Mandrel assembly, conveying mechanism and medical system

Abstract

The invention provides a core shaft assembly, a conveying mechanism and a medical system. The core shaft assembly comprises a core shaft body and a core shaft, the pre-tightening assembly is arranged on the mandrel body and comprises a self-expanding structural part and a limiting part; the near end of the self-expanding structural member and the mandrel body are kept relatively static, and the far end of the self-expanding structural member can move in the axial direction of the mandrel body; when the far end of the self-expanding structural member moves in the direction from the far end to the near end, the self-expanding structural member is switched from the radial contraction state to the radial expansion state, and when the far end of the self-expanding structural member moves in the direction from the near end to the far end, the self-expanding structural member is switched from the radial expansion state to the radial contraction state; the limiting part is located on the far end side of the self-expanding structural part and used for abutting against the far end of the self-expanding structural part so as to limit the maximum distance of the far end of the self-expanding structural part moving from the near end to the far end. Comprising the mandrel assembly can effectively prevent a target object from being out of load when the target object is conveyed.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a core shaft assembly, a conveying mechanism and a medical system. Background Art

[0002] Cerebrovascular disease is a major disease that threatens human life and health, and interventional therapy has become the main method for treating this disease. Interventional therapy usually involves delivering vascular implants such as blood flow guide devices to the lesion site through a delivery mechanism and releasing them.

[0003] The delivery mechanism usually includes a core shaft and a microcatheter. The core shaft is partially inserted into the microcatheter, and the distal end of the core shaft is loaded with a vascular implant. The core shaft is pushed along the microcatheter to push the vascular implant so that the vascular implant reaches the lesion site, and then the microcatheter is withdrawn to complete the release of the vascular implant. Therefore, during the pushing process, the core shaft needs to be kept moving synchronously with the vascular implant to avoid the vascular implant being unloaded and causing implantation failure.

[0004] In one prior art, a self-expanding body is provided at the distal end of the core shaft, and the proximal end of the self-expanding body is fixedly connected to the core shaft. The distal end of the self-expanding body can move on the core shaft, and the radial expansion or contraction of the self-expanding body is controlled by the movement of the distal end of the self-expanding body. The inner surface of the vascular implant is used to contact the outer surface of the self-expanding body. When the vascular implant is pushed, friction is generated between the inner surface of the vascular implant and the outer surface of the self-expanding body, and the vascular implant moves with the core shaft under the action of the friction. However, in practice, the core shaft may shake during the pushing process, which may cause the distal end of the self-expanding body to move from the proximal end to the distal end, resulting in a reduction in the outer diameter of the self-expanding body, and then the self-expanding body separates from the vascular implant and causes the vascular implant to be unloaded. Summary of the invention

[0005] The object of the present invention is to provide a mandrel assembly, a conveying mechanism and a medical system, aiming to improve the loading reliability of a vascular implant and reduce or even avoid the unloading of the vascular implant.

[0006] To achieve the above object, the present invention provides a mandrel assembly, comprising:

[0007] a mandrel body; and,

[0008] A preload assembly is arranged on the core shaft body and includes a self-expanding structural member and a limiting member; the proximal end of the self-expanding structural member remains relatively still with the core shaft body, and the distal end of the self-expanding structural member can move along the axial direction of the core shaft body; the core shaft assembly is configured so that when the distal end of the self-expanding structural member moves in the direction from the distal end to the proximal end, the self-expanding structural member switches from a radially contracted state to a radially expanded state, and when the distal end of the self-expanding structural member moves in the direction from the proximal end to the distal end, the self-expanding structural member switches from a radially expanded state to a radially contracted state; the limiting member is located on the distal side of the self-expanding structural member, and is used to abut against the distal end of the self-expanding structural member to limit the maximum distance that the distal end of the self-expanding structural member moves from the proximal end to the distal end.

[0009] Optionally, the core shaft assembly includes a plurality of the pre-tightening components, and the plurality of the pre-tightening components are arranged sequentially along the axial direction of the core shaft body.

[0010] Optionally, the self-expanding structural member comprises a self-expanding body, and when the self-expanding body is in a radially contracted state, the self-expanding structural member is in a radially contracted state, and when the self-expanding body is in a radially expanded state, the self-expanding structural member is in a radially expanded state;

[0011] The self-expanding body includes a proximal gathering portion, a distal gathering portion and a plurality of support rods. The proximal gathering portion is sleeved on the core shaft body and remains relatively stationary with respect to the core shaft body. The distal gathering portion is movably sleeved on the core shaft body. The plurality of support rods are arranged around the core shaft body, and the proximal ends of all the support rods are connected to the proximal gathering portion, and the distal ends of all the support rods are connected to the distal gathering portion.

