Support pushing device

Abstract

The utility model discloses a stent pushing device in the technical field of intravascular stent pushing. The stent pushing device comprises a conveying wire, a pusher and a buffer ring. The pusher is arranged at the far end of the conveying wire; the near end of the buffer ring sleeves the outer side of the pusher, the far end of the buffer ring is open, the interior of the buffer ring is hollow to form an internal space, and the internal space is used for accommodating the near end of the stent; the buffer ring comprises a first state in a folded state and a second state in an unfolded state, and the buffer ring can be pushed to the far end from the first state to be released to the second state; when the buffer ring is in the first state, the buffer ring forms a cylindrical folded state in the extension direction of the conveying wire towards the far end; and when the buffer ring is in the second state, the far end of the buffer ring is expanded to form an expanded state with a small near end and a large far end in the extension direction of the conveying wire to the far end. By arranging the buffer ring, the external expansion force of the stent near-end port located in the inner space can be gradually weakened when the stent near-end port is unfolded, and stimulation and damage of the stent near-end port to blood vessels are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of vascular stent pushing, in particular to a stent pushing device. Background Art

[0002] Stent implantation is a minimally invasive surgery performed within a blood vessel through vascular puncture, which requires the use of a vascular stent and its delivery system with precise dimensions, strong imaging properties, good flexibility, and high compliance.

[0003] Existing various stent pushing devices mainly focus on the release accuracy, release stability, and recyclability and repositionability of the stent, but they basically make no contribution to alleviating the stimulation of the blood vessel wall during stent release.

[0004] For example, US Patent No. US9439791B2 discloses a stent having a generally cylindrical body formed by a single braided nitinol wire. The distal and proximal ends of the stent include a plurality of rings, some of which include marker members for visualizing the position of the stent. In another embodiment, the aforementioned stent includes an internal flow turning layer.

[0005] In the prior art, when a vascular stent is fully released, the expansion force caused by the sudden change in diameter during the release process of the stent may cause a certain degree of damage to the blood vessel.

[0006] Therefore, it is desirable to design a stent pushing device with proximal protection, so that when the stent is finally released, the expansion force caused by the sudden change in the proximal diameter of the stent can be buffered and absorbed, thereby reducing the stimulation and damage to the blood vessel wall during stent release. Based on this, the utility model designs a stent pushing device with proximal protection to solve the above problems. Summary of the Utility Model

[0007] The purpose of the utility model is to provide a stent pushing device with proximal protection to solve the blood vessel stimulation and damage caused by the sudden change in the proximal diameter of the vascular stent during final release. In this solution, a buffer ring structure is arranged at the distal end of the pushing device. When the stent is released, the buffer ring can release and absorb part of the expansion force caused by the sudden change in the proximal diameter of the stent, thereby reducing the damage to the blood vessel during stent release.

[0008] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a stent pushing device, used for pushing and releasing the stent, including a conveying wire; a pusher, arranged at the distal end of the conveying wire; a buffer ring, the proximal end of which is sleeved on the outside of the pusher, the distal end of which is open, and the interior is hollow to form an internal space, and the internal space is used to accommodate the proximal end of the stent; the buffer ring includes a first state of a folded form and a second state of an expanded form, and the buffer ring can be pushed and released to the second state from the first state to the distal end; when the buffer ring is in the first state, the buffer ring forms a columnar folded form in the direction in which the conveying wire extends to the distal end; when the buffer ring is in the second state, the distal end of the buffer ring expands and expands to form an expanded form with a small proximal end and a large distal end in the direction in which the conveying wire extends to the distal end.

[0009] Furthermore, the unfolded form of the buffer ring is a variable diameter multi-stage structure, which includes a buffer ring fixing part, a first section of the buffer ring and a second section of the buffer ring. The buffer ring fixing part is fixedly sleeved on the outside of the pusher, the proximal end of the first section of the buffer ring is connected to the distal end of the buffer ring fixing part, and the proximal end of the second section of the buffer ring is connected to the distal end of the first section of the buffer ring.

[0010] Specifically, the diameter variation ranges of the first section of the buffer ring and the second section of the buffer ring are different.

