Medical probe for navigating small-diameter blood vessels

Abstract

The disclosed techniques include a medical probe including an elongate shaft, a guidewire, a coil, and an electrode. The elongate shaft extends along a longitudinal axis and is dimensioned to be inserted into a Marshall vein. The guidewire extends through a lumen in the elongate shaft. The coils are connected to the distal end of the elongate shaft, and each coil is configured to generate a current indicative of a position of the respective coil when subjected to a magnetic field. The electrode is connected to the distal tip. Each electrode is designed to either (i) sense an anatomical signal in the Marshall vein and provide an electrical signal indicative of the anatomical signal, or (ii) deliver ablation energy to a target tissue region proximate the Marshall vein.

Description

Technical Field

[0001] The present technology generally relates to medical devices, and more particularly to medical probes having electrodes, and further but not exclusively to medical probes suitable for position tracking, anatomical sensing, and / or inducing irreversible electroporation (IRE) of cardiac tissue. Background Art

[0002] The ligament of Marshall (LOM) on the epicardium between the left atrial appendage and the left pulmonary vein is typically the source of paroxysmal atrial fibrillation (AF). Arrhythmias, such as AF, occur when electrical signals abnormally propagate from a region of cardiac tissue to adjacent tissue. This disrupts the normal cardiac cycle and results in an irregular heartbeat. Certain procedures are used to treat arrhythmias, including surgically disrupting the source of the arrhythmia signal and disrupting the conduction pathways for such signals. Selective ablation of cardiac tissue by applying energy via a catheter can sometimes stop or alter the propagation of unwanted electrical signals from one part of the heart to another.

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

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

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

[0006] Many regions of the heart are relatively easily accessible endocardially and are thus suitable for ablation by conventional catheters such as focal catheters or balloon catheters. However, certain regions of the heart (such as the LOM) are generally difficult to access endocardially, typically because the possible endocardial pathways are tortuous, including one or more relatively acute bends that conventional catheters cannot traverse. Although these regions may be accessible epicardially in some cases, endocardial access is preferred. SUMMARY OF THE INVENTION

[0007] According to the disclosed technology, a medical probe is provided that includes an elongate shaft, a guidewire, a plurality of coils, and a plurality of electrodes. The elongate shaft extends along a longitudinal axis and is sized to be inserted into the Marshall vein. The elongate shaft includes a distal end and defines a lumen. The guidewire extends through the lumen. The coils are connected to the distal end along the longitudinal axis, where each coil is configured to generate a current when subjected to a magnetic field. The current indicates the position of the corresponding coil. The electrodes are connected to the distal end along the longitudinal axis, and each electrode is configured to: (i) sense an anatomical signal in the Marshall vein and provide an electrical signal indicative of the anatomical signal, or (ii) deliver ablation energy to a target tissue region adjacent to the Marshall vein.

[0008] According to the disclosed technology, a method for navigating a medical probe to the Marshall vein is also provided. The method includes the steps of inserting a guidewire through the coronary sinus into the Marshall vein. The method includes the steps of sliding an elongate shaft that extends along the longitudinal axis over the guidewire, through the coronary sinus, and into the Marshall vein, where the elongate shaft includes a distal end and where a plurality of coils and a plurality of electrodes are connected to the distal end. The method includes the steps of generating a corresponding current in each of the plurality of coils by subjecting each coil to a magnetic field, the current indicating the position of the corresponding coil. The method includes the steps of positioning the distal end within the Marshall vein. The method includes the steps of sensing an anatomical signal in the Marshall vein using at least one of the plurality of electrodes. The method includes the steps of providing an electrical signal indicative of the anatomical signal from the at least one electrode.

[0009] According to the disclosed technology, a system is also provided that includes a medical probe and a processor. The medical probe includes a slender shaft, a guide wire, a plurality of coils, and a plurality of electrodes. The slender shaft extends along a longitudinal axis and is sized to be inserted into the Marshall vein. The slender shaft includes a distal end and defines a lumen therethrough. The guide wire extends through the lumen. The plurality of coils are connected to the distal end along the longitudinal axis, and each coil is configured to generate a current when subjected to a magnetic field, the current indicating the position of the corresponding coil. The electrodes are connected to the distal end along the longitudinal axis, wherein each electrode is configured to: (i) sense an anatomical signal in the Marshall vein and provide an electrical signal indicative of the anatomical signal, or (ii) deliver ablation energy to a target tissue region adjacent to the Marshall vein. The processor is configured to estimate the position of the distal end based on the generated current and, (i) estimate at least one characteristic of the anatomical signal based on the electrical signal, or (ii) provide a signal to deliver the ablation energy to the electrode.

[0010] According to the disclosed technology, a system is also provided that includes a slender probe and a guide wire catheter. The slender probe extends along a longitudinal axis and is sized to be inserted into the coronary sinus. The slender catheter shaft includes an opening. The guide wire catheter extends through the opening along the longitudinal axis and is sized to be inserted into the Marshall vein. A first plurality of electrodes are connected to the slender probe along the longitudinal axis. A second plurality of electrodes are connected to the guide wire catheter along the longitudinal axis. Each electrode of the first plurality of electrodes and the second plurality of electrodes is configured to: (i) generate a current indicative of the position of the corresponding electrode, and (ii) sense an anatomical signal of tissue and provide an electrical signal indicative of the anatomical signal.

[0011] According to the disclosed technology, a method for navigating a medical probe to the Marshall vein is also provided. The method includes the steps of: inserting a slender probe extending along a longitudinal axis into the coronary sinus, wherein the slender probe defines an opening and includes a first plurality of electrodes. The method includes the steps of: sliding a guide wire catheter through the slender probe and out of the opening of the slender probe into the Marshall vein, wherein the guide wire catheter includes a second plurality of electrodes. The method includes the steps of: generating a corresponding current in each electrode of the first plurality of electrodes and the second plurality of electrodes, the corresponding current indicating the position of each corresponding electrode. The method includes the steps of: sensing an anatomical signal in the Marshall vein using at least one of the second plurality of electrodes. The method includes the steps of: providing an electrical signal indicative of the anatomical signal from at least one of the second plurality of electrodes. Description of the Drawings

[0012] Figure 1is a schematic diagram of a medical system according to the disclosed technology, the medical system including a medical probe having a distal end, the distal end including an electrode;

[0013] Figure 2 is a schematic diagram showing a perspective view of a medical probe having an electrode according to the disclosed technology, with a portion of the elongated probe body cut away;

[0014] Figure 3 is a schematic diagram showing a cross-sectional side view of a probe body according to the disclosed technology;

[0015] Figure 4 is a schematic diagram showing a probe body inserted into the Marshall vein according to the disclosed technology;

[0016] Figure 5 is a schematic graphical representation of a side elevation view of another medical probe according to the disclosed technology;

[0017] Figure 6 is according to the disclosed technology Figure 5 schematic graphical representation of detail A in;

[0018] Figure 7 is according to the disclosed technology Figure 5 schematic graphical representation of a cross-sectional view of the distal end of a medical probe, showing a portion of it cut away;

[0019] Figure 8 is Figure 5 schematic graphical representation of the external portion of the distal end of a medical probe;

[0020] Figure 9 is Figure 5 schematic graphical representation of the internal portion of the distal end of a medical probe;

[0021] Figure 10 is a schematic diagram showing according to the disclosed technology Figure 5 schematic diagram of a probe body near the Marshall vein and a guide wire inserted into the Marshall vein;

[0022] Figure 11A is a schematic diagram showing according to the disclosed technology Figure 5 schematic diagram of a probe body inserted into the Marshall vein;

[0023] Figure 11B is similar to Figure 11A schematic diagram, which shows according to the disclosed technology Figure 5 probe body further inserted into the Marshall vein;

[0024] Figure 12 is a schematic illustration representing a side view of another medical probe according to the disclosed technology;

[0025] Figure 13 shows the heart and a guidewire catheter of a medical probe inserted into the Marshall vein according to the disclosed technology Figure 12 in a schematic diagram;

[0026] Figure 14A is according to the disclosed technology Figure 12 and Figure 13 a schematic illustration representing a side view of a modified end of the guidewire catheter shown in; and

[0027] Figure 14B is according to the disclosed technology Figure 14A a schematic illustration representing detail B shown in. DETAILED DESCRIPTION

[0028] The following detailed description should be read in conjunction with the accompanying drawings, in which like numerals in different drawings represent the same elements. The drawings (not necessarily to scale) depict selected examples and are not intended to limit the scope of the disclosure. The detailed description illustrates, by way of example and not limitation, the principles of the technology disclosed in the present invention. This description will clearly enable those skilled in the art to make and use the technology disclosed in the present invention and describes several embodiments, adaptations, variations, alternative forms, and uses of the technology disclosed in the present invention, including what is presently believed to be the best mode of carrying out the technology disclosed in the present invention.

