Seal and reinforcement for perfusion electrophysiology balloon catheter with flexible circuit electrodes

Abstract

The invention is entitled "Seals and Reinforcements for Perfusion Electrophysiology Balloon Catheter with Flexible Circuit Electrodes." A perfusion electrophysiology balloon catheter with flexible circuit electrodes is disclosed. To help prevent fluid (e.g., irrigation fluid or air) from passing between the spaces between the inner and outer tubular shafts of the catheter, a first seal and a second seal can be provided around the inner tubular shaft from the location where the outer tubular shaft emerges. The material and dimensions of these seals help ensure that the seals are sufficiently robust so that they do not fail during use of the catheter. Additionally, the flexible circuit electrodes can include substrates that are adhered to the balloon. Delamination of these substrates can be prevented by use of a reinforcement member that extends the length of the balloon.

Description

[0001] Cross-references to patent applications

[0002] This patent application claims priority to U.S. Provisional Patent Application 62 / 900,129, filed September 13, 2019, pursuant to 35:119 of the United States Code. This application also relates to the subject matter described in U.S. Patent Application 15 / 360,966, filed November 23, 2016; U.S. Patent Application 15 / 939,154, filed March 28, 2018; and U.S. Patent Application 16 / 432,392, filed June 5, 2019. The entire contents of the patent applications listed in this paragraph are incorporated herein by reference. Technical Field

[0003] The topics disclosed in this article relate to ablation systems, particularly those that include catheters capable of ablating cardiac tissue and graphical user interface systems for assisting in the execution of ablation. Background Technology

[0004] Ablation of cardiac tissue has been used to treat arrhythmias. Ablation energy is typically delivered to the cardiac tissue via a distal portion that travels along the tissue to be ablated. Some of these catheters apply ablation energy via various electrodes positioned within or incorporated into three-dimensional structures such as wire cages and balloons. Summary of the Invention

[0005] This invention discloses a perfusion-type electrophysiological balloon catheter with flexible circuit electrodes. The catheter may include an outer tubular shaft having an outer surface, a first lumen configured to pass through the outer tubular shaft, and a second lumen configured to pass through the outer tubular shaft. It may also include an inner tubular shaft having an outer surface disposed within the first lumen of the outer tubular shaft and having a distal portion extending beyond the distal portion of the outer tubular shaft. A catheter balloon may also be provided. The catheter balloon may include a membrane having a first end and a second end, the first end being connected to the outer surface of the outer tubular shaft around the distal portion of the outer tubular shaft, and the second end being connected to the outer surface of the distal portion of the inner tubular shaft. Therefore, the distal segment of the inner tubular shaft may be disposed within the balloon.

[0006] To help prevent fluids (e.g., flushing fluid or air) from passing through the space between the inner and outer tubular shafts, a first seal and a second seal are also provided around the inner tubular shaft where it emerges from the outer tubular shaft. The materials and dimensions of these seals help ensure that they are robust enough to not fail during the use of the conduit.

[0007] The flexible circuit electrodes can include substrates disposed on the balloon. Delamination of these substrates can be prevented by using a reinforcement member component, such as liquid crystal polymer (LCP) or ultra-high molecular weight polyethylene (UHMWPE) yarn, that extends the length of the balloon. BRIEF DESCRIPTION OF DRAWINGS

[0008] While the claim particularly pointing out and distinctly claiming the subject matter recited herein is set forth in the concluding portion of this specification, it is believed that this subject matter can be better understood from the following description in conjunction with the accompanying drawings in which like reference characters refer to the same elements and in which:

[0009] Figure 1 schematic view of an invasive medical procedure;

[0010] Figure 2 schematic view of the top of a catheter having a balloon in an inflated state;

[0011] Figure 3 schematic view of a balloon of Figure 2 along with a lasso catheter;

[0012] Figure 4 schematic view of a distal end of a catheter of Figure 2 deployed in the region of a pulmonary vein and its ostium;

[0013] Figure 5 schematic view of a cross-section of a solid model of a balloon of Figure 2 including a first seal;

[0014] Figure 6 schematic view of a cross-section of a first seal;

[0015] Figure 7 schematic view of a cross-section of a solid model of a portion of a handle of a catheter of Figure 2 including a second seal.