[0011] In a further embodiment, the variable diameter multi-section structure also includes a third section of the buffer ring, the proximal end of the third section of the buffer ring is connected to the distal end of the second section of the buffer ring, and the diameter change amplitude of the third section of the buffer ring is less than or equal to the diameter change amplitude of the first section of the buffer ring.

[0012] In a further embodiment, when the buffer ring is in the second state, the proximal end and the distal end of the buffer ring form a unilateral expansion angle α, and the range of the unilateral expansion angle α is 8°<α<90°.

[0013] In a further embodiment, when the buffer ring is in the second state, the diameter D1 of the proximal end of the buffer ring ranges from 0.5 to 8.0 mm, the diameter D2 of the distal end of the buffer ring ranges from 0.8 to 20.0 mm, and the proximal diameter D1 and the distal diameter D2 of the buffer ring satisfy 2*D1≤D2≤4*D1.

[0014] In a further solution, the pusher includes a pusher head, a pusher middle and a pusher tail, one end of the pusher middle is connected to the pusher head, and the other end is connected to the pusher tail, the pusher tail is close to the pusher wire relative to the pusher head, and the pusher tail is fixedly connected to the pusher wire, the proximal end of the buffer ring is sleeved on the pusher tail, the length of the part of the buffer ring that can be folded or unfolded is the effective length L1 of the buffer ring, and the relationship between the sum of the lengths L2 of the pusher head and the middle of the pusher and the effective length L1 is L1>L2;

[0015] The relationship among the effective length L1 of the buffer ring, the proximal diameter D1, the distal diameter D2, and the unilateral expansion angle α of the buffer ring satisfies: L1 = max(5mm, 5 * D1).

[0016] In a further solution, the relationship among the outer diameter D3 of the pusher head, the outer diameter D4 of the middle part of the pusher, and the outer diameter D5 of the tail part of the pusher is: D4 < D3 < D5.

[0017] In a further solution, the connection mode between the pusher and the delivery wire includes gluing and / or welding and / or heat shrinkage; the pusher is selected as a radiopaque material.

[0018] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0019] (1) By arranging a buffer ring at the distal end of the pusher, when the buffer ring is retracted, it is a hollow cylindrical shape, and when it is expanded, it has a certain expansion angle and is a hollow horn-shaped structure with a small proximal end and a large distal end. The interior of the buffer ring is hollow to form an internal space, and the outside of the proximal end of the stent is located in the internal space of the buffer ring, so as to realize buffering for the release of the proximal end port of the stent. The buffer ring absorbs part of the expansion force caused by the sudden change in diameter of the stent, thereby reducing the damage to the blood vessel during the release of the stent. The buffer ring forms a complete circle of wrapping around the proximal end of the stent, which can uniformly restrict the release port of the proximal end of the stent, avoid uneven force affecting the release effect, and at the same time reduce the stimulation and damage of the proximal end port to the blood vessel during the release of the stent. When the stent is released, the buffer ring has a certain expansion angle with a small proximal end and a large distal end, which limits the expansion angle of the buffer ring, so that the buffer ring can maintain the required expansion angle under the impact of blood flow in the blood vessel, ensuring the buffering effect on the released stent.

[0020] (2) The buffer ring is a variable-diameter multi-segment structure, and the variable-diameter multi-segment structure includes at least two expansion parts with different diameter changes. When the stent is completely released, through the variable-diameter constraint of the buffer ring, the outward expansion force when the proximal end port of the stent expands is gradually weakened, reducing its stimulation and damage to the blood vessel.

[0021] (3) In the variable-diameter multi-segment structure, the first segment of the buffer ring is the first-level buffer area. While effectively releasing and opening the stent, it initially expands the proximal diameter of the stent, reducing the expansion potential energy of the stent; the second segment of the buffer ring is mainly used to buffer and absorb the kinetic energy generated when the stent expands in the first segment of the buffer ring; the third segment of the buffer ring is mainly used to effectively release and open the stent, gradually opening the proximal end of the stent, further reducing the potential energy of the stent, and stably releasing it in the blood vessel.