[0012] Optionally, the support rod includes a first segment, a second segment and a third segment connected in sequence from the proximal end to the distal end, and the first segment and the third segment are symmetrical to each other; the distance from the second segment to the core shaft body is greater than the distance from the first segment to the core shaft body, and the ratio of the width of the first segment to the width of the second segment is 0.3 to 1.

[0013] Optionally, a ratio of a width of the first segment to a width of the second segment is 0.4 to 0.8.

[0014] Optionally, the support rod includes a first segment, a second segment and a third segment connected in sequence from the proximal end to the distal end, and the first segment and the third segment are symmetrical to each other; the distance from the second segment to the core shaft body is greater than the distance from the first segment to the core shaft body; when the self-expanding body is in a radially expanded state, the ratio of the length of the second segment to the length of the self-expanding body is 0.1 to 1.

[0015] Optionally, when the self-expanding body is in a radially expanded state, a ratio of the length of the second segment to the length of the self-expanding body is 0.1 to 0.5.

[0016] Optionally, the self-expanding structure further includes a coating, wherein the coating at least covers an outer surface and / or an inner surface of a region of the self-expanding body corresponding to the second segment.

[0017] Optionally, the self-expanding body is cut from a tube, and when the inner diameter of the tube is 0.017 inch to 0.033 inch, the number of the support rods is 5 to 20.

[0018] Optionally, the self-expanding structural member comprises a self-expanding body, and when the self-expanding body is in a radially contracted state, the self-expanding structural member is in a radially contracted state, and when the self-expanding body is in a radially expanded state, the self-expanding structural member is in a radially expanded state;

[0019] The self-expanding structural member further comprises a developing wire which is wound around at least a portion of the outer surface of the self-expanding body.

[0020] Optionally, the limiting member is configured to have a developing property.

[0021] To achieve the above objectives, the present invention further provides a conveying mechanism, comprising a microcatheter and a core shaft assembly as described in any of the preceding items, wherein the microcatheter is used to be sleeved on a portion of the outer circumference of the core shaft assembly and wrap the preload component.

[0022] To achieve the above-mentioned purpose, the present invention also provides a medical system, including a target object and a conveying mechanism as described above, wherein the target object is configured to be able to expand or contract radially; the target object is arranged in the microcatheter, and is sleeved on a portion of the outer circumference of the core shaft assembly, and covers the preload component; the distal end of the self-expanding structural member abuts against the limit member, and the self-expanding structural member applies a radially outward force to the target object.

[0023] Compared with the prior art, the mandrel assembly, conveying mechanism and medical system of the present invention have the following advantages:

[0024] The aforementioned core shaft assembly includes a core shaft body and a pre-tightening component, wherein the pre-tightening component is arranged on the core shaft body and includes a self-expanding structural member and a limiting member; the proximal end of the self-expanding structural member remains relatively stationary with the core shaft body, and the distal end of the self-expanding structural member can move along the axial direction of the core shaft body; the core shaft assembly is configured so that when the distal end of the self-expanding structural member moves in the direction from the distal end to the proximal end, the self-expanding structural member switches from a radially contracted state to a radially expanded state, and when the distal end of the self-expanding structural member moves from the proximal end to the distal end, the self-expanding structural member switches from a radially expanded state to a radially contracted state; the limiting member is located on the distal side of the self-expanding structural member, and is used to abut against the distal end of the self-expanding structural member to limit the maximum distance that the distal end of the self-expanding structural member moves from the proximal end to the distal end. The core shaft assembly can be applied to a delivery mechanism, and the delivery mechanism also includes a microcatheter, which is used to be sleeved on a portion of the outer circumference of the core shaft assembly and wrap the pre-tightening component. The delivery mechanism is used to deliver a target object, and the target object is, for example, a vascular implant. The vascular implant is used to be arranged in the microcatheter and sleeved on a portion of the outer circumference of the core shaft assembly, and wrap the pre-tightening component; at the same time, the distal end of the self-expanding structural member abuts against the stopper, and the self-expanding structural member applies a radially outward force to the vascular implant. The limiter is provided to limit the maximum distance that the distal end of the self-expanding structural member moves from the proximal end to the distal end, which actually limits the minimum outer diameter of the self-expanding structural member. In this way, even if the mandrel assembly shakes during the pushing of the mandrel assembly, the distal end of the self-expanding structural member will not continue to move from the proximal end to the distal end to cause the outer diameter of the self-expanding structural member to further decrease. This allows the self-expanding structural member to continuously exert a radially outward force on the vascular implant stent to prevent the vascular implant from being unloaded. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to better understand the present invention and do not constitute an improper limitation of the present invention.

