Wire extraction device

Abstract

The present invention provides a removal device for removing a slender structure implanted in the body, the removal device includes a control handle, a sheath connected to the distal end of the control handle, and an expansion head connected to the distal end of the sheath, wherein the control handle includes a driving member and a rotating member, one end of the rotating member is connected to the proximal end of the sheath, and the other end of the rotating member is connected to the driving member, the driving member is used to drive the rotating member to rotate in both directions, so as to drive the sheath and the expansion head to rotate in both directions; not only can the expansion head effectively cut the fibrous tissue wrapped around the slender structure, but also can prevent other wires in the blood vessel from being entangled with each other and prevent the blood vessel wall from being twisted and scratched by the expansion head.

Description

Technical Field

[0001] The present invention relates to the technical field of interventional medical devices, and in particular to a lead extraction device for extracting an electrode lead implanted in a patient's body for a long period of time. Background Art

[0002] Many medical procedures and surgical procedures require the implantation of elongated structures within the body of a human or livestock patient. These elongated structures may include catheters, sheaths, cardiac electrical leads (e.g., pacemaker leads or defibrillator leads), and a variety of other devices. A pacemaker is typically implanted in a pocket of subcutaneous tissue within the patient's chest wall. Multiple leads extend from the pacemaker through a vein into the patient's heart chambers. Defibrillator leads may be secured inside or outside the heart.

[0003] In some cases, it is necessary to remove the wire implanted in the patient's body, such as when the wire implanted in the patient's body is disconnected and cannot transmit signals, a large amount of fibrous (or calcified) tissue forms at the tip of the electrode, causing the pacemaker to be unable to provide enough energy to operate, infection at the wire site, clots or scar tissue blocking the vein, or other malfunctions. Since the slender structure is implanted in the patient's body for a long time, a lot of fibrous (or calcified) tissue will be attached to the wire, causing multiple wires, between the wire and the blood vessel wall, or between the wire and the inner wall of the heart to be attached together. The wire cannot be directly removed, and forced removal may cause wire breakage, damage to the surrounding intact wires, damage to the blood vessel wall or the inner wall of the heart, and other problems. At present, the wire removal technology uses a wire removal device to complete the process. The wire removal device generally uses a cutting tip to perform unidirectional rotational motion along a wire to cut the fibrous tissue.

[0004] However, stripping away the fibrous tissue growing around a single lead may require one or more cuts with the cutting tip. If the fibrous tissue is not completely separated from the lead, continuing to rotate the cutting tip in the original direction can easily pull on the fibrous tissue and cause it to entangle around the cutting tip, sometimes even multiple times. In this case, the fibrous tissue pulling on the blood vessel can cause it to twist and be scratched by the dilator tip. If multiple leads are wrapped in fibrous tissue within the same vessel, the other leads can easily become entangled with the one lead due to the traction of the fibrous tissue, greatly increasing the difficulty of lead removal. Summary of the Invention

[0005] The present invention provides a removal device for removing a slender structure implanted in the body, wherein the removal device includes a control handle, a sheath connected to the distal end of the control handle, and an expansion head connected to the distal end of the sheath, wherein the control handle includes a driving member and a rotating member, one end of the rotating member is connected to the proximal end of the sheath, and the other end of the rotating member is connected to the driving member, and the driving member is used to drive the rotating member to rotate in both directions, thereby driving the sheath and the expansion head to rotate in both directions.

[0006] The control handle of the removal device of the present invention can drive the expansion head and the sheath to move within the patient's blood vessel, and the control handle can control the driving member to drive the rotating member to rotate in both directions. The bidirectional rotation of the rotating member can drive the sheath and the expansion head to rotate in both directions. In the process in which the proximal end of the slender structure passes through the expansion head and the sheath in sequence and extends out of the removal device from the control handle to the outside of the body, the expansion head and the sheath are pushed toward the distal end in the blood vessel to cut the fibrous tissue wrapped around the slender structure and separate the slender structure from the inner wall of the blood vessel. Since the control handle can drive the sheath and the expansion head to rotate in both directions by driving the rotating member, that is, the expansion head rotates in a first direction and then in a second direction, not only can the expansion head effectively cut the fibrous tissue wrapped around the slender structure, but it can also reduce the chance of the slender structure and other wires in the blood vessel being entangled with each other, and the chance of the blood vessel wall being scratched by the expansion head due to traction and twisting. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the implementation. Obviously, the drawings described below are some implementations of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0008] Figure 1 It is a structural schematic diagram of the removal device provided in an embodiment of the present invention.

[0009] Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure of the removal device.

[0010] Figure 3 yes Figure 2 Schematic diagram of the three-dimensional structure of the worm and worm wheel assembly.

[0011] Figure 4 yes Figure 3 An enlarged schematic diagram of the worm in FIG.

[0012] Figure 5 yes Figure 3 An enlarged schematic diagram of the worm gear assembly and sheath tube connector.

[0013] Figure 6 yes Figure 3 A cross-sectional view of the assembled worm gear assembly, worm and sheath tube joint.

[0014] Figure 7 yes Figure 2 Partial cross-sectional view of .

[0015] Figure 8 yes Figure 7 Schematic diagram of one state of the cash withdrawal device.

[0016] Figure 9 yes Figure 1 A schematic cross-sectional view of another view of the removal device in FIG. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0018] In addition, the description of the following embodiments is with reference to the attached diagrams to illustrate specific embodiments in which the present invention can be implemented. The directional terms mentioned in the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only with reference to the directions of the attached diagrams. Therefore, the directional terms used are for better and clearer explanation and understanding of the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. "The connection between component A and component B" means that component A is directly in contact with component B, or that component A is indirectly connected to component B through other components.

[0019] In order to more clearly describe the structure of the retrieval device, the limiting terms "proximal", "distal" and "axial" described in the present invention are commonly used terms in the field of interventional medicine. Specifically, "distal" refers to the end away from the operator during the surgical operation; "proximal" refers to the end close to the operator during the surgical operation; "axial" refers to the direction of the central axis of the device, and the radial direction is the direction perpendicular to the central axis. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The common terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not to be understood as limitations of the present invention.

[0020] See also Figure 1 and Figure 2 , Figure 1 1 is a schematic structural diagram of a removal device 100 provided in a first embodiment of the present invention; Figure 2 yes Figure 1 The present invention provides a retrieval device 100 for removing a slender structure implanted in the body. The slender structure can be, but is not limited to, a catheter, sheath, pacemaker or defibrillator electrode wire, and various other devices that have been implanted in the patient's body. In this application, the electrode wire 500 (such as Figure 9 It is understood that the elongated structure may also be other tubular grafts implanted in the patient's body for a long time as described above.

