Variable compliance sheath and delivery system

Abstract

The present application relates to a variable compliance sheath and delivery system, the variable compliance sheath comprising: a polymer tube and a reinforcing tube arranged in the polymer tube, at least one temperature regulating tube; the compliance of the reinforcing tube changes with temperature; the temperature regulating tube is in contact with the reinforcing tube for heat exchange with the reinforcing tube; the temperature regulating tube is provided with a circulating lumen penetrating through the temperature regulating tube, the circulating lumen has an inlet and an outlet. Different temperature liquids are injected into the circulating lumen, so that the compliance of the reinforcing tube changes to smoothly pass through blood vessels in different parts.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a variable compliance sheath and delivery system. Background Technology

[0002] Current interventional procedures typically involve first introducing a guidewire along a peripheral blood vessel, followed by the introduction of a delivery sheath along the guidewire to establish an interventional pathway. Once the distal end of the delivery sheath reaches the treatment site, the guidewire is withdrawn, and the implant is introduced along the interventional pathway within the delivery sheath to the treatment site. After the implant is released, the delivery sheath is withdrawn to complete the interventional procedure. The delivery sheath often needs to traverse relatively long blood vessels to reach the treatment site, passing through multiple locations with varying degrees of vascular curvature. Greater vascular curvature requires a more flexible sheath for successful passage, but an overly flexible sheath offers less support, hindering its advancement within the vessel. Currently, once manufactured, the sheath exhibits a single type of flexibility, suitable only for certain types of vascular structures. In complex interventional settings, delivery is challenging, requiring extensive experience from the surgeon to successfully reach the treatment site. Summary of the Invention

[0003] Based on the above situation, it is necessary to provide a delivery sheath with adjustable flexibility in real time to solve the problem of difficult sheath delivery in complex interventional procedures.

[0004] This invention provides a variable compliance sheath, comprising: a polymer tube and a reinforcing tube disposed in the wall of the polymer tube, and at least one temperature-regulating tube;

[0005] The temperature-regulating tube contacts the reinforcing tube for heat exchange, thereby causing the flexibility of the reinforcing tube to change with temperature. The temperature-regulating tube has a circulation cavity with an inlet and an outlet, both located near the proximal end of the variable flexibility sheath.

[0006] In one embodiment, the temperature control tube includes an inflow section and an outflow section, as well as a connecting section connecting the inflow section and the outflow section;

[0007] The inflow section and the outflow section extend along the length of the temperature regulating tube. The inlet is located at the proximal end of the inflow section, and the outlet is located at the proximal end of the outflow section. The connecting section connects the inflow section and the outflow section.

[0008] In one embodiment, the inflow section includes an inflow spiral structure, and the outflow section includes an outflow spiral structure; the pitch of the inflow spiral structure and the pitch of the outflow spiral structure are equal, and the spiral coils of the inflow spiral structure and the spiral coils of the outflow spiral structure are arranged alternately.

[0009] In one embodiment, the reinforcing tube includes a supporting spiral structure, the pitch of which is equal to the pitch of the inflow spiral structure, and a spiral coil of the inflow spiral structure and a spiral coil of the outflow spiral structure are provided between each two adjacent spiral coils of the supporting spiral structure.

[0010] In one embodiment, the temperature regulating tube includes a first tube segment and a second tube segment connected along its length, the second tube segment being located at the distal end of the first tube segment, and the volume of the circulation cavity per unit length in the second tube segment being greater than the volume of the circulation cavity per unit length in the first tube segment.

[0011] In one embodiment, the first pipe segment includes a first helical structure, the second pipe segment includes a second helical structure, and the density of the first helical structure is less than the density of the second helical structure.

[0012] In one embodiment, the first pipe segment includes a hollow inlet section and an outlet section that are separated from each other and extend along the length of the temperature-regulating pipe, wherein the inlet is located at the proximal end of the inlet section and the outlet is located at the proximal end of the outlet section.

