CN109771089B

CN109771089B - Filter device

Info

Publication number: CN109771089B
Application number: CN201811574831.4A
Authority: CN
Inventors: 贾小乐
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2018-12-21
Filing date: 2018-12-21
Publication date: 2021-11-16
Anticipated expiration: 2038-12-21
Also published as: CN109771089A

Abstract

The invention discloses a filter, which comprises a connecting rod assembly, and a first filter screen and a second filter screen which are arranged at intervals along the axial direction of the connecting rod assembly, wherein the connecting rod assembly comprises a first connecting rod and a second connecting rod which are connected in a separable mode, the first filter screen is fixed on the first connecting rod and extends in a radiation mode towards a direction far away from the first connecting rod, and the second filter screen is fixed on the second connecting rod and extends in a radiation mode towards a direction far away from the second connecting rod. The invention has the beneficial effects that: in summary, the filter embodying the present invention has the following beneficial effects: because the first connecting rod of this application is connected with the second connecting rod is separable, then can be with first filter screen and the split of second filter screen into two independent filter screen units, can retrieve first filter screen and second filter screen respectively in the time quantum of difference.

Description

Filter device

Technical Field

The invention relates to the technical field of interventional medical instruments, in particular to a filter.

Background

This section provides background information related to the present disclosure only and is not necessarily prior art.

Pulmonary Embolism (PE) is a common disease, has high fatality rate, and can be caused by various emboli falling off in the systemic circulation. The vena cava filter (hereinafter referred to as filter) is clinically proved to be a safe and effective means for preventing pulmonary embolism, and the filter is placed in the inferior vena cava to filter thrombus falling off from the inferior vena cava, so that the fallen thrombus is prevented from reaching the lung along the blood flow, and the incidence rate of the pulmonary embolism is reduced.

After the filter has been implanted for a period of time, although it intercepts a significant amount of thrombus, it still has a significant amount of free thrombus in the inferior vena cava, at which point the filter that intercepted a significant amount of thrombus is removed and a new filter is implanted, which would otherwise cause occlusion of the inferior vena cava. This way of re-implanting a new filter increases the economic burden on the patient due to the higher selling price of the filter.

Disclosure of Invention

The object of the present invention is to solve at least one of the problems of the prior art mentioned above, and the object is achieved by the following technical solutions:

the invention provides a filter, which comprises a connecting rod assembly, and a first filter screen and a second filter screen which are arranged at intervals along the axial direction of the connecting rod assembly, wherein the connecting rod assembly comprises a first connecting rod and a second connecting rod which are connected in a separable mode, the first filter screen is fixed on the first connecting rod and extends in a radiation mode in a direction far away from the first connecting rod, and the second filter screen is fixed on the second connecting rod and extends in a radiation mode in a direction far away from the second connecting rod.

In the filter of the present invention, a locking mechanism is disposed between the first link and the second link, and when the locking mechanism is unlocked, the first link and the second link can slide relatively.

In the strainer of the present invention, the strainer further includes two recovery hooks respectively provided on the first link and the second link.

In the filter according to the invention, the first sieve comprises a plurality of struts for supporting against the inner wall of the blood vessel, and the second sieve comprises first struts which are detachably connected to the struts.

In the filter of the present invention, the support rods are fixed to the first connecting rod and extend radially away from the first connecting rod.

In the filter of the present invention, the first filter screen further includes a plurality of connecting rods, one end of each connecting rod is fixed to the first connecting rod, and the other end of each connecting rod is connected to the support rod.

In the filter of the present invention, the number of the first struts is plural, the plural first struts are distributed around the circumference of the connecting rod assembly, and the first struts are fixed to the second connecting rod and extend radially away from the second connecting rod, respectively.

In the filter of the present invention, the second filter screen further includes a second strut, one end of the second strut is fixed to the second connecting rod, and the other end of the second strut extends radially away from the second connecting rod and is used for supporting the inner wall of the blood vessel.

In the filter of the invention, one end of the support rod is bent and extended towards one side of the longitudinal central axis of the filter to form a lower bent section.