[0029] As used herein, the term "about" or "approximately" in reference to any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or components to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of values of ±20% of the recited value, e.g., "about 90%" can refer to a range of values from 71% to 110%. Additionally, as used herein, the terms "patient", "recipient", "user", and "subject" refer to any human or animal subject, and are not intended to limit the system or method to human use, but the use of the subject technology in human patients represents a preferred embodiment. Similarly, the term "proximal" refers to a position closer to the operator or physician, while "distal" refers to a position farther from the operator or physician.

[0030] As discussed herein, the vasculature of a "patient", "recipient", "user", and "subject" can be that of a human or any animal. It should be understood that the animal can be of any suitable type, including but not limited to mammals, veterinary animals, livestock animals, or pet animals, etc. For example, the animal can be an experimental animal (e.g., rats, dogs, pigs, monkeys, etc.) specifically selected to have certain characteristics similar to humans. It should be understood that the subject can be, for example, any suitable human patient.

[0031] As discussed herein, an "operator" can include a doctor, surgeon, technician, scientist, or any other individual or delivery instrument associated with delivering a multi-electrode catheter for treating drug-refractory atrial fibrillation to a subject.

[0032] As discussed herein, when referring to the devices and corresponding systems of the present disclosure, the term "ablation" refers to components and structural features configured to reduce or prevent the generation of unstable cardiac signals in cells by using non-thermal energy (such as irreversible electroporation (IRE)), which can be interchangeably referred to as pulsed electric field (PEF) and pulsed field ablation (PFA) in the present disclosure. "Ablation" as used throughout the present disclosure, when referring to the devices and corresponding systems of the present disclosure, refers to non-thermal ablation of cardiac tissue for certain conditions, including but not limited to arrhythmia, atrial flutter ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The term "ablation" also includes known methods, devices, and systems for achieving various forms of ablation of body tissue understood by those skilled in the relevant art.

[0033] As discussed herein, the terms "bipolar" and "unipolar", when used to refer to ablation protocols, describe ablation protocols that are different in terms of current path and electric field distribution. "Bipolar" refers to an ablation protocol that utilizes the current path between two electrodes as described below, both of which are positioned at the treatment site; the current density and electric flux density at each of the two electrodes are generally approximately equal. "Unipolar" refers to an ablation protocol that utilizes the current path between two electrodes as described below, where one electrode with a high current density and high electric flux density is positioned at the treatment site, and a second electrode with a relatively low current density and low electric flux density is positioned away from the treatment site.

[0034] As discussed herein, the terms "tubular", "tube", and "shaft" should be understood broadly and are not limited to structures that are a perfect cylinder or have a completely circular cross-section or a uniform cross-section along their entire length. For example, a tubular / shaft structure is typically illustrated as a structure that is substantially a perfect cylinder. However, without departing from the scope of the present disclosure, the tubular / shaft structure can have a tapered or curved outer surface.

[0035] The present disclosure relates to systems, methods, or uses, and devices for position tracking and mapping within the coronary sinus and / or the vein of Marshall (VOM), and irreversible electroporation (IRE) ablation of cardiac tissue to treat arrhythmias. Ablation energy is typically delivered to cardiac tissue (e.g., LOM) by an end portion of a catheter, which can be advanced along the tissue to be ablated. Some example catheters include a three-dimensional structure at the end portion and are configured to deliver ablation energy from various electrodes positioned on the three-dimensional structure. Visualization of ablation procedures incorporating such example catheters can be enabled without the use of fluoroscopy.

[0036] The application of thermal techniques such as radiofrequency (RF) energy and cryoablation for ablation of cardiac tissue in a malfunctioning heart is a well-known procedure. Generally, in order to successfully ablate using a thermal technique, cardiac electrode potentials need to be measured at various locations in the myocardium. Additionally, temperature measurements during ablation provide data that enables achievement of ablation efficacy. Generally, for ablation procedures using thermal ablation, electrode potentials and temperatures are measured before, during, and after actual ablation. The RF method can have risks that may result in tissue charring, burns, steam pops, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulas. Cryoablation is an alternative to RF ablation, which can reduce some of the thermal risks associated with RF ablation. However, compared to RF ablation, manipulation of cryoablation devices and selective application of cryoablation is generally more challenging; thus, cryoablation is not feasible in certain anatomical geometries accessible by electroablation devices.

[0037] The present disclosure may include electrodes configured for irreversible electroporation (IRE), RF ablation, and / or cryoablation. Throughout the present disclosure, IRE may be interchangeably referred to as pulsed electric field (PEF) ablation and pulsed field ablation (PFA). As discussed in the present disclosure, IRE is a non-thermal cell death technique that can be used for ablation of atrial arrhythmias. To ablate using IRE / PEF, biphasic voltage pulses are applied to disrupt the cellular structure of the myocardium. The biphasic pulses are non-sinusoidal and can be tuned based on the electrophysiology of the cells to target the cells. In contrast, to ablate using RF, a sinusoidal voltage waveform is applied to generate heat at the treatment area, heating all cells indiscriminately in the treatment area. Thus, IRE has the ability to avoid adjacent thermosensitive structures or tissues, which would be beneficial in reducing possible complications known to be affected by ablation or dissection modalities. Additionally or alternatively, monophasic pulses may be used.

[0038] Electroporation can be induced by applying a pulsed electric field across a biological cell to cause pores to be generated reversibly (temporarily) or irreversibly (permanently) in the cell membrane. When a pulsed electric field is applied, the cell has a transmembrane electrostatic potential that is elevated above the static potential. When the transmembrane electrostatic potential remains below the threshold potential, the electroporation is reversible, meaning that the pores can close when the applied pulsed electric field is removed, and the cell can repair itself and survive. If the transmembrane electrostatic potential is elevated above the threshold potential, the electroporation is irreversible, and the cell becomes permanently permeable. Consequently, the cell dies due to the loss of homeostasis and typically dies by apoptosis. Generally, different types of cells have different threshold potentials. For example, cardiac cells have a threshold potential of approximately 500 V / cm, while for bone, the threshold potential is 3000 V / cm. These differences in threshold potential allow IRE to selectively target tissues based on the threshold potential.

[0039] The techniques of the present disclosure include systems and methods for applying an electrical signal from a catheter electrode positioned near myocardial tissue to generate ablation energy to ablate the myocardial tissue. In some examples, the systems and methods can effectively ablate the target tissue by inducing irreversible electroporation. In some examples, the systems and methods can effectively induce reversible electroporation as part of a diagnostic procedure. Reversible electroporation occurs when the electricity applied using the electrode is below the electric field threshold of the target tissue that allows the cell to repair. Reversible electroporation does not kill the cell but allows the physician to view the effect of the reversible electroporation on the electrically activated signals near the target location. Exemplary systems and methods for reversible electroporation are disclosed in U.S. Patent Publication 2021 / 0162210, the entire content of which is incorporated herein by reference.

[0040] The pulsed electric field and its efficacy in inducing 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 geometry, etc. The examples presented herein generally include physical parameters suitable for effectively inducing reversible electroporation and / or irreversible electroporation. The biphasic pulse parameters of the electrical signal can include voltage amplitude, pulse duration, pulse interphase delay, interpulse delay, total application time, delivered energy, etc. In some examples, the parameters of the electrical signal can be adjusted to induce both reversible and irreversible electroporation given the same physical parameters. Examples of various ablation systems and methods including IRE are presented in U.S. Patent Publications 2021 / 0169550A1, 2021 / 0169567A1, 2021 / 0169568A1, 2021 / 0161592A1, 2021 / 0196372A1, 2021 / 0177503A1, and 2021 / 0186604A1, the entire content of each of these patent publications being incorporated herein by reference.