[0021] The retrieval device 100 includes a control handle 20, a sheath 50 connected to the distal end of the control handle 20, and a dilator head 80 connected to the distal end of the sheath 50. The handle 20, sheath 50, and dilator head 80 are provided with a threading lumen 201 for transmitting the guidewire 500 along the axial direction of the retrieval device 100. In the retrieval device 100 provided by the present invention, the control handle 20 can control the bidirectional rotation of the sheath 50 and dilator head 80. The distal end of the dilator head 80 has a blade for cutting the fibrous tissue surrounding the guidewire 500, thereby cutting through or otherwise rupturing obstacles encountered during the removal of the guidewire 500. Bidirectional rotation refers to the sheath 50 and dilator head 80 rotating in a first direction and then in a second direction, the first direction being opposite to the second direction. The first direction can be clockwise or counterclockwise when viewed from the proximal end to the distal end of the retrieval device 100, and the second direction can be counterclockwise or clockwise, respectively.

[0022] When using the removal device 100, the doctor inserts the proximal end of the electrode wire 500 in the patient's body into the inner cavity of the expansion head 80. The doctor grasps the control handle 20 and pushes the control handle 20 distally, so that the sheath 50 and the expansion head 80 gradually enter the patient's blood vessel along the electrode wire. When the resistance of pushing the control handle 20 distally is large, it means that the expansion head 80 has come into contact with the tissue bound around the wire 500. The control handle 20 is then used to control the bidirectional rotation of the sheath 50 and the expansion head 80, so that the sharp blade of the expansion head 80 cuts the tissue bound around the electrode wire, separating the wire from the tissue, and facilitating the subsequent wire removal operation. The bidirectional rotation of the sheath 50 and the expansion head 80 can also reduce the chance of the wire 500 becoming entangled with other wires in the blood vessel and the chance of the blood vessel wall being twisted and scratched by the expansion head 80.

[0023] Specifically, the control handle 20 includes a housing 21, the interior of the housing 21 is provided with a storage chamber 211 for accommodating other components, the control handle 20 also includes a driving member and a rotating member provided in the storage chamber 211, the rotating member is connected to the distal end of the driving member, the control handle 20 also includes an operating member 26 partially accommodated in the storage chamber 211, the sheath 50 is partially accommodated at the distal end of the storage chamber 211, wherein the operating member 26 is connected to the proximal end of the driving member and is used to receive external tension, and the end (proximal end) of the sheath 50 away from the expansion head 80 enters the storage chamber 211 through the distal opening of the housing 21 and is connected to the rotating member. Under the action of the external tension, the operating member 26 drives the driving member to move axially toward the proximal end, and the axial movement of the driving member drives the rotating member to rotate in both directions, thereby driving the sheath 50 and the expansion head 80 to rotate in both directions.

[0024] Please also refer to Figures 2 to 5 The driving member includes a worm 23, which is axially slidably disposed within the receiving cavity 211 of the housing 21. The proximal end of the worm 23 is fixedly connected to the operating member 26. The operating member 26 moves axially to drive the worm 23 to move axially. In this embodiment, the worm 23 is fixedly connected to the operating member 26 by a pin. In other embodiments, the proximal end of the worm 23 and the operating member 26 can be fixed by screwing or clamping, so that the worm 23 and the operating member 26 are movably connected as a whole.

[0025] The outer circumference of the worm 23 is provided with a bidirectional helical groove 231, with both ends of the bidirectional helical groove 231 extending helically in opposite directions. The worm 23 includes a rod body 230, the outer surface of which is provided with a bidirectional helical groove 231 and a connecting post 235. The bidirectional helical groove 231 is used to drive the rotating member, while the connecting post 235 is fixedly connected to the operating member 26. The bidirectional helical groove 231 is located at the distal end of the rod body 230 relative to the connecting post 235.

[0026] like Figure 4 As shown, the bidirectional spiral groove 231 includes a first guide groove 232 extending helically at the distal end of the outer circumference of the worm 23, and a second guide groove 233 extending helically at the proximal end of the first guide groove 232. The first guide groove 232 extends helically in a first direction, and the second guide groove 233 extends helically in a second direction, with the first and second directions being opposite. In this embodiment, when viewed from the proximal end to the distal end of the removal device 100, the first direction is clockwise, and the second direction is counterclockwise. In an alternative embodiment, the first direction is counterclockwise, and the second direction is clockwise.

[0027] Furthermore, the bidirectional spiral groove 231 includes a switching portion 234 connected between the first guide groove 232 and the second guide groove 233. After the rotating wheel 251 passes over the switching portion 234, the worm 23 drives the worm wheel assembly 25 to rotate in the opposite direction. The distal end of the first guide groove 232 extends to the distal end surface of the rod body 230, that is, the first guide groove 232 forms an opening at the distal end surface of the rod body 230. The switching portion 234 is a transition groove between the first guide groove 232 and the second guide groove 233. Preferably, the switching portion 234 is a smooth transition groove.

[0028] like Figure 3 As shown, the rotating part includes a worm gear assembly 25, which is formed with a through hole for the worm 23 to pass through, and the surface of the worm gear assembly 25 is also provided with a guide pin 2510 for being inserted into the bidirectional spiral groove 231; during the axial movement of the worm 23, the guide pin 2510 slides in the bidirectional spiral groove 231, and the two ends of the bidirectional spiral groove 231 respectively drive the worm gear assembly 25 to rotate in opposite directions through the guide pin 2510. That is, during the process of the guide pin 2510 sliding from the proximal end to the distal end of the bidirectional spiral groove 231, or during the process of sliding from the distal end to the proximal end of the bidirectional spiral groove 231, the bidirectional spiral groove 231 is used to drive the worm gear assembly 25 to rotate in two opposite directions, that is, the bidirectional spiral groove 231 is used to drive the worm gear assembly 25 to rotate in two opposite directions in a time-sharing or sequential manner. The proximal end of the sheath 50 is connected to the housing 21 ( Figure 1 ) is inserted into the receiving cavity 211 and connected to the worm gear assembly 25, and the sheath 50 rotates in the opposite direction with the worm gear assembly 25.

[0029] The worm gear assembly 25 includes a rotating wheel 251 and a connecting tube 255. The rotating wheel 251 is connected to the proximal edge of the connecting tube 255. In this embodiment, the rotating wheel 251 is connected to the proximal end of the inner cavity of the connecting tube 255. The rotating wheel 251 is sleeved on the rod body 230 of the worm 23 and is slidably connected to the rod body 230. The connecting tube 255 is sleeved on the rotating wheel 251. The proximal end of the sheath 50 is sleeved inside the distal end of the connecting tube 255. The distal end of the sheath 50 passes through the distal end of the connecting tube and extends to the distal end of the retrieval device 100.

