Self-forming prosthetic valve annulus apparatus

Abstract

The present invention relates to a self-forming prosthetic valve annulus apparatus, comprising a main body core wire, a proximal release structure, a developing member, and a distal protection member. The main body core wire is formed by processing a metal wire having shape memory characteristics, the overall structure of the main body core wire is spiral spring-shaped, and a portion of the main body core wire close to a distal end expands and extends outward along an Archimedean spiral. The proximal release structure is connected to a proximal end of the main body core wire. The developing member is disposed at the portion of the main body core wire close to the distal end. The distal protection member is disposed at a distal end portion of the main body core wire. The portion of the main body core wire close to the distal end expands and extends outward along the Archimedean spiral, thereby greatly improving its probability of winding the chordae tendineae or valve leaflet, and effectively improving the success rate of the mitral valve replacement surgery. During implantation of the prosthetic valve annulus, the end portion expanding outward along the Archimedean spiral can wind around the outer side of the chordae tendineae or mitral valve leaflet, thereby reducing the difficulty of implanting the prosthetic valve annulus, and thus improving the success rate of the mitral valve replacement surgery.

Description

A self-forming prosthetic annuloplasty device TECHNICAL FIELD

[0001] The present application relates to the technical field of heart valve disease medical devices, in particular to a self-forming prosthetic annuloplasty device. BACKGROUND

[0002] Mitral valve disease is the most common type of heart valve disease. Cardiovascular disease has been the leading cause of death worldwide for a long time. In China, the mortality rate caused by cardiovascular disease has increased by 65% in the past nearly three decades (GBD Compare). Cardiovascular disease includes arteriosclerosis, myocardial infarction, stroke, arrhythmia and valvular disease, etc. Valvular disease, including aortic valve, pulmonary valve, mitral valve and tricuspid valve disease, is one of the important causes of heart failure, stroke and other heart attacks, and mitral valve disease is the most common type of all valvular diseases.

[0003] Mitral valve disease mainly includes mitral regurgitation (MR) and mitral stenosis (MS). Mitral regurgitation refers to the phenomenon that the mitral valve cannot completely close due to abnormalities or functional abnormalities of any structure in the valve leaflet, annulus, chordae, papillary muscle, left ventricle, and blood flows back to the left atrium. Regurgitation leads to increased blood flow and elevated blood pressure in the left atrium, and elevated pulmonary venous blood pressure. Severe cases can cause pulmonary edema, myocardial damage, heart failure and even death. Mitral stenosis refers to the phenomenon that the mitral valve opening is narrow and blood cannot flow from the left atrium to the left ventricle. Insufficient oxygen-rich blood supply leads to fatigue and difficulty breathing. The increased blood in the left atrium leads to elevated left atrial pressure and left atrial enlargement, which can also cause pulmonary edema.

[0004] An aging society will bring a huge patient population. According to a population-based survey by the Mayo Clinic in the United States, the incidence of all types of valvular diseases increases with age, and the incidence of mitral regurgitation is much higher than that of aortic stenosis, aortic regurgitation, mitral stenosis and other diseases. However, considering that about half of MR patients have high surgical risks due to low cardiac function, multiple comorbidities, advanced age and other factors, they do not undergo surgery, so a large number of treatment needs have not been met.

[0005] There are few products for interventional surgery, and a large number of technical problems have not been overcome. Currently, only one product has been approved globally, but the clinical data of this product is still not very ideal, so the penetration rate is much lower than that of TAVR.

