Delivery device

Abstract

A delivery device (10), which is used for delivering a stent implant (2) in a catheter (3) and comprises a delivery guidewire (1) and a pushing element (12). The delivery guidewire (1) comprises a stent compression section (11) for loading the stent implant (2), and a proximal portion of the delivery guidewire (1) connected to the proximal end of the stent compression section (11). The pushing element (12) at least comprises a distal-end pushing element (121). The distal-end pushing element (121) is fixed on the stent compression section (11) and is arranged at a position other than the proximal end of the stent compression section (11). When the delivery device (10) delivers the stent implant (2) in the catheter (3) to the distal end, the distal-end pushing element (121) pulls the stent implant (2) distally so as to push same, so that the stent implant (2) is in an axially pulled state. Therefore, such a configuration converts the mode of pressing the stent implant (2) to push same into the mode of pulling the stent implant (2) to push same, thereby avoiding the problem of increased pushing resistance caused by increased radial support force of the stent implant (2) itself during the delivery, and further reducing the risk and difficulty of delivery.

Description

Conveying device Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a delivery device for delivering stent implants by pulling. Background Technology

[0002] Interventional neurology, also known as interventional neuroradiology or interventional neurosurgery, refers to the methodology of diagnosing and treating neurological diseases using interventional radiology methods. Interventional treatment of aneurysms has evolved from initial balloons and various types of detachable coils to various stents used for assisted embolization of wide-necked aneurysms, and finally to flow diverters (FDs), such as dense mesh stents and covered stents. With the development of interventional techniques and the widespread use of stent products, the efficacy of interventional treatment for intracranial aneurysms has greatly improved. Currently, the main stent techniques in clinical practice include stent-assisted coil embolization, flow diverter placement, and covered stent placement. During the placement of these stents, the performance of the delivery device has a significant impact on the difficulty and risk of delivery.

[0003] When treating intracranial aneurysms with endovascular stenting, the stent is delivered into the blood vessel via a guidewire. In existing technologies, most delivery methods involve assembling the stent onto a delivery wire and then attaching a metal flange or buckle to the proximal end of the stent to engage with anchor points on the stent; alternatively, a polymer component is placed at the proximal end of the stent for interference fit delivery. However, during delivery, the stent often experiences axial shortening due to thrust, leading to increased radial force within the delivery system and significantly increased pushing resistance, potentially even affecting stent placement.

[0004] It should be noted that the information disclosed in the background section of this application is intended to enhance the understanding of the general background of this application, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a delivery device that pushes a stent implant by pulling, so as to solve the problem in the prior art where the stent is squeezed as a whole during the process of pushing the stent to the lesion site, resulting in increased pushing resistance.

[0006] To address the aforementioned technical problems, this application provides a delivery device for delivering stent implants within a catheter, comprising a delivery guidewire and a pushing element; wherein:

[0007] The delivery guidewire includes: a stent compression section for loading the stent implant, and a proximal portion of the delivery guidewire connected to the proximal end of the stent compression section;

[0008] The pushing element includes at least a distal pushing element, which is fixed on the support compression section and disposed at a position other than the proximal end of the support compression section.

[0009] When the delivery device delivers the stent implant distally within the catheter, the distal pushing element can pull and push the stent implant distally, so that the stent implant is in a state of axial tension.

[0010] Optionally, when the distal pushing element engages with the engaging component of the stent implant, and the stent compression section is in a non-bent state, the distance from the distal end of the distal pushing element to the proximal end of the stent implant is L1, and the distance from the distal end of the distal pushing element to the distal end of the release imaging point on the proximal portion of the delivery guidewire is L2, where L1 ≤ L2, and L2 satisfies the following requirement:

[0011] d is the inner diameter of the catheter.

[0012] Optionally, when the distal pushing element engages with the engaging component of the stent implant and the stent compression section is in a bent state, the distance from the distal end of the distal pushing element to the distal end of the release imaging point is L2', where L1≤L2'.

[0013] Optionally, the diameter D of the compression section of the support meets the following requirements:

[0014] μ is the length coefficient, P is the actual pressure, E is the elastic modulus, I is the moment of inertia, and l is the length of the compression section of the support.

[0015] Optionally, when the delivery device delivers the stent implant distally within the catheter, the distal pushing element engages with the engaging component on the stent implant distally; when the delivery device delivers the stent implant proximally within the catheter, the distal pushing element engages with the engaging component on the stent implant proximally.

[0016] Optionally, the pushing element further includes a proximal pushing element, fixed to the support compression section and disposed at the proximal end of the support compression section;

[0017] When the delivery device retracts the stent implant proximally, the stent implant can be pulled and pushed proximally by the proximal pushing element.

[0018] Optionally, the length of the compression section of the stent is D1, and the distance between the distal end of the distal pushing element and the proximal end of the proximal pushing element is D2, where D1 > D2.