[0013] The second pipe section includes a cylindrical connecting section, which is coaxially arranged with the reinforcing pipe. The connecting section includes an inner wall surface and an outer wall surface, which define a closed cavity. Two through holes are opened at the proximal end of the connecting section. The distal ends of the inflow section and the distal ends of the outflow section are respectively connected to the two through holes, so that the cavity communicates with the inflow section and the outflow section.

[0014] In one embodiment, the reinforcing tube is provided with a plurality of grooves, which are used to prevent the temperature regulating tube from being exposed; the plurality of grooves are recessed outward from the inner wall surface of the reinforcing tube along the radial direction of the reinforcing tube, or the plurality of grooves are recessed inward from the outer wall surface of the reinforcing tube along the radial direction of the reinforcing tube.

[0015] This application also provides another type of variable compliance sheath, which includes a polymer tube and a circulation lumen and a reinforcing tube disposed in the wall of the polymer tube;

[0016] The circulation lumen has an inlet and an outlet, both located near the proximal end of the sheath; the circulation lumen is used to introduce liquid, thereby causing the flexibility of the reinforcing tube to change with the temperature of the introduced liquid.

[0017] This application also provides a delivery device comprising any of the above-described variable compliance sheaths. The delivery device further comprises an inlet pipe, an outlet pipe, and a temperature regulating device. The inlet pipe connects the inlet on the variable compliance sheath to the temperature regulating device and is used to introduce liquid with a temperature regulated by the temperature regulating device into the circulation cavity. The outlet pipe connects to the outlet on the variable compliance sheath and is used to discharge liquid from the circulation cavity.

[0018] The present invention also provides a delivery system comprising an implant and the aforementioned variable compliance sheath, the implant being delivered to a desired location via the variable compliance sheath.

[0019] In the above technical solution, the circulating lumen of the temperature-regulating tube is used to transport liquids of different temperatures. The liquid flows in from the inlet, passes through the entire circulating lumen, and flows out from the outlet. Because the reinforcing tube is in contact with the temperature-regulating tube, the liquid inside the reinforcing tube undergoes heat exchange, causing its temperature to change, and consequently, the flexibility of the reinforcing tube changes accordingly. Therefore, when passing through blood vessels in different parts of the human body, the operator can inject liquids of different temperatures into the circulating lumen according to the curvature of the blood vessels, changing the flexibility of the reinforcing tube to allow it to pass smoothly through blood vessels in different locations. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the variable compliance sheath of Embodiment 1 of the present invention.

[0021] Figure 2 This is a schematic diagram of the variable compliance sheath of Embodiment 1 of the present invention (a portion of the outer tube has been removed).

[0022] Figure 3 This is a schematic diagram of the structure of the variable compliance sheath of Embodiment 1 of the present invention (the outer tube is hidden).

[0023] Figure 4a This is a schematic diagram of the annular wave ring structure of the reinforcing tube in Embodiment 1 of the present invention.

[0024] Figure 4b This is a schematic diagram of the annular wave coil with the reinforcing tube disposed inside the temperature regulating tube according to the present invention.

[0025] Figure 5a This is a schematic diagram of one structure of the temperature control tube in Embodiment 1 of the present invention.

[0026] Figure 5b This is a schematic diagram of another structure of the temperature control tube in Embodiment 1 of the present invention.

[0027] Figure 6This is a schematic diagram of the variable compliance sheath of Embodiment 2 of the present invention (a portion of the outer tube has been removed).

[0028] Figure 7 This is a schematic diagram of the variable compliance sheath of Embodiment 2 of the present invention (the outer tube is hidden).

[0029] Figure 8 This is a schematic diagram of the variable compliance sheath of Embodiment 3 of the present invention (a portion of the outer tube has been removed).

[0030] Figure 9 This is a schematic diagram of the temperature control tube in Embodiment 3 of the present invention.

[0031] Figure 10 This is a schematic diagram of the temperature control tube in Embodiment 4 of the present invention.

