Vena cava filter conveying system and control method thereof

Abstract

The invention provides a vena cava filter conveying system and a control method thereof. The vena cava filter conveying system comprises a conveying sheath tube, a sealing assembly, a pushing assembly and a filter. The sealing assembly is arranged at the near end of the conveying sheath tube, the filter is contained in an inner cavity of the conveying sheath tube, and the pushing assembly continuously extends to the inner cavity of the sealing assembly and the inner cavity of the conveying sheath tube and drives the filter to move relative to the conveying sheath tube. The far end of the pushing assembly is provided with a limiting piece. The filter is provided with a plurality of groups of supporting structures which are distributed at equal intervals along the circumferential direction and have gradually increased lengths along the first direction; the supporting structure is propped between the conveying sheath tube and the radial direction of the limiting piece in a folded state, and the supporting structure in the folded state moves in the inner cavity of the conveying sheath tube in the first direction or the second direction opposite to the first direction through the pushing effect of the limiting piece. Through the application, the filter is accurately released at a proper position of the inferior vena cava, and the risk of thrombus shedding or filter displacement is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a vena cava filter delivery system and a control method thereof. Background Art

[0002] For patients with a high risk of pulmonary embolism, a filter can be implanted in the inferior vena cava to capture thrombi, which can effectively prevent thrombi from falling off and entering the lungs, thereby reducing the occurrence of pulmonary embolism. In the process of releasing the filter, if the position of the filter deviates from the position of the vena cava filter delivery device in the prior art, the position of the filter cannot usually be adjusted, which may cause the filter to fail to be accurately released at the appropriate position in the inferior vena cava, thereby increasing the risk of thrombus falling off or filter displacement, and reducing the success rate of the operation. Summary of the invention

[0003] The object of the present invention is to provide a vena cava filter delivery system and a control method thereof, especially to achieve accurate release of the filter at a suitable position in the inferior vena cava and reduce the risk of thrombus detachment or filter displacement.

[0004] According to the present invention, a vena cava filter delivery system is provided, comprising: a delivery sheath, a sealing component, a pushing component and a filter;

[0005] The sealing assembly is arranged at the proximal end of the delivery sheath, the filter is accommodated in the inner cavity of the delivery sheath, and the pushing assembly continuously extends to the sealing assembly and the inner cavity of the delivery sheath and drives the filter to move relative to the delivery sheath;

[0006] The distal end of the pushing component is provided with a limiting member;

[0007] The filter is constructed with a plurality of groups of support structures which are equally spaced along the circumference and whose lengths increase along the first direction;

[0008] The support structure is held in a folded state between the delivery sheath and the limiting member in a radial direction, and the folded support structure is moved in the inner cavity of the delivery sheath along the first direction or in a second direction opposite to the first direction by the pushing action of the limiting member.

[0009] According to the present invention, in some schemes, the filter includes: a head end, the head end is engaged with the tube opening of the delivery sheath, and a plurality of groups of the support structures are formed by extending the end of the head end along the first direction.

[0010] According to the present invention, in some solutions, the support structure includes: a plurality of first support arms, second support arms, and third support arms, the lengths of which increase along a first direction;

[0011] The length of the first support arm is smaller than the length of the second support arm, and the length of the second support arm is smaller than the length of the third support arm.

[0012] According to the present invention, in some schemes, the exterior of the head end is a conical structure and forms a through guidewire cavity, the center of the head end is hollowed out to form a hook-shaped structure, and the head end is constructed with a protrusion that fits into the tube opening of the delivery sheath.

[0013] According to the present invention, in some solutions, the limiting member at least partially radially abuts against the third support arm in the retracted state, and extends toward the first support arm.

[0014] According to the present invention, in some schemes, the pushing assembly includes: an inner sheath tube, which continuously extends to the inner cavity of the sealing assembly and the delivery sheath tube, the limit member is sleeved on the outer side of the distal end of the inner sheath tube, and a handle is configured on one end of the inner sheath tube extending out of the sealing assembly.

[0015] According to the present invention, in some embodiments, the first support arm includes: a first support portion and a second support portion extending continuously outward relative to the axis of the filter, and a third support portion connecting the second support portion and extending continuously inward relative to the axis of the filter.

[0016] According to the present invention, in some embodiments, the overall contour of the second support arm is an arc-shaped structure, and the free end of the second support arm is configured with a barb that is bent radially outward for anchoring on the inner wall of the blood vessel.

[0017] According to the present invention, in some embodiments, the overall profile of the third support arm is a linear structure, and the free end of the third support arm extends along the first direction to form an anchor barb for anchoring on the inner wall of the blood vessel.

