CN105662646A

CN105662646A - Filter

Info

Publication number: CN105662646A
Application number: CN201511024970.6A
Authority: CN
Inventors: 李安宁; 兰娟
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2015-12-29
Filing date: 2015-12-29
Publication date: 2016-06-15
Also published as: WO2017113633A1

Abstract

The invention discloses a filter. The filter mainly comprises a proximal end filter screen and a distal end filter screen, and the conicity of the proximal end filter screen close to the proximal end is smaller than that of the distal end filter screen close to the distal end. Hence, the radial support force of the proximal end filter screen is smaller than that of the distal end filter screen. When an embolus is intercepted by the proximal end filter screen, the radial support force of the proximal end filter screen is increased, the difference between the radial support force of the proximal end filter screen and the radial support force of the distal end filter screen is reduced, filter is not liable to tilt, the embolus filtering efficiency of the filter is improved, and the risk that the patient suffers from embolism again is reduced.

Description

Filter

Technical field

The present invention relates to a kind of implanted medical device, particularly relate to a kind of filter.

Background technology

Pulmonary infarction (is called for short: PE) refer to that the various emboluses that body circulate come off and block pulmonary artery and branch thereof and cause the clinical pathology physiology syndrome of disturbance of pulmonary circulation, have sickness rate height, morbidity urgency, case fatality rate high. Having statistics, the pulmonary infarction mortality rate without treatment is 20～30%, and annual new cases accounts for the 0.2% of population, calculates according to China 13.5 hundred million population, there are about 2,700,000 newly-increased patients every year.

The various emboluses of body circulation come off and all can cause pulmonary infarction. Modal embolus is thrombosis. The formative factor of thrombosis has multiple, including: wound or fracture, wound, bigger operation, large-area burns, gestation, childbirth, prolonged illness bed, long-distance by bus or aircraft sitting is motionless, sit quietly for a long time and squat down. These thrombosis are general and the slight adhesion of tube wall, it is easy to come off. The free embolus come off can cause the serious change such as pulmonary infarction. Filter is proved to be the safely and effectively means of prevention pulmonary infarction clinically, it is possible to decrease the incidence rate of pulmonary infarction. Filter is implanted in postcava, it is prevented that the thrombosis that lower limb come off arrives pulmonary along blood flow, thus preventing pulmonary infarction.

Existing filter, when embolus is intercepted in proximal part filter screen, easily occurs crooked. And the efficiency of crooked frit embolus reduces, add the risk of postoperative sufferer thromboembolism again.

Summary of the invention

It is an object of the invention to, for above-mentioned the deficiencies in the prior art, it is provided that a kind of filter. Filter of the present invention is near the tapering of the proximal part drainage screen of filter proximal part less than the tapering of distal end drainage screen near filter distal end, and the radial direction support force of proximal part drainage screen is less than the radial direction support force of distal end drainage screen. When embolus is intercepted in proximal part drainage screen, the radial direction support force of proximal part drainage screen increases, reduce the gap between the radial direction support force of proximal part drainage screen and the radial direction support force of distal end drainage screen, reduce the possibility that filter is crooked, improve the efficiency of frit embolus, reduce the risk of postoperative sufferer thromboembolism again.

The present invention provides a kind of filter, it main part including having relative proximal part and distal end. Described main part includes between described proximal part and distal end and the proximal part drainage screen that is connected and distal end drainage screen. When described filter Spontaneous release, described proximal part drainage screen and distal end drainage screen are the space pyramidal structure that a plurality of netting twine is constituted. The tapering of described proximal part drainage screen is less than the tapering of described distal end drainage screen.

Wherein in an embodiment, described proximal part drainage screen includes a multiple connected Y type unit.Each Y type unit all includes the first netting twine and two article of second netting twine extended to form by described first netting twine bifurcated at one end. Described a plurality of first netting twine of multiple described Y type unit converges at described proximal part place. Described second netting twine of each described Y type unit is all connected with described distal end drainage screen away from the end of proximal part.

Wherein in an embodiment, when described filter Spontaneous release, described first netting twine in an arbitrary described Y type unit and the junction point of the second netting twine are 1:10 to 7:16 to the ratio range of distance and the size at described filter largest outside diameter place on the longitudinal center's direction of principal axis being perpendicular to described filter of the vertical central axis of described filter.

Wherein in an embodiment, often two articles of described first netting twines of adjacent two described Y type unit and adjacent two article second netting twine of corresponding two described Y type unit enclose one the first rhombus filter element of formation. When described filter Spontaneous release, the area ratio of the multiple first rhombus filter elements of described filter projected area on the cross section of vertical central axis being perpendicular to described filter and the circle corresponding to described filter maximum outside diameter on the longitudinal center's direction of principal axis being perpendicular to described filter ranges for 1:10 to 9:10.

