Wire-free pacemaker for pace-making of left bundle branch area and delivery sheath tube of wire-free pacemaker

Abstract

The invention discloses a leadless pacemaker for pace-making in a left bundle branch area and a delivery sheathing canal thereof.The leadless pacemaker comprises a pacemaker body, the center of the pacemaker body is partially provided with a first internal thread section, and a pacemaker electrode is partially provided with a first external thread section; the first internal thread section and the first external thread section are matched and screwed, so that the pacemaker electrode can be controlled to extend or retract by rotating the pacemaker electrode; when the pacemaker is used, the front end of the pacemaker body is flush with the front end of the shell, and the front end of the pacemaker electrode and the electrode spiral structure of the pacemaker electrode extend out of the pacemaker body by the maximum distance of 10 mm. The device can be safely and effectively implanted into the left bundle branch area, is stable for a long time and cannot be fractured or dislocated, and pace-making of the left bundle branch area is achieved.

Description

Technical Field

[0001] The present invention relates to a leadless cardiac pacemaker, in particular to a leadless pacemaker for left bundle branch area pacing and a delivery sheath thereof. Background Art

[0002] Leadless pacemakers are a hot new pacemaker product in recent years. This implantable electronic device integrates all the electronic components of the pacemaker system into a miniaturized device, which is implanted directly into the heart chamber to contact the myocardium and provide pacing therapy. Compared with traditional pacemakers implanted via transvenous wires, leadless pacemakers have significant advantages such as smaller size, easier implantation, and the absence of a chest pocket. They can significantly reduce the risk of infection, reduce complications, have a more aesthetically pleasing appearance without incisions, and improve patient comfort. They are expected to become the mainstream pacemaker product of the future.

[0003] Theoretically, leadless pacemakers are currently the most ideal cardiac implantable electronic device. However, their indications are limited. One important reason is that the pacing site is still the traditional right ventricular apex or septum, which can cause complete electrical desynchronization between the left and right ventricles, significantly increasing the patient's risk of pacing-mediated cardiomyopathy, atrial fibrillation, and heart failure. It is currently believed that if the pacemaker can be located in the normal conduction system of the left bundle branch of the heart to achieve left bundle branch area pacing (LBBAP), this electrical desynchronization caused by pacing stimulation can be avoided. However, the two currently marketed leadless pacemakers (Micra-TPS, manufactured by Medtronic, USA; AVEIR-VR, manufactured by Abbott, USA) are designed primarily for the traditional right ventricular apex or septum and cannot be implanted in the left bundle branch area. Abbott's latest generation product, AVEIR-CSP, which was recently announced at the American Heart Association Annual Meeting in May 2025, is the world's first leadless pacemaker that can be used for LBBAP. The key point of its design is that a retractable spiral is set at the head end, which can be screwed into the ventricular septum. However, actual clinical data show that the average screw-in depth of the spiral is only 5.4±0.9mm, while the left bundle branch area usually requires a screw-in depth of 8-10mm. Therefore, this product can only safely achieve deep septal pacing (DSP). In-depth analysis of the structure shows that this single-helix structure at the head end dare not be screwed very deep. Because the contraction of the heart itself will add a shear force to the spiral, there is a risk of direct fracture in the long term. Therefore, how to design a leadless pacemaker that can be safely and effectively screwed deep into the left bundle branch area is the current technical difficulty.

[0004] Currently published patents also attempt to design a leadless pacemaker that can achieve LBBAP. For example: (1) Leadless left bundle branch pacemaker (PCT / CN2022 / 122126): This device includes a housing and an implant core, the latter of which can be unscrewed from the housing and implanted in the left bundle branch area. However, this design is similar to the AVEIR-CSP product. Although it can be deeply screwed, the implant core is subject to greater myocardial contraction force and has a high risk of long-term rupture. (2) Biostimulator with hinge (CN116889686A): This solution mainly fixes the pacing electrode of the biostimulator to the ventricular septum, hinges the biostimulator at the hinge, and guides the shell of the biostimulator to the ventricular apex, so that the electrode axis of the pacing electrode extends in a direction different from the shell axis of the shell, which can achieve LBBAP. However, this design may have limited application. It is necessary to first implant the stimulator at the apex, then guide the electrode to the septum and then extend it deep into the ventricular septum. The operation is complicated and the promotion is not strong. Summary of the Invention

