A multistage progressive vascular covered stent radial contraction device and method thereof

Abstract

The present application relates to the technical field of blood vessel covered device, especially refers to a multi-stage progressive blood vessel covered stent radial contraction device and method thereof, which comprises a base, a supporting frame arranged on the base, a wave coil contraction mechanism movably arranged on the supporting frame, a control mechanism movably arranged on the supporting frame, and an operating handle movably arranged on the supporting frame; the wave coil contraction mechanism is arranged in a ring structure, and comprises a plurality of contraction blocks. The present application has novel structure, adopts integrated modular layout, and all mechanisms are arranged in a centralized manner relying on the supporting frame, so that the structure is compact and the equipment occupies small area; a single operating handle is used to centrally control all contraction blocks, independent adjustment of multiple components is cancelled, the operation process is simplified, and manual operation error is reduced; each contraction block is provided with independent stroke protection; the size of the hollow contraction channel can be adjusted by rotating the operating handle, so that different outer diameter covered stents can be adapted, and tooling needs to be frequently replaced.

Description

Technical Field

[0001] This invention relates to the field of vascular stent compression technology, and in particular to a multi-stage progressive vascular stent-covered radial contraction device and method thereof. Background Technology

[0002] In the manufacturing process of vascular interventional medical devices, before assembling nickel-titanium alloy + PTFE-coated vascular stents, radial compression must be performed to reduce their outer diameter before inserting them into the delivery sheath, thus enabling minimally invasive implantation. The outer PTFE coating of the stent is thin and easily damaged, and the metal skeleton is elastic and sensitive. The uniformity and gentleness of compression molding directly determine the yield of the finished product and the safety of clinical use. Compression tooling is the core assembly equipment for stent pre-compression production.

[0003] Existing vascular stent pre-compression technology has three major drawbacks: 1. Mechanical damage: Localized stress concentration in traditional three-grip tooling leads to film rupture; 2. Uneven compression: Manual operation can cause the stent to deform into an elliptical shape, resulting in poor adhesion to the vessel wall after intravascular release during the procedure; 3. Low efficiency: A single compression tightening takes 3 to 5 minutes and cannot be adapted to different sizes of vascular stents. Vascular stents in the diameter range of 6 to 40 mm require different tooling for compression.

[0004] In addition, existing hydraulic compression tooling has the risk of liquid contamination, and the temperature of heat shrink tooling can damage the support coating. Therefore, there is an urgent need for a radial shrinkage device that features a full-size film-coated support, multi-claw synchronous and uniform force application, independent shrinkage limit protection, segmented multi-stage progressive compression, simple and compact operation, and no risk of film contamination / coating damage. This device would solve the technical problems of high breakage rate, poor forming accuracy, low efficiency, and insufficient versatility of traditional tooling. Summary of the Invention

[0005] This invention addresses the problems of existing technologies by providing a multi-stage progressive radial contraction device and method for vascular covered stents. It features a novel structure with an integrated modular layout. All mechanisms are centrally arranged on a support frame, resulting in a compact structure and small footprint. A single operating handle centrally controls all contraction blocks, eliminating independent adjustment of multiple components, simplifying the operation process, and reducing human error. Each contraction block corresponds to a limit block, and each contraction block has independent stroke protection, preventing excessive local contraction that could lead to covered stent damage or stent deformation. The size of the hollow contraction channel can be adjusted by rotating the operating handle to accommodate covered stents of different outer diameters. One device is compatible with multiple product specifications, eliminating the need for frequent tooling changes.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention provides a multi-stage progressive vascular stent-covered radial contraction device, comprising a base, a support frame mounted on the base, a wave-shaped contraction mechanism movably mounted on the support frame, a control mechanism movably mounted on the support frame, and an operating handle movably mounted on the support frame. The wave-shaped contraction mechanism has a ring-shaped structure and includes multiple contraction blocks, which are evenly arranged circumferentially and enclose to form a hollow contraction channel. The control mechanism includes a drive wheel and multiple limiting blocks, each limiting block being connected to a corresponding contraction block and used to limit the minimum contraction stroke of the contraction block. The drive wheel is driven by multiple contraction blocks to synchronously drive all contraction blocks to move radially. The drive wheel is rotatably mounted on the support frame, and the operating handle is connected to the drive wheel. By driving the operating handle, the drive wheel is rotated, synchronously causing the multiple contraction blocks to contract or expand.