[0006] Since the position of the mitral valve is between the left atrium and the left ventricle, and the mitral annulus increases the difficulty of accurate placement of the artificial valve, the current TMVR (transcatheter mitral valve implantation surgery) adopts a transapical approach, and a high-curved delivery catheter is required to reach the autologous mitral valve through the interventricular septum, which has extremely high engineering requirements. Similar to transcatheter aortic valve replacement (TAVR), the completely percutaneous (femoral vein) surgery is the preferred method with less invasiveness for TMVR. However, the challenge faced by this method is how to deliver a large-sized delivery system (to accommodate a large artificial valve) to the mitral valve in a small space (transseptal approach) at an extreme angle (more than 90° bending), therefore, it is necessary to use a pre-implanted artificial annulus structure to fix the implanted artificial valve, and in the prior art, the implantation of the artificial annulus is difficult due to the uneven length of the chordae tendineae, irregular annulus shape, and narrow ventricular space, resulting in a complex and time-consuming mitral valve replacement surgery with low success rate, therefore, it is necessary to optimize the artificial annulus structure of the prior art. SUMMARY

[0007] Based on the above description, the present application provides a self-forming artificial annulus device to solve the technical problems of landing difficulty and low success rate of surgery in the prior art.

[0008] The technical scheme for solving the above technical problems of the present application is as follows:

[0009] A self-forming artificial annulus device, comprising a main body wire, a proximal release structure, a developing member and a distal protection member;

[0010] The main body wire is made of a metal wire with shape memory properties, and the whole main body wire is in a spiral spring structure, and the part near the distal end of the main body wire extends outward along an Archimedes spiral line;

[0011] The proximal release structure is connected to the proximal end of the main body wire;

[0012] The developing member is arranged on the part near the distal end of the main body wire;

[0013] The distal protection member is arranged on the distal end of the main body wire.

[0014] Compared with the prior art, the technical scheme of the present application has the following beneficial technical effects:

[0015] The self-forming artificial valve annulus device provided by the application has a part of the main core wire close to the distal end extending along an Archimedes spiral, greatly improving the probability of winding the chordae tendineae or the valve leaflet, and effectively improving the success rate of mitral valve replacement surgery.

[0016] Based on the above technical solution, the application can be further improved as follows.

[0017] Further, the number of spiral turns of the main core wire is not less than two turns, and the part extending along the Archimedes spiral is 1 / 4 to 1 / 2 turn of the distal end.

[0018] After the above scheme is adopted, the distal end of the main core wire can be wound along the outside of the chordae tendineae or the mitral valve leaflet as much as possible.

[0019] Further, the main core wire comprises a main segment and a distal end grinding segment located at the distal end of the main segment, and the distal end grinding segment is located in the part extending along the Archimedes spiral.

[0020] Further, the outer diameter of the distal end grinding segment smoothly decreases in the direction towards the distal end, so that the distal end grinding segment forms an elongated cone.

[0021] The structure has certain flexibility and self-adaptability, which meets the outside winding while avoiding damage to the inner wall of the ventricle.

[0022] Further, the developing member comprises a developing spring, and the developing spring is made of platinum-tungsten alloy, platinum-iridium alloy or gold wire having developing property under X-ray or ultrasound.

[0023] Further, the developing spring is welded or glued to the main core wire.

[0024] The developing spring is provided without affecting the flexibility of the main core wire itself, which ensures the position confirmation in the artificial valve implantation process and ensures that the artificial valve is implanted into the predetermined position.

[0025] Further, the distal end protection member is woven into a predetermined three-dimensional shape by a metal wire having shape memory property, and the metal wire used for the distal end protection member is thinner than the metal wire used for the main core wire.

[0026] Further, the distal end protection member is in the form of a ball cage or a water drop with a diameter of 2-5 mm.

[0027] The distal protection member has elasticity and shape memory function, which is beneficial to protect the inner wall of the ventricle from damage and does not affect the pushing and recovery of the artificial valve ring device in the matching delivery sheath tube.

[0028] Further, the proximal release structure is configured to be released from the matching delivery member by any one of mechanical release, electrolytic release and hydrolytic release, and the proximal release structure can be completely accommodated in the matching delivery sheath tube by the delivery member before release.

[0029] Further, the proximal release structure includes a ball, and the end of the delivery member is correspondingly provided with a clamping jaw, and the clamping jaw is formed with an arc-shaped groove matched with the ball.

[0030] Further, the proximal release structure includes a tube, and the side wall of the tube is formed with a T-shaped limiting groove, the end of the delivery member is correspondingly provided with a clamping jaw, and the clamping jaw is formed with a T-shaped block matched with the limiting groove.

