Multi-layer conveying sheathing canal and bending-adjustable conveyor system

Abstract

The utility model relates to a multi-layer conveying sheath tube and an adjustable bending conveyor system, the multi-layer conveying sheath tube comprises a tube main body, the tube main body extends along a central axis, the tube main body is provided with an inner layer, a reinforcing layer and an outer layer from inside to outside in sequence, and the inner layer, the reinforcing layer and the outer layer are mutually bonded; the head end is arranged in a conical shape, the outer diameter of the head end is gradually reduced from the near end to the far end, the head end is fixedly connected to the end portion of the far end of the tube body, and the head end and the tube body are mutually fixed in a split splicing mode. The conveying sheathing canal has good skin entering performance and conveying performance in blood vessels, and damage to the blood vessels is small.

Description

Technical Field

[0001] This utility model relates to the field of medical devices, and in particular to a multi-layer delivery sheath and an adjustable bendable delivery system. Background Technology

[0002] Delivery sheaths play a crucial role in the medical field, especially in interventional procedures. Interventional devices all require corresponding sheaths for delivery, and the delivery sheath is an essential component for delivering these devices. It is suitable for delivering interventional medical devices such as occluders, balloon catheters, angiography catheters, vascular stents, and inferior vena cava filters. Current delivery sheaths generally consist of a main tube and a distal tip (TIP). During the procedure, a puncture site is made in the blood vessel, and the tip of the delivery sheath is inserted through this puncture site to deliver the sheath into the blood vessel.

[0003] Existing tip designs typically employ an integral molding process with the main tube, resulting in a multi-layered tip structure. This multi-layered tip structure leads to poor skin penetration and is prone to damaging the blood vessel wall. Utility Model Content

[0004] Therefore, it is necessary to provide a multi-layer delivery sheath with good skin penetration performance to address the above problems, so as to improve surgical efficiency and success rate. The multi-layer delivery sheath includes: a tube body extending along the central axis, wherein the tube body has an inner layer, a reinforcing layer and an outer layer bonded together from the inside to the outside; and a tip, wherein the tip is a single-layer structure and tapered in shape throughout the entire axial direction, and the tip is fixedly connected to the distal end of the tube body. The tip and the tube body are fixed to each other by a separate splicing method.

[0005] Furthermore, the length of the head end along the axial direction ranges from 2 to 6.5 mm.

[0006] Furthermore, the projection of the outer periphery of the head end onto the plane passing through the central axis is a straight line segment.

[0007] Furthermore, the cone angle of the head end ranges from 18 to 20 degrees.

[0008] Furthermore, the projection of the outer periphery of the head end onto the plane passing through the central axis is a curved segment.

[0009] Furthermore, the head end and the tube body are integrally formed after being heat-fused together.

[0010] Furthermore, the distal end of the head end is provided with rounded corners.

[0011] Furthermore, the radius of the fillet is in the range of 0.1-0.2 mm.

[0012] Furthermore, the outer layer is made of block polyether amide resin, and the head end is made of one of thermoplastic polyurethane elastomer, polyamide, polyethylene, polypropylene, polyvinyl chloride, or block polyether amide resin.

[0013] This application also relates to an adjustable bend conveyor system, including an adjustable bend conveyor and an expander. The adjustable bend conveyor includes a handle and the aforementioned multi-layer conveyor sheath, the proximal end of which is fixedly connected to the handle. The expander is inserted into the multi-layer conveyor sheath and its distal end extends out from the head end. The expander is interference-fitted with the head end.

[0014] The technical solution of this utility model has the following beneficial effects: This utility model adopts a split splicing method to construct a multi-layer delivery sheath with a single-layer head end, which has good flexibility and skin penetration performance, low puncture force and smooth delivery in blood vessels, and minimal damage to the blood vessel wall. Attached Figure Description

[0015] Figure 1 This is a structural diagram of the multi-layer delivery sheath.

[0016] Figure 2 This is an overall structural diagram of the adjustable bending conveyor system;

[0017] Figure 3 for Figure 2 Enlarged view of point A in the image; Detailed Implementation

[0018] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0019] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "upper," "lower," "left," "right," and similar expressions used to indicate orientation are for illustrative purposes only and do not represent the only possible implementation.