[0032] Figure 11 for Figure 10 Cross-sectional view at point A.

[0033] Figure 12 This is a schematic diagram of the variable compliance sheath of Embodiment 5 of the present invention.

[0034] Figure 13 for Figure 12 Enlarged view of point A in the middle. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0036] 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 invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] To more clearly describe the structure of the variable compliance sheath, the terms "distal" and "proximal" are used here, which are conventional terms in the field of interventional medical devices. Specifically, "distal" refers to the end furthest from the operator during the procedure, and "proximal" refers to the end closest to the operator during the procedure.

[0038] Example 1

[0039] like Figure 1 and Figure 2As shown, this embodiment provides a variable flexibility sheath 1, which includes a polymer tube 11, a reinforcing tube 12 disposed within the polymer tube 11, and at least one temperature-regulating tube 13; the flexibility of the reinforcing tube 12 changes with temperature; the temperature-regulating tube 13 contacts the reinforcing tube 12 for heat exchange; a circulation cavity (not shown in the figure) is provided inside the temperature-regulating tube 13, such as... Figure 5a As shown, the circulation cavity has an inlet 131 and an outlet 132.

[0040] In this embodiment, the reinforcing tube 12 is made of shape memory alloy, such as nickel-titanium alloy or nickel-cobalt alloy. Shape memory alloy has a shape memory effect, which can achieve the effect of easy deformation at low temperature and self-recovery at body temperature.

[0041] The polymer tube 11 includes an inner tube 111 and an outer tube 112, with the temperature-regulating tube 13 and the reinforcing tube 12 disposed between the inner tube 111 and the outer tube 112. The inner tube 111 is a lubricating layer, and its material can be PTFE (polytetrafluoroethylene). The inner tube 111 forms a delivery channel. The reinforcing tube 12 and the temperature-regulating tube 13 are disposed outside the inner tube 111, and the outer tube 112 wraps around the reinforcing tube 12, the temperature-regulating tube 13, and the inner tube 111.

[0042] The outer tube 112 has good biocompatibility, and its material can be a polymer material such as elastic nylon, polyethylene or thermoplastic polyurethane.

[0043] In the above technical solution, the circulation lumen of the temperature-regulating tube 13 is used to transport liquids (inlet water, physiological saline, or other biocompatible liquids) at different temperatures. The liquid flows in from the inlet 131, passes through the entire circulation lumen, and flows out from the outlet 132. When the reinforcing tube 12 comes into contact with the temperature-regulating tube 13, the liquid in the reinforcing tube 12 undergoes heat exchange, causing its temperature to change, and consequently, the flexibility of the reinforcing tube 12 changes accordingly. For example, when passing through blood vessels with a high degree of curvature, a lower temperature liquid is introduced into the circulation lumen, making the reinforcing tube 12 more easily deformable at a low temperature, thereby increasing the overall flexibility of the variable flexibility sheath 1 and making it easier to bend; when passing through blood vessels with a lower degree of curvature, a higher temperature liquid (but not higher than human body temperature) is introduced into the circulation lumen, increasing the resilience of the reinforcing tube 12, reducing its flexibility, increasing the overall rigidity of the variable flexibility sheath 1, and accelerating the advancement speed of the variable flexibility sheath 1.

[0044] Therefore, when passing through blood vessels in different parts of the human body, the operator can inject liquids of different temperatures into the circulation lumen according to the curvature of the blood vessels, thereby changing the flexibility of the reinforcing tube 12 and allowing it to pass smoothly through blood vessels in different parts. Understandably, in actual use, it is necessary to use external temperature control equipment to cool or heat the liquid flowing into the temperature-controlled tube 13.

