CN113633431A

CN113633431A - Filter device

Info

Publication number: CN113633431A
Application number: CN202010393727.6A
Authority: CN
Inventors: 朱清; 朱永锋; 张兆夺; 屠春霖
Original assignee: Shanghai Lanmai Medical Technology Co ltd
Current assignee: Shanghai Lanmai Medical Technology Co ltd
Priority date: 2020-05-11
Filing date: 2020-05-11
Publication date: 2021-11-12
Also published as: AR122064A1; WO2021227611A1

Abstract

The invention provides a filter, comprising a filter component, a support component and a degradable constraint component; one end of the filter component is connected with the supporting component, and the other end of the filter component is connected with the restraining component; the filter component is coaxially arranged with the support component; the restricting member gathers the end of the filter member and has an opening. The filter provided by the invention can solve the problems of filter fracture, filter puncture of the blood vessel wall, filter displacement or inferior vena cava blockage and the like when the existing recyclable filter is converted into a permanent filter.

Description

Filter device

Technical Field

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

Background

Venous Thromboembolism (VTE) is a common disease in clinic, and has high morbidity and mortality. VTEs include Deep Vein Thrombosis (DVT) and pulmonary artery embolism (PE). DVT often occurs in the veins of the lower extremities, while PE is primarily caused by the shedding of thrombi into the pulmonary arteries following the formation of a thrombus in the venous system or right heart, and is a leading cause of morbidity and mortality.

Anticoagulation has been the gold standard for VTE therapy with the goal of preventing thrombosis, preventing PE, and restoring patency of embolic veins. When a patient has anticoagulation contraindication or bleeding complications occur, anticoagulation has to be stopped, the falling thrombus can be effectively intercepted by implanting a Vena Cava Filter (VCF for short), and the occurrence of lethal pulmonary embolism can be prevented. Early vena cava filters were primarily permanent filters, which had the disadvantage of being prone to complications such as occlusion of the inferior vena cava at a long term.

In recent years, recyclable vena cava filters have become mainstream, and patients can recycle the filters after the risk of PE is relieved, thereby avoiding complications caused by long-term implantation of the filters. There are, however, instances in the clinic where a large number of recoverable filters are not recovered within a time window and are converted to permanent filter use. The conversion of a recyclable filter to a permanent filter may present problems such as filter breakage, filter puncture of the vessel wall, filter dislodgement, and occlusion of the inferior vena cava.

Disclosure of Invention

The invention aims to solve the technical problems of filter fracture, filter puncture of the vessel wall, filter displacement or inferior vena cava blockage and the like when a recyclable filter is converted into a permanent filter.

In order to solve the above technical problems, the present invention provides a filter comprising a filter member, a support member and a degradable restriction member; one end of the filter component is connected with the supporting component, and the other end of the filter component is connected with the restraining component; the filter component is coaxially arranged with the support component; the restricting member gathers the end of the filter member and has an opening.

Alternatively, in the strainer, a plurality of coupling holes are provided at an end portion of the filtering member, and the restricting member is passed through the plurality of coupling holes to gather the end portion of the filtering member and have an opening.

Optionally, in the filter, on a radial cross section of the filter, projections of the plurality of connection holes enclose a circumference, and at an intersection point of the connection holes and the circumference, an included angle between the connection holes and a tangent of the circumference ranges from 45 ° to 135 °.

Optionally, in the filter, the area of the openings is in the range of 2.25 π mm²～16πmm²。

Optionally, in the filter, the filter element comprises a first filter element and a second filter element, the support element has opposite proximal and distal ends, and the first filter element is connected to the proximal end of the support element; the second filter component is connected with the distal end of the support component;

the restricting member includes a first restricting member and a second restricting member; the first restraining component draws the first filter component and enables the end part of the first filter component to be provided with a first opening; the second restraining element gathers the second filter element and enables the end of the second filter element to be provided with a second opening.

Optionally, in the filter, the first opening is circular and the first opening is perpendicular to an axial direction of the filter.

Optionally, in the filter, the second opening is elliptical, and an included angle between the second opening and an axial direction of the filter is in a range of 10 ° to 70 °.

Optionally, in the filter, the second filtering component includes a plurality of filtering rods, the lengths of the plurality of filtering rods are different in the axial direction of the filter, and the length difference range of any two filtering rods is 1mm to 4 mm.

Optionally, in the filter, the filter rods are Y-shaped filter rods, and a plurality of the Y-shaped filter rods are distributed along the circumferential direction of the filter.