[0018] According to the present invention, in some aspects, the angle at which the first support portion of the first support arm extends outward from the distal end of the head end is greater than the angle at which the second support arm extends outward from the distal end of the head end.

[0019] According to the present invention, in some solutions, the sealing assembly includes: a multi-channel valve tube and a suction tube, a side tube connected to the suction tube is constructed on the side of the multi-channel valve tube, and a sealing member is arranged at the proximal end of the multi-channel valve tube;

[0020] The inner sheath tube passes through the multi-channel valve tube along the second direction and extends to the delivery sheath tube, and the sealing member is used for sealing the connection between the inner sheath tube and the proximal end of the multi-channel valve tube.

[0021] The present invention also provides a control method for a vena cava filter delivery system, which is applied to the above-mentioned vena cava filter delivery system and comprises the following steps:

[0022] S1. Exhaust the air inside the delivery sheath through the sealing assembly;

[0023] S2, guide the delivery sheath along the guide wire into the target position of the inferior vena cava;

[0024] S3, the pushing component drives the limiting member to move along the second direction, and the supporting structure in the collapsed state is moved along the second direction in the inner cavity of the delivery sheath toward the outside of the inner cavity of the delivery sheath through the pushing action of the limiting member;

[0025] S4. After the filter moves from the inner cavity of the delivery sheath to the target position outside the inner cavity of the delivery sheath, the support structure switches from the collapsed state to the expanded state.

[0026] According to the present invention, in some schemes, the pushing assembly drives the limiting member to move along the second direction, and the supporting structure in the collapsed state is moved along the second direction in the inner cavity of the delivery sheath toward the outside of the inner cavity of the delivery sheath through the pushing action of the limiting member, including:

[0027] If the release position of the filter is offset, before a group of support structures near the distal end of the delivery sheath are deployed, the push assembly drives the support structures to move in the inner cavity of the delivery sheath along a first direction to adjust the release position of the filter;

[0028] After the filter is adjusted to a suitable release position, the pushing assembly drives the support structure to move in the inner cavity of the delivery sheath along the second direction to the outside of the inner cavity of the delivery sheath to the target position.

[0029] The vena cava filter delivery system and control method thereof according to the present invention have the following beneficial technical effects: during the process of the filter gradually moving toward the target position, if the release position of the filter is offset, before a group of support structures near the distal end of the delivery sheath completely detach from the inner cavity of the delivery sheath, the pushing assembly is controlled to drive the limiting member to move along the first direction. Since the support structure that has not completely detached from the inner cavity of the delivery sheath is still in a retracted state, the pushing assembly can drive the supporting structure to move in the inner cavity of the delivery sheath along the guide wire direction through the pushing action of the limiting member to adjust the release position of the filter. After the filter is adjusted to a suitable release position, the pushing assembly is controlled to drive the supporting structure to move toward the target position in the inner cavity of the delivery sheath through the pushing action of the limiting member to achieve accurate release of the filter at the target position, thereby reducing the risk of thrombus detachment or filter displacement, ensuring the stability of the filter in the correct position in the blood vessel, and giving full play to its function of capturing thrombus. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1It is an overall schematic diagram of the vena cava filter delivery system disclosed by the present invention;

[0031] Figure 2 Schematic diagram of the vena cava filter delivery system omitting the delivery sheath and aspiration tube;

[0032] Figure 3 is a schematic diagram of a plurality of groups of support structures whose lengths increase along a first direction;

[0033] Figure 4 is a cross-sectional view of the filter being accommodated in the delivery sheath in a collapsed state;

[0034] Figure 5 is a schematic diagram of the expanded state of the filter;

[0035] Figure 6 A flow chart of a control method for a vena cava filter delivery system. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the technical solution of the present disclosure clearer, the technical solution of the embodiment of the present disclosure will be clearly and completely described in combination with the drawings of the specific embodiments of the present disclosure. The same figure marks in the drawings represent the same parts. It should be noted that the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0037] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the invention belongs. The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Inside", "outside", "up", "down", "far", "near", "front", "back" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0038] The drawings in this disclosure are not drawn strictly according to the actual scale, and the specific size and quantity of each structure can be determined according to actual needs. The drawings described in this disclosure are only schematic diagrams of the structures.

[0039] It should be noted that the “axis” refers to Figure 1The direction indicated by the axis Q of the delivery sheath 10. The "radial direction" refers to the direction J passing through the axis Q.

