Pulsed-field ablation catheter

Abstract

To provide a catheter.SOLUTION: The catheter can have a distal circular region that can contract in circumference via manipulation of a pull wire. The circular region can have electrodes distributed around the circumference that are suitable for mapping and / or ablation, and preferably suitable for IRE ablation. The catheter can include a cross-over region near a distal end of a shaft in which elongated elements extend at an angle to the longitudinal axis. The cross-over region can be bounded by an intermediate tube having four lumens and a distal tube having three lumens. The circular region can include structural features to facilitate contraction such as a support member having a preferable bending direction, polymer tubing segments positioned to inhibit bending stress on electrodes, navigation sensors positioned to inhibit bending stress on the sensors and electrodes, and a distal assembly at a distal end of the circular region.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a catheter that is particularly useful for performing pulse field ablation within or near the heart. The catheter may also be useful for mapping and / or thermal ablation using high frequency electrical signals.

Background Art

[0002] Cardiac arrhythmias, such as atrial fibrillation, occur when electrical signals abnormally conduct from a specific region of heart tissue to adjacent tissue, thereby disrupting the normal cardiac cycle and causing an asynchronous rhythm. The unwanted signal source is typically located in atrial or ventricular tissue. Regardless of the source, the unwanted signal can travel through the heart tissue to other locations, causing or continuing an arrhythmia.

[0003] Treatment of cardiac arrhythmias can involve disrupting the conduction pathway of the electrical signals causing the arrhythmia to stop or reduce the propagation of unwanted electrical signals from one part of the heart to another. Such procedures typically involve a two-step process: (1) mapping and (2) ablation. During mapping, a catheter having an end effector preferably with a high density of electrodes is moved across the target tissue, electrical signals are acquired from each electrode, and a map is generated based on the acquired signals. During ablation, non-conductive lesions are formed in regions selected based on the map to interrupt electrical signals passing through those regions. Currently, the most common ablation technique involves applying a high frequency (RF) electrical signal through an electrode to the tissue to generate heat. Irreversible electroporation (IRE) ablation is a more recently developed technique that involves applying short-duration high voltage pulses across the tissue to cause cell death.

[0004] The different purposes of mapping, RF signal ablation, and IRE ablation generally result in different catheter design goals. As a non-exclusive list, several catheters having circular, semicircular, or helical end-effectors for mapping and / or ablation are described in U.S. Patent Nos. 6,973,339, 7,371,232, 8,275,440, 8,475,450, 8,600,472, 8,608,735, 9,050,010, 9,788,893, 9,848,948, and U.S. Patent Publication 2017 / 0100188, each of which is incorporated herein by reference and attached to priority application U.S. Patent No. 63 / 220,312. [Overview of the project] [Means for solving the problem]

[0005] Generally, typical catheters presented herein have an elongated shaft defining the longitudinal axis of the catheter and a circular region at the distal end of the elongated shaft that is roughly transverse to the longitudinal axis. The circular region can be contracted in circumference (and therefore diameter) when the pull wire extending through the circular region and the shaft is operated by a control handle at the proximal end of the shaft. The circular region may have electrodes distributed around the circumference, suitable for mapping and / or ablation, preferably suitable for IRE ablation. Typical catheters may include several elongated elements (e.g., the pull wire, electrical wire, mechanical support structure, and / or irrigation tube, etc.) extending through a crossover region near the distal end of the shaft, some or all of which are angled with respect to the longitudinal axis. The crossover region may be bounded by an intermediate tube having four lumens and a distal tube having three lumens. One or more of the distal tube lumens may be non-coaxial with the intermediate tube lumens, and thus elongated elements extending between non-coaxial lumens are angled with respect to the longitudinal axis within the crossover region. A typical catheter may have features for providing structural supports, such as support members, with a preferred bending direction when a force is applied to contract the circular region; polymer tube sections positioned to suppress bending stress on the electrodes; positions of sensors and navigation sensors to suppress bending stress on the electrodes; and a distal assembly at the distal end of the circular region. The tubular body of the circular region may measure about 8 French. Some overall configurations of typical catheters may result in a greater ability of the circular region to contract compared to existing catheters of similar dimensions.

[0006] A first representative catheter includes an elongated shaft extending along its longitudinal axis, an intermediate section extending distally from the elongated shaft along its longitudinal axis, and a distal section extending distally from the intermediate section. The intermediate section may include an intermediate tube having a first set of lumens through it. The distal section may include a generally linear region extending distally from the intermediate section along its longitudinal axis, and a circular main region distal to the generally linear region and generally perpendicular to the longitudinal axis. The distal section may include a distal tube having a second set of lumens through it.

[0007] The first representative catheter may include a crossover region between the distal end of the intermediate tube and the proximal end of the distal tube. The first representative catheter may include a support member mounted within the intermediate section in a first lumen of a first plurality of lumens, the support member extending through the distal section in a second lumen of a second plurality of lumens that are non-coaxial with the first lumen, and extending through the crossover region at an angle to the longitudinal axis.

[0008] The first set of lumens, and thereby the intermediate tube, may have four or more lumens. The second set of lumens, and thereby the distal tube, may have three or more lumens. Preferably, the first set of lumens may include exactly four lumens, and the second set of lumens may include exactly three lumens.

[0009] The first representative catheter may further include a first pull wire extending through an intermediate section within a third lumen of a first group of lumens that are non-coaxial with the first lumen, the first pull wire extending through a crossover region at an angle to the longitudinal axis, extending through a second lumen, and being attached within the distal section in close proximity to the distal end of a circular main region. The circular main region may be configured to resize its diameter in response to manipulation of the first pull wire.

[0010] The first representative catheter may further include a second pull wire extending through a fourth lumen of a first plurality of lumens in the intermediate section and fixed within the fourth lumen. The fourth lumen may be non-coaxial with the first and third lumens. The intermediate section may be configured to deflect from the longitudinal axis in response to the manipulation of the second pull wire.

[0011] A first representative catheter may further include a navigation sensor assembly having a guide coil positioned within a circular main region and a first plurality of wires extending proximal to the guide coil. The first plurality of wires may extend through a crossover region such that the first plurality of wires are angled with respect to the longitudinal axis and through a first lumen, and may extend through a fifth lumen of a second plurality of lumens that are non-coaxial with the first lumen.

[0012] The first representative catheter may further include electrodes distributed around a circular main region and configured to provide electrical energy to ablate intracardiac tissue using irreversible electroporation.