[0026] Figure 1 is a schematic structural diagram of a mandrel assembly provided by the present invention according to an embodiment;

[0027] Figure 2 is a schematic structural diagram of a self-expanding body of a core shaft assembly provided according to an embodiment of the present invention, wherein the self-expanding body is in a radially expanded state;

[0028] Figure 3 is a schematic structural diagram of a self-expanding body of a core shaft assembly provided according to an embodiment of the present invention, wherein the self-expanding body is in a radially contracted state;

[0029] Figure 4is a schematic diagram of a mandrel assembly provided by an embodiment of the present invention being applied to a conveying mechanism to load a target object;

[0030] Figure 5 1 is a schematic diagram of an application scenario of a core shaft assembly provided by an embodiment of the present invention, in which the core shaft assembly passes through a tortuous blood vessel, and the self-expanding body is woven from a wire material, and the microcatheter and the target object are omitted in the diagram;

[0031] Figure 6 1 is a schematic diagram of an application scenario of a mandrel assembly provided by an embodiment of the present invention, in which the mandrel assembly passes through a tortuous blood vessel and is cut from an expanded body by a tube, and a microcatheter and a target object are omitted in the diagram;

[0032] Figure 7 This is a schematic diagram of the shape of the cutting hole on the pipe when the self-expanding body of the mandrel assembly provided by one embodiment of the present invention is cut from the pipe

[0033] Figure 8 is a cross-sectional view of a self-expanding body of a mandrel assembly provided by an embodiment of the present invention;

[0034] Fig. 9 is a planar unfolded schematic diagram of a self-expanding body of a mandrel assembly provided by an embodiment of the present invention, wherein only a partial structure of the self-expanding body is shown in the figure;

[0035] Fig.10 It is a schematic structural diagram of a self-expanding support rod of a core shaft assembly provided according to one embodiment of the present invention.

[0036] [Description of reference numerals is as follows]:

[0037] 100-mandrel assembly, 1000-mandrel body, 1100-inner core, 1200-spring, 2000-preload assembly, 2100-self-expanding body, 2110-support rod, 2111-first segment, 2112-second segment, 2113-third segment, 2101-mesh, 2200-limiting piece, 200-microcatheter, 10-target object. DETAILED DESCRIPTION

[0038] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the present embodiment only illustrate the basic concept of the present invention in a schematic manner, and only the components related to the present invention are shown in the figure instead of being drawn according to the number, shape and size of the components in the actual implementation. The type, quantity and proportion of each component in the actual implementation can be a random change, and the component layout type may also be more complicated.

[0039] In addition, each embodiment of the following description has one or more technical features, but this does not mean that the user of the present invention must implement all the technical features in any embodiment at the same time, or can only implement part or all of the technical features in different embodiments separately. In other words, under the premise that implementation is possible, those skilled in the art can selectively implement part or all of the technical features in any embodiment according to the disclosure of the present invention and according to the design specifications or implementation requirements, or selectively implement a combination of part or all of the technical features in multiple embodiments, thereby increasing the flexibility of the implementation of the present invention.

[0040] As used in this specification, the singular forms "one", "an", and "the" include plural objects, and the plural form "a plurality" includes more than two objects, unless the content clearly indicates otherwise. As used in this specification, the term "or" is generally used in a sense that includes "and / or", unless the content clearly indicates otherwise, and the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium, and it can be a connection between two elements or an interactive relationship between two elements. Relational terms such as the terms "first", "second", etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor do they indicate or imply relative importance or implicitly indicate the number of technical features indicated. It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, 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. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] The terms "proximal end" and "distal end" used in this article are described from the relative positions and relative words of the various components of the medical device. Although not restrictive, generally the "distal end" is the end of the medical device that first enters the patient's body during normal use, and the "proximal end" is the end opposite to the "distal end", which is closer to the operator.

[0042] One of the purposes of the present invention is to provide a mandrel assembly, which is applied to a delivery mechanism and used to deliver and release a target object into a blood vessel. The mandrel assembly can improve the loading reliability of the target object in the delivery mechanism and reduce or even avoid the unloading accident of the target object.

[0043] In order to make the purpose, advantages and features of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings. It should be noted that the drawings are all in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. The same or similar reference numerals in the drawings represent the same or similar components.