In the filter, the distance between two ends of the lower folding section is 5-20 mm, and the included angle between the connecting line of the two ends of the lower folding section and the longitudinal central axis of the filter is 20-60 degrees.

In summary, the filter embodying the present invention has the following beneficial effects: because the first connecting rod of this application is connected with the second connecting rod is separable, then can be with first filter screen and the split of second filter screen into two independent filter screen units, can retrieve first filter screen and second filter screen respectively in the time quantum of difference.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a schematic view of a strainer according to a first embodiment of the present invention in a compressed state;

FIG. 2 is a schematic view of the filter of FIG. 1 returned to a predetermined configuration;

FIG. 3 is a schematic view of the strainer of FIG. 2 with the first and second rods separated;

FIG. 4 is a schematic view of a first configuration of a locking mechanism of the colander of FIG. 2;

FIG. 5 is a schematic view of a second configuration of the locking mechanism of the colander of FIG. 2;

FIG. 6 is a schematic view of a filter according to a second embodiment of the present invention returned to a predetermined configuration;

FIG. 7 is a schematic view of the filter of FIG. 6 with the support rods separated from the first branches;

FIG. 8 is a schematic view of a first detachable connection of the support rod to the first branch of the colander of FIG. 6;

FIG. 9 is a schematic view of a second detachable connection of the support rod to the first leg of the colander of FIG. 6;

FIG. 10 is a schematic view of the attachment rods of the first screen of the strainer of FIG. 6 being Y-shaped rods;

FIG. 11 is a schematic view of a second screen of the strainer of FIG. 6 including second struts;

fig. 12 is a schematic view of the filter according to the third embodiment of the present invention, in which the support rods are connected to the first support rod.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the field of interventional medicine, it is generally defined that an implant (e.g., a filter) is proximal at the end proximal to the heart and distal at the end distal to the heart after release.

The first embodiment:

referring to fig. 1 and 2, a first embodiment of the present invention provides a filter 100 that may be made of a superelastic shape memory alloy material, such as nitinol, such that the filter 100 may be contained within a delivery sheath in a compressed state and may automatically return to a predetermined configuration after release from the delivery sheath. Fig. 1 is a schematic view of filter 100 in a compressed state, and fig. 2 is a schematic view of filter 100 of the first embodiment when it returns to a predetermined configuration.

Referring to fig. 2 and 3, the strainer 100 includes a connecting rod assembly 3, and two first strainers 1 and two second strainers 2 arranged at intervals along an axial direction of the connecting rod assembly 3. The connecting rod assembly 3 comprises a first connecting rod 31 and a second connecting rod 32 which are connected in a separable manner, the first filter screen 1 is fixed on the first connecting rod 31 and extends radially in a direction away from the first connecting rod 31, and the second filter screen 2 is fixed on the second connecting rod 32 and extends radially in a direction away from the second connecting rod 32.

When the filter 100 is recovered, the first link 31 and the second link 32 can be moved relative to each other by an external force until the first link 31 and the second link 32 are separated from each other. Because first connecting rod 31 and second connecting rod 32 separable connection, then can be with first filter screen 1 and the split of second filter screen 2 become two independent filter screen units, can retrieve first filter screen 1 and second filter screen 2 respectively in the time quantum of difference. For example, when the filter 100 is implanted for a period of time, if the first filter 1 intercepts a large amount of thrombus and the amount of thrombus on the second filter 2 is not large, the first filter 1 loaded with thrombus may be taken out first, and after the second filter 2 intercepts a large amount of thrombus, the second filter 2 may be taken out without implanting a new filter, thereby reducing the economic burden of the patient.