[0013] The first representative catheter may further include a second plurality of wires extending proximal to the electrode through a sixth lumen of a second plurality of lumens, the second plurality of wires extending through a crossover region so as to be angled with respect to the longitudinal axis, and extending through a seventh lumen of the first plurality of lumens which is non-coaxial with the sixth lumen.

[0014] A first representative catheter may further include a navigation sensor assembly having guide coils positioned within a circular main region such that each guide coil is surrounded by one of the corresponding electrodes.

[0015] Each electrode may have an outer diameter of approximately 8 French lengths, a length of approximately 3 millimeters, and an effective surface area of ​​approximately 21 square millimeters. The electrodes may be separated by a rim-to-rim distance of approximately 4 millimeters. The electrodes may be configured to withstand 900 volts between adjacent electrodes and 1800 volts between every other electrode.

[0016] The first representative catheter may further include polymer tube sections, each having a length of approximately 7 millimeters, each positioned on a support member, and each centrally positioned below its respective electrode, thereby providing, with respect to at least a portion of the electrodes, a preferred bending position between the electrodes along a circular main region.

[0017] The first representative catheter may further include a distal high-current positioning sensor mounted on a generally linear region of the distal section and a proximal high-current positioning sensor mounted on the intermediate section.

[0018] The support member may be configured such that, within a circular main region, its flexibility in the radial direction perpendicular to the longitudinal axis is greater than its flexibility in the longitudinal direction. The support member may have a substantially rectangular cross-sectional shape near the distal end of the distal section. The support member may have a substantially semicircular cross-sectional shape within the intermediate section. The rectangular cross-sectional shape may have height and width such that the width is at least twice the height, with the width measured substantially parallel to the longitudinal axis and the height measured substantially perpendicular to the longitudinal axis.

[0019] A first representative catheter may include a non-traumatic polymer dome at the distal end of the distal section, and a knotted cord positioned within the distal section, containing an ultra-high molecular weight polymer, and securing the polymer dome to the distal section.

[0020] A first representative catheter may further include a tubular sleeve having a length of approximately 7 millimeters, which is close to the distal end of the distal section, surrounds the distal portion of the distal section, and suppresses bending of the distal portion.

[0021] A second typical catheter includes an elongated shaft extending along its longitudinal axis, a distal section of the elongated shaft, a support member extending through the distal section, and a pull wire extending through the distal section. The distal section may include a generally linear region extending distally from the elongated shaft along its longitudinal axis, and a circular main region distal to the generally linear region and generally perpendicular to the longitudinal axis. The support member may be configured to have greater flexibility in the radial direction perpendicular to the longitudinal axis compared to flexibility in the longitudinal axis direction. The pull wire may be attached close to the distal end of the distal section and may be operated to contract the support member radially, thereby contracting the circular main region of the distal section radially.

[0022] The support member may have a substantially rectangular cross-sectional shape near the distal end of the distal section and a substantially semicircular cross-sectional shape near the proximal end of the distal section. The rectangular cross-sectional shape may have height and width such that the width is at least twice the height, with the width measured substantially parallel to the longitudinal axis and the height measured substantially perpendicular to the longitudinal axis.

[0023] A second typical catheter may further include electrodes distributed around a circular main region and configured to provide electrical energy for ablation of intracardiac tissue using irreversible electroporation. Each electrode may have an outer diameter of about 8 Frenchs, a length of about 3 millimeters, and an effective surface area of ​​about 21 square millimeters. The electrodes may be separated by a rim-to-rim distance of about 4 millimeters.

[0024] A second representative catheter may further include polymer tube sections, each having a length of approximately 7 millimeters, each positioned on a support member and each centrally positioned below its respective electrode, thereby providing a preferred bending position between the electrodes along a circular main region.

[0025] The second exemplary catheter may further include a navigation sensor assembly that includes induction coils positioned within a circular main region such that each induction coil is surrounded by one of the electrodes, respectively.

[0026] The second exemplary catheter may further include a distal assembly at the distal end of the distal segment of the electrode. The distal assembly may include a distal region of the support member, a distal region of the pull wire, a steel ferrule joining the distal region of the pull wire to the distal region of the support member, a knotted cord including ultra-high molecular weight polymer, a distal region of a distal tube (in which the distal region of the support member, the distal region of the pull wire, the steel ferrule, and the knotted cord are disposed), a polymer reinforcement tube surrounding the distal region of the distal tube, and a non-traumatic polymer tip extending distally from the distal end of the distal tube and engaging the knotted cord.

[0027] The second exemplary catheter may further include an intermediate segment that is distal to the elongated shaft and proximal to the distal segment. The intermediate segment may include an intermediate tube having a first plurality of lumens therethrough. The support member and the pull wire may be disposed within separate lumens of the first plurality of lumens. The second exemplary catheter may further include a crossover segment that is distal to the intermediate segment and proximal to the distal segment. The distal segment may include a distal tube having a second plurality of lumens. The support member and the pull wire may be disposed together within a single lumen of the second plurality of lumens.

[0028] The second exemplary catheter may further include a navigation sensor assembly that includes an induction coil positioned within a circular main region and a wire extending proximally from the coil. The wire may be disposed within a separate lumen within the distal tube from the single lumen in which the support member and the pull wire are disposed. The wire may be disposed together within the intermediate tube within the lumen of the first plurality of lumens in which the support member is disposed.

[0029] A third exemplary catheter may include an elongated shaft extending along a longitudinal axis, an intermediate section extending along the longitudinal axis distal to the elongated shaft, a distal section distal to the intermediate section, an elongated structure extending through the distal section and the intermediate section, and a crossover region between the distal section and the intermediate section where at least one of the elongated structures is angled with respect to the longitudinal axis. The intermediate section may include an intermediate tube having four lumens therethrough. The distal section may include a generally linear region extending along the longitudinal axis distal to the intermediate section and a circular main region distal to the generally linear region and generally orthogonal to the longitudinal axis. The distal section may include a distal tube having three lumens therethrough. The elongated structure may extend through the three lumens of the distal tube and into at least some of the four lumens of the intermediate tube. The crossover region may be between the distal end of the intermediate tube and the proximal end of the distal tube.

[0030] The elongated structure may include a support structure that generally forms the circular main region in a circular shape, a pull wire attached to the support structure, an electrode wire, and a navigation sensor wire. The support structure, and thus the circular main region, may be configured to change size in diameter in response to manipulation of the pull wire. Any combination of the elongated structures extending through the crossover region may be angled with respect to the longitudinal axis.

[0031] The third exemplary catheter may further include electrodes disposed around the circular main region and configured to provide electrical energy to ablate intravascular tissue using irreversible electroporation.