[0005] The purpose of the present invention is to provide a leadless pacemaker and its delivery sheath for left bundle branch area pacing, which can be safely and effectively implanted in the left bundle branch area, and has long-term stability without breakage or dislocation, thereby achieving left bundle branch area pacing.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A leadless pacemaker for left bundle branch area pacing, comprising:

[0008] A pacemaker body, wherein a pacemaker electrode is provided through the center thereof and has both ends protruding from the pacemaker body, and an electrode spiral structure is provided at the tip of the pacemaker electrode;

[0009] a housing, sleeved on the pacemaker body, wherein the head end of the housing is provided with an anchoring helical structure, and the diameter of the anchoring helical structure is the same as the diameter of the housing;

[0010] The center of the pacemaker body is partially provided with a first internal thread segment, and the pacemaker electrode is partially provided with a first external thread segment, the first internal thread segment and the first external thread segment are threadedly connected to each other so that the extension or retraction of the pacemaker electrode can be controlled by rotating the pacemaker electrode;

[0011] When in use, the front end of the pacemaker body is flush with the front end of the housing, and the front end of the pacemaker electrode and its electrode spiral structure extend out of the pacemaker body by a maximum distance of 10 mm.

[0012] Preferably, a plurality of annular protrusions are provided on the periphery of the pacemaker body, and the housing and the pacemaker body are integrated into one by an overmolding process.

[0013] Preferably, the outer periphery of the pacemaker body is provided with a second external thread segment; the inner wall of the housing is provided with a second internal thread segment, and the second external thread segment and the second internal thread segment are matched and screwed together;

[0014] The rear end of the pacemaker body is connected to a retraction twist control, and the pacemaker body is driven to rotate together by rotating the retraction twist control, thereby pushing or retracting the pacemaker body.

[0015] Preferably, the tail end of the pacemaker electrode is provided with at least one radial protrusion;

[0016] The tail end of the pacemaker electrode is arranged through the center of the recovery twist control and protrudes from the recovery twist control;

[0017] Preferably, the recovery twist control is cylindrical, and the diameter of the recovery twist control is smaller than the diameter of the pacemaker body;

[0018] The rear end surface of the recovery twist control is inwardly recessed and provided with a plurality of engaging grooves;

[0019] The front end surface of the recovery twist control is radially inward and recessed to the rear side to form an annular hook groove;

[0020] The tail end of the pacemaker body is provided with a cone surface, which is smoothly connected with the groove.

[0021] Preferably, the rear end of the housing is provided with a smooth section.

[0022] A delivery sheath for a leadless pacemaker for left bundle branch area pacing as described above, comprising:

[0023] The twist control tube body has a docking mechanism at its front end for docking with the recovery twist control unit, and a through hole is provided in the center of the twist control tube body and the docking mechanism;

[0024] a twist control cable, which is passed through the through hole and has a sleeve at its front end. The sleeve has at least one radial groove. The sleeve can be sleeved on the tail end of the pacemaker electrode so that the at least one radial protrusion is matched and engaged with the at least one radial groove, thereby rotating the pacemaker electrode by twisting the twist control cable;

[0025] An outer sleeve body is sleeved on the outer side of the torque control tube body;

[0026] The docking mechanism can match the meshing teeth inserted into the plurality of meshing grooves, and the docking mechanism and the pacemaker body can be rotated together by rotating the torque control tube body;

[0027] A ring body is also sleeved on the torque control tube body, and a plurality of nickel-titanium claws extend forward from the ring body. The ends of the plurality of nickel-titanium claws are hooked in the annular hook groove, and the position of the annular groove corresponds to the smooth section.