[0019] Optionally, the pushing element has a plurality of engaging slots distributed sequentially along its circumference, the engaging slots being used to engage with engaging components on the stent implant.

[0020] Optionally, the pushing element is a developable component, and / or the engaging groove is rectangular, arc-shaped, U-shaped, trapezoidal, or triangular.

[0021] Optionally, there may be multiple remote pushing elements, which are axially spaced and fixed to the compression section of the support.

[0022] The above-described delivery device, used for delivering a stent implant within a catheter, includes a delivery guidewire and a pushing element. The delivery guidewire includes a stent compression section for loading the stent implant and a proximal portion of the delivery guidewire connected to the proximal end of the stent compression section. The pushing element includes at least a distal pushing element, which is fixed to the stent compression section and positioned at a location other than the proximal end of the stent compression section. When the delivery device delivers the stent implant distally within the catheter, the distal pushing element can pull and push the stent implant distally, thereby placing the stent implant in an axially tensile state.

[0023] This configuration allows the stent implant to be pushed distally by a distal pushing element, thus changing the compression pushing method to a pulling pushing method. In this way, during the delivery of the stent implant distally, the stent implant is always in a tensile state rather than a compressive state. This reduces the pushing resistance of stent implants with a certain degree of shortening, and avoids the increase in pushing resistance caused by the increased radial support force of the stent implant during delivery, thereby reducing delivery risks and delivery difficulties.

[0024] In a further improvement, when the distal pushing element engages with the engaging component of the stent implant, considering the potential bending problem of the stent compression section, a lower limit for the size of L2 is defined, making... This ensures that the stent implant can be effectively pushed out in a pulling manner.

[0025] Further improvements considered potential stability issues in the stent compression section. Therefore, the diameter D of the stent compression section was limited. This method ensures the stability of the compression section of the stent.

[0026] Further improvements include setting multiple remote pushing elements. Multiple remote pushing elements can form a multi-point pushing mechanism, which can disperse the force points of the stent implant and further reduce the difficulty of pushing. Attached Figure Description

[0027] Those skilled in the art will understand that the accompanying drawings are provided to better understand this application and do not constitute any limitation on the scope of this application.

[0028] Figure 1 is a schematic diagram of the structure of a stent implant loaded in a catheter and pushed by a pushing element on a delivery device according to Embodiment 1 of this application.

[0029] Figure 2 is a structural relationship diagram between the pushing element and the stent implant when the delivery device retracts the stent implant proximally according to Embodiment 1 of this application.

[0030] Figure 3 is a structural relationship diagram between the pushing element and the stent implant when the delivery device pushes the stent implant to the distal end according to Embodiment 1 of this application.

[0031] Figure 4 is a force diagram of the slender rod in Embodiment 1 of this application.

[0032] Figure 5 is a diagram showing the state of the stent implant being pulled and pushed by the remote pushing element when the delivery device pushes the stent implant to the distal end in Embodiment 1 of this application.

[0033] Figure 6 is a diagram showing that when the delivery device pushes the stent implant to the distal end in Embodiment 1 of this application, the stent compression section on the delivery guide wire is under pressure and exhibits a certain degree of bending.

[0034] Figure 7 is a model diagram of the slender rod in Embodiment 1 of this application.

[0035] Figure 8 is a structural schematic diagram of the push element in Embodiment 2 of this application pushing the stent implant through an interference fit.

[0036] Figure 9 is a schematic diagram of the structure of setting the distal push element in the middle position of the stent implant according to Embodiment 3 of this application.

[0037] Figure 10 is a schematic diagram of the structure of a remote push element set at multiple locations in Embodiment 4 of this application.

[0038] Figure 11 is a schematic diagram of the structure of Embodiment 5 of this application, which only has a remote pushing element and no proximal pushing element.

[0039] Figure 12 is a schematic diagram of the push element of Embodiment 6 of this application engaging with the engaging component on the stent implant via the engaging groove.

[0040] Figure 13 is a schematic diagram of the engagement state of Embodiment 6 of this application using a 2-winding-2 configuration.

[0041] Figure 14 is a schematic diagram of the engagement state of Embodiment 6 of this application using 1 winding 2.

[0042] Figure 15 is a schematic diagram of the 3-winding-3 engagement state in Embodiment 6 of this application.

[0043] Figure 16 is a schematic diagram of the engagement state of the arc-shaped engagement groove in Embodiment 6 of this application.

[0044] Figure 17 is a schematic diagram of the engagement state of the U-shaped engagement groove in Embodiment 6 of this application.

[0045] Figure 18 is a schematic diagram of the engagement state of the trapezoidal engagement groove in Embodiment 6 of this application.

