Introducer sheath and sheath assembly

Abstract

The present application belongs to the field of medical device technology, and specifically relates to a guide sheath and sheath tube assembly. The sheath tube assembly includes a sheath tube, a retainer and a driving mechanism, and the sheath tube includes a first tube segment and a second tube segment distributed in sequence in the direction extending from its own proximal end to the distal end; the first tube segment is slidably sleeved with the second tube segment, and one of the distal end of the first tube segment and the proximal end of the second tube segment is provided with an expandable portion, one end of the retainer is connected to the second tube segment, and the other end is connected to the first tube segment or the operating handle of the guide sheath to fix the length of the sheath tube; the expandable portion can switch between an expanded state and a contracted state, and the driving mechanism can switch the expandable portion from a contracted state to an expanded state. The present application can solve the problem of easy jamming when using the current sheath tube to aspirate stones and wait for the aspirated material.

Description

Technical Field

[0001] The present application belongs to the field of medical device technology, and specifically relates to a guide sheath and sheath tube assembly. Background Art

[0002] Guide sheaths are commonly used in urological endoscopic examinations or surgeries. They can establish a surgical channel in the urinary system to assist the endoscope and surgical instruments in passing through the urethra, ureter and other cavities, thereby improving the effectiveness and safety of examinations and treatments.

[0003] When using a guide sheath to remove kidney stones, the guide sheath can be inserted into the kidney using a guide wire, and then the insertion portion of the endoscope can be inserted into the sheath to observe and break the stones. When the stone is on the side of the sheath, the insertion portion can be used to drive the distal end of the sheath to bend, so that the sheath is directed toward the stone and the stone is sucked into the gap between the insertion portion and the sheath, thereby expelling the stone. However, in practice, when the insertion portion is used to drive the distal end of the sheath to bend to suck the lateral stone, the problem of unsmooth stone removal is prone to occur. Summary of the invention

[0004] The purpose of the present application is to provide a guide sheath and sheath tube assembly, which can solve the problem of easy jamming when using the current sheath tube to aspirate stones and wait for the aspirated material.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, the present application provides a sheath assembly, which is applied to a guide sheath, and includes a sheath, a retainer, and a drive mechanism, wherein the sheath includes a first tube segment and a second tube segment sequentially distributed in a direction extending from its proximal end to its distal end;

[0007] The first tube segment is slidably sleeved with the second tube segment, an expandable portion is provided at the distal end of the first tube segment and the proximal end of the second tube segment, one end of the retainer is connected to the second tube segment, and the other end is connected to the first tube segment or the operating handle of the guide sheath to fix the length of the sheath tube;

[0008] The expandable portion can switch between an expanded state and a contracted state. When the expandable portion is in the expanded state, at least a portion of the expandable portion radially protrudes outward from other portions of the sheath, and a flow area of ​​a first inner cavity of the expandable portion is larger than a flow area of ​​a second inner cavity of other portions of the sheath; when the expandable portion is in the contracted state, at least a portion of the expandable portion is flush with or radially protrudes inward from other portions of the sheath, and a flow area of ​​the first inner cavity is smaller than or equal to a flow area of ​​the second inner cavity;

[0009] The drive mechanism can switch the expandable portion from a contracted state to an expanded state.

[0010] In a second aspect, the present application provides a guide sheath comprising the above-mentioned sheath tube assembly.

[0011] The beneficial technical effects of this application are as follows:

[0012] In the present application, the expandable portion can switch between a contracted state and an expanded state. Before the sheath is inserted into the human body, the expandable portion can be switched to the contracted state. At this time, at least part of the expandable portion is flush with or radially convex to other parts of the sheath, that is, all parts of the expandable portion do not radially convex to other parts of the sheath, thereby facilitating the insertion of the sheath into the human body.

[0013] When the sheath is inserted into the human body and it is necessary to aspirate the stones to be aspirated, the driving mechanism can be used to switch the expandable part from the contracted state to the expanded state, and then the insertion part of the endoscope can be inserted into the sheath. The active bending section of the insertion part can drive at least part of the sheath tube section close to its own distal opening to bend. Because the active bending section is bending, different parts of the active bending section will press against the specific position of the sheath tube, so that the maximum distance between each part of the bent active bending section in the direction of its own extension and the inner wall of the tube section of the sheath tube bent by the active bending section is constantly changing. After the expandable part of the present application is in the expanded state, the size of the first inner cavity of the expandable part is larger than the size of the second inner cavity of other parts of the sheath tube. In this way, the expandable part can be used to increase the minimum value of each maximum distance, so that the minimum value of each maximum distance is greater than the size of the target object in the object to be aspirated. In this way, the target object can smoothly pass through the gap between the bent active bending section and the inner wall of the tube section of the sheath tube bent by the active bending section, thereby solving the problem of unsmooth discharge of the object to be aspirated.

[0014] Furthermore, the present application also fixes the length of the sheath by a retaining member, thereby preventing the length of the sheath from changing when the expandable portion expands or contracts, thereby preventing the relative position between the distal opening of the second tube segment and the object to be aspirated from changing, thereby eliminating the need to adjust the position of the sheath and the endoscope to direct the distal opening of the sheath toward the object to be aspirated, thereby simplifying the operating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the cooperation between the curved sheath tube and the curved active curved section disclosed in the prior art, and a schematic cross-sectional diagram along line a to line g;

[0016] Figure 2 It is a schematic structural diagram of the sheath tube assembly when the expandable portion disclosed in the embodiment of the present application is in a contracted state;

[0017] Figure 3 It is a schematic diagram of the structure of the sheath tube assembly after the skin is hidden when the expandable portion disclosed in the embodiment of the present application is in a contracted state;

[0018] Figure 4 A cross-sectional view of the sheath tube assembly after the skin is hidden when the expandable portion disclosed in the embodiment of the present application is in a contracted state;

[0019] Figure 5 For this application Figure 4 The enlarged schematic diagram of point A in the middle;

[0020] Figure 6 A cross-sectional view of a first pipe section disclosed in an embodiment of the present application;

[0021] Figure 7 For this application Figure 6 The enlarged schematic diagram of point B in the middle;

[0022] Figure 8 A structural diagram of the expandable portion disclosed in an embodiment of the present application;