Optionally, in the filter, a recovery part is arranged at one end of the second filter part far away from the support part.

Optionally, in the filter, the filter further comprises a plurality of support bodies connected to the support member, each of the support bodies comprising an extension section and a support section connected to the extension section.

Optionally, in the strainer, the extension extends from a junction with the support member in a direction away from the support member and is inclined toward the first filter member.

Optionally, in the filter, the extension extends in a direction away from or towards the first filter element; or part of the extension sections extend towards the direction far away from the first filter component, and the rest of the extension sections extend towards the direction close to the first filter component.

Optionally, in the strainer, the support section extends in a direction away from the first filter element, and the support section is curved toward the support element.

Optionally, in the strainer, the support section is provided with an anchor spike extending in a direction close to the support member and inclined toward the first filter member.

Optionally, in the strainer, the support member is provided with an anchor spike, the anchor spike extends away from the support member and is inclined towards the first filter member; in the radial direction of the support member, the extension length of the anchor spike is greater than the extension length of the support body.

Optionally, in the strainer, the anchoring spike is provided with a blocking member extending from a connection with the anchoring spike in a direction close to the support member.

Compared with the prior art, the filter provided by the invention has the following advantages:

1) before the restraining component is degraded, the filter component cannot be wrapped by thrombus and fiber objects due to the opening at the end part of the filter component; after degradation of the restriction device, the filter is converted from the filter configuration to a stent configuration, thereby avoiding a long-term complication.

2) On the radial section of the filter, the projection of the connecting holes encloses a circle, at the intersection point of any connecting hole and the circle, the included angle range of the connecting hole and the tangent line of the circle is 45-135 degrees, and in the angle range, the friction force between the constraint component and the connecting hole is small, so that the fracture time of the degradable constraint component can be delayed, the risk that the filter is converted from the filter configuration to the support configuration in advance due to the early fracture of the constraint component is avoided, and the stability of the filter conversion time is improved.

3) The support body is arranged outside the filter, and the inner wall of the blood vessel is in contact with the support section of the support body but not with the main body of the filter, so that the wrapping degree of the blood vessel hyperplasia on the filter is reduced, and the recovery time window of the filter can be prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of a first construction of a strainer according to an embodiment of the present invention;

FIG. 2 is a perspective view of the restricting member of FIG. 1;

FIG. 3 is a schematic diagram of a second construction of a strainer in accordance with an embodiment of the present invention;

FIG. 4 is an enlarged view taken at A in FIG. 3;

FIG. 5 is a schematic view of a third construction of a filter according to an embodiment of the invention;

FIG. 6 is a schematic diagram of a fourth configuration of a filter in an embodiment of the invention;

FIG. 7 is a schematic diagram of a fifth construction of a strainer in accordance with an embodiment of the present invention;

FIG. 8 is a schematic diagram of a sixth configuration of a strainer in accordance with an embodiment of the present invention;

FIG. 9 is an enlarged view at B in FIG. 8;

FIG. 10 is a schematic view of a seventh construction of a strainer according to an embodiment of the present invention;

FIG. 11 is a schematic view of a filter implanted in a blood vessel with a restriction member undegraded in accordance with an embodiment of the present invention;

FIG. 12 is a schematic view of a filter implanted in a blood vessel with a restriction member degraded in accordance with an embodiment of the present invention;

wherein the reference numbers are as follows:

100-a filter element; 101-a first filter element; 102-a second filter element; 103-opening; 103' -a second opening; 104-connection hole;

200-a support member;

300-a constraining member; 301-a first filter element; 302-a second filter component;

400-a recovery component;

500-a support; 501-an extension section; 502-a support section;

600-anchoring thorn;

700-a barrier;

800-vessel wall.

Detailed Description

The filter according to the invention is described in more detail below with reference to the figures and the description. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are all used in a non-precise scale for the purpose of facilitating and distinctly aiding in the description of the embodiments of the present invention. To make the objects, features and advantages of the present invention comprehensible, reference is made to the accompanying drawings. It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the implementation conditions of the present invention, so that the present invention has no technical significance, and any structural modification, ratio relationship change or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention.

"proximal" and "distal" are defined herein as: "proximal" generally refers to the end of the medical device that first enters the patient during normal operation, and "distal" generally refers to the end of the medical device that is near the operator during normal operation.

The filter provided by the invention can be suitable for intercepting thrombus in vena cava blood vessels, and can also be used in other types of blood vessels, and the invention is not limited to the filter.