[0044] Figure 1 FIG. 1 is a schematic diagram showing the structure of the mandrel assembly 100. Figure 1 As shown, the mandrel assembly 100 includes a mandrel body 1000 and a pre-tightening assembly 2000, and the pre-tightening assembly 2000 is arranged on the mandrel body 1000. The pre-tightening assembly 2000 includes a self-expanding structural member (not marked in the figure) and a stopper 2200. The self-expanding structural member has a radial expansion state and a radial contraction state. The proximal end of the self-expanding structural member remains relatively still with the mandrel body 1000, and the distal end of the self-expanding structural member can move along the axial direction of the mandrel 1000. By moving the distal end of the self-expanding structural member on the mandrel 1000, the self-expanding structural member can be switched between the radial expansion state and the radial contraction state. Specifically, when the distal end of the self-expanding structural member moves from the distal end to the proximal end, the self-expanding structural member switches from the radial contraction state to the radial expansion state, and when the distal end of the self-expanding structural member moves from the proximal end to the distal end, the self-expanding structural member switches from the radial expansion state to the radial contraction state. The limiting member 2200 is located on the distal side of the self-expanding structural member, and is used to limit the maximum distance that the distal end of the self-expanding structural member moves from the proximal end to the distal end, thereby limiting the minimum outer diameter of the self-expanding structural member. That is, when the distal end of the self-expanding structural member moves to abut against the limiting member 2200, the distal end of the self-expanding structural member cannot continue to move toward the distal end, which prevents the self-expanding structural member from continuing to contract radially, so that the outer diameter of the self-expanding structural member reaches the minimum value.

[0045] The mandrel assembly 100 is applied to a delivery mechanism, which is used to deliver and release the target object 10 at a target position in a target lumen. The target lumen is, for example, a blood vessel, and the target position is, for example, a position where an intracranial aneurysm occurs. Thus, the target object 10 may be a vascular implant, including but not limited to at least one of a vascular stent, a packing coil, and a hypotube.

[0046] Please refer to Figure 4, the conveying mechanism further includes a microcatheter 200. The core shaft assembly 100 is used to partially penetrate the lumen of the microcatheter 200, and the pre-tightening assembly 2000 is located in the lumen of the microcatheter 200. When the target object 10 is loaded by the conveying mechanism, the target object 10 is compressed in the microcatheter 200, and is sleeved on a portion of the outer circumference of the core shaft assembly 100, and the target object 10 wraps the pre-tightening assembly 2000. At the same time, the distal end of the self-expanding structural member abuts against the stopper 2200, and the self-expanding structural member applies a radially outward force to the target object. In an embodiment of the present invention, when the conveying mechanism is loaded with the target object 10, the self-expanding structural member is interference fit with the target object 10 to ensure that the self-expanding structural member can provide a radially outward force to the target object 10.

[0047] Continue to refer Figure 4 In actual application, the distal end of the microcatheter 200 is first transported to the target position of the target lumen, and then the target object 10 is sleeved on the outer peripheral surface of the distal end of the mandrel assembly 100, and the distal end of the mandrel assembly 100 is inserted into the microcatheter 200, and the target object 10 is pressed and gripped in the lumen of the microcatheter 100. Then, the mandrel assembly 100 is pushed in the direction from the proximal end to the distal end. Since the self-expanding structure applies a radially outward force to the target object 10, when the mandrel assembly 100 is pushed, a friction force is generated between the self-expanding structure and the target object, and the target object 10 moves synchronously from the proximal end to the distal end with the mandrel assembly 100 under the action of the friction force until it reaches the target site. Finally, the microcatheter 10 is withdrawn to release the target object 10 at the target site.

[0048] In the process of pushing the core shaft assembly 100, if the core shaft assembly 100 shakes or twists and there is a tendency for the distal end of the self-expanding structure to move, due to the existence of the limit member 2200, the distal end of the self-expanding structure can only move from the distal end to the proximal end and cannot move from the proximal end to the distal end, that is, the outer diameter of the self-expanding structure cannot be further reduced, which enables the self-expanding structure to always apply a radial outward force to the target object 10, effectively improving the loading reliability of the target object 10 and avoiding the target object 10 from being unloaded.

[0049] Furthermore, when releasing the target object 10, if the head end of the target object 10 fails to unfold or even fails to unfold or collapses, the expanded self-expanding structure can be used to apply a radial outward force to the target object 10 to push the target object 10 to fully unfold.