[0007] The transmission wheel has an annular rack portion along its circumference on its outer edge, and the shrink block has a straight rack portion that meshes with the annular rack portion on its side near the outer edge of the transmission wheel. The transmission wheel drives the shrink block to rotate by meshing with the straight rack portion of the shrink block through the annular rack portion.

[0008] The support frame is provided with a plurality of limiting grooves evenly arranged along its circumference. Each limiting groove corresponds to a limiting block, and the limiting block is slidably disposed in the limiting groove.

[0009] The limiting block and the shrinking block are detachably connected.

[0010] The shrink block includes a transmission component and a shrink component. The transmission component has a first insertion slot through it. The top end of the shrink component is provided with an insertion part that engages with the first insertion slot. The transmission component also has a second insertion slot through it for the limiting block to pass through. The first insertion slot and the second insertion slot are connected. The insertion part also has a third insertion slot through it for the limiting block to pass through. The second insertion slot and the third insertion slot are correspondingly provided. The limiting block is inserted into the second insertion slot and the third insertion slot.

[0011] The top of the plug-in part is provided with a first connecting hole, and the limiting block is provided with a second connecting hole, with the first connecting hole and the second connecting hole being provided in correspondence.

[0012] The material of the shrinking component is POM.

[0013] Preferably, the number of shrink blocks is 6 to 8.

[0014] Preferably, the number of limiting blocks is 6 to 8.

[0015] The present invention also provides a contraction control method based on the aforementioned multi-stage progressive vascular stent graft radial contraction device, which includes the following steps: Step S1, Pre-installation and positioning: Place the nickel-titanium alloy + PTFE covered vascular stent into the hollow contractile channel; Step S2, single-circle progressive contraction: Adjust the operating handle to drive the transmission wheel, which drives all the contraction blocks to synchronously and slowly contract radially, uniformly applying pressure to the single-circle segment of the vascular stent to complete the initial compression, and push the compressed stent segment into the matching contraction sheath. Step S3, Segmented Multi-Level Repetition: Adjust the opening of the operating handle and perform synchronous radial contraction on the residual wave loop of the vascular stent segment by segment. After each segment of compression is completed, push in the sheath. Step S4, Fine-tuning and calibration: After all the wave loops have shrunk, adjust the operating handle to fine-tune the local shrinkage size so that the vascular stent as a whole maintains its roundness.

[0016] The beneficial effects of this invention are: This invention features a novel structure and an integrated modular layout. All mechanisms are centrally arranged on a support frame, resulting in a compact structure and small footprint. A single operating handle centrally controls all shrink blocks, eliminating the need for independent adjustment of multiple components, simplifying the operation process, and reducing human error. Each limit block corresponds to a shrink block, and each shrink block has independent travel protection to prevent excessive local shrinkage that could lead to film damage or support deformation. The size of the hollow shrink channel can be adjusted by rotating the operating handle to accommodate film supports of different outer diameters. One set of equipment is compatible with multiple product specifications, eliminating the need for frequent tooling changes. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a multi-stage progressive vascular stent radial contraction device according to the present invention.

[0018] Figure 2 This is a schematic diagram of the radial contraction device of a multi-stage progressive vascular stent graft according to the present invention from another perspective.

[0019] Figure 3 This is a partial internal structure schematic diagram of a multi-stage progressive vascular stent radial contraction device according to the present invention.

[0020] Figure 4 This is a schematic diagram of the structure of the shrink block of the present invention.

[0021] Figure 5 This is a schematic diagram of the shrink block of the present invention from another perspective.

[0022] Figure 6 This is an exploded view of the structure of the shrink block of the present invention.

