Catheter with stretchable irrigation tube

Abstract

The present invention is entitled "A catheter with a stretchable flushing tube". In one embodiment, a medical system includes: a catheter configured for insertion into a body portion of a living subject, and comprising: a deflectable element having a distal end; an expandable distal end assembly disposed at the distal end of the deflectable element and including a plurality of electrodes, a distal portion and a proximal portion, and configured to expand from a collapsed form to an extended deployment form; and a stretchable flushing tube disposed between the distal portion and the proximal portion and including a plurality of flushing orifices, and configured to stretch longitudinally when the distal end assembly collapses from the extended deployment form to the collapsed form.

Description

Technical Field

[0001] This invention relates to medical devices, and specifically, but not exclusively, to catheters. Background Technology

[0002] Numerous medical procedures involve placing probes, such as catheters, inside a patient's body. Position sensing systems have been developed to track these probes. Magnetic position sensing is one method known in the art. In magnetic position sensing, a magnetic field generator is typically placed at a known location outside the patient's body. A magnetic field sensor within the distal end of the probe generates electrical signals in response to these magnetic fields; these signals are processed to determine the coordinate position of the distal end of the probe. These methods and systems are described in U.S. Patents 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612, and 6,332,089, in PCT International Patent Publication WO 1996 / 005768, and in U.S. Patent Application Publications 2002 / 006455, 2003 / 0120150, and 2004 / 0068178. Impedance- or current-based systems can also be used to track position.

[0003] Treatment of arrhythmias is a medical procedure in which these types of probes or catheters have proven extremely useful. Arrhythmias, and specifically atrial fibrillation, have always been a common and dangerous medical condition, especially in the elderly.

[0004] The diagnosis and treatment of cardiac arrhythmias involve mapping the electrical properties of cardiac tissue, particularly the endocardium, and selectively ablating cardiac tissue by applying energy. Such ablation can stop or alter unwanted electrical signals propagating from one part of the heart to another. Ablation methods disrupt unwanted electrical pathways by creating a non-conductive ablation focus. Various forms of energy delivery for creating ablation focuses have been disclosed, including the use of microwaves, lasers, and more commonly, radiofrequency energy to create conduction blocks along the cardiac tissue walls. In a two-step procedure (mapping followed by ablation), electrical activity at various points within the heart is typically sensed and measured by advancing a catheter containing one or more electrical sensors into the heart and acquiring data at multiple points. This data is then used to select the target endocardial region for ablation.

[0005] Electrode catheters have been widely used in medical practice for many years. They are used to stimulate and map electrical activity in the heart, as well as to ablate sites of abnormal electrical activity. In use, the electrode catheter is inserted into a major vein or artery, such as the femoral vein, and then guided to the desired cardiac chamber. A typical ablation procedure involves inserting a catheter with one or more electrodes at its distal end into the cardiac chamber. A reference electrode can be provided, typically taped to the patient's skin, or a second catheter positioned in or near the heart can be used to provide the reference electrode. RF (radio frequency) current is applied through the distal electrode of the ablation catheter, and the current flows through the medium surrounding the distal electrode—the blood and tissue between the distal and unrelated electrodes. The current distribution depends on the amount of contact between the electrode surface and the tissue compared to blood, which has a higher conductivity than tissue. Heating of the tissue occurs due to its resistance. The tissue is sufficiently heated to destroy cells in the cardiac tissue, resulting in the formation of a non-conductive ablation focus within the cardiac tissue.

[0006] U.S. Patent Publication 2019 / 0117301 by Steinke et al. describes a catheter and catheter system for treating a patient's blood vessels, comprising an elongated, flexible catheter body with a radially expandable structure. As the structure expands, multiple electrodes or other electrosurgical energy delivery surfaces can radially engage the material to be treated. A material detector near the distal end of the catheter body measures the circumferential material distribution, and a power source selectively excites the electrodes to treat the body lumen eccentrically.

[0007] U.S. Patent 9,757,180 to Gelfand et al. describes systems, devices, and methods for treating patients with sympathetic-mediated diseases that are at least partially associated with enhanced peripheral chemoreceptors or intensified sympathetic activation. These treatments involve ablation of one or more peripheral chemoreceptors or associated afferent nerves to reduce or eliminate afferent nerve signals from the peripheral chemoreceptors.