[0023] Fig. 9 A cross-sectional view of the sheath tube assembly after the skin is hidden when the expandable portion disclosed in the embodiment of the present application is in an expanded state;

[0024] Fig.10 For this application Fig. 9 The enlarged schematic diagram of the center C;

[0025] Fig.11 It is a partial structural schematic diagram of the sheath tube assembly when the expandable portion disclosed in the embodiment of the present application is in a contracted state;

[0026] Fig.12 It is a partial structural schematic diagram of a sheath tube assembly when the expandable portion disclosed in another embodiment of the present application is in an expanded state;

[0027] Fig.13 For this application Fig.12 The enlarged schematic diagram of point D in the middle;

[0028] Fig.14 A front view of the first pipe section disclosed in the embodiment of the present application;

[0029] Fig.15 A schematic diagram of the cooperation between the first pipe segment and the passive bending segment disclosed in the embodiment of the present application;

[0030] Fig.16 This is a schematic diagram of the process of the sheath tube assembly disclosed in an embodiment of the present application cooperating with the active bending section to extract the material to be aspirated.

[0031] Description of reference numerals:

[0032] 100, first pipe section; 110, sleeve portion; 111, deformation notch; 200, second pipe section; 210, expandable portion; 211, main body; 2111, deformable body; 2112, elastic bracket; 212, mounting ring; 300, retaining member; 400, transmission rod; 500, protrusion; 501, abutment area; 510, first protrusion; 520, second protrusion; 600, skin; 700, insertion portion; 710, active bending section; 720, passive bending section. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0035] The guide sheath and sheath tube assembly provided in the embodiments of the present application are described in detail below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0036] In each embodiment of the present application, "proximal end" and "distal end" refer to the position of the introducer sheath and its components relative to the user in the use environment, wherein the end closer to the user is designated as the "proximal end" and the end farther from the user is designated as the "distal end".

[0037] like Figure 1As shown, during the operation in which the insertion portion 700 and the sheath are used together to remove stones and wait for the suction material, there is a suction gap between the endoscope insertion portion 700 and the inner wall of the sheath, so that the stones are discharged from the suction gap; of course, in order to facilitate the doctor to obtain the location of the stones, especially in the operation of kidney stone removal, the endoscope needs to be inserted into the renal calyx through the natural cavity or percutaneous kidney to remove stones in various areas of the renal calyx. Therefore, in order to avoid causing great trauma to the patient's kidneys, most endoscopes have a controllable bending function. Therefore, in order to adapt to the bending of the active bending section 710 of the endoscope insertion portion 700, the distal end of the sheath adapted thereto in the prior art also has the ability of passive bending, that is, the active bending section 710 of the endoscope can drive the distal end of the sheath to bend during the bending process.

[0038] The inventors discovered that, in actual surgical procedures, when the active bending segment 710 drives the sheath tube to be in a bent state, different parts of the active bending segment 710 will press against specific positions of the sheath tube. Therefore, in the extension direction of the active bending segment 710, the maximum distances between the various parts of the curved active bending segment 710 in its own extension direction and the inner wall of the curved sheath tube are unevenly distributed. In other words, the maximum distances between the various parts of the curved active bending segment 710 in its own extension direction and the inner wall of the curved sheath tube are constantly changing. Therefore, in the process of aspirating stones, stones with a size equal to or slightly larger than the minimum value of the maximum distances may be blocked between the curved sheath tube and the curved active bending segment 710, resulting in poor stone removal.

[0039] Here, the maximum distance between each part of the curved active bending section 710 in its own extension direction and the inner wall of the curved sheath tube is explained. Figure 1 In views a to g, since the diameter of the active bending segment 710 is smaller than the diameter of the sheath tube, there must be a gap between the curved active bending segment 710 and the curved sheath tube, and the gap is arranged around the curved active bending segment 710. Therefore, the distances between various circumferential regions of a part of the curved active bending segment 710 in its own extension direction and the inner wall of the sheath tube are not equal, and the maximum value of the distances between various circumferential regions of this part of the curved active bending segment 710 and the sheath tube is: the maximum distance between this part of the curved active bending segment 710 and the curved sheath tube.

[0040] like Figures 2 to 16As shown, the embodiment of the present application discloses a sheath assembly, which is applied to a guide sheath, including a sheath, a retainer 300 and a drive mechanism, wherein the sheath includes a first tube segment 100 and a second tube segment 200 sequentially distributed in a direction extending from its proximal end to its distal end, that is, the distal end of the first tube segment 100 is connected to the proximal end of the second tube segment 200. Specifically, the proximal end of the sheath can be fixedly connected to the distal end of the operating handle of the guide sheath.

[0041] The first tube segment 100 is slidably connected to the second tube segment 200. Here, the first tube segment 100 can be connected to the inside or outside of the second tube segment 200. One of the distal end of the first tube segment 100 and the proximal end of the second tube segment 200 is provided with an expandable portion 210. One end of the retaining member 300 is connected to the second tube segment 200, and the other end is connected to the first tube segment 100 or the operating handle of the guide sheath to fix the length of the sheath.

[0042] It should be noted that, since the expandable portion 210 can switch between the contracted state and the expanded state, and the length of the expandable portion 210 itself will change during the switching process, for example, when the expandable portion 210 switches from the contracted state to the expanded state, the expandable portion 210 will expand radially, but its length will shorten. Therefore, when the connection relationship between the first tube segment 100 and the second tube segment 200 is a fixed connection, the change in the length of the expandable portion 210 will cause the length of the sheath to change, which will obviously cause the sheath to approach or move away from the object to be sucked, thereby causing the relative position between the distal opening of the second tube segment 200 and the object to be sucked to change.

[0043] After adopting the structure of the embodiment of the present application, the expandable part 210 is arranged on the first tube segment 100 or the second tube segment 200, and the retaining member 300 can fix the length of the sheath tube. However, the change in the length of the expandable part 210 will change the length of the first tube segment 100 or the second tube segment 200, while the length of the sheath tube will not change. Therefore, in order to compensate for the change in the length of the first tube segment 100 or the second tube segment 200, the embodiment of the present application slides the first tube segment 100 and the second tube segment 200 together, thereby compensating the change in the length of the first tube segment 100 or the second tube segment 200 as the relative sliding between the first tube segment 100 and the second tube segment 200 to ensure that the length of the sheath tube does not change.

