Medical probe for navigating small diameter blood vessels

Abstract

To provide a medical probe.SOLUTION: The disclosed technology includes medical probe that includes an elongated shaft, a guidewire, coils, and electrodes. The elongated shaft extends along a longitudinal axis and is dimensioned to be inserted into a vein of Marshall. The guidewire extends through a lumen in the elongated shaft. The coils are connected to the distal dip of the elongated shaft, and each coil is configured to generate a current when subjected to a magnetic field, the current being indicative of a position of the respective coil. The electrodes are connected to the distal tip. Each electrode is designed to (i) sense anatomical signals in the vein of Marshall and provide electrical signals which are indicative of the anatomical signals or (ii) convey ablation energy to a target tissue region proximal to the vein of Marshall.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This technology generally relates to medical devices, particularly medical probes having electrodes, and more particularly to medical probes suitable for use in the location tracking, anatomical sensing, and / or induction of irreversible electroporation (IRE) of cardiac tissue, but is not limited thereto.

Background Art

[0002] The Marshall ligament (LOM) located epicardially between the left atrial appendage and the left pulmonary vein is often the source of paroxysmal atrial fibrillation. 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. Some specific procedures that exist to treat arrhythmias include surgically destroying the source of the signals causing the arrhythmia and destroying the conduction pathways of such signals. By applying energy via a catheter to selectively ablate cardiac tissue, 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 the tissue, causing irreversible permeabilization of the cell membrane. Delivery of IRE energy to tissue using a multi-electrode probe 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.

[0006] Many regions of the heart are relatively easily accessible from the endocardium and are thus suitable for ablation with conventional catheters such as focal catheters or balloon catheters. However, typically, there are one or more relatively acute bends in the intracardiac pathway that the conventional catheter cannot cross, making access from the endocardium difficult, and there are specific regions of the heart, such as LOM, where access is difficult. These regions can sometimes be accessed from the epicardium, but access from the endocardium is preferred. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEM

[0007] According to the disclosed technology, a medical probe is provided that includes an elongated shaft, a guide wire, a plurality of coils, and a plurality of electrodes. The elongated shaft extends along a longitudinal axis and is sized to be inserted into the Marshall vein. The elongated shaft has a distal tip and defines a lumen. The guide wire extends through the lumen. The coils are connected to the distal tip along the longitudinal axis, and each coil is configured to generate an electric current when subjected to a magnetic field. The electric current indicates the position of each coil. The electrodes are connected to the distal tip along the longitudinal axis, and each electrode is configured to (i) sense an anatomical signal within the Marshall vein and provide an electrical signal indicative of the anatomical signal or (ii) transmit ablation energy to a target tissue region proximal to the Marshall vein.

[0008] According to the disclosed technology, a method of navigating a medical probe to the Marshall vein is further provided. The method includes inserting a guide wire through the coronary sinus into the Marshall vein. The method includes sliding an elongated shaft that extends along the longitudinal axis over the guide wire through the coronary sinus into the Marshall vein, the elongated shaft having a distal tip, and the plurality of coils and the plurality of electrodes being connected to the distal tip. The method includes generating respective electric currents in each of the plurality of coils by subjecting each coil to a magnetic field, the electric current indicating the position of each coil. The method includes positioning the distal tip within the Marshall vein. The method includes sensing an anatomical signal within the Marshall vein using at least one of the plurality of electrodes. The method includes providing an electrical signal indicative of the anatomical signal from the at least one electrode.

[0009] According to the disclosed technology, a system including a medical probe and a processor is further provided. The medical probe includes an elongated shaft, a guide wire, a plurality of coils, and a plurality of electrodes. The elongated shaft extends along a longitudinal axis and is sized to be inserted into the Marshall vein. The elongated shaft has a distal tip and defines a lumen therethrough. The guide wire extends through the lumen. The plurality of coils are connected to the distal tip along the longitudinal axis, and each coil is configured to generate an electric current when receiving a magnetic field, and the electric current indicates the position of each coil. The electrodes are connected to the distal tip along the longitudinal axis, and each electrode is configured to (i) sense an anatomical signal within the Marshall vein and provide an electrical signal indicative of the anatomical signal, or (ii) transmit ablation energy to a target tissue region proximal to the Marshall vein. The processor is configured to estimate the position of the distal tip based on the generated electric current and (i) estimate at least one characteristic of the anatomical signal based on the electrical signal, or (ii) provide a signal for transmitting ablation energy to the electrodes.

[0010] According to the disclosed technology, a system including an elongated probe and a guide wire catheter is further provided. The elongated probe extends along a longitudinal axis and is sized to be inserted into the coronary sinus. The elongated 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 elongated 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 an electric current indicative of the position of each electrode and (ii) sense an anatomical signal of the 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 further provided. This method includes inserting an elongated probe extending along a longitudinal axis into the coronary sinus, the elongated probe defining an opening and comprising a first plurality of electrodes. This method includes sliding a guide wire catheter comprising a second plurality of electrodes through the elongated probe, out of the opening of the elongated probe, and into the Marshall vein. This method includes generating respective currents at each of the first plurality of electrodes and the second plurality of electrodes, each current indicating the position of each respective electrode. This method includes sensing an anatomical signal within the Marshall vein using at least one of the second plurality of electrodes. This method includes providing an electrical signal indicative of the anatomical signal from at least one of the second plurality of electrodes.

Brief Description of the Drawings

[0012]

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DETAILED DESCRIPTION OF THE INVENTION

[0013] 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, show selected examples, 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 technique. This description enables those skilled in the art to make and use the disclosed technique and describes some embodiments, adaptations, variations, alternatives, and uses of the disclosed technique, including what is currently considered to be the best mode for practicing the disclosed technique.

[0014] As used herein, the term "about" or "substantially" with respect to any numerical value or range indicates a suitable dimensional tolerance that allows a component or collection thereof 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%. In addition, 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 position closer to the operator or physician, while "distal" indicates the position farther from the operator or physician.

[0015] As contemplated herein, the vasculature of "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 those of a human. It should be understood that the subject can be, for example, any applicable human patient.

[0016] As contemplated 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.

[0017] 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). 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 arrhythmia, 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 bodily tissue ablation, as would be understood by one of ordinary skill in the art.

[0018] As discussed herein, the terms "bipolar" and "unipolar", when used to refer to ablation schemes, describe different ablation schemes with respect to current path and electric field distribution. "Bipolar" refers to an ablation scheme that utilizes the current path between two electrodes, both of which are placed 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.

[0019] 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 precisely 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.

[0020] The present disclosure relates to a system, method or use and apparatus for position tracking and mapping within the coronary sinus and / or the vein of Marshall (VOM) for treating cardiac arrhythmias and for IRE ablation of cardiac tissue. Ablation energy is typically delivered to cardiac tissue (e.g., LOM) 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 without using fluoroscopy.