Brief Description of the Drawings

[0032] The above and further aspects of the present invention are further discussed below with reference to the accompanying drawings, where similar figures in various drawings indicate similar structural elements and features. The drawings are not necessarily to scale and are primarily intended to illustrate the principles of the present invention. The figures show one or more implementations of the devices, systems, and methods of the present invention, not as limitations but merely as examples. [Figure 1] This is an illustration of the outline of a typical catheter according to an aspect of the present invention. [Figure 2A] This is an illustration of the contour diagrams of the intermediate section, crossover section, and distal section of a typical catheter according to an aspect of the present invention. [Figure 2B] This is an illustration of the distal end of the distal section of a typical catheter according to an aspect of the present invention. [Figure 2C] This is a diagram illustrating the distal end of the distal section according to an aspect of the present invention. [Figure 3A] This is an illustration of the contour diagram of the crossover portion and adjacent portion between the intermediate portion and the distal portion according to an aspect of the present invention. [Figure 3B] Figure 3A is an illustration of a cross-sectional view of the catheter portion shown in the diagram. [Figure 3C] Figure 3A is a cross-sectional view of the intermediate section. [Figure 3D] Figure 3A is a cross-sectional view of the distal section. [Figure 4] This is an equiangled cutaway view of the crossover portion and adjacent portion between the intermediate and distal sections according to an aspect of the present invention. [Figure 5A] This is an exploded view of an assembly including a support member, a pull wire, and a ferrule according to an aspect of the present invention. [Figure 5B] Figure 5A is a cross-sectional view of the support member. [Figure 5C] Figure 5A is a cross-sectional view of the support member. [Figure 5D] Figure 5A is a cross-sectional view of the support member. [Figure 6A] Figure 5A is an assembly diagram of the assembly shown. [Figure 6B]Figure 6A is a magnified view of the distal portion of the assembly shown. [Figure 7] This is a cross-sectional view of a linearly elongated distal section according to an aspect of the present invention. [Figure 8A] This is an illustration of a knotted cord for the distal end assembly of a catheter according to an aspect of the present invention. [Figure 8B] This is an enlarged view of the distal end of a catheter according to an aspect of the present invention. [Modes for carrying out the invention]

[0033] Documents incorporated herein by reference should be considered an integral part of this application, and unless any term is defined in such a way as to contradict the definition expressly or implicitly provided herein, only the definitions herein should be considered.

[0034] While representative embodiments of the disclosed technology are described in detail herein, it should be understood that other embodiments are contemplated. Therefore, the scope of the disclosed technology is not intended to be limited to the structural and arrangement details of the components described or shown in the drawings below. The disclosed technology is capable of other embodiments and can be implemented or performed in various ways. Features of the embodiments disclosed herein, including those disclosed in the appendices to priority application U.S. Patent No. 63 / 220,312, can be combined in a manner that is understandable to those skilled in the art, in accordance with the teachings herein.

[0035] Where used herein, the terms “about” or “approximately” for any number or range indicate a suitable dimensional tolerance that enables some or all of the components to function for the intended purposes described herein. More specifically, “about” or “approximately” may mean a range of values ​​within ±20% of the listed values, for example, “about 90%” may mean a range of values ​​between 71% and 99%.

[0036] As discussed herein, the terms “ablate” or “ablation” refer to the devices and corresponding systems of this disclosure and mean components and structural mechanisms configured to reduce or prevent the generation of irregular cardiac signals. Non-thermal ablations include the use of irreversible electroporation (IRE) to induce cell death, which are interchangeably referred to throughout this disclosure as pulsed electric field (PEF) and pulsed-field ablations (PFA). Thermal ablations include the use of extremely high temperatures to induce cell death and also include RF ablations. As for the devices and corresponding systems of this disclosure, “ablating” or “ablation” is used throughout this disclosure in relation to the ablation of cardiac tissue in specific conditions, including but not limited to arrhythmias, atrial flutter ablations, pulmonary vein isolation, supraventricular tachycardia ablations, and ventricular tachycardia ablations. The terms “ablate” or “ablation” refer to generally known methods, devices, and systems and include various forms of body tissue ablations as understood by those skilled in the art.

[0037] As discussed herein, the terms “bipolar” and “unipolar” describe different ablation schemes with respect to current paths and electric field distributions, when used to mean an ablation scheme. “Bipolar” means an ablation scheme that utilizes a current path between two electrodes positioned at the treatment site, where the current density and electric flux density are typically approximately equal in each of the two electrodes. “Unipolar” means an ablation scheme that utilizes a current path between two electrodes, where one electrode with a high current density and high electric flux density is positioned at the treatment site, and a second electrode with a relatively low current density and lower electric flux density is positioned at a distance from the treatment site.

[0038] As discussed herein, the terms “biphasic pulse” and “monophesied pulse” mean the respective electrical signals. A “biphasic pulse” means an electrical signal having a positive voltage phase pulse (referred to herein as “positive phase”) and a negative voltage phase pulse (referred to herein as “negative phase”). A “monophesied pulse” means an electrical signal having only a positive phase or only a negative phase. Preferably, a system providing a biphasic pulse is configured to prevent the application of direct current (DC) voltage to the patient. For example, the average voltage of a biphasic pulse may be zero volts relative to ground or other common reference voltage. Additionally or alternatively, the system may include capacitors or other protective components. Where the voltage amplitudes of biphasic and / or monophasic pulses are described herein, it is understood that the expressed voltage amplitude is the absolute value of the approximate peak amplitude of the respective positive voltage phase and / or negative voltage phase. Preferably, each phase of a biphasic and monophasic pulse has a square shape with an essentially constant voltage amplitude for most of the phase duration. The phases of a biphasic pulse are temporally separated by an interphase delay. The duration of the interphase delay is preferably less than or approximately equal to the duration of each phase of the biphasic pulse. More preferably, the duration of the interphase delay is approximately 25% of the duration of each phase of the biphasic pulse.

[0039] As discussed herein, the terms “tubular” and “tube” are to be interpreted broadly and are not limited to a right cylindrical structure, a structure with a strictly circular cross-section, or a structure with a uniform cross-section over its entire length. For example, a tubular structure is generally illustrated as a substantially right cylindrical structure. However, a tubular structure may have a tapered or curved outer surface without departing from the scope of this disclosure.

