Sheath assembly

Abstract

The utility model relates to a sheath assembly. The catheter comprises a catheter body, a traction line and a traction mechanism, the catheter body comprises a first extension section, a bent section and a second extension section which are sequentially arranged in the length direction of the catheter body, the first extension section is longer than the second extension section, and the bent section is bent and shaped to enable the first extension section and the second extension section to be arranged in parallel. One end of the pull wire is connected to the second extending section, and the pull wire is arranged along the pipe wall of the catheter and arranged in the pipe wall of the catheter. The traction mechanism is arranged at the end, away from the bent section, of the first extension section. The traction mechanism is connected with the other end of the traction line and used for pulling the traction line to move along the pipe walls of the first braided pipe and the bent braided pipe so as to change the bending angle of the bent section. The bending section is arranged to be of the bending structure, the traction line adjusts the bending section to be in the linear state from the bending state, the bending section provides support for the traction line, the overall structure of the first extension section and the second extension section of the catheter is not affected, and the bending adjusting precision of the catheter is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a sheath assembly. BACKGROUND

[0002] With the development of medical technology, adjustable bending sheath technology appears, which is usually used in the operation of endoscopes, catheters and the like during the process of reading; the operator adjusts the operation handle manually to pull the pull wire to adjust the bending angle of the front end of the adjustable bending sheath, so as to adapt to the complex bending environment in the pipeline such as blood vessels in the human body, extend the front end of the adjustable bending sheath to the treatment area in the human body, and make the patient's body stable communication with the outside, so as to facilitate the relevant operation.

[0003] In the related art, the front end of the adjustable bending sheath is linear, and a plurality of pull wires are arranged along the sheath. When operating, the corresponding pull wire needs to be pulled tight by the operation handle to drive the front end of the adjustable bending sheath to bend, and the bending angle of the front end of the adjustable bending sheath is adjusted according to the tightness of the pull wire.

[0004] However, by adjusting the adjustable bending sheath in the above manner, since the front end of the sheath is a linear structure, when the pull wire is pulled tight, the middle part of the sheath needs to provide a supporting force to the pull wire, so that the end of the pull wire can exert a force on the front end of the sheath. Since the middle part of the sheath bears a large force, when the front end of the sheath is bent, the middle part of the sheath is also bent, so that the whole sheath forms an arc shape, resulting in a too large bending radius that is not easy to control, which affects the bending control precision of the sheath. CONTENT OF THE INVENTION

[0005] Therefore, it is necessary to provide a sheath assembly to solve the problem of low control precision of the sheath.

[0006] This application provides a sheath assembly comprising: a catheter including a first extension, a curved section, and a second extension sequentially arranged along the length of the catheter, wherein the length of the first extension is greater than the length of the second extension, and the curved section is curved such that the first extension and the second extension are arranged parallel to each other; the first extension includes a first braided tube arranged along the length of the first extension, the first braided tube being located in the middle of the tube wall of the first extension; the curved section includes a curved braided tube arranged along the length of the curved section, the curved braided tube being located in the middle of the tube wall of the curved section, and one end of the first braided tube and one end of the curved braided tube being connected. A traction line, the distal end of which is connected to the second extension, the traction line being arranged along the first braided tube and the curved braided tube, and disposed inside the tube walls of the first braided tube and the curved braided tube. A traction mechanism, disposed at the end of the first extension away from the curved section; the traction mechanism is connected to the proximal end of the traction line, for pulling the traction line along the tube walls of the first braided tube and the curved braided tube to change the bending angle of the curved section.

[0007] In some embodiments, the first extension section further includes a first inner tube and a first outer tube, with the first braided tube sleeved around the outer periphery of the first inner tube and the first outer tube sleeved around the outer periphery of the first braided tube. The curved section further includes a curved inner tube and a curved outer tube arranged along the length of the curved section, with the curved braided tube sleeved around the outer periphery of the curved inner tube and the curved outer tube sleeved around the outer periphery of the curved braided tube; wherein one end of the first inner tube is connected to one end of the curved inner tube; and one end of the first outer tube is connected to one end of the curved outer tube. The second extension section includes a second outer tube, with one end of the second outer tube connected to the other end of the curved outer tube; the traction line is connected to the second outer tube.