[0022] (4) The head, middle part, and tail part of the pusher are arranged in the retracted part space formed by the buffer ring. The stent shrinks and the proximal end is squeezed in the middle part of the pusher, increasing the anti-deployment property before the complete release of the stent, so that the stent and the stent delivery device are not easily deployed.

[0023] (5)The pusher is made of radio-opaque material. During the process of stent delivery and release, the pusher serves as a marker. When the stent needs to be repositioned, as long as it is observed that the head of the pusher has not been exposed outside the port of the catheter, the already released stent can still be retrieved back into the outer tube of the delivery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 Schematic diagram of the overall structure of the stent pusher device in an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the blood vessel when the stent of the present invention is fully released;

[0027] Figure 3 Schematic diagram of the stent of the present invention fully retracted into the blood vessel;

[0028] Figure 4 Schematic diagram of the buffer ring structure of the present invention;

[0029] Figure 5 Another schematic diagram of the buffer ring structure of the present invention;

[0030] Figure 6 Schematic diagram of the connection structure between the delivery wire and the pusher of the present invention;

[0031] Figure 7 Schematic diagram of the folding of the buffer ring of the present invention;

[0032] Figure 8 Schematic diagram of the structure of the buffer ring in another embodiment of the present invention;

[0033] Figure 9 Schematic diagram of the structure of the buffer ring in another embodiment of the present invention;

[0034] Figure 10 Schematic diagram of the structure of the buffer ring in another embodiment of the present invention.

[0035] In the drawings, the list of components represented by each reference numeral is as follows:

[0036] 1 - Delivery wire;

[0037] 2 - Pusher;

[0038] 21 - Pusher head, 22 - Middle part of pusher, 23 - Tail part of pusher;

[0039] 3 - Buffer ring;

[0040] 31 - Buffer ring fixing part, 32 - First section of buffer ring, 33 - Second section of buffer ring, 34 - Third section of buffer ring;

[0041] 4 - Outer tube of conveying system;

[0042] 5 - Bracket;

[0043] 6 - Blood vessel. Detailed implementation mode

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] In this article, the terms "proximal end" and "distal end" refer to the relative orientation, relative position, and direction of elements or actions relative to each other from the perspective of the operator using the medical device. Although "proximal end" and "distal end" are not restrictive, the "proximal end" generally refers to the end of the medical device close to the operator during normal operation, and the "distal end" generally refers to the end that first enters the patient's body.

[0046] In this article, the left side in each view direction is the proximal end, and the right side is the distal end. The following will describe each structure of the stent delivery device in detail.

[0047] Please refer to Figure 1-7 , the present invention provides a technical solution: This stent delivery device is used to push and release the stent 5, and includes a delivery wire 1, a pusher 2, and a buffer ring 3. The pusher 2 is arranged at the distal end of the delivery wire 1. The proximal end of the buffer ring 3 is sleeved outside the pusher 2 and fixedly connected to the pusher 2. The distal end of the buffer ring 3 is open. The buffer ring 3 extends distally along the axial direction of the delivery wire 1. The inside of the buffer ring 3 is hollow to form an internal space, and this internal space is used to accommodate the proximal end of the stent 5 to buffer the release of the proximal end port of the stent 5 when the stent 5 is released.

[0048] The buffer ring 3 includes a first state and a second state, and the buffer ring 3 can be pushed distally from the first state to be released to the second state; when the buffer ring 3 is in the first state, the buffer ring 3 is in a retracted form, and the buffer ring 3 forms a cylindrical retracted form in the direction of the distal extension of the delivery wire 1. The cylindrical retracted form has a hollow internal space for accommodating the proximal end of the stent 5; when the buffer ring 3 is in the second state, the buffer ring 3 is in an expanded form, and the distal end of the buffer ring 3 expands and forms an expanded form with a small proximal end and a large distal end in the direction of the distal extension of the delivery wire 1. The expanded form has an internal space with a small proximal end and a large distal end, forming a buffer for the release of the proximal end of the stent 5.