[0040] The examples in this disclosure show a representative catheter 10 having a circular end effector with electrodes which can then be used for tissue mapping and / or ablation, which may be particularly useful for the diagnosis and / or treatment of cardiac arrhythmias. The representative catheter 10 shown may be modified to include conforming features of other catheters well known to those skilled in the art, including conforming features of a catheter disclosed in the appendix to priority application U.S. 63 / 220,312. Similarly, catheters well known to those skilled in the art, including those described in the appendix to priority application U.S. 63 / 220,312, may be modified to include conforming features of the representative catheter 10. Furthermore, the representative catheter 10 and its variations may be used to perform conforming treatments well known to those skilled in the art, including conforming treatments described in the appendix to priority application U.S. 63 / 220,312.

[0041] Figure 1 is a contour diagram of a typical catheter 10. The catheter 10 includes a distal portion 15 having a circular region that roughly traverses the longitudinal axis LL defined by the elongated shaft 12 of the catheter 10. The catheter 10 includes an intermediate section 14 that extends distally from the elongated shaft 12 along the longitudinal axis LL. The intermediate section 14 can be deflected from the longitudinal axis LL in response to manipulation of the handle 16 at the proximal end of the catheter 10. As shown, the intermediate section 14 may be bent to about 180°.

[0042] In a typical treatment, a suitable guidance sheath is inserted into the patient with its distal end positioned at the desired treatment location. One example of a suitable guidance sheath for use with a typical catheter 10 is the Vizigo® Braiding Guiding Sheath, commercially available from Biosense Webster, Inc. (California, USA). The distal end of the sheath is guided into one of the atria. As the catheter 10 is advanced through the guidance sheath, the distal section 15 is straightened to pass through the sheath. Once the distal end of the catheter is positioned at the desired treatment location, the guidance sheath is pulled proximal, allowing the intermediate section 14 and distal section 15 to extend outside the sheath, and the distal section 15 returns to its circular shape. Next, the distal section is inserted into the pulmonary vein or other tubular region (such as the coronary sinus, superior vena cava, or inferior vena cava), thereby bringing the outer circumference of the generally circular main region 39 into contact with the inner circumference of the tubular region. Preferably at least about 50%, more preferably at least about 70%, and even more preferably at least about 80% of the periphery of the generally circular main region is in contact with the inner circumference of the tubular region.

[0043] Figure 2A is an illustration of the contour diagram of the distal portion of the catheter 10, including the distal portion of the intermediate section 14, the distal section 15, and the crossover tube 20 positioned between the intermediate section 14 and the distal section 15. The distal section 15 includes a generally linear region 38 distal to the intermediate section 14. The generally linear region 38 is aligned with the intermediate section 14 and thereby with the longitudinal axis LL when the intermediate section 14 is aligned with the catheter shaft 12. The distal section 15 includes an elbow region 37 between the generally linear region 38 and the generally circular main region 39 of the distal section 15. The circular region 39 is distal to the linear region 38 and is generally perpendicular to the longitudinal axis LL. The circular region 39 is preferably generally almost perpendicular to the catheter body 12. As shown in Figure 2A, the circular region 39 may form a flat circle or may be slightly spiral.

[0044] The circular region 39 includes electrodes 26 distributed around its circumference. The electrodes 26 may be configured for mapping and / or ablation. In a typical treatment in which electrodes 26 are used to map electrical activity, the circular arrangement of electrodes 26 allows for the measurement of electrical activity around tubular body structures so that ectopic pulsations between electrodes can be identified. The dimensions of the generally circular main region 39 allow for the measurement of electrical activity along the diameter of the pulmonary veins or the diameter of the heart or other tubular structures near the heart, if the circular main region has a diameter that roughly corresponds to the diameter of the pulmonary veins or coronary sinuses. In a typical treatment in which electrodes 26 are used to perform ablation, the circular arrangement of electrodes 26 facilitates the formation of circular or annular injuries, blocking electrical activity through the circumference of the tubular body structure, thereby electrically isolating the tubular structure from the tissue opposite the annular injury.

[0045] Mapping and / or ablation may be performed using the Carto® system manufactured by Biosense Webster, or other suitable systems as understood by those skilled in the art, including the adapted system described in the appendix to priority application U.S. 63 / 220,312. Catheter 10 may be used to perform mapping and / or ablation as part of an adapted treatment, including the adapted treatment method described in the appendix to priority application U.S. 63 / 220,312.

[0046] The linear regions 38 of the intermediate section 14 and the distal section 15 each include a proximal annular electrode 22 and a distal annular electrode 24 which can be used to determine the position and orientation of the linear regions 38 of the intermediate section 14 and the distal section 15. The annular electrodes 22, 24 can be tracked, for example, by using impedance measurements at the annular electrodes with an Advanced Catheter Location (ACL) system manufactured by Biosense Webster, as described in U.S. Patent No. 8,456,182 incorporated herein by reference and attached to priority application U.S. Patent No. 63 / 220,312.

[0047] The distal end of the distal section 15 is sealed and enclosed with a non-traumatic dome 51 made of polyurethane adhesive or the like. A polymer support tube 28 positioned distal to the electrode 26 provides structural support for the distal portion of the distal section 15 and prevents bending of the distal portion.

[0048] Figure 2B is an illustration of the distal end of the distal section 15 of a typical catheter 10. The generally circular main region 39 may be curved in a clockwise or counterclockwise direction. The circular region 39 may contract radially R. When not contracted, the circular region 39 may have an outer diameter D1 preferably in the range of about 25 mm to about 35 mm. When contracted, the circular region 39 may have an outer diameter D2 preferably in the range of about 15 mm to about 25 mm. The circular region 39 may have a pull wire extending through it, which can be operated by a control handle 16 to contract the circular region 39.

[0049] The catheter 10 is preferably configured to provide IRE ablation voltage pulses from electrodes 26A-J. IRE is primarily a non-thermal process, which causes only a slight increase in tissue temperature over a maximum of a few milliseconds. Therefore, IRE differs from RF (radio frequency) ablation, which raises tissue temperature by 20-70°C and destroys cells by heating. IRE can utilize monophasic or biphasic pulses. Biphasic pulses are preferred to avoid muscle contraction from DC voltage. IRE pulses, alone or in combination with RF ablation, are incorporated herein by reference and attached to priority application U.S. Patent Publication No. 2021 / 0169550, No. 2021 / 0169567, No. 2021 / 0169568, U.S. Patent Application No. 62 / 949,999 (Agent Reference Number BIO6206USPSP1), U.S. Patent Publication No. 2021 / 0161592, U.S. Patent Application No. 16 / 731,238 (Agent Reference Number BIO6208USNP1), U.S. Patent Publication No. 16 / 710,062 (Agent Reference Number BIO6209USNP1), and U.S. Patent Publication No. 63 / 220,312, which is incorporated herein by reference. U.S. Patent Application No. 16 / 989,445, published as U.S. Patent Publication No. 2021 / 0186604, claiming priority to U.S. Patent No. 62 / 949,999 and incorporated herein by reference, U.S. Patent Application No. 16 / 731,238, published as U.S. Patent Publication No. 2021 / 0196372 and incorporated herein by reference, and U.S. Patent Application No. 16 / 710,062, published as U.S. Patent Publication No. 2021 / 0177503 and incorporated herein by reference, may occur and be applied at various temperatures.