[0030] Please combine Figure 4 See Figure 5 The rotating wheel 251 is annular, i.e., a through hole is formed in the middle of the rotating wheel 251 along the axial direction, and the rotating wheel 251 is sleeved on the worm 23 through the through hole. The rotating wheel 251 is provided with at least one guide pin 2510 protruding into the through hole and slidably inserted into the bidirectional spiral groove 231.

[0031] When the guide pin 2510 slides from the proximal end to the distal end of the bidirectional spiral groove 231 and from the distal end to the proximal end of the bidirectional spiral groove 231 , the bidirectional spiral groove 231 is used to drive the worm gear assembly 25 to rotate in two opposite directions in a time-sharing manner.

[0032] The distal end of the bidirectional spiral groove 231 passes through the distal end surface of the worm 23. As the worm 23 slides axially, the guide pin 2510 of the rotating wheel 251 slides in the bidirectional spiral groove 231. Specifically, the guide pin 2510 slides along the first guide groove 232, passes over the steering switch 234, and then slides into the second guide groove 233. The rotating wheel 251 slides along the second guide groove 233, passes over the steering switch 234, and then slides into the first guide groove 232, thereby driving the rotating wheel 251 and the connecting tube 255 to rotate bidirectionally, causing the sheath tube 50 and the expansion tip 80 to rotate bidirectionally along with the connecting tube 255.

[0033] In other embodiments, the guide pin 2510 may also be disposed at other positions on the rotating wheel 251 , such as a surface of the rotating wheel 251 facing toward or away from the sheath tube 50 .

[0034] like Figure 5 As shown, in this embodiment, to ensure force balance on the rotating wheel 251, two guide pins 2510 are provided. These two guide pins 2510 are positioned opposite each other on the surface of the rotating wheel 251 and extend into the through hole. The two guide pins 2510 can be located at the same axial position on the rotating wheel 251 or at different axial positions. The two guide pins 2510 are slidably inserted into the bidirectional helical groove 231 of the worm 23. Accordingly, two bidirectional helical grooves 231 are provided on the surface of the rod body 230, with each guide pin 2510 correspondingly accommodated in one bidirectional helical groove 231. In embodiments where the two guide pins 2510 are positioned at different axial positions, the two guide pins 2510 can be inserted into the same bidirectional helical groove 231. In alternative embodiments, multiple guide pins 2510 and multiple bidirectional helical grooves 231 can be provided, and the number of guide pins 2510 and bidirectional helical grooves 231 can be unequal. In an altered embodiment, the guide pin 2510 is hemispherical, or is a spirally extended strip protruding from the inner surface of the rotating wheel 251 toward the through hole, and the shape of the guide pin 2510 matches the bidirectional spiral groove 231 to be accommodated in the bidirectional spiral groove 231.

[0035] The edge of the rotating wheel 251 is fixedly connected or movably connected to the connecting tube 255, that is, the rotating wheel 251 and the connecting tube 255 are connected by means of clamping or bonding. In this embodiment, a clamping hole 2512 is provided on the outer wall of the rotating wheel 251, and the clamping hole 2512 is used to clamp the clamping block 2554 on the connecting tube 255. Figure 2-Figure 3 and Figure 5As shown, the distal end of the connecting cylinder 255 is provided with a through hole for passing the worm 23. Driven by the rotating wheel 251, the connecting cylinder 255 rotates around the worm 23. In other embodiments, when the connecting cylinder 255 is long enough (the control handle is long enough), the inner cavity of the connecting cylinder 255 is used to accommodate the rod body 230, and the rod body 230 does not need to be sleeved on the connecting cylinder 255.

[0036] The connecting tube 255 includes a tube body 2551 sleeved on the edge of the rotating wheel 251 and a first engaging portion disposed at the distal end of the tube body 2551 .

[0037] A plurality of clamping blocks 2554 are provided at the proximal end of the cylinder body 2551 . The clamping blocks 2554 are used to be clamped into the clamping holes 2512 of the rotating wheel 251 , so that the rotating wheel 251 and the connecting cylinder 255 are connected together.

[0038] The first engaging portion includes a connecting ring 2553 protruding from the inner surface of the connecting cylinder 255 and a first rack 2556 disposed on the connecting ring 2553. The connecting ring 2553 is annular or partially annular, and the through hole formed by the connecting ring 2553 is used to pass through the worm 23. The first rack 2556 includes a series of protrusions protruding toward the rotating wheel 251.

[0039] Please also refer to Figure 2 and Figure 5 The sheath tube 50 includes a sheath tube connector 52 connected to the connecting tube 255 and an inner sheath tube 54 connected to the distal end of the sheath tube connector 52. One end of the sheath tube connector 52 facing away from the inner sheath tube 54 is connected to the connecting tube 255.

[0040] like Figure 2 As shown, in this embodiment, the sheath connector 52 and the inner sheath 54 are fixed by screw connection. Specifically, the distal end of the sheath connector 52 is provided with an internal thread, and the proximal end of the inner sheath 54 is provided with an external thread. After the internal thread and the external thread are assembled in place, they are fixed with thread glue, thereby fixing the sheath connector 52 and the inner sheath 54 together. The sheath connector 52 and the inner sheath 54 can also be fixed by other methods, such as welding.

[0041] like Figure 3 As shown, the sheath connector 52 is a cylindrical structure, comprising a tube body 521 inserted into the connecting ring 2553 and a second engaging portion protruding from the outer surface of the proximal end of the tube body 521 .

[0042] The second engagement portion includes a snap ring 523 and a second rack 5232 disposed on the snap ring 523. The second rack 5232 is disposed at the proximal end of the sheath connector 52 and includes a series of protrusions protruding toward the first rack 2556.

[0043] The first meshing portion is configured to mesh with the second meshing portion. When the first and second meshing portions are meshed, the second meshing portion engages with the first rack 2556 of the first meshing portion via the second rack 5232, enabling the sheath connector 52 to move synchronously with the rotating wheel 251 and the connecting tube 255. Specifically, the first rack 2556 and the second rack 5232 are configured to be detachably meshed together, i.e., the protrusions on the first rack 2556 and the second rack 5232 match in shape and face each other after assembly.

[0044] Furthermore, if Figure 5 As shown, the rotating wheel 251 also includes a rotating ring 2511 and a first elastic member 2515 arranged at the distal end of the rotating ring 2511. The rotating ring 2511 is annular, forming a through hole for passing the worm 23, and is used to carry the first elastic member 2515. The opposite ends of the first elastic member 2515 elastically abut the distal end of the rotating ring 2511 and the proximal end of the sheath tube connector 52 along the axial direction, pushing the second engaging portion on the sheath tube connector 52 toward the direction of the first engaging portion on the connecting tube 255, so that the second engaging portion engages with the first engaging portion, and the sheath tube 50 rotates following the connecting tube 255.

