flow restriction device

Abstract

This invention provides a flow-limiting device, comprising a support, a fixed membrane, a movable membrane, and a side membrane. The fixed membrane surrounds the inner side of the support and is fixedly connected to the support. The movable membrane can axially approach or move away from the fixed membrane. The side membrane connects the fixed membrane and the movable membrane and has multiple connecting holes. The opening area of ​​the connecting holes can be adjusted according to the fluid flow, allowing the flow-limiting device to switch between a first state, a second state, and a third state. In the first, third, and second states, the distance between the movable membrane and the fixed membrane gradually decreases, and the opening area of ​​the connecting holes gradually decreases. When the flow-limiting device is in the third state, it can reduce rapid blood reflux, thus limiting blood flow and reducing the probability of tissue necrosis caused by excessively rapid blood reflux.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a flow limiting device. Background Technology

[0002] With the emergence of age-related diseases and other conditions, there is an increasing clinical need to reduce venous blood return. When human tissues are ischemic, reducing reflux helps maintain tissue saturation and ensures adequate nutrient supply, preventing excessively rapid reflux that could lead to tissue necrosis due to insufficient arterial blood supply. Conditions such as limb ischemic necrosis and myocardial ischemia require maintaining tissue saturation and reducing reflux. Therefore, a product capable of performing this function within blood vessels is needed to alleviate these conditions. Summary of the Invention

[0003] To address the aforementioned shortcomings, this invention provides a current limiting device.

[0004] This invention provides a current limiting device, the current limiting device comprising:

[0005] support;

[0006] A fixing membrane is provided, which surrounds the inner side of the bracket and is fixedly connected to the bracket;

[0007] A movable membrane, which may axially approach or move away from the fixed membrane;

[0008] A side membrane, which connects the fixed membrane and the movable membrane, is provided with a plurality of connecting holes;

[0009] The opening area of ​​the connecting hole can be adjusted according to the liquid flow, so that the flow limiting device can switch between a first state, a second state, and a third state. In the first state, the third state, and the second state, the distance between the movable membrane and the fixed membrane gradually decreases, and the opening area of ​​the connecting hole gradually decreases.

[0010] In the current limiting device of this invention embodiment, the active membrane is perpendicular to the axis of the current limiting device.

[0011] In the current limiting device of this invention embodiment, the active membrane is recessed toward the side closer to the side membrane.

[0012] In the current limiting device of this invention, the cross-sectional shape of the active membrane includes: arc, triangle, figure-eight, or trapezoid.

[0013] In the current limiting device of this invention, the active membrane and / or the side membrane are provided with support wires.

[0014] In the current limiting device of this embodiment, the fixed membrane has a through hole, and the current limiting device further includes:

[0015] Connectors;

[0016] A first filter screen is connected to the movable membrane via the connector, and the first filter screen and the movable membrane are spaced apart along the axial direction of the flow limiting device; in the first state, the first filter screen is in contact with the fixed membrane, and the first filter screen can cover the through hole; in the first state, the third state, and the second state, the distance between the first filter screen and the fixed membrane gradually increases.

[0017] The current limiting device in this embodiment of the invention further includes:

[0018] The scraper assembly includes an elastic arm and a scraper portion, wherein the scraper portion is connected to the bracket via the elastic arm and contacts the first filter screen;

[0019] During the process of the flow limiting device switching from the third state to the second state or the first state, the elastic arm can deform so that the scraping part can move relative to the first filter screen and maintain contact with the first filter screen, thereby enabling the scraping part to scrape the blood clot at the first filter screen.

[0020] In the flow limiting device of this embodiment, the scraper is located at the first end of the first filter screen on the side close to the fixed membrane; or, the scraper is located at the first end of the first filter screen on the side away from the fixed membrane.

[0021] In the flow limiting device of this invention embodiment, the scraper includes a plurality of scraper members, wherein a portion of the scraper members has a scraper portion disposed on the side of the first end of the first filter screen close to the fixed membrane, and another portion of the scraper members has a scraper portion disposed on the side of the first end of the first filter screen away from the fixed membrane.

[0022] The current limiting device in this embodiment of the invention further includes:

[0023] The second filter, connected to the support, is used to filter thrombi and can collect thrombi scraped off from the first filter by the scraper.

[0024] The flow limiting device provided in this embodiment of the invention allows the opening area of ​​the connecting hole to be adjusted according to the liquid flow, enabling the flow limiting device to switch between a first state, a second state, and a third state. In the first state, the third state, and the second state, the opening area of ​​the connecting hole gradually decreases. Therefore, in addition to the first and second states, the flow limiting device also has a third state different from the first and second states. In the third state, the opening area of ​​the connecting hole is smaller than that in the first state, and larger than that in the second state. When the flow limiting device is in the third state, it can reduce rapid blood reflux, thus limiting blood flow and ensuring that the blood in the tissue remains full, providing a certain nutrient supply and reducing the probability of tissue necrosis caused by excessively rapid blood reflux.