Referring to fig. 2 and 3, the first filter screen 1 includes a plurality of support rods 11 for abutting against the inner wall of the blood vessel, and a plurality of connecting rods 12 located between the support rods 11 and the first connecting rods 31, wherein the plurality of connecting rods 12 are arranged at intervals around the circumference of the first connecting rods 31. One end of the connecting rod 12 is fixed on the first connecting rod 31, the other end of the connecting rod 12 extends towards the direction far away from the first connecting rod 31 and the direction radiation near the second filter screen 2, the supporting rod 11 is connected at the other end of the connecting rod 12, and the connecting rod 12 can assist the supporting rod 11 to make the supporting rod 11 tightly fit with the inner wall of the blood vessel. In this embodiment, the number of the support rods 11 is the same as that of the connecting rods 12, each connecting rod 12 is correspondingly connected to one support rod 11, the plurality of support rods 11 are circumferentially spaced around the first connecting rod 31, the support rods 11 and the connecting rods 12 are straight rods, and the support rods 11 are substantially parallel to the axial direction of the first connecting rod 31.

It should be understood that the present embodiment is not limited to the specific structure of the supporting rod 11 or the supporting rod 11, and in other embodiments, the supporting rod 11 or the supporting rod 11 may also be a curved rod or a combination of a curved rod and a straight rod. For example, when the support rod 11 is a curved rod, the support rod 11 extends toward the side away from the second filter screen 2 and gradually turns reversely to be curled, so that the support rod 11 is supported on the inner wall of the blood vessel. It should also be understood that the present embodiment does not limit the specific structure of the first filter screen 1, for example, in other embodiments, the first filter screen 1 may only include a plurality of support rods 11, where one end of each support rod 11 is fixed on the first connecting rod 31, and the other end of each support rod 11 extends radially away from the first connecting rod 31 and is used for abutting against the inner wall of the blood vessel. It will also be appreciated that the present embodiment does not limit the extending direction of the first screen 1, and the first screen 1 may extend towards a side away from or close to the second screen 2.

The second filter screen 2 comprises a plurality of first struts 21 distributed around the circumference of the second connecting rod 32, one ends of the first struts 21 are connected to the second connecting rod 32, and the other ends of the first struts 21 extend radially in a direction away from the second connecting rod 32 and are used for abutting against the inner wall of the blood vessel. In the present embodiment, the first strut 21 extends toward the side away from the first screen 1, but the present embodiment does not limit the structure of the first strut 21, and in other embodiments, the first strut 21 may also extend toward the side close to the first screen 1, or the first strut 21 may be turned upside down after extending toward the side close to the first screen 1.

Further, filter 100 includes a retraction hook 4 coupled to first and

second rods

31 and 32, respectively, wherein retraction hook 4 is selectively disposed at either the proximal end or the distal end of first rod 31 or second rod 32. In this embodiment, the recovery hook 4 on the first link 31 is located at an end of the first link 31 away from the second screen 2, and the recovery hook 4 on the second link 32 is located at an end of the second link 32 close to the first screen 1. Filter 100 further includes a fixation anchor 5 disposed on support rod 11, which fixation anchor 5 penetrates the inner wall of the blood vessel when filter 100 is implanted, which acts to fix filter 100.

In order to increase the safety factor of clinical use and avoid the random relative movement of the first link 31 and the second link 32 under the impact of blood flow or the radial pressure of the inner wall of the blood vessel after the filter 100 is implanted into the blood vessel, a locking mechanism 33 is disposed between the first link 31 and the second link 32. When the locking mechanism 33 is in the locked state, the first link 31 and the second link 32 are not movable relative to each other; when the locking mechanism 33 is unlocked, the first link 31 and the second link 32 can slide relatively.