[0046] Figure 19 is a schematic diagram of the engagement state of the triangular engagement groove in Embodiment 6 of this application.

[0047] In the attached figures: 10-delivery device; 1-delivery guidewire; 11-stent compression section; 12-pushing element; 121-distal pushing element; 122-proximal pushing element; 123-locking groove; 2-stent implant; 21-locking component; 3-catheter; 4-tip imaging spring; 5-release imaging point. Detailed Implementation

[0048] To make the objectives, advantages, and features of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this application.

[0049] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include the plural objects, unless otherwise expressly stated. As used in this specification and the appended claims, the term “or” is generally used to include “and / or,” unless otherwise expressly stated. The term “a plurality” is generally used to include two or more, unless otherwise expressly stated. The term “several” is used to include one or more, unless otherwise expressly stated.

[0050] Furthermore, in the following description, for ease of description, the terms "distal" and "proximal" are used; "proximal" is the end closer to the medical device operator; "distal" is the end farther from the medical device operator. Additionally, numerous specific details are provided in the following description to offer a more thorough understanding of this application. However, it will be readily understood by those skilled in the art that this application can be implemented without one or more of these details. In other instances, to avoid confusion with this application, some technical features well-known in the art have not been described.

[0051] The term "catheter" in this manual refers to a medical device used in conjunction with the delivery device during surgery to deliver, withdraw, and release stent implants. Examples include microcatheters, guiding catheters, intermediate catheters, access catheters, and delivery sheaths of various sizes. For convenience, the term "catheter" is used throughout this manual.

[0052] The purpose of this application is to provide a delivery device that can be used with a catheter to deliver a stent implant. The delivery device pushes the stent implant in a pulling manner so that the stent implant is always in a tensile state rather than a compressive state during delivery. This can avoid the situation where the pushing resistance increases due to the increased radial support force of the stent implant itself during delivery, thereby reducing delivery risks and delivery difficulties.

[0053] The following description is in conjunction with the accompanying drawings.

[0054] Example 1

[0055] Please refer to Figures 1 to 3. In Embodiment 1 of this application, a delivery device 10 is provided, which includes: a delivery guide wire 1, the delivery guide wire 1 includes a stent compression section 11, and a proximal portion of the delivery guide wire connected to the proximal end of the stent compression section 11 (see the position indicated by arrow A), the stent compression section 11 is used to load the stent implant 2.

[0056] The conveying device 10 further includes a pushing element 12 fixed on the support compression section 11. In this embodiment, there are two pushing elements 12, specifically a distal pushing element 121 and a proximal pushing element 122 arranged axially spaced apart; the distal pushing element 121 is located at a position other than the proximal end of the support compression section 11; the proximal pushing element 122 is located at the proximal end of the support compression section 11, and is closer to the proximal end of the entire conveying device 10 than the distal pushing element 121.

[0057] In use, the delivery device 10 is movably inserted into the catheter 3 to deliver the stent implant 2. The stent implant 2 can be a cut stent or a braided stent. Specifically, both the stent implant 2 and the delivery device 10 are inserted into the catheter 3, and the stent implant 2 is gripped and mounted on the delivery device 10. Then, through the cooperation between the pushing element 12 and the stent implant 2, the stent implant 2 can be pushed and finally delivered to the target location in the body.

[0058] Research has shown that if the delivery guidewire 1 is provided with a proximal pushing element 122 only at the proximal end of the stent implant 2, and without a distal pushing element 121, the stent implant 2 will be compressed by the pushing force and shorten axially when the delivery device 10 delivers the stent implant 2 to the distal end. This will cause the stent implant 2 to expand outward in the radial direction, resulting in increased pushing resistance.

[0059] In this regard, this application provides a distal pushing element 121 at a location other than the proximal end of the stent implant 2. The distal pushing element 121 can change the delivery method from the original squeezing and pushing method to the pulling and pushing method.

[0060] Referring to Figure 3, when the delivery device 10 delivers the stent implant 2 distally within the catheter 3, the stent implant 2 can be pushed distally by the distal pushing element 121, so that the stent implant 2 is always under axial tension. Conversely, referring to Figure 2, in this embodiment, when the delivery device 10 retracts the stent implant 2 proximally, the stent implant 2 can be pushed proximally by the proximal pushing element 122, which can also keep the stent implant 2 under axial tension.

[0061] Therefore, regardless of whether the stent implant 2 is pushed distally or proximally, it is always under axial tension. This avoids the problem of increased pushing resistance caused by increased radial support force due to axial compression during stent implant 2 delivery. Specifically, in this embodiment, the cooperation and mutual assistance between the distal pushing element 121 and the proximal pushing element 122 enable the stent implant 2 to have good pushing performance, effectively reducing delivery difficulty and risks.