[0025] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the disclosure of the embodiments of the present invention. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a cross-sectional view of a current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a first state;

[0028] Figure 2 This is a schematic diagram of a flow-limiting device implanted into a blood vessel according to an embodiment of the present invention, wherein the flow-limiting device is in a first state;

[0029] Figure 3 This is an exploded view of a current limiting device provided in an embodiment of the present invention;

[0030] Figure 4 This is a cross-sectional view of a current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a second state;

[0031] Figure 5 This is a schematic diagram of a flow-limiting device implanted into a blood vessel according to an embodiment of the present invention, wherein the flow-limiting device is in a second state;

[0032] Figure 6 This is a cross-sectional view of a current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a third state;

[0033] Figure 7This is a schematic diagram of a flow-limiting device implanted into a blood vessel according to an embodiment of the present invention, wherein the flow-limiting device is in a third state;

[0034] Figure 8 This is a schematic diagram of the structure of a current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a third state;

[0035] Figure 9 This is a schematic diagram of the structure of the first filter screen provided in an embodiment of the present invention;

[0036] Figure 10 This is a partially exploded schematic diagram of a flow limiting device provided in an embodiment of the present invention, which shows a first filter screen and a second filter screen;

[0037] Figure 11 This is a schematic diagram of the structure of a current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a first state;

[0038] Figure 12 This is a schematic diagram of the structure of a current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a second state;

[0039] Figure 13 This is a schematic diagram of the structure of a current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a first state;

[0040] Figure 14 This is a schematic diagram of the structure of a current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a second state;

[0041] Figure 15 This is a schematic diagram of the structure of a current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a first state;

[0042] Figure 16 This is a schematic diagram of the structure of a current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a second state;

[0043] Figure 17 This is a schematic diagram of the current limiting device provided in an embodiment of the present invention, wherein the current limiting device is in a third state.

[0044] Explanation of reference numerals in the attached figures:

[0045] 100. Current limiting device;

[0046] 10. Stent; 11. Proximal end; 12. Distal end; 13. First sub-cavity; 14. Second sub-cavity; 15. First annular portion; 16. Second annular portion; 17. Third annular portion; 18. First connector; 19. Second connector; 10a. Stent body; 10b. Extension rod;

[0047] 20. Fixed membrane; 21. Through hole; 30. Movable membrane; 40. Side membrane; 41. Connecting hole; 50. Connector;

[0048] 60. First filter screen; 61. First end; 62. First side; 631. First cavity; 632. First opening; 64. First filter filament; 641. First filament segment; 642. Second filament segment;

[0049] 71. Limiting component; 72. Scraper bolt component; 721. Elastic arm; 722. Scraper bolt section;

[0050] 80. Second filter screen; 81. Second side; 811. First connecting section; 82. Second end; 821. Second connecting section; 822. Third connecting section; 823. Connection point; 824. Mesh opening; 83. Third side; 831. Fourth connecting section; 84. Filter chamber; 85. Second cavity; 86. Second opening;

[0051] 90. Support wire;

[0052] 200. Blood vessels. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0055] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0056] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0057] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0058] In the field of interventional medical devices, the "proximal end" is defined as the end closer to the heart, and the "distal end" is defined as the end farther from the heart. "Axial" refers to the direction parallel to the line connecting the center of the distal end and the center of the proximal end of the medical device, and "radial" refers to the direction perpendicular to the aforementioned axial direction.

[0059] This invention provides a flow-limiting device for restricting the flow of liquid passing through it. The liquid flowing through the flow-limiting device may include blood or other fluids within a biological body. The following explanation uses blood as an example, but the invention is not limited thereto.

[0060] Example 1

[0061] Please see Figures 1-7 In this embodiment of the invention, the flow limiting device 100 includes a support 10, a fixed membrane 20, a movable membrane 30, and a side membrane 40. The fixed membrane 20 surrounds the inner side of the support 10 and is fixedly connected to the support 10. The movable membrane 30 can axially approach or move away from the fixed membrane 20. The side membrane 40 connects the fixed membrane 20 and the movable membrane 30, and has a plurality of connecting holes 41. The opening area of ​​the connecting holes 41 can be adjusted according to the liquid flow, so that the flow limiting device 100 can switch between a first state, a second state, and a third state. In the first state, the third state, and the second state, the distance between the movable membrane 30 and the fixed membrane 20 gradually decreases, and the opening area of ​​the connecting holes 41 gradually decreases.

[0062] In the above embodiment, the flow limiting device 100 can switch between a first state, a second state, and a third state because the opening area of ​​the connecting hole 41 can be adjusted according to the liquid flow. In the first state, the third state, and the second state, the opening area of ​​the connecting hole 41 gradually decreases. Therefore, in addition to the first state and the second state, the flow limiting device 100 also has a third state that is different from the first state and the second state. In the third state, the opening area of ​​the connecting hole 41 is smaller than that in the first state, and the opening area of ​​the connecting hole 41 is larger than that in the second state. Therefore, when the flow limiting device 100 is in the third state, it can reduce the rapid blood reflux, so that the flow limiting device 100 can perform the function of blood flow limiting, so that the blood in the tissue can still be full of blood, play a certain role in nutrient supply, and reduce the probability of tissue necrosis caused by excessively rapid blood reflux and the arterial end not having enough time to supply blood. For example, it can reduce the probability of limb ischemic necrosis or myocardial ischemia.