[0040] Pulmonary embolism (PE) and deep vein thrombosis (DVT) are collectively referred to as venous thrombosis (VTE). The Vena Cava Filter (VCF) is a filtering device designed to prevent pulmonary embolism caused by emboli detaching from the superior and inferior vena cava systems.

[0041] Vena cava filters can be mainly divided into the following categories according to their duration of use and functions: Temporary filters. Temporary filters are usually used for patients who need to prevent blood clots from falling off in the short term. Permanent filters. Permanent filters are designed to be implanted for a long time and cannot be removed. They are suitable for patients with lifelong high risks. Retrievable filters. Retrievable filters combine the advantages of temporary filters and permanent filters. They can be implanted when needed and removed through surgery or other medical means after the risk of thrombosis decreases. Patients can benefit when the risk of thrombosis is high, and avoid the side effects of long-term implantation when the risk is reduced.

[0042] However, during the process of releasing the filter, if the position of the filter deviates, the position of the filter cannot usually be adjusted, which may result in the filter not being accurately released at the appropriate position in the inferior vena cava, thereby increasing the risk of thrombus detachment or filter displacement and reducing the success rate of the operation.

[0043] The vena cava filter delivery system 100 disclosed in the present application is relative to the vena cava filter delivery device in the prior art. When the release position of the filter 40 is offset, before a group of support structures 42 near the distal end of the delivery sheath 10 are unfolded, the vena cava filter delivery system 100 drives the support structure 42 to move along a first direction in the inner cavity of the delivery sheath 10 through a pushing assembly 30 to adjust the release position of the filter 40. After the filter 40 is adjusted to a suitable release position, the pushing assembly 30 drives the support structure 42 to move along a second direction in the inner cavity of the delivery sheath 10 toward the outside of the inner cavity of the delivery sheath 10 to the target position, so as to achieve the precise release of the filter 40 at a suitable position in the inferior vena cava and reduce the risk of thrombus detachment or displacement of the filter 40.

[0044] Please refer to Figures 1 to 5 A specific embodiment of a vena cava filter delivery system 100 is disclosed.

[0045] The vena cava filter delivery system 100 comprises: a delivery sheath 10, a sealing assembly 20, a pushing assembly 30 and a filter 40; the sealing assembly 20 is arranged at the proximal end of the delivery sheath 10, the filter 40 is accommodated in the inner cavity of the delivery sheath 10, the pushing assembly 30 continuously extends to the inner cavities of the sealing assembly 20 and the delivery sheath 10 and drives the filter 40 to move relative to the delivery sheath 10; a limiting member 31 is arranged at the distal end of the pushing assembly 30; the filter 40 is constructed to have a plurality of groups of equally spaced filters distributed along the circumference and having a length along a first direction (such as Figure 3 The support structure 42 is held between the delivery sheath 10 and the radial direction J of the stopper 31 in a collapsed state, and the support structure 42 in the collapsed state is pushed by the stopper 31 in a first direction or in a second direction opposite to the first direction (i.e., Figure 4 The spherical conveyor moves in the inner cavity of the delivery sheath tube 10 (in the direction indicated by the middle arrow X2).

[0046] The vena cava filter delivery system 100 provided in the above embodiment of the present application, during the operation, a guide wire (not shown) is introduced into the target blood vessel, and a guide path is provided for the delivery filter 40 through the guide wire. After the air inside the delivery sheath 10 is evacuated through the sealing component 20, the delivery sheath 10 is introduced into the target position of the inferior vena cava along the guide wire. At the same time, the filter 40 is kept in a retracted state in the inner cavity of the delivery sheath 10. After reaching the target position, the pushing component 30 is controlled to drive the limiting member 31 to move along the second direction, so as to drive the support structure 42 (such as the support structure 42) in the retracted state through the pushing action of the limiting member 31. Figure 4 The support structure 42 shown in FIG. 1 ) moves in the inner cavity of the delivery sheath 10 toward the outside of the inner cavity of the delivery sheath 10 along the second direction. By continuously pushing the stopper 31 along the second direction, the filter 40 will gradually move to the target position. The plurality of support structures 42 (i.e., Figure 5 The support structures 42a, 42b and 42c shown in the figure are separated from the inner cavity of the delivery sheath tube 10 in sequence along the second direction. The support structure 42 completely separated from the inner cavity of the delivery sheath tube 10 can be switched from the retracted state to the expanded state (such as Figure 5 The support structure 42 shown in FIG.