[0021] To improve a failing heart, ablation of heart tissue applying thermal techniques such as radio frequency (RF) energy and cryoablation is a well-known procedure. Typically, to successfully ablate using thermal techniques, it is necessary to measure the electrocardiogram potential at various locations in the myocardium. In addition, temperature measurements during ablation provide data that enables assessment of the effectiveness of the 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.

[0022] 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 heat-sensitive 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.

[0023] Electroporation can be induced by applying a pulsed electric field to biological cells to cause the reversible (temporary) or irreversible (permanent) generation 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 about 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.

[0024] The techniques of the present disclosure include systems and methods for applying an electrical signal from a catheter electrode disposed 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 for ablating target tissue by inducing irreversible electroporation. In some examples, the present systems and methods can be effective for inducing 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 hereby incorporated by reference in its entirety.

[0025] The effectiveness of a pulsed electric field, as well as 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. 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 given the same physical parameters. Examples of various systems and methods of ablation including 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.

[0026] Refer to FIG. 1, which shows an exemplary catheter-based electrophysiological mapping and ablation system 10. System 10 includes a plurality of catheters that are percutaneously inserted by physician 24 into the chambers or vascular structures of heart 12 through the vasculature of patient 23. Typically, probe 14 is used to sense or ablate elements of the heart that are difficult to access, and as an example, the sensing of anatomical signals and / or ablation of a portion of the LOM of heart 12 are described herein. However, it should be understood that medical probe 22 can also be used for other therapeutic and / or diagnostic purposes in the heart or other body organs with the necessary modifications. The plurality of catheters can include catheters dedicated to sensing intracardiac electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. An exemplary medical probe configured to sense IEGM, such as catheter 14, is shown herein. Physician 24 contacts the distal tip of catheter 14 with the heart wall to sense the target site of heart 12. For ablation, physician 24 similarly positions the distal end of the ablation catheter at the target site for ablation.

[0027] Catheter 14 is an exemplary catheter that includes one electrode, preferably a plurality of electrodes 26, optionally distributed on the probe body and configured to sense IEGM signals. Catheter 14 can additionally include one or more position sensors embedded at 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 (described in more detail below).

[0028] Magnetic-based position sensors can operate with a position 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 position 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.

[0029] The system 10 includes one or more electrode patches 38 disposed for skin contact on the patient 23 to establish position referencing of the position pad 25 and impedance-based tracking of the electrodes 26. For impedance-based tracking, current is directed to the electrodes 26 and sensed at the electrode skin patches 38, whereby 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.

[0030] The recorder 11 displays an electrogram 21 captured by the body surface ECG electrodes 18 and an intracardiac electrogram (IEGM) captured by the electrodes 26 of the catheter 14. The recorder 11 may include pacing capabilities for pacing the rhythm of the heart and / or may be electrically connected to an independent pacer.

[0031] 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, pulsed field ablation (PFA) energy, or a combination thereof, including unipolar or bipolar high voltage DC pulses such as may be used to effect irreversible electroporation (IRE), but is not limited thereto.

[0032] Patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheter, the electrophysiology equipment, the power supply, and a workstation 55 that controls the operation of system 10. The electrophysiology equipment of system 10 may include, for example, a plurality of catheters, position pads 25, body surface ECG electrodes 18, electrode patches 38, ablation energy generator 50, and recorder 11. Optionally, and preferably, PIU 30 additionally includes processing capabilities for implementing real-time calculation of the position of the catheter and performing ECG calculations.

[0033] The workstation 55 includes a memory, a processor unit having a memory or storage device loaded with appropriate operating software, and a user interface function. The workstation 55 optionally provides a plurality of functions including: (1) modeling the endocardial anatomical structure in three dimensions (3D) and rendering it to display a model or anatomical map 20 on the display device 27; (2) displaying 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) displaying the real-time positions and orientations of a plurality of catheters within the heart chamber; and (5) displaying on the display device 27 a site of interest such as a location where ablation energy has been 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.

[0034] FIG. 2 is a schematic drawing 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 from the handle 1000 along a longitudinal axis 60 and includes a distal tip 28. The probe body 100 in the presently described example includes an elongate flexible shaft 102. The shaft 102 can be made of a flexible biocompatible electrical insulating material such as polyamide-polyether (Pebax) copolymer, polyethylene terephthalate (PET), urethane, polyimide, parylene, silicone. In some examples, the insulating material can include biocompatible polymers 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, although the ratio of specific polymers is selected to control the degree of the inflammatory response.

[0035] In the examples described herein, the electrode 26 can be used to determine the position of the probe body 100 and / or measure physiological / anatomical properties such as local surface potentials at respective positions on tissue within the heart 12. In addition to using the electrode 26 to determine position and / or measure anatomical signals, the electrode 26 can also be configured to deliver ablation energy (IRE and / or RF) to the tissue of the heart 12. In some examples, a set of the electrodes 26 can include a dome electrode 26A at the distal end of the probe body 100. As a lead electrode 26 at the distal end of the probe body 100, the dome electrode 26A can assist the physician 24 in navigating the catheter 14. The collected signals can be used to help guide the catheter 14 generally and particularly when imaging is not performed by other means.

[0036] Examples of materials that are ideally suitable for forming the electrode 26 include gold, platinum, and palladium (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 inside the spine) and then to the blood pool within the heart 12.

[0037] Figure 3 is a schematic drawing showing a cross-sectional side view of the probe body 100. A plurality of coils 33 are embedded within the probe body 100 at predetermined positions along the longitudinal axis 60. Each coil 33 is configured to generate an electric current when subjected to a magnetic field. In some examples, each coil 33 can include a single-axis sensor (SAS). The coil 33 can include a cylindrically wound conductive material or a flat spiral coil formed in a planar flexible circuit. The coil 33 can include a conducting wire for conducting the current induced on each coil 33 to the patient interface unit 30. As will be appreciated, it is possible to detect the position by attaching a plurality of coils 33 to the distal tip 28 of the probe body 100. In this way, after the physician 24 can more accurately determine the position of the distal end of the probe body 100, the probe body 100 can be used to sense anatomical signals and / or apply ablation energy to tissue within, for example, the VOM 42.

[0038] Figure 4 is a schematic drawing showing the coronary sinus 40, VOM 42, LOM 44, and great cardiac vein 48 with the probe body 100 inserted into the VOM 42. In the following description, for example, it is assumed that the target region 46 of the LOM 154 is to be mapped / sensed and / or ablated. Note that for the sake of explanation, the coils 33 are shown as virtual lines in this figure.