[0008] U.S. Patent 9,474,486 to Eliason et al. describes an electrophysiological catheter. In one embodiment, the catheter includes an elongated deformable shaft having a proximal end and a distal end, and a basket-shaped electrode assembly coupled to the distal end of the shaft. The basket-shaped electrode assembly has a proximal end and a distal end and is configured to present a compressed state and an expanded state. The electrode assembly also includes one or more tubular ribs and a plurality of conductors having a plurality of electrodes disposed thereon. Each of the plurality of conductors extends through the tubular rib from a corresponding electrode of the plurality of electrodes to the proximal end of the basket-shaped electrode assembly. The tubular rib is configured to present a non-planar (e.g., twisted or spiral) shape in the expanded state.

[0009] International patent publication WO 2019 / 074733 by St. Jude Medical Cardiology Div. Inc. describes a high-density mapping catheter with a mapping electrode array. These catheters can be used for the diagnosis and treatment of conditions such as cardiac arrhythmias. The catheter is adapted to contact tissue and includes a flexible frame with an electrode array. The electrode array can be formed from multiple rows of longitudinally aligned electrodes and multiple rows of transversely aligned electrodes.

[0010] U.S. Patent 10,362,952 to Basu et al. describes a catheter for diagnosing and ablating tissue, the catheter having a stable spinal electrode assembly. The stable spinal electrode assembly has at least two ridges fixed to the catheter body at their proximal ends and at least one tether fixed between distal positions of the proximal ends of adjacent ridges. The ridges have a collapsed arrangement and an expanded arrangement, in which the ridges are arranged generally along the longitudinal axis of the catheter body, and in the expanded arrangement, at least a portion of each ridge is radially outwardly bent from the longitudinal axis, and at least one tether applies tension to adjacent ridges. Summary of the Invention

[0011] According to embodiments of this disclosure, a medical system is provided, the medical system comprising: a catheter configured for insertion into a body portion of a living subject, and including: a deflectable element having a distal end; an expandable distal end assembly disposed at the distal end of the deflectable element and including a plurality of electrodes, a distal portion and a proximal portion, and configured to expand from a collapsed form to an extended deployment form; and a stretchable flushing tube disposed between the distal portion and the proximal portion and including a plurality of flushing orifices, and configured to stretch longitudinally when the distal end assembly collapses from the extended deployment form to the collapsed form.

[0012] Furthermore, according to an embodiment of this disclosure, the flushing hole is arranged radially around the flushing pipe.

[0013] Furthermore, according to the embodiments of this disclosure, the flushing hole is arranged longitudinally along the flushing pipe.

[0014] In addition, according to an embodiment of this disclosure, the flushing hole is arranged longitudinally along the flushing pipe.

[0015] Furthermore, according to embodiments of this disclosure, the system includes: an ablation power generator configured to be connected to the conduit and to apply an electrical signal to the electrode; a flushing reservoir configured to store flushing fluid; and a pump configured to be connected to the flushing reservoir and the conduit and to pump the flushing fluid from the flushing reservoir through the flushing port of the flushing tube.

[0016] Furthermore, according to embodiments of this disclosure, the relaxed state of the distal end assembly is the extended deployment form, and the distal end assembly is configured to collapse into the collapsed form when the catheter retracts into the sheath.

[0017] Furthermore, according to an embodiment of this disclosure, the relaxed state of the distal end assembly is the collapsed form, and the system further includes a pulling element disposed inside the deflectable element and the stretchable flushing tube, connected to the distal portion of the distal end assembly, and configured to extend the distal end assembly from the collapsed form to the extended deployment form when pulled.

[0018] Additionally, according to embodiments of this disclosure, the distal end assembly includes a basket-shaped assembly.

[0019] Furthermore, according to embodiments of this disclosure, the basket assembly includes a plurality of ribs.

[0020] Furthermore, according to embodiments of this disclosure, the reinforcing bar comprises nitinol.