Example one

The invention provides a filter, which comprises a filter component, a support component and a degradable constraint component. Referring to fig. 1, a first structural diagram of a filter according to an embodiment of the present invention is schematically shown, wherein the filter includes two filter members 100, a support member 200, and a degradable constraint member 300. One end of the filter element 100 is connected to the support element 200, and the other end is connected to the constraining member 300, the filter element 100 is coaxially disposed with the support element 200, and the constraining member 300 gathers the end of the filter element 100 and provides it with an opening 103.

In this embodiment, the restraining member 300 does not close the ends of the filter element 100, but leaves the openings 103 at the ends of the filter element 100, thereby preventing thrombus or fiber wrapping at the ends of the filter element 100, and the filter can be smoothly transformed from the filter configuration to the stent configuration after the restraining member 300 is degraded, thereby preventing a long-term complication.

Specifically, as shown in fig. 1, the end of the filter element 100 is provided with a plurality of connecting holes 104, so that the restricting member 300 can pass through the plurality of connecting holes 104 to close the end of the filter element 100 and provide it with an opening 103. Preferably, as shown in fig. 2, in a radial section of the strainer, a projection of the plurality of connecting holes 104 encloses a circumference, and at an intersection of the connecting holes 104 and the circumference, the connecting holes 104 form an angle β with a tangent of the circumference, the angle β preferably ranging from 45 ° to 135 °. It is understood that if the angle β is less than 45 ° or greater than 135 °, for example, 0 °, the friction between the restriction member 300 and the connection hole 104 is large, so that when the filter is periodically compressed in the radial direction of the blood vessel, the connection hole 104 may periodically damage the restriction member 300, thereby accelerating the fracture of the restriction member 300, and the filter is prematurely transformed from the filter configuration to the stent configuration, and the detached thrombus cannot be captured, thereby reducing the stability of the filter transformation time.

As shown in fig. 1 and 2, the end portions of both filter members 100 have openings 103, the openings 103 are circular, and the openings 103 are perpendicular to the axial direction of the filter. The area range of the opening 103 is preferably 2.25 pi mm²～16πmm²I.e. the openingThe diameter D of 103 preferably ranges from 3mm to 8 mm. The reason why the diameter of the opening 103 is set to 3-8 mm is that: if the diameter is too small, the risk of being wrapped by thrombus or fiber still exists, and if the diameter is too large, the fallen thrombus cannot be effectively intercepted.

Specifically, the filter member 100 includes a plurality of filter rods, and the filter rods are equal in length in the axial direction of the filter. In this embodiment, the filter rods may be Y-shaped filter rods, and a plurality of the Y-shaped filter rods are distributed along the circumferential direction of the filter. Each Y-shaped filter rod comprises a main branch section and two branch sections separated from one end of the main branch section, the two branch sections are connected with the support component 200, and the other end of the main branch section is provided with the connecting hole 104. The restricting member 300 sequentially passes through the connecting hole 104 at the other end of the main branch section of each Y-shaped filter rod, thereby gathering the other end of the main branch section of each Y-shaped filter rod and forming the opening 103.

Example two

Referring to fig. 3, a second schematic diagram of a filter according to an embodiment of the present invention is schematically shown, the filter includes a first filter element 101 and a second filter element 102, the support element 200 has a proximal end and a distal end opposite to each other, the first filter element 101 is connected to the proximal end of the support element 200, and the second filter element 102 is connected to the distal end of the support element 200; the restricting member 300 includes a first restricting member 301 and a second restricting member 302, the first restricting member 301 draws the first filter element 101 and provides the end of the first filter element 101 with a first opening, and the second restricting member 302 draws the second filter element 102 and provides the end of the second filter element 102 with a second opening 103'. In addition, the end of the second filter element 102 away from the support element is further provided with a recovery element 400, such as a recovery hook, the recovery element 400 being used for being caught by a catcher and locked when the filter is recovered, so as to recover the filter.

In this embodiment, the first opening is circular and perpendicular to the axial direction of the filter, and the diameter range of the first opening is 3mm to 8mm, which is the same as the opening 103 in the first embodiment, and is not described herein again. Specifically, the first filter part 101 includes a plurality of filter rods, each filter rod may be a Y-shaped filter rod, the plurality of Y-shaped filter rods are distributed along the circumferential direction of the filter, each Y-shaped filter rod includes a main branch section and two branch sections separated from one end of the main branch section, the two branch sections are connected to the proximal end of the support part 200, the other end of the main branch section is provided with a connection hole, and the first constraint part 301 sequentially passes through the connection holes at the other end of the main branch section of each Y-shaped filter rod, so as to collect the other end of the main branch section of each Y-shaped filter rod and form the first opening. Wherein, in the axial direction of the filter, a plurality of the filter rods are of equal length.

