A stent delivery system

Abstract

The present invention provides a stent delivery system, which relates to the technical field of medical devices. The stent delivery system includes an outer tube, an inner tube, a limiting assembly and a limiting line. The inner tube is arranged inside the outer tube, and a space for accommodating the stent is formed between the inner tube and the outer tube; the limiting assembly is sleeved on the outer periphery of the inner tube and is located between the inner tube and the outer tube. The outer peripheral surface of the limiting assembly is provided with a limiting groove for accommodating a developing component, and the interior of the limiting assembly is provided with a wire-passing hole; the limiting line is passed through the corresponding wire-passing hole, and the limiting line is used to restrain the proximal end of the stent so that the proximal end of the stent fits with the limiting assembly. By restraining the proximal end of the stent with the limiting line, the proximal end of the stent fits with the limiting assembly. Even after the outer tube is completely withdrawn, the proximal end of the stent is not instantly expanded under the cooperation of the limiting line and the limiting assembly, and the stent cannot pop forward, which effectively improves the accuracy of the stent release position.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a stent delivery system. Background Art

[0002] Peripheral artery stenosis or even occlusion is a pathological condition that leads to obstructed blood circulation, causing a series of symptoms such as limb movement disorders and pain. The current mainstream treatment method is to place stents in the lesion area through interventional surgery to expand the blood vessels. During the operation, the delivery system delivers the stent to the lesion area, releases the stent to allow it to expand and fit the blood vessel wall, expand the stenotic lesion site, and re-establish a smooth blood channel.

[0003] With the widespread application of peripheral arterial stent surgery, more and more technical problems have been discovered, and "forward jump" occurs when the stent is released. The main reason is that when the stent is to be fully released, the part of the stent that is deployed first will cause an instantaneous elastic force on the stent inside the tube, causing the stent to pop out to the distal end, causing vascular damage and inaccurate stent release position. Summary of the invention

[0004] The present invention provides a stent delivery system, which is used to solve the problem of inaccurate placement position of the existing stent.

[0005] The present invention provides a stent delivery system, comprising:

[0006] External pipe;

[0007] An inner tube is arranged inside the outer tube, and a space for accommodating a stent is formed between the inner tube and the outer tube;

[0008] A limit assembly is sleeved on the outer circumference of the inner tube and is located between the inner tube and the outer tube. The outer circumferential surface of the limit assembly is provided with a limit groove for accommodating the developing member, and the interior of the limit assembly is provided with a wire hole;

[0009] A limiting line is passed through the corresponding wire hole, and the limiting line is used to restrain the proximal end of the bracket so that the proximal end of the bracket fits with the limiting component.

[0010] A stent delivery system provided according to an embodiment of the present invention further includes:

[0011] A handle, the handle being connected to the outer tube and the limit line;

[0012] A tip is arranged at the distal end of the inner tube.

[0013] According to a stent delivery system provided by an embodiment of the present invention, the limiting assembly is provided with a plurality of the limiting grooves, and the plurality of the limiting grooves are arranged at intervals along the circumferential direction on the outer peripheral surface of the limiting assembly.

[0014] According to a stent delivery system provided by an embodiment of the present invention, the shape of the limiting groove is matched with the shape of the developing member, and the depth of the limiting groove is greater than the thickness of the developing member.

[0015] According to a stent delivery system provided by an embodiment of the present invention, the limiting assembly is provided with a plurality of groups of the wire passing holes, each group having two wire passing holes, the center line of one of the wire passing holes in the same group is coplanar with the side wall corresponding to one side of the limiting groove, and the center line of the other wire passing hole is coplanar with the side wall corresponding to the other side of the limiting groove.

[0016] According to a stent delivery system provided by an embodiment of the present invention, the limiting wire passes through one of the wire holes in the same group and passes around the proximal end of the stent toward the side of the outer tube and then passes through another wire hole.

[0017] A stent delivery system provided according to an embodiment of the present invention further includes:

[0018] A telescopic rod, the proximal end of which is connected to the handle, the distal end of which is passed through one of the wire holes in the same group, the distal end of the limit wire passes through another of the wire holes and bypasses the proximal end of the bracket toward one side of the outer tube and is then sleeved on the distal end of the telescopic rod.