[0008] In some embodiments, the traction line is located outside the curved section and extends axially along the first braided tube and the curved braided tube.

[0009] In some embodiments, the catheter further includes a transition section located between the first extension section and the bend section, the first extension section and the bend section being connected by the transition section; the transition section extends along the length direction of the first extension section.

[0010] In some embodiments, the transition section comprises a transition inner layer tube, a transition braided tube and a transition outer layer tube, the transition braided tube is sleeved on the outer periphery of the transition inner layer tube, and the transition outer layer tube is sleeved on the outer periphery of the transition braided tube; the first inner layer tube and the curved inner layer tube are connected through the transition inner layer tube and are integrally arranged with the transition inner layer tube; the first braided tube and the curved braided tube are connected through the transition braided tube and are integrally arranged with the transition braided tube; the first outer layer tube and the curved outer layer tube are connected through the transition outer layer tube and are integrally arranged with the transition outer layer tube.

[0011] In some embodiments, the braiding density of the curved braided tube is greater than the braiding density of the first braided tube and the transition braided tube.

[0012] In some embodiments, the material hardness of the first outer layer tube is denoted as H1, the material hardness of the transition outer layer tube is denoted as H2, and the material hardness of the curved outer layer tube is denoted as H3, and the material hardness relationship is H1>H2>H3.

[0013] In some embodiments, the sheath assembly further comprises a connecting ring, which is arranged on the second extension section and connected with the distal end of the traction line.

[0014] In some embodiments, the sheath assembly further comprises a developing ring, which is arranged on the second extension section away from the curved section.

[0015] In some embodiments, the traction mechanism comprises a handle, a knob and a storage mechanism, one end of the storage mechanism is connected with the proximal end of the traction line, the other end of the storage mechanism is connected with the knob, and the knob is used to drive the storage mechanism to pull the traction line; the handle is sleeved on the outer periphery of the storage mechanism, and the knob is located at the end of the handle away from the traction line.

[0016] In the aforementioned sheath assembly, since the length of the first extension is greater than the length of the second extension, the curved section is located near the front end of the catheter. The curved section is bent so that the first and second extensions at both ends of the curved section are parallel to each other. The catheter has a multi-layered structure. The traction line is located in the first braided tube in the middle of the wall of the first extension and in the curved extension in the middle of the wall of the curved extension. The first braided tube and the curved braided tube provide support for the traction line. The distal end of the traction line is connected to the second extension, and the proximal end of the traction line is connected to a traction mechanism located at one end of the first extension of the catheter. By adjusting the traction mechanism, pulling the traction line can move the second extension. Since the first and second extensions are parallel after turning through the curved section, when the traction line is pulled, the second extension is pulled away from the first extension, causing the curved section to change from a curved state to a straight state. When the traction line is not pulled, the curved section returns to its initial curved state and drives the second extension to pull the traction line back to its original state. Thus, by changing the length of the traction line, the angle of the second extension relative to the first extension can be adjusted. By setting the curved section near the catheter tip as a curved structure, the position of the catheter tip can be adjusted from a curved state to a straight state using a traction line. This places the traction line's support force at the curved section. Since the curved section provides support for the traction line, it does not affect the overall structure of the first and second extension sections of the catheter, thus improving the accuracy of the catheter's bending adjustment. In addition, the curved section sets the first and second extension sections at both ends to be parallel, allowing for a wider range of adjustable angles. Attached Figure Description

[0017] Figure 1 This is a visual diagram of the overall structure of a sheath assembly according to one embodiment of the present application.

[0018] Figure 2 This is a cross-sectional view of the sheath assembly along the plane containing the catheter axis at one embodiment of the present application.

[0019] Figure 3 This application provides an embodiment of a sheath assembly. Figure 2 Enlarged view of point A in the middle.

[0020] Figure 4 This application provides an embodiment of a sheath assembly. Figure 2 Enlarged view of point B in the middle.