[0031] Further, the proximal release structure includes a first limiting buckle, one side of the first limiting buckle is formed with a limiting bayonet, and the end of the delivery member is correspondingly provided with a second limiting buckle, and the second limiting buckle is formed with a matching bayonet matched with the limiting bayonet.

[0032] The simple and easy-to-operate release mode facilitates effective release of the artificial valve ring device.

[0033] Further, a surface lubricating layer is further included, and the surface lubricating layer is uniformly covered on the outer surfaces of the main body core wire, the proximal release structure, the developing member and the distal protection member.

[0034] Further, the surface lubricating layer is any one of a medical-grade fluorine-containing material heat-shrinkable tube, a hydrophilic coating and a hydrophobic coating.

[0035] The surface lubricating layer can greatly reduce the resistance to the inner wall of the ventricle during delivery. BRIEF DESCRIPTION OF DRAWINGS

[0036] Fig. 1 is a structural schematic view of a self-forming artificial valve ring device according to an embodiment of the present application;

[0037] Fig. 2 is a top view of the self-forming artificial valve ring device according to the embodiment of the present application;

[0038] Fig. 3 is a schematic view of three release forms of mechanical release according to the embodiment of the present application;

[0039] Fig. 4 is a schematic view of the connection between the self-forming artificial valve ring device according to the embodiment of the present application and an artificial valve;

[0040] Fig. 5 is a schematic view of the state of the self-forming artificial valve ring device implanted in the body according to the embodiment of the present application. DETAILED DESCRIPTION

[0041] For the purposes of this application, reference will be made to the accompanying drawings in which embodiments of the application are illustrated. The application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0043] It will be understood that the spatially relative terms "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can also be oriented in the other direction, and the spatially relative terms used herein are intended to encompass such additional orientations. It is to be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can also be oriented in the other direction, and the spatially relative terms used herein are intended to encompass such additional orientations.

[0044] It is to be noted that when an element is referred to as being "connected" to another element, it can be directly connected to the other element, or connected to the other element with intervening elements. "Connected" in the following embodiments should be understood as "electrically connected", "communicatively connected", etc. if the circuits, modules, units, etc. connected to each other have transmission of electrical signals or data.

[0045] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", or the like, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0046] As shown in FIG. 1 and FIG. 2, the self-forming artificial annulus device 100 according to the embodiments of the present application comprises a main body wire 110, a proximal release structure 120, a radiopaque member 130 and a distal protection member 140.

[0047] Wherein, the self-forming artificial annulus device 100 is entirely accommodated into the delivery sheath tube matched with it before implantation, and is pushed or recovered by a delivery member connected with the proximal end thereof. Generally, the delivery member is a delivery wire with considerable length.

[0048] The main core wire 110 is formed by a metal wire with shape memory property, specifically, by a nickel-titanium wire with shape memory function processed by grinding and heat setting. The whole thereof is in a spiral spring structure, and the spiral angle can be clockwise or counterclockwise. In the embodiment, the structure with counterclockwise spiral angle is described. It should be understood that, due to the symmetry of the mitral valve, the different spiral angles have negligible influence on the implantation of the artificial annulus device except for the adaptation of the direction habit.

[0049] The part of the main core wire 110 near the distal end A extends along an Archimedes spiral. It should be understood that, in the embodiment of the present application, the proximal end and the distal end are according to the general understanding, the proximal end is closer to the operator during the implantation, and the distal end is the end first reaching the predetermined landing position. The Archimedes spiral is a trajectory generated by a point moving away from a fixed point at a constant speed while rotating around the fixed point at a fixed angular velocity, which belongs to an equal speed ratio spiral. Since it extends outward at equal distance in each rotation period, it can also be called an equal distance spiral, which is a basic geometric concept and will not be described here.