[0062] Furthermore, when the delivery device 10 delivers the stent implant 2 to the distal end within the catheter 3, the relationship between the pushing element 12 and the stent implant 2 is shown in Figure 3. Ideally, the stent implant 2 is only pushed by the distal pushing element 121, while the proximal pushing element 122 does not participate in applying force. This can better achieve the pushing of the stent implant 2 under tension.

[0063] Conversely, when the delivery device 10 retracts the stent implant 2 proximally, the relationship between the pushing element 12 and the stent implant 2 is shown in Figure 2. Ideally, the stent implant 2 is only pushed by the proximal pushing element 122, while the distal pushing element 121 does not participate in applying force, thereby realizing the retraction of the stent implant 2 under tension.

[0064] Referring again to Figure 2, in this embodiment, the length of the stent compression section 11 is D1, and the distance between the distal end of the distal pushing element 121 and the proximal end of the proximal pushing element 122 is D2. To ensure that the stent implant 2 is always under tension in the axial direction when pushed proximally or distally, D1 ≥ D2, and D1 > D2 is optional. Optionally, D1 and D2 are close in size, that is, the difference between D1 and D2 should not be too large to avoid an excessively large empty space when the user adjusts the position of the stent implant 2 in the catheter 3 by pushing and pulling.

[0065] Therefore, the main function of the distal pushing element 121 is to enable the ability to pull and push the stent implant 2 to the distal end. It can achieve the pushing by cooperating with the stent implant 2 through various measures, such as the optional cooperation methods such as locking and interference fit.

[0066] The proximal pushing element 122 is designed to pull the stent implant 2 back to the proximal end. It can also be pulled back by various means in conjunction with the stent implant 2, such as locking or interference fit.

[0067] The structure of the remote pushing element 121 may be the same as or different from that of the proximal pushing element 122.

[0068] In practice, the distal pushing element 121 can be set at the farthest end of the stent compression section 11 (close to the far end of the stent implant 2) or at any position between the farthest end and the near end of the stent compression section 11. In short, when the delivery device 10 pushes the stent implant 2 toward the far end, the distal pushing element 121 can push it in a pulling manner.

[0069] In this embodiment, there is only one distal pushing element 121 and one proximal pushing element 122. The distal pushing element 121 can be located at the farthest end of the stent compression section 11, i.e., near the distal end of the stent implant 2. It should be understood that the distal pushing element 121 can also be located in the middle of the stent compression section 11. The term "middle position" as used herein refers to any position between the distal and proximal ends of the stent compression section 11, and not specifically the center of the stent compression section 11.

[0070] Each push element 12 and the conveying guide wire 1 are separately manufactured and assembled. That is, after each push element 12 and the conveying guide wire 1 are manufactured, they are assembled to form the conveying device 10. The assembly connection method between the push element 12 and the conveying guide wire 1 is not limited. For example, the optional connection methods include glue bonding, soldering, laser welding, etc., as long as it can ensure that the push element 12 can be tightly connected to the conveying guide wire 1.

[0071] Any of the pushing elements 12 can be metal or polymer compound. The delivery guide wire 1 can be a commonly used guide wire material, such as nickel-titanium alloy, stainless steel, etc., and the specific material is not limited.

[0072] In this embodiment, any of the pushing elements 12 can push the stent implant 2 through a snap-fit ​​mechanism. Specifically, snap-fit ​​components 21 can be provided at the proximal end, distal end, or other positions of the stent implant 2. The distal pushing element 121 needs to be close to the proximal end of the corresponding snap-fit ​​component 21, and the proximal pushing element 122 needs to be close to the distal end of the corresponding snap-fit ​​component 21. With this configuration, the stent implant 2 can be pulled and pushed distally by the cooperation of the distal pushing element 121 and the snap-fit ​​component 21 on the stent implant 2. Conversely, the stent implant 2 can be pulled and pushed proximally by the cooperation of the proximal pushing element 122 and the snap-fit ​​component 21 on the stent implant 2.

[0073] It should also be noted that the size of the pushing element 12 must ensure that the engaging component 21 remains at one end of the pushing element 12 during the pushing process and cannot extend beyond the pushing element 12, so as to ensure that the pushing element 12 has the pushing capability. It can be understood that the catheter 3 can constrain the stent implant 2, so that the engaging component 21 on the stent implant 2 is firmly engaged with the pushing element 12.

[0074] The engaging component 21 can be of various engaging structures, and this application is not limited thereto. Optionally, the engaging component 21 is made of a reproducible material such as gold or platinum-iridium, so that the engaging component 21 also has a reproducible function.

[0075] Furthermore, research has found that the delivery guidewire 1 of neurointerventional products is usually less than 1 mm in diameter, and the design length of the stent compression section 11 is usually greater than 20 mm. Therefore, the diameter of the delivery guidewire 1 is much smaller than the length of the stent compression section 11. Thus, in some application scenarios, the stent compression section 11 can be considered as a slender rod.