[0020] 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 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.

[0021] It should be noted that, for medical devices, the end of the medical device that is relatively closer to the operator is generally called the "proximal end," and the end that is relatively farther from the operator is called the "distal end." Based on this principle, the "proximal end" and "distal end" of any component of the delivery system are defined. "Proximal end" and "distal end" are only used to describe the orientation and do not refer to the end face of the proximal end or the end face of the distal end. "Axial axis" or "longitudinal axis" refers to the direction parallel to the line connecting the center of the distal end and the center of the proximal end of the medical device. "Radial axis" or "lateral axis" refers to the direction perpendicular to the axial direction.

[0022] First Embodiment

[0023] See Figure 1 As shown, this embodiment relates to a multi-layer delivery sheath 100, which has a central axis and includes a tube body 10 and a head end 20 fixedly connected to the distal end of the tube body 10. The tube body 10 has a multi-layer tube structure, consisting of an inner layer 13, a middle layer 12, and an outer layer 11 bonded together from the inside out. The inner layer 13 is the innermost layer of the tube body 10 made of polymer material, the middle layer 12 is a support layer embedded in or covering the inner layer 13, and the outer layer 11 is the outermost layer of the tube body 10 made of polymer material. The head end 20 has a single-layer structure, is generally conical in shape, and its outer diameter gradually decreases from the proximal end to the distal end.

[0024] The inner layer 13 is formed of a thermoplastic material with a special hardness, which can be composed of one or more of polytetrafluoroethylene (PTFE), polyethylene, and polyether block amide. In this embodiment, the inner layer 13 is made of PTFE, and the PTFE material forms the inner wall of the tube body 10, thereby making the inner wall of the tube body 10 smooth and facilitating the movement of other instruments within the inner cavity of the tube body 10.

[0025] An intermediate layer 12 is disposed on the inner layer 13. The intermediate layer 12 can be a single layer, which can be a braided layer or a helical spring layer. Alternatively, the intermediate layer can be a double layer, which includes both a braided layer and a helical spring layer. The braided layer is made of braided yarns, the cross-section of which can be flat or circular. The material can be 304 stainless steel, Nitinol, polyamide, or other suitable materials. The braided yarns are woven in a cross-hatching pattern to form the braided layer. The density of the braided layer can be uniform or vary from the distal end to the proximal end; for example, the seal gradually becomes denser from the proximal end to the distal end. The helical spring layer can also be made of 304 stainless steel, Nitinol, polyamide, or other suitable materials, with a circular cross-section and a constant or variable pitch; for example, the pitch gradually increases from the proximal end to the distal end. The intermediate layer 12 serves as a reinforcing layer, which, while ensuring the flexibility of the tube body 10, improves its structural strength, prevents deformation and twisting during the pushing process, and enhances the pushing performance and torque transmission performance of the tube body 10.

[0026] The outer layer 11 is a continuous monolith and can be produced by extrusion. The extruded material can be one or more thermoplastic materials with different hardnesses mixed in different proportions. The thermoplastic material includes one or more of polyether block amide, polyamide, polyurethane, polyethylene, or block polyether amide resin (PEBAX), and the hardness can be 35D, 63D, 55D, or 72D.

[0027] In this embodiment, the tube body 10 has a multi-layer structure, which provides good mechanical properties and passageability. Unlike the multi-layer structure of the tube body 10, the tip 20 in this embodiment is single-layered. The single-layered tip 20 is generally conical in shape, with its outer diameter gradually increasing from the distal to the proximal end. When the tip 20 is conical, its projection onto the plane passing through the central axis is either a straight line or a curve. When it is a straight line, its cone angle is 18 to 20 degrees. Furthermore, to facilitate entry of the tip 10 through the vascular puncture site and reduce damage to the vessel wall during movement within the blood vessel, a rounded corner with a radius of 0.1-0.2 mm can be provided at the distal end of the tip 10. The material of the tip 20 can be the same as or different from the outer layer 11, and can be one or more of TPU (thermoplastic polyurethane elastomer), PA (polyamide), PE (polyethylene), PP (polypropylene), PVC (polyvinyl chloride), or PEBAX.