[0050] Wherein, the number of spiral turns of the main core wire 110 is not less than two turns, generally 2-8 turns, which can be selected and manufactured according to the actual operation condition, and the part extending along the Archimedes spiral is 1 / 4-1 / 2 turn of the most distal end. The 1 / 4-1 / 2 turn of the most distal end extending along the Archimedes spiral can make the distal end of the main core wire 110 possibly loop around the outside of the chordae tendineae or the mitral valve leaflet.

[0051] Specifically, the main core wire 110 includes a main body segment 111 and a distal grinding segment 112 located at the distal end of the main body segment 111. The distal grinding segment 112 is entirely located in the part extending along the Archimedes spiral of the main core wire 110. Preferably, the outer diameter size of the distal grinding segment 112 smoothly decreases in the direction towards the distal end, so that the distal grinding segment 112 constitutes an elongated cone. The elongated cone-shaped distal grinding structure has certain flexibility and self-adaptability, which can loop around the outside while avoiding damage to the intraventricular wall.

[0052] The proximal release structure 120 is connected to the proximal end of the main body core wire 110; specifically, the proximal release structure 120 is configured to be released from the matched delivery member (i.e. the delivery wire 200) by any one of mechanical release, electrolytic release, and hydrolytic release, and the proximal release structure 120 can be completely accommodated into the matched delivery sheath before being released.

[0053] The present application is described by using three release forms of mechanical release:

[0054] The first release form: as shown in (a) of FIG. 3, the proximal release structure 120 includes a ball 121, and the end of the delivery wire 200 is correspondingly provided with a natural state (i.e. not under the pressure of the outer ring) outwardly opening clamping jaw 210, and the clamping jaw 210 is formed with an arc-shaped groove 211 matched with the ball 120, and when the clamping jaw 210 clamps the ball 121, the arc-shaped groove 211 cooperates with the surface of the ball 121, without excessively increasing the overall matched outer diameter, so as to be conveniently accommodated into the delivery sheath. The release principle is that when the delivery wire 200 is pushed to make the clamping jaw 210 exposed from the distal end of the delivery sheath, the clamping jaw 210 is opened under the action of its own elasticity, so as to realize the release of the artificial valve annulus device 100.

[0055] The second release form: as shown in (b) of FIG. 3, the proximal release structure 120 includes a tube 122, and the side wall of the tube 122 is formed with a T-shaped limiting groove 122a, and the end of the delivery wire 200 is correspondingly provided with a natural state (i.e. not under the pressure of the outer ring) outwardly opening clamping jaw 210, and the clamping jaw 210 is formed with a T-shaped block 212 matched with the limiting groove 122a, and when the clamping jaw 210 clamps the tube 122, the T-shaped block 212 cooperates with the T-shaped limiting groove 122a of the ball, without excessively increasing the overall matched outer diameter, so as to be conveniently accommodated into the delivery sheath, and the release principle is similar to the first release form, which is not described herein.

[0056] The third release form: as shown in (c) of FIG. 3, the proximal release structure 120 includes a first limiting buckle 123, one side of the first limiting buckle 123 is formed with a limiting bayonet 123a, and the end of the delivery wire 200 is correspondingly provided with a second limiting buckle 220, and the second limiting buckle 220 is formed with a matched bayonet 221 matched with the limiting bayonet 123a, and the connection of the first limiting buckle 123 and the second limiting buckle 220 is realized by the clamping limiting of the matched bayonet 221 and the limiting bayonet 123a, and the second limiting buckle 220 is designed to swing away from the matched bayonet 221 in the natural state (i.e. not under the pressure of the outer ring), so as to realize the automatic release as above.

[0057] The developing member 130 is arranged on the part of the main body core wire 110 close to the distal end, wherein the developing member 130 comprises a developing spring 131, the developing spring 131 is made of platinum-tungsten alloy, platinum-iridium alloy or gold wire which has developing property under X-ray or ultrasound, the developing spring 131 is arranged without affecting the flexibility of the main body core wire 110, and the developing spring 131 can be fully developed under X-ray or ultrasound and can be accurately positioned during the implantation of the artificial annuloplasty device 100; the artificial annuloplasty device 100 can be used for mitral valve replacement under ultrasound alone; compared with the existing commercial products, the operation process is simpler and the operation time is obviously shortened because the DSA and ultrasound equipment need to be frequently used alternately during the operation.