[0016] Figure 8 schematic view of a cross-section of a solid model of a second seal;

[0017] Figure 9 schematic view of a perspective view of a solid model of a second seal;

[0018] Figure 10 schematic view of a cross-section of a second seal; and

[0019] Figure 11 schematic view of an image of a substrate of a balloon of Figure 2 having a reinforcement member component. DETAILED DESCRIPTION

[0020] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are identically numbered. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the application. The detailed description illustrates by way of example, not by way of limitation, the principles of the application. This description will clearly enable one skilled in the art to make and use the application, and describes several embodiments, adaptations, variations, alternatives, and uses of the same, including what is presently believed to be the best way to implement the application.

[0021] As used herein, the term "about" or "approximately," with reference to any numerical or range of numbers, indicates suitable dimensional tolerances that allow the components or elements, to which the term refers, to perform their intended purpose. More specifically, "about" or "approximately" can refer to a range of values ±10% of the recited value, for example, "about 90%" can refer to a range of values from 81% to 99%. Additionally, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject and are not intended to limit the systems or methods to human use, although use of the subject application in human patients is a preferred embodiment.

[0022] System description

[0023] Figure 1 is a schematic illustration of an invasive medical procedure using the apparatus 12 according to one embodiment. The procedure is performed by a medical professional 14, and by way of example, it is assumed that the procedure in the following description includes ablating a portion of myocardium 16 of a heart of a human patient 18. However, it should be understood that the embodiments disclosed herein are not limited to only this particular procedure, but can include substantially any procedure on biological tissue or non-biological material.

[0024] To perform the ablation, the medical professional 14 inserts the probe 20 into a sheath 21 that has been pre-positioned in a body lumen of the patient. The sheath 21 is positioned such that the distal end of the probe 20 enters the heart of the patient. In the following, reference is made to the heart of the patient, but it should be understood that the embodiments disclosed herein are not limited to only this particular procedure, but can include substantially any procedure on biological tissue or non-biological material. Figure 2 The detailed diagnostic / treatment catheter 24, e.g., a balloon catheter, is deployed to pass through the lumen of the probe 20 and exit from the distal end of the probe 20.

[0025] As Figure 1As shown, device 12 is controlled by system processor 46, which is located in the device's operating console 48, also schematically shown at reference numeral 15. Console 48 includes controls 49 for communication with the processor by a medical professional 14 and a screen 62. Thus, screen 62 may include a touchscreen, and controls 49 may include, for example, a mouse or trackball. During the procedure, processor 46 typically uses any method known in the art to track the position and orientation of the distal end of probe 20. For example, processor 46 may use a magnetic tracking method, in which magnetic transmitters 25X, 25Y, and 25Z, located outside the patient 18, generate signals in coils positioned in the distal end of probe 20. The system (purchased from Biosense Webster, Inc. of Irvine, California) uses this type of tracing method.

[0026] Software for processor 46 can be downloaded electronically to the processor, for example, via a network. Alternatively or otherwise, the software can be provided via a non-transitory tangible medium such as optical, magnetic, or electronic storage media. Tracking of the distal end of probe 20 can be displayed on a three-dimensional representation 60 of the heart of patient 18 on screen 62. However, it can be displayed in two dimensions, for example, via fluoroscopic examination or MRI.