Wherein in an embodiment, described distal end drainage screen includes multiple the 2nd connected Y type unit. Each 2nd Y type unit all includes the 3rd netting twine and two article of the 4th netting twine extended to form by described 3rd netting twine bifurcated at one end. A plurality of 3rd netting twine of multiple described 2nd Y type unit converges at described distal end place. Each 2nd Y type unit described 4th netting twine be all connected with described proximal part drainage screen away from the end of described distal end.

Wherein in an embodiment, when described filter Spontaneous release, described 3rd netting twine in arbitrary described 2nd Y type unit and the junction point of the 4th netting twine are 1:10 to 7:16 to the ratio range of the size at described filter largest outside diameter place on the longitudinal center's direction of principal axis being perpendicular to described filter after distance and the described filter Spontaneous release of the vertical central axis of described filter.

Wherein in an embodiment, described distal end drainage screen includes a plurality of linear 5th netting twine. Described a plurality of 5th netting twine converges at described distal end place near the end of described distal end. The end away from described distal end of every described 5th netting twine is all connected with described supporting section.

Wherein in an embodiment, described main part also includes the supporting section being connected between described proximal part drainage screen and distal end drainage screen. Described supporting section includes many straight-bars. Described straight-bar is roughly parallel to the vertical central axis of described filter.

Wherein in an embodiment, the quantity of described straight-bar is many, and the length of many described straight-bars is identical.

Wherein in an embodiment, described straight-bar along the width of the circumferential direction of described filter more than arbitrary netting twine of described proximal part drainage screen and described distal end drainage screen along the width of the circumferential direction of described filter.

Wherein in an embodiment, described supporting section also includes at least one shaped form bar. One end of described shaped form bar is connected with described proximal part drainage screen, and the other end is connected with described distal end drainage screen.

Wherein in an embodiment, described straight-bar and described shaped form bar are spaced apart in the circumferencial direction of described filter.

Wherein in an embodiment, described straight-bar and described shaped form bar are not spaced apart in the circumferencial direction of described filter.

Wherein in an embodiment, at least one described straight-bar is provided with at least one fixing anchor for fixing described filter. One end of described fixing anchor is fixed on described straight-bar, and the other end of described fixing anchor is free end and extends to the direction of described proximal part.

Wherein in an embodiment, the angle between described fixing anchor and the described straight-bar being directly connected is less than 90 degree.

Wherein in an embodiment, the vertical dimension of the described straight-bar that the free end of described fixing anchor is joined directly together to the described fixing anchor with its place is less than or equal to 3 millimeters.

Wherein in an embodiment, described filter also includes recovering hook. Described recovering hook is arranged at distal end or the proximal part of described main part. Described recovering hook is the tubular structure with an opening. The opening direction of described recovering hook stretches out along the radial direction of described filter and offsets towards described main part. The opening of described recovering hook the width being perpendicular on described opening direction more than or equal to described recovering hook tubular structure outside dimension 1/5. The opening of the described recovering hook degree of depth on the longitudinal center's direction of principal axis being perpendicular to described filter less than or equal to described recovering hook tubular structure outside dimension 19/20.

Wherein in an embodiment, the material of described filter is Nitinol. Described filter forms the netting twine of described proximal part drainage screen and described distal end drainage screen by cutting on NiTi pipe, and carries out sizing and form.

The present invention compared with prior art, has the advantages that

The present invention is near the tapering of the proximal part drainage screen of filter proximal part less than the tapering of distal end drainage screen near filter distal end, and the radial direction support force of proximal part drainage screen is less than the radial direction support force of distal end drainage screen. When embolus is intercepted in proximal part filter screen, the radial direction support force of proximal part drainage screen increases, reduce the gap between the radial direction support force of proximal part drainage screen and the radial direction support force of distal end drainage screen, reduce the possibility that filter is crooked, improve the efficiency of frit embolus, reduce the risk of postoperative sufferer thromboembolism again.