[0050] In one example of treatment, IRE ablation may be performed by applying voltage pulses in a triplet array. In the first triplet array, a biphasic pulse may be applied between a first pair of adjacent electrodes 26A, 26B; then, a biphasic pulse of similar amplitude may be applied between a second pair of adjacent electrodes 26B, 26C; then, a biphasic pulse with approximately twice the amplitude of the previous biphasic pulse may be applied between every other electrode 26A, 26C, starting from the first pair of adjacent electrodes. The triplet array may continue from the first triplet and a new adjacent electrode 26D to a second triplet including two adjacent electrodes 26B, 26C. The second triad may follow a pattern similar to the first triad, with a biphasic pulse between the first pair of adjacent electrodes 26B, 26C, then with a biphasic pulse of similar amplitude between the second pair of adjacent electrodes 26C, 26D, and then with a biphasic pulse of approximately twice the amplitude between every other electrode 26B, 26D. The triad arrangement may continue with a third triad having the next three electrodes 26C, 26D, 26F, a fourth triad having the next three electrodes 26D, 26E, 26F, a fifth triad having the next three electrodes 26E, 26F, 26G, a sixth triad having the next three electrodes 26F, 26G, 26H, a seventh triad having the next three electrodes 26G, 26H, 26I, and an eighth triad having the next three electrodes 26H, 26I, 26J. The triplet pattern may be repeated and started again in the first triplet. The catheter 10 is preferably configured to withstand biphasic pulses between adjacent electrodes having an amplitude of about 900 volts and biphasic pulses between every other electrode having an amplitude of about 1,800 volts.

[0051] Figure 2C illustrates the distal end of the circular region 39 of the distal portion 15 in a straight configuration. The electrode 26 preferably has an outer diameter OD1 of about 8 French. The electrode 26 preferably has a length W1 of about 3 millimeters (mm). Each electrode 26 preferably has a length of about 21 mm. 2It has an effective surface area. The electrode 26 is preferably separated by an edge-to-edge distance W2 of about 4 mm. The most distal electrode 26A may be positioned at a length W3 of about 10 mm from the distal end of the tubular body of the circular region 39. The polymer support tube 28 preferably has a length W4 of about 7 mm.

[0052] Figure 3A illustrates the outline of the crossover tube 20 and adjacent parts of the intermediate section 14 and distal section 15.

[0053] Figure 3B is a cross-sectional view of the catheter portion shown in Figure 3A, cut by a plane containing the longitudinal axis LL. The cross-sectional view in Figure 3BC is shown in Figure 3A, cut by a plane perpendicular to the page and viewed upward toward the top of Figure 3A.

[0054] Figure 3C is a cross-sectional view of the intermediate section 14 perpendicular to the longitudinal axis LL shown in Figure 3A, and is located in a plane perpendicular to the page and viewed distally, towards the right side of Figure 3A.

[0055] Figure 3D is a cross-sectional view of distal section 15 as shown in Figure 3A, and is located in a plane perpendicular to the page and viewed distally, towards the right side of Figure 3A.

[0056] Referring together to Figures 3A to 3D, the intermediate section 14 includes an inner intermediate tube 17 having four lumens 41, 43, 44, and 47 passing through it, and the distal section 15 includes a distal tube 52 having three lumens 42, 45, and 46 passing through it. The intermediate tube 17 and the distal tube 52 may be modified to include an alternative number of lumens, as will be understood by those skilled in the art, in accordance with the teachings of this specification. The crossover region 21 extends between the distal end 34 of the intermediate tube 17 and the proximal end 32 of the distal tube 52 (see Figure 3B). The crossover region 21 is surrounded by a crossover tube 20, which has a single lumen.

[0057] A typical catheter 10 may include several elongated elements extending through the crossover region 21. The lumens 42, 45, and 46 of the distal tube 52 are non-coaxial with the lumens 41, 43, 44, and 47 of the intermediate tube 17. As a result, the elongated elements extending between the non-coaxial lumens are angled with respect to the longitudinal axis LL within the crossover region 21. Furthermore, the lumens 42, 45, and 46 of the distal tube 52 are non-coaxial with each other, and the lumens 41, 43, 44, and 47 of the intermediate tube 17 are non-coaxial with each other.

[0058] The catheter 10 includes a support member 54 having a proximal end mounted in a first lumen 41, extending distally with respect to the longitudinal axis LL through a crossover region 21 and distally into a second lumen 42, the first lumen 41 being in the intermediate tube 17 and the second lumen 42 being in the distal tube 52. The first lumen 41 and the second lumen 42 are non-coaxial with respect to each other, resulting in an angled trajectory of the support member 54 through the crossover region 21.

[0059] The catheter 10 includes a first pull wire / shrink wire 35 that extends from the handle 16, through the shaft 12, through a third lumen 43 in the intermediate tube 17, through a crossover region 21 at an angle to the longitudinal axis LL, and through the second lumen 42 of the distal tube 52. The third lumen 43 is non-coaxial with the second lumen 42, which angles the shrink wire 35 within the crossover region 21. The shrink wire 35 is attached within the distal section 15 near the distal end of the circular region 39. Manipulation of the handle 16 can create tension in the shrink wire 35 to shrink the circular region 39 to its diameter, as shown in Figure 2B. Within the second lumen 42, the catheter 10 may include a support member 54 and a braid 55 surrounding the shrink wire 35 to prevent the shrink wire 35 from being torn through the distal tube 52 (see Figure 3D). Within the third lumen, the catheter 10 may include a compression coil 61 surrounding the compression wire 35 (see Figure 3C).

[0060] The catheter 10 includes a second pull wire / deflection wire 36 extending from the control handle 16 through the shaft and through at least a portion of the fourth lumen 44 of the intermediate tube 17 (see Figure 3C). The distal end of the deflection wire 36 is fixed within the fourth lumen 44. The fourth lumen 44 is non-coaxial with the lumens 42, 45, and 46 of the distal tube 52. The intermediate section 14 is configured to deflect from the longitudinal axis LL in response to the manipulation of the deflection wire 36 by the control handle 16. Within the fourth lumen 44, the catheter 10 may include a compression coil 62 surrounding the deflection wire 36.