[0027] To operate device 12, processor 46 communicates with memory 50, which has multiple modules used by the processor to operate the device. Therefore, memory 50 includes a temperature module 52, an ablation module 54, and an electrocardiogram (ECG) module 56. Memory 50 typically includes other modules such as a force module for measuring forces on the distal end of probe 20, a tracking module for operating the tracking method used by processor 46, and a flushing module 53 connected to a pump, thereby allowing the processor to control the pump and thus control the flushing supplied to the catheter. For simplicity, Figure 1Other modules of this kind are not shown. This module may include hardware and software elements. For example, module 54 may include a radio frequency generator having at least one output or output channel (e.g., ten outputs or ten output channels). Each of the outputs can be individually and selectively activated or deactivated by a switch. That is, each switch may be positioned between the signal generator and the corresponding output. Thus, a generator with ten outputs would include ten switches. These outputs can each be individually coupled to electrodes on the ablation catheter, such as the ten electrodes 33 on balloon 80, as described in further detail below. This electrical connection can be achieved by establishing an electrical path between each output and each electrode. For example, each output can be connected to the corresponding electrode via one or more wires or suitable electrical connectors. Thus, in some embodiments, the electrical path may include at least one wire. In some embodiments, the electrical path may also include an electrical connector and at least a second wire. Thus, electrodes 33 can be selectively activated and deactivated by switches to receive radio frequency energy independently of each of the other electrodes.

[0028] Figure 2 This is a schematic perspective view of the diagnostic / therapeutic catheter 24, with the balloon 80 in an inflated configuration. The catheter 24 may include a handle 27, a knob 28, controls 37, and a flushing lumen 29. The knob 28 can be used to advance and retract the distal liner 88 to change the configuration of the balloon 80 between an inflated and collapsed configuration, as further described below. Flushing lumen (see below) Figure 5 A second lumen (referred to as second lumen 112) passes through catheter 24 and a tube 29 is connected to balloon 80, such that flushing fluid (e.g., saline) can be introduced or pumped through tube 29 and ultimately enter balloon 80 via a pump connected to the flushing fluid source and flushing module 53. Control 37 can be used to further manipulate or control portions of catheter 24, such as by deflecting the distal portion of catheter 24.

[0029] Further reference Figure 3 , Figure 4 and Figure 5The diagnostic / therapeutic catheter 24 is used to ablate the orifice 11 of an inner lumen (such as the pulmonary vein 13). The proximal end (or first end) of the balloon 80 may be supported on the distal end of the outer tubular shaft 70, for example, by compression of it with a bushing 71, which may also serve as an annular electrode. The outer tubular shaft 70 terminates in the balloon at an outer shaft opening 73. The inner tubular shaft 82 may be configured to pass through the outer tubular shaft 70 such that it extends into the balloon 80 via the outer shaft opening 73. The distal end (or second end) of the balloon 80 may be attached to the distal end of the inner tubular shaft 82 by compression of it with a bushing 88, which may serve as an annular electrode. Another catheter, such as a lasso catheter 72, may pass through the inner tubular shaft 82 to extend into the bushing 88. The outer tubular shaft 70, the inner tubular shaft 82, and the lasso catheter 72 may be arranged in a telescoping overlapping relationship relative to each other. However, the relative movement between the outer tubular shaft 70 and the inner tubular shaft 82 is limited by the fact that the balloon 80 is connected to the outer tubular shaft 70 at its proximal end or first end, and to the inner tubular shaft 82 at its distal end or second end. This relative movement allows for manipulation of the shape of the balloon 80. Specifically, when the length of the inner tubular shaft 82 extending from the outer tubular shaft 70 is maximized, the balloon 80 has a rectangular shape, i.e., a collapsed configuration, while when the length of the inner tubular shaft 82 extending from the outer tubular shaft 70 is minimized, the balloon 80 has a spherical shape, i.e., an inflated configuration, as reflected in the figure. This relative movement can be achieved by manipulating the knob 28 on the handle 27 to move the inner tubular shaft 82 relative to the outer tubular shaft 70.