[0045] In this embodiment, the first elastic member 2515 includes a spring and a resisting member for abutting the sheath connector 52. The rotating wheel 251 defines a connecting groove, and the spring is accommodated in the connecting groove. The proximal end of the spring abuts the bottom wall of the connecting groove, and the distal end of the spring abuts the resisting member. Preferably, the first elastic member 2515 is a spring plunger.

[0046] In this embodiment, in order to balance the force on the proximal surface of the sheath 50, the number of the first elastic members 2515 is 3, and the three first elastic members 2515 are evenly arranged along the circumference of the rotating wheel 251, that is, the angle between each adjacent two first elastic members 2515 and the axis of the rotating wheel 251 is 120 degrees.

[0047] Please also refer to Figure 2 and Figure 7 The worm gear assembly 25 and the sheath connector 52 are both rotatably received in the receiving chamber 211 of the housing 21. The difference is that the worm gear assembly 25 can move forward and backward in the axial direction, while the sheath connector 52 is restricted in the axial direction and cannot move forward and backward, thereby achieving a disengageable mutual engagement between the first and second meshing portions. When the first and second meshing portions are engaged with each other, the sheath connector 52 rotates synchronously with the worm gear assembly 25. Specifically, the housing 21 is provided with a receiving groove 212 for accommodating the worm gear assembly 25, and is also provided with a second limiting portion 218 and a third limiting portion 219 for limiting the position of the sheath connector 52.

[0048] The worm gear assembly 25 is movably received within the receiving groove 212. The two side walls of the receiving groove 212 are respectively provided with a first reinforcing rib 214 and a second reinforcing rib 215 spaced apart along the axial direction. The first reinforcing rib 214 is closer to the proximal end than the second reinforcing rib 215. The bottom wall of the receiving groove 212 forms the housing 21 between the first reinforcing rib 214 and the second reinforcing rib 215.

[0049] Furthermore, the first and second reinforcing ribs 214, 215 both extend circumferentially along the receiving groove 212 and protrude toward the axis. In this embodiment, the first and second reinforcing ribs 214, 215 are both annular. It is understood that the first and second reinforcing ribs 214, 215 could also be polygonal, rectangular, or otherwise with a central opening. The receiving groove 212 defines a receiving space 216, and the worm gear assembly 25 is accommodated within the receiving space 216 between the first and second reinforcing ribs 214, 215.

[0050] The axial dimension between the adjacent surfaces of the first reinforcing rib 214 and the second reinforcing rib 215 is greater than the sum of the axial extension length of the worm gear assembly 25 and the meshing depth between the first rack 2556 and the second rack 5232, thereby allowing the worm gear assembly 25 to move forward and backward in the axial direction. The radial dimension of the receiving space 216 is slightly greater than the radial dimension of the worm gear assembly 25, and the cross-section of the receiving groove 212 perpendicular to the axial direction (radial direction) is circular, thereby allowing the worm gear assembly 25 to rotate about its axis within the receiving groove 212. In this embodiment, the inner wall of the housing 21 between the first reinforcing rib 214 and the second reinforcing rib 215 is used to limit the worm gear assembly 25 in the radial direction, so that the axis of the worm gear assembly 25 coincides with the axis of the worm 23, and the worm 23, worm gear assembly 25, sheath 50, expansion head 80 and removal device 100 are coaxial.

[0051] In a modified embodiment, a receiving groove is provided on the inner wall of the outer shell 21 along its circumference, and a convex ring is provided on the outer circumference of the worm gear assembly 25 so as to be movably accommodated in the receiving groove. The length of the receiving groove extending along the axial direction of the outer shell 21 is greater than the length of the convex ring extending along the axial direction of the outer shell 21, and the convex ring can slide axially and rotate in the receiving groove.

[0052] In a modified embodiment, a convex ring is provided on the inner wall of the outer shell 21 along its circumference toward the receiving cavity 211, and a receiving groove is provided on the outer peripheral surface of the worm gear assembly 25 along its circumference. The convex ring can be movably accommodated in the receiving groove, and the length of the receiving groove extending along the axial direction of the outer shell 21 is greater than the length of the convex ring extending along the axial direction of the outer shell 21, so that the convex ring can slide axially and rotate in the receiving groove.

[0053] like Figure 2As shown, the inner wall of the receiving chamber 211 of the housing 21 is provided with a first limiting portion 217 for limiting the radial movement of the worm 23. The first limiting portion 217 is provided at the proximal end of the receiving groove 212, and the first limiting portion 217 extends from the inner wall of the receiving chamber 211 to the receiving chamber 211. Specifically, the first limiting portion 217 is an annular plate provided on the inner wall of the housing 21. The first limiting portion 217 forms a through hole along the axial direction, and the worm 23 is inserted axially into the through hole of the first limiting portion 217 and can slide axially. The axial centerline of the through hole coincides with the axial centerline of the worm 23, and the inner diameter of the through hole of the first limiting portion 217 is slightly larger than the outer diameter of the worm 23, so as to limit the radial direction of the worm 23 in the removal device 100.

[0054] A second stopper 218 is disposed on the inner wall of the receiving cavity 211 of the housing 21 and is used to limit the sheath connector 52 in the radial direction of the retrieval device 100. The second stopper 218 is disposed at the distal end of the receiving groove 212 and is an annular plate that protrudes from the inner wall of the housing 21 into the receiving cavity 211. The second stopper 218 forms an axial through-hole, into which the sheath connector 52 is inserted. The inner diameter of the through-hole of the second stopper 218 is slightly larger than the outer diameter of the corresponding sheath connector 52, thereby limiting the radial position of the sheath connector 52 in the retrieval device 100.

[0055] like Figure 2 and Figure 9 As shown, the distal end of the inner wall of the receiving cavity 211 of the housing 21 is provided with a third limiting portion 219 for limiting the sheath tube 50 in the radial and axial directions. The third limiting portion 219 is provided adjacent to the distal end of the housing 21 relative to the second limiting portion 218. The third limiting portion 219 protrudes from the inner wall of the housing 21 toward the receiving cavity 211 and is in the shape of an annular plate in this embodiment. The distal end of the sheath tube connector 52 located in the housing 21 is provided with a limiting groove 5212 ( Figure 9 ), the third limiting portion 219 is used to be rotatably accommodated in the limiting groove 5212 to limit the radial and axial movement range of the proximal end of the sheath 50, so that the sheath 50 can hardly move axially and radially relative to the shell 21, and the sheath 50 can rotate relative to the shell 21.

[0056] In the modified embodiment, the first limiting portion, the second limiting portion and the third limiting portion can adopt the first reinforcing rib 214 and the second reinforcing rib 215 as described above ( Figure 7 ) implementation method, or other limiting methods commonly used in this field to limit the components, which will not be described here.