Referring to fig. 4, the second opening 103' is oval and not perpendicular to the axial direction of the filter, but forms an angle α, which is acute and preferably 10-70 °. Preferably, the area of the second opening 103' is in the range of 2.25 pi mm²～16πmm²I.e. the area corresponding to a circle with a diameter of 3mm-8 mm. Specifically, the second filter component 102 includes a plurality of filter rods, which may be Y-shaped filter rods, the plurality of Y-shaped filter rods are distributed along the circumferential direction of the filter, each Y-shaped filter rod includes a main branch section and two branch sections branched from one end of the main branch section, the two branch sections are connected to the distal end of the support component 200, the other end of the main branch section is provided with a connection hole 104, and the second constraint component 302 sequentially passes through the connection holes 104 of the other ends of the main branch sections of the respective Y-shaped filter rods, so as to collect the other ends of the main branch sections of the respective Y-shaped filter rods and form the second opening 103'. In the axial direction of the filter, the lengths of the plurality of filter rods are different, and the length difference range of any two filter rods is 1-4 mm.

It should be noted that the number of filter rods included in the first filter element 101 and the second filter element 102 may be the same or different, and the present invention is not limited thereto.

Referring to fig. 4, in the present embodiment, the filter rods of the second filter element 102 are set to have different lengths, so that on one hand, the second filter element 102 is folded by the second constraint element 302 to form the second opening 103'; on the other hand, the lengths of the respective filter rods of the second filter element 102 are different in the axial direction of the filter, and the recovery member 400 is provided at the end of the longest filter rod away from the support member 200, so that the sheath tube is prevented from being caught at the end of the second filter element 102 away from the support member 200 during filter recovery.

EXAMPLE III

In this embodiment, a plurality of supporting bodies 500 may be further disposed on the outside of the filter, as shown in fig. 5 to 7, the supporting bodies 500 extend outward from the outside of the filter and abut against the inner wall of the blood vessel, so that the inner wall of the blood vessel contacts only the supporting bodies 500 and does not contact with the main body of the filter (including the supporting member 200, the first filtering member 101, and the second filtering member 102), thereby reducing the degree of wrapping of the filter by the blood vessel hyperplasia and further prolonging the recovery time window of the filter. Meanwhile, by providing the support body 500, the contact area with the inner wall of the blood vessel is reduced, and thus the filter can be easily taken out.

Specifically, a plurality of the supporting bodies 500 are connected to the supporting member 200, each of the supporting bodies 500 comprises an extension section 501 and a supporting section 502 connected to the extension section, the extension section 501 extends from the connection with the supporting member 200 to the outside of the filter, and the supporting section 502 can abut against the inner wall of the blood vessel after being implanted in the blood vessel.

Specifically, in one implementation, as shown in fig. 5, the extension 501 extends from the connection point with the support member 200 to a direction away from the support member 200, and is inclined toward the first filter member 101. In addition, the support section 502 may extend in a direction toward the first filter member 101. In one implementation, the extension 501 extends outward for a certain distance, and then the support section 502 extends in a direction parallel to the axial direction of the filter, so that the support section 502 can abut against the inner wall of the blood vessel after the filter is implanted in the body and support the inner wall of the blood vessel to isolate the inner wall of the blood vessel from contacting the main body part of the filter. Meanwhile, the contact area between the support section 502 and the inner wall of the blood vessel is small, so that the filter can be conveniently taken out, and the damage to the inner wall of the blood vessel is small. Alternatively, the support section 502 may extend away from the first filter element 101, and the support section 502 is bent toward the support element 200, in which case, the support section 502 is arc-shaped, and has a smaller contact area with the inner wall of the blood vessel, so that the inner wall of the blood vessel is less damaged.

In another implementation, the extension 501 may extend away from or close to the first filter element 101, for example, in an arc shape. Or a part of the extension 501 extends in a direction away from the first filter element 101, and the rest of the extension 501 extends in a direction close to the first filter element 101, as shown in fig. 6, the extension 501 first extends in a direction away from the first filter element 101 and then extends in a direction close to the first filter element 101, so that the extension 501 forms an arc shape, and the support section 502 extends in a direction away from the first filter element 101, and the support section 101 is bent toward the support member 200, so that the support body 500 is in a curled shape, and not only the contact area with the inner wall of the blood vessel is smaller, and therefore, the damage to the inner wall of the blood vessel is also smaller, but also the support strength to the blood vessel wall is improved.