[0041] ReferenceFigure 1 , which shows an exemplary catheter-based electrophysiological mapping and ablation system 10. System 10 includes a plurality of catheters that are inserted by a physician 24 through the vasculature of a patient 23 via the skin into the chambers or vascular structures of the heart 12. Generally, the probe 14 is used to sense or ablate hard-to-reach parts of the heart, and by way of example, the sensing of anatomical signals and / or ablation of a part of the LOM of the heart 12 is described herein. However, it should be understood that the medical probe 22 can be used for other therapeutic and / or diagnostic purposes in the heart or other body organs with necessary modifications. 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 probe configured for sensing IEGM, such as catheter 14, is illustrated herein. The physician 24 places the distal end of the catheter 14 in contact with the heart wall for sensing a target site in the heart 12. For ablation, the physician 24 would similarly bring the distal end of the ablation catheter to the target site for ablation.

[0042] Catheter 14 is an exemplary catheter that includes one (and preferably a plurality) of electrodes 26 optionally distributed on the probe body and configured to sense IEGM signals. Catheter 14 may additionally include one or more position sensors embedded in or near the distal end 28 for tracking the position and orientation of the distal end 28. Optionally and preferably, the position sensor is a magnetic-based position sensor (discussed in more detail below).

[0043] The magnetic-based position sensor can operate in conjunction with a positioning pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predetermined workspace. The real-time position of the distal end 28 of the catheter 14 can be tracked based on the magnetic field generated by the positioning pad 25 and sensed by the magnetic-based position sensor. Details of magnetic-based position sensing techniques are described in U.S. Pat. Nos. 5,391,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, 6,892,091, each of which is incorporated herein by reference.

[0044] System 10 includes one or more electrode patches 38 that are positioned to contact the skin of patient 23 to establish a position reference for impedance-based tracking of positioning pad 25 and electrodes 26. For impedance-based tracking, current is directed toward electrodes 26 and sensed at the electrode-skin patches 38 such that the position of each electrode can be triangulated via the electrode patches 38. Details of impedance-based position tracking techniques are described in U.S. 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.

[0045] Recorder 11 displays an electrogram 21 captured using body surface ECG electrodes 18 and an intracardiac electrogram (IEGM) captured using electrodes 26 of catheter 14. Recorder 11 may include pacing capabilities for pacing the heart rhythm and / or may be electrically connected to an independent pacemaker.

[0046] System 10 may include an ablation energy generator 50 that is adapted to conduct ablation energy to one or more electrodes at the distal end of a catheter configured for ablation. The energy generated by ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy or pulsed field ablation (PFA) energy (including monopolar or bipolar high voltage DC pulses that can be used to effect irreversible electroporation (IRE)), or combinations thereof.

[0047] Patient interface unit (PIU) 30 is an interface configured to establish electrical connectivity between the catheter, electrophysiology equipment, power supply, and workstation 55 for controlling the operation of System 10. The electrophysiology equipment of System 10 may include, for example, multiple catheters, positioning pad 25, body surface ECG electrodes 18, electrode patches 38, ablation energy generator 50, and recorder 11. Optionally and preferably, PIU 30 further includes processing capabilities for performing real-time calculations of the position of the catheter and for performing ECG calculations.

[0048] Workstation 55 includes a memory, a processor unit with a memory or storage device loaded with appropriate operating software, and user interface capabilities. Workstation 55 may provide a plurality of functions, optionally including: (1) performing three-dimensional (3D) modeling of the endocardial anatomy and rendering a model or anatomical map 20 for display on display device 27; (2) displaying, on display device 27, an activation sequence (or other data) compiled from the recorded electrograms 21 as representative visual markers or images superimposed on the rendered anatomical map 20; (3) displaying the real-time position and orientation of multiple catheters within the heart chambers; and (5) displaying on display device 27 sites of interest, such as where ablation energy has been applied. A commercial product embodying the elements of System 10 may be CARTOTM The 3System is purchased from Biosense Webster, Inc., 31 Technology Drive, Suite 200, Irvine, CA 92618, USA.

[0049] Figure 2 FIG. 5 is a schematic illustration showing a perspective view of a medical device 14 having an electrode 26. The medical device 14 includes a handle 1000 and a probe body 100 that extends longitudinally from the handle 1000 along a longitudinal axis 60 and includes a distal end 28. The probe body 100 in the presently described example includes an elongated flexible shaft 102. The shaft 102 may be formed of a flexible, biocompatible, electrically insulating material such as a polyamide-polyether (Pebax) copolymer, polyethylene terephthalate (PET), polyurethane, polyimide, parylene, silicone, and the like. In some examples, the insulating material may comprise a biocompatible polymer including, but not limited to: polyetheretherketone (PEEK), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) copolymer (PLGA), polycaprolactone (PCL), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly-L-lactide, polydioxanone, polycarbonate, and polyanhydride, where the ratio of certain polymers is selected to control the degree of the inflammatory response.

[0050] In the examples described herein, the electrode 26 may be used to determine the position of the probe body 100 and / or measure physiological / anatomical properties, such as local surface potential at corresponding positions on tissue in the heart 12. In addition to using the electrode 26 to determine the position and / or measure anatomical signals, the electrode 26 may also be configured to deliver ablation energy (IRE and / or RF) to tissue in the heart 12. In some examples, the electrode assembly 26 may include a dome electrode 26A at the distal end of the probe body 100. When the lead electrode 26 is located at the distal end of the probe body 100, the dome electrode 26A may assist the physician 24 in navigating the catheter 14. The signals collected may be used to assist in guiding the catheter 14, generally and especially in the absence of imaging.

[0051] Examples of materials ideally suited for forming the electrode 26 include gold, platinum, and palladium (and their corresponding alloys). These materials also have high thermal conductivity, which allows the minimum heat generated on the tissue (i.e., by 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 on the inner side of the ridge), and then to the blood pool in the heart 12.

[0052] Figure 3is a schematic illustration showing a cross-sectional side view of the probe body 100. Embedded within the probe body 100 are a plurality of coils 33 disposed at predetermined locations along a longitudinal axis 60. Each coil 33 is configured to generate a current when subjected to a magnetic field. In some examples, each coil 33 may include a single-axis sensor (SAS). The coil 33 may include a conductive material wound cylindrically into a coil or a flat spiral coil formed as a planar flexible circuit. The coil 33 may include electrical leads for conducting the current induced on each coil 33 to the patient interface unit 30. As will be appreciated, by attaching the plurality of coils 33 to the distal end 28 of the probe body 100, the position of the distal end can be detected. In this way, the physician 24 can more accurately determine the position of the distal end of the probe body before using the probe body 100 to sense anatomical signals and / or apply ablation energy to tissue in, for example, the VOM 42.

[0053] Figure 4 is a schematic illustration showing the coronary sinus 40, the VOM 42, the LOM 44, and the great cardiac vein 48, where the probe body 100 is inserted into the VOM 42. By way of example, the following description assumes that the target region 46 of the LOM 154 is to be mapped / sensed and / or ablated. It should be noted that, for purposes of schematic illustration, the coils 33 are shown as dashed lines in this figure.

[0054] In an initial step, the physician 24 inserts the probe body 100 into the subject and then navigates the probe body 100 into the heart 12. Within the heart 12, the probe body is navigated via the coronary sinus 40 into the LOM 44 until the distal end of the probe body 100 is within the vicinity of the target region 46. The distal end of the probe body 100 can be manipulated by, for example, one or more pull wires integrated therewith. Typically, the processor 55 uses signals from the sensors 33 or from the electrodes 26 to display an icon representing the position of the distal end 28 of the probe body 100 on the mapping diagram 20 to assist the physician 24 in navigation. Additionally, the physician 24 can use fluoroscopy to assist in navigation.