Accompanying drawing explanation

Fig. 1 a-Fig. 1 b is the overall structure schematic diagram of the filter of first embodiment of the invention, the main part of described filter includes proximal part drainage screen, distal end drainage screen and connects the supporting section of described proximal part drainage screen and distal end drainage screen, and described proximal part drainage screen includes multiple first rhombus filter element; Wherein, Fig. 1 a is axonometric chart, and Fig. 1 b is front view;

Fig. 1 c is the sectional view on the cross section of vertical central axis with filter of the filter described in Fig. 1 a;

Fig. 1 d is the partial structurtes front view of the main part of filter described in Fig. 1 a;

Fig. 1 e is the proximal part drainage screen of filter described in Fig. 1 a projection on the cross section of vertical central axis being perpendicular to filter;

Fig. 1 f is the area ratio schematic diagram of the multiple first rhombus filter elements of filter described in Fig. 1 a projected area on the cross section of vertical central axis being perpendicular to described filter and the circle corresponding to described filter external diameter on the longitudinal center's direction of principal axis being perpendicular to described filter;

Fig. 1 g is the distal end drainage screen of filter described in Fig. 1 a projection on the cross section of vertical central axis being perpendicular to filter;

Fig. 2 is the structural representation of the recovering hook of the filter in Fig. 1 a;

Fig. 3 is the structural representation of the fixing anchor of the filter in Fig. 1 a;

Fig. 4 is the schematic diagram that the filter in Fig. 1 a rotates around fixing anchor;

Fig. 5 a-Fig. 5 b is the overall structure schematic diagram of the filter of second embodiment of the invention, and the main part of described filter includes proximal part drainage screen, distal end drainage screen and connects the supporting section of described proximal part drainage screen and distal end drainage screen;Wherein, Fig. 5 a is axonometric chart, and Fig. 5 b is front view;

Fig. 5 c is the partial structurtes front view of the main part of filter described in Fig. 5 a;

Fig. 5 d is the distal end drainage screen of filter described in Fig. 5 a projection on the cross section of vertical central axis being perpendicular to filter;

The filter implantation postcava that Fig. 6 is comparative example one took out after 14 days, described inferior caval developed image.

Detailed description of the invention

In order to make the purpose of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated. Should be appreciated that specific embodiment described herein is only in order to explain the present invention, is not intended to limit the present invention.

Unless otherwise defined, all of technology used herein is identical with the implication that the those skilled in the art belonging to the present invention are generally understood that with scientific terminology. The term used in the description herein is intended merely to the purpose describing specific embodiment, it is not intended that in the restriction present invention.

Clear in order to describe, below one end that filter flows out filter near heart, blood is called proximal part, one end that filter flows into filter away from heart, blood is called distal end.

Technical scheme is further described below with reference to specific embodiment.

Embodiment one

The cutting of NiTi pipe, sizing that in the present embodiment, the main part of filter adopts outside dimension to be 0.2-4mm form. Being appreciated that filter can be also 0.05-0.5mm by the titanium-nickel wire that outside dimension is 0.05-0.8mm or width, the NiTi bandlet that length is 0.15-1mm forms by weaving, shaping. Described filter has super-elasticity and self-expanding characteristic.

Referring to Fig. 1 a and Fig. 1 b, the filter 100 of embodiment one includes main part 10 and is arranged at recovering hook 20 and the fixing anchor 30 of main part 10 one end.

Main part 10 has relative proximal part 101 and distal end 102, and it includes the proximal part drainage screen 11 near proximal part 101, the distal end drainage screen 12 near distal end 102 and is connected to the supporting section 13 between proximal part drainage screen 11 and distal end drainage screen 12. When, after filter 100 Spontaneous release in the blood vessel, supporting section 13 is for support blood vessels wall, and proximal part drainage screen 11 and distal end drainage screen 12 are used for filtering thrombosis. Proximal part drainage screen 11 is converged at proximal part 101 by a plurality of netting twine and forms space pyramidal structure. Distal end drainage screen 12 is converged at distal end 102 by a plurality of netting twine and forms space pyramidal structure.

Every netting twine can be linear type, or is shaped form, or part is straight line, and remainder is shaped form.

It is understood that the netting twine of the netting twine of proximal part drainage screen 11 and distal end drainage screen 12 can also be the combination of irregular curve or curve and straight line.

Refer to Fig. 1 c, the tapering of proximal part drainage screen 11 be filter 100 when Spontaneous release state, the projection on the cross section of vertical central axis with filter 100 of the outside dimension of the distal end of proximal part drainage screen 11 and proximal part drainage screen 11 is along the ratio of greatest length L1 of the vertical central axis of filter 100; The tapering of distal end drainage screen 12 is that filter 100 is when Spontaneous release state, the projection on the cross section of vertical central axis with filter 100 of the outside dimension of the proximal part of distal end drainage screen 12 and distal end drainage screen 12 is along the ratio of the greatest length L2 of the vertical central axis of filter 100, and the tapering of proximal part drainage screen 11 is less than the tapering of distal end drainage screen 12. Preferably, in the present embodiment, the outside dimension of the distal end of proximal part drainage screen 11 is equal to the outside dimension of the proximal part of distal end drainage screen 12, and is equal to the size H at the filter 100 largest outside diameter place on the longitudinal center's direction of principal axis being perpendicular to filter 100.