[0028] Preferably, the front end portion of the outer sleeve body extends into the smooth section of the outer shell and forms an interference fit;

[0029] The front end of the outer sleeve body is gradually thickened corresponding to the inner wall of the annular hook groove, thereby forcing the multiple nickel-titanium claws to hook into the annular hook groove;

[0030] The plurality of nickel-titanium hooks are arranged to have a tendency to return to a straight state.

[0031] Preferably, the cross-section of the radial protrusion is rectangular; and the radial groove gradually expands from the groove bottom to the groove mouth to be trapezoidal.

[0032] Preferably, a limiting protrusion is provided on the outer periphery of the docking mechanism or the docking mechanism is radially expanded to prevent the ring body from separating from the torque control tube body;

[0033] The outer sleeve body is a three-layer braided tube, the inner lining of which is made of PTFE or PI material, the middle layer is braided wire, and the outer layer is made of PEBAX material.

[0034] The advantages of the present invention are:

[0035] The present invention provides a leadless pacemaker for left bundle branch area pacing and its delivery sheath. The pacemaker electrode can be rotated so that the electrode spiral structure at the front end can be screwed into the left bundle branch area deep in the ventricular septum to achieve LBBAP. The screwing depth can be freely adjusted to accommodate patients with different ventricular septal thicknesses. The anchoring spiral structure at the front end of the housing can be screwed into the right side of the ventricular septum to provide support. The housing and anchoring spiral structure bear the primary stress of myocardial contraction, greatly reducing myocardial stress on the electrode spiral structure and preventing long-term fracture.

[0036] Furthermore, the wireless pacemaker is equipped with a special delivery sheath, which facilitates the manipulation of the pacemaker electrodes and the pacemaker body, and does not affect the original leadless pacemaker implantation operation habits.

[0037] Furthermore, the delivery sheath is connected to the leadless pacemaker via a nickel-titanium grabber and an outer sheath tube body, and the withdrawal and release are stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 1 is a schematic diagram of the three-dimensional structure of a leadless pacemaker for left bundle branch area pacing in an embodiment of the present invention;

[0039] Figure 2is a schematic cross-sectional view of a leadless pacemaker for left bundle branch area pacing according to an embodiment of the present invention;

[0040] Figure 3 is a schematic diagram of the three-dimensional structure of a leadless pacemaker for left bundle branch area pacing according to another embodiment of the present invention;

[0041] Figure 4 is a schematic cross-sectional view of a leadless pacemaker for left bundle branch area pacing according to another embodiment of the present invention;

[0042] Figure 5 1 is a schematic diagram of the front-end structure of a leadless pacemaker for left bundle branch area pacing according to another embodiment of the present invention;

[0043] Figure 6 is a schematic diagram of the back-end structure of a leadless pacemaker for left bundle branch area pacing according to another embodiment of the present invention;

[0044] Figure 7 is a schematic cross-sectional structural diagram of a pacemaker electrode in a maximum twisted-out state according to another embodiment of the present invention;

[0045] Figure 8 This is a schematic diagram of the three-dimensional structure of a leadless pacemaker for left bundle branch area pacing and its delivery sheath according to the present invention;

[0046] Figure 9 and Figure 10 This is a schematic diagram of the state where a torsion control rope is connected to the tail end of a pacemaker electrode according to the present invention;

[0047] Figures 11 to 13 It is a structural diagram of the docking mechanism and the recovery twist control;

[0048] Figure 14 This is a schematic diagram of a state in which a plurality of nickel-titanium hook claws are hooked in an annular hook groove according to the present invention;

[0049] Figure 15 This is a schematic cross-sectional view of a plurality of nickel-titanium hook claws hooked in an annular hook groove according to the present invention;

[0050] Figure 16 This is a schematic cross-sectional view of the structure of the present invention showing that the plurality of nickel-titanium hooks are restored to a straight line state due to the release of the outer tube body;

[0051] Figure 17 The present invention is a schematic diagram of the use process of a leadless pacemaker for left bundle branch area pacing and its delivery sheath. DETAILED DESCRIPTION

[0052] Preferred embodiments of the present invention are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely intended to illustrate the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art may adjust these embodiments as needed to suit specific applications.