[0023] exist Figures 1 to 6 The reference numerals in the figures include: 1. Base; 2. Support frame; 3. Operating handle; 4. Control mechanism; 5. Shrink block; 6. Hollow shrink channel; 7. Limiting block; 8. Transmission wheel; 9. Annular rack; 10. Linear rack; 11. Limiting groove; 12. Transmission component; 13. Shrinking component; 14. First insertion groove; 15. Insertion part; 16. Second insertion groove; 17. Third insertion groove; 18. First connecting hole; 19. Second connecting hole. Detailed Implementation

[0024] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention. The present invention will be described in detail below with reference to the accompanying drawings.

[0025] Example 1 The multi-stage progressive vascular covered stent radial shrinkage device of Embodiment 1 of this application, such as Figures 1 to 6As shown, it includes a base 1, a support frame 2 mounted on the base 1, a wave-shaped shrinking mechanism movably mounted on the support frame 2, a control mechanism 4 movably mounted on the support frame 2, and an operating handle 3 movably mounted on the support frame 2. The wave-shaped shrinking mechanism has a ring structure and includes multiple shrinking blocks 5. The multiple shrinking blocks 5 are evenly arranged circumferentially and enclose to form a hollow shrinking channel 6. The control mechanism 4 includes a transmission wheel 8 and multiple limiting blocks 7. The limiting blocks 7 are connected to the shrinking blocks 5 one-to-one and are used to limit the minimum shrinking stroke of the shrinking blocks 5. The transmission wheel 8 is driven by the multiple shrinking blocks 5 to synchronously drive all shrinking blocks 5 to move radially. The transmission wheel 8 is rotatably mounted on the support frame 2. The operating handle 3 is connected to the transmission wheel 8. By driving the operating handle 3, the transmission wheel 8 is driven to rotate, which synchronously drives the multiple shrinking blocks 5 to close or open. Preferably, the number of contraction blocks 5 is 6 to 8, and the number of limiting blocks 7 is 6 to 8; wherein, the contraction blocks 5 are irregularly shaped. Specifically, the embodiment of this application has a novel structure. The embodiment of this application uses a base 1 to support the entire equipment device, and a support frame 2 to provide an installation benchmark and support for all motion mechanisms. Multiple contraction blocks 5 arranged in a ring surround a hollow channel through which the vascular covered stent passes. The control mechanism 4 is composed of a transmission wheel 8 and a limiting block 7, serving as a power transfer and stroke constraint component. The operating handle 3 serves as a manual input actuator. By pulling or rotating the handle, the transmission wheel 8 is driven to rotate, and the transmission wheel 8 synchronously drives all contraction blocks 5 to synchronously retract or expand radially. The limiting block 7 matches the contraction block 5 one-to-one, limiting the extreme position of the inward movement of the contraction block 5 and preventing excessive compression of the stent. When the embodiment of this application is working, the vascular covered stent is placed, and the position of the operating handle 3 is adjusted so that the vascular covered stent slowly contracts in one turn and is inserted into the contraction sheath from the other end.

[0026] The embodiments of this application feature a novel structure and an integrated modular layout. All mechanisms are centrally arranged on the support frame 2, resulting in a compact structure and small equipment footprint. A single operating handle 3 centrally controls all shrink blocks 5, eliminating the need for independent adjustment of multiple components, simplifying the operation process, and reducing human error. Limiting blocks 7 correspond one-to-one with shrink blocks 5, and each shrink block 5 has independent stroke protection to prevent excessive local shrinkage that could lead to film damage or bracket deformation. The size of the hollow shrink channel 6 can be adjusted by rotating the operating handle 3 to accommodate film brackets of different outer diameters. One set of equipment is compatible with multiple product specifications, eliminating the need for frequent tooling changes.

[0027] In this embodiment, pre-installation and positioning are achieved by placing the nickel-titanium alloy + PTFE-coated vascular stent in the hollow contraction channel 6, ensuring that the stent and the contraction channel are coaxial. The operating handle 3 drives the transmission wheel 8, which drives all the contraction blocks 5 to synchronously and slowly retract radially, uniformly applying pressure to the single wave coil segment of the stent to complete the initial compression. The compressed stent segment is then pushed into the matching contraction sheath. The handle opening is adjusted to perform synchronous radial contraction on the remaining wave coil segments of the stent in sequence. After each segment is compressed, it is pushed into the sheath. After all wave coils have been contracted, the operating handle 3 can be slightly adjusted to fine-tune the local contraction size to ensure the overall roundness of the stent.