[0057] Please also refer to Figure 3 and Figure 6When assembling the worm 23, the worm gear assembly 25 and the sheath tube connector 52, the rotating wheel 251 is rotatably sleeved on the outside of the rod body 230. Specifically, the guide pin 2510 of the rotating wheel 251 is slidably inserted into the first guide groove 232 from the distal end of the rod body 230; the end of the tube body 521 of the sheath tube connector 52 away from the clamping ring 523 is inserted from the proximal end into the barrel 2551 of the connecting tube 255 and passes through the distal end through hole of the connecting tube 255 until the second rack 5232 of the clamping ring 523 is connected to the connecting ring. The first racks 2556 of the worm 23 and the rotating wheel 251 are meshed with each other; the assembled worm 23 and the rotating wheel 251 are installed in the connecting tube 255. Specifically, one end of the rod body 230 provided with the bidirectional spiral groove 231 is inserted into the inner cavity of the sheath tube connector 52 from the proximal end of the sheath tube connector 52, and the rotating wheel 251 is clamped to the connecting tube 255. Specifically, the clamping blocks 2554 of the connecting tube 255 are respectively clamped into the corresponding clamping holes 2512 of the rotating wheel 251, so that the connecting tube 255 and the rotating wheel 251 are fixedly connected. At this time, the first elastic member 2515 elastically pushes the clamping ring 523 to mesh the first rack 2556 with the second rack 5232; the distal end of the rod body 230 is inserted into the inner cavity of the sheath tube connector 52, driving the worm wheel assembly 25 to rotate bidirectionally relative to the worm 23.

[0058] like Figure 2 As shown, the control handle 20 is further provided with a second elastic member 265 at its proximal end that moves synchronously with the worm 23. The second elastic member 265 is used to drive the operating member 26 to move toward the distal end. Specifically, the second elastic member 265 is housed in the storage chamber 211 of the housing 21, and the opposite ends of the second elastic member 265 respectively abut against the proximal end of the connecting portion 261 of the operating member 26 and the proximal boundary of the storage chamber 211. The operating member 26 is used to receive an external pulling force to drive the worm 23 to slide axially toward the proximal end and compress the second elastic member 265. When the external pulling force disappears, the second elastic member 265 rebounds and generates an elastic restoring force for pushing the operating member 26 and the worm 23 to move toward the distal end. In this embodiment, the second elastic member 265 is a spring.

[0059] The control handle is provided with a tubular sheath 267 at one end of the second elastic member 265 near the operating member 26. The sheath 267 includes a tubular main body 2671 and a bent portion 2673 extending from the main body 2671 toward the axis. The main body 2671 is sleeved around the distal end of the second elastic member 265, and the distal end of the second elastic member 265 can be compressed or stretched axially within the main body 2671. The side of the bent portion 2673 facing the proximal end abuts the distal end of the second elastic member 265, and the side of the bent portion 2673 facing the distal end abuts the proximal end of the operating member 26. The axial extension length of the main body 2671 is greater than the axial extension length of the guide groove 213. During the process in which the sheath 267 and the second elastic member 265 slide synchronously with the operating member 26, the sheath 267 can prevent the second elastic member 265 from deforming radially and entering the guide groove 213 or passing through the guide groove 213 and extending outside the housing 21.

[0060] like Figure 2 As shown, the proximal end of the housing 21 defines a guide slot 213 axially connected to the housing cavity 211. The operating member 26 comprises a first portion and a second portion extending from the first portion to at least one side. The first portion is housed within the inner cavity of the housing 21, while the second portion extends through the guide slot 213 to the exterior of the housing 21. The operating member 26 is capable of sliding along the guide slot 213. In this embodiment, the first portion comprises a connecting portion 261, and the second portion comprises handles 263 disposed on opposite sides of the connecting portion 261. The connecting portion 261 is axially slidable within the housing 21, and the two handles 263 extend through the guide slot 213 to the exterior of the housing 21. The proximal end of the worm 23 is connected to the connecting portion 261, which slides axially to drive the worm 23 in this direction. The guide slot 213 extends axially and is sufficiently long to allow the operating member 26 to slide forward and backward along the guide slot 213, while also limiting the circumferential motion of the operating member 26, preventing it from rotating about the axial direction. Therefore, the operating member 26 can drive the worm 23 to slide in the axial direction along the guide groove 213 , but cannot drive the worm 23 to rotate in the circumferential direction.

[0061] In this embodiment, two opposing guide slots 213 are defined in the housing 21. Pulling the operating member 26 proximally causes the connecting portion 261 to slide along the guide slots 213. The sliding of the connecting portion 261 then causes the worm 23 to slide. It will be appreciated that in alternative embodiments, the operating member 26 includes a connecting portion 261 that slides along the guide slots 213 and a handle extending outward from the connecting portion 261. The handle extends through the guide slots 213 to the exterior of the housing 21.

[0062] Please refer again Figure 2 、 Figure 4 and Figure 9The worm 23 is provided with a threading channel 2301 along the axial direction, and the threading channel 2301 is connected to the threading lumen of the sheath 50. The proximal opening formed at the proximal end of the threading channel 2301 is located on the side wall of the worm 23. The proximal end of the wire 500 passes through the expansion head 80, the threading lumen of the sheath 50 and the threading channel 2301 of the worm 23 in sequence and then passes out from the outer shell 21, so that the operator, such as a surgeon, can remove the wire from the control handle 20 after stripping the fibrous tissue.

[0063] like Figure 9 As shown, a wire outlet hole 2101 is provided on the side wall of the housing 21, corresponding to the opening of the wire passage 2301. The proximal end of the wire 500 passes through the distal opening of the wire passage 2301 and then extends out of the removal device 100 through the wire outlet hole 2101. The wire outlet hole 2101 is located near the proximal end of the operating member 26. The distal opening of the wire passage 2301 extends axially, and the proximal end of the wire 500 extends through the distal opening to the wire outlet hole 2101.

[0064] The housing 21 is further provided with a guide portion 2105, which extends from the edge of the wire outlet hole 2101 toward the distal opening of the wire threading channel 2301. The wire 500 at the distal opening of the wire threading channel 2301 slides out of the wire outlet hole 2101 along the guide portion 2105. Preferably, the distal end of the guide portion 2105 abuts against the boundary of the wire threading channel 2301 facing away from the distal opening. When the worm 23 slides axially toward the proximal end, the distal end of the guide portion 2105 slides within the distal opening. The guide portion 2105 is seamlessly connected to the boundary of the wire threading channel 2301, does not block the proximal end of the wire 500, and more easily passes the proximal end of the wire 500 through the wire outlet hole 2101 along the guide portion 2105.