When filter 100 Spontaneous release, the proximal part drainage screen 11 projection on the cross section of vertical central axis with filter 100 along the greatest length L1 of the vertical central axis of filter 100 more than the distal end drainage screen 12 projection on the cross section of vertical central axis with the filter 100 greatest length L2 of vertical central axis along filter 100.

Longer near proximal part drainage screen 11 length of proximal part 101, blood flow after being entered main part 10 by distal end 102 high velocity stream can be played certain cushioning effect, make thrombosis enter proximal part drainage screen 11 in order, will not be formed eddy current cause greater impact power to cause proximal part drainage screen 11 filter 100 shifts. Meanwhile, longer proximal part drainage screen 11 can ensure that two strands of renal veinss return the painstaking effort stream thrombosis to resting on proximal part drainage screen 11 and produce sufficiently large area and wash away dissection enough for a long time, it is ensured that venacaval unobstructed for a long time.

Please refer to Fig. 1 d and 1e, proximal part drainage screen 11 includes a multiple connected Y type unit 110, and each Y type unit 110 all includes the first netting twine 111 and two article of second netting twine 112 extended to form by the first netting twine bifurcated at one end. A plurality of first netting twine 111 of multiple Y type unit 110 converges at proximal part 101 place, thus, when, after filter 100 Spontaneous release, proximal part drainage screen 11 has space pyramidal structure. Second netting twine of each Y type unit 110 is all connected with supporting section 13 away from the end of proximal part 101.

The intersection point of the second netting twine 112 of each Y type unit 110 and the distance of the intersection point A of the first netting twine 111 subpoint on the vertical central axis of filter 100 to proximal part 101 and corresponding second netting twine 112 and supporting section 13 subpoint on the vertical central axis of filter 100 ranges for 1:10 to 9:10 to the ratio of distances constant of proximal part 101. Specifically, in the present embodiment, this ratio is 1:2.

Every first netting twine 111 and the second netting twine 112 all can distinguish linearly type, it is possible to curved type, also can the curved type of part, remainder is type linearly. In the present embodiment, proximal part drainage screen 11 includes six length equal linear type the first netting twines 111 and equal linear type the second netting twine 112 of 12 length. The angle that often adjacent two the first netting twines 111 are formed at proximal part 101 place is equal.

Please continue to refer to Fig. 1 c, when filter 100 Spontaneous release, the first netting twine 111 in a Y type unit 110 and the junction point A of the second netting twine 112 are to the distance h of the vertical central axis of filter 100₁It is 1:10 to 7:16 with the ratio range of the size H at the filter 100 largest outside diameter place on the longitudinal center's direction of principal axis being perpendicular to filter 100. Specifically, in the present embodiment, this ratio is 1:4.

Please refer to Fig. 1 e and Fig. 1 f, often two article of first netting twine 111 of adjacent two Y type unit 110 and adjacent two article second netting twine 112 of corresponding two Y type unit 110 enclose one the first rhombus filter element 113 of formation. When described filter Spontaneous release, the ratio of the multiple first rhombus filter elements 113 of proximal part drainage screen 11 projected area S1 and the area S0 of the circle corresponding to the maximum outside diameter on longitudinal center's direction of principal axis of filter 100 on the cross section of vertical central axis being perpendicular to filter 100 ranges for 1:10 to 9:10. Specifically, in the present embodiment, this ratio is 5.5:10.

Due to the moderate dimensions of the first rhombus filter element 113, fully filtration can cause the thrombosis of pulmonary infarction, also be absent from due to all intercepted situation causing angiemphraxis of big microthrombus, it is ensured that vein unobstructed for a long time.

Please refer to Fig. 1 d and Fig. 1 g, distal end drainage screen 12 includes multiple the 2nd connected Y type unit 120. Each 2nd Y type unit 120 all includes the 3rd netting twine 121 and two article of the 4th netting twine 122 extended to form by the 3rd netting twine bifurcated at one end. A plurality of 3rd netting twine 121 of multiple 2nd Y type unit 120 converges at distal end 102 place. Thus, when, after filter 100 Spontaneous release, distal end drainage screen 12 has space pyramidal structure. 4th netting twine 122 of each 2nd Y type unit 120 is all connected with supporting section 13 away from the end of distal end 102.

Every the 3rd netting twine 121 and the 4th netting twine 122 all can distinguish linearly type, it is possible to curved type, also can the curved type of part, remainder is type linearly. In the present embodiment, distal end drainage screen 12 includes six articles of length equal linear type the 3rd netting twines 121 and equal linear type the 4th netting twine 122 of six articles of length. The angle that often adjacent two article of the 3rd netting twine 121 is formed at distal end 102 place is equal.