[0021] Furthermore, according to embodiments of this disclosure, the stretchable flushing tube comprises a biocompatible stretchable material.

[0022] Additionally, according to embodiments of this disclosure, the hole includes a laser-drilled hole.

[0023] Furthermore, according to embodiments of this disclosure, the biocompatible stretchable material includes polyether block amide (PEBA).

[0024] Furthermore, according to embodiments of this disclosure, the biocompatible stretchable material is a porous material comprising cavities forming at least some of the pores.

[0025] Furthermore, according to embodiments of this disclosure, the biocompatible stretchable material includes expanded polytetrafluoroethylene (ePTFE). Attached Figure Description

[0026] The invention will be understood from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0027] Figure 1 A schematic diagram of a medical system constructed and operated according to an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of a collapsed catheter constructed and operated according to an embodiment of the present invention;

[0029] Figure 3 For deployment Figure 2A schematic diagram of the catheter;

[0030] Figure 4 for Figure 3 A sectional view of the conduit along line A:A;

[0031] Figure 5 for Figure 4 A more detailed cross-sectional view of the conduit within box A;

[0032] Figure 6 for Figure 4 A more detailed cross-sectional view of the conduit within box B;

[0033] Figure 7A A schematic diagram of a catheter in a collapsed form constructed and operated according to an alternative embodiment of the present invention; and

[0034] Figure 7B For deployment Figure 7A A schematic diagram of the catheter. Detailed Implementation

[0035] Overview

[0036] Flushing is typically used with catheters to provide cooling during medical procedures such as radiofrequency (RF) ablation. One solution for providing flushing in basket catheters is to have a flushing channel pass through the catheter, terminating in the middle of the basket. Flushing fluid can then be pumped through the flushing channel to its distal end, where it exits and provides cooling and local blood dilution to the tissue in the area of ​​the basket. However, flushing is not well-directed, and while it may be sufficient for electroporation that does not generate significant heat, it is often insufficient to reduce the heat generated during RF ablation. Another problem with basket catheters is that the basket needs to be collapsed or semi-collapsed during insertion into the body and then deployed in its expanded form within the body cavity. The need to enable the basket to collapse and expand adds another challenge to providing effective flushing, as the flushing channel can interfere with the expansion and collapse of the basket.

[0037] Embodiments of the present invention provide a conduit having an expandable distal end assembly (such as a basket-like structure) that includes electrodes thereon, wherein a stretchable flushing tube is fixed between a proximal end and a distal end of the assembly. The flushing tube includes orifices surrounding the tube to guide flushing fluid in different directions, thereby providing effective flushing and cooling. The use of a stretchable tube allows the flushing tube (and thus the flushing orifices) to extend from the proximal end to the distal end of the assembly as the tube stretches and relaxes according to the form of the assembly, such that the tube is stretched when the assembly collapses and relaxes when the assembly expands.

[0038] In some embodiments, orifices are arranged along the length of the tube and around its circumference to provide a more uniform flushing spray throughout the distal end assembly. The tube can be made of any suitable biocompatible stretchable material such as polyether block amide (PEBA) (e.g., PEBAX (Shore hardness D between 25 and 72)) or stretchable polyurethane, siloxane polymer, or expanded polytetrafluoroethylene (ePTFE). Orifices can be formed in the tube using any suitable method (e.g., but not limited to laser drilling). Some materials, such as ePTFE, may include pores formed when the material is pre-stretched or electrospun. The orifices can then provide flushing holes in the flushing tube. When there are enough orifices (e.g., a porous tube), the flushing fluid can weep from the tube instead of being sprayed. However, in many applications, providing flushing via weeping provides sufficient flushing.

[0039] In some embodiments, the distal end assembly collapses by retracting into the catheter sheath. In other embodiments, the distal end assembly has a natural collapse form, and pulling the pull cord causes the distal end assembly to expand. The pull cord may be disposed in a stretchable flushing tube and connected to the distal end of the distal end assembly.