[0063] Understandably, different opening areas of the connecting hole 41 result in different blood flow rates through the side membrane 40. The larger the opening area of ​​the connecting hole 41, the greater the blood flow rate through the side membrane 40, and the faster the blood return.

[0064] For example, when the current limiting device 100 is in the first state, such as Figure 1 and Figure 2 As shown. When the current limiting device 100 is in the second state, as... Figure 4 and Figure 5 As shown. When the current limiting device 100 is in the third state, as... Figure 6 and Figure 7 As shown.

[0065] Please see Figure 1 and Figure 2 For example, when the fluid pressure of the blood at the proximal end 11 of the stent 10 is greater than the fluid pressure at the distal end 12 of the stent 10, and the difference between the fluid pressure at the proximal end 11 and the fluid pressure at the distal end 12 is greater than a first preset threshold, the fluid flow on the side where the proximal end 11 is located will impact the movable membrane 30, causing the movable membrane 30 to move along the axial direction of the flow limiting device 100 from the proximal end 11 of the stent 10 toward the distal end 12 of the stent 10. The movable membrane 30 drives the side membrane 40 to move at the end close to the movable membrane 30, thereby increasing the opening area of ​​the connecting hole 41 until the flow limiting device 100 switches to the first state. When the flow limiting device 100 is in the first state, blood flows from the proximal end 11 of the stent 10 through the connecting hole 41 to the distal end 12 of the stent 10, so as to keep the distal end of the blood vessel 200 full of blood and realize tissue filling with blood.

[0066] Understandably, the term "proximal end 11" of stent 10 is merely a directional description, referring to the proximal side, but not a specific location. The proximal end face of stent 10 refers to the end face of the proximal end 11 of stent 10. Similarly, "distal end 12" of stent 10 is merely a directional description, referring to the proximal side, but not a specific location. The distal end face of stent 10 refers to the end face of the distal end 12 of stent 10.

[0067] Please see Figure 4 and Figure 5 For example, when the fluid pressure of the blood at the proximal end 11 of the stent 10 is less than the fluid pressure at the distal end 12 of the stent 10, and the difference between the fluid pressure at the distal end 12 and the fluid pressure at the proximal end 11 is greater than a second preset threshold, the fluid flow on the side where the distal end 12 is located will impact the movable membrane 30, causing the movable membrane 30 to move along the axial direction of the flow limiting device 100 from the distal end 12 of the stent 10 toward the proximal end 11 of the stent 10. This reduces the opening area of ​​the connecting hole 41 until the flow limiting device 100 switches to the second state. When the flow limiting device 100 is in the second state, the opening area of ​​the connecting hole 41 is small or even close to zero, the distance between the movable membrane 30 and the fixed membrane 20 is small, and it is difficult for the blood at the distal end 12 of the stent 10 to flow to the proximal end 11 of the stent 10. This effectively prevents rapid backflow of blood from the distal end of the blood vessel 200, which could cause tissue ischemia and achieve the function of preventing backflow.

[0068] Please see Figure 6 and Figure 7 For example, when the fluid pressure at the proximal end 11 of the stent 10 is not significantly different from the fluid pressure at the distal end 12 of the stent 10, or when the fluid pressure at the proximal end 11 of the stent 10 is slightly greater than the fluid pressure at the distal end 12 of the stent 10, the movable membrane 30 is slightly compressed, and the flow restrictor 100 is in its natural state, i.e., the third state. When the flow restrictor 100 is in the third state, blood can flow from the distal end 12 of the stent 10 through the connecting hole 41 to the proximal end 11 of the stent 10. In the third state, the opening area of ​​the connecting hole 41 is located between the opening area of ​​the connecting hole 41 in the first state and the opening area of ​​the connecting hole 41 in the second state; in the third state, the distance between the movable membrane 30 and the fixed membrane 20 is located between the distance between the movable membrane 30 and the fixed membrane 20 in the first state and the distance between the movable membrane 30 and the fixed membrane 20 in the second state. In the third state, the opening area of ​​the connecting hole 41 is moderate, and the blood of the distal end 12 of the stent 10 flows through the connecting hole 41 to the proximal end 11 of the stent 10. In this third state, there is a certain amount of return flow, which ensures that the blood returns to the proximal end of the blood vessel 200 for metabolic circulation.