[0076] Therefore, when the delivery device 10 pushes the stent implant 2, the stent compression section 11 is actually under pressure. Given that the stent compression section 11 is a slender rod, its stability under this pressure state needs to be considered. If the rod loses stability, it will buckle, which will prevent the distal pushing element 121 from pushing the stent implant 2 distally. Therefore, it is necessary to calculate the diameter of the delivery guide wire 1 to ensure that the delivery guide wire 1 can meet its pushing capacity.

[0077] The actual formula for calculating the critical value of slender rods is:

[0078] In equation (1): P crThe critical pressure is the pressure at which the guide wire 1 may undergo plastic deformation and become unable to return to its initial state during pushing. E is the elastic modulus, which is only related to the material itself; for example, the elastic modulus of 304 stainless steel is approximately 193 GPa. I is the moment of inertia (or moment of inertia), which is related to the cross-sectional shape and size of the rod. Since the guide wire 1 is typically a round rod structure, for a round rod… μ is the length coefficient, which is related to the compression method of the rod. For the conveying guide wire 1, its compression method is the same as that in Figure 4, so μ is taken as 0.5; l is the length of the compression section of the support.

[0079] Based on the actual push requirements, the actual stress values ​​P and P of the member can be determined. cr The relationship is as follows: P < P cr (2)

[0080] Combining equation (2) with equation (1), we can obtain:

[0081] In formula (3): D is the diameter of the guide wire of the compression section 11 of the support; P is the actual pressure value.

[0082] Therefore, in the actual design process, the core wire diameter of the support compression section 11 can be calculated based on formula (3) to ensure the stability of the support compression section 11.

[0083] On the other hand, based on the aforementioned requirement to pull the stent implant 2, there are also certain requirements for the size of the internal delivery guide wire 1 of the stent implant 2.

[0084] As shown in Figure 5, during the process of the delivery device 10 pushing the stent implant 2 to the distal end, it is necessary to ensure that the stent implant 2 is essentially under tension only under the push of the distal pushing element 121. For this purpose, it is necessary to satisfy L1≤L2 during the pushing process to ensure that the stent implant 2 is always under tension, rather than under axial compression. L1 is usually the distance from the distal end of the distal pushing element 121 to the proximal end of the stent implant 2. In this embodiment, L1 is the sum of the length of the stent compression section 11 and the length of the engaging member 21 at the proximal end of the stent implant 2.

[0085] As those skilled in the art will understand, a release imaging point 5 is typically provided at the distal end of the proximal portion of the delivery guidewire. To avoid axial compression of the stent implant 2, the proximal end of the stent implant 2 should avoid contact with the release imaging point 5 during delivery. Therefore, the distal pushing element 121 engages with the engaging component 21 of the stent implant 2, and the stent compression section 11 is in a non-bent state, with L1 ≤ L2. L2 is the distance from the distal end of the distal pushing element 121 to the distal end of the release imaging point 5. The release imaging point 5 is typically used to identify the proximal position of the stent implant 2. Generally, a tip imaging spring 4 is also present at the distal end of the delivery guidewire 1 to identify the distal position of the delivery guidewire 1.

[0086] Further research revealed that although the stent implant 2 is under tension during delivery, the stent compression section 11 may also be under compression, resulting in some bending. Since the release imaging point 5 is usually close to the inner diameter of the catheter 3, the extreme case of the stent compression section 11 after bending under compression is considered to be shown in Figure 6. Based on Figure 6, in the extreme case, the stent compression section 11 is close to the inner wall of the catheter 3 at the middle position, exhibiting a certain bending shape. At this time, to ensure that the stent implant 2 is always under tension, it is also necessary to ensure that L1≤L2', where L2' is the distance from the distal end of the distal pushing element 121 to the distal end of the release imaging point 5 when the stent compression section 11 bends.

[0087] Based on the above extreme cases, the calculation model described in Figure 7 can be obtained. In this calculation model, the arc represents the compression segment 11 of the support when it is bent. At this time, its arc length can be calculated by the following formula:

[0088] In equations (4) and (5): r is the radius of the arc; h is the arc height; s is the chord length; and C is the arc length.

[0089] Where h = d / 2, d is the inner diameter of catheter 3, and s = L1, substituting into equations (4) and (5), we can obtain:

[0090] That is, L2' needs to satisfy:

[0091] Therefore, in the actual design process, the specific position of the distal pushing element 7 can be further optimized according to the calculation formula (7) to ensure that the stent implant 2 is always in a tensile state during the distal pushing process.