[0028] In this embodiment, the outer edge of the transmission wheel 8 is provided with an annular rack portion 9 along its circumference. The shrinking block 5 has a linear rack portion 10 on its side near the outer edge of the transmission wheel 8, which meshes with the annular rack portion 9. The transmission wheel 8 is driven to rotate by the meshing of the annular rack portion 9 and the linear rack portion 10 of the shrinking block 5. Specifically, the annular rack portion 9 is integrally machined on the outer edge of the transmission wheel 8, and each shrinking block 5 has an independent linear rack portion 10. The two are fully meshed. When the operating handle 3 drives the transmission wheel 8 to rotate, the annular rack synchronously drives the racks of all shrinking blocks 5. Through rack and pinion meshing, the circumferential rotation of the transmission wheel 8 is converted into the radial linear feed motion of each shrinking block 5. The rack meshing ensures that the feed displacement and feed speed of all shrinking blocks 5 are completely synchronized, with no difference in sequential action. This embodiment achieves circumferential synchronous meshing. The transmission mechanism ensures that the radial movement of the 6-8 contraction blocks 5 is completely consistent, applying uniform circumferential pressure to the stent and eliminating the problem of single-point stress concentration in traditional three-jaw tools. The rack and pinion meshing transmission has small clearance and high transmission precision, avoiding deformation and ensuring good vascular apposition after stent release during the operation. The rack and pinion transmission has stable load-bearing capacity, and the contraction process is smooth and without jamming, improving assembly efficiency. Furthermore, the rack and pinion meshing has a self-locking characteristic, and the contraction blocks 5 will not rebound after the handle is released, which can stably maintain the compression size and facilitate segmented multi-stage progressive contraction and segmented insertion of the sheath.

[0029] In this embodiment, the support frame 2 is provided with a plurality of limiting grooves 11 evenly arranged along its circumference. The limiting grooves 11 correspond one-to-one with the limiting blocks 7, and the limiting blocks 7 are slidably disposed within the limiting grooves 11. Specifically, the support frame 2 is provided with a number of limiting grooves 11 evenly arranged in a ring to match the number of limiting blocks 7. The limiting blocks 7 are embedded entirely within the grooves and can only slide along the length of the groove. The limiting grooves 11 constrain the movement trajectory of the limiting blocks 7, thereby achieving the minimum inner diameter limitation during contraction. The limiting grooves 11 guide and position the limiting blocks 7, ensuring that the contraction block 5 moves purely radially throughout its entire movement without deflection or skew, further improving the roundness of the support frame during compression.

[0030] In this embodiment, the limiting block 7 and the shrinking block 5 are detachably connected. The shrinking block 5 includes a transmission component 12 and a shrinking component 13. The transmission component 12 has a first insertion slot 14 extending through it. The top end of the shrinking component 13 has an insertion part 15 that engages with the first insertion slot 14. The transmission component 12 also has a second insertion slot 16 through which the limiting block 7 passes. The first insertion slot 14 and the second insertion slot 16 communicate with each other. The insertion part 15 also has a third insertion slot 17 through which the limiting block 7 passes. The second insertion slot 16 and the third insertion slot 17 are correspondingly arranged, and the limiting block 7 is inserted into the second insertion slot 16 and the third insertion slot 17. Specifically, the shrink block 5 is divided into a transmission component 12 (rack and pinion drive base) and a shrink component 13 (extrusion head that directly contacts the bracket); the transmission component 12 has first and second insertion slots 16, and the top of the shrink component 13 is provided with an insertion part 15, which has a third insertion slot 17; during assembly, the insertion part 15 is inserted into the first insertion slot 14 to complete radial positioning, and the limiting block 7 simultaneously passes through the second and third insertion slots 17 to achieve coaxial locking of the transmission component 12, the shrink component 13, and the limiting block 7; after receiving the rack driving force, the transmission component 12 transmits the thrust completely through the insertion structure. The front-end contraction component 13 compresses the vascular stent graft. Under the above configuration, the split structure separates the force transmission area from the workpiece contact area, and wear only occurs in the front-end contraction component 13. Simply replacing the contraction component 13 can restore the equipment's accuracy and extend the service life of the core transmission component 12. The multi-layer insertion slots and multiple limits prevent circumferential and radial movement between the transmission component 12 and the contraction component 13, ensuring uniform circumferential force during the compression process. The insertion assembly does not require complex fasteners, allowing for quick disassembly and assembly, and facilitating the rapid replacement of contraction components 13 with different arc-shaped contact surfaces during production to adapt to different wave-shaped stent grafts.