[0069] Please see Figure 6 and Figure 8In some embodiments, the fixed membrane 20, the movable membrane 30, and the side membrane 40 divide the stent 10 into a first sub-cavity 13 and a second sub-cavity 14, with the first sub-cavity 13 being closer to the proximal end face of the stent 10 than the second sub-cavity 14. When the liquid pressure at the proximal end 11 of the stent 10 is greater than the liquid pressure at the distal end 12 of the stent 10, and the difference between the liquid pressure in the first sub-cavity 13 and the liquid pressure in the second sub-cavity 14 is greater than a first preset threshold, the movable membrane 10 can move axially along the flow-limiting device 100 under the action of the liquid flow on the side where the proximal end 11 is located, thereby increasing the opening area of ​​the connecting hole 41, and thus enabling the flow-limiting device 100 to switch from a second state or a third state to a first state, such as... Figure 1 and Figure 2 As shown. When the fluid pressure at the proximal end 11 of the stent 10 is less than the fluid pressure at the distal end 12 of the stent 10, and the difference between the fluid pressure in the second sub-cavity 14 and the fluid pressure in the first sub-cavity 13 is greater than a second preset threshold, the flow limiting device 100 can switch from the first state or the third state to the second state, as shown. Figure 4 and Figure 5 As shown. When the difference between the liquid pressure in the second sub-cavity 14 and the liquid pressure in the first sub-cavity 13 is less than or equal to a third preset threshold, the liquid pressure at the proximal end 11 of the stent 10 is not significantly different from the liquid pressure at the distal end 12 of the stent 10; or, the liquid pressure at the proximal end 11 of the stent 10 is slightly greater than the liquid pressure at the distal end 12 of the stent 10, and the flow limiting device 100 is in the third state, such as... Figures 6 to 8 As shown, blood in the second sub-cavity 14 can flow to the first sub-cavity 13, and the third preset threshold is less than the second preset threshold.

[0070] For example, the material of the scaffold 10 can be any suitable biocompatible material, such as PTFE or PET.

[0071] Please see Figure 3For example, the stent 10 includes a first annular portion 15, a second annular portion 16, a third annular portion 17, a plurality of first connectors 18, and a plurality of second connectors 19. The first annular portion 15, the second annular portion 16, and the third annular portion 17 are spaced apart along the axial direction of the flow limiting device 100. The two ends of the first connectors 18 are respectively connected to the first annular portion 15 and the second annular portion 16. The plurality of first connectors 18 are spaced apart along the circumferential direction of the flow limiting device 100. The plurality of second connectors 19 are spaced apart along the circumferential direction of the flow limiting device 100. The two ends of the second connectors 19 are respectively connected to the second annular portion 16 and the third annular portion 17. In this way, the stent 10 has good compliance performance and can better conform to the blood vessel 200, so that the stent 10 can fit tightly against the blood vessel 200, reducing the probability of displacement of the flow limiting device 100 within the blood vessel 200, and ensuring that the flow limiting device 100 can perform its blood flow limiting function. The fixing membrane 20 can be connected to at least one of the first connector 18, the second annular portion 16, and the second connector 19 by at least one of the following methods: sewing, adhesive bonding, or heat fusion. For example, the fixing membrane 20 can be connected to the second annular portion 16. The number of first connectors 18 and / or the number of second connectors 19 can be set to one or more. The number of first connectors 18 and the number of second connectors 19 can be the same or different. For example, the number of first connectors 18 and the number of second connectors 19 can be the same; one second connector 19 is provided along the length direction of one first connector 18, and the length direction of the first connector 18 is parallel to the axial direction of the flow limiting device 100.

[0072] At least two of the fixed membrane 20, the movable membrane 30, and the side membrane 40 are integrally formed, or at least two of the movable membrane 30, the side membrane 40, and the fixed membrane 20 are separately formed. For example, the movable membrane 30 and the side membrane 40 are integrally formed, and the side membrane 40 is connected to the fixed membrane 20 by at least one connection method such as sewing, adhesive bonding, etc. Alternatively, the movable membrane 30 is connected to the side membrane 40 by at least one connection method such as sewing, adhesive bonding, heat fusion, etc., and the side membrane 40 is connected to the fixed membrane 20 by at least one connection method such as sewing, adhesive bonding, heat fusion, etc.

[0073] The fixed membrane 20, the movable membrane 30, and the side membrane 40 may each be made of at least one of the following materials: polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), or other polymeric materials with good biocompatibility.

[0074] Please see Figure 8In some embodiments, the movable membrane 30 is perpendicular to the axial direction of the flow limiting device 100, thus simplifying the structure and processing of the movable membrane 30. For example, the surface of the movable membrane 30 is a plane, and this surface is perpendicular to the axial direction of the flow limiting device 100.