[0019] According to a stent delivery system provided by an embodiment of the present invention, the distance between the wire hole and the central axis of the limiting assembly is smaller than the distance between the stent and the central axis.

[0020] According to a stent delivery system provided by an embodiment of the present invention, the limiting assembly comprises:

[0021] The limiting member body, a plurality of the limiting grooves are arranged at intervals along the circumferential direction on the outer peripheral surface of the limiting member body.

[0022] According to a stent delivery system provided by an embodiment of the present invention, the limiting assembly comprises:

[0023] Limiting member body;

[0024] A plurality of limit rods are arranged at intervals on the periphery of the central axis of the limit member body, the proximal ends of the limit rods are connected to the limit member body, and the limit rods are suitable for switching between an expanded state and a folded state. In the expanded state, the distal end of the limit rod is away from the central axis of the limit member body; in the folded state, the distal end of the limit rod is close to the central axis; the limit grooves are arranged one by one on the side of the limit rod away from the central axis, and the wire hole extends from the distal end of the limit rod to the proximal end of the limit member body.

[0025] The stent delivery system provided in the embodiment of the present invention constrains the proximal end of the stent by a limiting line so that the proximal end of the stent fits with the limiting assembly. Even after the outer tube is completely retracted, the proximal end of the stent is not expanded instantaneously due to the cooperation of the limiting line and the limiting assembly, and the stent cannot pop out forward, thereby effectively improving the accuracy of the stent release position. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 is a schematic side cross-sectional structural diagram of a stent delivery system provided by an embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of the three-dimensional structure of the stent delivery system provided by an embodiment of the present invention after the outer tube is removed;

[0029] Figure 3 yes Figure 2 A schematic diagram of the local enlarged structure at point A in the middle;

[0030] Figure 4 is a schematic diagram of the three-dimensional structure of the limiter body provided by an embodiment of the present invention;

[0031] Figure 5 is a schematic side structural diagram of a position limiting member body provided by an embodiment of the present invention;

[0032] Figure 6 is a schematic diagram of the main structure of the limiter body provided by an embodiment of the present invention;

[0033] Figure 7 It is one of the structural schematic diagrams of the limiting line and the limiting member body provided in the embodiment of the present invention;

[0034] Figure 8 is a schematic diagram of the three-dimensional structure of a stent delivery system provided by another specific embodiment of the present invention after removing the outer tube;

[0035] Fig. 9 yes Figure 8 A schematic diagram of the local enlarged structure at B in the middle;

[0036] Fig.10 This is the second structural schematic diagram of the limiting line and the limiting member body provided in the embodiment of the present invention;

[0037] Fig.11is a schematic diagram of the three-dimensional structure of a limit assembly provided by another embodiment of the present invention;

[0038] Fig.12 is one of the structural schematic diagrams of a limit assembly in an unfolded state provided by another embodiment of the present invention;

[0039] Fig.13 It is a schematic diagram of the main structure of a limit assembly in an unfolded state provided by another embodiment of the present invention.

[0040] Reference numerals:

[0041] 10. Outer tube; 20. Inner tube; 30. Limiting assembly; 31. Limiting groove; 32. Wire hole; 33. Limiting member body; 34. Limiting rod; 40. Limiting wire; 41. Ring; 50. Tip; 60. Bracket; 61. Developing member; 70. Telescopic rod. DETAILED DESCRIPTION

[0042] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0043] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0044] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" 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 a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0045] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0046] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0047] Combine the following Figure 1-Figure 13 The specific structure and use method of the stent delivery system according to the embodiment of the present invention are described.

[0048] like Figures 1 to 3 As shown, the stent delivery system includes an outer tube 10, an inner tube 20, a limiting assembly 30 and a limiting wire 40. The inner tube 20 is arranged inside the outer tube 10, and a space for accommodating the stent 60 is formed between the inner tube 20 and the outer tube 10. The limiting assembly 30 is sleeved on the outer circumference of the inner tube 20 and is located between the inner tube 20 and the outer tube 10. The outer circumferential surface of the limiting assembly 30 is provided with a limiting groove 31 for accommodating the developer 61, and the inside of the limiting assembly 30 is provided with a wire hole 32. The limiting wire 40 is passed through the corresponding wire hole 32, and the limiting wire 40 is used to restrain the proximal end of the stent 60 so that the proximal end of the stent 60 fits with the limiting assembly 30.