Please continue to refer to Fig. 1 c, when filter 100 Spontaneous release, the 3rd netting twine 121 in each 2nd Y type unit 120 and the junction point B of the 4th netting twine 122 are to the distance h of the vertical central axis of filter 100₂It is 1:10 to 7:16 with the ratio range of the size H at the filter 100 largest outside diameter place on the longitudinal center's direction of principal axis being perpendicular to filter 100. Specifically, in the present embodiment, this ratio is 1:8.

As can seen above, the main part 10 of filter 100 is on the whole in unsymmetric structure, the quantity of the Y type unit 110 in proximal part drainage screen 11 is the twice of the quantity of the 2nd Y type unit 120 in distal end drainage screen 12, and namely the cancellated density of proximal part drainage screen 11 is more than the cancellated density of distal end drainage screen 12.

Referring to Fig. 1 a and Fig. 1 b, supporting section 13 includes the equal straight-bar of six roots of sensation length 131. Every straight-bar 131 is substantially parallel to the vertical central axis of filter 100 and is distributed along the circumferencial direction uniform intervals of filter 100.

It is understood that straight-bar 131 can be directly connected to proximal part drainage screen 11 and distal end drainage screen 12, straight-bar 131 can also be connected by curved section with between proximal part drainage screen 11 and distal end drainage screen 12.

Every straight-bar 131 along the width of the circumferential direction of filter 100 more than arbitrary netting twine of proximal part drainage screen 11 and distal end drainage screen 12 along the width of the circumferential direction of filter 100.

In the present embodiment, every straight-bar 131 is 0.8 millimeter along the width of the circumferential direction of filter 100, and netting twine is 0.4 millimeter along the width of the circumferential direction of filter 100.

It is understood that in other embodiments, many straight-bars 131 can have one or more straight-bars to be replaced by shaped form bar, as long as the tapering of the proximal part drainage screen of filter is less than the tapering of distal end drainage screen. It will also be appreciated that, in other embodiments, many straight-bars 131 can there is at least one straight-bar be connected with proximal part drainage screen or distal end drainage screen by least one shaped form bar, as long as the tapering of the proximal part drainage screen of filter is less than the tapering of distal end drainage screen. It will also be appreciated that, in other embodiments, many straight-bars 131 can also there is a straight-bar omit not, now, a piece netting twine of proximal part drainage screen is directly joined directly together with a netting twine of telecentricity heart end drainage screen, as long as the tapering of the proximal part drainage screen of filter is less than the tapering of distal end drainage screen.

It is understood that in other embodiments, many straight-bars 131 and shaped form bar can be spaced apart in the circumferencial direction of filter.It will also be appreciated that, in other embodiments, straight-bar 131 and shaped form bar can not also be spaced apart in the circumferencial direction of filter, such as all straight-bar 131 can sequentially be distributed in the circumferencial direction of filter, whole shaped form bars can be followed straight-bar 131 continuation order and are distributed in the circumferencial direction of filter, and namely shaped form bar can arbitrarily be arranged between many straight-bars 131.

Should be appreciated that the structure of shaped form bar can include the wave-like line of one or more bending simultaneously. Referring to Fig. 2, in the present embodiment, recovering hook 20 is arranged at distal end 102 place of main part 10, utilizes the connection of recovering hook 20 and catching device (not shown) can be recycled to external from blood vessel by the filter 100 in implantable intravascular. Recovering hook 20 is the tubular structure with an opening. The opening direction of recovering hook 20 stretches out along the radial direction of filter 100 and offsets towards main part 10, and namely the angle β between opening direction and the vertical central axis of filter 100 of recovering hook 20 is less than 90 degree. The opening of recovering hook 20 the width D being perpendicular on opening direction more than or equal to recovering hook 20 tubular structure outside dimension d 1/5, thus retracting device can arrest recovering hook 20 easily. The opening of recovering hook 20 depth S on the longitudinal center's direction of principal axis being perpendicular to filter 100 less than or equal to recovering hook 20 tubular structure outside dimension d 19/20, thus after recovering hook 20 arrested by retracting device, recovering hook 20 can be drawn in recovery sheath pipe by retracting device. In the present embodiment, the opening of recovering hook 20 is 1mm in the width D being perpendicular on opening direction, and the opening of recovering hook 20 depth S on the longitudinal center's direction of principal axis being perpendicular to filter 100 is 1.5mm.