[0044] Optionally, the first pipe segment 100 and the second pipe segment 200 are slidably sealed, for example, a sealing structure (such as an O-ring) can be provided between the first pipe segment 100 and the second pipe segment 200 to prevent the suctioned material from leaking out of the sheath tube from the slidably fitted portion between the first pipe segment 100 and the second pipe segment 200. The sheath tube assembly may further include a skin 600, which covers the outside of the sheath tube.

[0045] The expandable portion 210 can switch between an expanded state and a contracted state. Specifically, the second tube segment 200 close to its distal opening has the ability to bend passively, that is, the active bending segment 710 can drive the second tube segment 200 close to its distal opening to bend. In addition, the second tube segment 200 far from its distal opening may also have the ability to bend passively or may not have the ability to bend passively, and this application does not limit this.

[0046] When the expandable portion 210 is in an expanded state, at least a portion of the expandable portion 210 radially protrudes outward from other portions of the sheath, that is, along the direction extending from the inside of the expandable portion 210 to the outside, at least a portion of the expandable portion 210 protrudes outward from other portions of the sheath, and the flow area of ​​the first lumen of the expandable portion 210 is greater than the flow area of ​​the second lumen of other portions of the sheath. Specifically, the other portion of the sheath refers to the portion of the sheath outside the expandable portion 210, and the other portion of the sheath may be a pipe section of equal diameter; or the other portion of the sheath may also be a pipe section of unequal diameter, in which case at least a portion of the expandable portion 210 radially protrudes outward from the point where the diameter of the pipe section of unequal diameter is the largest.

[0047] Optionally, when the expandable portion 210 is in an expanded state, all regions of the expandable portion 210 along its own circumference expand outwardly, and all parts of the expandable portion 210 along its own circumference protrude radially outward from other parts of the sheath; or, when the expandable portion 210 is in an expanded state, a partial region of the expandable portion 210 along its own circumference expands outwardly, a part of the expandable portion 210 along its own circumference protrudes radially outward from other parts of the sheath, and another partial region of the expandable portion 210 along its own circumference may be flush with other parts of the sheath.

[0048] When the expandable portion 210 is in a contracted state, at least a portion of the expandable portion 210 is flush with or radially convex to other portions of the sheath, that is, along the direction extending from the outside to the inside of the expandable portion 210, at least a portion of the expandable portion 210 protrudes from other portions of the sheath, and the flow area of ​​the first inner cavity is less than or equal to the flow area of ​​the second inner cavity. Specifically, when the expandable portion 210 is in a contracted state, all portions of the expandable portion 210 may be flush with or radially convex to other portions of the sheath, or a portion of the expandable portion 210 may be flush with other portions of the sheath, and another portion may radially convex to other portions of the sheath.

[0049] The driving mechanism can switch the expandable portion 210 from the contracted state to the expanded state.

[0050] In the present application, the expandable portion 210 can switch between a contracted state and an expanded state. Before the sheath is inserted into the human body, the expandable portion 210 can be switched to the contracted state. At this time, at least a portion of the expandable portion 210 is flush with or radially convex to other portions of the sheath, that is, all portions of the expandable portion 210 do not radially convex to other portions of the sheath, thereby facilitating the insertion of the sheath into the human body.

[0051] When the sheath is inserted into the human body and the stone to be aspirated needs to be aspirated, the drive mechanism can be used to switch the expandable portion 210 from the contracted state to the expanded state, and then the insertion portion 700 of the endoscope can be inserted into the sheath, and the active bending section 710 of the insertion portion 700 can drive at least part of the tube section of the sheath close to its own distal opening to bend. When the active bending section 710 is bent, different parts of the active bending section 710 will press against specific positions of the sheath, so that the parts of the bent active bending section 710 in the direction of its own extension are respectively aligned with the sheath tube driven by the active bending section 710 The maximum distance between the inner walls of the curved tube segments is constantly changing, and after the expandable portion 210 of the present application is in an expanded state, the size of the first inner cavity of the expandable portion 210 is larger than the size of the second inner cavity of the other parts of the sheath. In this way, the expandable portion 210 can be used to increase the minimum value of each maximum distance, so that the minimum value of each maximum distance is larger than the size of the target object in the object to be sucked. In this way, the target object can smoothly pass through the gap between the curved active bending segment 710 and the inner wall of the tube segment of the sheath bent by the active bending segment 710, thereby solving the problem of unsmooth discharge of the object to be sucked.

[0052] It should be noted that the target object refers to an object to be aspirated, such as a stone, whose size is equal to or slightly larger than the minimum value of the maximum distance between each part of the active bending section 710 of the prior art in its own extension direction and the sheath tube. Here, the size of the target object is equal to or slightly larger than half of the difference in tube diameter between the sheath tube and the active bending section 710 of the prior art.

[0053] Furthermore, the present application also fixes the length of the sheath by means of the retaining member 300, thereby preventing the length of the sheath from changing when the expandable portion 210 expands or contracts, thereby preventing the relative position between the distal opening of the second tube segment 200 and the object to be aspirated from changing, thereby eliminating the need to adjust the position of the sheath and the endoscope to direct the distal opening of the sheath toward the object to be aspirated, thereby simplifying the operating procedure.

[0054] The embodiments of using the expandable portion 210 of the present application to make the minimum value of each maximum distance larger than the size of the target object in the object to be sucked include the following two:

[0055] 1. After the insertion portion 700 of the endoscope is inserted into the sheath and the active bending section 710 drives the sheath to bend, the expandable portion 210 in the expanded state corresponds to the minimum value of each maximum distance of the sheath in the prior art, that is, after the active bending section 710 is inserted into the sheath and drives the sheath to bend, the minimum value of each maximum distance is greater than the size of the target object, so that the target object can smoothly pass through the gap between the bent active bending section 710 and the inner wall of the tube section of the sheath bent by the active bending section 710, thereby solving the problem of unsmooth discharge of stones while waiting for suction.

[0056] 2. Please refer to Fig.16 After the insertion portion 700 of the endoscope is inserted into the sheath and the active bending section 710 drives the sheath to bend, the expandable portion 210 in the expanded state does not correspond to the minimum value of each maximum distance of the sheath in the prior art. For example, the expandable portion 210 is located proximal to the minimum value of each maximum distance of the sheath. At this time, it is only necessary to pull the active bending section 710 to move the active bending section 710 toward the direction close to the operating handle until a part of the bent active bending section 710 enters the expandable portion 210, so that the minimum value of each maximum distance is greater than the size of the target object by using the expandable portion 210, thereby introducing the target object stuck between the bent sheath and the bent active bending section 710 into the expandable portion 210, so as to solve the problem of the target object being stuck between the bent sheath and the bent active bending section 710.