[0030] The balloon 80 of the diagnostic / therapeutic catheter 24 is made of a biocompatible material (e.g., made of polyethylene terephthalate (PET), polyurethane, or...). The outer wall, surface, or membrane 26 of the balloon 80 is made of a plastic material. An outer tubular shaft 70 defines the longitudinal axis 78 of the balloon 80. The balloon 80 is deployed in a collapsed configuration via the lumen 23 of the probe 20 and can inflate after exiting the distal end, as described above. The membrane 26 of the balloon 80 may be formed with flushing orifices or flushing holes 35 through which fluid (e.g., saline) can be drained from the interior of the balloon 80 to the exterior for use at the tissue ablation site at the cooling port. Although... Figure 2 and Figure 4 The fluid exiting the balloon 80 as a jet is shown, but the fluid can exit the balloon at any desired flow rate or pressure, including the rate at which fluid leaks from the balloon.

[0031] The membrane 26 supports and carries the combined electrodes and temperature sensing components, each configured as a multilayer flexible circuit electrode assembly 84. The "flexible circuit electrode assembly" 84 can have many different geometries. In an illustrated embodiment, the flexible circuit electrode assembly 84 has a plurality of radiating substrates or strips 30 on which electrodes 33 are disposed. In the embodiment reflected in the figures, one electrode 33 is disposed on each of the substrates 30. Thus, for example, in the case where the balloon 80 includes ten substrates, the balloon also includes ten electrodes. The substrates 30 are uniformly distributed around the distal end 88 and the balloon 80. Each substrate has a wider proximal portion that tapers gradually to a narrower distal portion. Additionally, each substrate extends from a first end of the balloon 80 at the bushing 71 to a second end of the balloon 80 at the bushing 88.

[0032] Fluid management

[0033] The applicant has determined that various fluid management factors must be considered to avoid malfunctions and enable the catheter 24 to be used in a clinical setting. For example, due to the telescoping relationship between the outer tubular shaft 70 and the inner tubular shaft 82, a space exists between them. Without explanation, air may enter this space through the handle 27 and into the balloon 80. Additionally, flushing fluid in the balloon 80 may enter this space via the outer shaft opening 73 in the balloon 80, where the inner tubular shaft 82 extends beyond the outer tubular shaft 70. Therefore, the applicant has designed a seal that prevents fluid from entering the space between the inner tubular shaft 82 and the outer tubular shaft 70, but does not impede the telescoping function of the inner tubular shaft 82 and the outer tubular shaft 70, and is sufficiently robust to prevent fluid ingress, thereby enabling at least five and up to twenty rounds of inflation and collapse of the balloon 80 through the telescoping function provided by the inner tubular shaft 82 and the outer tubular shaft 70. The applicant has determined that the following characteristics may affect the robustness of the seal: 1) friction may cause the seal to clump together around the inner tubular shaft 82 and fail as it moves back and forth within the outer tubular shaft 70; 2) repeated back-and-forth movement may cause wear on the support surfaces of the seal, and this wear may lead to leakage; and 3) the seal must withstand the pressure generated inside the balloon 80 by allowing flushing fluid to flow therein. Based on these and other characteristics of the conduit 24, the applicant has designed two different seals: a first or distal seal 100 disposed in the balloon 80 to prevent backflow of flushing fluid, and a second or proximal seal 200 disposed in the handle 27 to prevent air ingress.

[0034] refer to Figure 5 and Figure 6A first seal 100 is described. The first seal 100 is disposed around the distal section 102 of the inner tubular shaft 82. Thus, the first seal 100 may have a tubular configuration or at least a circular inner surface to surround the distal section 102.

[0035] A connector component 108 may also be provided. The connector component 108 is also essentially tubular, allowing it to be attached to the distal portion of the outer tubular shaft 70, and making the connector 108 a characteristic structure of the outer tubular shaft 70. Thus, the proximal end or first end of the balloon 80 can be attached to the outer tubular shaft 70 via or in combination with the connector using, for example, the techniques described above. Therefore, the inner tubular shaft 82 extends into the balloon 80, passing through the outer tubular shaft 70 and the connector 108 in region 110 of the balloon 80.