In the embodiment shown in fig. 4, a sliding groove 311 is provided in the first link 31 and penetrates in the axial direction, and one end of the second link 32 is slidably coupled in the sliding groove 311. The locking mechanism 33 includes a plurality of limiting grooves 331 axially disposed on an inner wall of the sliding groove 311, and a limiting member 332 disposed on an end portion or an outer wall of the second link 32, the plurality of limiting grooves 331 extending to an end portion of the sliding groove 311. Under the action of external force, the limiting member 332 can slide from one limiting groove 331 to the other limiting groove 331 until the second link 32 is separated from the first link 31. In particular, the limiting member 332 is made of a flexible material, which is elastically deformable by a force. The side wall surface of the stopper groove 331 away from the recovery hook 4 is an inclined surface, and the side wall surface of the stopper groove 331 close to the recovery hook 4 is a substantially vertical surface. The side wall surface of the stopper 332 that is away from the recovery hook 4 is also an inclined surface, the inclined surface of the stopper 332 is substantially the same as the inclined surface of the stopper groove 331 in inclination angle, and the side wall surface of the stopper 332 that is close to the recovery hook 4 is also substantially a vertical surface. Because the side wall surfaces of the limiting groove 331 and the limiting member 332 far away from the recovery hook 4 are inclined surfaces, the two inclined surfaces can be matched to play a driving role, and the limiting member 332 can conveniently slide into the other limiting groove 331 from one limiting groove 331. In addition, since the side wall surfaces of the limit groove 331 and the limit member 332 close to the recovery hook 4 are both vertical surfaces, the two vertical surfaces can be engaged to play a role in stopping, so that the limit member 332 cannot move toward one side of the recovery hook 4. Therefore, the locking mechanism 33 of the present embodiment can ensure that the first link 31 and the second link 32 can move relatively only under the action of a large external force, and the first link 31 can move only in one direction, thereby ensuring the stability of the filter 100 in the blood vessel.

In the present embodiment, the specific structure of the locking mechanism 33 is not limited, and the first link 31 and the second link 32 may be prevented from moving relative to each other. For example, in the embodiment shown in fig. 5, a sliding groove 311 is provided in the first link 31 so as to penetrate in the axial direction, and one end of the second link 32 is slidably connected to the sliding groove 311. The locking mechanism 33 includes a fixing groove 333 provided on an outer wall of the first link 31 in communication with the sliding groove 311, and a fixing member 334 protrudingly provided on an outer wall of the second link 32, the fixing member 334 being slidably coupled in the fixing groove 333, the fixing groove 333 extending to an end of the first link 31 so that the fixing member 334 can be disengaged from the fixing groove 333. Specifically, the fixing groove 333 includes a fixing section 3331, a connecting section 3332, and a sliding section 3333, which are sequentially connected. The sliding section 3333 extends to an end of the first link 31 in the axial direction, and one end of the connection section 3332 is connected to an end of the sliding section 3333 near the recovery hook 4 and extends in the circumferential direction of the first link 31. The fixing section 3331 is connected to the other end of the connecting section 3332 and extends toward a side away from the recovery hook 4 in the axial direction of the first link 31. When the colander is in the predetermined configuration, the fixture 334 is positioned within the fixed section 3331. When the strainer is recovered, the fixing member 334 is moved from the fixing section 3331 into the connecting section 3332 by an external force, and then the fixing member 334 is moved from the connecting section 3332 into the sliding section 3333 by rotating the second link 32.

Referring to fig. 6 and 7, a second embodiment of the present invention provides a strainer, which is substantially the same as the strainer of the first embodiment, the strainer 100 includes a connecting rod assembly 3, and a first strainer 1 and a second strainer 2 respectively fixed to the connecting rod assembly 3, the connecting rod assembly 3 includes a first connecting rod 31 and a second connecting rod 32 connected in a separable manner, the first strainer 1 is fixed to the first connecting rod 31 and extends radially away from the first connecting rod 31, and the second strainer 2 is fixed to the second connecting rod 32 and extends radially away from the second connecting rod 32.

The second embodiment differs from the first embodiment in that the first screen 1 comprises a plurality of struts 11 for supporting on the inner wall of a blood vessel, the second screen 2 comprises first struts 21, and the first struts 21 are detachably connected to the struts 11. Fig. 6 is a schematic view showing the filter 100 of the second embodiment returned to the predetermined form after being released from the delivery sheath, in which the support rod 11 is connected to the first support rod 21, so that the filter 100 has a closed frame structure in the predetermined form.