[0039] In a first step, 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 through the coronary sinus 40 into the LOM 44 until the distal end of the probe body 100 is proximate to the target region 46. The distal end of the probe body 100 can be manipulated, for example, by one or more pull wires integrated with the probe body 100. Physician 24 typically receives assistance with navigation by the processor 55 using signals from the sensor 33 or the electrodes 26 and displays an icon representing the position of the distal tip 28 of the probe body 100 on the map 20. Additionally, physician 24 can use fluoroscopy to assist with navigation.

[0040] In the mapping step and / or the sensing step, the impedance and / or current between the electrodes 26 and the patch 38 can be used to confirm the position of the electrodes 26 relative to the target region 46 by the current tracking module of the PIU 30. Additionally, the position of the electrodes can be confirmed by fluoroscopy. Once it is determined that the electrodes 26 are appropriately positioned relative to the target region 46, the medical probe body 100 is manipulated to bring one or more of the electrodes 26 into contact with the heart tissue (e.g., the endocardium). The electrodes 26 generate a potential gradient signal, also referred to herein as an electrical signal, in response to the sensed potential. In some embodiments, the sensed electrical signal indicates the direction and propagation speed of the wavefronts caused by anatomical signals such as electrocardiogram (ECG) signals within the heart 12.

[0041] In the ablation step, the physician 24 operates the processor 55 and the ablation energy generator 50 to supply current to the electrode 26. If there are two or more electrodes 26, 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 the electrode patch 38 etc.) connected to the patient's body.

[0042] In some examples, since an (alternating current) current such as an RF sine wave is supplied to the electrode 26, RF ablation of the tissue is performed. Alternatively, a pulsed current (direct current) may be supplied to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When the pulsed current is supplied to perform PFA, the unipolar ablation energy may be supplied by a direct current flowing between the electrode 26 on the elongate shaft 202 and the electrode patch 38 or the back patch. Further, the bipolar ablation energy can be supplied by a direct current flowing between the electrodes 26 on the elongate shaft 202 itself and / or another catheter 14A (such as a focal catheter or a multi-electrode catheter) within the left atrium 12A (see FIG. 1).

[0043] Once the physician 24 has completed the mapping and / or ablation, the physician can withdraw the medical probe body 100 from the patient 23. The foregoing method describes the mapping and / or ablation of one target area. Of course, the implementation of the technology currently being described is not limited to the sensing and / or ablation of a single area, but rather may 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 the coronary sinus 40 than the target area 46, the electrode 26 can be moved to be proximate to the second area, and the electrode 26 can be pushed to contact the second area in preparation for sensing of anatomical signals and / or ablation of the second area.

[0044] FIG. 5 is a schematic drawing of a side view of another medical probe 14 designed in accordance with the techniques of the present disclosure. FIG. 6 is a schematic drawing of a detailed view of detail A of FIG. 5. FIG. 7 is a schematic drawing of a cross-sectional view of the distal tip of the medical probe 14 of FIG. 5, showing a portion thereof cut away. FIG. 8 is a schematic drawing of an outer portion of the distal tip of the medical probe 14 of FIG. 5. FIG. 9 is a schematic drawing of an inner portion of the distal tip of the medical probe 14 of FIG. 5.

[0045] Referring to FIGS. 5-9, the medical device 14 includes a probe body 200 that extends parallel or coaxial to the longitudinal axis 60 and includes a distal tip 28. The probe body 200 is connected to a handle 1000. The handle 1000 can also be connected to an energy connector housing 2000 through which energy, such as PFA, can be sent for ablation purposes. The probe body 200 in the example currently being described includes an elongate flexible shaft 202 that 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 about 3-4 Fr, e.g., 0.04-0.05 inches.

[0046] As can be seen particularly in FIG. 7, the elongated 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 to the handle 1000. The outer wall 206, the lumen wall 208, and the connecting shaft 210 can each be made of a flexible biocompatible electrical insulating material such as polyamide-polyether (Pebax) copolymer, polyethylene terephthalate (PET), urethane, polyimide, parylene, silicone, etc. In some examples, the insulating material can include biocompatible polymers 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, although the ratio of specific polymers is selected to control the degree of the inflammatory response.

[0047] As shown in FIGS. 5-7, the guide wire 220 extends through a luer hub 222 within the handle 1000, through the lumen 204, and out of the distal end 202A of the elongated 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 0.01-0.02 inches. Since the guide wire 220 must bend around one or more acute angles, it will be understood that intracardiac navigation to difficult-to-access sites such as LOM44 is complex. For example, to reach LOM44, the guide wire 220 may need to pass through the inferior vena cava, the right atrium, and the coronary sinus 40. The complex navigation is facilitated by the guide wire 220, which is made very thin but is configured to be flexible without twisting.

[0048] Similar to the previous embodiments, the elongated shaft 202 includes, at its distal tip, an electrode 26 connected thereto. Specifically, the electrode 26 can be designed as a ring electrode 26 that extends around the outer wall 208, is coaxial with the longitudinal axis 60, and is spaced along the longitudinal axis 60. The ring electrode 26 can have an outer diameter similar to that of the elongated shaft 202 (e.g., between 0.04 inches and 0.05 inches), such that the ring electrode 26 is either substantially in the same plane as the elongated shaft 202 or slightly raised from the elongated shaft 202. The most distal electrode 26A can be designed as either a ring electrode or a dome electrode. As the lead electrode 26 at the distal end of the elongated shaft, the most distal electrode 26A can assist the physician 24 in navigating the catheter 14. The collected signals can be used to help guide the catheter 14, generally and particularly when imaging is not performed in other ways. As described above, in the examples described herein, the electrode 26 is used to determine the position of the probe body 200 and / or measure physiological / anatomical properties such as local surface potentials at respective positions on the tissue within the heart 12. In addition to using the electrode 26 to determine position and / or measure anatomical signals, the electrode 26 can also be configured to deliver ablation energy (IRE and / or RF) to the tissue within the heart 12.

[0049] In some examples, about 8 - 10 electrodes 26 having a predetermined spacing relative to each other along the longitudinal axis 60 can be provided on the elongated shaft 202. Referring particularly to FIG. 8, the example currently being described includes 10 electrodes 26, each electrode 26 having a height H1 and a predetermined spacing length L1 - L10 relative to the distal end 202A of the elongated shaft 202. By way of example only, and not limiting the scope of the present disclosure, the electrodes 26 can have a height H1 of about 1 millimeter and a spacing of 2 millimeters from each other (e.g., L1, which is the position of the distal end of the most distal electrode 26, is substantially coplanar with the distal end 202A, i.e., 0 millimeters from the distal end). L2, which is the distal end of the second most distal electrode 26, is about 2 millimeters from there. L3, which is the distal end of the third most distal electrode 26, is about 4 millimeters from there, etc.). Also, the total length of the outer wall 206 is LT. In some examples, LT is about 130 millimeters.