[0050] Generally, when the self-expanding structure is in the radial expansion state, its maximum outer diameter is smaller than the inner diameter of the target object 10 when it is fully expanded, but larger than the inner diameter of the target object 10 in the compressed state. In addition, by adjusting the distance between the proximal end of the stopper 2200 and the proximal end of the self-expanding structure, the minimum outer diameter of the self-expanding structure can be adjusted, thereby adjusting the magnitude of the radially outward force applied by the conveying mechanism of the self-expanding structure to the target object 10 when loading the target object. Generally, the distance from the proximal end of the stopper 2200 to the proximal end of the self-expanding structure is smaller than the length of the self-expanding structure when it is stretched into a straight shape. The "length" refers to the distance of the self-expanding structure in the axial direction of the core shaft body 1000, so that the self-expanding structure can apply a radially outward force to the target object 10. The “self-expandable structure is stretched into a straight shape” means that the self-expandable structure has a uniform inner diameter and a uniform outer diameter throughout its entire length.

[0051] Optionally, the mandrel assembly 100 includes a plurality of pre-tightening assemblies 2000, and all of the pre-tightening assemblies 2000 are sequentially arranged along the axial direction of the mandrel body 1100. In this way, when the axial length of the target object 10 is large and the conveying mechanism conveys the target object 10, the plurality of pre-tightening assemblies 2000 can apply radially outward forces to the target object 10 at different axial positions, further improving loading reliability and preventing the target object 10 from being unloaded. In some embodiments, a plurality of the pre-tensioning assemblies 2000 are arranged at intervals. In other embodiments, in two adjacent pre-tensioning assemblies 2000, the self-expanding structural member of the pre-tensioning assembly 2000 located on the distal side is adjacent to the limiting member 2200 of the pre-tensioning assembly 2000 located on the proximal side. In this case, the proximal end of the self-expanding structural member of the pre-tensioning assembly 2000 located on the distal side and the limiting member 2200 of the pre-tensioning assembly 2000 located on the proximal side may be connected by any suitable method including welding, bonding, hot melt connection, and interference fit, or may not be connected.

[0052] The self-expanding structural member includes a self-expanding body 2100, and the self-expanding body 2100 has the following characteristics: Figure 2 The radially expanded state shown and Figure 3The self-expanding body 2100 is in the radially expanded state, and the self-expanding structural member is also in the radially expanded state. When the self-expanding body 2100 is in the radially contracted state, the self-expanding structural member is also in the radially contracted state. The distal end of the self-expanding body 2100 is the distal end of the self-expanding structural member, and the proximal end of the self-expanding body 2100 is the proximal end of the self-expanding structural member. That is, by moving the distal end of the self-expanding body 2100, the self-expanding structural member switches between the radially expanded state and the radially contracted state.

[0053] It should be understood that the self-expanding body 2100 should be made of a material with high elasticity and is pre-shaped as follows: Figure 2 The self-expanding structure 2100 is in the radially expanded state shown. In this way, when the self-expanding structure is placed in the microcatheter 200 or wrapped by the target object 10, the self-expanding body 2100 is subjected to a force acting inwardly in the radial direction, so that the distal end of the self-expanding body 2100 moves from the proximal end to the distal end and switches to the radially contracted state. Conversely, when the self-expanding body 2100 is no longer subjected to a force acting inwardly in the radial direction, the distal end of the self-expanding body 2100 moves in the direction from the distal end to the proximal end under the action of its own elastic force. The material used to manufacture the self-expanding body 2100 is a material with shape memory properties, which can be a metal material or a polymer material. The optional metal material includes but is not limited to at least one of titanium, nickel-titanium alloy, stainless steel, platinum-tungsten alloy, platinum, platinum-iridium alloy, and cobalt-chromium alloy. The optional polymer material is, for example, a polymer elastomer.

[0054] In some embodiments, the self-expanding body 2100 is obtained by weaving wires and then pre-forming. In other embodiments, the self-expanding body 2100 is obtained by cutting a tube and then pre-forming. The pre-forming methods described herein include axial compression, heat treatment, bulging, and the like.

[0055] Compared with the braided structure, the self-expanding body 2100 obtained by cutting the tube has better performance.

[0056] Specifically, please refer to Figure 5When the self-expanding body 2100 includes a tubular mesh structure woven from filaments, when the tubular mesh structure passes through a tortuous blood vessel with a small radius of curvature, the braided wires on the small bend side of the tortuous blood vessel are stacked, which increases the difficulty of the conveying mechanism in turning. On the other hand, the stacked braided wires and the braided wires and the target object 10 are squeezed and rubbed against each other, thereby damaging the target object 10 and easily generating debris. Once the debris falls off and enters the blood vessel, it will cause thrombosis and other problems. As for the self-expanding body 2100 that is cut, the self-expanding body 2100 includes a plurality of support rods 2110 arranged around the core shaft body 1000. The plurality of support rods 2110 do not cross each other. Therefore, please refer to Figure 6 When the self-expanding body 2100 passes through a tortuous blood vessel with a small radius of curvature, the support rod 2110 can conform to the direction and shape of the blood vessel, and will not be stacked on the small bend side of the blood vessel. It is also beneficial to reduce the pushing resistance and improve the smoothness of delivery.