When the filter 100 is in use, the filter 100 is in a predetermined shape, the support rod 11 is connected with the first support rod 21, and the support rod 11 can be tightly attached to the inner wall of the blood vessel under the auxiliary support of the first support rod 21, so that the stability of the whole filter is improved, and the filter 100 is prevented from inclining and shifting under the influence of factors such as blood flow. When the filter 100 needs to be recovered, the connection between the support rod 11 and the first support rod 21 is released, and after the support rod 11 is separated from the first support rod 21, the support rod 11 and the first support rod 21 can be easily pulled out like a nail embedded in the inner wall of a blood vessel. Therefore, the first support rod 21 and the support rod 11 are detachably connected, so that the filter 100 has good stability in use, is convenient to recover, prolongs the recovery time window of the filter, and effectively meets clinical requirements.

Referring to fig. 8, the supporting rod 11 is provided with a sliding slot 110 extending to an end of the supporting member 11, and the end of the first supporting rod 21 is provided with a sliding member 210, and the sliding member 210 is slidably connected in the sliding slot 110. When the colander is in the predetermined configuration, the slide 210 is positioned within the chute 110. When the filter is recovered, the slider 210 moves in the chute 110 until the slider 210 is separated from the end of the support rod 11, releasing the connection between the support rod 11 and the first support rod 21.

In the present embodiment, the connection between the support lever 11 and the first lever 21 is released by relatively moving the first link 31 and the second link 32, but the present invention is not limited to a specific manner of releasing the connection between the support lever 11 and the first lever 21. For example, in the embodiment shown in fig. 9, the support rod 11 and the first support rod 21 are connected by the degradable connecting element 6, and the degradation period of the degradable connecting element 6 is about the same as the time window of the filter 100 implanted in the body, that is, when the filter 100 reaches the time of extraction, the degradable connecting element 6 has been completely degraded or the mechanical properties of the material thereof have been lost, so that the constraint between the support rod 11 and the first support rod 21 is released. When the restraint between the support bar 11 and the first link 21 is released, the first link 31 and the second link 32 are relatively moved, and the first link 31 and the second link 32 are separated.

Referring to fig. 6 and 7 again, the first filter screen 1 further includes a plurality of connecting rods 12 located between the supporting rods 11 and the first connecting rods 31, and the plurality of connecting rods 12 are spaced around the circumference of the first connecting rods 31. One end of the connecting rod 12 is fixed on the first connecting rod 31, the other end of the connecting rod 12 extends towards the direction far away from the first connecting rod 31 and the direction radiation near the second filter screen 2, the supporting rod 11 is connected at the other end of the connecting rod 12, and the connecting rod 12 can assist the supporting rod 11 to make the supporting rod 11 tightly fit with the inner wall of the blood vessel. In this embodiment, the number of the support rods 11 is the same as that of the connecting rods 12, each connecting rod 12 is correspondingly connected to one support rod 11, the plurality of support rods 11 are circumferentially spaced around the first connecting rod 31, the support rods 11 and the connecting rods 12 are straight rods, and the support rods 11 are substantially parallel to the axial direction of the first connecting rod 31.

It should be understood that the present embodiment is not limited to the specific structure of the first filter screen 1, and in other embodiments, the first filter screen 1 may only include a plurality of support rods 11, where one end of each support rod 11 is fixed on the first connecting rod 31, and the other end of each support rod 11 extends radially away from the first connecting rod 31 and is used for abutting against the inner wall of the blood vessel. Alternatively, in other embodiments, the connecting rod 12 is a supporting rod of other shapes, for example, in the embodiment shown in fig. 10, the connecting rod 12 is a Y-shaped rod including a main branch section 12a and two branch sections 12b branched from one end of the main branch section 12a, the other end of the main branch section 12a is connected to the first connecting rod 31, and each branch section 12b is connected to one supporting rod 11. Alternatively, in other embodiments, the first filter 1 further includes other rod-like or net-like structures between the support rods 11 and the first connecting rods 31, as long as the other rod-like or net-like structures do not contact with the inner wall of the blood vessel, so as to ensure that only the support rods 11 of the first filter 1 contact with the inner wall of the blood vessel, and at this time, the first filter 1 can be easily pulled out like nails embedded in the inner wall of the blood vessel.