[0057] Please note that Fig.16 In the first figure, there is also a narrow space between the insertion part 700 and the section of the sheath tube located near the expandable part 210. However, since the insertion part 700 does not cause the section of the sheath tube located near the expandable part 210 to bend, the section of the sheath tube located near the expandable part 210 and the portion of the insertion part 700 located in the section both remain in a relatively straight state, and the portion of the insertion part 700 located in the section has better mobility in the sheath tube. When the target enters the above-mentioned narrow space, the target can push the insertion part 700 to increase the narrow space and prevent the target from getting stuck.

[0058] In some embodiments, the expandable portion 210 includes a deformable body 2111 and a deformation memory metal stent, the deformable body 2111 has a first inner cavity, the deformation memory metal stent is connected to the deformable body 2111, and the driving mechanism includes a conductive wire, which is electrically connected to the deformation memory metal stent. When the deformation memory metal stent is not energized through the conductive wire, the deformation memory metal stent is in a contracted state, so that the expandable portion 210 is in a contracted state; when the deformation memory metal stent is energized through the conductive wire, the deformation memory metal stent is in an expanded state, so that the expandable portion 210 is in an expanded state.

[0059] In other embodiments, the expandable portion 210 includes a flexible deformable body, and the driving mechanism includes a transmission rod 400, the transmission rod 400 is connected to the distal end of the flexible deformable body, and the transmission rod 400 can move between the third position and the fourth position to make the flexible deformable body in an expanded state or a contracted state. For example, the direction extending from the third position to the fourth position can be the direction extending from the proximal end to the distal end of the sheath. At this time, when the transmission rod 400 is located in the third position, the distance between the distal end and the proximal end of the flexible deformable body is small, and the transmission rod 400 is in an expanded state; in the process of the transmission rod 400 moving from the third position to the fourth position, the transmission rod 400 drives the distal end of the flexible deformable body away from the proximal end of the flexible deformable body, so that the distance between the distal end and the proximal end of the flexible deformable body becomes larger, thereby switching the flexible deformable body from the expanded state to the contracted state. Of course, the direction extending from the fourth position to the third position can also be the direction extending from the proximal end to the distal end of the sheath.

[0060] In some other embodiments, the expandable portion 210 is an elastic deformable body, and the expandable portion 210 is in an expanded state in a natural state. The driving structure includes a constraint tube, and the constraint tube is slidably sleeved outside the sheath tube. The staggered setting here refers to the constraint tube and the expandable portion 210 being staggered in the radial direction of the constraint tube. When the constraint tube is sleeved outside the expandable portion 210, the expandable portion 210 undergoes elastic contraction to be in a contracted state; when the constraint tube and the expandable portion 210 are staggered, the expandable portion 210 restores elastic deformation to be in an expanded state. It should be noted that in this embodiment, the retainer 300 is a structural member with a certain rigidity and a certain bending performance, such as a slender rod, a steel wire, etc. At this time, the retainer 300 can prevent the distal end of the second pipe segment 200 from moving in a direction close to and / or away from the first pipe segment 100.

[0061] See also Figures 3 to 5 as well as Figure 8 In an optional embodiment, the expandable portion 210 is an elastic deformable body, and the expandable portion 210 is in a contracted state in a natural state. Optionally, the elastic deformable body can be made of an elastic material, such as rubber, silicone, etc., and the elastic deformable body has a first inner cavity; or, the elastic deformable body includes a deformable body 2111 and an elastic support 2112, and the deformable body 2111 has a first inner cavity, and the elastic support 2112 is connected to the deformable body 2111.

[0062] In this embodiment, the expandable portion 210 is in a contracted state in a natural state, and is not in an expanded state. Therefore, before the sheath is inserted into the human body, there is no need to use a tube body that limits the expandable portion 210 to be sleeved outside the expandable portion 210, thereby forcing the expandable portion 210 to be in a contracted state. This can reduce the outer diameter of the sheath assembly to facilitate the sheath assembly to enter the human body.

[0063] In some embodiments, the expandable portion 210 may be disposed at the distal end of the first tube segment 100. In this case, one end of the retaining member 300 may be connected to any portion of the second tube segment 200. The driving mechanism includes a traction member capable of transmitting pulling force. One end of the traction member is connected to the distal end of the expandable portion 210 or to a portion of the first tube segment 100 located distal to the expandable portion 210. The retaining member 300 here has a certain rigidity, which can constrain the second tube segment 200 to move in the second direction (the direction of movement from the distal end to the proximal end of the sheath) and in the opposite direction. During the process of pulling the traction member, the traction member can drive the distal end of the expandable portion 210 to move along the second direction, so that the length of the expandable portion 210 is compressed to produce radial expansion. At this time, the retaining member 300 can limit the second tube segment 200 from moving along the second direction; after releasing the traction member, the expandable portion 210 restores its elastic deformation, so that the length of the expandable portion 210 is extended to restore to a contracted state. At this time, the retaining member 300 can limit the second tube segment 200 from moving in the opposite direction of the second direction to keep the length of the sheath unchanged.

[0064] See also Figures 3 to 12 In an optional embodiment, the expandable portion 210 is disposed on the second tube segment 200, one end of the retaining member 300 is connected to the distal end of the expandable portion 210 or the portion of the second tube segment 200 located on the distal side of the expandable portion 210, and the driving mechanism includes a transmission rod 400 capable of transmitting thrust, wherein the transmission rod 400 is a structural member having a certain rigidity and a certain bending performance, such as a slender rod, a steel wire, etc. The transmission rod 400 is connected to the proximal end of the expandable portion 210 or the portion of the second tube segment 200 located on the proximal side of the expandable portion 210, and when the transmission rod 400 is subjected to thrust, the expandable portion 210 can switch from a contracted state to an expanded state.