[0058] Preferably, the developing spring 131 is welded or glued to the main body core wire 110.

[0059] The distal end protection member 140 is arranged on the distal end of the main body core wire 110.

[0060] The distal end protection member 130 is made of metal wire with shape memory property and is woven into a predetermined three-dimensional shape, wherein the metal wire used for the distal end protection member 130 is thinner than the metal wire used for the main body core wire 110, and specifically, in the embodiment, the distal end protection member 140 is made of extremely thin nickel-titanium wire and platinum-tungsten wire and is mixed and woven, and the whole is heat set to be spherical cage or water drop shape with a diameter of 2-5 mm. The distal end protection member 140 with the above structure has certain elasticity and shape memory function, which is beneficial to protect the inner wall of the ventricle from being damaged and does not affect the pushing and recovery of the artificial annuloplasty device 100 in the delivery sheath tube matched therewith.

[0061] Preferably, the artificial annuloplasty device 100 comprises a surface lubricating layer which is uniformly covered on the outer surface of the main body core wire 110, the proximal end release structure 120, the developing member 130 and the distal end protection member 140. The surface lubricating layer is any one of medical grade fluorine-containing material heat shrink tube, hydrophilic coating and hydrophobic coating, and the surface lubricating layer can greatly reduce the resistance to the inner wall of the ventricle during the delivery process.

[0062] The self-forming artificial annuloplasty device 100 provided in the application is released through the delivery system matched therewith, the cooperation relationship thereof with the artificial valve 300 is shown in Fig. 4, and the cooperation relationship thereof with the native valve leaflet / tendon 400 is shown in Fig. 5, the native valve leaflet / tendon 400 is clamped between the self-forming artificial annuloplasty device 100 and the artificial valve 300, and preferably, in actual operation, the inner diameter of the self-forming artificial annuloplasty device 100 is slightly smaller than the outer diameter of the artificial valve 300, so that the self-forming artificial annuloplasty device 100 can tightly clamp the artificial valve 300, and the risk of paravalvular leakage and left ventricular outflow tract obstruction can be effectively prevented.

[0063] It can be understood that the artificial annulus device 100 provided by the application can also be implanted using the ring shrinking mechanism in mitral valve repair, which will not be repeated here.

[0064] According to the above description, the self-forming artificial annulus device provided by the embodiments of the application has at least the following advantages:

[0065] 1. The artificial annulus structure for mitral valve replacement is designed innovatively, which enhances its stability without causing outflow tract obstruction risk.

[0066] 2. The unique Archimedes spiral expansion structure at the distal end can greatly improve the probability of winding the chordae tendineae or valve leaflets, effectively improving the success rate of mitral valve replacement surgery.

[0067] 3. The distal end protection with flexibility and support can adapt to various narrow and uneven inner surface of the left ventricular space, without damaging the internal tissues of the ventricle during the bypass process, which can greatly reduce the risk of postoperative complications.

[0068] 4. The release action of the artificial annulus device in the application is simple and easy to operate. After the matching delivery system is in place, only the push or withdrawal of the delivery wire action is needed to achieve the winding of the chordae tendineae or valve leaflets and to meet the 96% or more length of the artificial ring recycling. The recycling times are unlimited, which can effectively improve the success rate of surgery.

[0069] 5. The artificial annulus device in the embodiment can be fully visualized under X-ray or ultrasound, and can be accurately positioned. It can realize the mitral valve replacement under ultrasound alone. The few commercial products need to frequently alternate the use of DSA and ultrasound equipment during the operation, which is complex and time-consuming.

[0070] 6. The artificial annulus device has multiple release paths, which can meet the percutaneous and transapical paths at the same time. The percutaneous path can be released through the femoral artery or femoral vein. It breaks through the technical barrier of the current commercial products which mainly use the transapical path.

