] Clause 24. A system comprising a medical probe having an elongated shaft extending along a longitudinal axis, and a distal tip of the medical probe, the distal tip having a proximal end, an intermediate section, and a distal end, and comprising a spine framework extending along the longitudinal axis, the spine framework comprising a neck extending from the proximal end, and a plurality of spines connected to the neck and extending from the intermediate section to the distal end, the spines having a collapsed configuration in which the spines extend along the longitudinal axis, each spine having a curved section that bends away from the longitudinal axis, and a planar section extending from the curved section to the distal end, each planar section being movable between an extended configuration extending along a plane substantially orthogonal to the longitudinal axis, and a distal tip. A medical probe, a guide wire extending through the elongated shaft and the distal tip, and a guide sheath slidable relative to the distal tip to move the spine between the collapsed configuration and the extended configuration.

[0127] Clause 25. The system according to Clause 24, wherein the elongated shaft defines a lumen, the spine framework defines a lumen, and the guide wire extends through the lumen.

[0128] Clause 26. The system according to clause 24 or 25, further comprising a plurality of electrodes connected to the spine framework.

[0129] Clause 27. The system according to any one of clauses 24 to 27, wherein the spine is biased in an extended configuration.

[0130] Clause 28. A system, comprising a medical probe, the medical probe comprising an elongated shaft extending along a longitudinal axis, a spine framework having a proximal end, an intermediate section, and a distal end, and extending along the longitudinal axis, the spine framework comprising a neck extending from the proximal end, and a plurality of spines extending along the intermediate section, each spine comprising a first straight section connected to the neck, and a second straight section having a first end and a second end, the first straight section being connected to the second straight section at a junction intermediate the first end and the second end, the second straight section, and a crown connected to the second straight section and extending to the distal end, the spine framework being movable between a collapsed configuration in which each connected first straight section and second straight section are oriented at a first angle with respect to each other, and an extended configuration in which each connected first straight section and second straight section are oriented at a second angle with respect to each other, the second angle being smaller than the first angle, and a distal tip portion, a guide wire extending through the elongated shaft and the distal tip portion, and a rod or wire connected to one of the neck or the crown and operable to move the spine framework between the collapsed configuration and the extended configuration.

[0131] Clause 29. The system according to clause 28, wherein the elongated shaft defines a lumen, the spine framework defines a lumen, and the guide wire extends through the lumen.

[0132] Clause 30. The system according to clause 28 or 29, further comprising a plurality of electrodes connected to the spine framework.

[0133] Clause 31. The system according to any one of Clauses 28 to 30, wherein the spine is biased to an extended configuration or a collapsed configuration.

[0134] Clause 32. A method of fabricating a distal tip of a medical probe, the method comprising cutting a tube extending along a longitudinal axis to define a neck and a plurality of spines, each spine comprising a curved section that curves away from the longitudinal axis and a planar section extending from the curved section, the method further comprising shaping the spines such that each planar section extends along a plane substantially orthogonal to the longitudinal axis.

[0135] Clause 33. A method of fabricating a distal tip of a medical probe, the method comprising shaping a plurality of rods such that each rod comprises a first end extending along a longitudinal axis, a first curved section extending from the first end and curving away from the longitudinal axis, a planar section extending from the curved section and forming a partial loop shape, the planar section extending along a plane substantially orthogonal to the longitudinal axis, a second curved section extending from the planar section and curving towards the longitudinal axis, and a second end extending from the second curved section and extending along the longitudinal axis, and connecting the rods together such that the first end and the second end define a lumen.

[0136] Article 34. A method of using a medical probe, wherein the medical probe comprises a distal tip having a proximal end, an intermediate section, and a distal end, and comprising a spine framework extending along a longitudinal axis, the spine framework comprising a neck extending from the proximal end and a plurality of spines connected to the neck and extending along the intermediate section to the distal end, a plurality of electrodes being connected to the spine framework, the method comprising moving the spines from a collapsed configuration in which the spines extend along the longitudinal axis to an expanded configuration in which each spine comprises a curved section that curves away from the longitudinal axis and a planar section extending from the curved section to the distal end, each planar section extending along a plane substantially orthogonal to the longitudinal axis, and positioning the planar section in contact with the pulmonary vein ostium such that the electrodes are disposed in contact with the pulmonary vein ostium.