[0055] In the mapping and / or sensing step, the position of the electrodes 26 relative to the target region 46 can be verified by the current tracking module of the PIU 30 using the impedance and / or current between the electrodes 26 and the patches 38. Additionally, the position of the electrodes can be verified by fluoroscopy. Once it has been determined that the electrodes 26 are properly positioned relative to the target region 46, the medical probe body 100 is manipulated so that one or more of the electrodes 26 contact the endocardial tissue (e.g., the endocardial surface). The electrodes 26 generate a potential gradient signal in response to the sensed electric potential, also referred to herein as an electrical signal. In some examples, the sensed electrical signal indicates the direction and propagation speed of a wavefront caused by an anatomical signal such as an electrocardiogram (ECG) signal in the heart 12.

[0056] During the ablation step, physician 24 operates processor 55 and ablation energy generator 50 to supply current to electrode 26. If there are two or more electrodes 26, the supplied current can be bipolar, i.e., the current can flow between the electrodes 26 to deliver ablation energy to the tissue. Alternatively, the supplied ablation energy can be monopolar, i.e., the current can be applied between one of the electrodes 26 and a return electrode connected to generator 50. The return electrode can be disposed outside patient 23. For example, the return electrode can include a patch (e.g., electrode patch 38, etc.) coupled to the patient's body.

[0057] In some examples, an RF sinusoidal (alternating current) current is supplied to electrode 26 such that RF ablation of the tissue is performed. Alternatively, a pulsed current (direct current) can be supplied to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is supplied to perform PFA, monopolar ablation energy can be provided by a direct current flowing between electrode 26 on elongate shaft 202 and electrode patch 38 or patch. Additionally, bipolar ablation energy can be provided by a direct current flowing between electrode 26 on elongate shaft 202 itself and / or another catheter 14A (e.g., a focal catheter or a multi-electrode catheter) within left atrium 12A (see Figure 1 ).

[0058] Once physician 24 has completed mapping and / or ablation, the physician can withdraw the medical probe body 100 from patient 23. The foregoing method describes the mapping and / or ablation of one target area. Of course, the specific implementation of the techniques described in the present invention is not limited to the sensing and / or ablation of a single area, but can be used to map / sense and / or ablate two or more separate areas during a single ablation procedure. For example, if there is a second target area closer to coronary sinus 40 than target area 46, electrode 26 can be moved near the second area, and electrode 26 can be pushed to contact the second area in preparation for sensing anatomical signals and / or ablating the area.

[0059] Figure 5 is a schematic illustrative representation of a side view of another medical probe 14 designed according to the techniques disclosed in the present invention. Figure 6 is Figure 5 a schematic illustrative representation of a detailed view of detail A. Figure 7 is Figure 5 a schematic illustrative representation of a cross-sectional view of the distal end of medical probe 14, showing a portion cut away. Figure 8 is Figure 5 a schematic illustrative representation of the external portion of the distal end of medical probe 14. Figure 9 is Figure 5Schematic illustration of the interior portion of the distal end of the medical probe 14.

[0060] See Figures 5 to 9 , the medical device 14 includes a probe body 200 that extends parallel to or coaxially with a longitudinal axis 60 and includes a distal end 28. The probe body 200 is connected to a handle 1000. The handle 1000 may also be connected to an energy connector housing 2000 through which energy (such as PFA) can be directed for ablation purposes. In the presently described example, the probe body 200 includes an elongate flexible shaft 202, defines a lumen 204, and is sized to be inserted into the VOM 46. By way of example, the outer diameter of the shaft 202 can be approximately 3Fr to 4Fr, for example 0.04 inches to 0.05 inches.

[0061] Specifically, as Figure 7 shown, the elongate shaft 202 includes a tubular outer wall 206 and a tubular lumen wall 208 that are coaxial with each other. The lumen wall 208 is nested within the outer wall 206 and at least partially defines the lumen 204. The outer wall 206 and the lumen wall 208 are attached to a connecting shaft 210 that extends into the handle 1000. The outer wall 206, the lumen wall 208, and the connecting shaft 210 can each be formed of a flexible, biocompatible, electrically insulating material such as a polyamide-polyether (Pebax) copolymer, polyethylene terephthalate (PET), polyurethane, polyimide, parylene, silicone, etc. In some examples, the insulating material may comprise a biocompatible polymer including, but not limited to: polyetheretherketone (PEEK), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) copolymer (PLGA), polycaprolactone (PCL), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly-L-lactide, polydioxanone, polycarbonate, and polyanhydrides, where the ratio of certain polymers is selected to control the degree of the inflammatory response.

[0062] As Figures 5 to 7 shown, a guide wire 220 extends through a Luer hub 222 in the handle 1000, through the lumen 204, and out of the distal end 202A of the elongate shaft 202A. To fit through the lumen 204, the guide wire 220 can have a very small diameter, such as a diameter in the range of 0.01 inches and 0.02 inches. It should be understood that intracardiac navigation to difficult-to-reach sites such as the LOM 44 is complex because the guide wire 220 has to bend around one or more acute angles. For example, to reach the LOM 44, the guide wire 220 may need to pass through the inferior vena cava, the right atrium, and the coronary sinus 40. Complex navigation is facilitated by constructing the guide wire 220 to be extremely thin and to be flexible and non-kinking.

[0063] Similar to the foregoing example, the elongate shaft 202 includes an electrode 26 attached thereto at its distal end. Specifically, the electrode 26 can be designed as an annular electrode 26 that extends around the outer wall 208 and is coaxial with and spaced along the longitudinal axis 60. The outer diameter of the annular electrode 26 can be similar to the outer diameter of the elongate shaft 202 (e.g., between 0.04 inches and 0.05 inches), such that they are substantially flush with or slightly protrude from the elongate shaft 202. The most distal electrode 26A can be designed as an annular electrode or a dome electrode. When the lead electrode 26 is located at the distal end of the elongate shaft, the most distal electrode 26A can assist the physician 24 in navigating the catheter 14. The signals collected can be used to assist in guiding the catheter 14, generally and particularly in the absence of imaging. As described above, in the examples described herein, the electrode 26 can be used to determine the position of the probe body 200 and / or measure physiological / anatomical properties, such as the local surface potential at corresponding locations on tissue in the heart 12. In addition to using the electrode 26 to determine the position and / or measure anatomical signals, the electrode 26 can also be configured to deliver ablation energy (IRE and / or RF) to tissue in the heart 12.

[0064] In some examples, approximately eight to ten electrodes 26 can be disposed on the elongate shaft 202, these electrodes having a predetermined spacing relative to each other along the longitudinal axis 60. Specifically referring to Figure 8 , the presently described example includes ten electrodes 26, each electrode 26 having a height H1 and a predetermined spacing length L1 to L10 relative to the distal end 202A of the elongate shaft 202. By way of example only and not limiting the scope of the present disclosure, the electrode 26 can have a height H1 of approximately 1 mm and a spacing of 2 mm from each other (e.g., L1, which is the position of the distal end of the most distal electrode 26, is approximately flush with the distal end 202A, i.e., 0 mm from the distal end; L2, which is the distal end of the second most distal electrode 26, is approximately 2 mm from the distal end; L3, which is the distal end of the third most distal electrode 26, is approximately 4 mm from the distal end, and so on). In addition, the outer wall 206 has a total length LT. In some examples, LT is approximately 130 mm.

[0065] In addition to the above, as Figure 7 and Figure 9As shown, multiple (such as three) coils 33 are embedded within the probe body 200, and these coils are disposed at predetermined positions along the longitudinal axis 60. Each coil 33 is configured to generate a current when subjected to a magnetic field. In some examples, each coil 33 may include a single-axis sensor (SAS). The coil 33 may include a conductive material wound into a coil or a coil formed as a flexible circuit. The coil 33 may include electrical leads for conducting the current induced on each coil 33 to the patient interface unit 30. As will be appreciated, by attaching the multiple coils 33 to the distal end 28 of the probe body 100, the position of the distal end can be detected. In this way, the physician 24 can more accurately determine the position of the distal end of the probe body before using the probe body 100 to sense anatomical signals and / or apply ablation energy to tissue in, for example, the VOM 42.