[0021] Figure 5 This application provides an embodiment of a sheath assembly. Figure 2 Enlarged view of point C in the middle.

[0022] Figure 6 This application provides an embodiment of a sheath assembly. Figure 2 Sectional view at point D.

[0023] In the figure, 100, catheter; 110, first extension section; 111, first braided tube; 112, first inner layer tube; 113, first outer layer tube; 120, bending section; 121, bending braided tube; 122, bending inner layer tube; 123, bending outer layer tube; 130, second extension section; 131, second outer layer tube; 140, transition section; 141, transition braided tube; 142, transition inner layer tube; 143, transition outer layer tube; 200, pull wire; 300, pulling mechanism; 310, handle; 320, knob; 400, connecting ring; 500, developing ring. DETAILED DESCRIPTION

[0024] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways beyond the specific embodiments described herein and by one of ordinary skill in the art without departing from the spirit and scope of the present application, and it is therefore intended that all such variations be considered as falling within the scope of the present application. It should be understood that the descriptions of the present application are merely intended to be illustrative and that changes can be made to the description without departing from the spirit of the present application.

[0025] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only intended to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0026] In addition, if the terms "first", "second" appear, these terms are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implying the number of the technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "multiple" appears, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0027] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", and the like, should be understood broadly. For example, it can be fixedly connected, or detachably connected, or integrated; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal communication of two elements, or the interaction relationship between two elements, unless otherwise explicitly defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] In the present application, unless specifically defined otherwise, if there is a description such as "on" or "under" or the like between the first feature and the second feature, it can mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0029] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are only for illustrative purposes and do not represent the only implementation.

[0030] Reference Figure 1 , Figure 1The appearance schematic diagram of the sheath assembly in the embodiment of the present application is shown, and the sheath assembly provided by the embodiment of the present application comprises a catheter 100, a traction line 200 and a traction mechanism 300. The catheter 100 comprises a first extension section 110, a bending section 120 and a second extension section 130 arranged in sequence along the length direction of the catheter 100. The length of the first extension section 110 is greater than the length of the second extension section 130, and the bending section 120 is bent and shaped so that the first extension section 110 and the second extension section 130 are arranged in parallel. The first extension section 110 comprises a first braided tube 111 arranged along the length direction of the first extension section 110, and the first braided tube 111 is located in the middle part of the tube wall of the first extension section 110. The bending section 120 comprises a bending braided tube 121 arranged along the length direction of the bending section 120, and the bending braided tube 121 is located in the middle part of the tube wall of the bending section 120. One end of the first braided tube 111 is connected to one end of the bending braided tube 121. The distal end of the traction line 200 is connected to the second extension section 130, and the traction line 200 is arranged along the first braided tube 111 and the bending braided tube 121 and located inside the tube wall of the first braided tube 111 and the bending braided tube 121. The traction mechanism 300 is arranged at the end of the first extension section 110 away from the bending section 120. The traction mechanism 300 is connected to the proximal end of the traction line 200 and used to pull the traction line 200 to move along the tube wall of the first braided tube 111 and the bending braided tube 121 so as to change the bending angle of the bending section 120.

[0031] Referring to Figure 1 , Figure 2 , Figure 3 and Figure 5 , it should be noted that the bending section 120 is heat-set during production so that the bending section 120 is bent by 180° in the state without external force, that is, the two ends of the bending section 120 are arranged in the same direction. One end of the first extension section 110 is connected to one end of the bending section 120, and one end of the second extension section 130 is connected to the other end of the bending section 120, so that the first extension section 110 and the second extension section 130 are arranged in parallel. The second extension section 130 is the front end of the catheter 100, and when the sheath assembly is used, the end of the second extension section 130 of the catheter 100 guides the remaining part of the catheter 100 to enter the patient's body. Since the length of the first extension section 110 is greater than the length of the second extension section 130, the bending section 120 is located close to the front end of the catheter 100. The traction mechanism 300 is arranged at the other end of the first extension section 110 and located outside the patient's body during use, which is convenient for the operator to operate.