[0049] The stent delivery system provided in the embodiment of the present invention constrains the proximal end of the stent 60 by the limiting line 40 so that the proximal end of the stent 60 is in contact with the limiting assembly 30. Even after the outer tube 10 is completely retracted, the proximal end of the stent 60 is not expanded instantaneously due to the cooperation of the limiting line 40 and the limiting assembly 30, and the stent 60 cannot pop out forward, thereby effectively improving the accuracy of the release position of the stent 60.

[0050] In one embodiment of the present invention, the inner tube 20 is disposed inside the outer tube 10 , the inner tube 20 and the outer tube 10 are coaxially disposed, and the width of the annular gap between the inner tube 20 and the outer tube 10 is greater than the thickness of the bracket 60 .

[0051] In one embodiment of the present invention, Figure 2 As shown, the stent delivery system also includes a handle (not shown), which is connected to the outer tube 10 and the limit line 40. Specifically, the handle is connected to the proximal end of the outer tube 10. For the limit line 40 provided with a ring 41, the proximal end of the limit line 40 is fixed to the handle. After the telescopic rod is withdrawn, the medical staff pulls the limit line to the proximal end by rotating the handle knob. For the limit line 40 not provided with a ring 41, the proximal end of the limit line 40 is also fixed to the handle. When in use, one of the limit lines 40 is cut off to release the stent 60, and the limit line 40 can be pulled out as a whole at the handle end.

[0052] In one embodiment of the present invention, Figure 2 As shown, the stent delivery system further includes a tip 50 , which is disposed at the distal end of the inner tube 20 . Specifically, a through hole or a blind hole is disposed inside the tip 50 , and the tip 50 is sleeved on the distal end of the inner tube 20 .

[0053] In a preferred embodiment of the present invention, Figure 1 As shown, the outer peripheral surface of the distal end of the tip 50 is a conical surface to reduce the resistance encountered by the tip 50 during movement and facilitate the movement of the tip 50 in the blood vessel. The outer peripheral surface of the proximal end of the tip 50 is also a conical surface so that the tip 50 can partially enter the outer tube 10, ensuring that the stent 60 is completely inside the outer tube 10 during the delivery process.

[0054] In one embodiment of the present invention, Figures 2 to 3 As shown, a through hole is provided inside the stop assembly 30 so that the stop assembly 30 can be sleeved on the outer periphery of the inner tube 20. The through hole is located at the center of the stop assembly 30, and the center line of the through hole is in the same straight line as the center axis of the stop assembly 30. The outer peripheral surface of the distal end of the stop assembly 30 is a cylindrical surface, so as to facilitate the setting of the stop groove 31; the outer peripheral surface of the proximal end of the stop assembly 30 is a conical surface, and the conical surface is provided at the proximal end of the stop assembly 30, which can provide guidance for the movement of the stop assembly 30 inside the outer tube 10 during assembly, so as to reduce the resistance encountered by the stop assembly 30 during the movement inside the outer tube 10.

[0055] It should be noted here that the connection method between the limit assembly 30 and the inner tube 20 can be fixed on the inner tube 20 by bonding, ultrasonic welding, etc. In order to ensure that the limit assembly 30 passes smoothly inside the outer tube 10, a certain gap is maintained between the limit assembly 30 and the inner wall of the outer tube 10.

[0056] In one embodiment of the present invention, Figure 1 As shown, the distance between the limiting assembly 30 and the tip 50 is greater than or equal to the length of the stent 60 , and during the transportation process, the stent 60 is in the space surrounded by the inner tube 20 , the outer tube 10 , the tip 50 and the limiting assembly 30 .

[0057] In one embodiment of the present invention, Figure 3 As shown, the limiting assembly 30 is provided with a plurality of limiting grooves 31, the number of the limiting grooves 31 is the same as the number of the developing member 61, and the plurality of limiting grooves 31 are arranged at intervals along the circumferential direction on the outer peripheral surface of the limiting assembly 30, and the positions of the limiting grooves 31 correspond to the positions of the limiting assembly 30 one by one. In this embodiment, four limiting grooves 31 are provided, and the four limiting grooves 31 are arranged symmetrically in pairs. Preferably, the distance between two adjacent limiting grooves 31 is equal, and the size of each limiting groove 31 is equal.