[0049] In this way, the buffer ring 3 forms a complete circle around the proximal end of the stent 5. Such a buffer ring 3 with an integral hollow annular structure can uniformly restrict the proximal end port of the stent 5 during the release of the stent 5, avoiding uneven force and affecting the release effect of the stent 5. At the same time, the expanded form of the buffer ring 3 has a small proximal end and a large distal end, which gives the buffer ring 3 a certain expansion angle and can maintain the required expansion angle under the impact of blood flow in the blood vessel, so as to slow down the opening speed of the proximal end port of the stent 5 in the internal space of the buffer ring 3, buffer and absorb the expansion force caused by the sudden change of the proximal end port during the release of the stent 5, thereby reducing the irritation and damage to the blood vessel caused by the proximal end port of the stent 5 during the release of the stent 5, and achieving the buffer effect during the release of the stent 5.

[0050] When the buffer ring 3 is in the second state, it is in an expanded form. As Figure 4 shown, the buffer ring 3 expands to form a trumpet-shaped structure with an expansion opening. The buffer ring 3 expands to present a frustum-shaped internal space with a gradually changing diameter. The internal space has a small proximal end and a large distal end, forming a certain expansion angle. When the buffer ring 3 is in the first state, the outer side of the buffer ring 3 is in a folded shape, which is a retracted form, forming a cylindrical internal space. The specific folding form is as Figure 7 shown. For the buffer ring 3, as Figure 7 shown in the left figure, the part of the expanded form that exceeds the proximal outer diameter in the radial direction is part A. After part A is folded circumferentially, the remaining part is part C. Part C continues to be folded circumferentially, thus forming the retracted form as Figure 7 shown in the right figure.

[0051] In this embodiment, the expanded form of the buffer ring 3 is a variable-diameter multi-segment structure. The variable-diameter multi-segment structure includes a buffer ring fixing part 31, a first buffer ring segment 32, and a second buffer ring segment 33. The buffer ring fixing part 31 is fixedly sleeved outside the pusher 2. The proximal end of the first buffer ring segment 32 is connected to the distal end of the buffer ring fixing part 31, and the proximal end of the second buffer ring segment 33 is connected to the distal end of the first buffer ring segment 32. The multi-segment variable-diameter structure is more conducive to the slow and gradual opening of the proximal end port of the stent during the release, gradually weakening the outward expansion force when the proximal end port of the stent expands, and reducing the irritation and damage to the blood vessel.

[0052] Preferably, the diameter variation range of the first buffer ring section 32 is different from that of the second buffer ring section 33. The diameter variation range here refers to the diameter variation between the proximal and distal ends, that is, the difference between the distal diameter and the proximal diameter of the first buffer ring section 32 is different from the difference between the distal diameter and the proximal diameter of the second buffer ring section 33, thereby forming gradually different buffering effects on the stent release.

[0053] Preferably, the diameter variation range of the first section 32 of the buffer ring is greater than or equal to the diameter variation range of the second section 33 of the buffer ring, so as to achieve a better buffering effect for the proximal release of the stent 5 .

[0054] Furthermore, if Figure 8 , 9 As shown, the diameter change rate of the first section 32 of the buffer ring can be fixed, can be changed evenly, or can be changed unevenly. Similarly, the diameter change rate of the second section 33 of the buffer ring can be fixed, can be changed evenly, or can be changed unevenly.

[0055] In one embodiment, the variable diameter multi-section structure also includes a buffer ring third section 34, the proximal end of the buffer ring third section 34 is connected to the distal end of the buffer ring second section 33, and the diameter change range of the buffer ring third section 34 is less than or equal to the diameter change range of the buffer ring first section 32.

[0056] The variable diameter multi-stage structure includes at least two expansion parts with varying diameters, such as the third section 34 of the buffer ring and the first section 32 of the buffer ring. When the buffer ring 3 is in the second state, the expansion part expands to an expanded form with a small proximal end and a large distal end and a varying diameter. When the buffer ring 3 is in the first state, the expansion part collapses to a cylindrical collapsed form.