[0061] The compression coils 61, 62 may be made of any suitable metal, such as stainless steel. The compression coils 61, 62 may be tightly wound to provide flexibility, i.e., bendability, but resist compression. The inner diameter of the compression coils 61, 62 is preferably slightly larger than the diameter of the associated pull wires 35, 36. For example, if the pull wires 35, 36 have a diameter of about 0.007 inches (about 0.18 mm), each compression coil 61, 62 preferably has an inner diameter of about 0.008 inches (about 0.20 mm). By coating each pull wire 35, 36 with Teflon®, they can slide freely within the compression coils 61, 62. The outer surfaces of the compression coils 61, 62 may be covered with a flexible, non-conductive sheath to prevent contact between the compression coils and other components such as lead wires and cables. Each non-conductive tubular member may be made from polyimide tubing.

[0062] The catheter 10 may include a navigation sensor assembly 60 having guide coils 64, 65, and 66 in a circular region 39 (see Figure 7). The navigation sensor assembly 60 may include a conductor (e.g., wire, cable, printed trace, etc.) extending from an electrical connector on the handle 16 (not shown) through the shaft 12, through the first lumen 41 of the intermediate tube 17, through the crossover region 21 at an angle with respect to the longitudinal axis LL, and through the fifth lumen 45 in the distal tube 52. The fifth lumen 45 is non-coaxial with the first lumen 41, which causes the conductor of the navigation sensor assembly 60 to extend through the crossover region 21 at an angle with respect to the longitudinal axis LL. Details of the cross-section of the navigation sensor assembly 60 are omitted for the sake of simplicity in the figure.

[0063] The catheter 10 may include lead wires 40 that extend proximal to the electrode 26 in the circular region 39, pass through a sixth lumen 46 of the distal tube 52, through a crossover region 21 at an angle with respect to the longitudinal axis LL, through a seventh lumen 47 through the intermediate tube 17, through the shaft 12, through a control handle 16, and terminate at their proximal ends in a connector (not shown), connected to a suitable system configured to receive electrical signals to map and / or transmit energy for ablation. The lead wires 40 can be attached to the electrode 26 in the circular region 39 by any suitable prior art. The sixth lumen 46 is non-coaxial with the seventh lumen 47, thereby the lead wires 40 are angled with respect to the longitudinal axis LL through the crossover region 21. The lead wires 40 may be individually insulated and bundled within an insulating sleeve 48.

[0064] The catheter 10 may include a lead wire 72 connected to a proximal annular electrode 22 over an intermediate section 14 (Figure 3C). The catheter 10 may also include a lead wire 74 connected to a distal annular electrode 24 over a distal section 15 (Figure 3D).

[0065] The catheter 10 may include an outer tube 19 that surrounds the intermediate tube 17 and is configured to provide structural stability to the intermediate section 14. The outer tube 19 may extend proximal to the shaft 12, providing a continuous outer surface from the shaft 12 to the intermediate section 14.

[0066] Figure 4 is an isometric view of the crossover region 21 and adjacent portions of the intermediate section 14 and distal section 15. For illustrative purposes, the crossover tube 20 is omitted, and the outer tube 19, intermediate tube 17, and distal tube 52 are depicted as transparent. Fixing bars 75, 76 for the pull wires 35, 36 are shown in the intermediate tube 17.

[0067] Figure 5A is an exploded view of the assembly including the support member 54, the shrink wire 35, and the steel ferrule 77.

[0068] Figures 5B to 5D are cross-sectional views of the support member 54 shown in Figure 5A. As shown in Figure 5B, the support member 54 has a substantially semicircular cross-sectional shape near its proximal end. The support member 54 may have a substantially semicircular shape within the intermediate section 14. The semicircular shape has a width W5B that is substantially equal to or slightly greater than its height H5B. As shown in Figures 5C and 5D, the support member 54 gradually flattens towards its distal end, and the widths W5C and W5D increase as the heights H5C and H5D decrease. Near the distal end of the support member 54, the width W5D may be at least twice the height H5D.

[0069] The support member 54 is oriented in the circular region 39 such that its width is substantially aligned with the longitudinal axis LL and its height is aligned with the radial direction R (see Figure 2B). When oriented in this manner, the support member 54 is configured to bend preferentially in the radial direction R and resist bending in the direction of the longitudinal axis LL. Therefore, the support member 54 is more flexible in the radial direction R than in the longitudinal axis LL.

[0070] Figure 6A is an assembly diagram of the assembly shown in Figure 5A. The shrink wire 35 is attached to the distal end of the support member 54 by a ferrule 77, preferably made of steel or other suitable material. As shown, the shrink wire 35 is positioned on the radially inward-facing surface of the support member 54. When pulled, the shrink wire 35 shrinks, causing the support member 54 and, by extension, the circular region 39 to shrink radially. The braid 55 (see Figure 3D) bundles the shrink wire 35 and the support member 54 together, assisting the shrink wire 35 in shrinking the support member 54.

[0071] Figure 6B is a magnified view of the distal portion of the assembly shown in Figure 6A. The ferrule 77 preferably has a length W6 of about 2 mm to about 3 mm.

[0072] Figure 7 is a cross-sectional view of the distal section 15 of the catheter 10, which is extended in a linear shape. For illustrative purposes, the drawing omits certain features, such as the wire 40 to the electrode 26, the conductor to the navigation sensor assembly 60, the shrinkable wire 35, the omitted braid 55 around the support member 54, and the distal tube 52 which is omitted on its own.

[0073] Within the circular region 39 of the catheter 10, the navigation sensor 60 includes three uniaxial sensors (SAS) 64, 65, and 66. Each SAS 64, 65, and 66 may include one or more guide coils. The coils may be wound around a support member 54. Each coil may have a conductor (e.g., a wire) extending proximal therefrom. The coils and wires may be configured as presented in U.S. Patent Publication 2020 / 0015703, which is incorporated herein by reference and attached to priority application U.S. Patent Publication 63 / 220,312.

[0074] As shown in the figure, each of the SAS 64, 65, and 66 is surrounded by its respective electrodes 26A, 26E, and 26I. Thereafter, these electrodes 26A, 26E, and 26I each provide structural support to prevent bending of each of the SAS 64, 65, and 66.