[0047] During the process of the filter 40 gradually moving toward the target position, if the release position of the filter 40 is offset, a group of support structures 42 (i.e., Figure 5Before the support structure 42a shown in the figure is completely separated from the inner cavity of the delivery sheath 10, the pushing assembly 30 is controlled to drive the limit member 31 to move along the first direction. Since the support structure 42a that has not completely separated from the inner cavity of the delivery sheath 10 is still in a retracted state, the pushing assembly 30 can drive the support structure 42 to move in the inner cavity of the delivery sheath 10 along the first direction through the pushing action of the limit member 31 to adjust the release position of the filter 40. After the filter 40 is adjusted to a suitable release position, the pushing assembly 30 is controlled to drive the support structure 42 to move toward the target position in the inner cavity of the delivery sheath 10 through the pushing action of the limit member 31, so as to achieve the precise release of the filter 40 at the target position, thereby reducing the risk of thrombus detachment or displacement of the filter 40, ensuring the stability of the correct position of the filter 40 in the blood vessel, and giving full play to its function of capturing thrombus.

[0048] In some examples, the air inside the delivery sheath 10 is evacuated through the sealing component 20 so that there is no air in the delivery sheath 10, thereby preventing air from entering the blood vessel during the delivery process to reduce surgical risks.

[0049] In some examples, the stopper 31 and the delivery sheath 10 form a radial J abutment on the support structure 42, so that the outer surface of the stopper 31 contacts the inner surface of the support structure 42, and the outer surface of the support structure 42 contacts the inner surface of the delivery sheath 10, thereby forming a friction force to limit the position of the filter 40 in the inner cavity of the delivery sheath 10, and prevent the filter 40 from being separated from the inner cavity of the delivery sheath 10 before reaching the target position, thereby avoiding erroneous release. And through the friction force between the stopper 31 and the support structure 42, the stopper 31 can push the support structure 42 during the movement in the first direction or the second direction, so as to drive the support structure 42 to move synchronously.

[0050] In some examples, during the process of the filter 40 moving from the inner cavity of the delivery sheath 10 to the target position, the multiple groups of support structures 42 are separated from the inner cavity of the delivery sheath 10 in sequence, and are switched from the folded state to the expanded state in sequence after being completely separated from the inner cavity of the delivery sheath 10. The multiple groups of support structures 42 of the filter 40 are deployed in sequence, rather than all at once, thereby reducing the impact force of all-at-once deployment on the blood vessels, and by deploying in sequence to evenly distribute the pressure applied to the blood vessels, damage to the blood vessels is avoided. And in the process of the multiple groups of support structures 42 being deployed in sequence, a group of support structures 42 that is preferentially completely separated from the inner cavity of the delivery sheath 10, after being deployed, provides stable support for the support structures 42 that are subsequently separated from the inner cavity of the delivery sheath 10 by abutting against the blood vessel wall, thereby ensuring that the filter 40 can be smoothly and accurately deployed and released at the target position.

[0051] In some examples, the material of the stopper 31 is a flexible material, such as silicone, polyurethane (PU), thermoplastic elastomer (TPE), etc., which is not limited in the present disclosure. So that the stopper 31 can flexibly fix the support structure 42 of the filter 40 and provide support force and elastic buffering. In the process of conveying the support structure 42, the stopper 31 and the support structure 42 form a moderate friction force, which can stabilize the retracted state of the support structure 42, and can drive the support structure 42 to slide smoothly in the inner cavity of the conveying sheath 10 when the push component 30 applies force.

[0052] In some examples, reference Figures 1 to 4 As shown, the filter 40 includes: a head end 41, which is engaged with the tube mouth of the delivery sheath 10, and a plurality of support structures 42 are formed by extending the end of the head end 41 along the first direction. The head end 41 is engaged with the tube mouth of the delivery sheath 10 to keep the filter 40 stable in the inner cavity of the delivery sheath 10 during the delivery process, and further prevent the filter 40 from being separated from the inner cavity of the delivery sheath 10 before reaching the target position, thereby avoiding erroneous release. In the process of the pushing component 30 driving the limit member 31 to move along the second direction, the support structure 42 in the folded state is driven by the pushing action of the limit member 31 to move in the inner cavity of the delivery sheath 10 along the second direction, so that the head end 41 engaged with the tube mouth of the delivery sheath 10 is detached from the inner cavity of the delivery sheath 10. In the process of the filter 40 gradually moving to the target position, the multiple groups of support structures 42 are detached from the inner cavity of the delivery sheath 10 in turn, and are switched from the folded state to the expanded state in turn, so that after the filter 40 is released at the target position, the multiple groups of support structures 42 are expanded and form a stable umbrella-shaped structure to maintain the stability of the filter 40 in the blood vessel and effectively capture and prevent blood clots from entering the lungs.