[0036] Between region 110 and bushing 71, i.e., only proximal to region 110, the flushing lumen or second lumen 112 of the outer tubular shaft 72 terminates at termination point 113 at the distal end of the outer tubular shaft 72 or through a sidewall adjacent to the distal end of the outer tubular shaft, or a combination thereof. Therefore, connector 108 may be provided with at least one port or window 114 through sidewall 115, wherein window 114 is positioned adjacent to termination point 113, thereby exposing termination point 113 to the interior of balloon 80. This allows flushing fluid pumped through the second lumen 112 to flow into balloon 80 via window 114. Figure 5 As shown, there are two instances of window 114.

[0037] The flushing fluid entering the balloon 80 through window 114 pressurizes the balloon 80, thereby tauting its outer surface 26. Therefore, the pressure inside the balloon 80 is greater than the pressure in the space between the outer tubular shaft 70 and the inner tubular shaft 82, thus creating the need for the first seal 100.

[0038] The first seal 100 may mate with the connector 108 in the region 110 where the inner tubular shaft 82 is exposed. The applicant has determined that the following characteristics are important for manufacturing a robust first seal 100.

[0039] The first seal 100 preferably includes a distal first sealing portion 104 made of a first material and a proximal first sealing portion 106 made of a second material. The first material and the second material may be different from each other. The first material may comprise: 1) a thermoplastic elastomer PEBAX manufactured by Arkema. TM It consists of polyamide and polyether backbone blocks; 2) barium sulfate; 3) PROPELL, a low-friction compound manufactured by Foster. TM; or 4) any combination thereof. In a preferred embodiment, the first material may comprise about 76% PEBAX 3533SA 01MED, about 20% barium sulfate, and about 4% PROPELL. The second material may comprise polyamide manufactured by Evonik. Such as VESTAMID CARE ML21.

[0040] refer to Figure 6 The distal first sealing portion 104 has: 1) a pre-assembled wall thickness F between about 0.00375 inches and about 0.00750 inches, for example, about 0.00525 inches; and 2) a pre-assembled inner diameter E between about 0.055 inches and about 0.065 inches, for example, about 0.061 inches. The proximal first sealing portion 106 has: 1) a pre-assembled wall thickness C between about 0.003 inches and about 0.005 inches, for example, about 0.00375 inches; and 2) a pre-assembled inner diameter B between about 0.0064 inches and about 0.0068 inches, for example, about 0.0655 inches. As used herein, the term “pre-assembled” indicates the characteristics of a component before it is assembled into the conduit, because pre-assembled characteristics, especially pre-assembled dimensions, are used to procure materials and determine that they are supplied according to the corresponding product specifications.

[0041] The aforementioned material selection and dimensions ensure that the frictional fit between the first seal 100 and the inner tubular shaft 82 does not impede the telescopic overlapping movement of the inner tubular shaft 82 within the outer tubular shaft 70, and that the distal section 102 of the inner tubular shaft 82 has an outer diameter greater than or equal to the pre-assembled inner diameter E of the distal first sealing portion. Depending on the pressure generated within the balloon 80, it may sometimes be recommended that the distal section 102 of the inner tubular shaft 82 have an outer diameter greater than or equal to the pre-assembled inner diameter B of the proximal first sealing portion.

[0042] To substantially cover the distal segment 102, the first seal 100 may be between about 10 mm and about 25 mm in length, for example, about 23 mm. Furthermore, the first seal 100 should be shorter than the distal segment 102 to avoid interference that might otherwise occur between, for example, the first seal 100 and the bushing 88 during the assembly of the conduit 24. However, the lengths of the distal first sealing portion 104 and the proximal first sealing portion 106 differ based on the interactions between the aforementioned dimensions and materials, and the various properties (e.g., friction) they impart to the seal 100 on the distal segment 102. Therefore, the length G of the distal first sealing portion may be between about 0.09 inches and about 0.13 inches, for example, 0.11 inches.