[0040] System Description

[0041] Now for reference Figure 1 This is a schematic diagram of a medical system 20 constructed and operated according to an embodiment of the present invention. System 20 includes a catheter 40 configured for insertion into a body portion of a living subject (e.g., patient 28). Physician 30 navigates the catheter 40 (e.g., a basket catheter manufactured by Biosense Webster, Inc., Irvine, California, USA) to a target location in the heart 26 of patient 28 by manipulating an elongation-deflectable element 22 of the catheter 40 and / or deflecting it from a sheath 23 using a manipulator 32 located near the proximal end of the catheter 40. In the illustrated embodiment, physician 30 uses the catheter 40 to perform electroanatomical mapping of the cardiac chambers and ablation of cardiac tissue.

[0042] The catheter 40 includes an expandable distal end assembly 35 (e.g., a basket assembly) that is inserted through the sheath 23 in a folded configuration and only returns to its intended functional shape after the catheter 40 has exited the sheath 23. By constraining the distal end assembly 35 in a folded configuration, the sheath 23 also serves to minimize vascular trauma en route to its target location.

[0043] The catheter 40 includes multiple electrodes 48 for sensing electrical activity and / or applying ablation power to ablate tissue in body parts. A magnetic sensor (not shown) may be incorporated into the catheter 40 at the distal edge of the deflectable element 22 (i.e., at the proximal edge of the distal end assembly 35). Typically, although not strictly necessary, the magnetic sensor is a uniaxial sensor. A second magnetic sensor (not shown) may be included at any suitable location on the assembly 35. The second magnetic sensor may be a triaxial sensor (TAS), a biaxial sensor (DAS), or a SAS, based on considerations such as size. The magnetic sensor and electrodes 48 disposed on the assembly 35 are connected to various drive circuits in the console 24 via wires passing through the deflectable element 22.

[0044] In some embodiments, system 20 includes a magnetic sensing subsystem to estimate the ellipticity of the basket assembly 35 of catheter 40 and its elongation / retraction state within the heart chambers of heart 26 by estimating the elongation of the basket assembly 35 from the distance between magnetic sensors. Patient 28 is placed in a magnetic field generated by a pad containing one or more magnetic field generator coils 42, driven by unit 43. The magnetic field generated by coils 42 transmits an alternating magnetic field to the area where the body part is located. The transmitted alternating magnetic field generates a signal in the magnetic sensors indicating position and / or orientation. The generated signal is transmitted to console 24 and becomes a corresponding electrical input to processing circuitry 41.

[0045] Position and / or orientation sensing methods using external magnetic fields and magnetic sensors are implemented in various medical applications, such as those produced by Biosense-Webster. The system is implemented and described in detail in U.S. Patents 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612 and 6,332,089, PCT Patent Publication WO96 / 05768 and U.S. Patent Application Publications 2002 / 0065455A1, 2003 / 0120150A1 and 2004 / 0068178A1.

[0046] Processing circuitry 41 (typically part of a general-purpose computer) is further connected via suitable front-end and interface circuitry 44 to receive signals from body surface electrodes 49. Processing circuitry 41 is connected to body surface electrodes 49 via wires that pass through cable 39 and extend to the chest of patient 28.

[0047] In one embodiment, the processing circuit 41 presents a representation 31 of at least a portion of the catheter 40 and the calibrated body portion to the display 27 in response to the calculated position coordinates of the catheter 40.

[0048] The processing circuit 41 is typically programmed with software to perform the functions described herein. This software may be downloaded electronically to a computer via a network, or alternatively, it may be set up and / or stored on a non-transitory tangible medium (such as magnetic storage, optical storage, or electronic storage).

[0049] The medical system 20 may also include an ablation power generator 69 (such as an RF signal generator) configured to be connected to the catheter 40 and to apply an electrical signal to the electrode 48. The medical system 20 may also include: a flushing reservoir 71 configured to store flushing fluid; and a pump 73 configured to be connected to the flushing reservoir 71 and the catheter 40 and to pump flushing fluid from the flushing reservoir 71 through a flushing port of the flushing tube of the catheter 40, as referenced. Figure 2 and Figure 3 More details to follow.