[0065] The specific operation process of this embodiment is as follows: the transmission rod 400 is pushed, and the transmission rod 400 can drive the proximal end of the expandable part 210 to move in the opposite direction of the second direction, so that the proximal end of the expandable part 210 gradually approaches the distal end of the expandable part 210, so that the length of the expandable part 210 is compressed to produce radial expansion. During this process, the transmission rod 400 applies a force in the opposite direction of the second direction to the second tube segment 200, and the retaining member 300 can resist the force to prevent the second tube segment 200 from moving in the opposite direction of the second direction. After releasing the transmission rod 400, the expandable portion 210 will restore its elastic deformation, and the proximal end of the expandable portion 210 will gradually move away from the distal end of the expandable portion 210, so that the expandable portion 210 returns to its original length to switch to a contracted state. During this process, the expandable portion 210 will not be subjected to the force in the second direction, which not only reduces the risk of changes in the position maintained by the second tube segment 200, but also enables the retaining member 300 to not have the function of resisting the force in the second direction. For example, the retaining member 300 may be a retaining rope, which may not have a certain rigidity, thereby simplifying the structure of the retaining member 300. Of course, the retaining member 300 of this embodiment may also have a certain rigidity, and the present application does not limit this.

[0066] See also Fig.11 In an optional embodiment, at least part of the transmission rod 400 is slidably sleeved outside the retaining member 300. Optionally, the transmission rod 400 may be disposed inside or outside the sheath, which is not limited in the present application.

[0067] In this embodiment, a penetration space is provided in the transmission rod 400, and at least a part of the retaining member 300 is penetrated in the penetration space. Since both ends of the retaining member 300 are fixed ends, that is, both ends of the retaining member 300 are connected to corresponding parts, the retaining member 300 has a certain ability to maintain its own shape, and it is not easy to deform radially under the action of external force. In this way, in the process of pushing the transmission rod 400, the ability of the retaining member 300 to maintain its own shape can be used to limit the bending deformation of the transmission rod 400 when it is pushed, so that the transmission rod 400 can stably transmit the thrust, so that the expandable part 210 can be stably switched to the expanded state.

[0068] This embodiment is described by taking the retaining member 300 as a retaining rope as an example. Before the transmission rod 400 is pushed, the retaining rope is in a tensioned state, and the tension of the retaining rope is a first preset value. When the transmission rod 400 is pushed, the transmission rod 400 applies a force in the opposite direction of the second direction to the second pipe section 200 and the retaining rope connected to the second pipe section 200, thereby further tensioning the retaining rope. At this time, the tension of the retaining rope is a second preset value, which is greater than the first preset value. It can be seen that when the retaining member 300 is a retaining rope, the tension of the retaining rope can be gradually increased in the process of pushing the transmission rod 400 to move, so that the ability of the retaining rope to maintain its own shape is further enhanced, and the risk of bending and deformation of the retaining member 300 will be further reduced. That is to say, when the expandable portion 210 is in a contracted state, the stiffness of the whole composed of the retaining member 300 and the transmission rod 400 is a first stiffness; when the expandable portion 210 is in an expanded state, the stiffness of the whole composed of the retaining member 300 and the transmission rod 400 is a second stiffness, and the second stiffness is greater than the first stiffness. In this way, when the sheath is inserted into the human body, the ability of the whole composed of the retaining member 300 and the transmission rod 400 to follow the bending is stronger, so it is easier to insert the sheath assembly into the human body.

[0069] Of course, the transmission rod 400 and the retaining member 300 may not be arranged in a sleeve relationship, and the two may be arranged at an interval. In this case, the transmission rod 400 can have greater rigidity to prevent it from bending and deformation, so as to stably transmit the thrust.

[0070] See also Figure 11 to Figure 12 In an optional embodiment, the joint between the retaining member 300 and the second tube segment 200 is a first joint, and when the expandable portion 210 is in an expanded state, the transmission rod 400 is in upper limit contact with the first joint in a direction extending from the proximal end to the distal end of the sheath.

[0071] In this embodiment, one end of the retainer 300 is connected to the second tube section 200, and the connection here can be welding, bonding, etc. When the expandable part 210 is in an expanded state, the transmission rod 400 and the first joint are in upper limit contact in the direction extending from the proximal end to the distal end of the sheath, so that the transmission rod 400 can be prevented from moving too much in the opposite direction of the second direction, thereby preventing the expandable part 210 from being axially compressed too much and affecting the elastic performance of the expandable part 210, and preventing the proximal end of the expandable part 210 from moving too much in the opposite direction of the second direction following the transmission rod 400 and being disengaged from the first tube section 100. In addition, in this embodiment, the joint between the retainer 300 and the second tube section 200 is used to limit the transmission rod 400, so there is no need to add other additional limiting structures to limit the transmission rod 400 or the proximal end of the expandable part 210, which can simplify the structure of the sheath assembly.

[0072] See also Figures 4 to 5In an optional embodiment, when the expandable portion 210 is in a contracted state, a portion of the expandable portion 210 is sleeved within the first tube segment 100 or the second tube segment 200, that is, when the expandable portion 210 is arranged in the first tube segment 100, the distal end of the expandable portion 210 is sleeved within the second tube segment 200; when the expandable portion 210 is arranged in the second tube segment 200, the proximal end of the expandable portion 210 is sleeved within the first tube segment 100.

[0073] In this embodiment, when the expandable portion 210 is in a contracted state, a portion of the expandable portion 210 is sleeved within the first tube segment 100 or the second tube segment 200, so that the first tube segment 100 or the second tube segment 200 can be used to limit the radial expansion of the portion of the expandable portion 210, so that when the sheath assembly is inserted into the human body, even if the human tissue exerts a reaction force along the second direction on the sheath, the first tube segment 100 or the second tube segment 200 can prevent the expandable portion 210 from expanding under the force, that is, the structure of this embodiment can prevent the expandable portion 210 from expanding when it is necessary to maintain a contracted state, so as to facilitate the insertion of the sheath assembly into the human body. It should be noted that this embodiment can be implemented independently of the next embodiment. Of course, when the expandable portion 210 is in a contracted state, all parts of the expandable portion 210 may be located outside the first tube segment 100 or the second tube segment 200, that is, there is no part of the expandable portion 210 that is sleeved inside the first tube segment 100 or the second tube segment 200, and the present application does not impose any restrictions on this.