[0031] Specifically, in this embodiment, the limiting block 7 and the shrink block 5 are separate and detachable assembly structures, and the two are not rigidly bound together; the limiting block 7 and the shrink block 5 can be directly separated during disassembly, and directly aligned and combined during assembly; the limiting block 7 of different sizes can be replaced according to the diameter specifications of the bracket to be processed, and the shrinkage limit inner diameter can be adjusted to adapt to brackets of different sizes.

[0032] In this embodiment, the top end of the insertion part 15 is provided with a first connecting hole 18, and the limiting block 7 is provided with a second connecting hole 19. The first connecting hole 18 and the second connecting hole 19 are correspondingly arranged. Specifically, under the above arrangement, the top end of the insertion part 15 of the shrinking component 13 is provided with a first connecting hole 18, and the corresponding position of the limiting block 7 is provided with a second connecting hole 19. When the limiting block 7 passes through the second and third insertion slots 17 and is in place, the first connecting hole 18 and the second connecting hole 19 are completely coaxial, and a pin / screw can be inserted to complete the locking, rigidly fixing the limiting block 7, the shrinking component 13, and the transmission component 12 into a whole, so that they will not loosen or separate during the extrusion operation.

[0033] In this embodiment, the shrinkage component 13 is made of POM. Specifically, the shrinkage component 13, which is in direct contact with the PTFE membrane and nickel-titanium metal skeleton of the covered stent, is made of POM polymer material. POM material is flexible, has a smooth surface without sharp edges, and the five large arc-shaped contact surfaces of the shrinkage block fit the outer wall of the stent, so it will not scratch or cut the membrane during the compression process. The material does not precipitate or corrode, and will not contaminate the medical membrane. At the same time, it has moderate hardness, which can evenly transmit the extrusion force and will not cause local hard spots to damage the metal skeleton of the stent.

[0034] Example 2 In Embodiment 2 of this application, a contraction control method based on the aforementioned multi-stage progressive vascular stent graft radial contraction device includes the following steps: Step S1, Pre-installation and positioning: Place the nickel-titanium alloy + PTFE covered vascular stent into the hollow contraction channel, ensuring that the stent and the contraction channel are coaxial; Step S2, Single-turn progressive compression: Adjust the operating handle to drive the transmission wheel, causing all compression blocks to synchronously and slowly retract radially, uniformly applying pressure to the single-turn segment of the vascular stent to complete the initial compression, and then pushing the compressed stent segment into the matching compression sheath; specifically, the time for complete compression of a single-turn wave is controlled within 15-30 seconds; after compression, the stent roundness error is ≤0.028mm; the lining breakage rate is controlled within 0.05%; Step S3, Segmented Multi-Level Repetition: Adjust the opening of the operating handle and perform synchronous radial contraction on the residual wave loop of the vascular stent segment by segment. After each segment of compression is completed, push in the sheath. Step S4, Fine-tuning and calibration: After all the wave coils have shrunk, the operating handle 3 can be slightly adjusted to fine-tune the local shrinkage size to ensure the overall roundness of the support.

[0035] This application embodiment is applicable to the overall compression, partial single-segment compression, and local micro-adjustment of the size after compression of nickel-titanium alloy tubular covered stents, and is suitable for the pre-assembly process of interventional vascular stents of various materials and structures. This application embodiment can complete all contraction actions with only a single operating handle, without the need for multiple people to manually clamp and calibrate, reducing the skill threshold for operators, reducing size fluctuations caused by human operation errors, and significantly improving product consistency.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present invention without departing from the scope of the present invention are within the scope of the present invention.