[0043] Now for reference Figures 7 to 10The second seal 200 is described. The inner tubular shaft 82 can telescopically overlap within the outer tubular shaft 70. Furthermore, the proximal portion 204 of the inner tubular shaft 82 extends beyond the proximal portion 202 of the outer tubular shaft 70. The second seal 200 is positioned around the proximal portion 204 of the inner tubular shaft 82 extending beyond the proximal portion 202 of the outer tubular shaft 70.

[0044] The second seal 200 may be tubular, comprising a proximal segment 206 and a distal segment 208. The distal segment 208 may be secured to the outer surface 210 of the outer tubular shaft 70. Additionally, the proximal segment 206 may be positioned to contact the outer surface 212 of the inner tubular shaft 82. The outer diameter N of the proximal segment 206 of the second seal 200 is approximately equal to the outer diameter of the distal segment 208 of the second seal 200. Furthermore, the pre-assembled inner diameter I of the proximal segment 206 may be smaller than the pre-assembled inner diameter H of the distal segment 208 of the second seal to allow a seal to be formed around the position of the inner tubular shaft 82 entering the outer tubular shaft 70, while leaving a gap in the distal segment 208 for securing the distal seal 200 to the outer tubular shaft 70. Therefore, the pre-assembled inner diameter I of the proximal segment 206 may be less than or equal to the outer diameter of the segment of the inner tubular shaft 82 configured to pass through the proximal segment 206. More specifically: 1) the pre-assembled inner diameter I of the proximal segment 206 may be between about 0.058 inches and about 0.066 inches, for example, about 0.062 inches; 2) the pre-assembled inner diameter H of the distal segment 208 may be between about 0.075 inches and about 0.08 inches, for example, 0.078 inches; 3) the wall thickness K of the proximal segment 206 may be between about 0.04 inches and about 0.045 inches, for example, about 0.0425 inches; and 4) the wall thickness J of the distal segment 208 may be between about 0.03 inches and about 0.04 inches, for example, about 0.035 inches.

[0045] The second seal 200 may be made of siloxane, such as Dow Corning. Made of Q7-6860. A tube 214, made of, for example, polyimide, can be used to secure the outer surface 210 of the outer tubular shaft 70 to the distal segment 208 of the seal 200. Thus, the tube 214 can be at least partially disposed in the distal segment of the second seal and surround the outer tubular shaft.

[0046] Reinforcement

[0047] Through ongoing research and product development work on the aforementioned subject, the applicant has determined that the balloon 80 must be able to withstand multiple cycles of deployment from the lumen 23 of the probe 20 in a collapsed configuration, expansion to an expanded configuration, return to a collapsed configuration, and withdrawal back into the lumen 23 of the probe 20. The number of cycles can be approximately five to approximately twenty. That is, the connection between the base 30 and the outer surface 26 of the balloon 80, as well as the overall integrity of the assembled balloon, must withstand at least five to twenty fatigue cycles, plus any additional frictional stress experienced during approximately five to approximately twenty deployments from the lumen 23 and five to twenty withdrawals back into the lumen. To help prevent possible delamination of the base 30 from the outer surface 26 (which could be caused by repeated fatigue), the applicant has therefore implemented a solution that will prevent or at least significantly further reduce the likelihood of any such delamination. The applicant also determined that any such solution would need to accommodate various design constraints, such as: 1) minimizing the associated safety issues arising from any solution; 2) minimizing any increase in the diameter of the portions of balloon 80 to which the base 30 is adhered, such that balloon 80 in a collapsed configuration can be easily deployed from and withdrawn from lumen 23 with little or no increase in friction (or, especially in extreme cases, avoiding the need to increase the diameter of lumen 23); 3) minimizing any increase in the stiffness of balloon 80 that could impede the establishment of contact between electrode 30 and tissue during surgery; 4) not impeding electrical contact between electrode 33 and tissue during surgery; and 5) minimizing the increase in the number of assembly steps.