When the filter 100 of the present embodiment be subject in the blood vessel blood flow wash away at a high speed time, filter 100 may tilt. But owing to the tapering of the distal end drainage screen 12 near distal end 102 is more than the tapering of proximal part drainage screen 11 near proximal part 101, therefore when filter 100 occurs crooked, proximal part 101 can first contact blood vessel wall, it is to avoid the recovering hook 20 being positioned at distal end 102 place cannot arrest the risk of recovery because contact blood vessel wall. In addition, when the filter 100 of the present embodiment is when implanting human body, the filter 100 being in radial contraction state is discharged by sheath pipe, the radial direction support force of the proximal part drainage screen 11 of release is slightly smaller in advance, therefore rate of release is slow, when finding the proximal part drainage screen 11 of part release can be regained sheath pipe when off-position is not good, again discharges after adjusting sheath pipe position, and the proximal part drainage screen 11 of slow releasing also can be adjacent to blood vessel wall, it is ensured that the stability after filter 100 implantation.

Referring to Fig. 3, in the present embodiment, filter 100 also includes fixing anchor 30. Fixing anchor 30 is arranged at least one straight-bar 131 of supporting section 13, and and angle α between the straight-bar 131 being directly connected less than 90 degree. Fixing anchor 30 is in strip, and its one end is fixed on straight-bar 131, and the other end is free end and extends to the direction of proximal part 101. The vertical dimension of the straight-bar 131 that the free end of fixing anchor 30 is joined directly together to the fixing anchor 30 with its place is less than or equal to 3 millimeters. Thus, when filter 100 is after Ink vessel transfusing Spontaneous release, the straight-bar 131 of supporting section 13 supports blood vessel wall, and fixing anchor 30 thrusts blood vessel wall, provides reliable fixing for filter 100 further, it is prevented that filter 100 produces displacement in the blood vessel. It is understood that a straight-bar 131 can arrange two or more fixing anchor 30 according to actual needs.It is understood that when having shaped form bar inside supporting section 13, fixing anchor 30 can also be arranged on shaped form bar according to actual needs.

Referring to Fig. 4, the filter 100 of the present embodiment is subject to blood flow when washing away at a high speed in the blood vessel, and filter 100 may tilt. But owing to distal end drainage screen 12 tapering near distal end 102 is more than near proximal part drainage screen 11 tapering of proximal part 101, the radial direction support force of distal end drainage screen 12 is relatively big, it is beneficial to fixing anchor 30 and thrusts blood vessel wall away from the free end of distal end 102. When filter 100 be subject to blood flow wash away time, filter 100 will simply rotate around fixing anchor 30 small angle rotation, and does not shift, it is ensured that filter 100 implant after stability.

Filter 100 adopts delivery sheath percutaneous puncture femoral vein to implant in postcava, detects that filter 100 is after implanting postcava by X ray developing apparatus, it does not have produces, shift or upset. Filter 100 takes out after implanting 14 days, and the malaise symptoms such as stomachache does not occur in patient, and namely blood vessel is not caused damage when taking out by filter 100.

Embodiment two

Referring to Fig. 5 a, the structure of the filter 200 of the present embodiment is roughly the same with the structure of the filter 100 of embodiment one. Filter 200 includes main part 40 and is arranged at recovering hook 50 and the fixing anchor 60 of main part 40 one end. Main part 40 has relative proximal part 401 and distal end 402, and it includes the proximal part drainage screen 41 near proximal part 401, the distal end drainage screen 42 near distal end 402 and the supporting section 43 being connected between proximal part drainage screen 41 and distal end drainage screen 42. Filter 200 is distinguished by with filter 100: the structure of distal end drainage screen 42 is different from the structure of distal end drainage screen 12.

Please refer to Fig. 5 b, Fig. 5 c and and Fig. 5 d, the distal end drainage screen 42 of the present embodiment is distinctive in that with the distal end drainage screen 42 of first embodiment, distal end drainage screen 42 includes six articles of linear 5th netting twines 421, and six article of the 5th netting twine 421 converges at distal end 402 place near the end of distal end 402. Thus, when, after filter 200 Spontaneous release, distal end drainage screen 42 has space pyramidal structure. The angle that every the 5th netting twine 421 is formed at distal end 402 place is equal. The end away from distal end 402 of every the 5th netting twine 421 is all connected with proximal part drainage screen 41.

Every the 5th netting twine 421 can distinguish linearly type, it is possible to curved type, also can the curved type of part, remainder is type linearly.

Filter 200 adopts delivery sheath percutaneous puncture femoral vein to implant in postcava, detects that filter 200 is after implanting postcava by X ray developing apparatus, it does not have produces, shift or upset. Filter 200 takes out after implanting 14 days, and the malaise symptoms such as stomachache does not occur in patient, and namely blood vessel is not caused damage when taking out by filter 200.