[0050] Figure 1 The exemplary examples shown are chosen solely for the sake of conceptual clarity. For the sake of simplicity and clarity, Figure 1 Only elements relevant to the technology disclosed in this invention are shown. System 20 typically includes additional modules and elements that are not directly related to the technology disclosed in this invention, and therefore, these additional modules and elements are derived from... Figure 1 The corresponding descriptions are intentionally omitted. The elements of system 20 and the methods described herein can be further applied, for example, to control the ablation of tissues of the heart 26.

[0051] Now for reference Figure 2 and Figure 3 . Figure 2 A schematic diagram of a collapsible catheter 40 constructed and operated according to an embodiment of the present invention. Figure 3 For deployment in extended form Figure 2 A schematic diagram of catheter 40.

[0052] The catheter 40 is configured to be inserted into a body part of a living subject (e.g., the heart 26). Figure 1The deflectable element 22 of the conduit 40 has a distal end 33. The deflectable element 22 may be made of any suitable material, such as polyurethane or polyether block amide. Assembly 35 is disposed distal to the deflectable element 22 and may be connected to the deflectable element 22 via a proximal coupling member 50 at the distal end 33. The proximal coupling member 50 typically comprises a hollow tube and may be formed of any suitable material, such as, but not limited to, polycarbonate with or without glass filler, polyether ether ketone (PEEK) with or without glass filler, polyimide, polyamide, or polyetherimide (PEI) with or without glass filler. The coupling member 50 may be formed as an integral part of the deflectable element 22, as part of the distal end assembly 35, or as a separate element connected to both the deflectable element 22 and the distal end assembly 35.

[0053] Component 35, which may include a basket-like assembly, may include multiple ribs, such as flexible strips 55 (only one is labeled for simplicity). Figure 2 and Figure 3 In one embodiment, each flexible strip 55 includes a single electrode 48 (only some are labeled for simplicity). Component 35 may include any suitable number of electrodes 48, with each strip 55 having multiple electrodes 48.

[0054] exist Figure 2 and Figure 3 In one embodiment, each flexible strip 55 is formed of nitinol, selectively covered with insulating material in the distal and proximal regions 57 (some are only labeled for simplicity), leaving the central region 59 (some are only labeled for simplicity) of the flexible strip 55 as an electroactive region for, for example, performing mapping and / or performing ablation or electroporation. The structure of component 35 can vary. For example, the flexible strip 55 (or other ribs) may comprise a flexible printed circuit board (PCB) or a shape memory alloy such as nitinol.

[0055] By way of example only, the embodiments described herein primarily relate to the basket-shaped distal end assembly 35. In alternative embodiments, the technology disclosed herein can be used with any other suitable type of distal end assembly.

[0056] The distal end assembly 35 includes a distal portion 61 and a proximal portion 63, and is configured to collapse into a contracted form. Figure 2 (as shown) extended to extended deployment forms ( Figure 3 (As shown).

[0057] The relaxed state of the distal end assembly 35 is Figure 3 The extended deployment configuration is shown. The distal end assembly 35 is configured such that when the conduit 40 is in the sheath 23 ( Figure 1When retracted, it collapses into a collapsed form and is configured to expand into an expanded deployment form when the catheter 40 is removed from the sheath 23. The relaxed shape of the distal end assembly 35 can be set by forming a flexible strip 55 from any suitable elastic material such as nitinol or PEI.

[0058] The conduit 40 includes a stretchable flushing tube 65 disposed between the distal portion 61 and the proximal portion 63. The stretchable flushing tube 65 includes a plurality of flushing holes 67 (some are labeled for simplicity) and is configured to stretch longitudinally when the distal end assembly 35 collapses from an extended deployment form to a collapsed form. The stretchable flushing tube 65 comprises a biocompatible stretchable material, such as polyether block amide (PEBA) (e.g., PEBAX (Shore hardness D between 25 and 72-55D) or stretchable polyurethane, siloxane polymer, or expanded polytetrafluoroethylene (ePTFE). The stretchable flushing tube 65 may have any suitable dimensions, for example, an outer diameter ranging from 0.5 mm to 3 mm, such as 1.5 mm, and a wall thickness ranging from 0.01 mm to 0.5 mm, such as 0.125 mm. The orifice 67 may have any suitable diameter, for example, ranging from about 0.01 mm to about 0.2 mm, such as about 0.165 mm. The tube 65 may include any suitable number of discrete orifices, for example, between 1 and 200, such as 50. For clarity, the stretchable flushing tube 65 is... Figure 3 The stretchable flushing tube 65 is shown as transparent. Alternatively, the stretchable flushing tube 65 may be translucent or opaque, or any suitable combination thereof. Pump 73 ( Figure 1 It is configured to pump flushing fluid from flushing reservoir 71 through flushing port 67 of flushing pipe 65.