[0075] Please see Figure 3 and Figure 8 , combined Figure 1 , Figure 4 and Figure 6 In some embodiments, the fixed membrane 20 has a through hole 21. The flow limiting device 100 also includes a connector 50 and a first filter 60. The first filter 60 is connected to the movable membrane 30 via the connector 50, and the first filter 60 and the movable membrane 30 are spaced apart along the axial direction of the flow limiting device 100. In a first state, the first filter 60 is in contact with the fixed membrane 20, and the first filter 60 can cover the through hole 21. In the first state, the third state, and the second state, the distance between the first filter 60 and the fixed membrane 20 gradually increases. The first filter 60 is used to block thrombi or lumps and other particles in the blood, but it does not block the blood itself. Taking the first filter 60 as an example of blocking thrombi in the blood, the first filter 60 can filter thrombi in the blood, reducing the possibility of thrombi blocking the blood vessel 200. Specifically, since the first filter 60 is in contact with the fixed membrane 20 in the first state, the first filter 60 can cover the through hole 21. Therefore, the first filter 60 can filter thrombi in the reflux blood flowing from the distal end to the proximal end. The thrombi can adhere to the area of ​​the first filter 60 corresponding to the through hole 21 and adhere to the side of the first filter 60 near the distal end 12 of the stent 10, thereby enabling the first filter 60 to filter thrombi.

[0076] Please see Figure 1 and Figure 2 For example, when the flow limiting device 100 is in the first state, blood flows from the proximal end 11 of the stent 10 through the first filter screen 60 and then through the connecting hole 41 to the distal end 12 of the stent 10, so as to keep the distal end of the blood vessel 200 full of blood and realize tissue full of blood.

[0077] For example, one end of the connector 50 is connected to the first filter screen 60 by wire welding, and the other end of the connector 50 is connected to the movable membrane 30 by at least one of the following methods: sewing, adhesive bonding, heat fusion, etc.

[0078] The shape of the connector 50 can include a rod or any other suitable shape. For example, if the connector 50 is rod-shaped, it is easy to process, facilitating the fabrication of the flow-limiting device 100. The material of the connector 50 can be an alloy, such as a nickel-titanium alloy or a cobalt-chromium alloy. The extension direction of the connector 50 can pass through the center of the first filter screen 60 and / or the center of the movable membrane 30, so that the flow-limiting device 100 has better stability in the blood vessel 200. When subjected to the impact of blood flow or the torsion of the blood vessel 200, the flow-limiting device 100 is less likely to tilt, thereby giving the flow-limiting device 100 a more stable flow-limiting effect.

[0079] The material of the first filter screen 60 can be made of alloys or polymers with shape memory properties, such as nickel-titanium alloys, cobalt-chromium alloys, thermoplastic polyurethanes (TPU), polytetrafluoroethylene (PTFE), or polyethylene (PE). For example, the first filter screen 60 is made of a PTFE membrane.

[0080] Please see Figures 8 to 10 , combined Figure 1 Exemplarily, the first filter 60 includes a first end portion 61 and a first side portion 62. The first end portion 61 is connected to the connector 50. In a first state, the first end portion 61 contacts the fixing membrane 20 and can cover the through hole 21. The first side portion 62 is connected to the first end portion 61 and extends toward the side of the first end portion 61 away from the fixing membrane 20. The first side portion 62 and the first end portion 61 enclose a first cavity 631. Exemplarily, a first opening 632 is formed at the end of the first side portion 62 away from the first end portion 61, and the first opening 632 communicates with the first cavity 631.

[0081] Please see Figure 9In some embodiments, the first filter screen 60 may include one or more first filter filaments 64. Exemplarily, the first filter screen 60 is formed by interlacing and weaving a single first filter filament 64. Exemplarily, the first filter screen 60 includes multiple first filter filaments 64, which may be interlaced and woven together, or they may converge at the connector 50 without being connected. For example, the first filter filament 64 includes a first filter segment 641 and a second filter segment 642. The first filter segment 641 is connected to the connector 50, and the end of the first filter segment 641 away from the connector 50 is connected to the second filter segment 642. The first filter segments 641 of the multiple first filter filaments 64 are arranged circumferentially along the support 10 to form a first end portion 61, and the second filter segments 642 of the multiple first filter filaments 64 are arranged circumferentially along the support 10 to form a first side portion 62. There are no interconnecting points between the first filter wires 64, so as to simplify the processing of the first filter screen 60 while ensuring thrombus filtration, and to enable the first filter screen 60 to have better deformability, which is beneficial for the flow limiting device 100 to better conform to the blood vessel 200. For example, the distance between adjacent first filter sections 641 extends from the end closer to the connector 50 to the end farther away from the connector 50 in a gradually increasing direction, so that each first filter wire 64 can be bundled and connected to the connector 50.

[0082] For example, the first filter screen 60 is symmetrically arranged so that the flow limiting device 100 has better stability in the blood vessel 200. When subjected to the impact of blood flow or the torsion of the blood vessel 200, the flow limiting device 100 is not easy to tilt, thereby ensuring that the flow limiting device 100 has a more stable flow limiting effect.