[0048] refer to Figure 5 and Figure 11 The invention discloses a reinforcement component 300 that helps prevent delamination without violating these design constraints. At least one reinforcement component may be provided along each of the substrates 30, extending from a first end of the balloon 80 (i.e., from the bushing 71) to a second end of the balloon 80 (i.e., to the bushing 88). Thus, in the case where the balloon 80 comprises ten substrates 30, ten reinforcement components 300 may also be provided, one reinforcement component provided on each of the ten substrates. However, more than one reinforcement component 300 may be provided on each substrate 30. The reinforcement component 300 may be attached to the substrate 30 by any suitable method (e.g., with an adhesive).

[0049] Preferably, each reinforcing component 300 may be in the form of a yarn and, when assembled, present a generally rectangular cross-sectional shape with a thickness between about 0.0005 inches and 0.005 inches. The yarn may be made of an ultra-high molecular weight polymer or a liquid crystal polymer, such as VECTRAN manufactured by Kuraray. TMFabrication. As long as the thickness of the yarn is less than the thickness of the electrode 33, it can be disposed on the top surface of the substrate 30, i.e., adjacent to the electrode 33, so that it will not contact the outer surface 26 of the balloon 80. However, if the thickness of the yarn is greater than the thickness of the electrode 33, such that the yarn may hinder the electrode's ability to conform to the patient's tissue, then the yarn should be disposed on the bottom surface of the substrate, so that it will also be disposed directly against the outer surface 26 of the balloon 80. This is Figure 5 and Figure 11 The implementation plan reflected in the document.

[0050] Based on the embodiments shown and described herein, the applicant has designed methods for using the catheter described herein, and variations thereof. In a first variation, the method may include the steps of: allowing flushing fluid to flow through a second lumen and into a balloon, and preventing the flushing fluid from entering the outer tubular shaft via a distal portion of the outer tubular shaft. In a second variation, the method may include preventing air from entering the outer tubular shaft via a proximal portion of the outer tubular shaft. In a third variation, the method may include the steps of: extending the balloon out of the probe, inflating the balloon, collapsing the balloon, withdrawing the balloon back into the probe, and repeating the extension, inflation, collapse, and withdrawal steps five to twenty times. In a fourth variation, the method may include the steps of the first and second variations. In a fifth variation, the method may include the steps of the first and third variations. In a sixth variation, the method may include the steps of the second and third variations. In a seventh variation, the method may include the steps of the first, second, and third variations.

[0051] Any examples or embodiments described herein may also include various other features in addition to or as alternatives to those described above. The teachings, expressions, embodiments, examples, etc., described herein should not be considered independent of each other. Various suitable ways in which the teachings herein can be combined will become apparent to those skilled in the art upon reference to the teachings herein.

[0052] Exemplary embodiments of the subject matter contained herein have been shown and described, and further improvements to the methods and systems described herein can be achieved through appropriate modifications without departing from the scope of the claims. Furthermore, while the methods and steps described above represent specific events occurring in a particular order, it is intended that certain specific steps need not necessarily be performed in the described order, but can be performed in any order, as long as the steps enable the embodiment to achieve its intended purpose. Therefore, if variations of the invention exist and such variations fall within the substantial scope of the disclosure or equivalents of the invention found in the claims, this patent is intended to cover those variations as well. Many such modifications will be apparent to those skilled in the art. For example, the examples, embodiments, geometries, materials, dimensions, ratios, steps, etc., described above are illustrative. Therefore, the claims should not be limited to the specific details of the structures and operations shown in this written description and the accompanying drawings.