[0092] For example, the resistance of the stent implant 2 during the process of pushing it to the distal end is 3N. The core wire of the stent compression section 11 is made of 304 stainless steel with L1 = 30mm. The length of the locking component 21 is very short and can be ignored. The inner diameter of the fitting catheter 3 is 2.0mm. Therefore, according to the above calculation formulas (3) and (7), it can be concluded that the diameter of the core wire of the designed stent compression section 11 needs to be greater than 0.219mm, and the distance L2' between the distal pushing element 121 and the release imaging point 5 needs to be greater than 30.09mm.

[0093] In summary, in Embodiment 1 of this application, the pusher element 121 can be used to push the stent implant 2, which can change the pushing method from compression to pulling. This can reduce the pushing resistance of the stent implant 2, which has a certain degree of shortening, thereby avoiding the situation where the pushing resistance of the stent implant 2 increases due to the increase of its own radial support force during the delivery process, and thus reducing the risk and difficulty of delivery.

[0094] Example 2

[0095] Please refer to Figure 8. The conveying device 10 provided in Embodiment 2 of this application has a basically the same structure as the conveying device 10 provided in Embodiment 1. The same parts will not be described again. The following only describes the differences.

[0096] As shown in Figure 8, unlike Embodiment 1, in the delivery device 10 provided in Embodiment 2 of this application, both the distal pushing element 121 and the proximal pushing element 122 are used for interference fit with the stent implant 2. During interference fit, the stent implant 2 may not have a locking component 21, allowing the proximal and distal ends of the stent implant 2 to directly interfere with the pushing element 12. In this case, the length of the stent compression section 11 is the total compression length of the stent implant 2 within the catheter 3. For example, the length of the stent compression section 11 is D1, and the distance between the distal end of the distal pushing element 121 and the proximal end of the proximal pushing element 122 is D2. Unlike Embodiment 1, in this embodiment, D1 can be greater than, equal to, or less than D2.

[0097] When the interference fit is used, the above calculation formulas (3) and (7) are also applicable to the conveying device 10 provided in Embodiment 2. Here, they will not be explained in detail.

[0098] In addition, to achieve an interference fit, any pushing element 12 can be a polymer or metal, such as silicone, TPU, stainless steel, gold, etc., and any pushing element 12 needs to have an interference fit with the stent implant 2 and the catheter 3. That is, the thickness of the stent implant 2 plus the outer diameter of the pushing element 12 needs to be greater than the inner diameter of the catheter 3 to ensure that the stent implant 2 is delivered smoothly.

[0099] In addition, regardless of whether it is a snap-fit ​​or an interference fit, the number of the distal push element 121 can be one, two, three or even more. Similarly, the number of the proximal push element 122 can also be one, two or more. Preferably, the proximal push element 122 is one.

[0100] When there are multiple distal pushing elements 121, the multiple distal pushing elements 121 are arranged sequentially at intervals in the axial direction. They can be arranged at equal or unequal distances. When the delivery device 10 pushes the stent implant 2 to the distal end, all the distal pushing elements 121 apply force to the stent implant 2 and push the stent implant 2 to the distal end in a pulling manner. This forms a multi-point pushing, which can disperse the force points of the stent implant 2 and reduce the difficulty of pushing.

[0101] Example 3

[0102] Please refer to Figure 9. The conveying device 10 provided in Embodiment 3 of this application has a basically the same structure as the conveying device 10 provided in Embodiment 1. The same parts will not be described again. The following only describes the differences.

[0103] As shown in Figure 9, unlike Embodiment 1, in the conveying device 10 provided in Embodiment 3 of this application, the remote pushing element 121 is set in the middle position of the support compression section 11, for example, at 1 / 2, 1 / 3, 1 / 4 or other positions of the support compression section 11, so that the same function can be achieved.

[0104] In this embodiment, when the delivery device 10 retracts the stent implant 2 proximally within the catheter 3, the distal pushing element 121 can also pull the stent implant 2 proximally. That is, the distal pushing element 121, together with the proximal pushing element 122, pulls the stent implant 2 proximally. Of course, in other embodiments, the distal pushing element 121 may only perform pulling and pushing in the distal direction.

[0105] In the specific embodiment depicted in Figure 9, the stent implant 2 has engaging components 21 at both the distal and proximal ends of the distal pushing element 121. This allows the distal pushing element 121 to engage with its distal engaging component 21 for distal pushing and to retract proximally. When pushing distally, the distal pushing element 121 preferably does not contact its proximal engaging component 21; similarly, when retracting proximally, the distal pushing element 121 preferably does not contact its distal engaging component 21. Alternatively, the stent implant 2 may have engaging components 21 only at the distal end of the distal pushing element 121.

[0106] Therefore, the position and number of the locking components 21 on the stent implant 2 can be adjusted and changed according to the situation of the distal pushing element 121, and are not limited to setting the locking components 21 at both ends of the stent implant 2.