[0053] In some examples, reference Figures 3 to 5As shown, the support structure 42 includes: a plurality of first support arms 421, a second support arm 422, and a third support arm 423, the lengths of which increase along a first direction; the length of the first support arm 421 is less than the length of the second support arm 422, and the length of the second support arm 422 is less than the length of the third support arm 423. The lengths of the first support arm 421, the second support arm 422, and the third support arm 423 gradually increase, so that each group of support arms (i.e., the first support arms 421, the second support arms 422, and the third support arms 423, the lengths of which increase along the first direction) can gradually apply a supporting force to the inner wall of the blood vessel when they are deployed in sequence, so that the filter 40 can be stably deployed and maintained in position in the inferior vena cava. Furthermore, by gradually increasing the length of the first support arm 421, the second support arm 422, and the third support arm 423, the filter 40 can adapt to different blood vessel diameters. The first support arm 421 with a shorter length is close to the proximal end of the filter 40 to adapt to the blood vessel diameters and morphologies of different patients, while the second support arm 422 and the third support arm 423 with a longer diameter are located at the distal end of the filter 40 to adapt to larger blood vessel diameters, so that the filter 40 can provide stable support when deployed to prevent the filter 40 from shifting or becoming unstable in the blood vessel. By gradually deploying the first support arm 421, the second support arm 422, and the third support arm 423, the fixing ability of the filter 40 is enhanced to ensure that the filter 40 can be stably maintained at the target position for a long time.

[0054] In some examples, reference Figure 4 and Figure 5 As shown, the outside of the head end 41 is a conical structure and is formed with a through guidewire cavity (not shown), the center of the head end 41 is hollowed out to form a hook-shaped structure, and the head end 41 is constructed with a protrusion 411 that fits the tube mouth of the delivery sheath 10. The conical structure outside the head end 41 helps to smoothly guide the filter 40 through the blood vessel during the delivery process to reduce the resistance of the delivery sheath 10 during the introduction process. The guidewire cavity provides an introduction channel for the guidewire, so that the guidewire can pass through the head end 41 and guide the filter 40 to accurately move to the target position to ensure the precise positioning of the filter 40. The hook-shaped structure is used to recover the filter 40. The protrusion 411 allows the head end 41 to fit with the tube mouth of the delivery sheath 10 to prevent the filter 40 from accidentally loosening during the delivery process, and ensure that the filter 40 is stably kept in a retracted state in the inner cavity of the delivery sheath 10.

[0055] In some examples, reference Figure 4 and Figure 5As shown, the stopper 31 at least partially radially abuts the third support arm 423 in the retracted state, and extends toward the first support arm 421. The stopper 31 ensures the stability of the filter 40 during the delivery process by abutting the third support arm 423 in the retracted state in the radial direction. The third support arm 423 is fixed in the inner cavity of the delivery sheath 10 by the abutting effect of the stopper 31 to prevent it from accidentally unfolding or deflecting during the delivery process, ensuring that the filter 40 can smoothly pass through the blood vessel and reach the target position, and can push the third support arm 423 to drive the filter 40 to move in the inner cavity of the delivery sheath 10 along the second direction or the first direction through the friction between the stopper 31 and the third support arm 423. In some examples, the stopper 31 can extend to the second support arm 422 along the second direction, or even to the first support arm 421, so that the stopper 31 radially abuts the first support arm 421, the second support arm 422 and the third support arm 423 in the retracted state. Thus, the gradual release of the first support arm 421 , the second support arm 422 and the third support arm 423 can be effectively controlled to ensure that the filter 40 is unfolded smoothly and accurately.

[0056] In some examples, reference Figures 2 to 4 As shown, the push assembly 30 includes: an inner sheath tube 32, the inner sheath tube 32 continuously extends to the inner cavity of the sealing assembly 20 and the conveying sheath tube 10, a stopper 31 is sleeved on the outer side of the distal end of the inner sheath tube 32, and a handle 33 is configured on the inner sheath tube 32 extending from one end of the sealing assembly 20. The inner sheath tube 32 continuously extends into the inner cavity of the sealing assembly 20 and the conveying sheath tube 10, and the inner cavity of the inner sheath tube 32 is aligned and communicated with the guide wire cavity in the head end 41 to provide an introduction channel for the guide wire. The movement of the inner sheath tube 32 and the stopper 31 in the inner cavity of the conveying sheath tube 10 is controlled by the handle 33 to adjust the position of the filter 40 in real time, and the inner sheath tube 32 can guide the filter 40, so that the filter 40 remains stable during the conveying process, and the filter 40 can be accurately and smoothly deployed to the target position in the inferior vena cava.