[0083] Please see Figure 3 and Figure 8In some embodiments, the flow limiting device 100 further includes a limiting member 71 and a scraping member 72. The limiting member 71 is connected to the fixed membrane 20; the scraping member 72 includes an elastic arm 721 and a scraping portion 722. The elastic arm 721 is connected to the support 10, and the elastic arm 721 is connected to the scraping portion 722. During the process of the flow limiting device 100 switching from the third state to the second state or the first state, the elastic arm 721 can deform so that the scraping portion 722 can move relative to the first filter screen 60, and the scraping portion 722 can maintain contact with the first filter screen 60. This allows the scraping portion 722 to scrape the blood clot at the first filter screen 60, thereby dispersing the blood clot while ensuring that the first filter screen 60 has the function of filtering blood clots, preventing excessive accumulation of blood clots on the first filter screen 60 and forming a blockage, thus ensuring smooth blood flow. Because the elastic arm 721 has elastic potential energy, the scraping portion 722 adheres to the first filter screen 60. The limiting member 71 is used to restrict the movement of the scraping part 722 so that the scraping part 722 can be in a preset position to ensure that the scraping part 722 can effectively scrape the blood clot at the first filter screen 60.

[0084] In some embodiments, during the process of the flow limiting device 100 switching from the third state to the second state or the first state, the thrombus scraping part 722 can move from the middle of the first end 61 to the edge under the elastic force of the elastic arm 721 to scrape the thrombus on the first end 61 of the first filter screen 60.

[0085] For example, the scraping part 722 is provided on the side of the first end 61 of the first filter 60 near the fixing membrane 20, so that the scraping part 722 can scrape the blood clot on the side of the first end 61 near the fixing membrane 20.

[0086] For example, a first filter 60 is disposed in the first sub-cavity 13. When blood flowing from the distal end of the blood vessel toward the proximal end flows through the flow restrictor 100, the first filter 60 can filter out blood clots in the blood flowing through the first filter 60, and the blood clots in the blood flowing through the first filter 60 can adhere to the side of the first end 61 near the distal end 12 of the stent 10. A scraping portion 722 is disposed on the side of the distal end 12 of the stent 10, and the scraping portion 722 can scrape the blood clots on the side of the first end 61 near the distal end 12 of the stent 10.

[0087] For example, during the process of the flow limiting device 100 switching from the third state to the second state, blood flows from the distal end to the proximal end, and the scraping part 722 can move from the middle to the edge of the first end 61 under the elastic force of the elastic arm 721 to scrape the thrombus on the side of the first end 61 near the fixed membrane 20, or scrape the thrombus on the side of the first end 61 near the distal end 12 of the stent 10.

[0088] In some embodiments, the scraping portion 722 is provided on the side of the first end 61 of the first filter 60 away from the fixing membrane 20, so that the scraping portion 722 can scrape the blood clot on the side of the first end 61 away from the fixing membrane 20.

[0089] For example, a first filter 60 is disposed in the first sub-cavity 13. When blood flowing from the proximal end of the blood vessel toward the distal end flows through the flow restrictor 100, the first filter 60 can filter out blood clots in the blood flowing through the first filter 60, and the blood clots in the blood flowing through the first filter 60 can adhere to the side of the first end 61 near the proximal end 11 of the stent 10. A scraping portion 722 is disposed on the side of the first end 61 near the proximal end 11 of the stent 10, and the scraping portion 722 can scrape the blood clots on the side of the first end 61 near the proximal end 11 of the stent 10.

[0090] For example, during the process of the flow limiting device 100 switching from the third state to the first state, blood flows from the proximal end to the distal end. The scraping part 722 can move from the middle to the edge of the first end 61 under the elastic force of the elastic arm 721 to scrape the blood clot on the side of the distal end of the first filter 60 away from the fixed membrane 20, or scrape the blood clot on the side of the first end 61 near the proximal end 11 of the support 10.

[0091] In some embodiments, the thrombus scraping member 72 includes a plurality of scraping members, wherein a portion of the scraping member 72 has a scraping portion 722 disposed on the side of the first end 61 near the fixation membrane 20, and another portion of the scraping member 72 has a scraping portion 722 disposed on the side of the first end 61 away from the fixation membrane 20. In this way, it can scrape the thrombus on the side of the first end 61 near the fixation membrane 20, and also scrape the thrombus on the side of the first end 61 away from the fixation membrane 20.

[0092] The scraper 72 or the elastic arm 721 is welded to the bracket 10, and the scraper 72 or the scraper part 722 contacts the first filter screen 60. The shape of the scraper part 722 can be any suitable shape, such as: plate-shaped, strip-shaped, arc-shaped, etc.

[0093] The number of scraping elements 72 may include one or more. For example, the number of scraping elements 72 may include at least two, with each scraping element 72 spaced apart along the circumference of the support 10 on the first filter screen 60, so that the thrombus at the first filter screen 60 can be scraped off more efficiently and more completely.

[0094] Please see Figure 3 For example, the bracket 10 includes a bracket body 10a and an extension rod 10b, the bracket body 10a and the extension rod 10b are fixedly connected, and the elastic arm 721 is welded and fixed to the extension rod 10b.