[0107] Example 4

[0108] Please refer to Figure 10. The conveying device 10 provided in Embodiment 4 of this application has a basically the same structure as the conveying device 10 provided in Embodiment 3. The same parts will not be described again. The following only describes the differences.

[0109] As shown in Figure 10, unlike Embodiment 3, in the delivery device 10 provided in Embodiment 4 of this application, there are two distal pushing elements 121. One distal pushing element 121 is located at the farthest end of the stent compression section 11, and the other distal pushing element 121 is located at the middle position of the stent compression section 11. In this way, distal pushing elements 121 are provided at both the far end and the middle position of the stent implant 2, forming a multi-point pushing, which helps to reduce the difficulty of delivery.

[0110] Optionally, the proximal and distal ends of one of the distal push elements 121 in the middle position are respectively provided with the engaging component 21 of the stent implant 2, while the distal push element 121 at the farthest end may only be provided with the engaging component 21 of the stent implant 2 at its distal end, or it may be provided with the engaging component 21 of the stent implant 2 at both its proximal and distal ends.

[0111] Furthermore, when applying the above calculation formulas (3) and (7), the farthest push element 121 can be calculated and analyzed separately. The specific calculation method is basically the same as in Embodiment 1, and will not be described in detail hereafter.

[0112] Example 5

[0113] Please refer to Figure 11. The conveying device 10 provided in Embodiment 5 of this application has a basically the same structure as the conveying device 10 provided in the above embodiments. The same parts will not be described again. The following only describes the differences.

[0114] As shown in Figure 11, unlike the embodiments described above, the conveying device 10 provided in Embodiment 5 of this application only has a distal pushing element 121, without a proximal pushing element 122. In this case, the distal pushing element 121 can engage with its distal engaging component 21 to achieve a pulling and pushing motion towards the distal end, and it can also engage with its proximal engaging component 21 to achieve a pulling and retraction motion towards the proximal end. This structure is simpler, eliminating the need for a separate proximal pushing element 122.

[0115] In this embodiment, the distal pushing element 121 can be disposed not only at the farthest end of the support compression section 11, but also at the middle position of the support compression section 11, such as at 1 / 2, 1 / 3, or 1 / 4 of the length. It should also be understood that there can be one, two, or more distal pushing elements 121.

[0116] It should also be noted that, in the above embodiments, the engagement form of the remote pushing element 121 is not limited to the snap-fit ​​structure, but can also be an interference fit or other forms. This application does not impose any special restrictions on this.

[0117] The following section will further explain the interaction between the push element 12 and the stent implant 2.

[0118] Example 6

[0119] First, it should be noted that the conventional snap-fit ​​pushing method is as follows: the snap-fit ​​component 21 is pushed by the proximal pushing element 122 and the release developing point 5 together.

[0120] In the delivery device 10 provided in Embodiment 6 of this application, a simpler locking method is provided. Only the pushing element 12 needs to cooperate with the locking component 21 to realize the pushing and retraction of the stent implant 2.

[0121] As shown in Figures 12 to 19, the pushing element 12 itself has a plurality of engaging slots 123 arranged sequentially along its circumference. These engaging slots 123 can directly engage with the engaging component 21. Further, the pushing element 12 can be a developable component; optionally, the proximal pushing element 122 is a developable component. The following is an illustrative description.

[0122] In an exemplary embodiment provided in Figure 12, the plurality of engagement slots 123 are arranged in an S-shape in the circumferential direction of the push element 12. Each engagement slot 123 is generally rectangular and an engagement component 21 can be provided in each engagement slot 123. The engagement slots 123 and engagement components 21 are in a one-to-one corresponding relationship, so that "1 around 1" engagement can be achieved.

[0123] In some other exemplary embodiments provided in Figures 13 and 15, two or three engaging components 21 are provided in each engaging slot 123 so that the engaging slot 123 and the engaging components 21 have a one-to-many engagement relationship, thereby enabling "2 around 2" or "3 around 3" engagement.

[0124] In some other exemplary embodiments shown in Figure 14, different numbers of engaging components 21 are provided in each engaging slot 123. For example, some engaging slots 123 are provided with one engaging component 21, while adjacent engaging slots 123 are provided with two or more engaging components 21 to achieve "1 around 2" or other forms of engaging.

[0125] In summary, the specific locking method can be adjusted and varied according to the number of locking components 21 on the stent implant 2. For example, in this embodiment, for 6 locking components 21, there can be multiple locking methods as described above.

[0126] Furthermore, the engaging groove 123 can be in various shapes besides rectangular. For example, in Figures 16 to 19, the engaging groove 123 can also be arc-shaped, U-shaped, trapezoidal, or triangular. Regardless of the shape of the engaging groove 123, it can have various engaging forms.

[0127] In this embodiment, the various locking structures described above are particularly suitable for the proximal push element 122, so as to overcome the defects of conventional locking push methods and make the locking push structure simpler.