It should also be understood that the present embodiment is not limited to the specific structure of the supporting rod 11 or the supporting rod 11, and in other embodiments, the supporting rod 11 or the supporting rod 11 may also be a curved rod or a combination of a curved rod and a straight rod. For example, when the support rod 11 is a curved rod, the support rod 11 extends toward the side away from the second filter screen 2 and gradually turns reversely to be curled, so that the support rod 11 is supported on the inner wall of the blood vessel. It will also be appreciated that the present embodiment does not limit the extending direction of the first screen 1, and the first screen 1 may extend towards a side away from or close to the second screen 2.

Referring to fig. 6 and 7 again, the second filter screen 2 includes a plurality of first struts 21 distributed around the circumference of the second connecting rod 32, one end of the first struts 21 is connected to the second connecting rod 32, and the other end of the first struts 21 extends radially away from the second connecting rod 32 and is detachably connected to the support rod 11. In the present embodiment, the first strut 21 extends toward the side away from the first screen 1, but the present embodiment does not limit the structure of the first strut 21, and in other embodiments, the first strut 21 may also extend toward the side close to the first screen 1, or the first strut 21 may be turned upside down after extending toward the side close to the first screen 1.

It should be understood that the plurality of first supporting rods 21 and the plurality of supporting rods 11 may be all detachably connected, or a part of the supporting rods 11 and the corresponding first supporting rods 21 may be detachably connected. When a plurality of first branch 21 and a plurality of bracing piece 11 are all connected with separable mode, the quantity of first branch 21 is the same with the quantity of bracing piece 11, and each first branch 21 forms the support to each bracing piece 11 respectively for each bracing piece 11 supports respectively and leans on the vascular wall, thereby effectively improves the whole radial strength of filter, makes the stability of filter 100 obtain further improvement, avoids appearing complications such as filter slope, aversion, improves the safety that the patient used.

It is understood that the present embodiment does not limit the specific structure of the second screen 2, for example, in the embodiment shown in fig. 11, the second screen 2 further includes a plurality of second struts 22 distributed around the circumference of the second link 32, one end of the second strut 22 is fixed on the second link 32, and the other end of the second strut 22 extends radially away from the second link 32 and is used for supporting the inner wall of the blood vessel. Due to the complicated structure in the blood vessel, the inner wall of the blood vessel is supported by the second support rod 22 and the support rod 11, so that the filter 100 can be supported and fixed in different planes of the blood vessel, the stability and the like of the filter 100 are further enhanced, and the use safety is ensured. In order to prevent the second struts 22 from piercing the inner wall of the blood vessel, the portions of the second struts 22 that contact the inner wall of the blood vessel are arc-shaped segments that contact the inner wall of the blood vessel at points. Alternatively, in other embodiments, the second screen 2 may also include other rod-like or net-like structures between the first struts 21 and the second links 32, as long as the other rod-like or net-like structures do not contact the inner wall of the blood vessel.

Referring to fig. 12, a third embodiment of the present invention provides a colander which is substantially the same as the colander of the second embodiment except for the detachable connection between the support rods 11 and the first support rods 21.

Referring to fig. 12, the end of the first support bar 21 is provided with a connection ring 211, and the support bar 11 is movably fitted in the connection ring 211. The support rod 11 is inserted through the connection ring 211 when the strainer is in a predetermined configuration. When the filter is collected, the support rod 11 and the connection ring 211 are relatively moved until the support rod 11 is separated from the connection ring 211, thereby releasing the connection between the support rod 11 and the first rod 21.

One end of the support rod 11 far away from the recovery hook 4 is bent and extended towards one side of the longitudinal central axis of the filter to form a lower bent section 111. The lower bent section 111 may facilitate the separation of the support rod 11 from the connection ring 211 during the withdrawal, and the lower bent section 111 may prevent the end of the support rod 11 from stabbing the inner wall of the blood vessel.