[0065] like Figure 2As shown, the housing 21 is a tubular structure with a sealed proximal end. The housing 21 includes a body 209 and an end block 210 that are interconnected. The body 209 extends axially, and the aforementioned receiving cavity 211, receiving groove 212, first stopper 217, second stopper 218, and third stopper 219 are all disposed within the body 209. The end block 210 is connected to the proximal end of the body 209 and extends in a different direction from the body 209. In this embodiment, the end block 210 extends perpendicularly to the direction of extension of the body 209, that is, the end block 210 extends in a radial direction perpendicular to the axial direction. It is understood that in alternative embodiments, the end block 210 and the body 209 may extend in directions other than parallel or perpendicular. Furthermore, the end block 210 may extend radially from the proximal end of the body 209 to one or both sides, or circumferentially. Specifically, in this embodiment, the end block 210 is symmetrical about the axial direction (axis). In other words, the end block 210 extends radially from the proximal end of the body 209 to opposite sides. Furthermore, the end block 210 is fishtail-shaped, which can increase the contact area with the surgeon's fingers, facilitating operation. In alternative embodiments, the end block 210 can also adopt other shapes, such as a bar, a cone, a three-dimensional shape including a free-form surface, or other regular or irregular shapes.

[0066] The distal end of the housing 21 is provided with a hollow soft rubber nozzle 2107 , through which the sheath 50 is passed; an outer sheath 55 is provided on the periphery of the sheath 50 , and the proximal end of the outer sheath 55 is inserted into the soft rubber nozzle 2107 .

[0067] like Figure 2 As shown, the worm gear assembly 25, worm 23 and sheath tube connector 52 assembled into one are installed in the housing 21. Specifically, the worm gear assembly 25 is accommodated in the accommodating space 216 of the housing 21, and the connecting column 235 of the worm 23 is connected to the distal end of the connecting portion 261. The first limiting portion 217 supports the worm 23 so that the worm 23 can slide axially; the guide portion 2105 can be slidably inserted into the slide groove 2303; the second limiting portion 218 supports the tube body 521 of the sheath tube connector 52, and the third limiting portion 219 can be rotatably inserted into the limiting groove 5212 of the tube body 521, so that the sheath tube connector 52 can rotate with the worm gear assembly 25 but cannot slide axially. The proximal end of the sheath tube 50 is fixedly connected to the distal end of the sheath tube connector 52 by screwing. At this time, the expansion head 80 and the threading inner cavity of the sheath tube 50, the threading channel of the worm 23 and the outlet hole 2101 of the housing 21 (as shown in FIG. Figure 9 As shown in the figure, the two parts are interconnected to form a continuous inner cavity 201 for transmitting the wire 500, so as to facilitate the insertion of the wire 500.

[0068] Please also refer to Figure 2 、 Figure 7 and Figure 9During the specific operation of removing the device 100, the doctor inserts the proximal end of the wire 500 in the patient's body, such as the electrode wire, into the threading lumen of the expansion head 80; the doctor grasps the control handle 20 and pushes the control handle 20 distally, so that the sheath 50 and the expansion head 80 gradually enter the patient's blood vessel along the electrode wire 500; when the resistance to pushing the control handle 20 distally is large, it means that the expansion head 80 has come into contact with the tissue surrounding the wire 500.

[0069] Pulling the operating member 26 toward the proximal end drives the worm 23 to slide axially toward the proximal end, and the worm 23 drives the worm gear assembly 25 to move proximally until the proximal end of the rotating wheel 251 hits the first reinforcing rib 214, and the gap between the distal end surface of the connecting tube 255 and the second reinforcing rib 215 increases; the first elastic member 2515 elastically pushes the clamping ring 523 to engage the first rack 2556 with the second rack 5232. The worm 23 slides toward the proximal end, and the inner surface of the second guide groove 233 slides against the guide pin 2510 of the rotating wheel 251 to drive the rotating wheel 251 to rotate along the first direction (i.e., clockwise direction when viewed from the proximal end to the distal end of the removal device 100); since the rotating wheel 251 is fixedly connected to the connecting tube 255, and the first rack 2556 is engaged with the second rack 5232, the rotating wheel 251 drives the sheath connector 52, the sheath 50 and the expansion head 80 to rotate along the first direction, so that the sharp blade of the expansion head 80 cuts the tissue combined around the guide wire 500.

[0070] Continue to pull the operating member 26 toward the proximal end to drive the worm 23 to continue sliding axially toward the proximal end. After the guide pin 2510 of the rotating wheel 251 slides along the second guide groove 233 to cross the steering switching part 234, the guide pin 2510 of the rotating wheel 251 slides along the first guide groove 232 to drive the rotating wheel 251 to rotate along the second direction (i.e., counterclockwise direction viewed from the proximal end to the distal end of the removal device 100); the rotating wheel 251 drives the sheath connector 52, the sheath 50 and the expansion head 80 to rotate along the second direction, so that the sharp blade of the expansion head 80 cuts the tissue combined around the electrode wire; until the operating member 26 slides proximally along the guide groove 213 to the proximal end of the connecting part 261 against the proximal end of the bidirectional spiral groove 231.

[0071] During the entire process of pulling the operating member 26 toward the proximal end, the worm 23 first drives the rotating member and the sheath 50 to rotate in the first direction. When the guide pin 2510 passes the steering switching portion 234, the worm 23 then drives the rotating member and the sheath 50 to rotate in the second direction. This not only enables the expansion head 80 to effectively cut the fibrous tissue wrapped around the guide wire 500, but also prevents other guide wires in the blood vessel from being entangled with each other and prevents the blood vessel wall from being twisted and scratched by the expansion head 80.

[0072] As can be seen from the detailed operation of the removal device 100, the operating member 26 compresses the second elastic member 265 during a first period and a second period. During the first period, the guide pin 2510 slides within the second guide slot 233, specifically from the proximal end of the second guide slot 233 to the diversion switching portion 234, causing the worm gear assembly 25 to rotate clockwise relative to the worm 23. During the second period, the guide pin 2510 slides within the first guide slot 232, specifically from the diversion switching portion 234 to the distal end of the first guide slot 232, causing the worm gear assembly 25 to rotate counterclockwise relative to the worm 23. Specifically, during the process of the operating member 26 compressing the second elastic member 265, the linear motion of the worm 23 is converted into rotation of the worm gear assembly 25, and the worm gear assembly 25 achieves bidirectional rotation relative to the worm 23, first clockwise and then counterclockwise. In this embodiment, the angles of both clockwise and counterclockwise rotation of the sheath 50 are approximately 280 degrees.