[0032] The first braided tube 111 and the curved braided tube 121 are located in the middle of the tube wall and have a certain strength. The pull wire 200 is arranged in the tube wall of the first braided tube 111 and the curved braided tube 121. The tube wall of the first braided tube 111 and the curved braided tube 121 can provide stable support and protection for the structure of the pull wire 200. The pull wire 200 is not easily affected by external conditions during movement, and the movement accuracy of the pull wire 200 is ensured.

[0033] Since the bending angle of the curved section 120 is 180°, on the one hand, when the traction mechanism 300 pulls the pull wire 200, the pull wire 200 drives the second extension section 130 to move away from the traction mechanism 300, and the second extension section 130 drives the curved section 120 to change from a curved state to a straight state, thereby reducing the bending angle of the curved section 120. When the pull wire 200 is released, the curved section 120 returns to the initial state under the action of no external force, thereby increasing the bending angle of the curved section 120, that is, the bending angle of the catheter 100 changes in the range of 0°-180°, and the applicability of the catheter 100 is higher. On the other hand, in the process of pulling the pull wire 200, the pull wire 200 abuts against the bent part of the curved section 120, and the curved section 120 provides support force for the turning of the pull wire 200. Other parts of the catheter 100 will not be subjected to the force of the pull wire 200 along the radial direction of the catheter 100. Therefore, it can be ensured that only the curved section 120 adjusts the bending angle of the catheter 100, and the control accuracy of the bending angle of the catheter 100 can be improved.

[0034] In use, the operator holds the traction mechanism 300 and operates the traction mechanism 300 to pull the pull wire 200, so that the curved section 120 is adjusted to a suitable bending angle. The second extension section 130 is placed in the patient's body and pushed forward. During the pushing process, the operator tightens or loosens the pull wire 200 according to the actual situation to adjust the bending angle of the front end of the catheter 100, so that the catheter 100 can advance in the specified direction according to the angle of the pipeline in the human body.

[0035] Through the above arrangement, it can be ensured that when the bending angle of the catheter 100 is adjusted, only the side wall of the curved section 120 of the catheter 100 will be subjected to the force along the radial direction of the catheter 100, and other parts of the catheter 100 will not be subjected to the force along the radial direction of the catheter 100. The catheter 100 will not be deformed due to the force of the pull wire 200. The bending of multiple parts of the catheter 100 is avoided, so that the overall bending angle of the catheter 100 is not easy to control. Therefore, the adjustment accuracy of the bending angle of the catheter 100 can be improved. The adjustable bending angle of the curved section 120 is 0°-180°, and the applicability is higher. The first braided tube 111 and the curved braided tube 121 can provide support and protection for the pull wire 200, and further improve the operation accuracy of pulling the pull wire 200.

[0036] In some embodiments, the first extension section 110 further comprises a first inner layer tube 112 and a first outer layer tube 113, the first braided tube 111 is sleeved on the outer periphery of the first inner layer tube 112, and the first outer layer tube 113 is sleeved on the outer periphery of the first braided tube 111. The bending section 120 further comprises a bending inner layer tube 122 and a bending outer layer tube 123 arranged along the length direction of the bending section 120, the bending braided tube 121 is sleeved on the outer periphery of the bending inner layer tube 122, and the bending outer layer tube 123 is sleeved on the outer periphery of the bending braided tube 121; wherein one end of the first inner layer tube 112 is connected to one end of the bending inner layer tube 122, and one end of the first outer layer tube 113 is connected to one end of the bending outer layer tube 123. The second extension section 130 comprises a second outer layer tube 131, one end of the second outer layer tube 131 is connected to the other end of the bending outer layer tube 123; the traction line 200 is connected to the second outer layer tube 131.