[0057] In some examples, reference Figures 2 to 4 As shown, the inner sheath tube 32 is radially inwardly recessed to form a connecting tube section 321 configured with the stopper 31, and the distal end of the connecting tube section 321 is connected to the head end 41. The outer diameter of the connecting tube section 321 is smaller than the outer diameter of the inner sheath tube 32, so that the inner cavity of the delivery sheath tube 10 can accommodate the stopper 31 and the support structure 42 in the collapsed state through the connecting tube section 321, so as to reduce the friction and resistance during the release process of the filter 40, and ensure that the filter 40 can be released smoothly and gradually deployed.

[0058] In some examples, reference Figure 5As shown, the first support arm 421 includes: a first support portion 4211 and a second support portion 4212 extending continuously outward relative to the axis of the filter 40 , and a third support portion 4213 connecting the second support portion 4212 and extending continuously inward relative to the axis of the filter 40 .

[0059] The first support part 4211 supports the initial deployment of the first support arm 421 to provide initial external force support during the deployment of the first support arm 421, and the second support part 4212 is deployed to provide greater support force to the first support arm 421. The first support part 4211 and the second support part 4212 jointly support the deployment of the first support arm 421, and the second support part 4212 can distribute the support force during the deployment process, so that the first support arm 421 applies uniform pressure to the blood vessel during the deployment process, ensuring that the filter 40 will not cause excessive local pressure on the blood vessel when it is deployed in the target, thereby avoiding blood vessel damage. The third support part 4213 extends inward to form a centripetal support force inside the filter 40, thereby balancing the outward support forces of the first support part 4211 and the second support part 4212, so as to prevent the first support arm 421 from being deformed due to excessive outward support during deployment, and ensure the overall rigidity and stability of the filter 40.

[0060] In some examples, reference Figure 5 As shown, the overall profile of the second support arm 422 is an arc-shaped structure, and the free end of the second support arm 422 is provided with a barb 4221 that is bent radially outward for anchoring on the inner wall of the blood vessel. The overall profile of the second support arm 422 is an arc-shaped structure. When the second support arm 422 is deployed, its arc-shaped structure is easy to adapt to the shape of the blood vessel, so that the part of the second support arm 422 that contacts the blood vessel wall can evenly distribute pressure on the blood vessel wall, avoid causing excessive local pressure on the blood vessel, and reduce the risk of blood vessel damage. And the second support arm 422 can provide uniform support for the filter 40 when the filter 40 is deployed, ensure stable deployment at the target position of the filter 40, and provide stable support for the subsequent release of the third support arm 423. After the filter 40 is deployed, the barb 4221 is firmly in contact with the inner wall of the blood vessel to prevent the filter 40 from moving with the blood flow in the blood vessel, so that the filter 40 can be stably maintained at the target position.

[0061] In some examples, reference Figure 5As shown, the overall profile of the third support arm 423 is a linear structure, and the free end of the third support arm 423 extends along the first direction to form an anchor thorn 4231 for anchoring on the inner wall of the blood vessel. The linear structure of the third support arm 423 helps to provide a more stable linear support for the filter 40 in the blood vessel, so that the filter 40 can provide a solid support force when it is deployed. In addition, the third support arm 423 can be deployed quickly and stably to prevent the filter 40 from being subjected to excessive disturbance, so that the filter 40 is kept in the target position, and the stability of the filter 40 structure is ensured. The anchor thorn 4231 has the function of piercing the blood vessel wall, ensuring that the filter 40 can be firmly anchored on the inner wall of the blood vessel, and preventing the filter 40 from shifting or falling off under the action of blood flow.

[0062] In some examples, reference Figure 5 As shown, the angle at which the first support portion 4211 of the first support arm 421 extends outward from the end of the head end 41 is greater than the angle at which the second support arm 422 extends outward from the end of the head end 41. The first support portion 4211 of the first support arm 421 extends outward from the head end 41 at a greater angle to provide a stronger initial support force during the deployment of the filter 40, so that the filter 40 can quickly adapt to the space in the blood vessel and ensure that the filter 40 can provide sufficient support in the initial stage of deployment so that the filter 40 can be stably positioned at the target position in the blood vessel.