[0050] In addition to the above, as shown in FIGS. 7 and 9, within the probe body 200, a plurality (e.g., three) of coils 33 are embedded at predetermined positions along the longitudinal axis 60. Each coil 33 can be configured to generate an electric current when subjected to a magnetic field. In some examples, each coil 33 can include a single - axis sensor (SAS). The coil 33 can include a conductive material wound around the coil or a coil formed in a flexible circuit. The coil 33 can include conductors for conducting the current induced on each coil 33 to the patient interface unit 30. As will be understood, by attaching the plurality of coils 33 to the distal tip 28 of the probe body 100, it is possible to detect its position. In this way, after the physician 24 can more accurately determine the position of the distal end of the probe body 100, the probe body 100 can be used to sense anatomical signals and / or apply ablation energy to tissue within, for example, the VOM 42.

[0051] Continuing to refer to FIGS. 7 and 9, each coil 33 is attached to the lumen wall 208 such that each coil 33 is disposed (i.e., sandwiched) between the outer wall 206 and the lumen wall 208. Similar to the electrodes 26, the distal ends of each coil 33 have predetermined positions (L11, L12, and L13, respectively) with respect to the distal end 202A of the elongate shaft 202. Specifically, for example, the distal end L11 of the most distal coil 33 is in substantially the same plane as (i.e., approximately 0 millimeters from) the distal end 202A of the elongate shaft 202, the distal end L12 of the intermediate 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, at the aforementioned exemplary predetermined positions, the most distal coil 33 overlaps the most distal electrode 26 along the longitudinal axis 60, while the intermediate and most proximal coils 33 are sufficiently spaced apart from the distal end 202A of the elongate shaft 202 such that they do not overlap any of the electrodes 26 and are both disposed more proximally along the longitudinal axis 60 than all of the electrodes 26.

[0052] Of course, other coil 33 configurations may also be suitable. For example, (instead of three) two coils 33 may be sufficient to track the position of the distal tip 28. As another example, instead of arranging the intermediate and most proximal coils 33 so that they do not overlap any of the electrodes 26 along the longitudinal axis 60, some or all of the coils 33 can be arranged to overlap the position of the electrodes 26 (similar to that shown in FIG. 4).

[0053] In addition, in some examples, the elongate shaft 202 can also include an inflatable balloon 230. As shown in FIG. 8 (in which the balloon 230 is not inflated in this figure), the balloon 230 is provided proximal to the handle 1000 relative to some or all of the electrodes 26 and is inflatable via a balloon lumen extending through the elongate shaft 202 for purposes that will be discussed in more detail below.

[0054] FIG. 10 is a schematic drawing showing the coronary sinus 40, VOM 42, LOM 44, and great cardiac vein 48, with the probe body 200 proximal to the VOM 42 and the guide wire 220 inserted into the VOM 42. FIG. 11A is a schematic drawing showing the probe body 200 inserted into the VOM 42. FIG. 11B is a schematic drawing showing the probe body 200 inserted further into the VOM 42 than the depiction of FIG. 11A. In the following description, by way of example, it is assumed that the target region 46 of the LOM 154 is to be mapped / sensed and / or ablated. Of course, it will be understood that the target region 46 may be of various sizes and configurations and not necessarily as shown in the figures. Note that for the sake of explanation, the lumen 204 and coil 33 are shown as phantom lines in these figures.

[0055] In a first step, the physician 24 inserts the probe body 200 and the guide wire 220 into the subject and then navigates the guide wire 220 into the heart 12. Within the heart 12, the probe body 200 and the guide wire 220 are navigated through the coronary sinus 40 until the distal end of the probe body 200 is proximal to the entrance of the VOM 42 (e.g., as shown in FIG. 10). The position of the entrance to the VOM 42 can be determined by the physician 24 using signals received from one or more of the coil 33 and / or electrode 26. In this way, the physician 24 receives assistance with navigation by the processor 55 using signals from the sensor 33 or electrode 26 and displays an icon representing the position of the distal tip 28 of the probe body 200 on the map 20. In addition, the physician 24 can use fluoroscopy to assist with navigation.

[0056] In the step of inserting the guide wire 220, once the position of the entrance to the VOM 42 is identified as shown in FIG. 10, the guide wire 220 is extended distally from the lumen 204 and sent into the VOM 42. The guide wire 220 reduces the complexity of entering the VOM 42, which is difficult to access as described above.

[0057] In the probe body 200 insertion step, as shown in FIG. 11A, when the guide wire 220 is sent into the VOM 42, the distal tip 28 of the elongated shaft 202 is slid into the VOM 42 along the guide wire 220 until it reaches its target region 46. Additionally, or alternatively, the elongated shaft 202 can be further inserted into the VOM 42, as shown in FIG. 11B.

[0058] In the balloon inflation step, as shown in FIGS. 11A and 11B, 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 shown in FIG. 11A, the balloon 230 occludes the coronary sinus 40. As shown in FIG. 11B, when the elongated shaft 202 is further inserted into the VOM 42, the balloon 230 is positioned such that it can be inflated to occlude the VOM 42. This aids in maintaining the probe body 200 in the desired position and also prevents the flow of fluid within the occluded blood vessel in scenarios where a foreign fluid (e.g., ethanol or saline) is injected into the blood vessel via the lumen 204, which will be discussed in more detail below. For that purpose (position retention and / or occlusion), its complex design is not required (e.g., since the electrodes are not being directly used for mapping and / or ablation, they are not placed on the balloon 230).

[0059] In the mapping step and / or the sensing step, the position of the electrode 26 relative to the target region 46 can be confirmed 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 confirmed by fluoroscopy. When it is determined that the electrode 26 is properly positioned relative to the target region 46 (e.g., by each coil receiving a magnetic field to generate its respective current, the current indicating the position of each coil 33), the medical probe body 200 is operated to bring one or more of the electrodes 26 into contact with the intracardiac tissue, such as the inner surface of the heart. The 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 the heart 12.

[0060] In the ablation step, the physician 24 operates the processor 55 and the ablation energy generator 50 to supply current to the electrode 26. If more than one electrode 26 is 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 (e.g., if only one electrode 26 is present), the supplied ablation energy may be monopolar, i.e., the current may be applied between one of the electrodes 26 and a return electrode (not shown) connected to the generator 50. The return electrode may be disposed outside the patient 23's body. For example, the return electrode may include a patch (e.g., the electrode patch 38, etc.) connected to the patient's body.

[0061] 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 (direct current) 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 a direct current flowing between electrode 26 on elongate shaft 202 and electrode patch 38 or the back patch. Further, bipolar ablation energy can be supplied by a direct current flowing between electrodes 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 FIG. 1).