[0074] Since a portion of the expandable portion 210 is sleeved in the first tube segment 100 or the second tube segment 200 when the expandable portion 210 is in a contracted state, when the portion of the expandable portion 210 sleeved in the first tube segment 100 or the second tube segment 200 gradually disengages from the first tube segment 100 or the second tube segment 200, the expandable portion 210 expands outwards. At this time, the portion of the expandable portion 210 outside the first tube segment 100 or the second tube segment 200 expands outwards. The first pipe segment 100 or the second pipe segment 200 has a certain rigidity, so the part of the expandable portion 210 located within the first pipe segment 100 or the second pipe segment 200 will still be constrained to be in a contracted state, which will cause the expandable portion 210 to suddenly switch from an expanded state to a contracted state at the pipe mouth of the first pipe segment 100 or the second pipe segment 200, thereby generating internal stress at the position of the expandable portion 210 corresponding to the pipe mouth of the first pipe segment 100 or the second pipe segment 200 and damaging the expandable portion 210.

[0075] In order to prevent the expandable portion 210 from being damaged by internal stress, in a further embodiment, one of the first tube segment 100 and the second tube segment 200 that can be sleeved outside the expandable portion 210 is provided with a deformation notch 111, the deformation notch 111 passes through the side wall of the first tube segment 100 or the second tube segment 200, and the deformation notch 111 extends to the end surface of the first tube segment 100 or the second tube segment 200 close to the expandable portion 210. Optionally, the number of the deformation notches 111 here can be one or more, and the multiple deformation notches 111 are distributed at intervals along the circumference of the sheath.

[0076] In this embodiment, one of the first pipe segment 100 and the second pipe segment 200 that can be sleeved outside the expandable part 210 is provided with a deformation notch 111, which can reduce the stiffness of the first pipe segment 100 or the second pipe segment 200. In this way, when the portion of the expandable part 210 sleeved inside the first pipe segment 100 or the second pipe segment 200 gradually disengages from the first pipe segment 100 or the second pipe segment 200, the deformation notch 111 will reduce the stiffness of the first pipe segment 100 or the second pipe segment 200, so the ability of the first pipe segment 100 or the second pipe segment 200 to limit the expandable part 210 from being in a contracted state becomes worse, and the portion of the expandable part 210 located in the first pipe segment 100 or the second pipe segment 200 will expand slightly outward, thereby preventing the expandable part 210 from suddenly switching from an expanded state to a contracted state at the pipe mouth of the first pipe segment 100 or the second pipe segment 200, thereby reducing the risk of damage to the expandable part 210. Of course, the one of the first tube section 100 and the second tube section 200 that can be sleeved outside the expandable portion 210 may not be provided with the deformation notch 111, and the present application does not limit this.

[0077] Optionally, one of the first tube segment 100 and the second tube segment 200 that can be sleeved outside the expandable portion 210 includes a sleeve portion 110. When the expandable portion 210 is in a contracted state, a portion of the expandable portion 210 is sleeved inside the sleeve portion 110, and the sleeve portion 110 is provided with the above-mentioned deformation notch 111. Taking the sleeve portion 110 provided at the distal end of the first tube segment 100 as an example, the inner hole size of the sleeve portion 110 is larger than the inner hole size of the portion of the first tube segment 100 located outside the sleeve portion 110, thereby forming a step at the proximal end of the sleeve portion 110, and the step here can stop and limit the second tube segment 200 in the direction extending from the distal end to the proximal end of the sheath.

[0078] Optionally, the expandable portion 210 includes a main body 211 and a mounting ring 212. The main body 211 is capable of radial expansion. The main body 211 here may include a deformable body 2111 and an elastic bracket 2112. For example, the main body 211 is a coated bracket. Mounting rings 212 are provided at both ends of the main body 211, and the mounting rings 212 are slidably matched with the sleeve portion 110.

[0079] See also Figure 4 , Figure 5 and Fig.11 In an optional embodiment, the distal end of the second tube segment 200 can bend following the active bending segment 710 of the endoscope. The endoscope here can be a bronchoscope, a pyeloscope, an esophagoscope, a gastroscope, a colonoscope, an otoscope, a rhinoscope, a stomatoscope, a laryngoscope, a colposcope, a laparoscope, an arthroscope, etc. The embodiment of the present application does not specifically limit the type of endoscope. The plane in which the bending direction of the second tube segment 200 is located is the first plane, the axis of the sheath is located in the first plane, and the retaining member 300 is arranged in the sheath and is located on one side of the first plane.

[0080] like Figure 1 As shown, the flow channel with the best permeability formed between the active bending section 710 and the sheath is located on both sides of the sheath along its own bending direction, and in this embodiment, the retainer 300 is arranged on one side of the first plane, that is, the retainer 300 is arranged on the side of the sheath adjacent to the flow channel with the best permeability, that is, the retainer 300 is not arranged in the flow channel with the best permeability, which can avoid the retainer 300 occupying the space in the flow channel with the best permeability, thereby improving the permeability of the object to be sucked in the sheath. Of course, the retainer 300 can also be arranged on one side of the sheath along its own bending direction.

[0081] and / or, see Figure 5 In an optional embodiment, when the expandable portion 210 is in a contracted state, the second tube segment 200 is in limited contact with the first tube segment 100 in a direction extending from the distal end to the proximal end of the sheath, thereby preventing the second tube segment 200 from sliding relative to the first tube segment 100 when the sheath assembly is inserted into the human body.

[0082] Optionally, one of the first tube segment 100 and the second tube segment 200 is provided with an abutment portion, and the other is provided with a stop portion, and the abutment portion and the stop portion are limitedly matched in the direction extending from the distal end to the proximal end of the sheath tube. The abutment portion here can be the edge of the tube mouth of the first tube segment 100 or the second tube segment 200.

[0083] And / or, in an optional embodiment, when the expandable portion 210 is in an expanded state, the second tube segment 200 and the first tube segment 100 are in position-limiting contact in the direction extending from the proximal end to the distal end of the sheath, so that the second tube segment 200 can be prevented from separating from the first tube segment 100. Optionally, one of the first tube segment 100 and the second tube segment 200 is provided with a first position-limiting protrusion, and the other is provided with a second position-limiting protrusion, and the first position-limiting protrusion and the second position-limiting protrusion are in position-limiting cooperation in the direction extending from the proximal end to the distal end of the sheath.