If the distance between the two ends of the lower bent section 111 is too large, the support rod 11 is not easily separated from the connection ring 211 when the filter is recovered; if the distance between the two ends of the lower bent section 111 is too small, the support rod 11 is easily separated from the connection ring 211 during the use of the filter, which may affect the supporting function of the first support rod 21 on the support rod 11. Moreover, if the included angle between the connecting line of the two ends of the lower folding section 111 and the longitudinal central axis of the filter is too large, the bending part of the lower folding section 111 is easy to stab the vascular wall; if the angle between the connecting line of the two ends of the lower folding section 111 and the longitudinal central axis of the filter 100 is smaller, the effect of disposing the lower folding section 111 is not significant. Therefore, in this embodiment, the distance between the two ends of the lower folded section 111 is 5mm to 20mm, and the angle between the line connecting the two ends of the lower folded section 111 and the longitudinal central axis of the filter is 20 ° to 60 °. This application is through the distance at 111 both ends of adjustment turn down section simultaneously, and the line at 111 both ends of turn down and the contained angle of the vertical center pin of filter, can be convenient for bracing piece 11 break away from in the go-between 211 when retrieving, and avoid the tip of bracing piece 11 to stab the intravascular wall.

Furthermore, the end of the support rod 11 far from the recovery hook 4 is provided with a spherical part 112 with a smooth outer contour to avoid the end of the support rod 11 from stabbing the inner wall of the blood vessel.

When the support rod 11 is inserted into the connection ring 211, that is, when the first strut 21 is connected to the support rod 11, the end of the first strut 21 remote from the second link 32 can be inserted into the inner wall of the blood vessel to improve the stability of the filter 100 as a whole. Specifically, when the filter 100 is in the predetermined configuration, the end of the first strut 21 remote from the second link 32 passes over the support bar 11, and the difference in height between the end of the first strut 21 remote from the second link 32 and the support bar 11 in the radial direction of the filter is not greater than 5mm to avoid the first strut 21 from puncturing the vessel wall.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The utility model provides a strainer, includes link assembly, and two edges first filter screen and the second filter screen of arranging of axial interval of link assembly, its characterized in that, link assembly includes first connecting rod and the second connecting rod of connecting with separable mode, first filter screen is fixed on the first connecting rod, and towards keeping away from the direction radiation of first connecting rod extends, the second filter screen is fixed on the second connecting rod, and towards keeping away from the direction radiation of second connecting rod extends, first filter screen includes a plurality of bracing pieces that are used for supporting on the vascular inner wall, the bracing piece with the free end contact of second filter screen links to each other, and separable.

2. The colander of claim 1, wherein a locking mechanism is disposed between the first and second links, the first and second links being slidable relative to one another when the locking mechanism is unlocked.

3. The colander of claim 1 further comprising two retrieval hooks disposed on each of the first and second rods.

4. A filter as claimed in claim 1, in which the second screen comprises first struts which are detachably connected to the support rods.

5. The colander of claim 4, wherein the support rods are secured to the first rod and each extend radially away from the first rod.

6. The colander of claim 4, wherein the first screen further comprises a plurality of tie bars, one end of the tie bars being fixed to the first tie bar and the other end of the tie bars being connected to the support bar.

7. The colander of claim 4, wherein the number of the first struts is a plurality, and a plurality of the first struts are distributed around the circumference of the connecting rod assembly, and the first struts are fixed to the second connecting rod and extend radially away from the second connecting rod.

8. The filter of claim 4, wherein the second screen further comprises second struts, one ends of the second struts being fixed to the second links, and the other ends of the second struts extending radially away from the second links and being adapted to support the inner wall of the vessel.

9. A filter as claimed in claim 4, wherein one end of the support rod is bent towards one side of the longitudinal central axis of the filter to form a lower bend.

10. The filter of claim 9, wherein the distance between the two ends of the lower folded section is 5mm to 20mm, and the included angle between the connecting line of the two ends of the lower folded section and the longitudinal central axis of the filter is 20 ° to 60 °.