[0073] Please also refer to Figure 2 、 Figure 8 and Figure 9 During the proximal movement of the worm 23, the second elastic member 265 is compressed and elastically deformed. The elastic restoring force generated by the rebound of the compressed second elastic member 265 is used to propel the worm 23 toward the distal end. When the tension on the control handle 20 is released, that is, the operating member 26 of the control handle 20 is released, the elastic force generated by the second elastic member 265 pushes the operating member 26 toward the distal end, causing the worm 23 to slide axially toward the distal end. The worm 23 drives the worm gear assembly 25 to move distally until the distal end of the rotating member abuts the second reinforcing rib 215, and the gap between the proximal end surface of the rotating wheel 251 and the first reinforcing rib 214 increases. Since the sheath connector 52 is axially fixed relative to the housing 21, the gap between the connecting ring 2553 and the clamping ring 523 increases until the gap between the first rack 2556 and the second rack 2532 exceeds the maximum meshing depth between the two, causing the first rack 2556 and the second rack 5232 to disengage from each other, that is, the sheath connector 52 and the worm gear assembly 25 are no longer engaged. After the first meshing portion and the second meshing portion are disengaged from each other, the worm gear assembly 25 continues to rotate driven by the axial movement of the worm 23 , and the rotation of the worm gear assembly 25 does not drive the sheath tube connector 52 , the sheath tube 50 and the expansion head 80 to rotate.

[0074] After the first meshing portion and the second meshing portion are disengaged from each other, the inner surface of the first guide groove 232 on the worm 23 continues to slide against the guide pin 2510 of the rotating wheel 251 to drive the rotating wheel 251 to continue to rotate in the first direction; since the sheath tube connector 52 and the worm gear assembly 25 are disengaged from each other, the friction force generated by the first elastic member 2515 of the worm gear assembly 25 on the sheath tube connector 52 cannot drive the sheath tube connector 52 to rotate, therefore, the end of the first elastic member 2515 slides along the proximal surface of the clamping ring 523.

[0075] Since the rotating wheel 251 is fixedly connected to the connecting tube 255, the second elastic member 265 continues to push the operating member 26 to slide toward the proximal end, and the operating member 26 continues to drive the worm 23 to slide axially toward the distal end. After the guide pin 2510 of the rotating wheel 251 slides along the first guide groove 232 to pass over the steering switching portion 234, the guide pin 2510 of the rotating wheel 251 slides along the second guide groove 233 to drive the rotating wheel 251 to rotate in the second direction again; however, the rotating wheel 251 will not drive the sheath tube connector 52, the sheath tube 50 and the expansion head 80 to rotate.

[0076] During the rebound of the second elastic member 265, that is, after the operating member 26 is released, the sheath 50 and the expansion head 80 will not rotate with the worm gear assembly 25, thereby reducing the load of the rotation of the worm gear assembly 25, which is conducive to the guide pin 2510 of the rotating wheel 251 to slide smoothly from the distal end of the first guide groove 232 to the proximal end of the second guide groove 233, avoiding the guide pin 2510 from getting stuck in the bidirectional spiral groove 231, especially near the steering switching part 234.

[0077] When the operating member 26 slides along the guide groove 213 to near the proximal end of the guide groove 213 , specifically, when the worm 23 moves from the proximal end to the farthest end within its axial motion range, the first rack 2556 and the second rack 5232 engage with each other.

[0078] like Figures 2 to 3 As shown, the thrust directed to the proximal end exerted by the first elastic member 2515 on the rotating wheel 251 is the first thrust, and the thrust directed to the distal end exerted by the second elastic member 265 on the rotating wheel 251 through the worm 23 is the second thrust. During the rebound of the second elastic member 265, the elastic force gradually decreases, that is, the second thrust gradually decreases. When the first thrust is greater than the second thrust, the first elastic member 2515 pushes the rotating wheel 251 and the connecting tube 255 to move proximally relative to the sheath tube connector 52 until the first rack 2556 engages with the second rack 5232, that is, the first meshing portion and the second meshing portion engage with each other, thereby realizing that the second elastic member 265, the operating member 26, the worm 23 and the worm gear assembly 25 return to the initial position, making it convenient for the user to pull the control handle 20 toward the proximal end again.

[0079] In other embodiments, the first elastic member 2515, the first rack 2556, and the second rack 5232 are omitted from the worm gear assembly 25. The connecting tube 255 is directly fixedly connected to the sheath connector 52, i.e., the distal end of the connecting tube 255 is fixedly connected to the proximal end of the sheath connector 52 (e.g., the connecting tube 255 and the sheath connector 52 are integrally formed), and the proximal end of the sheath connector 52 cannot be separated from the worm gear assembly 25. In other words, in this embodiment, the process of the worm 23 moving toward the proximal end is the same as in the above embodiment. During the process of the worm 23 moving toward the distal end, the worm gear assembly 25 drives the sheath connector 52 to rotate synchronously. That is, after the operating member 26 is released, the sheath 50 and the expansion head 80 rotate bidirectionally along with the worm gear assembly 25.

[0080] The above is an implementation of the embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the embodiment of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A retrieval device for removing an elongated structure implanted in the body, characterized in that: The removal device includes a manipulation handle, a sheath connected to the distal end of the manipulation handle, and an expansion head connected to the distal end of the sheath, wherein the manipulation handle includes a driving member and a rotating member, one end of the rotating member is connected to the proximal end of the sheath, and the other end of the rotating member is connected to the driving member, and the driving member is used to drive the rotating member to rotate in both directions, thereby driving the sheath and the expansion head to rotate in both directions; The driving member includes a worm, the outer circumference of the worm is provided with a bidirectional spiral groove, and the two ends of the bidirectional spiral groove respectively extend in opposite directions; The rotating member includes a worm wheel assembly, the worm wheel assembly is formed with a through hole for passing the worm, and the surface of the worm wheel assembly is further provided with a guide pin for inserting into the bidirectional spiral groove; During the axial movement of the worm, the guide pin slides in the bidirectional spiral groove, and the two ends of the bidirectional spiral groove respectively drive the worm gear assembly to rotate in opposite directions through the guide pins. During the process of the guide pin sliding from the proximal end to the distal end of the bidirectional spiral groove, or from the distal end to the proximal end of the bidirectional spiral groove, the bidirectional spiral groove is used to drive the worm gear assembly to rotate in two opposite directions; The worm gear assembly comprises: a rotating wheel, the guide pin being provided on the surface of the rotating wheel; and A connecting cylinder is buckled on the edge of the rotating wheel, and both the connecting cylinder and the rotating wheel are provided with the through hole for passing the worm in the axial direction; Driven by the worm, the rotating wheel rotates in two opposite directions, and the connecting cylinder moves synchronously with the rotating wheel.