It is understood that when the NiTi pipe cutting that the filter of the present invention adopts outside dimension to be d, sizing preparation, it is possible on same NiTi pipe, cutting forms a plurality of netting twine of proximal part drainage screen and distal end drainage screen and the straight-bar of supporting section. Every straight-bar along the circumferential direction of filter width less than NiTi pipe outside dimension d 1/2, and straight-bar along the width of the circumferential direction of filter more than width along the circumferential direction of filter of the curved section of composition proximal part drainage screen and the netting twine of distal end drainage screen and/or straightway.

When the NiTi pipe cutting that filter adopts outside dimension to be d, sizing form, recovering hook can be one-body molded with the main part of filter, and namely recovering hook can directly form at end cut one opening of NiTi pipe.When filter adopt titanium-nickel wire or NiTi bandlet by weaving, sizing form time, recovering hook can also be one have opening and NiTi pipe that outside dimension is d, and it can be connected as one by the mode welded with the proximal part of the main part of filter or distal end.

It is also understood that, recovering hook can also be arranged at the proximal part place of main part according to actual needs, as long as filter can be put in the pre-position of blood vessel by the conveyer device of conveying filter, and the retracting device reclaiming filter can connect recovering hook, and reclaimed by filter and exit blood vessel.

It is understood that the filter of the present invention can also adopt other elastic materials (such as, stainless steel silk, cobalt-chromium-nickel-molybdenum-ferroalloy, cobalt-chromium alloy or polymer) to make, it is also possible to formed by other suitable material any with self-expanding.

In sum, the filter of the present invention is implanted to human vas, and in the blood vessel after Spontaneous release, the tapering of the proximal part drainage screen of close filter proximal part is less than the tapering of the distal end drainage screen near filter distal end, and the radial direction support force of proximal part drainage screen is less than the radial direction support force of distal end drainage screen. Compared with prior art, the advantage of the filter of the present invention is: 1) when embolus is intercepted in proximal part drainage screen, the radial direction support force of proximal part drainage screen increases, reduce the gap between the radial direction support force of proximal part drainage screen and the radial direction support force of distal end drainage screen, reduce the possibility that filter is crooked, improve the efficiency of frit embolus, reduce the risk of postoperative sufferer thromboembolism again; 2) when recovering hook is located at the implanted human body of the filter at distal end place, the filter being in radial contraction state is discharged by sheath pipe, the radial direction support force of the proximal part drainage screen of release is slightly smaller in advance, therefore rate of release is slow, when finding the proximal part drainage screen of part release can be regained sheath pipe when off-position is not good, again discharge after adjusting sheath pipe position, and the proximal part drainage screen of slow releasing also can be adjacent to blood vessel wall, it is ensured that the stability after filter implantation; 3) the radial direction support force of distal end drainage screen is slightly larger, quickly can be ejected by sheath pipe during filter release, and fixing anchor can be subject to bigger bounce, and the dynamics that the free end of fixing anchor thrusts blood vessel is bigger, it is ensured that the stability after filter implantation; 4) proximal part drainage screen length is more than distal end drainage screen length, multiple thrombosis can be made to enter proximal part drainage screen in an orderly manner, avoid the generation that multiple thrombosis causes the situation of eddy current in proximal part drainage screen porch, also avoid eddy current and filter body is produced the generation of situation about impacting, reduce the possibility that filter is crooked; 5) proximal part drainage screen includes the rhombus filter element of multiple moderate dimensions, the rhombus filter element of multiple moderate dimensions can fully filter thrombosis, it also avoid due to the generation of all intercepted situation causing angiemphraxis of big microthrombus, it is ensured that vein unobstructed for a long time.

Comparative example one

The structure of the filter of comparative example one is roughly the same with the structure of the filter 100 of embodiment one, and it includes the proximal part drainage screen near proximal part, the distal end drainage screen near distal end and is connected to the supporting section between proximal part drainage screen and distal end drainage screen. It is distinguished by, when, after the filter Spontaneous release in the blood vessel of comparative example one, the tapering of proximal part drainage screen is more than the tapering of distal end drainage screen.

The filter of comparative example one adopts delivery sheath percutaneous puncture femoral vein to implant in postcava. Owing to the tapering of proximal part drainage screen is more than the tapering of distal end drainage screen, therefore the radial direction support force of proximal part drainage screen is more than the radial direction support force of distal end drainage screen. And after the implantation, proximal part drainage screen intercepts the embolus in lower blood, this gap is gradually increased, and ultimately results in filter crooked, have impact on the filter efficiency of filter; Further, owing to filter occurs crooked, cause that the position that the free end of the fixing anchor of part contacts with blood vessel wall is unstable, when breathing, due to the change of abdominal pressure, fixing anchor repeatedly thrusts and extracts blood vessel wall, causing that this position blood vessel is punctured, there are the malaise symptoms such as stomachache in patient. Developed equipment Inspection, there is abdominal part hematoma in patient, filter is taken out in advance, it does not have reaches intended therapeutic effect.