[0057] In the variable diameter multi-stage structure, the buffer ring fixing portion 31 is used to connect and fix with the pusher 2; the first section 32 of the buffer ring is the first-level buffer zone, which effectively releases and opens the stent 5 while initially expanding the proximal diameter of the stent 5 to reduce the expansion potential energy of the stent 5; the second section 33 of the buffer ring is mainly used to buffer and absorb the kinetic energy generated by the stent 5 when the first section of the buffer ring expands; the third section 34 of the buffer ring is mainly used to effectively release and open the stent 5, so that the proximal end of the stent 5 is gradually opened, further reducing the potential energy of the stent 5, and stably releasing it into the blood vessel.

[0058] Furthermore, if Figure 5 , 10 As shown, the diameter change rate of the first section 32 of the buffer ring can be fixed, can be changed evenly, or can be changed unevenly. Similarly, the diameter change rate of the second section 33 of the buffer ring can be fixed, can be changed evenly, or can be changed unevenly; the diameter change rate of the third section 34 of the buffer ring can be fixed, can be changed evenly, or can be changed unevenly.

[0059] Preferably, the second section 33 of the buffer ring is arranged to be parallel to the central axis of the buffer ring 3 to extend the length of the buffer ring 3 while avoiding increasing the deployment angle, so as to achieve a better buffering effect for the proximal release of the stent 5 .

[0060] In this embodiment, when the support pushing device is used to push and release the support 5, as shown in FIG. Figure 3 As shown, the stent 5 needs to be transported to the human blood vessel in the outer tube 4 of the transport system. When the stent 5 is completely retracted in the outer tube 4 of the transport system, the buffer ring is in the first state of the retracted form, and the buffer ring 3 forms a cylindrical hollow retracted form in the direction of the transport wire 1 extending toward the distal end; Figure 2 As shown, when the bracket 5 is fully released, the buffer ring 3 is unfolded, and the structure of the buffer ring 3 includes a buffer ring fixing portion 31, a first section 32 of the buffer ring, a second section 33 of the buffer ring and a third section 34 of the buffer ring, forming a variable diameter multi-section structure. The first section 32 of the buffer ring and the third section 34 of the buffer ring are expansion portions, and the diameter change range is the same. The second section 33 of the buffer ring is arranged between the first section 32 of the buffer ring and the third section 34 of the buffer ring, and the diameter change range is smaller than the diameter change range of the first section 32 of the buffer ring and the third section 34 of the buffer ring, and is parallel to the central axis of the buffer ring 3.

[0061] Specifically, in the present embodiment, the variable diameter multi-stage structure is a curved surface structure, such as a conical surface structure. In the present embodiment, the variable diameter structure is a conical surface structure, and the diameter change rate is uniform, so that a stable buffer structure can be provided, and the stent 5 can be effectively released at the same time; in other embodiments, other curved surface structures can also be set, as long as the curved surface satisfies "the tangent line of any point on the axial section of the buffer ring 3 diffuses toward the distal end or is parallel to the axis along the axial direction of the conveying wire 1" in the second state. The second section 33 of the buffer ring of the variable diameter multi-stage structure is a hollow cylindrical section with a constant diameter, which connects two adjacent expansion sections, and the diameter change amplitude of the two expansion sections is the same, and the diameter change amplitude of the cylindrical section is smaller than that of the expansion section.

[0062] Specifically, in this embodiment, Figure 4 As shown, the proximal end and the distal end of the buffer ring 3 form a unilateral expansion angle α, and the range of the unilateral expansion angle α is 8°<α<90°, so as to buffer the release of the proximal end of the stent. The unilateral expansion angle α is set to be appropriate in the above angle range to avoid too large an angle reducing the buffering effect of the buffer ring 3, and too small an angle affecting or even limiting the release of the stent 5.

[0063] Preferably, the range of the unilateral deployment angle α is 15°≤α≤45°. Within this range, the deployed buffer ring can further effectively reduce the proximal release speed of the stent, achieve buffered release, and also avoid the stent from being unable to be fully released.

[0064] When the buffer ring 3 is in the second state, Figure 4 As shown, the multi-stage variable diameter structure forms a stepped circular ring structure, the first section 32 of the buffer ring and the third section 34 of the buffer ring are expansion parts with a certain expansion angle. In this embodiment, the unilateral expansion angle β1 of the first section 32 of the buffer ring is the same as the unilateral expansion angle β2 of the third section 34 of the buffer ring, and the second section 33 of the buffer ring is a hollow cylindrical section with a constant diameter.