[0045] In this embodiment, as Figure 3 and Figure 4a , Figure 4b As shown, the reinforcing tube 12 includes a plurality of annular corrugated coils 121 spaced apart along the axial direction of the variable compliance sheath 1. Each annular corrugated coil 121 includes a plurality of adjacently arranged crests 1211 and troughs 1212, which are connected by a connecting rod 1213. The inner wall of the annular corrugated coil 121 is provided with a plurality of grooves 1214 for preventing the temperature regulating tube 13 from opening. These grooves 1214 are recessed outward from the inner wall surface of the annular corrugated coil 121 along the radial direction of the annular corrugated coil 121, with a depth less than the diameter of the connecting rod 1213, thereby preventing the annular corrugated coil 121 from breaking and affecting the strength of the reinforcing tube 12. Figure 4b As shown, when the reinforcing tube 12 is disposed inside the temperature regulating tube 13, the groove is disposed on the outer wall surface of the annular wave coil 121 to prevent the temperature regulating tube from being exposed. The groove 1214 is disposed at the intersection of the temperature regulating tube 13 and the reinforcing tube 12. The temperature regulating tube 13 is disposed within the groove 1214, which avoids excessive local wall thickness of the variable flexible sheath 1 and increases the contact area between the temperature regulating tube 13 and the reinforcing tube 12, thereby improving the heat conduction efficiency. In other embodiments, the reinforcing tube 12 can be a spring tube, a braided mesh tube, a laser-cut perforated mesh tube, etc.

[0046] It is understood that the temperature-regulating tube 13 is made of a flexible material, such as PTFE, PI, or other polymer materials, and its wall thickness should be as thin as possible to avoid affecting the bending performance of the variable flexibility sheath 1. Simultaneously, the smaller the wall thickness of the temperature-regulating tube 13, the higher the heat transfer efficiency between the temperature-regulating tube 13 and the reinforcing tube 12. Therefore, while ensuring that the temperature-regulating tube 13 is not easily damaged during bending, its wall thickness should be minimized. The wall thickness of the temperature-regulating tube 13 ranges from 0.001mm to 0.06mm, and the specific thickness needs to be selected based on the properties of the materials used to ensure that the temperature-regulating tube 13 is not easily damaged. In this embodiment, the temperature-regulating tube 13 is made of PTFE material. In this embodiment, the reinforcing tube 12 is sleeved outside the temperature-regulating tube 13, that is, the temperature-regulating tube 13 is in contact with the inner wall of the reinforcing tube 12. For a very thin temperature-regulating tube 13, during the heat-setting process of the variable flexibility sheath 1, a soft, smooth metal wire needs to be threaded inside the temperature-regulating tube 13 to assist in the forming of the circulating cavity. After the heat-setting process is completed, the metal wire is then removed. In other embodiments, the temperature-regulating tube can be disposed outside the reinforcing tube and in contact with the outer wall of the reinforcing tube.

[0047] In this embodiment, as Figure 5a and Figure 5b As shown, the temperature regulating tube 13 includes an inflow section 133, an outflow section 134, and a connecting section 135 connecting the inflow section 133 and the outflow section 134. The inflow section 133 and the outflow section 134 extend along the length of the temperature regulating tube 13. The inlet 131 is located at the proximal end of the inflow section 133, and the outlet 132 is located at the proximal end of the outflow section 134. The connecting section 135 connects the inflow section 133 and the outflow section 134. The cryogenic liquid enters the temperature regulating tube 13 from the inlet 131 located at the proximal end, flows through the inflow section 133, the connecting section 135, and the outflow section 134, and then flows out from the outlet 132 located at the proximal end. The connecting section 135 can be of any shape, as long as it enables communication between the outflow section 134 and the inflow section 133.