[0059] In some embodiments, flushing holes 67 are radially disposed around and / or longitudinally disposed along flushing tube 65. In other embodiments, flushing holes 67 may be configured such that each hole 67 extends at an angle relative to the longitudinal axis. In one embodiment, each hole may extend at an angle of approximately 90 degrees relative to the longitudinal axis LL, such that the hole is orthogonal to the longitudinal axis LL. The orientation of the flushing holes 67 is a typical orientation (typically not parallel to the longitudinal axis LL) to ensure that the electrode is adequately covered by the flushing flow, therefore each flushing hole 67 may not have the same orientation as its neighbor.

[0060] In some embodiments, the hole 67 may include a laser- or mechanically drilled hole. For example, a laser-drilled hole may be formed in a biocompatible stretchable material, such as PEBA. In some embodiments, the biocompatible stretchable material (e.g., ePTFE) is a porous material that includes cavities forming at least some of the holes in the hole 67.

[0061] Now for reference Figure 4 , it is Figure 3 A cross-sectional view of the conduit 40 along line C:C. Figure 4 (Inside box A) is shown the distal end (only two are labeled for simplicity) of a flexible strip 55 folded over and connected to a distal connector 75. In some embodiments, the distal connector is a tube (e.g., a polymer tube) or a strip (e.g., a polymer strip). The distal end of a stretchable flushing tube 65 is connected to the distal connector 75. Reference Figure 5 The distal connector 75 is described in more detail.

[0062] In some implementations, the flexible strip 55 can be connected to the distal connector 75 without folding over, such that when the distal end assembly 35 collapses, the flexible strip 55 forms a nearly flat shape along its length.

[0063] Figure 4 (Inside box B) is shown the proximal end of the flexible strip 55 connected to the proximal coupling member 50. The proximal end of the stretchable flushing tube 65 is connected to (e.g., stretched over) a proximal connector 77 (e.g., a polymer insert). Reference Figure 6 The proximal connector 77 is described in more detail. Figure 4 Also shown is a flushing line 79 (which extends through a slot 83 in the deflectable element 22, the proximal coupling member 50, and the proximal connector 77) and a position sensor 81 (e.g., a magnetic position sensor).

[0064] Now for reference Figure 5 , it is Figure 4 A more detailed cross-sectional view of the conduit 40 inside frame A. The distal end of the stretchable flush tube 65 is connected to the distal connector 75. A flexible strip 55 is secured between the stretchable flush tube 65 and the distal retaining ring 85. An adhesive or epoxy layer 86 is disposed between the distal retaining ring 85 and the flexible strip 55, thereby securing the retaining ring 85 to the flexible strip 55. Pressure and / or any suitable adhesive can be used to secure the stretchable flush tube 65 and the flexible strip 55. The distal connector 75 and the proximal retaining ring 85 can be formed of any suitable material, such as, but not limited to, polycarbonate with or without glass filler, PEEK with or without glass filler, or PEI with or without glass filler. The distal connector 75 also serves as a insert to plug the distal end of the stretchable flush tube 65.

[0065] Now for reference Figure 6 , it is Figure 4 A more detailed sectional view of the conduit 40 inside frame B.

[0066] Figure 6A proximal connector 77 with a slot 83 is shown. The slot 83 allows a flush line 79-3 and wires (e.g., for connection to one or more electrodes and / or sensors) to traverse the proximal connector 77. A flush line 79-2 is connected to the flush line 79-3, and this flush line is narrower so that it fits into the slot 83. A stretchable flush tube 65 is connected to the proximal connector 77 and is shown stretched over the proximal connector 77. The stretchable flush tube 65 can be connected to the proximal connector 77 using any suitable connection method. A proximal retaining ring 87 is disposed around the stretchable flush tube 65 to assist in securing the stretchable flush tube 65 to the proximal connector 77. Figure 6 The stretchable tube 65 is shown partially in an "unstretched" configuration, meaning that tube 65 does not elongate along the longitudinal axis LL. Figure 7B In the unstretched configuration of tube 65, flushing hole 67 is preferably in the form of a generally circular opening with a diameter of about 0.165 mm.