[0063] In some examples, reference Figure 1 As shown, the sealing assembly 20 includes: a multi-channel valve tube 21 and a suction tube 22, a side tube 211 connected to the suction tube 22 is constructed on the side of the multi-channel valve tube 21, and a sealing member (not shown) is arranged at the proximal end of the multi-channel valve tube 21; the inner sheath tube 32 penetrates the multi-channel valve tube 21 along the second direction and extends to the delivery sheath tube 10, and the sealing member is used to seal the connection between the inner sheath tube 32 and the proximal end of the multi-channel valve tube 21. A vacuum device (not shown) is connected to the outside of the suction tube 22, so that the suction tube 22 can suck and empty the air in the multi-channel valve tube 21 and the delivery sheath tube 10, clean the air or impurities inside the vena cava filter delivery system 100, and ensure the smooth delivery of the filter 40. The sealing member is arranged at the proximal end of the multi-channel valve tube 21, and is used to seal the connection between the inner sheath tube 32 and the multi-channel valve tube 21 to prevent the leakage of blood, liquid or gas, maintain the sealing performance of the sealing assembly 20, and prevent the risks caused by the leakage of gas or blood. In some examples, the seal may be configured as a sealing nut to lock the position of the inner sheath 32 and maintain the sealing of the sealing assembly 20. During the process of delivering the filter 40 through the inner sheath 32, the sealing nut may be loosened appropriately so that the inner sheath 32 can move relative to the delivery sheath 10 to adjust the release position of the filter 40.

[0064] Based on the same inventive concept, this embodiment also discloses a control method of a vena cava filter delivery system 100. Figure 6As shown, the vena cava filter delivery system 100 disclosed above is used to assist surgery, including the following steps:

[0065] S1. The internal air of the delivery sheath 10 is exhausted through the sealing component 20; S2. The delivery sheath 10 is introduced into the target position of the inferior vena cava along the guide wire; S3. The pushing component 30 drives the limiting member 31 to move along the second direction, i.e., the guide wire direction, and the supporting structure 42 in the folded state is moved along the second direction in the inner cavity of the delivery sheath 10 toward the outside of the inner cavity of the delivery sheath 10 through the pushing action of the limiting member 31; S4. After the filter 40 moves from the inner cavity of the delivery sheath 10 to the target position outside the inner cavity of the delivery sheath 10, the supporting structure 42 switches from the folded state to the expanded state.

[0066] Specifically, during the operation, a guide wire (not shown) is introduced into the target blood vessel, and a guide path is provided for the delivery filter 40 through the guide wire, and the second direction is the guide wire direction. After the air inside the delivery sheath 10 is evacuated through the sealing component 20, the delivery sheath 10 is introduced into the target position of the inferior vena cava along the guide wire, and is directly introduced and released along the guide wire. At the same time, the filter 40 is kept in a retracted state in the inner cavity of the delivery sheath 10. After reaching the target position, the pushing component 30 is controlled to drive the limiter 31 to move along the second direction, so as to drive the support structure 42 (such as the support structure 42) in the retracted state through the pushing action of the limiter 31. Figure 4 The support structure 42 shown in FIG. 1 ) moves in the inner cavity of the delivery sheath 10 toward the outside of the inner cavity of the delivery sheath 10 along the second direction. By continuously pushing the stopper 31 along the second direction, the filter 40 will gradually move to the target position. The plurality of support structures 42 (i.e., Figure 5 The support structures 42a, 42b and 42c shown in the figure are separated from the inner cavity of the delivery sheath 10 in sequence along the second direction, and the support structure 42 completely separated from the inner cavity of the delivery sheath 10 can be switched from the folded state to the expanded state.

[0067] In some examples, if the release position of the filter 40 is offset, before a group of support structures 42 near the distal end of the delivery sheath 10 are unfolded, the pushing assembly 30 drives the support structure 42 to move along a first direction in the inner cavity of the delivery sheath 10 to adjust the release position of the filter 40; after the filter 40 is adjusted to a suitable release position, the pushing assembly 30 drives the support structure 42 to move along a second direction in the inner cavity of the delivery sheath 10 toward the outside of the inner cavity of the delivery sheath 10 to the target position, thereby reducing the risk of thrombus detachment or displacement of the filter 40, ensuring the stability of the filter 40 in the correct position in the blood vessel, and giving full play to its function of capturing thrombus.