[0028] See also Figure 1 As shown, a drawstring imaging ring 14 is also fixedly installed in the wall of the tube body 10. The drawstring imaging ring 14 is located on the distal side of the tube body 10 and near the head end 20. One end of the drawstring imaging ring 14 is connected to a drawstring (not shown in the figure). By pulling the drawstring, the drawstring imaging ring 14 can be adjusted and bent, thus making the multi-layer delivery sheath 100 a unidirectional or bidirectional adjustable bending sheath. In addition, the drawstring imaging ring 14 is made of imaging material and is used to visualize the actual position of the multi-layer delivery sheath 100 during surgery.

[0029] See Figure 2 As shown, Figure 2 An adjustable bending conveyor system 300 is disclosed, comprising an adjustable bending conveyor 200 and an expander 60 used in conjunction with it. The adjustable bending conveyor 200 includes a handle 50 and the aforementioned multi-layer conveying sheath 100. The handle 50 includes a Y-shaped connector 52, on which a rotating cylinder 51 is rotatably connected. The proximal end of the multi-layer conveying sheath 100 is fixedly connected to the Y-shaped connector 52. In this embodiment, the adjustable bending conveyor 200 also includes a bending wire (not shown in the figure). A slider (not shown in the figure) is disposed in the rotating cylinder 51. One end of the bending wire is connected to the drawing ring 14 of the multi-layer conveying sheath 100, and the other end is connected to the slider. Rotating the rotating cylinder 201 moves the slider, thereby actuating the bending wire to achieve adjustable bending of the multi-layer conveying sheath 100. The expander 60 includes an expander handle 61 and an expander body 62, with the expander handle 61 disposed on the proximal side of the expander body 62. The expander body 62 enters from the proximal inlet end of the Y-type connector 52, extends into the multi-layer delivery sheath 100, and at least partially extends out of the multi-layer delivery sheath 100.

[0030] See Figure 3 As shown, the distal inner diameter of the head end 20 of the multi-layer delivery sheath 100 is d5, while the outer diameter of the expander body 62 is D1. D1 is greater than d5, meaning that after the expander body 62 extends out from the head end 20 of the multi-layer delivery sheath 100, its connection with the head end 20 is an interference fit.

[0031] In existing technologies, due to manufacturing processes, the probe and dilator are clearance-fitted, meaning a gap exists between them. When the probe enters the blood vessel through the puncture site, the dilator, under pressure, will shift radially relative to the probe. For example, assuming the difference between the inner diameter of the probe and the outer diameter of the dilator is m, when the dilator shifts radially downwards, it will abut against the inner wall of the probe, resulting in a gap of at least 2m between the radially upper inner wall of the dilator and the probe (this gap will be greater than 2m when the probe deforms into an ellipse). This gap allows some tissue to enter the gap during the probe's entry into the blood vessel, or the portion of the probe on the gap side may scrape against the tissue, hindering the probe's entry into the blood vessel and causing damage to the puncture site and the blood vessel wall.

[0032] Compared to existing technologies, this embodiment reduces the size of the tip 20, allowing for an interference fit between the dilator body 62 and the tip 20 of the multilayer delivery sheath 100. On one hand, the reduced size of the tip 20 makes it easier to guide the multilayer delivery sheath 100 into the blood vessel; on the other hand, the interference fit eliminates the gap between the dilator 60 and the multilayer delivery sheath 100, thereby eliminating any obstruction to the tip's insertion into the skin and any damage to the blood vessel wall caused by this gap.