[0075] The distal sensor 66, intermediate sensor 65, and proximal sensor 64 are spaced apart so that the navigation sensor 60 can determine the position of the distal section 15 in three dimensions when the distal section has a generally circular shape. Preferably, the sensors 64, 65, and 66 are spaced about 120° apart from each other when the distal section 15 has a generally circular shape; however, the sensors 64, 65, and 66 may deviate from this spacing because the circular shape is resized and / or to accommodate the placement below the electrodes 26A, 26E, and 26I. When the electrode length W1 is 3 mm, the distance W2 between the electrodes is 4 mm, and the distal section 15 is linear as shown in Figure 7, preferably the center of the distal sensor 66 is separated from the center of the central sensor 65 by about 28 mm, and the center of the central sensor 65 is separated from the center of the proximal sensor 64 by about 35 mm.

[0076] The distal section 15 further includes polymer tube sections 80, 81, 82, 83, 84, 85, 86, 87, 88, and 89 positioned on the support member 54. Most of the tube sections 83, 84, 85, 86, and 87 are positioned approximately in the center beneath their respective electrodes 26A, 26B, 26C, 26D, and 26E, thereby the ends of these tube sections intersect between these electrodes, further promoting the bending of the circular region 39 between electrodes 26A-F and relieving stress on these electrodes when the annular region 39 contracts. These tube sections 83, 84, 85, 86, and 87 preferably have a length W7 that is approximately equal to the electrode length W1 + the distance between electrodes W2 (see Figure 2C). For example, if the electrode length W1 is 3 mm and the distance between electrodes W2 is 4 mm, the tube section length W7 is preferably about 7 mm. The distal section 15 may include one or more additional tubular sections 88, 89 positioned distal to the most distal electrode 26A, providing structural support to the distal end of the circular region 39. The distal section 15 may include tubular sections 81, 82 extending beneath each of the two electrodes 26F, 26G, 26H, 26I. These longer tubular sections 81, 82 are preferably positioned proximal to the aforementioned tubular sections 83, 84, 85, 86, 87, 88, 89, and preferably have a length W7 about twice that of the shorter tubular sections 83, 84, 85, 86, 87. These longer tubular sections 81, 82 may have ends adjacent to adjacent tubular sections between electrodes to facilitate the bending of the circular region 39 between adjacent electrodes. The distal section 15 may further include a proximal tubular section 80 that extends below the proximal electrode 26J and has an end between the proximal electrode 26J and the adjacent electrode 26I. The tubular sections 80, 81, 82, 83, 84, 85, 86, 87, 88, and 89 preferably contain a polymer material.

[0077] Figure 8A illustrates the knotted cord 90 of the distal end assembly of the catheter 10. The knotted cord 90 preferably comprises an ultra-high molecular weight polymer (e.g., Vectran®) and / or high-strength braided fibers. The cord 90 comprises one or more knots 91 positioned within one or more polymer (e.g., polyimide) tubes 92.

[0078] Figure 8B is a magnified view of the distal end of the catheter 10. The cord 90 is positioned within the distal tube 52, and the non-traumatic distal tip 51 of the distal section 15 can be formed by flowing a polymer material such as polyurethane adhesive, cyanoacrylate, or epoxy into the distal end of the distal section 15. The flowed material solidifies around the knot 91 of the cord 90, conforming to the shape of the cord 90 and engaging with the knot 91. The knotted cord 90 can fix the flowed material into the distal end of the distal section 15, reducing the possibility that the non-traumatic distal tip 51 may not seat properly during manipulation of the catheter 10.

[0079] [Implementation Method] (1) A catheter, A long, slender shaft extending along the longitudinal axis, An intermediate section comprising an intermediate tube having a first plurality of lumens, which extends distally from the elongated shaft along the longitudinal axis and passes through it, A distal section comprising: a generally linear region extending distally from the intermediate section along the longitudinal axis; a circular main region distal to the generally linear region and generally perpendicular to the longitudinal axis; and a distal tube having a second plurality of lumens passing through it; The crossover region between the distal end of the intermediate pipe and the proximal end of the distal pipe, A catheter comprising: a support member mounted within the intermediate section in a first lumen of the first plurality of lumens, the support member extending through the crossover region such that it is angled with respect to the longitudinal axis, and the support member extending through the distal section in a second lumen of the second plurality of lumens which is non-coaxial with the first lumen. (2) The first plurality of lumens, and thereby the intermediate tube having four lumens, The catheter according to Embodiment 1, comprising the second plurality of lumens, thereby giving the distal tube three lumens. (3) The first plurality of lumens consist of four lumens, The catheter according to Embodiment 2, wherein the second plurality of lumens consists of three lumens. (4) The catheter according to Embodiment 1, further comprising a first pull wire extending through the intermediate section in a third lumen of the first plurality of lumens which is non-coaxial with the first lumen, wherein the first pull wire extends through the crossover region at an angle with respect to the longitudinal axis, extends through the second lumen, and is attached within the distal section in close proximity to the distal end of the circular main region. (5) The catheter according to Embodiment 4, wherein the circular main region is configured to change its diameter in response to the operation of the first pull wire.

[0080] (6) The catheter according to Embodiment 1, further comprising a second pull wire extending through a fourth lumen of the first plurality of lumens of the intermediate section and fixed within the fourth lumen, wherein the fourth lumen is non-coaxial with the first lumen and the third lumen, and the intermediate section is configured to deflect from the longitudinal axis in response to the operation of the second pull wire. (7) The catheter according to Embodiment 1, further comprising a navigation sensor assembly having a guide coil positioned within the circular main region, and a first plurality of wires extending proximal from the guide coil through a fifth lumen of a plurality of second lumens which are non-coaxial with the first lumen, wherein the first plurality of wires extend through the crossover region and through the first lumen at an angle with respect to the longitudinal axis. (8) The catheter according to Embodiment 1, further comprising electrodes distributed around the circular main region and configured to provide electrical energy for ablation of intracardiac tissue using irreversible electroporation. (9) The catheter according to embodiment 8, further comprising a second plurality of wires extending proximal to the electrode through a sixth lumen of the second plurality of lumens, wherein the second plurality of wires extend through the crossover region at an angle with respect to the longitudinal axis and extend through a seventh lumen of the first plurality of lumens which is non-coaxial with the sixth lumen. (10) The catheter according to embodiment 8, further comprising a navigation sensor assembly having the guide coils positioned within the circular main region such that each of the guide coils is surrounded by one of the electrodes.