[0048] In this embodiment, to ensure uniform heating of the reinforcing tube 12, such as... Figure 5a As shown, both the inflow section 133 and the outflow section 134 extend first to the distal end of the reinforcing tube 12, and then turn back to the proximal end of the reinforcing tube 12. The connecting section 135 is disposed at the proximal end of the reinforcing tube 12. Similarly, as... Figure 5bAs shown, the variable compliance sheath 1 includes two temperature-regulating tubes 13, which are symmetrically arranged about the central axis of the variable compliance sheath 1. The two outflow sections 134 and the two inflow sections 133 are evenly distributed along the variable compliance sheath 1, thereby ensuring that the heat exchange rates of each part of the reinforcing tube 12 are similar, and quickly adjusting the overall resilience of the variable compliance sheath 1. In other embodiments, the temperature-regulating tube is only located on one side of the variable compliance sheath. When a cryogenic liquid is injected into the temperature-regulating tube, the variable compliance sheath 1 is more likely to bend towards the side where the temperature-regulating tube is located, allowing the variable compliance sheath 1 to better adapt to the shape of curved blood vessels such as the aorta.

[0049] In other embodiments, the variable compliance sheath 1 may include one or more temperature-regulating tubes. Similarly, the inflow and outflow sections of the one or more temperature-regulating tubes may be spaced apart or located close to each other.

[0050] This embodiment also provides a stent system, including an implant (not shown) and the aforementioned variable compliance sheath 1, through which the implant is delivered to the intended location. The implant includes, but is not limited to, medical devices such as vascular stents, occluders, and filters.

[0051] Example 2

[0052] like Figure 6 and Figure 7 As shown, this embodiment provides a variable flexibility sheath 2, which includes a polymer tube 21, a reinforcing tube 22 disposed in the polymer tube 21, and at least one temperature-regulating tube 23; the flexibility of the reinforcing tube 22 changes with temperature; the temperature-regulating tube 23 is in contact with the reinforcing tube 22 for heat exchange; a circulation cavity penetrating the temperature-regulating tube 22 is provided inside the temperature-regulating tube 23, and the circulation cavity has an inlet 231 and an outlet 232.

[0053] The structure and materials of the polymer tube 21 are the same as those of the polymer tube 11 in Example 1, and it also includes an inner tube 211 and an outer tube 212. The reinforcing tube 22 is made of the same material as the reinforcing tube 12 in Example 1, and has lower resilience at low temperatures, i.e., higher flexibility. Under the same external force, the reinforcing tube 22 at lower temperatures is more likely to bend and deform than the reinforcing tube 22 at higher temperatures. The materials of the temperature-regulating tube 23 are the same as those of the temperature-regulating tube 13 in Example 1, and will not be described again here.

[0054] The main difference between the variable compliance sheath 2 in this embodiment and the variable compliance sheath 1 in Embodiment 1 is that the inflow section 233 includes an inflow spiral structure 2331, and the outflow section 234 includes an outflow spiral structure 2341. The pitch of the inflow spiral structure 2331 and the pitch of the outflow spiral structure 2341 are equal, and the spiral coils of the inflow spiral structure 2331 and the spiral coils of the outflow spiral structure 2341 are arranged alternately. The distal ends of the inflow spiral structure 2331 and the distal ends of the outflow spiral structure 2341 are connected by a connecting section 235. Compared with the straight inflow and outflow sections, the inflow section 233 and the outflow section 234, which extend spirally along the axial direction of the variable compliance sheath 2, increase the contact area between the temperature regulating tube 23 and the reinforcing tube 22, thereby improving the heat transfer efficiency. The alternating arrangement of the spiral coils of the inflow spiral structure 2331 and the spiral coils of the outflow spiral structure 2341 can prevent the inflow section 233 and the outflow section 234 from overlapping, thereby avoiding increasing the wall thickness of the variable compliance sheath 2.

[0055] In this embodiment, the reinforcing tube 22 includes a supporting spiral structure 221. The pitch of the supporting spiral structure 221 is equal to the pitch of the inflow spiral structure 2331 and the outflow spiral structure 2341. Between each two adjacent spiral coils of the supporting spiral structure 221, there is one spiral coil of the inflow spiral structure 2331 and one spiral coil of the outflow spiral structure 2341. Further, the shortest distance between two adjacent spiral coils of the supporting spiral structure 221 is equal to the sum of the diameters of the inflow section 233 and the outflow section 234, so that the inflow section 233 and the outflow section 234 are positioned precisely between two adjacent spiral coils of the supporting spiral structure 221. This ensures that both the inflow section 233 and the outflow section 234 are in direct contact with the reinforcing tube 22, improving heat transfer efficiency.