[0062] In addition, or alternatively, in some examples, lumen 204 can be used to send ethanol through it to perform chemical ablation of LOM 44. In such an embodiment, balloon 230 proximal to electrode 26 is inflated to occlude VOM 42, as shown in FIG. 11B (as described above). FIGS. 11A and 11B show exemplary positions where balloon 230 can be manipulated to occlude different blood vessels of heart 12. Further, saline can also be sent through lumen 204 for use as a virtual electrode. The inflated balloon 230 prevents the injected fluid from flowing out before ablation can be performed.

[0063] Once physician 24 has completed mapping / sensing and / or ablation, the physician can withdraw the medical probe body 200 and the guide wire from patient 23. The foregoing method describes mapping / sensing and / or ablation of one target region. Of course, the implementation of the presently described technique is not limited to sensing and / or ablation of a single region, but rather may be used to map / sense and / or ablate two or more separate regions (or an entire blood vessel) 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 to be proximate to the second region, and the electrode 26 can be pushed to contact the second region in preparation for sensing of anatomical signals and / or ablation of the second region.

[0064] FIG. 12 is a schematic drawing of a side view of another medical probe 14 designed in accordance with the techniques of the present disclosure. FIG. 13 is a schematic drawing showing a heart 12 having a proximal elongated probe 310 (embodied as a shaft) of the VOM 42 and a guide wire catheter 302 inserted into the VOM 42.

[0065] Referring to FIG. 12, the medical device 14 includes a probe body 300 that extends parallel or coaxial to the longitudinal axis 60 and includes a distal tip 28. The probe body 200 is connected to a handle 1000 (not specifically shown in this example, but it is understood that it can take the form of the foregoing handle 1000). The handle 1000 can also be connected to an energy connector housing through which energy, such as PFA, can be sent for ablation purposes.

[0066] In the example being described, the probe body 300 includes an elongated coronary sinus catheter embodied as an elongated probe 310 that extends along (e.g., coaxially with) the longitudinal axis 60. The elongated probe 310 defines a primary lumen, a distal end opening (right side of FIG. 12), and a side opening 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 about 6-7 Fr, e.g., 0.08-0.09 inches.

[0067] The elongated probe 310 includes a plurality of electrodes 26 (e.g., ring electrodes that are substantially coplanar with the probe 310 or that 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 is inflatable via an inflation lumen that extends through the elongated probe 310, which will be discussed in more detail below.

[0068] As shown in FIG. 12, a guide wire catheter 302 sized to be inserted into the vein of the Marshall 42 extends along (e.g., coaxially with) the longitudinal axis 60 through the primary lumen of the elongated probe 310. In use, the guide wire catheter 302 can extend through the distal end opening (FIG. 12) of the elongated probe 310 or through the side opening 312 (FIG. 13). Compared to the aforementioned guide wire 220, this guide wire catheter 302 has a larger outer diameter. For example, the guide wire catheter 302 in this embodiment has an outer diameter of about 0.03-0.04 inches (2-3 Fr). Through the guide wire catheter 302, there is a guide wire lumen (embodied similarly to the aforementioned lumen 204), through which a guide wire 302A (e.g., having a diameter of about.010-.014 inches) passes, which assists the guide wire catheter 302 in intracardiac navigation and will be discussed in more detail below.

[0069] The guidewire catheter 302 includes a plurality of electrodes 26 (e.g., ring electrodes that are substantially coplanar with or slightly raised from the catheter 302) connected thereto along the longitudinal axis 60. The guidewire catheter 302 can also include the most distal electrode 26A as described above. The guidewire catheter 302 is also inflatable via a balloon lumen extending through the guidewire catheter 302 and can include a guidewire balloon 304 provided proximal to the handle 1000 relative to some or all of the electrodes 26, which will be discussed in more detail below.

[0070] The probe 310 and the guidewire catheter 302 can each be made of a flexible biocompatible electrical insulating material such as polyamide-polyether (Pebax) copolymer, polyethylene terephthalate (PET), urethane, polyimide, parylene, silicone, etc. In some examples, the insulating material can include biocompatible polymers 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, although the ratio of specific polymers is selected to control the degree of the inflammatory response.

[0071] Figure 13 shows an exemplary use of the probe body 300. In a first step, physician 24 inserts the elongated probe 310 and the guide wire catheter 302 (which is retracted within the coronary sinus catheter 310) into the subject and then navigates them into the heart 12. Within the heart 12, the coronary sinus catheter 310 and the guide wire catheter 302 are navigated through the coronary sinus 40 until the distal end of the coronary sinus catheter 310 is proximate to the entrance of the VOM 42. The position of the entrance to the VOM 42 can be determined by physician 24 using signals received from the electrodes 26 of the elongated probe 310 and / or the guide wire catheter 302. In this way, physician 24 receives assistance from the processor 55 in navigating using the signals from the electrodes 26 and displays an icon representing the position of the distal tip 28 of the probe body 300 on the map 20. Additionally, physician 24 can use fluoroscopy to assist in the navigation.

[0072] In the balloon inflation step, as shown in FIG. 13, the probe balloon 314 can optionally be inflated to occlude the coronary sinus 40 and / or the great cardiac vein 48, depending on the placement. This assists in maintaining the elongated probe 310 in the desired position and also prevents the flow of fluid within the occluded blood vessel in scenarios where a foreign fluid (e.g., ethanol or saline) is injected into the blood vessel through the guide wire catheter 302, which is discussed in more detail below. For that purpose (position retention and / or occlusion), a complex design is not required (e.g., since the electrodes are not being used directly for mapping and / or ablation, they are not placed on the probe balloon 314).

[0073] In the insertion step of the guide wire catheter 302, as shown in FIG. 13, once the position of the entrance to the VOM 42 is identified, depending on the orientation and / or position of the elongated probe 310, the guide wire 302A first extends distally from the distal end opening or the side opening 312 (in FIG. 13, the guide wire catheter 302 exits from the side opening 312), is sent into the VOM 42, and then the guide wire catheter 302 is slid over the guide wire 302A. In this way, the guide wire 302A assists in operating the guide wire catheter 302 out of one of the openings of the elongated probe 310 and into the VOM 42, which is difficult to access as described above. Once the VOM 42 is accessed, if necessary, the guide wire balloon 304 can be inflated to occlude the VOM 42 and / or maintain the guide wire catheter 302 in a predetermined position. For that purpose (position retention and / or occlusion), its complex design is not required (for example, since the electrodes are not directly used for mapping and / or ablation, they are not arranged on the balloon 304).