Preferably, the radial height difference between the position of the support body 500 farthest from the central axis of the filter and the position of the support member 200 having the largest outer diameter is in the range of 1mm to 4 mm. Fig. 5 and 6 each show two dimensions D1 and D2, wherein D2 is the maximum outer diameter of the support element 200, the position of the support body 500 furthest away from the central axis of the filter is the distance between the support section 502 and the central axis of the filter, and the distance between the support section 502 furthest away from the central axis of the filter and the central axis of the filter in the radial direction of the filter is equal to half the dimension D1. That is, in the radial direction of the filter, D2 represents the maximum outer diameter of the filter when the support 500 is not included, D1 represents the maximum outer diameter of the filter when the support 500 is included, and the range of the difference between D1 and D2 is preferably 2mm to 8 mm.

In other embodiments, as shown in fig. 5, a plurality of supports 500 may be separately provided on the outside of the filter; as shown in fig. 6, a plurality of the support bodies 500 may be separately provided on the outside of the filter; as shown in fig. 7, the two kinds of the support bodies 500 may be mixedly disposed outside the filter. The plurality of supporting bodies 500 may be uniformly distributed outside the filter as long as the contact between the main body portion of the filter and the inner wall of the blood vessel can be avoided, and the specific form and the installation position of the plurality of supporting bodies 500 are not limited in this embodiment.

In this embodiment, the filter may be provided with anchoring barbs on the outside thereof, which are provided for the purpose of: after the filter is implanted into a blood vessel, the anchor can be inserted into the inner wall of the blood vessel, thereby preventing the filter from being displaced.

In one implementation, as shown in fig. 8 and 9, an anchor 600 is disposed on the supporting body 500, specifically, an anchor 600 is disposed on the supporting section, and the anchor 600 extends toward the supporting member 200 and inclines toward the first filter member 101. It will be appreciated that the first filter component 101 first enters the blood vessel when implanted, such that the anchoring spike 600 is directed against the blood flow when the filter is implanted in the body, such that the anchoring spike 600 facilitates penetration of the inner wall of the blood vessel when the filter is implanted, and such that the anchoring spike 600 does not present an obstacle when the filter is retrieved.

In another implementation, as shown in fig. 10, the anchoring spike 600 may also be directly disposed on the support member 200, the anchoring spike 600 extending away from the support member 200 and being inclined towards the first filter member 101. Meanwhile, the extension length of the anchor 600 should be greater than that of the support body 500 in the radial direction of the support member 200.

The anchoring thorn 600 extends straight outwards from the connection with the support member 200 in a direction towards the filter member that first enters the blood vessel, in fig. 10 the first filter member 101 is the filter member that first enters the blood vessel, whereby the anchoring thorn 600 extends straight outwards in a direction towards the first filter member 101.

In some embodiments, such as the filter shown in fig. 8, the anchoring spike 600 may be provided only on the support 500; as in the filter shown in fig. 10, the anchoring thorn 600 may be provided only outside the supporting member 200; the anchoring thorn 600 may also be provided on the support body 500 and outside the support member 200 at the same time. In some embodiments, the anchoring spike 600 may be disposed on each support body 500, or the anchoring spike 600 may be disposed on a part of the support body 500, as long as the filter is prevented from being displaced, which is not limited by the present invention.

Further, the anchoring thorn 600 is further provided with a blocking member 700, and the blocking member 700 is used for limiting the penetration limit of the anchoring thorn 600 into the blood vessel wall at the junction of the anchoring thorn 600 and the blocking member 700, so as to limit the penetration depth of the anchoring thorn 600 into the blood vessel wall. As shown in fig. 9, the blocking member 700 extends from the connection with the anchor 600 towards the support member.

Referring to fig. 11 and 12, the effect of the filter provided by the present invention implanted in a blood vessel is shown. First, before the first and

second restriction members

301 and 302 are degraded, since the ends of the first and

second filter members

101 and 102 have openings, the ends of the first and

second filter members

101 and 102 are not wrapped by thrombus and fiber, and the first and

second restriction members

301 and 302 can be degraded smoothly, so that the filter can be smoothly converted from the filter configuration to the stent configuration. Secondly, on the radial section of the filter, the projection of the connecting holes encloses a circle, at the intersection point of any connecting hole and the circle, the included angle range of the connecting hole and the tangent line of the circle is 45-135 degrees, and in the angle range, the friction force between the restraining component and the connecting holes is small, so that the fracture time of the degradable restraining component can be delayed, the risk that the filter is converted from the filter configuration to the support configuration in advance due to the early fracture of the restraining component is avoided, and the stability of the filter conversion time is improved. In addition, the supporting body 500 is arranged outside the filter, the blood vessel wall 800 is contacted with the free end of the supporting body 500, but not contacted with the main body part of the filter, the wrapping degree of the vascular hyperplasia to the filter is reduced, and the recovery time window of the filter can be prolonged.