[0056] It is understood that the technical solutions listed in this embodiment are only preferred implementations and do not mean that other technical solutions that can achieve the same basic function are excluded. For example, in other embodiments, the inflow section includes an inflow spiral structure, while the outflow section is a straight structure or other shapes, and the reinforcing tube includes multiple axially arranged annular corrugations. As long as liquid can flow in the inflow section and the outflow section, and the liquid can exchange heat with the reinforcing tube, it is acceptable.

[0057] Example 3

[0058] like Figure 8 and Figure 9As shown, this embodiment provides a variable flexibility sheath 3, which includes a polymer tube 31, a reinforcing tube 32 disposed in the polymer tube 31, and at least one temperature-regulating tube 33; the flexibility of the reinforcing tube 32 changes with temperature; the temperature-regulating tube 33 is in contact with the reinforcing tube 32 for heat exchange; a circulation cavity penetrating the temperature-regulating tube 33 is provided inside the temperature-regulating tube 33, and the circulation cavity has an inlet 331 and an outlet 332.

[0059] The structure and materials of the polymer tube 31 are the same as those of the polymer tube 11 in Example 1, and it also includes an inner tube 311 and an outer tube 312. The materials of the reinforcing tube 32 are the same as those of the reinforcing tube 12 in Example 1. It has lower resilience at low temperatures, that is, higher flexibility. Under the same external force, the reinforcing tube 32 at lower temperatures is more likely to bend and deform than the reinforcing tube 32 at higher temperatures. The materials of the temperature-regulating tube 33 are the same as those of the temperature-regulating tube 13 in Example 1, and will not be described again here.

[0060] The main difference between the variable compliance sheath 3 in this embodiment and the variable compliance sheath 1 in Embodiment 1 is that the temperature-regulating tube 33 includes a first tube segment 335 and a second tube segment 336 connected along its length. The second tube segment 336 is located at the distal end of the first tube segment 335, and the volume of the circulation lumen per unit length in the second tube segment 336 is greater than the volume of the circulation lumen per unit length in the first tube segment 335. In practical use, the distal end of the variable compliance sheath 3 first passes through tortuous blood vessels. Therefore, rapidly increasing the compliance of the distal end of the variable compliance sheath 3 facilitates its smooth passage through tortuous blood vessels. When a cryogenic liquid is introduced, the distal end of the variable compliance sheath 3 contains the most cryogenic liquid per unit length, which can quickly cool the reinforcing tube, making the distal end of the variable compliance sheath 3 easier to bend. Compared to the distal end of the variable flexibility sheath 3, the proximal end of the variable flexibility sheath 3 has less cryogenic fluid content and greater rigidity, providing sufficient support to propel the variable flexibility sheath 3 forward within the tortuous blood vessel.

[0061] Specifically, in this embodiment, the first pipe segment 335 includes a first helical structure 3351, and the second pipe segment 336 includes a second helical structure 3361. The density of the first helical structure 3351 is less than that of the second helical structure 3361, specifically, the pitch of the first helical structure 3351 is greater than that of the second helical structure 3361. To avoid overlap between the inflow segment 333 and the outflow segment 334, the pitches of the inflow segment 333 and the outflow segment 334 change synchronously, and the distance between the inflow segment 333 and the outflow segment 334 along the axial direction of the variable compliance sheath 3 remains constant.