[0074] In the mapping step and / or sensing step, the position of the electrodes 26 on the guide wire catheter 302 relative to the target area can be confirmed 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 confirmed by fluoroscopy. Once it is determined that the electrodes 26 are appropriately positioned relative to the target area, the guide wire catheter 302 is manipulated so that one or more of the electrodes 26 contact the intracardiac tissue (e.g., the intracardiac surface). The 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 a wavefront caused by an anatomical signal such as an electrocardiogram (ECG) signal within the heart 12.

[0075] In the ablation step, the physician 24 operates the processor 55 and the ablation energy generator 50 to supply current to the electrodes 26 of the guide wire catheter 302. If there are two or more electrodes 26, 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., electrode patch 38, etc.) connected to the patient's body.

[0076] In some examples, a (alternating current) current such as an RF sine wave is supplied to the electrodes 26, so that RF ablation of the tissue is performed. Alternatively, a pulsed current (direct current) may be supplied to perform irreversible electroporation (IRE) or pulsed field ablation (PFA). When a pulsed current is supplied to perform PFA, the unipolar ablation energy can be supplied by a direct current flowing between the electrode 26 on the guide wire catheter 302 and the electrode patch 38 or the back patch. Further, the bipolar ablation energy can be supplied by a direct current flowing between the electrodes 26 on the electrode 26 on the guide wire catheter 302 itself and / or the elongated probe 26 and / or another catheter 14A (e.g., a focus catheter or a multi-electrode catheter) in the left atrium 12A (see FIG. 1).

[0077] In addition, or alternatively, in some examples, the narrow-diameter guide wire lumen of the guide wire catheter 302 can be used to send ethanol for performing chemical ablation of the LOM 44 therethrough. In such examples, the guide wire balloon 304 is inflated to occlude the VOM 42. Further, saline can also be sent through the guide wire lumen for use as a virtual electrode. The inflated balloon 304 prevents the injected fluid from flowing out before ablation can be performed.

[0078] When physician 24 has completed the mapping / sensing and / or ablation, the physician can withdraw the medical probe body 300 and the guide wire from patient 23. The foregoing method describes the mapping / sensing and / or ablation of one target area. Of course, the implementation of the technology currently described is not limited to sensing and / or ablation of a single area, but rather may be used to map / sense and / or ablate two or more separate areas (or an entire blood vessel) during a single ablation procedure. For example, if there is a second target area closer to the coronary sinus 40 than the target area 46, the electrode 26 can be moved to be proximate to the second area, and the electrode 26 can be pushed to contact the second area in preparation for sensing of anatomical signals and / or ablation of the second area.

[0079] FIG. 14A is a schematic drawing of a side view of a variant of the guide wire catheter 302 described in connection with FIGS. 12 and 13. FIG. 14B is a schematic drawing of a detailed view of detail B shown in FIG. 14A. The guide wire catheter 302 shown in these figures is the same as the foregoing except that the guide wire lumen is not defined therethrough, and the guide wire 302A can be replaced or further provided with a non-traumatic material 302B at the distal end of the guide wire catheter 302, with the non-traumatic material 302B functioning as the guide wire tip.

[0080] The technology of the present disclosure described herein can be further understood in accordance with the following clauses. Clause 1. An elongated shaft that extends along the longitudinal axis and is sized to be inserted into the Marshall vein, the elongated shaft having a distal tip and defining a lumen, an elongated shaft, a guide wire extending through the lumen, and a plurality of coils connected to the distal tip along the longitudinal axis, each coil being configured to generate an electric current when receiving a magnetic field, the electric current indicating the position of each coil, a plurality of coils, and a plurality of electrodes connected to the distal tip along the longitudinal axis, each electrode being configured to (i) sense an anatomical signal within the Marshall vein and provide an electrical signal indicative of the anatomical signal, or (ii) transmit ablation energy to a target tissue region proximal to the Marshall vein, a medical probe.

[0081] Clause 2. The medical probe according to Clause 1, wherein the elongated shaft is coaxial with the longitudinal axis.

[0082] Clause 3. The medical probe according to any one of Clauses 1 to 2, wherein each electrode comprises a ring electrode having an electrode axis coaxial with the longitudinal axis.

[0083] Clause 4. The medical probe according to any one of Clauses 1 to 2, wherein the plurality of electrodes further comprises a dome electrode connected to the distal end of the distal tip.

[0084] Clause 5. The medical probe according to any one of Clauses 1 to 2, wherein the plurality of electrodes includes 8 to 10 ring electrodes arranged at an increment of about 2 millimeters from each other along the longitudinal axis with respect to the distal end of the distal tip.

[0085] Clause 6. The medical probe according to any one of Clauses 1 to 5, wherein the first coil of the plurality of coils is disposed within the distal tip and is disposed to overlap the most distal electrode of the plurality of electrodes along the longitudinal axis.

[0086] Clause 7. 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 tip such that the second coil and the third coil do not overlap with each of the plurality of electrodes. The medical probe according to Clause 6.

[0087] Clause 8. The elongate shaft includes an outer wall and a lumen wall that defines a lumen. The medical probe according to any one of Clauses 1 to 7.

[0088] Clause 9. Each coil is disposed between the outer wall and the lumen wall. The medical probe according to Clause 8.

[0089] Clause 10. The elongate shaft has an outer diameter between about 0.04 inches and 0.05 inches. The medical probe according to any one of Clauses 1 to 9.

[0090] Clause 11. Each coil includes a uniaxial sensor selected from the group consisting of a flat spiral coil, a cylindrical coil, or a combination thereof. The medical probe according to any one of Clauses 1 - 10.

[0091] Clause 12. The guidewire has a diameter between about 0.01 and 0.02 inches. The medical probe according to any one of Clauses 1 to 11.

[0092] Clause 13. Each electrode is configured to (i) sense anatomical signals within the Marshall vein and provide an electrical signal indicative of the anatomical signals, and (ii) transmit ablation energy to a target tissue region proximal to the Marshall vein. The medical probe according to any one of Clauses 1 to 12.

[0093] Article 14. A method for navigating a medical probe into the Marshall vein, comprising inserting a guidewire through the coronary sinus into the Marshall vein, and sliding an elongated shaft extending along the longitudinal axis over the guidewire through the coronary sinus into the Marshall vein, the elongated shaft having a distal tip, and a plurality of coils and a plurality of electrodes being connected to the distal tip, generating respective electric currents in each of the plurality of coils by each coil receiving a magnetic field, the electric currents indicating the positions of the respective coils, placing the distal tip within the Marshall vein, sensing an anatomical signal within the Marshall vein using at least one of the plurality of electrodes, and providing an electrical signal indicative of the anatomical signal from at least one of the electrodes.

[0094] Article 15. The method according to Article 14, wherein the anatomical signal includes an electrocardiogram signal.