[0067] The proximal end of the flexible strip 55 is secured between the proximal connecting member 50, the position sensor 81, and the flushing line 79-2. Another retaining ring 89 is secured to the proximal connecting member 50 to assist in securing the flexible strip 55 to it. The flexible strip 55 can be secured to the proximal connecting member 50 using pressure and / or any suitable adhesive.

[0068] The distal connector 77, proximal retaining ring 87, and retaining ring 89 may be formed of any suitable material, such as, but not limited to, polycarbonate with or without glass filler, PEEK with or without glass filler, or PEI with or without glass filler.

[0069] Now for reference Figure 7A and Figure 7B . Figure 7A A schematic diagram of a collapsible catheter 100 constructed and operated according to an alternative embodiment of the present invention. Figure 7B For deployment and expansion Figure 7A A schematic diagram of the conduit 100, which has a larger outer profile than in the collapsed configuration of the conduit 100. In the collapsed configuration of the basket-shaped conduit 100, the tube 65 is in a "stretched" configuration (designated as an elongated tube 65'), which elongates the tube 65 by approximately 80% of its initial unstretched length to achieve an elongated tube 65' longer than the unstretched length of the tube 65. In this configuration, in Figure 7A As can be seen in the illustration, due to the elongation of tube 65', the elongation of tube 65' causes ( Figure 6 The circular flushing hole 67 has a slot-shaped (i.e., rounded rectangle) perimeter 67' of approximately 0.15 mm by 0.5 mm (e.g., the area of ​​the opening 67' is increased by approximately 250% over the area of ​​the initial opening 67). Figure 7B In the extended configuration of the basket-like body 100 shown, the tube 65 is not stretched along the longitudinal axis LL as illustrated in the schematic diagram of the tube 65. Figure 7B In the unstretched tube configuration 65, the flushing hole 65 has an approximately circular opening to allow flushing fluid to flow through. In one embodiment, the unstretched length of the tube 65 is approximately 6 mm, and the elongated length 65' (of the initial tube 65) is approximately 11 mm.

[0070] Apart from the following differences, catheter 100 and Figures 1-6 The catheter 40 is essentially the same. The relaxed state of the distal end assembly 35 of the catheter 100 is as follows: Figure 7A The collapsed form of the distal end assembly 35, as shown, and the relaxed state of the basket 100, cause the stretchable tube 65' to stretch or elongate. This relaxed state can be constructed using elastic materials such as PEI or shape memory alloys such as nitinol.

[0071] The catheter 100 includes a traction element 102 (e.g., a traction wire) disposed within the deflectable element 22 and the stretchable flushing tube 65, and connected to the distal portion 61 of the distal end assembly 35. The traction element 102 may be formed of any suitable material, such as stainless steel, nitinol, and / or ultra-high molecular weight polyethylene (UHMWPE). The traction element 102 may have any suitable outer diameter, for example, in the range of 0.05 mm to 0.5 mm, such as 0.175 mm. In some embodiments, the traction element 102 is connected to a distal connector 75. The traction element 102 is configured to cause the distal end assembly 35 to shift from a collapsed form when pulled. Figure 7A (as shown) extended to extended deployment forms ( Figure 7B (As shown). The traction element 102 can be connected to the manipulator 32 ( Figure 1 The manipulator controls the pulling element 102 to deploy the assembly 35 and changes the ellipticity of the assembly 35 according to the longitudinal displacement of the pulling element 102 relative to the deflectable element 22.

[0072] As used herein, the term “about” or “approximately” for any numerical value or range indicates appropriate dimensional tolerances that allow a collection of parts or components to achieve the intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of values ​​±20% of the listed values; for example, “about 90%” may refer to a range of values ​​from 72% to 108%.