[0058] In one embodiment of the present invention, the shape of the limiting groove 31 matches the shape of the developing member 61 and is slightly larger than the size of the developing member 61. The limiting groove 31 is formed with an opening at the proximal end of the limiting assembly 30 so that the developing member 61 can be inserted into the limiting groove 31. The depth of the limiting groove 31 is greater than the thickness of the developing member 61, so that after the developing member 61 is inserted into the limiting groove 31, the limiting groove 31 will not be exposed, thereby preventing the developing member 61 from being exposed from the limiting groove 31 and rubbing against the inner wall of the outer tube 10.

[0059] In one embodiment of the present invention, Figures 4 to 6 As shown, the limiting groove 31 has two oppositely arranged side walls, and the limiting assembly 30 is provided with multiple groups of wire passing holes 32, each group has two wire passing holes 32, and the center line of one wire passing hole 32 in the same group is coplanar with the side wall on one side of the corresponding limiting groove 31, and the center line of the other wire passing hole 32 is coplanar with the side wall on the other side of the corresponding limiting groove 31.

[0060] In one embodiment of the present invention, Figures 4 to 6 As shown, the limiting assembly 30 is provided with a plurality of groups of wire holes 32, and the number of groups of the wire holes 32 is the same as the number of the limiting slots 31. In this embodiment, the limiting assembly 30 is provided with four groups of wire holes 32. Of course, the number of groups of the wire holes 32 is not limited thereto, and three, five or more groups may also be provided. Each group has two wire holes 32, and the two wire holes 32 are arranged at intervals. The two wire holes 32 are located on both sides of the corresponding limiting slot 31. The center line of one wire hole 32 in the same group is coplanar with the side wall on one side of the corresponding limiting slot 31, and the center line of the other wire hole 32 is coplanar with the side wall on the other side of the corresponding limiting slot 31. By arranging the wire holes 32 in this way, the limiting wire 40 can be located on both sides of the developing member 61 after passing through the wire holes 32, and the length of the limiting wire 40 wound around the developing member 61 can be ensured to be the shortest, so that the limiting wire 40 only needs to move a short distance to restrain the developing member 61.

[0061] In a preferred embodiment of the present invention, Figure 6 As shown, each wire hole 32 is located on a concentric circle, that is, the distance between each wire hole 32 and the central axis is equal. This ensures that when the same force is applied to the proximal end of each limit line 40, the force applied by the distal end of the limit line 40 on each developing member 61 is the same, ensuring that the bracket 60 is subjected to balanced force.

[0062] In a preferred embodiment of the present invention, the distance between the wire hole 32 and the central axis of the limiting assembly 30 is smaller than the distance between the bracket 60 and the central axis, ensuring that the wire hole 32 is located on the inner side of the bracket 60 .

[0063] In a preferred embodiment of the present invention, Figures 4 to 6 As shown, the limit assembly 30 includes a limiter body 33, a plurality of limit grooves 31 are arranged at intervals along the circumferential direction on the outer circumferential surface of the limiter body 33, and the limit grooves 31 are set on the cylindrical surface of the limiter body 33. The wire hole 32 runs through the limiter body 33, and the wire hole 32 is a straight hole to facilitate the limit wire 40 to pass through the wire hole 32. The material of the limiter body 33 is a medical polymer material such as HDPE, nylon, etc., and can also be nickel-titanium memory alloy, stainless steel, cobalt-chromium alloy or other metal materials.

[0064] It should be noted that the cross section of the limiter body 33 is circular. Of course, the cross section of the limiter body 33 may also be a regular polygon or other shapes.