[0081] (11) The catheter according to Embodiment 8, wherein each electrode has an outer diameter of about 8 Frenchs, a length of about 3 millimeters, and an effective surface area of ​​about 21 square millimeters. (12) The catheter according to Embodiment 8, wherein the electrodes are separated by a rim-to-rim distance of approximately 4 millimeters. (13) The catheter according to Embodiment 8, wherein the electrodes are configured to withstand 900 volts between adjacent electrodes and 1800 volts between every other electrode. (14) The catheter according to Embodiment 8, further comprising polymer tube sections, each having a length of approximately 7 millimeters, each positioned on the support member, and each centrally positioned below its respective electrode, thereby providing, with respect to at least a portion of the electrodes, a preferred bending position between the electrodes along the circular main region. (15) A distal altitude current position determination sensor mounted on the substantially linear region of the distal section, The catheter according to Embodiment 1, further comprising a proximal high current positioning sensor mounted on the intermediate section.

[0082] (16) The catheter according to Embodiment 1, wherein the support member is configured such that, within the circular main region, the flexibility in the radial direction perpendicular to the longitudinal axis is greater than the flexibility in the direction of the longitudinal axis. (17) The catheter according to embodiment 16, wherein the support member has a substantially rectangular cross-sectional shape adjacent to the distal end of the distal section and a substantially semicircular cross-sectional shape within the intermediate section. (18) The catheter according to Embodiment 17, wherein the rectangular cross-sectional shape has a height and width such that the width is at least twice the height, the width is measured substantially parallel to the longitudinal axis and the height is measured substantially perpendicular to the longitudinal axis. (19) A non-traumatic polymer dome located at the distal end of the distal section, The catheter according to Embodiment 1, further comprising: a knotted cord containing an ultra-high molecular weight polymer, positioned within the distal section, and securing the polymer dome to the distal section. (20) The catheter according to Embodiment 1, further comprising a tubular sleeve having a length of approximately 7 millimeters, which is close to the distal end of the distal section and surrounds the distal portion of the distal section, thereby suppressing the bending of the distal portion.

Claims

1. It is a catheter, A long, slender shaft extending along the longitudinal axis, An intermediate section comprising an intermediate tube having a first plurality of lumens that extends distally from the elongated shaft along the longitudinal axis and passes through it, A distal section comprising: a generally linear region extending distally from the intermediate section along the longitudinal axis; a circular main region distal to the generally linear region and generally perpendicular to the longitudinal axis; and a distal tube having a second plurality of lumens passing through it; The crossover region between the distal end of the intermediate pipe and the proximal end of the distal pipe, A support member is installed within the intermediate section in the first lumen of the first plurality of lumens, the support member extending through the crossover region such that it is angled with respect to the longitudinal axis, and the support member extending through the distal section in the second lumen of the second plurality of lumens which is not coaxial with the first lumen, The system further comprises a plurality of electrodes distributed around the circular main region and configured to provide electrical energy for ablation of intracardiac tissue using irreversible electroporation. The aforementioned circular main region has a generally circular shape formed in a plane that is generally perpendicular to the longitudinal axis, Each of the aforementioned electrodes has an outer diameter of approximately 8 French lengths, a length of approximately 3 millimeters, and an effective surface area of ​​approximately 21 square millimeters. Each of the aforementioned electrodes is separated by a distance of approximately 4 millimeters from edge to edge. The polymer tube section further comprises polymer tube sections, each having a length of approximately 7 millimeters, each positioned on the support member, and each centrally positioned below each of the electrodes, thereby providing, with respect to at least a portion of the plurality of electrodes, a preferred bending position between the plurality of electrodes along the circular main region. catheter.

2. The above-mentioned first plurality of lumens, and thereby the intermediate tube having four lumens, The catheter according to claim 1, comprising the second plurality of lumens, wherein the distal tube has three lumens.

3. The first plurality of lumens consists of four lumens, The catheter according to claim 2, wherein the second plurality of lumens consists of three lumens.

4. The catheter according to claim 1, further comprising a first pull wire extending through the intermediate section in a third lumen of the first plurality of lumens which are non-coaxial with the first lumen, wherein the first pull wire extends through the crossover region at an angle with respect to the longitudinal axis, extends through the second lumen, and is attached within the distal section in close proximity to the distal end of the circular main region.

5. The catheter according to claim 4, wherein the circular main region is configured to change its diameter in response to the operation of the first pull wire.

6. The catheter according to claim 1, further comprising a second pull wire extending through a fourth lumen of the first plurality of lumens in the intermediate section and fixed within the fourth lumen, wherein the fourth lumen is non-coaxial with the first and third lumens, and the intermediate section is configured to deflect from the longitudinal axis in response to the operation of the second pull wire.

7. The catheter according to claim 1, further comprising a navigation sensor assembly having a guide coil positioned within the circular main region, and a plurality of first wires extending proximal from the guide coil through a fifth lumen of a plurality of second lumens that are non-coaxial with the first lumen, wherein the plurality of first wires extend through the crossover region at an angle with respect to the longitudinal axis and extend through the first lumen.

8. The catheter according to claim 1, further comprising a second plurality of wires extending proximal to the plurality of electrodes through a sixth lumen of the second plurality of lumens, wherein the second plurality of wires extend through the crossover region at an angle with respect to the longitudinal axis and extend through a seventh lumen of the first plurality of lumens which is non-coaxial with the sixth lumen.

9. The catheter according to claim 1, further comprising a navigation sensor assembly having the guide coils positioned within the circular main region such that each guide coil is surrounded by one of the plurality of electrodes.

10. The catheter according to claim 1, wherein the plurality of electrodes are configured to withstand 900 volts between adjacent electrodes and 1800 volts between every other electrode.

11. A distal altitude current position determination sensor mounted on the substantially linear region of the distal section, The catheter according to claim 1, further comprising a proximal high current positioning sensor mounted on the intermediate section.

12. The catheter according to claim 1, wherein the support member is configured such that, within the circular main region, its flexibility in the radial direction perpendicular to the longitudinal axis is greater than its flexibility in the direction of the longitudinal axis.

13. The catheter according to claim 12, wherein the support member has a substantially rectangular cross-sectional shape adjacent to the distal end of the distal section and a substantially semicircular cross-sectional shape within the intermediate section.

14. The catheter according to claim 13, wherein the rectangular cross-sectional shape has a height and width such that the width is at least twice the height, the width is measured substantially parallel to the longitudinal axis and the height is measured substantially perpendicular to the longitudinal axis.

15. A non-traumatic polymer dome located at the distal end of the distal section, The catheter according to claim 1, further comprising: a knotted cord containing an ultra-high molecular weight polymer, disposed within the distal section, and securing the non-traumatic polymer dome to the distal section.

16. The catheter according to claim 1, further comprising a tubular sleeve having a length of approximately 7 millimeters, which is close to the distal end of the distal section and surrounds the distal portion of the distal section, thereby suppressing the bending of the distal portion.

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