2. The removal device according to claim 1, characterized in that: The bidirectional spiral groove includes a first guide groove arranged on the outer peripheral surface of the worm and a second guide groove connected to the proximal end of the first guide groove, the first guide groove extends spirally along a first direction, and the second guide groove extends spirally along a second direction, and the directions of the spiral extensions in the first direction and the second direction are opposite.

3. The removal device according to claim 2, characterized in that: The bidirectional spiral groove includes a steering switching portion, which is connected between the first guide groove and the second guide groove. After the guide pin passes over the steering switching portion, the worm drives the worm gear assembly to rotate in the opposite direction.

4. The removal device according to claim 1, characterized in that The connecting cylinder and the rotating wheel are clamped and fixed to each other.

5. The removal device according to claim 4, characterized in that: The sheath tube comprises a sheath tube connector and an inner sheath tube, two ends of the inner sheath tube are respectively connected to the expansion head and the sheath tube connector, and the proximal end of the sheath tube connector is connected to the worm gear assembly.

6. The removal device according to claim 5, characterized in that: The sheath tube joint is fixedly connected to the connecting tube of the worm gear assembly.

7. The removal device according to claim 5, characterized in that: The proximal end of the sheath tube connector and the distal end of the connecting tube are sleeved together.

8. The removal device according to claim 7, characterized in that: The through holes are provided at corresponding positions of the proximal end and the distal end of the connecting tube; The proximal end of the sheath tube connector is sleeved inside the distal end of the connecting tube, and the distal end of the sheath tube connector passes through the through hole at the distal end of the connecting tube and extends to the outside of the connecting tube.

9. The removal device according to claim 8, characterized in that: The distal end of the connecting tube is formed with a first engaging portion protruding toward the proximal end of the sheath tube connector, and the proximal end of the sheath tube connector is provided with a second engaging portion protruding toward the first engaging portion. When the first engaging portion and the second engaging portion engage with each other, the sheath tube connector moves synchronously with the connecting tube.

10. The removal device according to claim 9, characterized in that: The first engaging portion includes a first rack provided on the connecting tube, and the second engaging portion includes a second rack provided on the sheath tube connector. The first rack is detachably engaged with the second rack.

11. The removal device according to claim 9, characterized in that: The sheath tube connector is fixed in axial position; When the worm moves axially proximally, the rotating wheel drives the connecting tube to follow the worm and move proximally relative to the sheath connector, so that the first meshing portion and the second meshing portion mesh with each other; When the worm moves axially distally, the rotating wheel drives the connecting tube to follow the worm and move distally relative to the sheath tube connector, so that the first meshing portion and the second meshing portion that are meshed with each other gradually disengage.

12. The removal device according to claim 11, characterized in that: After the first meshing portion and the second meshing portion are disengaged from each other, the worm gear assembly continues to rotate driven by the axial movement of the worm.

13. The removal device according to claim 11, characterized in that: When the worm moves from the proximal end to the distal end within its axial motion range, the first meshing portion and the second meshing portion mesh with each other.

14. The removal device according to claim 13, characterized in that The rotating wheel includes a rotating ring and a first elastic member arranged at the distal end of the rotating ring. The two ends of the first elastic member elastically abut the distal end of the rotating ring and the proximal end of the sheath tube connector in the axial direction, so that the first meshing portion and the second meshing portion are ensured to mesh with each other during the process of the worm moving toward the proximal end and when the worm moves to the farthest end within its axial motion range.

15. The removal device according to claim 14, characterized in that: The control handle is further provided with a second elastic member at its proximal end that moves synchronously with the worm; When the worm moves toward the proximal end, the second elastic member is compressed and elastically deformed, and the elastic restoring force generated by the rebound of the compressed second elastic member is used to push the worm to move toward the distal end; The thrust directed toward the proximal end applied by the first elastic member to the rotating wheel is a first thrust, and the thrust directed toward the distal end applied by the second elastic member to the rotating wheel through the worm is a second thrust. During the rebound of the second elastic member, when the first thrust is greater than the second thrust, the first elastic member pushes the rotating wheel to move toward the proximal end relative to the sheath tube connector, so that the first engaging portion and the second engaging portion engage with each other.

16. The removal device according to claim 15, characterized in that The control handle also includes an operating member connected between the worm and the second elastic member, and the operating member is used to receive external tension to drive the worm to slide axially toward the proximal end and compress the second elastic member. After the external tension disappears, the second elastic member rebounds and generates an elastic restoring force for pushing the operating member and the worm to move toward the distal end.

17. The removal device according to claim 12, characterized in that: The manipulation handle further comprises a shell, and the inner wall surface of the shell is provided with a limiting portion extending toward the axis of the removal device, and the limiting portion is used to limit the axial movement range of the sheath tube connector.

18. The removal device according to claim 17, characterized in that The sheath tube connector is provided with a limiting groove corresponding to the limiting portion, and the limiting portion is used to be accommodated in the limiting groove, and the limiting portion is used to limit the movement range of the sheath tube connector in the radial and axial directions.

19. The removal device according to claim 18, characterized in that The inner wall of the shell is provided with a receiving groove, and the worm gear assembly is used to be received in the receiving groove. The two side walls of the receiving groove are respectively a first reinforcing rib and a second reinforcing rib arranged at intervals along the axial direction. The axial length of the worm gear assembly is the worm gear length, and the axial meshing length of the first meshing portion and the second meshing portion is the meshing depth. The axial dimension between the mutually adjacent surfaces of the first reinforcing rib and the second reinforcing rib is greater than the sum of the worm gear length and the meshing depth.

20. The removal device according to claim 17, characterized in that The driving member and the rotating member are arranged in the inner cavity of the shell, and the proximal end of the sheath tube connector is inserted into the inner cavity of the shell from the distal end of the shell and then connected to the rotating member.

21. The removal device according to claim 17, characterized in that The outer shell is provided with a guide groove penetrating to the inner cavity thereof, and the guide groove extends in the axial direction; The control handle also includes an operating member connected to the proximal end of the worm, the operating member includes a first part and a second part extending from the first part to at least one side, the first part is accommodated in the inner cavity of the shell, the second part extends to the outside of the shell through the guide groove, and the operating member can slide along the guide groove.

22. The removal device according to claim 17, characterized in that The expansion head and the sheath are both provided with a threading lumen for transmitting the slender structure, the worm has a threading channel axially opened, the outer shell is provided with a threading hole corresponding to the opening of the threading channel, and the proximal end of the slender structure extends out of the removal device through the threading lumen of the expansion head, the threading lumen of the sheath, the threading channel and the threading hole in sequence.

23. The removal device according to claim 22, characterized in that The distal opening of the threading channel is opened on the side wall of the worm, and the housing is also provided with a guide portion, which extends from the edge of the wire outlet hole into the distal opening of the threading channel, and the slender structure at the distal opening of the threading channel slides out of the wire outlet hole along the guide portion.

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