[0084] and / or, see Figure 6 , Figure 7 and Fig.14Although the portion of the insertion portion 700 located in the first tube segment 100 (the passive bending segment 720) has good mobility in the sheath, the target object can push the portion of the insertion portion 700 located in the first tube segment 100 to prevent the target object from getting stuck, in order to further prevent the target object from getting stuck, in an optional embodiment, the first tube segment 100 has a accommodating space for accommodating the passive bending segment 720 of the endoscope, the axis of the accommodating space is located on a first side of the axis of the first tube segment 100, and the other side of the axis of the first tube segment 100 is a second side opposite to the first side, and the first tube segment 100 is provided with a force-applying structure, which can apply a first direction of force to the passive bending segment 720 located in the accommodating space, wherein the first direction ( Fig.14 The direction indicated by the y arrow line is the direction extending from the second side to the first side.

[0085] In this embodiment, the first pipe section 100 has a storage space, and the axis of the storage space is located on the first side of the axis of the first pipe section 100, that is, the storage space is not in the middle of the first pipe section 100, which can make the space on the side of the storage space in the first pipe section 100 in the opposite direction of the first direction have a larger size, and this space is the flow space for the object to be sucked to pass through. It can be seen that after the passive bending section 720 is arranged in the storage space, the flow space on the side of the passive bending section 720 can have a larger size, so as to achieve the purpose of anti-blocking. In addition, in this embodiment, a force-applying structure is provided on the first pipe section 100, and the force-applying structure can apply a force in the first direction to the passive bending section 720, so that the passive bending section 720 remains in the storage space, preventing the passive bending section 720 from moving in the opposite direction of the first direction to occupy part of the flow space on the side of the storage space, thereby ensuring that the passive bending section 720 is biased in the first pipe section 100, reserving a larger size for the flow space, and preventing blockage.

[0086] In an optional embodiment, the force-applying structure includes a protrusion 500 radially protruding from the inner wall of the first pipe segment 100. The protrusion 500 here has a certain rigidity, so the protrusion 500 is not easily deformed during the bending of the first pipe segment 100. The protrusion 500 is connected to the first pipe segment 100, and the protrusion 500 radially extends to the accommodating space so that the protrusion 500 contacts the passive bending segment 720 located in the accommodating space, and the passive bending segment 720 cooperates with the protrusion 500 in the upper limit position in the opposite direction of the first direction.

[0087] The specific working process of this embodiment is as follows: insert the insertion part 700 into the sheath tube, and make the passive bending section 720 located in the accommodation space, at this time, the protrusion 500 contacts the passive bending section 720, and the passive bending section 720 cooperates with the protrusion 500 in the upper limit position in the opposite direction of the first direction. When the passive bending section 720 has a tendency to move in the opposite direction of the first direction, the protrusion 500 will stop and limit the passive bending section 720, and apply a force in the first direction to the passive bending section 720 to limit the passive bending section 720 from moving in the opposite direction of the first direction, so that the passive bending section 720 remains located in the accommodation space to prevent blockage. In addition, the protrusion 500 of this embodiment also has a certain rigidity, which can improve the stability of the protrusion 500 stopping and limiting the passive bending section 720, so as to improve the anti-blockage effect.

[0088] In other embodiments, the force-applying structure may also be a magnetic member. In this case, the passive bending section 720 is magnetic. The passive bending section 720 is kept in the accommodation space by applying an adsorption force along the first direction to the passive bending section 720 through the magnetic member. The magnetic member may be a magnet or an energized coil.

[0089] In some other embodiments, the force-applying structure may also be an elastic sac having a fluid port, through which fluid, such as gas or liquid, can be injected into the elastic sac to fill the elastic sac. When the elastic sac is in the filled state, the elastic sac extends to the accommodating space to make the elastic sac contact with the passive bending segment 720, and make the passive bending segment 720 contact with the upper limit position of the protrusion 500 in the opposite direction of the first direction.

[0090] See also Figure 14 to Figure 15 In an optional embodiment, the number of the protrusions 500 may be only one, or the protrusions 500 include a first protrusion 510 and a second protrusion 520, wherein the structures of the first protrusion 510 and the second protrusion 520 may be the same, and the first protrusion 510 and the second protrusion 520 are respectively located on both sides of the first pipe section 100 along the second direction. Fig.14 The direction indicated by the x-arrow line in the figure is respectively perpendicular to the first direction and the axial direction of the first pipe segment 100.

[0091] In this embodiment, the protrusion 500 includes a first protrusion 510 and a second protrusion 520, and the first protrusion 510 and the second protrusion 520 both extend to the accommodation space, that is, the first protrusion 510 and the second protrusion 520 can both limit the passive bending section 720, which can improve the limiting stability of the protrusion 500 on the passive bending section 720. It should be noted that this embodiment can be implemented independently of the next embodiment.

[0092] For further examples, see Fig.15The first protrusion 510 and the second protrusion 520 both include a contact area 501 that can contact the passive bending section 720. The contact area 501 of the first protrusion 510 and the contact area 501 of the second protrusion 520 are both located on the side of the axis of the accommodating space facing the second side. Along the second direction, the contact area 501 of the first protrusion 510 and the contact area 501 of the second protrusion 520 are staggered.

[0093] In this embodiment, the abutment between the abutment area 501 of the first convex portion 510 and the passive bending section 720 is the first abutment, and the abutment between the abutment area 501 of the second convex portion 520 and the passive bending section 720 is the second abutment. Since the abutment area 501 of the first convex portion 510 and the abutment area 501 of the second convex portion 520 are staggered along the second direction, the first abutment and the second abutment are also staggered along the second direction. Compared with the embodiment in which the first abutment and the second abutment are relatively arranged, this embodiment can increase the connection distance between the first abutment and the second abutment, thereby increasing the diameter of the passive bending section 720 that can be limited by the convex portion 500, so that the sheath tube assembly of this embodiment is adapted to the insertion portion 700 of a larger size. Of course, the abutment area 501 of the first convex portion 510 and the abutment area 501 of the second convex portion 520 can also be relatively arranged in the second direction, and there is no staggered part between the two at this time, and this application does not limit this.

[0094] The present application also discloses a guide sheath, including the sheath tube assembly described in any of the above embodiments, so that the guide sheath has the beneficial effects of the above sheath tube assembly, which will not be repeated here. Optionally, the guide sheath may also include an operating handle, the distal end of the operating handle is connected to the proximal end of the sheath tube. The guide sheath here can be used in conjunction with a dilator, and the dilator makes it easier to introduce the guide sheath into the human body.