[0053] It should be noted that, in the description of the present invention, terms such as "center," "front," and "rear" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. These are merely for ease of description and are not intended to indicate or imply that the device or component described must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0054] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0055] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0056] See Figure 1 and Figure 2 , which is the main structure of a leadless pacemaker for left bundle branch area pacing. This embodiment provides a leadless pacemaker for left bundle branch area pacing, including a pacemaker body 10 and a housing 20. The pacemaker body 10 is a cylindrical structure as a whole, with its front end gradually tapering into a cone shape. The overall size is about 38 mm long, about 6.5 mm in inner diameter, and about 1.1 cc in volume. It is equipped with electronic components and a microbattery to provide pacing and sensing functions. A pacemaker electrode 30 is provided in the center with both ends protruding from the pacemaker body 10. The tip of the pacemaker electrode 30 is provided with an electrode spiral structure 31, which can be made of a metal material with strong supporting force, such as nickel-titanium alloy.

[0057] The housing 20 is mounted on the pacemaker body 10. The housing 20 is approximately 48 mm long and 7.0 mm in diameter. The tip of the housing 20 is provided with an anchoring helical structure 21, the diameter of which is the same as that of the housing 20. The outer periphery of the pacemaker body 10 is provided with a plurality of annular protrusions 22. The housing 20 and the pacemaker body 10 are integrated into one body through an overmolding process. The front end of the pacemaker body 10 is flush with the front end of the housing 20. A first internal thread segment 11 is partially provided at the center of the pacemaker body 10, and a first external thread segment 32 is partially provided on the pacemaker electrode 30. The first internal thread segment 11 and the first external thread segment 32 are matingly screwed together so that the pacemaker electrode 30 can be controlled to extend or retract by rotating the pacemaker electrode 30. When in use, the front end of the pacemaker electrode 30 and its electrode helical structure 31 extend a maximum distance of 10 mm from the pacemaker body.

[0058] See Figures 3 to 7 , which illustrates the main structure of a leadless pacemaker for left bundle branch area pacing in another embodiment. In this embodiment, the outer periphery of the pacemaker body 10 is provided with a second externally threaded segment 12. The inner wall of the outer shell 20 is provided with a second internally threaded segment 23. The outer shell 20 is sleeved onto the pacemaker body 10, with the second externally threaded segment 12 and the second internally threaded segment 23 matingly threaded together. The outer shell 20 is approximately 48 mm long and 7.0 mm in diameter. The tip of the outer shell 20 is provided with an anchoring helical structure 21, and the rear end of the outer shell 20 is provided with a smooth segment, with the annular groove 15 positioned corresponding to the smooth segment. A retraction control 13 is connected to the rear end of the pacemaker body 10. Rotating the retraction control 13 drives the pacemaker body 10 to rotate, thereby pushing or retracting the pacemaker body 10. Similarly, the center of the pacemaker body 10 is partially provided with a first internally threaded segment 11, and the pacemaker electrode 30 is partially provided with a first externally threaded segment 32. The first internally threaded segment 11 and the first externally threaded segment 32 are matingly threaded together. The pacemaker electrode 30 can be pushed forward or retracted by rotating it. During use, the front end of the pacemaker body 10 is flush with the front end of the housing 20 when pushed to its maximum extent, and the front end of the pacemaker electrode 30 and its electrode spiral structure 31 extend a maximum of 10 mm from the pacemaker body.

[0059] The tail end of the pacemaker electrode 30 is provided with at least one radial protrusion 33. The tail end of the pacemaker electrode 30 is inserted through the center of the retraction knob 13 and protrudes from the retraction knob 13. The retraction knob 13 is cylindrical, with a diameter smaller than that of the pacemaker body 10. The rear end surface of the retraction knob 13 is recessed inwardly and has multiple engagement grooves 14. The front end surface of the retraction knob 13 is recessed radially inwardly and rearwardly to form an annular hook groove 15. The tail end of the pacemaker body 10 is provided with a tapered surface 16, which smoothly connects with the annular hook groove 15.

[0060] See Figures 8 to 16This embodiment also provides a delivery sheath for a leadless pacemaker for left bundle branch area pacing as described above, comprising: a torque control tube body 40, a torque control rope 50, and an outer sheath tube body 60.