[0065] Furthermore, when the buffer ring 3 is in the second state, the diameter D1 of the proximal end of the buffer ring 3 ranges from 0.5 to 8.0 mm, the diameter D2 of the distal end of the buffer ring 3 ranges from 0.8 to 20.0 mm, and the proximal diameter D1 and the distal diameter D2 of the buffer ring 3 satisfy 2*D1≤D2≤4*D1.

[0066] In this embodiment, if Figure 5 As shown, the pusher 2 includes a pusher head 21, a pusher middle part 22 and a pusher tail 23. One end of the pusher middle part 22 is connected to the pusher head 21, and the other end is connected to the pusher tail 23. The pusher tail 23 is close to the pushing wire 1 relative to the pusher head 21 and the pusher tail 23 is fixedly connected to the pushing wire 1. The proximal end of the buffer ring 3 is sleeved on the pusher tail 23.

[0067] The length of the part that the buffer ring 3 can be folded or unfolded is the effective length L1 of the buffer ring 3. The effective length L1 is greater than the sum of the lengths L2 of the pusher head 21 and the pusher middle part 22, that is, L1>L2. In this way, it can be ensured that the pusher head 21 and the pusher middle part 22 are located in the folding space to ensure that the buffer ring plays an effective buffering role when the bracket 6 is fully released.

[0068] Specifically, the effective length L1 of the buffer ring 3 satisfies: L1=(D2-D1) / 2(sin(α)). In this way, the effective length of the buffer ring 3 is appropriate, which can better achieve buffering for the stent release, effectively slow down the opening speed of the stent release port, and reduce stimulation to the blood vessel.

[0069] Specifically, the radial dimension of the pusher middle portion 22 is smaller than the radial dimension of the pusher head portion 21 and the radial dimension of the pusher tail portion 23 , and the pusher middle portion 22 is used to accommodate the proximal end of the limiting stent 5 .

[0070] The pusher head 21 and the middle part 22 of the pusher are located in the internal space formed by the buffer ring 3. The relationship among the outer diameter D3 of the pusher head 21, the outer diameter D4 of the middle part 22 of the pusher, and the outer diameter D5 of the pusher tail 23 is D4 < D3 < D5. Inside the internal space of the buffer ring 3, one end of the bracket 5 contracts at the middle part 22 of the pusher and is pressed against the pusher 2. The outer diameter of the pusher head 21 is larger than that of the middle part 22 of the pusher, so that the bracket 5 can be blocked by the pusher head 21 before being pushed and released completely, thereby increasing the anti-offloading property of the bracket 5 before complete release and making it not easy for the bracket 5 and the stent pushing device to produce offloading; while the outer diameter of the pusher head 21 is smaller than that of the pusher tail 23, which is more conducive to pushing and avoids the influence of the too large pusher head 21 on the pushing effect.

[0071] The buffer ring 3 and the pusher 2 are connected by means such as gluing, heat shrinking, and welding. The connection methods between the pusher 2 and the conveying wire 1 include gluing and / or welding and / or heat shrinking. The pusher 2 and the conveying wire 1 are connected to each other by welding, heat shrinking, a binder, or a similar bonding mechanism, which is convenient for fixing between the pusher 2 and the conveying wire 1.

[0072] In one embodiment, the pusher 2 is made of a radiopaque material, such as the material can be selected from lead, tungsten alloy, cobalt, etc. During the process of conveying and releasing the stent 5, the pusher 2 plays a marking role. When the stent 5 needs to be repositioned, as long as it is observed that the pusher head 21 has not been exposed outside the port of the outer tube 4 of the conveying system, the already released stent 5 can still be retrieved into the outer tube 4 of the conveying system.

[0073] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example 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 can be combined in a suitable manner in any one or more embodiments or examples.