[0057] When the self-expanding body 2100 is cut from a tube, the embodiment of the present invention does not limit the shape of the cut mesh 2101. The mesh 2101 may be as follows: Figure 2 The elongated strip structure shown in Figure 7 The rhombus shown in a), the positive direction shown in b), the rectangle shown in c), the parallelogram shown in d), the circle shown in e), the ellipse shown in f), or the irregular shape shown in g). It should be noted that Figure 7 The shape of the mesh 2101 shown in the figure refers to the shape of the mesh 2101 when the self-expanding body 2100 is unfolded into a planar structure.

[0058] Next, the structure of the self-expanding body 2100 obtained by cutting is introduced in detail.

[0059] Please refer to Figure 2 , Figure 3 , Figures 8 to 10The self-expanding body 2100 includes a plurality of support rods 2110, a proximal retracting portion 2120 and a distal retracting portion 2130, and the plurality of support rods 2110 are arranged around the mandrel body 1000. The proximal retracting portion 2120 is sleeved on the mandrel body 1000 and fixedly connected to the mandrel body 1000, so that the proximal retracting portion 2120 and the mandrel body 1000 remain relatively stationary. The connection method between the proximal retracting portion 2120 and the mandrel body 1000 includes but is not limited to any one of welding, bonding, hot melt connection, and interference fit. The proximal retracting portion 2120 is also connected to the proximal ends of all the support rods 2110. The distal retracting portion 2130 is sleeved on the mandrel body 1000, and the distal retracting portion 2130 can move along the axial direction of the mandrel body 1000. The distal gathering portion 2130 is also connected to the distal ends of all the support rods 2110. That is, the proximal gathering portion 2120 constitutes the proximal end of the self-expanding body 2100 (or the proximal end of the self-expanding structural member), and the distal gathering portion 2130 constitutes the distal end of the self-expanding body 2100 (or the distal end of the self-expanding structural member).

[0060] The support rod 2110 includes a first segment 2111, a second segment 2112, and a third segment 2113 connected in sequence from the proximal end to the distal end, and the first segment 2111 and the third segment 2113 are symmetrical to each other. When the self-expanding body 2100 is in the radial expansion state, the distance from the second segment 2112 to the mandrel body 1000 is greater than the distance from the first segment 2111 to the mandrel body 1000. Since the distance from the proximal end of the stopper 2200 to the proximal end of the self-expanding structural member is less than the length of the self-expanding structural member when it is stretched into a straight line, in the embodiment of the present invention, when the self-expanding body 2100 is in the radial contraction state, the distance from the second segment 2112 to the mandrel body 1000 is also greater than the distance from the first segment 2111 to the mandrel body 1000. That is, the outer diameter of the self-expanding body 2100 at the second segment 2112 is greater than the outer diameter of the first segment 2111. The second segment 2112 is used to contact the target object 10 and provide a radially outward force to the target object 10. The first segment 2111 and the third segment 2113 are used to provide a radially outward support force to the second node 2112, so that the self-expanding body 2100 can expand radially.

[0061] The width B of the second segment 2112 is less than or equal to the width A of the first segment 2111, and "width" refers to the size of the corresponding segment in the circumferential direction of the mandrel body 1000. In some optional embodiments, the ratio of the width B of the second segment 2112 to the width A of the first segment 2111 is 0.3-1, and further, the ratio of the width B of the second segment 2112 to the width A of the first segment 2111 is 0.4-0.8. Such a size is convenient for cutting on the one hand, and on the other hand, the second segment 2112 with a smaller width can better conform to the shape of the tortuous blood vessel, which is conducive to improving the bending performance of the mandrel assembly 100.