[0033] In existing processing techniques, the main body of the sheath and the tip (TIP) are typically integrally molded, with the TIP formed at the distal end of the sheath using a specific mold. When the sheath body has a three-layer or other multi-layer structure, the tip is generally a two- or three-layer structure due to the integral molding method. For example, when the sheath body includes an innermost PTFE layer, a middle reinforcing layer, and an outermost PEBAX layer, the tip is generally a two-layer structure, consisting of an inner PTFE layer and an outer PEBAX layer. Because the tip has a two-layer structure, during diameter reduction processing, the inner PTFE layer and the outer PEBAX layer have different melting points and shrinkage rates, making separation of the inner and outer layers likely. Furthermore, the greater the diameter reduction, the greater the difference in shrinkage rates between the PTFE and PEBAX layers, increasing the likelihood of separation. Therefore, due to the limitations of the aforementioned processing, the tip of a two-layer structure cannot be reduced to the predetermined size. Additionally, the tip of a two-layer structure experiences greater friction during skin insertion, making separation of the inner and outer layers more likely and leading to insertion failure. Even if a single-layer PEBAX structure can be formed using a one-piece molding process, this single-layer structure is only a partial structure of the tip head. It is only a small part extending from the end of the overall tip head, while the rest of the tip head remains a double-layer structure. For example, when the entire tip head has an axial length of 2-3 mm, the single-layer PEBAX structure extending to the end is only 0.25-1 mm, and it is impossible to form a single-layer structure throughout the entire length of the tip head.

[0034] Unlike existing processing techniques, this invention uses a modular molding and splicing method to form the tip. Because this application uses a modular splicing method, the entire tip 20 is a single-layer structure. Compared to a double-layer structure, this single-layer tip has better flexibility due to its only flexible layer (such as a PEBAX layer). Furthermore, the modular splicing process allows for the manufacture of smaller tips, enabling interference fit with other devices such as dilators, thus facilitating insertion into blood vessels and eliminating the problem of inner and outer layer separation common in TIP tips. Additionally, compared to a one-piece molding method, the modular splicing method minimizes the influence of the multi-layer main tube 10 on the shape and length of the tip 20 during molding, allowing for the creation of single-layer tips 10 with specific shapes and sizes according to actual needs. For example, the axial length of the tip of the multi-layer delivery sheath 100 is 2-6.5 mm, a length that cannot be achieved using a one-piece molding process.

[0035] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. The protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A multi-layer conveying sheath, characterized in that, include: The tube body extends along the central axis, and the tube body has an inner layer, a reinforcing layer and an outer layer that are bonded to each other from the inside to the outside; The head end is a single-layer structure with a tapered shape throughout the entire axial direction. The head end is fixedly connected to the far end of the tube body, and the head end and the tube body are fixed to each other by a separate splicing method.

2. The multi-layer conveying sheath according to claim 1, characterized in that, The length of the head end along the axial direction ranges from 2 to 6.5 mm.

3. The multi-layer conveying sheath according to claim 1, characterized in that, The projection of the outer periphery of the head end onto a plane passing through the central axis is a straight line segment.

4. The multi-layer conveying sheath according to claim 3, characterized in that, The cone angle at the head end ranges from 18 to 20 degrees.

5. The multi-layer conveying sheath according to claim 1, characterized in that, The projection of the outer periphery of the head end onto a plane passing through the central axis is a curved segment.

6. The multi-layer conveying sheath according to claim 1, characterized in that, The head end is integrally formed with the tube body after being heat-fused.

7. The multi-layer conveying sheath according to claim 1, characterized in that, The distal end of the head is provided with rounded corners.

8. The multi-layer conveying sheath according to claim 7, characterized in that, The radius of the fillet is in the range of 0.1-0.2 mm.

9. The multi-layer conveying sheath according to claim 1, characterized in that, The outer layer is made of block polyether amide resin, and the head end is made of thermoplastic polyurethane elastomer, polyamide, polyethylene, polypropylene, polyvinyl chloride, or block polyether amide resin.

10. An adjustable bending conveyor system, comprising an adjustable bending conveyor and an expander, characterized in that, The adjustable bending conveyor includes a handle and a multi-layer conveying sheath as described in any one of claims 1-9. The proximal end of the multi-layer conveying sheath is fixedly connected to the handle. The expander is inserted into the multi-layer conveying sheath and its distal end extends out from the head end. The expander is interference-fitted with the head end.

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