[0137] Article 35. A method of using a medical probe, wherein the medical probe comprises a distal tip having a proximal end, an intermediate section, and a distal end, and comprising a spine framework extending along a longitudinal axis, the spine framework comprising a neck extending from the proximal end, a plurality of spines extending along the intermediate section, and a crown connected to a second straight section and extending to the distal end, each spine comprising a first straight section connected to the neck and a second straight section having a first end and a second end, the first straight section being connected to the second straight section at a junction intermediate the first end and the second end, the method comprising moving the spine framework from a collapsed configuration in which each connected first straight section and second straight section are oriented at a first angle with respect to each other to an expanded configuration in which each connected first straight section and second straight section are oriented at a second angle with respect to each other, the second angle being smaller than the first angle, and positioning the second straight section in contact with the pulmonary vein ostium such that the electrodes are disposed in contact with the pulmonary vein ostium.

[0138] The above embodiments are cited as examples, and the disclosed technology is not limited to what is specifically illustrated and described in the above specification. Rather, the scope of the disclosed technology includes both the various combinations and sub - combinations of the features described above, as well as those variations and modifications thereof that are not disclosed in the prior art and that would occur to those skilled in the art upon reading the foregoing description.

[0139] 〔Embodiment〕 (1) A distal tip of a medical probe, wherein the distal tip has a proximal end, an intermediate section, and a distal end, and comprises a spine framework extending along a longitudinal axis, the spine framework having a neck extending from the proximal end, and a plurality of spines connected to the neck and extending from the neck along the intermediate section to the distal end, the spines having a collapsed configuration in which the spines extend substantially parallel to the longitudinal axis, and each spine having a curved section that bends away from the longitudinal axis and a planar section extending from the curved section to the distal end, each planar section being movable between an expanded configuration in which it extends along a plane substantially orthogonal to the longitudinal axis. (2) The distal tip according to embodiment 1, wherein each spine extends substantially parallel to the longitudinal axis in the collapsed configuration. (3) The distal tip according to embodiment 1, wherein the spine framework defines a lumen therethrough. (4) The distal tip according to embodiment 1, further comprising a plurality of electrodes connected to the spine framework. (5) The distal tip according to embodiment 1, wherein each planar section terminates at the distal end.

[0140] (6) The distal tip according to embodiment 5, further comprising a flexible membrane connected to the planar section of the spine, the flexible membrane having a first portion that extends along the plane in the expanded configuration. (7) The distal tip according to embodiment 6, wherein the flexible membrane is further connected to the arcuate section of the spine. (8) The distal tip according to embodiment 6, further comprising one or more electrodes connected to the first portion of the flexible membrane. (9) The distal tip according to embodiment 5, further comprising a plurality of flexible membranes, each flexible membrane surrounding a respective spine. (10) The distal tip according to embodiment 9, further comprising one or more ring electrodes connected to each spine.

[0141] (11) The spine framework comprises a plurality of rods, each rod having a first end, a second end, and a loop portion connecting the first end and the second end, and the first end and the second end of the rod are joined to form the neck, the loop portion forms the spine, the distal tip according to embodiment 1. (12) The distal tip according to embodiment 11, further comprising a plurality of flexible membranes, each flexible membrane surrounding a respective spine. (13) The distal tip according to embodiment 12, further comprising one or more ring electrodes connected to each spine. (14) A distal tip of a medical probe, the distal tip having a proximal end, an intermediate section, and a distal end, and comprising a spine framework extending along a longitudinal axis, the spine framework having a neck extending from the proximal end, a plurality of spines extending along the intermediate section, each spine having a first straight section connected to the neck, and a second straight section having a first end and a second end, the first straight section being connected to the second straight section at a junction intermediate the first end and the second end, a plurality of spines. A crown connected to the second straight section and extending to the distal end. The spine framework is A collapsed configuration in which each connected first straight section and second straight section are oriented at a first angle with respect to each other, A distal tip that is movable between an expanded configuration in which each connected first straight section and second straight section are oriented at a second angle with respect to each other, the second angle being smaller than the first angle. (15) The distal tip according to embodiment 14, further comprising a flexible membrane connected to the second straight section.