[0061] The front end of the torque control tube body 40 is provided with a docking mechanism 41 for docking with the recovery torque control unit 13. A through-hole is provided through the center of the torque control tube body 40 and the docking mechanism 41. A torque control cable 50 is inserted into the through-hole. A sleeve 51 is provided at the front end of the torque control cable 50. The sleeve 51 has at least one radial groove 52. The sleeve 51 can be sleeved onto the tail end of the pacemaker electrode 30, with at least one radial protrusion 33 mating and engaging with the at least one radial groove 52. The pacemaker electrode 30 can then be rotated by twisting the torque control cable 50. Optionally, the radial protrusion 33 has a rectangular cross-section, while the radial groove 52 gradually expands from the bottom to the top into a trapezoidal shape. This facilitates docking of the torque control cable 50 with the pacemaker electrode 30.

[0062] The outer sleeve body 60 is sleeved on the outside of the torque control tube body 40; the outer sleeve body 60 is a three-layer braided tube, the inner lining of which is made of PTFE or PI material, the middle layer is braided wire, and the outer layer is made of PEBAX material.

[0063] The docking mechanism 41 mates with the meshing teeth 42 of the multiple meshing grooves 14. Rotating the control tube body 40 then causes the docking mechanism 41 and the pacemaker body 10 to rotate together. A ring 43 is also sleeved onto the control tube body 40. A plurality of nickel-titanium claws 44 extend forward from the ring 43, the ends of which engage within the annular hooking grooves 15. A retaining protrusion or radially expanding radial expansion of the docking mechanism 41 prevents the ring 43 from separating from the control tube body 40.

[0064] The front end of the outer sheath body 60 extends into the smooth section of the outer shell 20, forming an interference fit. The inner wall of the annular groove 15 at the front end of the outer sheath body 60 gradually thickens, forcing the multiple nickel-titanium hooks 44 into the groove 15, ensuring that they will not disengage even under low pull-out forces. The multiple nickel-titanium hooks 44 are designed to have a tendency to return to a straight state. Specifically, the nickel-titanium hooks 44 are compressed by the outer sheath body 60 to form a hook shape and then hook into the annular groove 15. The nickel-titanium hooks 44 have a shape memory function and a tendency to return to a straight state. After removal from the outer sheath, the nickel-titanium hooks 44 can return to a nearly straight state. Subsequently, the delivery sheath can be completely detached from the leadless pacemaker by retracting the control tube body 40.

[0065] See Figure 17The actual use process of the present invention is as follows: First, the leadless pacemaker and delivery sheath are delivered into the right ventricle through the deep venous system (preferably the femoral vein, secondarily the internal jugular vein) and reach the septum. Afterwards, the tail end of the delivery sheath is slightly rotated clockwise to allow the anchoring spiral structure 21 at the head end of its shell 20 to enter the myocardium on the right side of the ventricular septum for initial anchoring. Next, the raised part of the tail end of the delivery sheath is slightly rotated clockwise to allow the electrode spiral structure 31 at the head end of the pacemaker electrode 30 to gradually rotate deep into the myocardium of the ventricular septum, and deep twisting is performed according to the thickness of the patient's ventricular septum (the maximum deep twisting length is 10 mm) to reach the left bundle branch area on the left side of the ventricular septum, thereby achieving the left bundle branch pacing function. Once the pacing characteristics meet the requirements of left bundle branch pacing, the implantation is indicated, and the leadless pacemaker and the delivery sheath are separated. The leadless pacemaker is then implanted in the myocardium of the ventricular septum, and the delivery sheath is completely withdrawn from the body.