[0095] Please see Figure 8 and Figure 10In some embodiments, the flow limiting device 100 further includes a second filter 80 connected to the stent 10. The second filter 80 is used to filter thrombi and can collect thrombi scraped off from the first filter 60 by the scraper 72. Exemplarily, the second filter 80 is at least used to block thrombi or lumps and other particles in the blood. Taking the blocking of thrombi in the blood as an example, the second filter 80 can filter thrombi in the blood, reducing the possibility of thrombi blocking the blood vessel 200. When blood flows from the distal end 12 of the stent 10 to the proximal end 11 of the stent 10, the first filter 60 can filter thrombi in the blood, or the first filter 60 and the second filter 80 can cooperate to filter thrombi in the blood. When blood flows from the proximal end 11 of the stent 10 to the distal end 12 of the stent 10, the first filter 60 and the second filter 80 can filter thrombi in the blood.

[0096] For example, in the first state, the first filter 60 can filter thrombi in the refluxed blood flowing from the distal end to the proximal end, and the thrombi can adhere to the side of the first end 61 near the distal end 12 of the stent 10. Furthermore, in the first state, the first filter 60 is in contact with the fixation membrane 20, and the first filter 60 can cover the through hole 21. The first filter 60, the second filter 80, and the fixation membrane 20 can cooperate to form a relatively closed cage structure, thus making it difficult for thrombi to detach from the cage structure. Thrombi within the cage structure are also less likely to flow with the blood to the distal tissue, reducing the risk of tissue necrosis due to thrombus accumulation.

[0097] The edge of the second filter 80 can be fixedly connected to the bracket 10 by at least one process such as adhesive bonding, laser welding, or sewing. The second filter 80 can filter large particles such as larger blood clots or lumps, as well as small particles such as small blood clots or lumps.

[0098] The material of the second filter 80 can be made of alloys or polymers with shape memory properties, such as nickel-titanium alloys, cobalt-chromium alloys, thermoplastic polyurethanes (TPU), polytetrafluoroethylene (PTFE), or polyethylene (PE). In this embodiment, the second filter 80 is made of a PTFE membrane.

[0099] Please see Figure 8 and Figure 10In some embodiments, the second filter 80 includes a second side 81, a second end 82, and a third side 83. The first side 62 is connected to the support 10. Both the second side 81 and the third side 83 are connected to the second end 82, and are spaced apart. The second side 81 is closer to the outer edge of the second end 82 than the third side 83. The second side 81, the second end 82, and the third side 83 cooperate to form a filter cavity 84, and the first filter 60 can cover the outside of the third side 83. The thrombus scraper 72 can scrape the thrombus on the first filter 60 into the filter cavity 84 formed by the second filter 80 for collection, thus achieving the thrombus collection function. The second side 81 can reduce the possibility of the thrombus in the filter cavity 84 detaching from the area corresponding to the second side 81. The second end 82 can filter thrombi in the blood. The third side 83 can reduce the possibility of the thrombus in the filter cavity 84 detaching from the area corresponding to the third side 83. For example, the second end 82 is closer to the proximal end face of the support 10 than the first end 61 of the first filter screen 60.

[0100] For example, the second filter screen 80 is woven from one or more braided filaments. See also Figure 10 For example, the second side portion 81 includes a plurality of first connecting segments 811, which are spaced apart circumferentially along the flow limiting device 100. The second end portion 82 includes a second connecting segment 821 and a third connecting segment 822, which are cross-connected to form connection points 823 and mesh openings 824. The second end portion 82 has a plurality of connection points 823 and a plurality of mesh openings 824 to ensure that the second end portion 82 can better filter thrombi. The third side portion 83 includes a plurality of fourth connecting segments 831, which are spaced apart circumferentially along the flow limiting device 100. The fourth connecting segments 831 are closer to the center of the second filter screen 80 than the first connecting segments 811. A second connecting segment 821 and a third connecting segment 822 are each connected to a first connecting segment 811, and a second connecting segment 821 and a third connecting segment 822 are each connected to a fourth connecting segment 831.

[0101] Please see Figure 10 For example, the second filter 80 has a second cavity 85 communicating with the first cavity 631, the first opening 632 communicating with the second cavity 85, and the third side portion 83 extending into the first cavity 631 of the first filter 60. Thus, the flow-limiting device 100 has a compact structure and good filtration effect on blood clots.

[0102] Please see Figure 8 and Figure 10For example, the second filter 80 cooperates with the first filter 60 to form a second opening 86, and the projection of the second opening 86 onto the plane of the fixed membrane 20 is located at the fixed membrane 20. In this way, it is possible to prevent the existence of a gap between the first filter 60 and the fixed membrane 20 in the first state, which would allow thrombi to easily leak to the distal end of the blood vessel 200.

[0103] For example, the second filter screen 80 is symmetrically arranged so that the flow limiting device 100 has better stability in the blood vessel 200 and is less likely to tilt when subjected to the impact of blood flow or the torsion of the blood vessel 200, thereby ensuring that the flow limiting device 100 has a more stable flow limiting effect.

[0104] Understandably, Figure 2 , Figure 5 and Figure 7 The dashed arrows in the diagram represent the path of blood flow, which are merely illustrative and not intended to be limiting.