[0062] Example 4

[0063] like Figure 10 As shown, this embodiment provides a variable compliance sheath, which differs from the variable compliance sheath in Embodiment 3 mainly in that the structures of the first tube segment 435 and the second tube segment 436 in this embodiment are different from those in Embodiment 3. The first tube segment 435 includes a hollow inlet section 433 and an outlet section 434 that are separated from each other and extend along the length of the temperature-regulating tube 43. The inlet 431 is located at the proximal end of the inlet section 433, and the outlet 432 is located at the proximal end of the outlet section 434.

[0064] like Figure 11 As shown, the second tube segment 435 includes a cylindrical connecting segment 437, which is coaxially arranged with the reinforcing tube. The connecting segment 437 includes an inner wall surface 4371 and an outer wall surface 4372, defining a closed cavity 4373 between the inner wall surface 4371 and the outer wall surface 4372. Two through holes 4374 are formed at the proximal end of the connecting segment 437. The distal ends of the inflow segment 433 and the outflow segment 434 are respectively connected to the two through holes, so that the cavity 4373 communicates with the inflow segment 433 and the outflow segment 434. The wall thickness of the connecting segment 437 is between 0.001 mm and 0.06 mm, which is sufficiently thin. Therefore, although the connecting segment 437 is cylindrical, it does not affect the flexibility of the variable compliance sheath.

[0065] In this embodiment, the reinforcing tube is sleeved outside the temperature-regulating tube 43. Regardless of whether the reinforcing tube is sleeved outside or inside the temperature-regulating tube 43, at the distal end of the variable compliance sheath, the reinforcing tube and temperature-regulating tube 43 are circumferentially aligned, with a contact area much larger than that of the reinforcing tube and temperature-regulating tube 43 located at the proximal end of the variable compliance sheath. In practical use, the distal end of the variable compliance sheath first passes through tortuous blood vessels; therefore, rapidly increasing the flexibility of the distal end of the variable compliance sheath facilitates its smooth passage through tortuous blood vessels. When cryogenic fluid is introduced, the distal end of the variable compliance sheath contains the most cryogenic fluid per unit length, which rapidly cools the reinforcing tube, making the distal end of the variable compliance sheath easier to bend. Compared to the distal end of the variable compliance sheath, the proximal end contains less cryogenic fluid, resulting in greater rigidity and sufficient support to propel the variable compliance sheath forward within tortuous blood vessels.

[0066] Example 5

[0067] This embodiment provides a variable compliance sheath 5, such as Figure 12 and Figure 13 As shown, it includes a polymer tube 51, a reinforcing tube 52 disposed in the wall of the polymer tube, and a circulation cavity 53;

[0068] The circulation lumen 53 has an inlet 531 and an outlet 532, both of which are located near the proximal end of the variable compliance sheath 5. The circulation lumen 53 is used to introduce liquid, thereby causing the compliance of the reinforcing tube 52 to change with the temperature of the introduced liquid.

[0069] In this embodiment, the reinforcing tube 52 is made of shape memory alloy, such as nickel-titanium alloy or nickel-cobalt alloy. Shape memory alloy has a shape memory effect, which enables it to deform easily at low temperatures and recover itself at body temperature.

[0070] The polymer tube 51 includes an inner tube 511 and an outer tube 512, with a reinforcing tube 52 disposed between the inner tube 511 and the outer tube 512. The inner tube 511 is a lubricating layer, and its material can be PTFE (polytetrafluoroethylene). The inner tube 511 forms a delivery channel, and the reinforcing tube 52 is disposed on the outside of the inner tube 511. The outer tube 512 wraps around the reinforcing tube 52 and the inner tube 511.

[0071] Specifically, when manufacturing the variable flexibility sheath 5, the inner tube 511, reinforcing tube 52, and outer tube 512 are typically fitted together from the inside out. The variable flexibility sheath 5 is then heat-set to bond the inner tube 511 and outer tube 512, with the reinforcing tube 52 encased between them. Therefore, to obtain the aforementioned circulation cavity 53, before the heat-setting process of the variable flexibility sheath 1, a smooth and flexible metal wire with a specific shape is placed between the inner tube 511 and outer tube 512 along with the reinforcing tube 52 to assist in the formation of the circulation cavity 53. After the heat-setting process is completed, the metal wire is then removed.