[0065] In a preferred embodiment of the present invention, the limiting wire 40 passes through one wire hole 32 in the same group and passes through another wire hole 32 after passing around the proximal end of the stent 60 toward the side of the outer tube 10. Specifically, Figure 7 As shown, one end of the limiting wire 40 is passed through a wire hole 32 in the same group, and the other end of the limiting wire 40 is passed through another wire hole 32, so that a C-shaped wire loop is formed at the distal end of the limiting wire 40, and the wire loop is arranged on the developing member 61, specifically, the wire loop is arranged on the connecting rod of the developing member 61. The material of the limiting wire 40 can be ultra-high molecular polyethylene, stainless steel, nickel-titanium alloy, etc., and the weaving method can be single-strand or multi-strand. The distal end of the limiting wire 40 constrains the proximal end of the bracket 60, so that the proximal end of the bracket 60 cannot be unfolded, and the proximal end of the limiting wire 40 is fixed to the handle.

[0066] In a preferred embodiment of the present invention, Figure 3As shown, the developing member 61 is a developing ring, and a through hole is provided in the middle of the developing ring, and the through hole is used to set the developing point. In this embodiment, the developing ring is in a circular ring shape. Of course, the developing ring can also be a regular polygonal ring or other shapes. The developing ring is arranged at both ends of the bracket 60, and specifically, the developing ring is arranged at the peaks at both ends of the bracket 60, and the developing ring and the bracket 60 are integrally formed.

[0067] A developing point is arranged in the through hole of the developing ring, and the material of the developing point is a combination of one or more of tantalum, gold, and platinum. The apertures of the developing rings at both ends of the bracket 60 can be the same or different. In this embodiment, developing rings are arranged at the distal end and the proximal end of the bracket 60, respectively, and the four developing rings at the distal end are arranged at equal intervals along the circumference of the bracket 60; of course, the number of developing rings at the distal end is not limited to this, and three, five, six or more can also be set.

[0068] In a preferred embodiment of the present invention, the surface of the stent 60 is coated with an anticoagulant coating. By coating the surface of the stent 60 with the anticoagulant coating, the stent 60 can be prevented from coming into contact with blood and forming a thrombus on the surface of the stent 60.

[0069] Furthermore, the anticoagulant coating is a combination of one or more of a heparin coating, a phosphorylcholine coating, a polypeptide coating, and a nano coating.

[0070] How to use the stent delivery system:

[0071] Before use, the bracket 60 is pre-installed on the outer surface of the inner tube 20 between the tip 50 and the limiter body 33, and the developing part 61 at the proximal end of the bracket 60 is inserted into the corresponding limiter groove 31. The distal end of the limiter line 40 has bound the developing part 61 to ensure that the developing part 61 is in contact with the limiter groove 31.

[0072] The stent 60 is delivered to the diseased position of the blood vessel. When the outer tube 10 is withdrawn, the distal end of the stent 60 is unfolded and attached to the inner wall of the blood vessel. At this time, since the proximal end of the stent 60 is bound to the limiter body 33 by the limit line 40, the proximal end of the stent 60 is not unfolded; then the limit line 40 is withdrawn, and the proximal end of the stent 60 is detached from the limiter body 33 and unfolded freely until the entire stent 60 is completely attached to the blood vessel wall. Since the stent 60 is not instantly expanded and unfolded under the action of external force after the outer tube 10 is completely withdrawn, the stent 60 cannot pop forward, which effectively improves the accuracy of the release position of the stent 60.

[0073] In another specific embodiment of the present invention, Figures 8 to 10As shown, the stent delivery system includes an outer tube 10, an inner tube 20, a limit assembly 30, a limit line 40, a handle and a tip 50. The structures of the outer tube 10, the inner tube 20, the limit assembly 30, the limit line 40, the handle and the tip 50 in this embodiment are the same as those in the above-mentioned embodiments and will not be described in detail herein. The difference between this embodiment and the above-mentioned embodiment is that the stent delivery system of this embodiment also includes a telescopic rod 70. In addition, the way in which the limit line 40 is wrapped around the proximal end of the stent 60 toward the side of the outer tube 10 in this embodiment is also different.

[0074] In this embodiment, the proximal end of the telescopic rod 70 is connected to the handle. Specifically, a knob is provided on the handle. The proximal end of the telescopic rod 70 is connected to the knob. The knob is used to control a single or all telescopic rods 70 to move forward or backward. Four telescopic rods 70 are provided, and the four telescopic rods 70 correspond to four limit lines 40 one by one. The distal end of the telescopic rod 70 is passed through one of the wire holes 32 in the same group, and the distal end of the limit line 40 passes through another wire hole 32 and bypasses the proximal end of the bracket 60 toward one side of the outer tube 10 and is then sleeved on the distal end of the telescopic rod 70.