Claims

1. A catheter comprising: an outer tubular shaft having an outer surface, a first lumen disposed therethrough, and a second lumen disposed therethrough; an inner tubular shaft having an outer surface disposed in the first lumen of the outer tubular shaft and having a distal portion that extends out of a distal portion of the outer tubular shaft, wherein the inner tubular shaft is movable relative to the outer tubular shaft; a catheter balloon having a membrane comprising a first end and a second end, the first end connected to the outer surface of the outer tubular shaft around a distal portion of the outer tubular shaft and the second end connected to the outer surface of the distal portion of the inner tubular shaft such that a distal section of the inner tubular shaft is disposed in the catheter balloon, the second lumen for introducing a flushing fluid into the catheter balloon; a coupler component attached to the distal portion of the outer tubular shaft at a location distal of the first end of the catheter balloon such that the inner tubular shaft extends into the catheter balloon through the coupler component; and a seal disposed around the distal section of the inner tubular shaft, the seal preventing the flushing fluid from entering a space between the inner tubular shaft and the outer tubular shaft, the seal comprising a distal seal portion and a proximal seal portion, wherein the proximal seal portion cooperates with the coupler component. The seal has a tubular configuration.

2. The catheter of claim 1, wherein, The second lumen terminates at a second lumen opening through the outer surface of the outer tubular shaft, the second lumen opening being in the distal portion of the outer tubular shaft in the balloon.

3. The catheter of claim 1, wherein, The coupler component comprises a sidewall and a window disposed through the sidewall, the window exposing the second lumen opening.

4. The catheter of claim 3, wherein, The distal seal portion comprises a first material and the proximal seal portion comprises a second material.

5. The catheter of claim 3, wherein, The first material comprises barium sulfate.

6. The catheter of claim 5, wherein, The first material comprises 20% barium sulfate.

7. The catheter of claim 6, wherein, The distal seal portion has a pre-assembly wall thickness of between 0.00375 inches and 0.00750 inches.

8. The catheter of claim 3, wherein, The distal seal portion has a pre-assembly wall thickness of 0.00525 inches.

9. The catheter of claim 8, wherein, The distal seal portion has a pre-assembly inner diameter of between 0.055 inches and 0.065 inches.

10. The catheter of claim 8, wherein, The distal seal portion has a pre-assembly inner diameter of 0.061 inches.

11. The catheter of claim 10, wherein, The proximal seal portion has a pre-assembly wall thickness of between 0.003 inches and 0.005 inches.

12. The catheter of claim 10, wherein, The proximal seal portion has a pre-assembly wall thickness of 0.00375 inches.

13. The catheter of claim 12, wherein, The proximal seal portion has a pre-assembly inner diameter of between 0.0064 inches and 0.0068 inches.

14. The catheter of claim 12, wherein, The proximal seal portion has a pre-assembly inner diameter of 0.0655 inches.

15. The catheter of claim 14, wherein, The distal section of the inner tubular shaft has an outer diameter that is greater than or equal to the pre-assembly inner diameter of the distal seal portion.

16. The catheter of claim 14, wherein, The distal section of the inner tubular shaft has an outer diameter that is greater than or equal to the pre-assembly inner diameter of the proximal seal portion.

17. The catheter of claim 16, wherein, The seal is between 10 millimeters long and 25 millimeters long.

18. The catheter of claim 16, wherein, The seal is 23 millimeters long.

19. The catheter of claim 18, wherein, ​ 20. The catheter of claim 17, wherein, The seal is shorter than the distal section of the inner tubular shaft.

21. The catheter of claim 20, wherein, The distal seal portion is between 0.09 inches long and 0.13 inches long.

22. The catheter of claim 21, wherein, The distal seal portion is 0.11 inches long.

23. The catheter of claim 21, wherein, The distal seal portion is disposed in a friction fit relationship around the inner tubular shaft.

24. The catheter of claim 23, wherein, The proximal seal portion is disposed in a friction fit relationship around the inner tubular shaft.

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