[0062] In addition, the number of the support rods 2110 is set according to actual needs. Generally, the more the support rods 2110, the larger the contact area between the self-expanding body 2100 and the target object 10, and the greater the friction between the self-expanding body 2100 and the target object 10, and the loading reliability of the target object 10 is better and less likely to be unloaded. However, an excessive number of support rods 2110 increases the difficulty of cutting. The number of support rods 2110 is related to the diameter of the inner cavity of the catheter. Preferably, the number of support rods 2110 is shown in the following table:

[0063]

[0064] Furthermore, when the self-expanding body 2100 is in a radially expanded state, the ratio of the length D of the second segment 2112 to the length E of the self-expanding body 2100 is 0.1 to 1, and more preferably 0.1 to 0.5. Such a length setting can ensure that the self-expanding body 2100 is spherical or spindle-shaped after full expansion, which is beneficial to improving the bending ability of the mandrel assembly 100, and is also beneficial to promoting the deployment of the target object 10 when the target object 10 is released. "The length of the second segment 2112" refers to the size of the second segment 2112 in the axial direction of the mandrel body 1000, and "the length of the self-expanding body 2100" refers to the size of the self-expanding body 2100 in the axial direction of the mandrel body 1000.

[0065] In addition, in some optional embodiments, the self-expanding structure may further include a coating (not shown in the figure), which at least covers the inner surface and / or outer surface of the region of the self-expanding body 2100 corresponding to the second segment 2112, which can increase the contact area between the self-expanding structure and the target object 10, thereby increasing the friction between the self-expanding structure and the target object 10, and further improving the loading reliability of the target object 10. Of course, the coating may also be provided on the inner surface and / or outer surface of the region of the self-expanding body 2100 corresponding to the support rod 2110.

[0066] The coating material is a polymer material, specifically at least one of polyurethane (PU), polyethylene (PE), and expanded polytetrafluoroethylene (ePTFE).

[0067] In some optional embodiments, the self-expanding structure may further include a developing wire (not shown in the figure), which is wound on at least part of the outer surface of the self-expanding body 2100, and can play a developing role to assist in determining the position of the target object 10 in the target lumen. In addition, when the developing wire is wound on the outer surface of the self-expanding body 2100 corresponding to the area where the second segment 2112 is located, the friction between the self-expanding structure and the target object 10 can also be increased. The material of the developing wire includes but is not limited to at least one of platinum, iridium, tantalum, gold or other precious metal alloys.

[0068] Furthermore, the stopper 2200 is made of a developable material. That is, the stopper 2200 has developability. In this way, when the self-expanding structural member does not include the developing wire, the operator can determine the position of the target object 10 in the target lumen by observing the position of the stopper 2200 in the target lumen. Optional developing materials include but are not limited to at least one of platinum, iridium, tantalum, gold or other precious metal alloys. When the mandrel assembly 100 includes a plurality of the pre-tightening components 2000, the position of the target object 10 in the target lumen can be determined more accurately by developing the plurality of the stoppers 2200.

[0069] In addition, the mandrel body 1000 includes an inner core 1100 and a spring 1200, and the spring 1200 is sleeved on the outer circumference of the inner core 1100. The reason for this is that the diameter of the inner core 1100 is usually very small. If the preload assembly 2000 is directly set on the inner core 1100, on the one hand, the inner core 1100 is likely to damage the blood vessel wall, and on the other hand, the inner core 1100 is also likely to wear. On the other hand, the inner and outer diameters of the proximal contraction portion 2120 and the inner and outer diameters of the distal contraction portion 2130 are also very small. In other words, the inner and outer diameters of the pipe used to cut the self-expanding body 2100 are very small, which inevitably increases the difficulty of cutting. Even if the self-expanding body is braided, its braiding difficulty is very large.

[0070] In summary, the core shaft assembly provided in the embodiment of the present invention, by providing the limit member and making the limit member have a suitable distance from the proximal end of the self-expanding structure, can ensure that when the core shaft assembly is applied to a conveying mechanism and loaded with a target object, the self-expanding structure always applies a radially outward force to the target object, and no unloading situation due to the reduction of the outer diameter of the self-expanding structure occurs, thereby improving the loading reliability of the conveying mechanism for the target object.

[0071] A second object of the present invention is to provide a conveying mechanism, which is the aforementioned conveying mechanism.

[0072] The third object of the present invention is to provide a medical system, comprising the conveying mechanism and the target object 10. The target object 10 is configured to be able to expand or contract radially; the target object 10 is disposed in the microcatheter 200, and is sleeved on a portion of the outer circumference of the core shaft assembly 100, and covers the preload assembly 2000. The distal end of the self-expanding body 2100 abuts against the stopper 2200, and the self-expanding body 2100 applies a radially outward force to the target object 10.

[0073] As mentioned above, the target object 10 may include any one of a vascular stent, a packing coil, a hypotube, or a combination of two or more thereof. The embodiment of the present invention does not limit the material of the target object 10, which may be at least one of stainless steel, nickel-titanium alloy, cobalt-chromium alloy or polymer material.