[0128] In summary, the delivery device 10 provided according to various embodiments of this application includes a delivery guidewire 1 and a pushing element 12. The delivery guidewire 1 includes a stent compression section 11 for loading the stent implant 2, and a proximal portion of the delivery guidewire 1 connected to the proximal end of the stent compression section 11. The pushing element 12 includes at least a distal pushing element 121, which is fixed to the stent compression section 11 and positioned at a location other than the proximal end of the stent compression section 11. Therefore, when the delivery device 10 delivers the stent implant 2 distally within the catheter 3, the distal pushing element 121 can pull the stent implant 2 distally, keeping the stent implant 2 under tension. This allows the present application to transform the compression pushing method into a pulling method, thereby reducing the pushing resistance of the stent implant 2, which has a certain degree of shortening, and preventing the increased pushing resistance due to the increased radial support force of the stent implant 2 during delivery, thus reducing delivery risk and difficulty.

[0129] Secondly, when the distal pushing element 121 engages with the engaging component 21 of the stent implant 2, considering the possibility of bending in the stent compression section 11, a lower limit is further defined for the distance (L2) from the distal end of the distal pushing element 121 to the distal end of the release imaging point 5 to ensure that the stent implant 2 can be effectively pushed in a pulling manner. In addition, considering potential stability issues with the stent compression section 11, a lower limit is set for the diameter (D) of the stent compression section 11 to ensure its stability.

[0130] The above embodiments provide a detailed description of how the stent implant 2 and the pushing element 12 work together. Of course, this application includes, but is not limited to, the working methods listed in the above embodiments. Any modifications made based on the connection methods provided in the above embodiments are within the scope of protection of this application. Those skilled in the art can apply the principles described in the above embodiments to other similar applications.

[0131] It should also be noted that the above-described embodiments can be combined with each other. The above description is only a description of preferred embodiments of this application and is not intended to limit the scope of this application in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of this application.

Claims

1. A delivery device for delivering a stent implant within a catheter, characterized in that, Includes a guide wire and a pushing element, wherein: The delivery guidewire includes: a stent compression section for loading the stent implant, and a proximal portion of the delivery guidewire connected to the proximal end of the stent compression section; The pushing element includes at least a distal pushing element, which is fixed on the support compression section and disposed at a position other than the proximal end of the support compression section. When the delivery device delivers the stent implant distally within the catheter, the distal pushing element can pull and push the stent implant distally, so that the stent implant is in a state of axial tension.

2. The delivery device of claim 1, wherein, When the distal pushing element engages with the engaging component of the stent implant, and the compressed section of the stent is in a non-bent state, the distance from the distal end of the distal pushing element to the proximal end of the stent implant is L1, and the distance from the distal end of the distal pushing element to the distal end of the release imaging point on the proximal portion of the delivery guidewire is L2, where L1 ≤ L2, and L2 satisfies the following requirement: d is the inner diameter of the catheter.

3. The delivery device of claim 2, wherein, When the distal pushing element engages with the engaging component of the stent implant, and the stent compression section is in a bent state, the distance from the distal end of the distal pushing element to the distal end of the release imaging point is L2', where L1≤L2'.

4. The delivery device of claim 1 or 2, wherein, The diameter D of the stent compression section satisfies the following requirement: μ is the length coefficient, P is the actual pressure, E is the elastic modulus, I is the moment of inertia, and l is the length of the compression section of the support.

5. The delivery device of claim 1 or 2, wherein, When the delivery device delivers the stent implant distally within the catheter, the distal pushing element engages with the engaging component on the stent implant distally; when the delivery device delivers the stent implant proximally within the catheter, the distal pushing element engages with the engaging component on the stent implant proximally.

6. The delivery device of claim 1 or 2, wherein, The pushing element further includes a proximal pushing element, which is fixed to the compression section of the stent and disposed at the proximal end of the compression section of the stent; When the delivery device retracts the stent implant proximally, the stent implant can be pulled and pushed proximally by the proximal pushing element.

7. The delivery device of claim 6, wherein, The length of the compression section of the stent is D1, and the distance between the distal end of the distal pushing element and the proximal end of the proximal pushing element is D2, where D1 > D2.

8. The delivery device of claim 1 or 2, wherein, The pushing element has a plurality of engaging slots distributed sequentially along its circumference, the engaging slots being used to engage with engaging components on the stent implant.

9. The delivery device of claim 8, wherein, The pushing element is a developable component, and / or the engaging groove is rectangular, arc-shaped, U-shaped, trapezoidal, or triangular.

10. The delivery device of claim 1 or 2, wherein, The number of the remote pushing elements is multiple, and the multiple remote pushing elements are axially spaced and fixed on the compression section of the bracket.

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