[0066] Continuing to refer Figure 7 and Figure 9 , each coil 33 is mounted on the lumen wall 208 such that each coil 33 is disposed between the outer wall 206 and the lumen wall 208 (i.e., sandwiched therebetween). As with the electrodes 26, the distal end of each coil 33 has a predetermined position (L11, L12, and L13, respectively) relative to the distal end 202A of the elongate shaft 202. Specifically, for example, the distal end L11 of the most distal coil 33 is approximately flush with the distal end 202A of the elongate shaft 202 (i.e., approximately 0 millimeters from it), the distal end L12 of the middle coil 33 is approximately 24 millimeters away from the distal end 202A, and the distal end L13 of the most proximal coil 33 is approximately 36 millimeters away from the distal end 202A. Thus, it should be understood that in the case of the foregoing exemplary predetermined positions, the most distal coil 33 overlaps the most distal electrode 26 along the longitudinal axis 60, whereas the middle and most proximal coils 33 are sufficiently spaced from the distal end 202A of the elongate shaft 202 such that they do not overlap either of the electrodes 26, and both are positioned along the longitudinal axis 60 closer to the distal end than all of the electrodes 26.

[0067] Of course, other coil 33 configurations may also be appropriate. For example, two coils 33 (instead of three) may be sufficient to track the position of the distal end 28. As another example, some or all of the coils 33 may be positioned such that they overlap the positions of the electrodes 26 (similar to as Figure 4 depicted), rather than positioning the middle and most proximal coils 33 such that they do not overlap either of the electrodes 26 along the longitudinal axis 60.

[0068] Additionally, in some examples, the elongate shaft 202 may further include an expandable balloon 230. As Figure 8As shown (with balloon 230 not inflated in the figure), for purposes discussed in more detail below, balloon 230 is disposed closer to handle 1000 than some or all of electrodes 26, and the balloon can be inflated via a balloon lumen extending through elongate shaft 202.

[0069] Figure 10 is a schematic illustration showing coronary sinus 40, VOM 42, LOM 44, and great cardiac vein 48, where probe body 200 is adjacent to VOM 42 and guidewire 220 is inserted into VOM 42. Figure 11A is a schematic illustration showing probe body 200 inserted into VOM 42. Figure 11B is a schematic illustration showing Figure 11A probe body 200 inserted further into VOM 42 than the depiction of. By way of example, the following description assumes that target region 46 of LOM 154 is to be mapped / sensed and / or ablated. Of course, it should be understood that target region 46 can have various sizes and forms and need not be as depicted in the figures. It should be noted that for illustrative purposes, lumen 204 and coil 33 are shown in dashed lines in these figures.

[0070] In an initial step, physician 24 inserts probe body 200 and guidewire 220 into a subject and then navigates guidewire 220 into heart 12. Within heart 12, probe body 200 and guidewire 220 are navigated via coronary sinus 40 until the distal end of probe body 200 is within the vicinity of the entrance of VOM 42 (e.g., as Figure 10 shown). The position of the entrance of VOM 42 can be determined by physician 24 using signals received from one or more of coil 33 and / or electrodes 26. In this manner, processor 55 uses those signals from sensor 33 or from electrodes 26 to display an icon representing the position of distal tip 28 of probe body 200 on mapping diagram 20 to assist physician 24 in navigation. Additionally, physician 24 can use fluoroscopy to aid in navigation.

[0071] In the guidewire 220 insertion step, and as Figure 10 shown, once the entrance of VOM 42 has been located, guidewire 220 extends distally out of lumen 204 and is guided into VOM 42. Guidewire 220 reduces the complexity of accessing VOM 42, which, as described above, is difficult to access.

[0072] In the probe body 200 insertion step, and as Figure 11AAs shown, once the guide wire 220 has been guided into the VOM 42, the distal end 28 of the elongate shaft 202 slides along the guide wire 220 into the VOM 42 until it reaches its target region 46. Additionally or alternatively, the elongate shaft 202 can be further inserted into the VOM 42, as Figure 11B shown.

[0073] In the balloon inflation step, and as Figure 11A and Figure 11B shown, the balloon 230 can optionally be inflated to occlude the coronary sinus 40 and / or the great cardiac vein 48 and / or the VOM 42, depending on the placement. As Figure 11A shown, the balloon 230 occludes the coronary sinus 40. The elongate shaft 202 is further inserted into the VOM 42, as Figure 11B shown, positioning the balloon 230 such that it can be inflated to occlude the VOM 42. This helps to hold the probe body 200 in the desired position and also prevents fluid flow in the occluded vessel in the case where an external fluid (e.g., ethanol or saline) is injected into the vessel via the lumen 204, which will be discussed in more detail below. Due to its purpose (position holding and / or occlusion), a complex design is not required (e.g., electrodes are not positioned on the balloon 230 as it is not directly used for mapping and / or ablation).

[0074] In the mapping and / or sensing step, the position of the electrode 26 relative to the target region 46 can be verified by the current tracking module of the PIU 30 using the impedance and / or current between the electrode 26 and the patch 38 and / or (alternatively) using the coil 33. Additionally, the position of the electrode can be verified by fluoroscopy. Once it has been determined that the electrode 26 is properly positioned relative to the target region 46 (e.g., by subjecting each coil to a magnetic field to generate a corresponding current in each coil 33, which indicates the position of the corresponding coil 33), the medical probe body 200 is manipulated to bring one or more of the electrodes 26 into contact with the endocardial tissue (e.g., the inner heart surface). The electrode 26 generates a potential gradient signal in response to the sensed electrical potential, also referred to herein as an electrical signal. In some examples, the sensed electrical signal indicates at least one characteristic of the anatomical signal, such as the direction and propagation speed of the wavefront caused by the anatomical signal (such as an electrocardiogram (ECG) signal in the heart 12).

[0075] During the ablation step, physician 24 operates processor 55 and ablation energy generator 50 to supply current to electrode 26. If there are two or more electrodes 26, the supplied current can be bipolar, i.e., the current can flow between electrodes 26 to deliver ablation energy to the tissue. Alternatively (e.g., if there is only one electrode 26), the supplied ablation energy can be monopolar, i.e., the current can be applied between one of electrodes 26 and a return electrode connected to generator 50. The return electrode can be disposed outside patient 23. For example, the return electrode can include a patch (e.g., electrode patch 38, etc.) coupled to the patient's body.

[0076] In some examples, an RF sinusoidal (alternating current) current is supplied to electrode 26 such that RF ablation of the tissue is performed. Alternatively, a pulsed current (direct current) can be supplied to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is supplied to perform PFA, monopolar ablation energy can be provided by a direct current flowing between electrode 26 on elongate shaft 202 and electrode patch 38 or patch. Additionally, bipolar ablation energy can be provided by a direct current flowing between electrode 26 on elongate shaft 202 itself and / or another catheter 14A (e.g., a focal catheter or a multi-electrode catheter) within left atrium 12A (see Figure 1 ).

[0077] In addition to or alternatively, in some examples, lumen 204 can be used to direct ethanol through to perform chemical ablation of LOM 44. In such examples, balloon 230 proximal to electrode 26 is inflated (as described above) to occlude VOM 42, as Figure 11B shown. Figure 11A and Figure 11B depict exemplary positions in which balloon 230 can be maneuvered to occlude different vessels of heart 12. Additionally, saline can also be directed through lumen 204 to be used as a virtual electrode. The inflated balloon 230 prevents the injected fluid from discharging before ablation can be performed.

[0078] Once physician 24 has completed mapping / sensing and / or ablation, the physician can withdraw the medical probe body 200 and guide wire from patient 23. The foregoing method describes mapping / sensing and / or ablation of one target region. Of course, the specific implementation of the technology described in the present invention is not limited to sensing and / or ablation of a single region, but can be used to map / sense and / or ablate two or more separate regions (or entire vessels) during a single ablation procedure. For example, if there is a second target region closer to coronary sinus 40 than target region 46, electrode 26 can be moved near the second region and electrode 26 can be pushed to contact the second region in preparation for sensing anatomical signals and / or ablating the region.

[0079] Figure 12Schematic illustration showing a side view of another medical probe 14 designed according to the technology disclosed in the present invention. Figure 13 Schematic illustration showing the heart 12, where the elongated probe 310 (embodied as a shaft) is close to the VOM 42 and the guidewire catheter 302 is inserted into the VOM 42.