[0073] For clarity, the various features of the invention described in the context of individual embodiments may also be provided in combination in a single embodiment. Conversely, for brevity, the various features of the invention described in the context of individual embodiments may also be provided individually or in any suitable sub-combination.

[0074] The above embodiments are cited by way of example, and the invention is not limited to the specific examples shown and described above. Rather, the scope of the invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which will occur to those skilled in the art upon reading the above description and are not disclosed in the prior art.

Claims

1. A medical system comprising a catheter configured for insertion into a body portion of a living subject, and further comprising: A deflectable element having a distal end; An expandable distal end assembly is disposed at the distal end of the deflectable element and includes multiple electrodes, a distal portion and a proximal portion, and is configured to expand from a collapsed form to an extended deployment form. as well as A stretchable flushing tube is disposed between the distal portion and the proximal portion and includes a plurality of flushing holes, and is configured to stretch longitudinally when the expandable distal end assembly collapses from the expanded deployment form to the collapsed form.

2. The system of claim 1, wherein the flushing holes are arranged radially around the flushing pipe.

3. The system according to claim 2, wherein the flushing hole is arranged longitudinally along the flushing pipe.

4. The system according to claim 1, wherein the flushing hole is arranged longitudinally along the flushing pipe.

5. The system according to claim 1, further comprising: An ablation power generator is configured to be connected to the catheter and to apply an electrical signal to the electrode; A flushing reservoir configured to store flushing fluid; as well as A pump configured to connect to the flush reservoir and the conduit, and to pump the flush fluid from the flush reservoir through the flush port of the flush conduit.

6. The system of claim 1, wherein the relaxed state of the scalable distal end assembly is the extended deployment form, and the scalable distal end assembly is configured to collapse into the collapsed form when the catheter retracts into the sheath.

7. The system of claim 1, wherein the relaxed state of the expandable distal end assembly is the collapsed form, the system further comprising a pulling element disposed within the deflectable element and the stretchable flushing tube and connected to the distal portion of the expandable distal end assembly, and configured to extend the expandable distal end assembly from the collapsed form to the extended deployment form when pulled.

8. The system of claim 1, wherein the scalable distal end assembly comprises a basket assembly.

9. The system of claim 8, wherein the basket assembly comprises a plurality of ribs.

10. The system of claim 9, wherein the reinforcing rib comprises nitinol.

11. The system of claim 1, wherein the stretchable flushing tube comprises a biocompatible stretchable material.

12. The system of claim 11, wherein the flushing hole comprises a laser-drilled hole.

13. The system of claim 11, wherein the biocompatible stretchable material comprises polyether block amide (PEBA).

14. The system of claim 11, wherein the biocompatible stretchable material comprises a porous material, the porous material comprising cavities forming at least some of the flushing holes.

15. The system of claim 14, wherein the biocompatible stretchable material comprises expanded polytetrafluoroethylene (ePTFE).

16. A catheter device, comprising: A deflectable element having a distal end; An expandable distal end assembly is disposed at the distal end of the deflectable element and includes a plurality of electrodes and a distal portion extending along a longitudinal axis to a proximal portion, the distal end being configured to expand from a collapsed form to an extended deployment form. as well as A stretchable flushing tube is disposed along the longitudinal axis between the distal portion and the proximal portion, and includes a plurality of flushing holes extending through the stretchable flushing tube in a direction not parallel to the longitudinal axis, the stretchable flushing tube being configured to stretch to an elongated length along the longitudinal axis when the expandable distal end assembly collapses.

17. The conduit device of claim 16, wherein when the stretchable flushing tube is in a first configuration having an unstretched length shorter than the elongated length, each of the plurality of flushing holes defines a circular periphery.

18. The conduit device of claim 16, wherein when the stretchable flushing tube is stretched to the elongated length, each of the plurality of flushing holes defines a rounded rectangular perimeter.

19. The catheter device of claim 16, wherein the elongated length includes any length that is 20% to 80% greater than the unstretched length of the stretchable flushing tube.

20. The catheter of claim 16, wherein the flushing port extends substantially orthogonally to the longitudinal axis.

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