[0072] In this embodiment, the variable compliance sheath 5 directly utilizes the space between the inner tube 511 and the outer tube 512 of the polymer tube 51 to form a circulation lumen 53 with a certain shape. Compared with adding a temperature-regulating tube, the variable compliance sheath 5 in this embodiment does not affect its own compliance. Furthermore, after introducing liquids of different temperatures into the circulation lumen 53, the resilience of the reinforcing tube 52 can be adjusted, causing the compliance of the reinforcing tube 52 to change, thereby enabling the variable compliance sheath 5 to pass smoothly through blood vessels in different locations.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A variable compliance sheath, characterized in that, include: A polymer tube and a reinforcing tube disposed in the wall of the polymer tube, and at least one temperature-regulating tube; The temperature-regulating tube contacts the reinforcing tube and is used for heat exchange with the reinforcing tube, so that the flexibility of the reinforcing tube changes with temperature. The temperature-regulating tube is provided with a circulation cavity, which has an inlet and an outlet. Both the inlet and the outlet are located at the proximal end of the variable flexibility sheath. The temperature-regulating tube includes a first tube segment and a second tube segment connected along its length. The second tube segment is located at the distal end of the first tube segment. The first tube segment includes a hollow inlet section and an outlet section that are separated from each other and extend along the length of the temperature-regulating tube. The inlet is located at the proximal end of the inlet section, and the outlet is located at the proximal end of the outlet section. The second tube segment includes a cylindrical connecting section that is coaxially arranged with the reinforcing tube. The connecting section includes an inner wall surface and an outer wall surface that define a closed cavity. Two through holes are opened at the proximal end of the connecting section. The distal ends of the inlet section and the outlet section are respectively connected to the two through holes so that the cavity communicates with the inlet section and the outlet section.

2. The variable compliance sheath according to claim 1, characterized in that, The temperature control tube includes an inflow section, an outflow section, and a connecting section connecting the inflow section and the outflow section; The inflow section and the outflow section extend along the length of the temperature regulating tube. The inlet is located at the proximal end of the inflow section, and the outlet is located at the proximal end of the outflow section. The connecting section connects the inflow section and the outflow section.

3. The variable compliance sheath according to claim 2, characterized in that, The inflow section includes an inflow spiral structure, and the outflow section includes an outflow spiral structure; the pitch of the inflow spiral structure and the pitch of the outflow spiral structure are equal, and the spiral coils of the inflow spiral structure and the spiral coils of the outflow spiral structure are arranged alternately.

4. The variable compliance sheath according to claim 3, characterized in that, The reinforcing tube includes a supporting spiral structure, the pitch of which is equal to the pitch of the inflow spiral structure, and a spiral ring of the inflow spiral structure and a spiral ring of the outflow spiral structure are provided between each two adjacent spiral rings of the supporting spiral structure.

5. The variable compliance sheath according to claim 1, characterized in that, The volume of the circulation cavity per unit length in the second pipe section is greater than the volume of the circulation cavity per unit length in the first pipe section.

6. The variable compliance sheath according to claim 5, characterized in that, The first pipe segment includes a first spiral structure, and the second pipe segment includes a second spiral structure. The density of the first spiral structure is less than that of the second spiral structure.

7. The variable compliance sheath according to claim 1, characterized in that, The reinforcing tube is provided with a plurality of grooves, which are used to prevent the temperature regulating tube from being exposed; the plurality of grooves are recessed outward from the inner wall surface of the reinforcing tube along the radial direction of the reinforcing tube, or the plurality of grooves are recessed inward from the outer wall surface of the reinforcing tube along the radial direction of the reinforcing tube.

8. A conveying system, characterized in that, The device includes an implant and a variable compliance sheath as described in any one of claims 1-7, the implant being delivered to a desired location via the variable compliance sheath.

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