[0080] See Figure 12 , the medical device 14 includes a probe body 300 that extends parallel to or coaxially with the longitudinal axis 60 and includes a distal end 28. The probe body 200 is connected to a handle 1000 (not specifically described in this example, but it should be understood that it can take the form of the previously described handle 1000). The handle 1000 can also be connected to an energy connector housing through which energy (such as PFA) can be guided for ablation purposes.

[0081] The probe body 300 in the currently described example includes an elongated coronary sinus catheter embodied as an elongated probe 310 that extends along the longitudinal axis 60 (e.g., coaxially with the longitudinal axis). The elongated probe 310 defines a main lumen, a distal end opening ( Figure 12 on the right side), and side openings 312, and is sized to be inserted into the coronary sinus 40. By way of example, the outer diameter of the coronary sinus catheter 310 can be approximately 6Fr to 7Fr, e.g., 0.08 inches to 0.09 inches.

[0082] The elongated probe 310 includes a plurality of electrodes 26 (e.g., annular electrodes that are substantially flush with or protrude from the probe 310) connected to the elongated probe 310 along the longitudinal axis 60. The elongated probe 310 can also include a probe balloon 314 that can be inflated via a balloon lumen extending through the elongated probe 310 and will be discussed in more detail below.

[0083] As Figure 12 shown, extending through the main lumen of the elongated probe 310 along the longitudinal axis 60 (e.g., coaxially with the longitudinal axis) is a guidewire catheter 302 that is sized to be inserted into the vein of Marshall 42. In use, the guidewire catheter 302 can extend through the distal end opening ( Figure 12 ) or extend through the side opening 312 of the elongated probe 310 ( Figure 13)。Compared with the aforementioned guide wire 220, the guide wire catheter 302 has a larger outer diameter. For example, in this example, the outer diameter of the guide wire catheter 302 is approximately 0.03 inches to 0.04 inches (2Fr to 3Fr). A guide wire lumen (similarly embodied as the aforementioned lumen 204) passes through the guide wire catheter 302, and a guide wire 302A (which has a diameter of approximately 0.010 inches to 0.014 inches) passes through the guide wire lumen, which helps the guide wire catheter 302 perform intracardiac navigation and will be discussed in more detail below.

[0084] The guide wire catheter 302 includes a plurality of electrodes 26 connected thereto along the longitudinal axis 60 (e.g., annular electrodes that are substantially flush with or slightly protruding from the catheter 302). The guide wire catheter 302 may also include the most distal electrode 26A as described above. The guide wire catheter 302 may also include a guide wire balloon 304 that is disposed closer to the handle 1000 than some or all of the electrodes 26, which can be inflated via a balloon lumen that extends through the guide wire catheter 302 and will be discussed in more detail below.

[0085] The probe 310 and the guide wire catheter 302 can each be formed of a flexible, biocompatible, electrically insulating material, such as a polyamide-polyether (Pebax) copolymer, polyethylene terephthalate (PET), polyurethane, polyimide, parylene, silicone, etc. In some examples, the insulating material may comprise a biocompatible polymer, including but not limited to: polyetheretherketone (PEEK), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) copolymer (PLGA), polycaprolactone (PCL), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly-L-lactide, polydioxanone, polycarbonate, and polyanhydride, where the ratio of certain polymers is selected to control the degree of inflammatory response.

[0086] Figure 13 An exemplary use of the probe body 300 is depicted. In an initial step, the physician 24 inserts the elongated probe 310 and the guide wire catheter 302 (which is retracted into the coronary sinus catheter 310) into the subject and then navigates them into the heart 12. Inside the heart 12, the coronary sinus catheter 310 and the guide wire catheter 302 are navigated via the coronary sinus 40 until the distal end of the coronary sinus catheter 310 is inside near the entrance of the VOM 42. The position of the entrance of the VOM 42 can be determined by the physician 24 using the signals received from the electrodes 26 of the elongated probe 310 and / or the guide wire catheter 302. In this way, the processor 55 uses those signals from the electrodes 26 to display an icon representing the position of the distal end 28 of the probe body 300 on the mapping diagram 20, thereby assisting the physician 24 in navigation. Additionally, the physician 24 can use fluoroscopy to assist in navigation.

[0087] In the balloon inflation step, and asFigure 13 As shown, the probe balloon 314 can optionally be inflated to occlude the coronary sinus 40 and / or the great cardiac vein 48 depending on its placement. This helps to hold the elongate probe 310 in a desired position and also prevents fluid flow in the occluded vessel in the case where an external fluid (e.g., ethanol or saline) is injected into the vasculature via the guidewire catheter 302, which will be discussed in more detail below. Due to its purpose (position holding and / or occlusion), a complex design is not required (e.g., electrodes are not positioned on the probe balloon 314 as it is not directly used for mapping and / or ablation).

[0088] In the guidewire catheter 302 insertion step, and as Figure 13 shown, once the entrance to the VOM 42 has been located, depending on the orientation and / or position of the elongate probe 310, the guidewire 302A first extends distally out of the distal end opening or side opening 312 (in Figure 13 which the guidewire catheter 302 exits the side opening 312) and is guided into the VOM 42, after which the guidewire catheter 302 slides over the guidewire 302A. In this way, the guidewire 302A helps to maneuver the guidewire catheter 302 out of one of the openings of the elongate probe 310 and into the VOM 42, which, as described above, is difficult to access. Once the VOM 42 has been accessed, if desired, the guidewire balloon 304 can be inflated to occlude the VOM 42 and / or hold the guidewire catheter 302 in place. Due to its purpose (position holding and / or occlusion), a complex design is not required (e.g., electrodes are not positioned on the balloon 304 as it is not directly used for mapping and / or ablation).

[0089] In the mapping and / or sensing step, the position of the electrodes 26 on the guidewire catheter 302 relative to the target region can be verified by the current tracking module of the PIU 30 using the impedance and / or current between the electrodes 26 and the patch 38. Additionally, the position of the electrodes can be verified by fluoroscopy. Once it has been determined that the electrodes 26 are properly positioned relative to the target region, the guidewire catheter 302 is maneuvered so that one or more of the electrodes 26 contact the endocardial tissue (e.g., the endocardial surface). The electrodes 26 generate a potential gradient signal in response to the sensed electrical potential, also referred to herein as an electrical signal. In some examples, the sensed electrical signal indicates at least one characteristic of the anatomical signal, such as the direction and propagation speed of the wavefront caused by the anatomical signal (such as an electrocardiogram (ECG) signal in the heart 12).

[0090] During the ablation step, physician 24 operates the processor 55 and the ablation energy generator 50 to supply current to the electrodes 26 of the guidewire catheter 302. If there are two or more electrodes 26, the supplied current can be bipolar, i.e., the current can flow between the electrodes 26 to deliver ablation energy to the tissue. Alternatively, the supplied ablation energy can be monopolar, i.e., the current can be applied between one of the electrodes 26 and a return electrode connected to the generator 50. The return electrode can be disposed outside the patient 23. For example, the return electrode can include a patch (e.g., electrode patch 38, etc.) coupled to the patient's body.

[0091] In some examples, an RF sinusoidal (alternating current) current is provided to the electrodes 26 such that RF ablation of the tissue is performed. Alternatively, a pulsed current (direct current) can be provided to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is provided to perform PFA, monopolar ablation energy can be provided by a direct current flowing between the electrode 26 on the guidewire catheter 302 and the electrode patch 38 or patch. Additionally, bipolar ablation energy can be provided by a direct current flowing between the electrodes 26 on the guidewire catheter 302 itself and / or the electrodes 26 on the elongate probe 26 and / or another catheter 14A (e.g., a focal catheter or a multi-electrode catheter) within the left atrium 12A (see Figure 1 ).

[0092] In addition or alternatively, in some examples, the guidewire catheter 302 with a narrow-diameter guidewire lumen can be used to direct ethanol through to perform chemical ablation of the LOM 44. In such examples, the guidewire balloon 304 is inflated to occlude the VOM 42. Additionally, saline can also be directed through the guidewire lumen to serve as a virtual electrode. The inflated balloon 304 prevents the injected fluid from discharging before ablation can be performed.