The filter provided by the invention is suitable for patients needing temporary filter protection, and the filter can be treated in two ways after being implanted into blood vessels of patients:

firstly, the filter can be recovered for a patient with basically eliminated PE risk in a short period, required to be taken out and low operation risk, the function of the filter is the same as that of the traditional recoverable filter, and no permanent implant is left in the patient;

second, for patients who have a short period of time in which the risk of PE cannot be relieved, or who are unwilling to undergo filter recovery surgery, the filter will not be recovered. The filter will remain in the patient in the filter configuration for a sufficient time, after which the degradation line at the end of the filter (i.e., the restraining member 300) is broken, the filter is converted to the stent configuration, and the patient lumen is open.

In summary, the filter provided by the invention has the following advantages: 1, the degradable conversion filter can be prevented from being incapable of degrading and converting due to the coating of thrombus or fiber; 2, the stability of the conversion time of the restraint component is improved to the maximum extent; and 3, prolonging the time window of filter recovery.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications may be made in the invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A filter comprising a filter member, a support member and a degradable restriction member; one end of the filter component is connected with the supporting component, and the other end of the filter component is connected with the restraining component; the filter component is coaxially arranged with the support component; the restricting member gathers the end of the filter member and has an opening.

2. The strainer of claim 1 wherein the end portion of the filter element is provided with a plurality of attachment holes and the restraining element is passed through the plurality of attachment holes to gather the end portion of the filter element and provide it with an opening.

3. The strainer of claim 2 wherein, in a radial cross-section of the strainer, a projection of the plurality of attachment holes defines a circle, and wherein at an intersection of the attachment holes and the circle, the attachment holes are angled from a line tangent to the circle in a range of 45 ° to 135 °.

4. A filter as claimed in claim 1, characterised in that the openings have an area in the range of 2.25 pi mm²～16πmm²。

5. The filter of claim 1, wherein the filter element comprises a first filter element and a second filter element, the support element having opposing proximal and distal ends, the first filter element being coupled to the proximal end of the support element; the second filter component is connected with the distal end of the support component;

6. The strainer of claim 5 wherein the first openings are circular and the first openings are perpendicular to an axial direction of the strainer.

7. A filter as claimed in claim 5, wherein the second openings are elliptical and the second openings are angled in the range 10 ° to 70 ° to the axial direction of the filter.

8. The filter of claim 5, wherein the second filter element comprises a plurality of filter rods, the plurality of filter rods are different in length in an axial direction of the filter, and a length difference between any two of the filter rods ranges from 1mm to 4 mm.

9. The strainer of claim 8 wherein said filter rods are Y-shaped filter rods, a plurality of said Y-shaped filter rods being circumferentially distributed about said strainer.

10. A filter as claimed in claim 5, wherein the end of the second filter element remote from the support element is provided with a recovery element.

11. The strainer of claim 5 further comprising a plurality of support bodies connected to said support member, each of said support bodies comprising an extension section and a support section connected to said extension section.

12. The strainer of claim 11 wherein the extension extends from a connection with the support member in a direction away from the support member and is inclined toward the first filter member.

13. The strainer of claim 11 wherein the extension extends in a direction away from or toward the first filter member; or part of the extension sections extend towards the direction far away from the first filter component, and the rest of the extension sections extend towards the direction close to the first filter component.

14. The strainer of claim 11 wherein the support sections extend away from the first filter element and the support sections are curved toward the support elements.

15. A filter according to claim 11, wherein the support section is provided with anchoring barbs extending in a direction towards the support member and inclined towards the first filter element.

16. A filter according to claim 11, wherein the support member is provided with anchoring barbs extending away from the support member and inclined towards the first filter element; in the radial direction of the support member, the extension length of the anchor spike is greater than the extension length of the support body.

17. A strainer according to claim 15 or 16 wherein the anchoring barbs are provided with stop members extending from their connection to the anchoring barbs towards the support member.