[0066] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A leadless pacemaker for left bundle branch area pacing, characterized in that: include: A pacemaker body, wherein a pacemaker electrode is provided through the center thereof and has both ends protruding from the pacemaker body, and an electrode spiral structure is provided at the tip of the pacemaker electrode; a housing, sleeved on the pacemaker body, wherein the head end of the housing is provided with an anchoring helical structure, and the diameter of the anchoring helical structure is the same as the diameter of the housing; The center of the pacemaker body is partially provided with a first internal thread segment, and the pacemaker electrode is partially provided with a first external thread segment, the first internal thread segment and the first external thread segment are threadedly connected to each other so that the extension or retraction of the pacemaker electrode can be controlled by rotating the pacemaker electrode; When in use, the front end of the pacemaker body is flush with the front end of the housing, and the front end of the pacemaker electrode and its electrode spiral structure extend out of the pacemaker body by a maximum distance of 10 mm.

2. The leadless pacemaker for left bundle branch area pacing according to claim 1, wherein: The outer periphery of the pacemaker body is provided with a plurality of annular protrusions, and the shell and the pacemaker body are integrated into one by an overmolding process.

3. The leadless pacemaker for left bundle branch area pacing according to claim 1, wherein: The outer periphery of the pacemaker body is provided with a second external thread segment; the inner wall of the shell is provided with a second internal thread segment, and the second external thread segment and the second internal thread segment are matched and screwed together; The rear end of the pacemaker body is connected to a retraction twist control, and the pacemaker body is driven to rotate together by rotating the retraction twist control, thereby pushing or retracting the pacemaker body.

4. The leadless pacemaker for left bundle branch area pacing according to claim 3, wherein: The tail end of the pacemaker electrode is provided with at least one radial protrusion; The tail end of the pacemaker electrode is arranged through the center of the recovery twist control and protrudes from the recovery twist control.

5. The leadless pacemaker for left bundle branch area pacing according to claim 4, wherein: The retraction twist control is cylindrical, and the diameter of the retraction twist control is smaller than the diameter of the pacemaker body; The rear end surface of the recovery twist control is inwardly recessed and provided with a plurality of engaging grooves; The front end surface of the recovery twist control is radially inward and recessed to the rear side to form an annular hook groove; The tail end of the pacemaker body is provided with a cone surface, which is smoothly connected with the groove.

6. The leadless pacemaker for left bundle branch area pacing according to claim 5, wherein: The rear end of the shell is provided with a smooth section.

7. A delivery sheath for a leadless pacemaker for left bundle branch area pacing according to claim 6, characterized in that: include: The twist control tube body has a docking mechanism at its front end for docking with the recovery twist control unit, and a through hole is provided in the center of the twist control tube body and the docking mechanism; a twist control cable, which is passed through the through hole and has a sleeve at its front end. The sleeve has at least one radial groove. The sleeve can be sleeved on the tail end of the pacemaker electrode so that the at least one radial protrusion is matched and engaged with the at least one radial groove, thereby rotating the pacemaker electrode by twisting the twist control cable; An outer sleeve body is sleeved on the outer side of the torque control tube body; The docking mechanism can match the meshing teeth inserted into the plurality of meshing grooves, and the docking mechanism and the pacemaker body can be rotated together by rotating the torque control tube body; A ring body is also sleeved on the torque control tube body, and a plurality of nickel-titanium claws extend forward from the ring body. The ends of the plurality of nickel-titanium claws are hooked in the annular hook groove, and the position of the annular groove corresponds to the smooth section.

8. The delivery sheath according to claim 7, wherein: The front end portion of the outer sleeve body extends into the smooth section of the outer shell and forms an interference fit; The front end of the outer sleeve body is gradually thickened corresponding to the inner wall of the annular hook groove, thereby forcing the multiple nickel-titanium claws to hook into the annular hook groove; The plurality of nickel-titanium hooks are arranged to have a tendency to return to a straight state.

9. The delivery sheath according to claim 7, wherein: The cross section of the radial protrusion is rectangular; the radial groove gradually expands from the groove bottom to the groove mouth and becomes trapezoidal.

10. The delivery sheath according to claim 7, wherein: The outer periphery of the docking mechanism is provided with a limiting protrusion or the docking mechanism is radially expanded to prevent the ring body from separating from the torque control tube body; The outer sleeve body is a three-layer braided tube, the inner lining of which is made of PTFE or PI material, the middle layer is braided wire, and the outer layer is made of PEBAX material.

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