[0074] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not elaborate on all details and do not limit the present invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the relevant art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A stent pushing device, used for pushing and releasing a stent, characterized in that: It includes a conveying wire (1); A pusher (2) is arranged at the distal end of the conveying wire (1); The buffer ring (3) has a proximal end sleeved on the outside of the pusher (2) and an open distal end, and is hollow inside to form an internal space, wherein the internal space is used to accommodate the proximal end of the stent; the buffer ring (3) comprises a first state of a folded form and a second state of an expanded form, and the buffer ring (3) can be pushed toward the distal end from the first state and released to the second state; when the buffer ring (3) is in the first state, the buffer ring (3) forms a cylindrical folded form in the direction in which the conveying wire (1) extends toward the distal end; when the buffer ring (3) is in the second state, the distal end of the buffer ring (3) expands and forms an expanded form in which the proximal end is small and the distal end is large in the direction in which the conveying wire (1) extends toward the distal end.

2. A bracket pushing device according to claim 1, characterized in that: The unfolded form of the buffer ring (3) is a variable diameter multi-section structure, which comprises a buffer ring fixing portion (31), a first buffer ring section (32) and a second buffer ring section (33). The buffer ring fixing portion (31) is fixedly sleeved on the outside of the pusher (2), the proximal end of the first buffer ring section (32) is connected to the distal end of the buffer ring fixing portion (31), and the proximal end of the second buffer ring section (33) is connected to the distal end of the first buffer ring section (32).

3. A bracket pushing device according to claim 2, characterized in that: The diameter variation ranges of the first section (32) of the buffer ring and the second section (33) of the buffer ring are different.

4. A bracket pushing device according to claim 3, characterized in that: The diameter variation range of the first section (32) of the buffer ring is greater than the diameter variation range of the second section (33) of the buffer ring.

5. A bracket pushing device according to claim 4, characterized in that: The variable diameter multi-section structure further comprises a third buffer ring section (34), the proximal end of the third buffer ring section (34) being connected to the distal end of the second buffer ring section (33), and the diameter variation range of the third buffer ring section (34) being less than or equal to the diameter variation range of the first buffer ring section (32).

6. A bracket pushing device according to claim 1, characterized in that: When the buffer ring (3) is in the second state, the proximal end and the distal end of the buffer ring (3) form a unilateral expansion angle α, and the range of the unilateral expansion angle α is 8°<α<90°.

7. A bracket pushing device according to claim 6, characterized in that: When the buffer ring (3) is in the second state, the diameter D1 of the proximal end of the buffer ring (3) ranges from 0.5 to 8.0 mm, the diameter D2 of the distal end of the buffer ring (3) ranges from 0.8 to 20.0 mm, and the proximal diameter D1 and the distal diameter D2 of the buffer ring (3) satisfy 2*D1≤D2≤4*D1.

8. A stent pushing device according to claim 7, wherein the pusher (2) comprises a pusher head (21), a pusher middle part (22) and a pusher tail part (23), wherein one end of the pusher middle part (22) is connected to the pusher head (21) and the other end is connected to the pusher tail part (23), the pusher tail part (23) is closer to the conveying wire (1) relative to the pusher head (21), and the pusher tail part (23) is fixedly connected to the conveying wire (1), the proximal end of the buffer ring (3) is sleeved on the pusher tail part (23), the length of the part of the buffer ring (3) that can be folded or unfolded is the effective length L1 of the buffer ring (3), and the sum of the lengths L2 of the pusher head (21) and the pusher middle part (22) and the effective length L1 is in the relationship of L1>L2; The relationship between the effective length L1 of the buffer ring (3) and the proximal diameter D1, the distal diameter D2, and the unilateral expansion angle α of the buffer ring (3) satisfies: L1=max(5mm, 5*D1).

9. A stent pushing device according to claim 8, wherein the relationship among the outer diameter D3 of the pusher head (21), the outer diameter D4 of the pusher middle (22) and the outer diameter D5 of the pusher tail (23) is D4<D3<D5.

10. A bracket pushing device according to claim 1, characterized in that: The pusher (2) and the conveying wire (1) are connected by gluing and / or welding and / or heat shrinking; The pusher (2) is made of radiopaque material.

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