[0075] Furthermore, in order to conveniently sleeve the distal end of the limit wire 40 on the distal end of the telescopic rod 70, a ring 41 is provided at the distal end of the limit wire 40, and the inner diameter of the ring 41 is larger than the outer diameter of the wire hole 32. The distal end of the telescopic rod 70 passes through the ring 41 to bind the proximal end of the bracket 60 to the limiter body 33. When the telescopic rod 70 is withdrawn, the distal end of the telescopic rod 70 enters the wire hole 32, the ring 41 is separated from the distal end of the telescopic rod 70, and the proximal end of the bracket 60 is released.

[0076] Method of using the stent delivery system: When the outer tube 10 is retracted, the distal end of the stent 60 is unfolded and attached to the inner wall of the blood vessel. At this time, the proximal end of the stent 60 is still constrained by the limiting line 40 to the limiting component body 33. The telescopic rod 70 is controlled to retract at the same time by the handle, and the distal end of the telescopic rod 70 enters the wire hole 32. The ring 41 slides off the distal end of the telescopic rod 70, and the proximal end of the stent 60 is released. The proximal end of the stent 60 is unfolded and attached to the inner wall of the blood vessel.

[0077] In another specific embodiment of the present invention, Figures 11 to 13As shown, the stent delivery system includes an outer tube 10, an inner tube 20, a limit assembly 30, a limit line 40, a handle and a tip 50. The structures of the outer tube 10, inner tube 20, limit line 40, handle and tip 50 in this embodiment are the same as those in the above-mentioned embodiment and will not be described in detail here. The difference between this embodiment and the above-mentioned embodiment lies in that, in this embodiment, the limit assembly 30 includes a limit member body 33 and a plurality of limit rods 34, and the plurality of limit rods 34 are arranged at intervals on the periphery of the central axis of the limit member body 33, and the proximal end of the limit rod 34 is connected to the limit member body 33, and the limit rod 34 is suitable for switching between an expanded state and a folded state. In the expanded state, the distal end of the limit rod 34 is away from the central axis of the limit member body 33; in the folded state, the distal end of the limit rod 34 is close to the central axis, and at this time, the limit rod 34 and the limit member body 33 have the same shape and the same size; the limit groove 31 is arranged one by one on the side of the limit rod 34 away from the central axis, and the wire hole 32 extends from the distal end of the limit rod 34 to the proximal end of the limit member body 33, and the wire hole 32 forms a port at the distal end of the limit rod 34 and another port at the proximal end of the limit member body 33.

[0078] It should be noted that in this embodiment, the limiting assembly 30 includes four limiting rods 34 . Of course, the number of limiting rods 34 is not limited thereto, and three, five or more limiting rods 34 may also be provided, which is specifically determined according to the number of limiting slots 31 .

[0079] It should also be noted that, in the present embodiment, each limiting rod 34 is provided with one limiting slot 31 . Of course, when the number of limiting slots 31 is large, each limiting rod 34 may also be provided with two limiting slots 31 .

[0080] There are many ways to connect the proximal end of the limiting rod 34 to the limiting member body 33. For example, the proximal end of the limiting rod 34 and the limiting member body 33 are integrally formed, the proximal end of the limiting rod 34 can be bent, and the limiting rod 34 can be switched from a folded state to an extended state. Of course, the proximal end of the limiting rod 34 and the limiting member body 33 can also be connected in a hinged manner.

[0081] Furthermore, the cross-sectional shape of the limiting rod 34 is a part of a sector, and the cross-sectional dimensions of the four limiting rods 34 are equal. The side of the limiting rod 34 away from the central axis of the limiting member body 33 is an arc surface, and the curvature of the arc surface is the same as the curvature of the outer peripheral surface of the limiting member body 33, ensuring that the limiting rod 34 can maintain the same shape and size as the limiting member body 33 in the retracted state.