Claims

1. A multi-stage progressive vascular stent graft radial shrinkage device, characterized in that: The device includes a base, a support frame mounted on the base, a wave-shaped shrinking mechanism movably mounted on the support frame, a control mechanism movably mounted on the support frame, and an operating handle movably mounted on the support frame. The wave-shaped shrinking mechanism has a ring-shaped structure and includes multiple shrinking blocks. The multiple shrinking blocks are evenly arranged circumferentially and enclose each other to form a hollow shrinking channel. The control mechanism includes a drive wheel and multiple limiting blocks. The limiting blocks are connected to the shrinking blocks one by one and are used to limit the minimum shrinking stroke of the shrinking blocks. The drive wheel is driven by the multiple shrinking blocks to synchronously drive all shrinking blocks to move radially. The drive wheel is rotatably mounted on the support frame. The operating handle is connected to the drive wheel. By driving the operating handle, the drive wheel is driven to rotate, synchronously driving the multiple shrinking blocks to close or open.

2. The multi-stage progressive vascular stent radial shrinkage device according to claim 1, characterized in that: The outer edge of the transmission wheel is provided with an annular rack portion along its circumference, and the shrink block is provided with a straight rack portion that meshes with the annular rack portion on the side near the outer edge of the transmission wheel. The transmission wheel is connected to the shrink block by meshing with the straight rack portion of the shrink block through the annular rack portion to drive the shrink block to rotate.

3. The multi-stage progressive vascular stent radial shrinkage device according to claim 1, characterized in that: The support frame is provided with a plurality of limiting grooves evenly arranged along its circumference. Each limiting groove corresponds to a limiting block, and the limiting block is slidably disposed in the limiting groove.

4. The multi-stage progressive vascular stent radial shrinkage device according to claim 1, characterized in that: The limiting block and the shrinking block are detachably connected.

5. The multi-stage progressive vascular stent radial shrinkage device according to claim 1, characterized in that: The shrink block includes a transmission component and a shrink component. The transmission component has a first insertion slot through it. The top end of the shrink component is provided with an insertion part that engages with the first insertion slot. The transmission component also has a second insertion slot through it for the limiting block to pass through. The first insertion slot and the second insertion slot are connected. The insertion part also has a third insertion slot through it for the limiting block to pass through. The second insertion slot and the third insertion slot are correspondingly provided. The limiting block is inserted into the second insertion slot and the third insertion slot.

6. The multi-stage progressive vascular stent radial shrinkage device according to claim 5, characterized in that: The top of the plug-in part is provided with a first connection hole, and the limiting block is provided with a second connection hole, with the first connection hole and the second connection hole being provided in correspondence.

7. The multi-stage progressive vascular stent radial shrinkage device according to claim 5, characterized in that: The material of the shrinking component is POM.

8. The multi-stage progressive vascular stent radial shrinkage device according to claim 1, characterized in that: The number of shrink blocks is 6 to 8.

9. The multi-stage progressive vascular stent radial shrinkage device according to claim 1, characterized in that: The number of limiting blocks is 6 to 8.

10. A contraction control method for a multi-stage progressive vascular stent graft radial contraction device according to any one of claims 1-9, characterized in that, Includes the following steps: Step S1, Pre-installation and positioning: Place the nickel-titanium alloy + PTFE covered vascular stent into the hollow contractile channel; Step S2, single-circle progressive contraction: Adjust the operating handle to drive the transmission wheel, which drives all the contraction blocks to synchronously and slowly contract radially, uniformly applying pressure to the single-circle segment of the vascular stent to complete the initial compression, and then push the compressed stent segment into the matching contraction sheath. Step S3, Segmented Multi-Level Repetition: Adjust the opening of the operating handle and perform synchronous radial contraction on the residual wave loop of the vascular stent segment by segment. After each segment of compression is completed, push in the sheath. Step S4, Fine-tuning and calibration: After all the wave loops have shrunk, adjust the operating handle to fine-tune the local shrinkage size so that the vascular stent as a whole maintains its roundness.

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