[0037] Referring to Figure 2 , Figure 3 , Figure 5 and Figure 6 , it should be noted that the first extension section 110 and the bending section 120 are three-layer tube structures, which increase the stability of the catheter 100, and the corresponding tube walls of each layer of the first extension section 110 and the bending section 120 are connected to form the basic structure of the catheter 100; the second extension section 130 can be provided as a single-layer tube structure for easy adjustment. Preferably, since the first inner layer tube 112, the first outer layer tube 113, the bending inner layer tube 122 and the bending outer layer tube 123 are directly in contact with the human body, medical materials are used to ensure safety in use. The first braided tube 111 and the bending braided tube 121 use materials with certain strength, which can provide support for the whole catheter 100 and cooperate with the traction line 200 to change the bending angle of the bending section 120.

[0038] In some embodiments, the traction line 200 is located on the outer side of the bending section 120 and extends along the axial direction of the first braided tube 111 and the bending braided tube 121.

[0039] Referring to Figure 1 and Figure 2 , it should be noted that when no pulling force is applied to the traction line 200, the length of the inner side of the bending section 120 is shorter than the length of the outer side of the bending section 120, the traction line 200 is arranged on the outer side of the bending section 120, and by extending the traction line 200 along the axial direction of the first braided tube 111 and the bending braided tube 121, the distal end of the traction line 200 is connected to the side of the second extension section 130 away from the first extension section 110, so that when the traction line 200 is pulled, compared to the connection of the traction line 200 to other positions of the second extension section 130, this way can more easily move the second extension section 130 away from the first extension section 110, which is convenient for the operator to use.

[0040] In some embodiments, the catheter 100 further comprises a transition section 140, which is located between the first extension section 110 and the bending section 120, and connects the first extension section 110 and the bending section 120; the transition section 140 extends along the length direction of the first extension section 110.

[0041] Referring to Figure 2 It should be noted that the length direction of the transition section 140 is the same as the length direction of the first extension section 110, and the first extension section 110, the transition section 140, the bending section 120 and the second extension section 130 form the overall structure of the catheter 100. The transition section 140 is made of different materials from the first extension section 110, and the first extension section 110 and the bending section 120 are easier to connect in the production process through the transition section 140.

[0042] In some embodiments, the transition section 140 comprises a transition inner layer tube 142, a transition braided tube 141 and a transition outer layer tube 143, the transition braided tube 141 is sleeved on the outer periphery of the transition inner layer tube 142, and the transition outer layer tube 143 is sleeved on the outer periphery of the transition braided tube 141; the first inner layer tube 112 and the bending inner layer tube 122 are connected through the transition inner layer tube 142, and are integrally arranged with the transition inner layer tube 142; the first braided tube 111 and the bending braided tube 121 are connected through the transition braided tube 141, and are integrally arranged with the transition braided tube 141; the first outer layer tube 113 and the bending outer layer tube 123 are connected through the transition outer layer tube 143, and are integrally arranged with the transition outer layer tube 143.

[0043] Referring to Figure 2 and Figure 4 It should be noted that the transition section 140 is a three-layer tube structure, and each layer of the transition section 140 is connected with the corresponding layer of the first extension section 110 and the corresponding layer of the bending section 120 to form an overall structure. The first braided tube 111, the transition braided tube 141 and the bending braided tube 121 are integrally arranged, the first inner layer tube 112, the transition inner layer tube 142 and the bending inner layer tube 122 are integrally arranged, and the first outer layer tube 113, the transition outer layer tube 143 and the bending outer layer tube 123 are integrally arranged, which can improve the sealing performance of the connection between the sections of the catheter 100, and improve the processing and production efficiency in the production process.

[0044] In some embodiments, the braiding density of the bending braided tube 121 is greater than the braiding density of the first braided tube 111 and the transition braided tube 141.

[0045] It should be noted that the first braided tube 111 and the curved braided tube 121 are woven with stainless steel wires, which can improve the support strength and be easily bent, so that the bending angle of the curved braided tube 121 can be adjusted by the traction wire 200. The braided density of the curved braided tube 121 is relatively high, which can provide high strength and ensure that the traction wire 200 can provide stable steering force during the pulling of the traction wire 200, and is not easy to break and leak. In contrast, the strength of the first braided tube 111 and the transition braided tube 141 can be set lower, which can save production cost and production time.