[0105] Example 2

[0106] This embodiment of the invention provides a current limiting device 100, which is substantially the same as the current limiting device 100 provided in the first embodiment, except that the current limiting device 100 has an active membrane 30. Please refer to... Figure 11 and Figure 12 In some embodiments, the active membrane 30 is recessed towards the side closest to the side membrane 40. This allows blood flow to more easily converge at the recessed active membrane 30 when it impacts it, resulting in a more concentrated thrust. Consequently, the process of switching the flow limiting device 100 from the first or third state to the second state is more efficient. Exemplarily, in the second state, the active membrane 30, side membrane 40, and fixed membrane 20 can form a relative closure to reduce gaps caused by incomplete compression of the side membrane 40.

[0107] For example, the cross-sectional shape of the active membrane 30 includes: arc-shaped, triangular, figure-eight shaped, or trapezoidal, etc. See, for example, [link to relevant documentation]. Figure 11 and Figure 12 The cross-sectional shape of the active membrane 30 includes an arc shape. For example, please refer to... Figure 13 and Figure 14 The cross-sectional shape of the active membrane 30 includes an inverted V-shape or an inverted trapezoid. Understandably, Figure 11 or Figure 13 The current limiting device 100 is in the first state. Figure 12 or Figure 14 The current limiting device 100 is in the second state.

[0108] Example 3

[0109] This embodiment of the invention provides a current limiting device 100, which is substantially the same as the current limiting device 100 provided in the first embodiment, except that the current limiting device 100 has an active membrane 30. Please refer to... Figures 15 to 17 Support wires 90 are provided on the active membrane 30 and / or the side membrane 40 to support the active membrane 30 and / or the side membrane 40. For example, the active membrane 30 is provided with support wires 90. Another example is that the side membrane 40 is provided with support wires 90. Yet another example is that both the active membrane 30 and the side membrane 40 are provided with support wires 90. The material of the support wires 90 can be at least one of nickel-titanium alloy, cobalt-chromium alloy, or polymer materials. Understandably, Figure 15 The current limiting device 100 is in the first state. Figure 16 The current limiting device 100 is in the second state. Figure 17 The current limiting device 100 is in the third state.

[0110] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," "mechanical coupling," and "coupling" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and can refer to the internal communication of two components or the interaction between two components. Mechanical coupling or coupling of two components includes direct coupling and indirect coupling, such as a direct fixed connection or a connection through a transmission mechanism. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0111] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0112] The foregoing disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described above. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0113] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific method step, feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific method steps, features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0114] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A current limiting device, characterized by, The current limiting device includes: support; A fixing membrane is provided, which surrounds the inner side of the bracket and is fixedly connected to the bracket; A movable membrane, which may axially approach or move away from the fixed membrane; A side membrane, which connects the fixed membrane and the movable membrane, is provided with a plurality of connecting holes; The opening area of ​​the connecting hole can be adjusted according to the liquid flow, so that the flow limiting device can switch between a first state, a second state, and a third state. In the first state, the third state, and the second state, the distance between the movable membrane and the fixed membrane gradually decreases, and the opening area of ​​the connecting hole gradually decreases.

2. The current limiting device according to claim 1, characterized in that, The movable membrane is perpendicular to the axis of the flow limiting device.

3. The current limiting device according to claim 1, characterized in that, The active membrane is recessed toward the side closest to the side membrane.

4. The current limiting device according to claim 1, characterized in that, The cross-sectional shape of the active membrane includes: arc, triangle, figure-eight, or trapezoid.

5. The current limiting device according to claim 1, characterized in that, The active membrane and / or the side membrane are provided with support wires.

6. The current limiting device according to claim 1, characterized in that, The fixed membrane has a through hole, and the flow limiting device further includes: Connectors; A first filter screen is connected to the movable membrane via the connector, and the first filter screen and the movable membrane are spaced apart along the axial direction of the flow limiting device; in the first state, the first filter screen is in contact with the fixed membrane, and the first filter screen can cover the through hole; in the first state, the third state, and the second state, the distance between the first filter screen and the fixed membrane gradually increases.

7. The current limiting device according to claim 6, characterized in that, Also includes: The scraper assembly includes an elastic arm and a scraper portion, wherein the scraper portion is connected to the bracket via the elastic arm and contacts the first filter screen; During the process of the flow limiting device switching from the third state to the second state or the first state, the elastic arm can deform so that the scraping part can move relative to the first filter screen and maintain contact with the first filter screen, thereby enabling the scraping part to scrape the blood clot at the first filter screen.

8. The current limiting device according to claim 7, characterized in that, The scraper plug is located at the first end of the first filter screen on the side close to the fixing membrane; or, the scraper plug is located at the first end of the first filter screen on the side away from the fixing membrane.

9. The current limiting device according to claim 7, characterized in that, The scraper includes multiple scraper parts, some of which have scraper parts located at the first end of the first filter screen near the fixed membrane, while others have scraper parts located at the first end of the first filter screen away from the fixed membrane.

10. The current limiting device according to claim 7, characterized in that, Also includes: The second filter, connected to the support, is used to filter thrombi and can collect thrombi scraped off from the first filter by the scraper.

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