[0093] Once physician 24 has completed mapping / sensing and / or ablation, the physician can withdraw the medical probe body 300 and the guidewire from the patient 23. The foregoing method describes mapping / sensing and / or ablation of one target region. Of course, the specific implementation of the techniques described in the present invention is not limited to sensing and / or ablation of a single region, but can be used to map / sense and / or ablate two or more separate regions (or an entire vasculature) during a single ablation procedure. For example, if there is a second target region closer to the coronary sinus 40 than the target region 46, the electrode 26 can be moved near the second region, and the electrode 26 can be pushed to contact the second region in preparation for sensing anatomical signals and / or ablating the region.

[0094] Figure 14A is regarding Figure 12 and Figure 13 a schematic illustration showing a side view of a modified form of the guidewire catheter 302 described. Figure 14B isFigure 14A A schematic illustration of a detailed view of detail B as shown. The guide wire catheter 302 depicted in these figures is the same as previously described, except that the guide wire 302A can be replaced by or further provided with anti-trauma material 302B at the distal end of the guide wire catheter 302, rather than defining a guide wire lumen therethrough, and this anti-trauma material 302B serves as the guide wire tip.

[0095] The disclosed techniques described herein can be further understood in accordance with the following terms:

[0096] Clause 1. A medical probe, the medical probe comprising: an elongate shaft extending along a longitudinal axis and sized to be inserted into the Marshall vein, the elongate shaft including a distal end and defining a lumen; a guide wire extending through the lumen; a plurality of coils connected to the distal end along the longitudinal axis, each coil configured to generate a current when subjected to a magnetic field, the current indicating the position of the corresponding coil; and a plurality of electrodes connected to the distal end along the longitudinal axis, each electrode configured to: (i) sense an anatomical signal in the Marshall vein and provide an electrical signal indicative of the anatomical signal, or (ii) deliver ablation energy to a target tissue region adjacent to the Marshall vein.

[0097] Clause 2. The medical probe according to Clause 1, wherein the elongate shaft is coaxial with the longitudinal axis.

[0098] Clause 3. The medical probe according to any one of Clauses 1 to 2, each electrode including a ring electrode, the ring electrode including an electrode axis coaxial with the longitudinal axis.

[0099] Clause 4. The medical probe according to any one of Clauses 1 to 2, the plurality of electrodes further including a dome electrode connected to the distal end of the distal end portion.

[0100] Clause 5. The medical probe according to any one of Clauses 1 to 2, the plurality of electrodes including eight to ten ring electrodes positioned along the longitudinal axis at increments of approximately two millimeters from the distal end of the distal end portion relative to each other.

[0101] Clause 6. The medical probe according to any one of Clauses 1 to 5, a first coil of the plurality of coils being disposed within the distal end and positioned to overlap the most distal electrode of the plurality of electrodes along the longitudinal axis.

[0102] Clause 7. The medical probe according to Clause 6, wherein the plurality of coils further includes a second coil and a third coil, and the second coil and the third coil are positioned away from the distal end of the distal end such that the second coil and the third coil do not overlap with each of the plurality of electrodes.

[0103] Clause 8. The medical probe according to any one of Clauses 1 to 7, wherein the elongate shaft includes an outer wall and a lumen wall defining the lumen.

[0104] Clause 9. The medical probe according to Clause 8, wherein each coil is disposed between the outer wall and the lumen wall.

[0105] Clause 10. The medical probe according to any one of Clauses 1 to 9, wherein the outer diameter of the elongate shaft is between approximately 0.04 inches and 0.05 inches.

[0106] Clause 11. The medical probe according to any one of Clauses 1 to 10, wherein each coil includes a uniaxial sensor selected from the group consisting of a flat spiral coil, a cylindrical coil, or a combination thereof.

[0107] Clause 12. The medical probe according to any one of Clauses 1 to 11, wherein the diameter of the guide wire is between approximately 0.01 inches and 0.02 inches.

[0108] Clause 13. The medical probe according to any one of Clauses 1 to 12, wherein each electrode is configured to: (i) sense the anatomical signal in the Marshall vein and provide the electrical signal indicative of the anatomical signal, and (ii) deliver the ablation energy to the target tissue region adjacent to the Marshall vein.

[0109] Clause 14. A method for navigating a medical probe to the Marshall vein, the method comprising: inserting a guide wire through the coronary sinus into the Marshall vein; sliding an elongate shaft that extends along a longitudinal axis over the guide wire, through the coronary sinus, and into the Marshall vein, the elongate shaft including a distal end to which a plurality of coils and a plurality of electrodes are connected; generating a respective current in each of the plurality of coils by subjecting each coil to a magnetic field, the current indicative of the position of the respective coil; positioning the distal end within the Marshall vein; sensing an anatomical signal in the Marshall vein using at least one of the plurality of electrodes; and providing an electrical signal indicative of the anatomical signal from the at least one electrode.

[0110] Clause 15. The method according to Clause 14, wherein the anatomical signal includes an electrocardiogram signal.

[0111] Clause 16. The method according to any one of Clauses 14 to 15, the method further comprising: delivering ablation energy to a target tissue region adjacent to the Marshall vein.

[0112] Clause 17. The method according to Clause 16, the ablation energy comprising monopolar ablation energy, the monopolar ablation energy being delivered by guiding a direct current between at least one of the plurality of electrodes and an electrode patch.

[0113] Clause 18. The method according to Clause 16, the ablation energy comprising bipolar ablation energy, the bipolar ablation energy being delivered by guiding a direct current in a manner selected from: guiding a direct current between at least one of the plurality of electrodes and another of the plurality of electrodes, guiding a direct current between at least one of the plurality of electrodes and a catheter positioned within the atrium, and combinations thereof.

[0114] Clause 19. A system, the system comprising: a medical probe, the medical probe comprising: a slender shaft extending along a longitudinal axis and sized to be inserted into the Marshall vein, the slender shaft including a distal end and defining a lumen therethrough; a guide wire extending through the lumen; a plurality of coils connected to the distal end along the longitudinal axis, each coil configured to generate a current when subjected to a magnetic field, the current indicating the position of the respective coil; and a plurality of electrodes connected to the distal end along the longitudinal axis, each electrode configured to: (i) sense an anatomical signal in the Marshall vein and provide an electrical signal indicative of the anatomical signal, or (ii) deliver ablation energy to a target tissue region adjacent to the Marshall vein; and a processor configured to estimate the position of the distal end based on the generated current, and (i) estimate at least one characteristic of the anatomical signal based on the electrical signal, or (ii) provide a signal to deliver the ablation energy to the electrodes.

[0115] Clause 20. The system according to Clause 19, the slender shaft being coaxial with the longitudinal axis.

[0116] Clause 21. The system according to any one of Clauses 19 to 20, each electrode comprising an annular electrode having an electrode axis coaxial with the longitudinal axis.

[0117] Clause 22. The system according to any one of Clauses 19 to 21, the system further comprising a dome electrode connected to the distal end of the distal end portion.

[0118] Clause 23. In the system according to any one of Clauses 19 to 22, each coil is disposed within the distal end and positioned to overlap a corresponding one of the plurality of electrodes along the longitudinal axis.

[0119] Clause 24. In the system according to Clause 23, the elongate shaft includes an outer wall and a lumen wall defining the lumen, and each coil is disposed between the outer wall and the lumen wall.

[0120] Clause 25. In the system according to any one of Clauses 19 to 24, the outer diameter of the elongate shaft is between approximately 0.04 inches and 0.05 inches.

[0121] Clause 26. In the system according to any one of Clauses 19 to 25, each coil includes a uniaxial sensor.

[0122] Clause 27. In the system according to any one of Clauses 19 to 26, the diameter of the guide wire is between approximately 0.01 inches and 0.02 inches.

[0123] Clause 28. A system comprising: an elongate probe extending along a longitudinal axis and sized to be inserted into the coronary sinus, the elongate catheter shaft including an opening; a guide wire catheter extending along the longitudinal axis through the opening and sized to be inserted into the vein of Marshall; a first plurality of electrodes connected to the elongate probe along the longitudinal axis; and a second plurality of electrodes connected to the guide wire catheter along the longitudinal axis, each electrode of the first plurality of electrodes and the second plurality of electrodes being configured to: (i) generate a current indicative of the position of the corresponding electrode, and (ii) sense an anatomical signal of tissue and provide an electrical signal indicative of the anatomical signal.