[0046] In some embodiments, the material hardness of the first outer layer tube 113 is denoted as H1, the material hardness of the transition outer layer tube 143 is denoted as H2, and the material hardness of the curved outer layer tube 123 is denoted as H3. The relationship between the material hardnesses is H1>H2>H3.

[0047] It should be noted that the materials of the curved outer layer tube 123 and the second outer layer tube 131 are the same nylon elastomer, which has good elasticity and is convenient for the curved outer layer tube 123 to deform with the curved braided tube 121. The material of the transition outer layer tube 143 is a nylon elastomer, and the material hardness of the transition outer layer tube 143 is slightly higher than that of the curved outer layer tube 123, so that the transition outer layer tube 143 is not easy to deform compared with the curved outer layer tube 123, thereby avoiding the traction wire 200 from bending the transition section 140; when the traction wire 200 pulls the curved section 120 to a straight state, the transition section 140 can slightly deform under the pulling of the traction wire 200, as a buffer, and the operator can more obviously perceive the increase in the force required to continue to tighten the traction wire 200 in this process, thereby reminding the operator not to continue the tightening operation, so as to avoid the traction wire 200 from pulling the first extension section 110.

[0048] The material of the first outer layer tube 113 is endo-12-lactam, which has higher material hardness than the curved outer layer tube 123 and is not easy to deform, so as to increase the strength of the first extension section 110 to a certain extent and ensure that the first extension section 110 can remain in a straight state when adjusting the traction wire 200. When the transition section 140 and the first extension section 110 move in the human body and contact the in-vivo tissue, they can be bent under the action of the in-vivo tissue to prevent the transition section 140 and the first extension section 110 from being too hard to cause damage to the in-vivo tissue.

[0049] In addition, the materials of the first inner layer tube 112 and the curved inner layer tube 122 are relatively soft polytetrafluoroethylene, which ensures that the curved inner layer tube 122 deforms with the curved braided tube 121. The materials of the outer layer tube and the inner layer tube are not soluble in water and do not react with substances in the human body, ensuring safety in use.

[0050] Referring to Figure 2In some embodiments, the sheath assembly further comprises a connecting ring 400, which is arranged at the second extension segment 130 and connected to the distal end of the traction line 200.

[0051] It should be noted that the end of the curved woven tube 121 is connected to the inner wall of the connecting ring 400, so that the connection between the curved segment 120 and the second extension segment 130 is more stable; the connecting ring 400 is arranged inside the second extension segment 130 to provide support for the second extension segment 130.

[0052] In some embodiments, the sheath assembly further comprises a developing ring 500, which is arranged at the end of the second extension segment 130 away from the curved segment 120.

[0053] It should be noted that the developing ring 500 is arranged at the end of the second extension segment 130, i.e., the most front end of the catheter 100, so that it can cooperate with other medical devices to display the position of the developing ring 500, and facilitate the operator to understand the position and use state of the catheter 100.

[0054] Referring to Figure 1 In some embodiments, the traction mechanism 300 comprises a handle 310, a knob 320, and a storage mechanism (not shown in the figure), one end of the storage mechanism is connected to the proximal end of the traction line 200, the other end of the storage mechanism is connected to the knob 320, and the knob 320 is used to drive the storage mechanism to pull the traction line 200; the handle 310 is sleeved on the outer periphery of the storage mechanism, and the knob 320 is located at the end of the handle 310 away from the traction line 200.

[0055] It should be noted that, in use, the clockwise rotation of the knob 320 can drive the storage mechanism to store the traction line 200 in the storage mechanism, thereby shortening the traction line 200 and reducing the bending angle of the curved segment 120; the counterclockwise rotation of the knob 320 releases the traction line 200 from the storage mechanism, thereby increasing the bending angle of the curved segment 120. By cooperating the knob 320 with the storage mechanism, the bending angle of the curved segment 120 can be accurately adjusted, and the knob 320 can be fixed to keep the curved segment 120 at a certain angle for use without artificial fixing. The handle 310 is installed outside the storage mechanism to protect the storage mechanism from being damaged.