[0071] 7. The artificial annulus device has low manufacturing and processing cost and high realization rate, which can greatly reduce the product cost.

[0072] 8. The artificial annulus device does not affect the opening and closing of the mitral valve during the release process, which can greatly reduce the heart load and the probability of postoperative complications such as atrial fibrillation.

[0073] 9. The artificial annulus device can tightly wrap the chordae tendineae or valve leaflets with the artificial valve, which is tightly and firmly matched, reliable, and can effectively reduce the risk of paravalvular leakage and outflow tract obstruction.

[0074] The above merely describes preferred embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A self-forming artificial valve annulus device, characterized in that, Includes the main core wire, proximal release structure, developing element, and distal protection element; The main core wire is formed by processing metal wire with shape memory properties. The main core wire has a spiral spring-like structure. The part of the main core wire near the far end extends outward along the Archimedean spiral. The proximal release structure is connected to the proximal end of the main core wire; The developing element is disposed on the portion of the main core wire near the distal end; The distal protective element is disposed at the distal end of the main core wire.

2. The self-forming artificial valve annulus device according to claim 1, characterized in that, The main core wire has no less than two spiral turns, and the portion extending outward along the Archimedean spiral is 1 / 4 to 1 / 2 of the furthest turn.

3. The self-forming artificial valve annulus device according to claim 1, characterized in that, The main core wire includes a main body segment and a distal grinding segment located within the main body segment. The distal grinding segment is entirely located in the portion of the main core wire that extends outward along the Archimedean spiral.

4. The self-forming artificial valve annulus device according to claim 3, characterized in that, The outer diameter of the distal grinding section decreases smoothly in the direction toward the distal end, making the distal grinding section a slender cone shape.

5. The self-forming artificial valve annulus device according to any one of claims 1-4, characterized in that, The developing element includes a developing spring, which is made of platinum-tungsten alloy, platinum-iridium alloy or gold wire that is radiolucent under X-ray or ultrasound.

6. The self-forming artificial valve annulus device according to claim 4, characterized in that, The developing spring is attached to the main core wire by welding or gluing.

7. The self-forming artificial valve annulus device according to any one of claims 1-4, characterized in that, The remote protective component is woven from metal wires with shape memory properties into a predetermined three-dimensional shape, and the metal wires used in the remote protective component are thinner than the metal wires used in the main core wire.

8. The self-forming artificial valve annulus device according to claim 7, characterized in that, The distal protective component is a spherical or teardrop-shaped structure with a diameter of 2-5 mm.

9. The self-forming artificial valve annulus device according to any one of claims 1-4, characterized in that, The proximal release structure is configured to release itself from the compatible conveyor via any one of mechanical release, electrical release, or water release, and the proximal release structure can be completely contained into the matching conveyor sheath by the conveyor before it is released.

10. The self-forming artificial valve annulus device according to claim 9, characterized in that, The proximal release structure includes a sphere, and the end of the conveyor is provided with a gripper, on which an arc-shaped groove adapted to the sphere is formed.

11. The self-forming artificial valve annulus device according to claim 9, characterized in that, The proximal release structure includes a tube body, the sidewall of which is formed with a T-shaped limiting groove, and the end of the conveying component is provided with a gripper, on which a T-shaped block adapted to the limiting groove is formed.

12. The self-forming artificial valve annulus device according to claim 9, characterized in that, The proximal release structure includes a first limiting buckle, with a limiting slot formed on one side of the first limiting buckle, and a second limiting buckle correspondingly provided at the end of the conveying member, with a mating slot formed on the second limiting buckle that is adapted to the limiting slot.

13. The self-forming artificial valve annulus device according to claim 1, characterized in that, It also includes a surface lubricating layer, which uniformly covers the outer surfaces of the main core wire, the proximal release structure, the developing element, and the distal protection element.

14. The self-forming artificial valve annulus device according to claim 13, characterized in that, The surface lubricating layer is any one of medical-grade fluorine-containing heat shrink tubing, hydrophilic coating, or hydrophobic coating.

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