[0082] Since the limiting rod 34 can expand toward the outer periphery of the limiting member body 33, the radial force of the stent 60 during expansion can be reduced, thereby reducing damage to the blood vessel wall. When the limiting assembly 30 is in a retracted state inside the outer tube 10, the central axis of the limiting member body 33 is consistent with the central axis of the stent 60, the inner tube 20, and the outer tube 10, and the wire hole 32 of each limiting rod 34 is in a horizontal straight line state.

[0083] When the limit rods 34 are in the expanded state, the four limit rods 34 are arranged symmetrically about the central axis. The expansion degree of each limit rod 34 is the same, and an angle a is formed between the central axis and the limit rod 34. Preferably, the angle a is 25°-55°. In this embodiment, the material of the limit assembly 30 can be nickel-titanium alloy, stainless steel, or cobalt-chromium alloy.

[0084] Method of using the stent delivery system: During the retraction of the outer tube 10, the distal end of the stent 60 opens and expands onto the blood vessel wall; as the outer tube 10 is retracted to the distal end of the limiting rod 34, the limiting assembly 30 begins to unfold, at which time the limiting line 40 is restrained on the outside of the stent 60, and the proximal end of the stent 60 maintains the same shape as the limiting assembly 30, and then the limiting line 40 is retracted, at which time the stent 60 can be fully unfolded and attached to the blood vessel wall.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A stent delivery system, characterized in that: include: External pipe; An inner tube is arranged inside the outer tube, and a space for accommodating a stent is formed between the inner tube and the outer tube; A limit assembly is sleeved on the outer circumference of the inner tube and is located between the inner tube and the outer tube. The outer circumferential surface of the limit assembly is provided with a limit groove for accommodating the developing member. The interior of the limit assembly is provided with a wire hole. The outer circumferential surface of the proximal end of the limit assembly is a conical surface. A limiting wire is passed through the corresponding wire hole, and is used to restrain the proximal end of the stent so that the proximal end of the stent fits with the limiting assembly; The limiting assembly is provided with a plurality of the limiting grooves, and the plurality of the limiting grooves are arranged at intervals along the circumferential direction on the outer peripheral surface of the limiting assembly; The limiting assembly is provided with a plurality of groups of the wire-passing holes, each group having two wire-passing holes, the center line of one of the wire-passing holes in the same group being coplanar with the side wall corresponding to one side of the limiting groove, and the center line of another of the wire-passing holes being coplanar with the side wall corresponding to the other side of the limiting groove; the limiting wire passes through one of the wire-passing holes in the same group and passes around the proximal end of the stent toward the side of the outer tube, and then passes through another of the wire-passing holes; A handle, the handle being connected to the outer tube and the limit line; A telescopic rod, the proximal end of which is connected to the handle, the distal end of which is passed through one of the wire holes in the same group, the distal end of the limit wire passes through another of the wire holes and bypasses the proximal end of the bracket toward one side of the outer tube and is then sleeved on the distal end of the telescopic rod.

2. The stent delivery system according to claim 1, characterized in that: Also includes: A tip is arranged at the distal end of the inner tube.

3. The stent delivery system according to claim 2, characterized in that: The shape of the limiting groove is matched with the shape of the developing member, and the depth of the limiting groove is greater than the thickness of the developing member.

4. The stent delivery system according to any one of claims 1 to 3, characterized in that: The distance between the wire passing hole and the central axis of the limiting assembly is smaller than the distance between the bracket and the central axis of the limiting assembly.

5. The stent delivery system according to any one of claims 1 to 3, characterized in that: The limiting component comprises: The limiting member body, a plurality of the limiting grooves are arranged at intervals along the circumferential direction on the outer peripheral surface of the limiting member body.

6. The stent delivery system according to any one of claims 1 to 3, characterized in that: The limiting component comprises: Limiting member body; A plurality of limit rods are arranged at intervals on the periphery of the central axis of the limit member body, the proximal end of the limit rod is connected to the limit member body, and the limit rod is suitable for switching between an expanded state and a folded state. In the expanded state, the distal end of the limit rod is away from the central axis of the limit member body; in the folded state, the distal end of the limit rod is close to the central axis of the limit member body; the limit grooves are arranged one by one on the side of the limit rod away from the central axis of the limit member body, and the wire hole extends from the distal end of the limit rod to the proximal end of the limit member body.

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