[0095] Article 16. The method according to any one of Articles 14 to 15, further comprising delivering ablation energy to a target tissue region proximal to the Marshall vein.

[0096] Article 17. The method according to Article 16, wherein the ablation energy includes monopolar ablation energy transmitted by sending a direct current between at least one of the plurality of electrodes and an electrode patch.

[0097] Article 18. The method according to Article 16, wherein the ablation energy includes bipolar ablation energy transmitted by sending a direct current in a manner selected from the group consisting of between at least one of the plurality of electrodes and another of the plurality of electrodes, between at least one of the plurality of electrodes and a catheter positioned within the atrium, and combinations thereof.

[0098] Clause 19. A system comprising: an elongated shaft having a distal tip, dimensioned to extend along a longitudinal axis and to be inserted into a Marshall vein, the elongated shaft defining a lumen therethrough; a guidewire extending through the lumen; a plurality of coils connected to the distal tip along the longitudinal axis, each coil configured to generate an electric current when subjected to a magnetic field, the electric current indicative of the position of each coil; a plurality of electrodes connected to the distal tip along the longitudinal axis, each electrode configured to (i) sense an anatomical signal within the Marshall vein and provide an electrical signal indicative of the anatomical signal, or (ii) transmit ablation energy to a target tissue region proximal to the Marshall vein; and a processor configured to estimate the position of the distal tip based on the generated electric current and to (i) estimate at least one characteristic of the anatomical signal based on the electrical signal, or (ii) provide a signal for transmitting ablation energy to the electrodes.

[0099] Clause 20. The system of Clause 19, wherein the elongated shaft is coaxial with the longitudinal axis.

[0100] Clause 21. The system according to any one of Clauses 19 - 20, wherein each electrode comprises a ring electrode having an electrode axis coaxial with the longitudinal axis.

[0101] Clause 22. The system according to any one of Clauses 19 - 21, further comprising a dome electrode connected to the distal end of the distal tip.

[0102] Clause 23. The system according to any one of Clauses 19 - 22, wherein each coil is disposed within the distal tip and positioned to overlap each of the plurality of electrodes along the longitudinal axis.

[0103] Clause 24. The system of Clause 23, wherein the elongated 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.

[0104] Clause 25. The elongated shaft has an outer diameter between approximately 0.04 inches and 0.05 inches, and the system according to any one of Clauses 19 to 24.

[0105] Clause 26. Each coil includes a uniaxial sensor, and the system according to any one of Clauses 19 to 25.

[0106] Clause 27. The elongated shaft has a diameter between approximately 0.01 and 0.02 inches, and the system according to any one of Clauses 19 to 26.

[0107] Clause 28. An elongated probe that extends along the longitudinal axis and is sized to be inserted into the coronary sinus, the elongated probe having an opening in the elongated catheter shaft, a guide wire catheter that extends through the opening along the longitudinal axis and is sized to be inserted into the Marshall vein, a first plurality of electrodes connected to the elongated 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 indicating the position of each electrode and (ii) sense an anatomical signal of the tissue and provide an electrical signal indicating the anatomical signal.

[0108] Clause 29. Each electrode is further configured to transmit ablation energy to a target tissue region proximal to the Marshall vein, and the system according to Clause 28.

[0109] Clause 30. The opening is at the distal end of the elongated probe, and the system according to any one of Clauses 28 to 29.

[0110] Clause 31. The opening is spaced apart from the distal end of the elongated probe, and the system according to any one of Clauses 28 to 29.

[0111] Clause 32. The system according to any one of Clauses 28 to 31, further comprising an inflatable probe balloon connected to the elongated probe.

[0112] The system according to any one of clauses 28 to 32, further comprising an inflatable guide wire balloon connected to the guide wire catheter proximal to the second plurality of electrodes.

[0113] The system according to any one of clauses 28 to 33, wherein the guide wire catheter has an outer diameter of about 0.03 - 0.04 inches.

[0114] The system according to any one of clauses 28 to 34, wherein the elongate shaft has an outer diameter of about 0.08 - 0.09 inches.

[0115] The system according to any one of clauses 28 to 35, further comprising a guide wire, wherein the guide wire catheter defines a guide wire lumen through which the guide wire extends.

[0116] The system according to any one of clauses 28 to 36, wherein the elongate probe and the guide wire are coaxial with the longitudinal axis.

[0117] A method of 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 aperture and comprising a first plurality of electrodes; sliding a guide wire catheter through the elongate probe and out of the aperture of the elongate probe and into the Marshall vein, the guide wire catheter comprising a second plurality of electrodes; generating respective electric currents at each of the first plurality of electrodes and the second plurality of electrodes, each electric 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.

[0118] The method according to clause 38, wherein the anatomical signal includes an electrocardiogram signal.

[0119] The method according to any one of clauses 38 to 39, further comprising transmitting ablation energy to a target tissue region proximal to the Marshall vein.

[0120] The method according to clause 40, wherein the ablation energy includes monopolar ablation energy transmitted by sending a direct current between at least one electrode of the second plurality of electrodes and the electrode patch.

[0121] The method according to clause 40, wherein the ablation energy includes bipolar ablation energy transmitted by sending a direct current in a manner selected from the group consisting of 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, between at least one electrode of the second plurality of electrodes and a catheter positioned within the atrium, and combinations thereof.

[0122] The above embodiments are cited as examples, and the disclosed technology is not limited to those specifically illustrated and described in the above specification. Rather, the scope of the disclosed technology includes both combinations and sub - combinations of the various features described above, as well as those variations and modifications that would occur to those skilled in the art upon reading the foregoing description and that are not disclosed in the prior art.

[0123] 〔Embodiment〕 (1) A medical probe, An elongated shaft extending along a longitudinal axis and dimensioned to be inserted into the Marshall vein, the elongated shaft having a distal tip and defining a lumen, A guide wire extending through the lumen, A plurality of coils connected to the distal tip along the longitudinal axis, each coil being configured to generate a current when subjected to a magnetic field, the current indicating the position of each respective coil, a plurality of coils, A plurality of electrodes connected to the distal tip along the longitudinal axis, each electrode being configured to (i) sense anatomical signals within the Marshall vein and provide an electrical signal indicative of the anatomical signals, or (ii) transmit ablation energy to a target tissue region proximal to the Marshall vein. A medical probe comprising a plurality of electrodes. (2) The medical probe according to embodiment 1, wherein each electrode comprises a ring electrode having an electrode axis coaxial with the longitudinal axis. (3) The medical probe according to embodiment 1, wherein a first coil of the plurality of coils is disposed within the distal tip and positioned to overlap a most distal electrode of the plurality of electrodes along the longitudinal axis. (4) The medical probe according to embodiment 3, wherein the plurality of coils further comprises 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 tip such that the second coil and the third coil do not overlap each electrode of the plurality of electrodes. (5) The elongated shaft an outer wall, and a lumen wall defining the lumen. The medical probe according to embodiment 1.