[0142] (16) The distal tip according to embodiment 15, further comprising one or more electrodes connected to the flexible membrane. (17) The distal tip according to embodiment 15, wherein the flexible membrane has a conical shape in the expanded configuration of the spine framework. (18) The distal tip according to embodiment 14, wherein each spine extends along the longitudinal axis in the collapsed configuration. (19) The distal tip according to embodiment 14, wherein the spine framework defines a lumen therethrough. (20) A system, A medical probe, An elongated shaft extending along a longitudinal axis, A distal tip of the medical probe, the distal tip having a proximal end, an intermediate section, and a distal end, and comprising a spine framework extending along a longitudinal axis, the spine framework having A neck extending from the proximal end, A plurality of spines connected to the neck and extending along the intermediate section to the distal end, the spines having A collapsed configuration in which the spines extend along the longitudinal axis, The distal tip portion is movable between an expanded configuration in which each spine includes a curved section that curves away from the longitudinal axis and a planar section that extends from the curved section to the distal end, and each planar section extends along a plane that is substantially orthogonal to the longitudinal axis, and a medical probe comprising the same. A guide wire extending through the elongated shaft and the distal tip portion. A system comprising a guide sheath slidable relative to the distal tip portion to move the spine between the collapsed configuration and the expanded configuration.

Claims

1. 1. A distal tip of a medical probe, the distal tip comprising a spine framework having a proximal end, a midsection, and a distal end and extending along a longitudinal axis, the spine framework comprising: a neck extending from the proximal end; a plurality of spines connected to the neck and extending along the midsection to the distal end, the spines comprising: a collapsed configuration in which the spine extends along the longitudinal axis; an expanded configuration, in which each spine includes a curved section that bends away from the longitudinal axis and a planar section that extends from the curved section to the distal end, each planar section extending along a plane generally perpendicular to the longitudinal axis; and an expanded configuration, in which each spine includes a curved section that bends away from the longitudinal axis and a planar section that extends from the curved section to the distal end, each planar section extending along a plane generally perpendicular to the longitudinal axis.

2. The distal tip of claim 1 , wherein each spine extends generally parallel to the longitudinal axis in the collapsed configuration.

3. The distal tip of claim 1 , wherein the spine framework defines a lumen therethrough.

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

5. The distal tip of claim 1 , wherein each planar section terminates at the distal end.

6. The distal tip of claim 5 , further comprising a flexible membrane connected to the planar section of the spine, the flexible membrane comprising a first portion that extends along the plane in the expanded configuration.

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

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

11. The spine framework comprises a plurality of rods, each rod comprising: A first end, A second end, and a loop portion connecting the first end and the second end, the first end and the second end of the rod join to form the neck; The distal tip of claim 1 , wherein the loop portion forms the spine.

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

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

14. 1. A distal tip of a medical probe, the distal tip comprising a spine framework having a proximal end, a midsection, and a distal end and extending along a longitudinal axis, the spine framework comprising: a neck extending from the proximal end; A plurality of spines extending along the midsection, each spine comprising: a first straight section connected to the neck; a second straight section having a first end and a second end, the first straight section being connected to the second straight section at a junction intermediate the first end and the second end; a crown connected to the second straight section and extending to the distal end; The spine framework comprises: a collapsed configuration, wherein each connected first and second linear section is oriented at a first angle relative to one another; an expanded configuration, in which each connected first and second straight sections are oriented at a second angle relative to one another, the second angle being less than the first angle, the distal tip being movable between an expanded configuration, in which each connected first and second straight sections are oriented at a second angle relative to one another, 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 section.

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 , wherein the flexible membrane comprises a conical shape in the expanded configuration of the spine framework.

18. The distal tip of claim 14 , wherein each spine extends along the longitudinal axis in the collapsed configuration.

19. The distal tip of claim 14 , wherein the spine framework defines a lumen therethrough.

20. 1. A system comprising:

1. A medical probe comprising: an elongate shaft extending along a longitudinal axis; 1. A distal tip of a medical probe, the distal tip comprising a spine framework having a proximal end, a midsection, and a distal end and extending along a longitudinal axis, the spine framework comprising: a neck extending from the proximal end; a plurality of spines connected to the neck and extending along the mid-section to the distal end, the spines comprising: a collapsed configuration in which the spine extends along the longitudinal axis; an extended configuration, wherein each spine includes a curved section that bends away from the longitudinal axis and a planar section that extends from the curved section to the distal end, each planar section extending along a plane generally perpendicular to the longitudinal axis; a guidewire extending through the elongate shaft and the distal tip; a guide sheath that is slidable relative to the distal tip to move the spine between the collapsed configuration and the expanded configuration.

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