[0056] The technical features of the above-described embodiments can be combined arbitrarily, and to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present disclosure.

[0057] The above embodiments only express several implementation ways of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation to the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A sheath assembly, comprising: The catheter comprises a first extension section, a bending section and a second extension section arranged in sequence along the length direction of the catheter, the length of the first extension section is greater than the length of the second extension section, and the bending section is bent and shaped so that the first extension section and the second extension section are arranged in parallel; the first extension section comprises a first braided tube arranged along the length direction of the first extension section, and the first braided tube is located in the middle of the tube wall of the first extension section; the bending section comprises a bending braided tube arranged along the length direction of the bending section, and the bending braided tube is located in the middle of the tube wall of the bending section, one end of the first braided tube and one end of the bending braided tube are connected; a traction line is connected to the second extension section at the distal end, the traction line is arranged along the first braided tube and the bending braided tube and is located inside the tube wall of the first braided tube and the bending braided tube; a traction mechanism is arranged at the end of the first extension section away from the bending section; the traction mechanism is connected to the proximal end of the traction line and is used to pull the traction line to move along the tube wall of the first braided tube and the bending braided tube to change the bending angle of the bending section. The first extension section further comprises a first inner layer tube and a first outer layer tube, the first braided tube is sleeved on the outer periphery of the first inner layer tube, and the first outer layer tube is sleeved on the outer periphery of the first braided tube; 2. The sheath assembly of claim 1, wherein, The bending section further comprises a bending inner layer tube and a bending outer layer tube arranged along the length direction of the bending section, the bending braided tube is sleeved on the outer periphery of the bending inner layer tube, and the bending outer layer tube is sleeved on the outer periphery of the bending braided tube; one end of the first inner layer tube is connected to one end of the bending inner layer tube; one end of the first outer layer tube is connected to one end of the bending outer layer tube; The second extension section comprises a second outer layer tube, one end of the second outer layer tube is connected to the other end of the bending outer layer tube; the traction line is connected to the second outer layer tube. The traction line is located outside the bending section and extends along the axial direction of the first braided tube and the bending braided tube.

3. The sheath assembly of claim 2, wherein, The catheter further comprises a transition section between the first extension section and the bending section, and the first extension section and the bending section are connected through the transition section; the transition section extends along the length direction of the first extension section.

4. The sheath assembly of claim 2, wherein, The transition section comprises a transition inner layer tube, a transition braided tube and a transition outer layer tube, the transition braided tube is sleeved on the outer periphery of the transition inner layer tube, and the transition outer layer tube is sleeved on the outer periphery of the transition braided tube; the first inner layer tube and the bending inner layer tube are connected through the transition inner layer tube and are arranged integrally with the transition inner layer tube; the first braided tube and the bending braided tube are connected through the transition braided tube and are arranged integrally with the transition braided tube; the first outer layer tube and the bending outer layer tube are connected through the transition outer layer tube and are arranged integrally with the transition outer layer tube.

5. The sheath assembly of claim 4, wherein, The braiding density of the bending braided tube is greater than the braiding density of the first braided tube and the transition braided tube.

6. The sheath assembly of claim 5, wherein, ​ 7. The sheath assembly of claim 5, wherein, The material hardness of the first outer tube is denoted as H1, the material hardness of the transition outer tube is denoted as H2, and the material hardness of the curved outer tube is denoted as H3, and the material hardness relationship is H1>H2>H3.

8. The sheath assembly of claim 1, wherein, The connecting ring is arranged on the second extension section and connected to the distal end of the traction line.

9. The sheath assembly of claim 1, wherein, The developing ring is arranged on the second extension section away from the curved section.

10. The sheath assembly of claim 1, wherein, The traction mechanism comprises a handle, a knob and a receiving mechanism, one end of the receiving mechanism is connected to the proximal end of the traction line, the other end of the receiving mechanism is connected to the knob, the knob is used to drive the receiving mechanism to pull the traction line; the handle is sleeved on the outer periphery of the receiving mechanism, and the knob is located at the end of the handle away from the traction line.

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