[0068] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A vena cava filter delivery system, characterized in that: include: Delivery sheath, sealing assembly, push assembly and filter; The sealing assembly is arranged at the proximal end of the delivery sheath, the filter is accommodated in the inner cavity of the delivery sheath, and the pushing assembly continuously extends to the sealing assembly and the inner cavity of the delivery sheath and drives the filter to move relative to the delivery sheath; The distal end of the pushing component is provided with a limiting member; The filter is constructed with a plurality of groups of support structures which are equally spaced along the circumference and whose lengths increase along the first direction; The support structure is held in a folded state between the delivery sheath and the limiting member in a radial direction, and the folded support structure is moved in the inner cavity of the delivery sheath along the first direction or in a second direction opposite to the first direction by the pushing action of the limiting member.

2. The vena cava filter delivery system according to claim 1, characterized in that: The filter comprises: a head end, the head end is engaged with the tube opening of the delivery sheath tube, and a plurality of groups of the support structures are formed by extending the end of the head end along the first direction.

3. The vena cava filter delivery system according to claim 2, characterized in that: The support structure comprises: a plurality of first support arms, a second support arm and a third support arm with lengths increasing along a first direction; The length of the first support arm is smaller than the length of the second support arm, and the length of the second support arm is smaller than the length of the third support arm.

4. The vena cava filter delivery system according to claim 2, characterized in that: The outside of the head end is a cone-shaped structure and is formed with a through guidewire cavity. The center of the head end is hollowed out to form a hook-shaped structure. The head end is constructed with a protruding portion that fits into the tube opening of the delivery sheath.

5. The vena cava filter delivery system according to claim 3, characterized in that: The limiting member at least partially radially abuts against the third supporting arm in the retracted state, and extends toward the first supporting arm.

6. The vena cava filter delivery system according to claim 1, characterized in that: The pushing assembly includes: an inner sheath tube, which continuously extends to the inner cavity of the sealing assembly and the conveying sheath tube, the limiting member is sleeved on the outer side of the distal end of the inner sheath tube, and a handle is arranged on one end of the inner sheath tube extending out of the sealing assembly.

7. The vena cava filter delivery system according to claim 3, characterized in that: The first support arm includes a first support portion and a second support portion which continuously extend outward relative to the axis of the filter, and a third support portion which connects the second support portion and continuously extends inward relative to the axis of the filter.

8. The vena cava filter delivery system according to claim 3, characterized in that: The overall profile of the second support arm is an arc-shaped structure, and the free end of the second support arm is provided with a barb that is bent radially outward for anchoring on the inner wall of the blood vessel.

9. The vena cava filter delivery system according to claim 3, characterized in that: The overall profile of the third support arm is a linear structure, and the free end of the third support arm extends along the first direction to form an anchor barb for anchoring on the inner wall of the blood vessel.

10. The vena cava filter delivery system according to any one of claims 7 to 8, characterized in that: The angle at which the first support portion of the first support arm extends outward from the distal end of the head end is greater than the angle at which the second support arm extends outward from the distal end of the head end.

11. The vena cava filter delivery system according to claim 6, characterized in that: The sealing assembly comprises: a multi-channel valve tube and a suction tube, a side tube connected to the suction tube is constructed on the side of the multi-channel valve tube, and a sealing member is arranged at the proximal end of the multi-channel valve tube; The inner sheath tube passes through the multi-channel valve tube along the second direction and extends to the delivery sheath tube, and the sealing member is used for sealing the connection between the inner sheath tube and the proximal end of the multi-channel valve tube.

12. A control method for a vena cava filter delivery system according to any one of claims 1 to 11, characterized in that: The steps include: S1. Exhaust the air inside the delivery sheath through the sealing assembly; S2, guide the delivery sheath along the guide wire into the target position of the inferior vena cava; S3, the pushing component drives the limiting member to move along the second direction, and the supporting structure in the collapsed state is moved along the second direction in the inner cavity of the delivery sheath toward the outside of the inner cavity of the delivery sheath through the pushing action of the limiting member; S4. After the filter moves from the inner cavity of the delivery sheath to the target position outside the inner cavity of the delivery sheath, the support structure switches from the collapsed state to the expanded state.

13. The control method of the vena cava filter delivery system according to claim 12, characterized in that: The pushing assembly drives the limiting member to move along the second direction, and the supporting structure in the collapsed state is moved along the second direction from the inner cavity of the delivery sheath to the outside of the inner cavity of the delivery sheath through the pushing action of the limiting member, including: If the release position of the filter is offset, before a group of support structures near the distal end of the delivery sheath are deployed, the push assembly drives the support structures to move in the inner cavity of the delivery sheath along a first direction to adjust the release position of the filter; After the filter is adjusted to a suitable release position, the pushing assembly drives the support structure to move in the inner cavity of the delivery sheath along the second direction to the outside of the inner cavity of the delivery sheath to the target position.

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