[0074] Although the present invention is disclosed as above, it is not limited thereto. Those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A mandrel assembly, characterized in that: include: mandrel body; and, A preload assembly is arranged on the mandrel body and comprises a self-expanding structure and a stopper; the proximal end of the self-expanding structure remains relatively still with the mandrel body, and the distal end of the self-expanding structure can move along the axial direction of the mandrel body; the mandrel assembly is configured such that when the distal end of the self-expanding structure moves in the direction from the distal end to the proximal end, the self-expanding structure switches from a radially contracted state to a radially expanded state, and when the distal end of the self-expanding structure moves in the direction from the proximal end to the distal end, the self-expanding structure switches from a radially expanded state to a radially contracted state; The limiting member is located at the distal end side of the self-expanding structural member and is used to abut against the distal end of the self-expanding structural member to limit the maximum distance that the distal end of the self-expanding structural member moves from the proximal end to the distal end.

2. The mandrel assembly according to claim 1, characterized in that: The core shaft assembly includes a plurality of the pre-tightening components, and the plurality of the pre-tightening components are arranged in sequence along the axial direction of the core shaft body.

3. The mandrel assembly according to claim 1, characterized in that: The self-expanding structural member comprises a self-expanding body, and when the self-expanding body is in a radially contracted state, the self-expanding structural member is in a radially contracted state, and when the self-expanding body is in a radially expanded state, the self-expanding structural member is in a radially expanded state; The self-expanding body includes a proximal gathering portion, a distal gathering portion and a plurality of support rods. The proximal gathering portion is sleeved on the core shaft body and remains relatively stationary with respect to the core shaft body. The distal gathering portion is movably sleeved on the core shaft body. The plurality of support rods are arranged around the core shaft body, and the proximal ends of all the support rods are connected to the proximal gathering portion, and the distal ends of all the support rods are connected to the distal gathering portion.

4. The mandrel assembly according to claim 3, characterized in that: The support rod includes a first segment, a second segment and a third segment connected in sequence from the proximal end to the distal end, and the first segment and the third segment are symmetrical to each other; the distance from the second segment to the core shaft body is greater than the distance from the first segment to the core shaft body, and the ratio of the width of the first segment to the width of the second segment is 0.3 to 1.

5. The mandrel assembly according to claim 4, characterized in that: The ratio of the width of the first segment to the width of the second segment is 0.4 to 0.

8.

6. The mandrel assembly according to claim 3, characterized in that: The support rod includes a first segment, a second segment and a third segment which are connected in sequence from the proximal end to the distal end, and the first segment and the third segment are symmetrical to each other; the distance from the second segment to the core shaft body is greater than the distance from the first segment to the core shaft body; when the self-expanding body is in a radially expanded state, the ratio of the length of the second segment to the length of the self-expanding body is 0.1 to 1.

7. The mandrel assembly according to claim 6, characterized in that: When the self-expanding body is in a radially expanded state, the ratio of the length of the second segment to the length of the self-expanding body is 0.1 to 0.

5.

8. The mandrel assembly according to any one of claims 4 to 7, characterized in that: The self-expanding structure further includes a coating, which covers at least the outer surface and / or the inner surface of the region of the self-expanding body corresponding to the second segment.

9. The mandrel assembly according to claim 3, characterized in that: The self-expanding body is cut from a tube. When the inner diameter of the tube is 0.017 inch to 0.033 inch, the number of the support rods is 5 to 20.

10. The mandrel assembly according to claim 1, characterized in that: The self-expanding structural member comprises a self-expanding body, and when the self-expanding body is in a radially contracted state, the self-expanding structural member is in a radially contracted state, and when the self-expanding body is in a radially expanded state, the self-expanding structural member is in a radially expanded state; The self-expanding structural member further comprises a developing wire which is wound around at least a portion of the outer surface of the self-expanding body.

11. A conveying mechanism, characterized in that: It comprises a micro-catheter and a core shaft assembly as described in any one of claims 1 to 10, wherein the micro-catheter is used to be sleeved on a part of the outer circumference of the core shaft assembly and wrap the pre-tightening component.

12. A medical system, characterized in that: The invention comprises a target object and a delivery mechanism as claimed in claim 11, wherein the target object is configured to be able to expand or contract radially; the target object is arranged in the microcatheter and is sleeved on a part of the outer circumference of the core shaft assembly, and covers the pre-tightening component; the distal end of the self-expanding structural member abuts against the limiting member, The self-expanding structure applies a radially outward force to the target object.

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