[0124] (6) The medical probe according to embodiment 5, wherein each coil is disposed between the outer wall and the lumen wall. (7) The medical probe according to embodiment 1, wherein the elongated shaft has an outer diameter between about 1.016 mm and 1.27 mm (about 0.04 inches and 0.05 inches). (8) The medical probe according to embodiment 1, wherein each coil comprises a uniaxial sensor selected from the group consisting of a flat spiral coil, a cylindrical coil, or a combination thereof. (9) The medical probe according to embodiment 1, wherein each electrode is configured to (i) sense the anatomical signals within the Marshall vein and provide the electrical signal indicative of the anatomical signals, and (ii) transmit the ablation energy to the target tissue region proximal to the Marshall vein. (10) A system comprising: A medical probe comprising: An elongated shaft extending along a longitudinal axis and sized to be inserted into the Marshall vein, the elongated shaft having a distal tip and defining a lumen therethrough; A guidewire extending through the lumen; A plurality of coils connected to the distal tip along the longitudinal axis, each coil configured to generate a current when subjected to a magnetic field, the current indicative of the position of each respective coil; A plurality of electrodes connected to the distal tip along the longitudinal axis, each electrode configured to (i) sense an anatomical signal within the Marshall vein and provide an electrical signal indicative of the anatomical signal or (ii) transmit ablation energy to a target tissue region proximal to the Marshall vein; and a medical probe; A processor 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 for transmitting the ablation energy to the electrodes; and a system.

[0125] (11) The system of embodiment 10, wherein each electrode comprises a ring electrode having an electrode axis coaxial with the longitudinal axis. (12) The system of embodiment 10, wherein each coil is disposed within the distal tip and positioned to overlap each respective one of the plurality of electrodes along the longitudinal axis. (13) The system of embodiment 12, wherein the elongated shaft comprises an outer wall and a lumen wall defining the lumen, and each coil is disposed between the outer wall and the lumen wall. (14) The system of embodiment 10, wherein each coil comprises a uniaxial sensor. (15) A system comprising: An elongated probe dimensioned to extend along a longitudinal axis and be inserted into the coronary sinus, the elongated probe having an opening in an elongated catheter shaft, A guide wire catheter dimensioned to extend along the longitudinal axis through the opening and be inserted into the Marshall vein, A first plurality of electrodes connected to the elongated probe along the longitudinal axis, A second plurality of electrodes connected to the guide wire catheter along the longitudinal axis, wherein 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 respective electrode and (ii) sense an anatomical signal of tissue and provide an electrical signal indicative of the anatomical signal, a system.

[0126] (16) The system according to embodiment 15, wherein each electrode is further configured to transmit ablation energy to a target tissue region proximal to the Marshall vein. (17) The system according to embodiment 15, further comprising an inflatable probe balloon connected to the elongated probe. (18) The system according to embodiment 15, further comprising an inflatable guide wire balloon connected to the guide wire catheter proximal to the second plurality of electrodes. (19) The system according to embodiment 15, wherein the guide wire catheter has an outer diameter of about 0.762 - 1.016 mm (about 0.03 - 0.04 inches). (20) The system according to embodiment 15, further comprising a guide wire, wherein the guide wire catheter defines a guide wire lumen through which the guide wire extends.

Claims

1. 1. A medical probe comprising: an elongate shaft extending along a longitudinal axis and dimensioned for insertion into a Marshall vein, the elongate shaft including a distal tip and defining a lumen; a guidewire extending through the lumen; a plurality of coils connected to the distal tip along the longitudinal axis, each coil configured to generate an electric current when subjected to a magnetic field, the electric current being indicative of a position of the respective coil; a plurality of electrodes connected to the distal tip along the longitudinal axis, each electrode configured to (i) sense an anatomical signal within the Marshall vein and provide an electrical signal indicative of the anatomical signal, or (ii) deliver ablation energy to a target tissue region proximal to the Marshall vein.

2. The medical probe of claim 1 , wherein each electrode comprises a ring electrode with an electrode axis coaxial with the longitudinal axis.

3. 2. The medical probe of claim 1, wherein a first coil of the plurality of coils is disposed within the distal tip and positioned to overlap a distal-most electrode of the plurality of electrodes along the longitudinal axis.

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

5. The elongated shaft The exterior wall and The medical probe of claim 1 , further comprising a lumen wall defining the lumen.

6. The medical probe of claim 5 , wherein each coil is disposed between the outer wall and the lumen wall.

7. The medical probe of claim 1 , wherein the elongate shaft has an outer diameter of between about 0.04 inches and 0.05 inches.

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

9. 2. The medical probe of claim 1, 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 proximal to the Marshall vein.

10. 1. A system comprising:

1. A medical probe comprising: an elongate shaft extending along a longitudinal axis and dimensioned to be inserted into Marshall's vein, the elongate shaft including a distal tip and defining a lumen therethrough; a guidewire extending through the lumen; a plurality of coils connected to the distal tip along the longitudinal axis, each coil configured to generate an electric current when subjected to a magnetic field, the electric current being indicative of a position of the respective coil; a medical probe including: a plurality of electrodes connected to the distal tip along the longitudinal axis, each electrode configured to either (i) sense an anatomical signal within the Marshall vein and provide an electrical signal indicative of the anatomical signal, or (ii) deliver ablation energy to a target tissue region proximal to the Marshall vein; and a processor configured to estimate a 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 deliver the ablation energy to the electrode.

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

12. The system of claim 10 , wherein each coil is disposed within the distal tip and positioned to overlap a respective one of the plurality of electrodes along the longitudinal axis.

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

14. The system of claim 10 , wherein each coil comprises a single-axis sensor.

15. 1. A system comprising: an elongate probe extending along a longitudinal axis and dimensioned for insertion into the coronary sinus, the elongate catheter shaft comprising an opening; a guidewire catheter extending through the opening along the longitudinal axis and dimensioned for insertion into Marshall's vein; a first plurality of electrodes connected to the elongate probe along the longitudinal axis; a second plurality of electrodes connected to the guidewire catheter along the longitudinal axis; A system, wherein each electrode of the first plurality of electrodes and the second plurality of electrodes is configured to (i) generate an electrical current indicative of a position of the respective electrode, and (ii) sense an anatomical signal of tissue and provide an electrical signal indicative of the anatomical signal.

16. 16. The system of claim 15, wherein each electrode is further configured to deliver ablation energy to a target tissue region proximal to the Marshall's vein.

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

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

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

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

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