[0124] Clause 29. In the system according to Clause 28, each electrode is further configured to deliver ablation energy to a target tissue region adjacent to the vein of Marshall.

[0125] Clause 30. In the system according to any one of Clauses 28 to 29, the opening is located at the distal end of the elongate probe.

[0126] Clause 31. In the system according to any one of Clauses 28 to 29, the opening is spaced apart from the distal end of the elongate probe.

[0127] Clause 32. In the system according to any one of Clauses 28 to 31, the system further includes an inflatable probe balloon connected to the elongate probe.

[0128] Clause 33. The system according to any one of Clauses 28 to 32, the system further comprising an inflatable guidewire balloon, the inflatable guidewire balloon being connected to the guidewire catheter near the second plurality of electrodes.

[0129] Clause 34. The system according to any one of Clauses 28 to 33, the outer diameter of the guidewire catheter being about 0.03 inches to 0.04 inches.

[0130] Clause 35. The system according to any one of Clauses 28 to 34, the outer diameter of the elongate probe being about 0.08 inches to 0.09 inches.

[0131] Clause 36. The system according to any one of Clauses 28 to 35, the system further comprising a guidewire, and the guidewire catheter defining a guidewire lumen through which the guidewire extends, the guidewire extending through the guidewire lumen.

[0132] Clause 37. The system according to any one of Clauses 28 to 36, the elongate probe and the guidewire being coaxial with the longitudinal axis.

[0133] Clause 38. A method for navigating a medical probe to the Marshall vein, the method comprising: inserting an elongate probe extending along a longitudinal axis into the coronary sinus, the elongate probe defining an opening and comprising a first plurality of electrodes; sliding a guidewire catheter through the elongate probe and out of the opening of the elongate probe into the Marshall vein, the guidewire catheter comprising a second plurality of electrodes; generating a respective current in each of the first plurality of electrodes and the second plurality of electrodes, the respective current indicating the position of each respective electrode; sensing an anatomical signal in the Marshall vein using at least one of the second plurality of electrodes; and providing an electrical signal indicative of the anatomical signal from at least one of the second plurality of electrodes.

[0134] Clause 39. The method according to Clause 38, the anatomical signal comprising an electrocardiogram signal.

[0135] Clause 40. The method according to any one of Clauses 38 to 39, the method further comprising: delivering ablation energy to a target tissue region near the Marshall vein.

[0136] Clause 41. The method according to Clause 40, the ablation energy comprising monopolar ablation energy, the monopolar ablation energy being delivered by guiding a direct current between at least one of the second plurality of electrodes and an electrode patch.

[0137] Clause 42. In the method according to Clause 40, the ablation energy includes bipolar ablation energy, and the bipolar ablation energy is delivered by directing a direct current in a manner selected from: directing a direct current between at least one electrode of the second plurality of electrodes and another electrode of the second plurality of electrodes or the first plurality of electrodes, directing a direct current between at least one electrode of the second plurality of electrodes and a catheter positioned within the atrium, and combinations thereof.

[0138] The above embodiments are cited by way of example, and the technology disclosed by the present invention is not limited to the content specifically shown and described above. On the contrary, the scope of the technology disclosed by the present invention includes combinations and sub - combinations of the various features described above, as well as their variations and modifications, which will occur to those skilled in the art upon reading the above description and which are not disclosed in the prior art.

Claims

1. A medical probe, comprising: an elongated shaft extending along a longitudinal axis and sized to be inserted into the vein of Marshall, the elongated shaft including a distal tip and defining a lumen; a guidewire extending through the lumen; a plurality of coils coupled to the distal tip along the longitudinal axis, each coil configured to generate a current when subjected to a magnetic field, the current being indicative of a position of the corresponding coil; and A plurality of electrodes are connected to the distal tip along the longitudinal axis, each electrode being configured to: (i) sense anatomical signals in the vein of Marshall and provide electrical signals indicative of the anatomical signals, or (ii) transmit ablation energy to a target tissue region proximate the vein of Marshall. 2 . The medical probe of claim 1 , each electrode comprising a ring electrode including an electrode axis coaxial with the longitudinal axis. 3 . The medical probe of claim 1 , a first coil of the plurality of coils disposed within the distal tip and positioned so as to overlap a distal-most electrode of the plurality of electrodes along the longitudinal axis.

4. The medical probe of claim 3, wherein the plurality of coils further comprises a second coil and a third coil, wherein the second coil and the third coil are positioned away from the distal end of the distal tip such that the second coil and the third coil do not overlap with each of the plurality of electrodes.

5. The medical probe according to claim 1, wherein the elongated shaft comprises: outer wall; and A lumen wall defines the lumen. 6 . The medical probe according to claim 5 , each coil being arranged between the outer wall and the lumen wall.

7. The medical probe of claim 1, the outer diameter of the elongated shaft being between approximately 0.04 inches and 0.05 inches.

8. The medical probe of claim 1, each coil comprising a single-axis sensor selected from the group consisting of a flat spiral coil, a cylindrical coil, or a combination thereof.

9. The medical probe of claim 1, each electrode being configured to: (i) sense the anatomical signal in the vein of Marshall and provide the electrical signal indicative of the anatomical signal, and (ii) transmit the ablation energy to the target tissue region proximate the vein of Marshall.

10. A system, comprising: A medical probe, comprising: an elongated shaft extending along a longitudinal axis and sized to be inserted into the vein of Marshall, the elongated shaft including a distal tip and defining a lumen therethrough; a guidewire extending through the lumen; a plurality of coils coupled to the distal tip along the longitudinal axis, each coil configured to generate a current when subjected to a magnetic field, the current being indicative of a position of the corresponding coil; and a plurality of electrodes coupled to the distal tip along the longitudinal axis, each electrode configured to: (i) sense anatomical signals in the vein of Marshall and provide electrical signals indicative of the anatomical signals, or (ii) deliver ablation energy to a target tissue region proximate the vein of Marshall; and A processor is configured to estimate the position of the distal tip based on the generated current and (i) estimate at least one characteristic of the anatomical signal based on the electrical signal or (ii) provide a signal to transmit the ablation energy to the electrode.

11. The system of claim 10, each electrode comprising a ring electrode including an electrode axis coaxial with the longitudinal axis.

12. The system of claim 10, each coil disposed within the distal tip and positioned so as to overlap a corresponding electrode of the plurality of electrodes along the longitudinal axis.

13. The system of claim 12, wherein the elongated shaft comprises an outer wall and a lumen wall defining the lumen, each coil being disposed between the outer wall and the lumen wall.

14. The system of claim 10, each coil comprising a single axis sensor.

15. A system, comprising: an elongated probe extending along a longitudinal axis and sized to be inserted into the coronary sinus, the elongated catheter shaft including an opening; an over-the-wire catheter extending through the opening along the longitudinal axis and sized to be inserted into the vein of Marshall; a first plurality of electrodes connected to the elongated probe along the longitudinal axis; and a second plurality of electrodes connected to the guidewire catheter along the longitudinal axis, Each electrode of the first plurality of electrodes and the second plurality of electrodes is configured as: (i) generating an electrical current indicative of a position of a corresponding electrode, and (ii) sensing an anatomical signal of tissue and providing an electrical signal indicative of the anatomical signal.

16. The system of claim 15, each electrode further configured to deliver ablative energy to a target tissue region proximate the vein of Marshall.

17. The system of claim 15, further comprising an inflatable probe balloon connected to the elongated probe.

18. The system of claim 15, further comprising an inflatable guidewire balloon coupled to the guidewire catheter proximate the second plurality of electrodes.

19. The system of claim 15, wherein the guidewire catheter has an outer diameter of approximately 0.03 inches to 0.04 inches.

20. The system of claim 15, further comprising a guidewire, and the guidewire catheter defines a guidewire lumen therethrough, the guidewire extending through the guidewire lumen.

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