[0095] The above embodiments of the present application focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here. The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present application, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present application and the claims, all of which are within the protection of the present application.

Claims

1. A sheath tube assembly, applied to a guide sheath, characterized in that: The invention comprises a sheath tube, a retaining member (300) and a driving mechanism, wherein the sheath tube can be movably sleeved on the outside of an active bending section (710) of an endoscope, and the active bending section (710) can drive at least a portion of the tube section of the sheath tube close to its own distal opening to bend, and the maximum distance between each part of the bent active bending section (710) in the direction of its own extension and the inner wall of the tube section of the sheath tube bent by the active bending section (710) changes continuously, and the sheath tube comprises a first tube section (100) and a second tube section (200) which are sequentially distributed in the direction extending from its own proximal end to its distal end; The first tube segment (100) is slidably sleeved with the second tube segment (200); one of the distal end of the first tube segment (100) and the proximal end of the second tube segment (200) is provided with an expandable portion (210); one end of the retaining member (300) is connected to the second tube segment (200), and the other end is connected to the first tube segment (100) or an operating handle of the guide sheath to fix the length of the sheath tube; The expandable portion (210) is switchable between an expanded state and a contracted state. When the expandable portion (210) is in the expanded state, at least a portion of the expandable portion (210) radially protrudes outward from other portions of the sheath tube, and a flow area of ​​a first inner cavity of the expandable portion (210) is larger than a flow area of ​​a second inner cavity of other portions of the sheath tube, so that a minimum value of each maximum distance is larger than a size of a target object in an object to be aspirated. When the expandable portion (210) is in the contracted state, at least a portion of the expandable portion (210) is flush with or radially protrudes inward from other portions of the sheath tube, and a flow area of ​​the first inner cavity is smaller than or equal to a flow area of ​​the second inner cavity. The driving mechanism is capable of switching the expandable portion (210) from the contracted state to the expanded state.

2. The sheath tube assembly according to claim 1, characterized in that: The expandable portion (210) is an elastic deformable body, and the expandable portion (210) is in the contracted state in a natural state.

3. The sheath tube assembly according to claim 2, characterized in that: The expandable portion (210) is provided on the second tube section (200), and one end of the retaining member (300) is connected to the distal end of the expandable portion (210) or a portion of the second tube section (200) located on the distal side of the expandable portion (210); The driving mechanism comprises a transmission rod (400) capable of transmitting thrust, wherein the transmission rod (400) is connected to the proximal end of the expandable portion (210) or the portion of the second tube segment (200) located proximal to the expandable portion (210), and when the transmission rod (400) is subjected to thrust, the expandable portion (210) can switch from the contracted state to the expanded state.

4. The sheath tube assembly according to claim 3, characterized in that: At least part of the transmission rod (400) is slidably sleeved on the outside of the retaining member (300); and / or the retaining member (300) is a retaining rope.

5. The sheath tube assembly according to claim 4, characterized in that: The joint between the retaining member (300) and the second tube section (200) is a first joint, and when the expandable portion (210) is in the expanded state, the transmission rod (400) is in upper limit contact with the first joint in a direction extending from the proximal end to the distal end of the sheath.

6. The sheath assembly according to any one of claims 2 to 5, characterized in that: When the expandable portion (210) is in the contracted state, a portion of the expandable portion (210) is sleeved inside the first pipe section (100) or the second pipe section (200); One of the first pipe section (100) and the second pipe section (200) that is capable of being sleeved outside the expandable portion (210) is provided with a deformation notch (111), the deformation notch (111) passes through the side wall of the first pipe section (100) or the second pipe section (200), and the deformation notch (111) extends to the end surface of the first pipe section (100) or the second pipe section (200) close to the expandable portion (210).

7. The sheath tube assembly according to any one of claims 1 to 5, characterized in that: The distal end of the second tube section (200) is capable of bending following the active bending section (710) of the endoscope, the plane in which the bending direction of the second tube section (200) lies is a first plane, the axis of the sheath tube is located in the first plane, and the retaining member (300) is disposed inside the sheath tube and is located on one side of the first plane; and / or, When the expandable portion (210) is in the contracted state, the second tube segment (200) is in limited contact with the first tube segment (100) in a direction extending from the distal end to the proximal end of the sheath tube; and / or When the expandable portion (210) is in the expanded state, the second tube segment (200) is in limited contact with the first tube segment (100) in a direction extending from the proximal end to the distal end of the sheath tube; and / or, The first tube segment (100) has a storage space for accommodating a passive bending segment (720) of an endoscope, the axis of the storage space is located on a first side of the axis of the first tube segment (100), and the other side of the axis of the first tube segment (100) is a second side opposite to the first side. The first tube segment (100) is provided with a force-applying structure, and the force-applying structure can apply a force in a first direction to the passive bending segment (720) located in the storage space, wherein the first direction is a direction extending from the second side to the first side.

8. The sheath tube assembly according to claim 7, characterized in that: The force-applying structure comprises a protrusion (500) radially protruding from the inner wall of the first tube section (100), the protrusion (500) being connected to the first tube section (100), and the protrusion (500) extending radially to the accommodating space so that the protrusion (500) contacts the passive bending section (720) located in the accommodating space, and the passive bending section (720) cooperates with the protrusion (500) in an upper limit position in a direction opposite to the first direction.

9. The sheath tube assembly according to claim 8, characterized in that: The protrusion (500) comprises a first protrusion (510) and a second protrusion (520), the first protrusion (510) and the second protrusion (520) being respectively located on two sides of the first tube segment (100) along a second direction, the second direction being respectively perpendicular to the first direction and the axial direction of the first tube segment (100); The first convex portion (510) and the second convex portion (520) both include an abutment area (501) capable of contacting the passive bending section (720); the abutment area (501) of the first convex portion (510) and the abutment area (501) of the second convex portion (520) are both located on the side of the axis of the accommodating space facing the second side; along the second direction, the abutment area (501) of the first convex portion (510) and the abutment area (501) of the second convex portion (520) are staggered.

10. A guide sheath, characterized in that: Comprising the sheath assembly according to any one of claims 1 to 9.

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