Referring to Fig. 6, developed equipment Inspection, the implantation position place before this filter inferior caval does not take out, inferior caval blood vessel wall is punctured rear blood outflow and forms hematoma.It follows that blood vessel is caused damage by the filter of this comparative example after the implantation.

Above in association with accompanying drawing, embodiments of the invention are described; but the invention is not limited in above-mentioned detailed description of the invention; above-mentioned detailed description of the invention is merely schematic; rather than it is restrictive; those of ordinary skill in the art is under the enlightenment of the present invention; without departing under present inventive concept and scope of the claimed protection situation, it may also be made that a lot of form, these belong within the protection of the present invention.

Claims

1. a filter, described filter includes the main part with relative proximal part and distal end, described main part includes between described proximal part and distal end and the proximal part drainage screen that is connected and distal end drainage screen, when described filter Spontaneous release, described proximal part drainage screen and distal end drainage screen are the space pyramidal structure that a plurality of netting twine is constituted, it is characterized in that, the tapering of described proximal part drainage screen is less than the tapering of described distal end drainage screen.

2. filter according to claim 1, it is characterized in that, described proximal part drainage screen includes a multiple connected Y type unit, each Y type unit all includes the first netting twine and two article of second netting twine extended to form by described first netting twine bifurcated at one end, described a plurality of first netting twine of multiple described Y type unit converges at described proximal part place, and described second netting twine of each described Y type unit is all connected with described distal end drainage screen away from the end of proximal part.

3. filter according to claim 2, it is characterized in that, when described filter Spontaneous release, described first netting twine in an arbitrary described Y type unit and the junction point of the second netting twine are 1:10 to 7:16 to the ratio range of distance and the size at described filter largest outside diameter place on the longitudinal center's direction of principal axis being perpendicular to described filter of the vertical central axis of described filter.

4. filter according to claim 2, it is characterized in that, often two articles of described first netting twines of adjacent two described Y type unit and adjacent two article second netting twine of corresponding two described Y type unit enclose, form a first rhombus filter element, when described filter Spontaneous release, the area ratio of the multiple described first rhombus filter element of described filter projected area on the cross section of vertical central axis being perpendicular to described filter and the circle corresponding to described filter maximum outside diameter on the longitudinal center's direction of principal axis being perpendicular to described filter ranges for 1:10 to 9:10.

5. filter according to claim 1, it is characterized in that, described distal end drainage screen includes multiple the 2nd connected Y type unit, each 2nd Y type unit all includes the 3rd netting twine and two article of the 4th netting twine extended to form by described 3rd netting twine bifurcated at one end, a plurality of 3rd netting twine of multiple described 2nd Y type unit converges at described distal end place, each 2nd Y type unit described 4th netting twine be all connected with described proximal part drainage screen away from the end of described distal end.

6. filter according to claim 5, it is characterized in that, when described filter Spontaneous release, described 3rd netting twine in arbitrary described 2nd Y type unit and the junction point of the 4th netting twine are 1:10 to 7:16 to the ratio range of the size at described filter largest outside diameter place on the longitudinal center's direction of principal axis being perpendicular to described filter after distance and the described filter Spontaneous release of the vertical central axis of described filter.

7. filter according to claim 1, it is characterized in that, described distal end drainage screen includes a plurality of linear 5th netting twine, described a plurality of 5th netting twine converges at described distal end place near the end of described distal end, and the end away from described distal end of every described 5th netting twine is all connected with described proximal part drainage screen.

8. filter according to claim 1, it is characterized in that, described main part also includes the supporting section being connected between described proximal part drainage screen and distal end drainage screen, and described supporting section includes many straight-bars, and described straight-bar is roughly parallel to the vertical central axis of described filter.

9. filter according to claim 8, it is characterised in that the quantity of described straight-bar is many, and the length of many described straight-bars is identical.

10. filter according to claim 8, it is characterised in that described straight-bar along the width of the circumferential direction of described filter more than arbitrary netting twine of described proximal part drainage screen and described distal end drainage screen along the width of the circumferential direction of described filter.

11. filter according to claim 8, it is characterised in that described supporting section also includes at least one shaped form bar, and one end of described shaped form bar is connected with described proximal part drainage screen, and the other end is connected with described distal end drainage screen.

12. filter according to claim 11, it is characterised in that described straight-bar and described shaped form bar are spaced apart in the circumferencial direction of described filter.

13. filter according to claim 11, it is characterised in that described straight-bar and described shaped form bar are not spaced apart in the circumferencial direction of described filter.

14. filter according to claim 8, it is characterized in that, at least one described straight-bar is provided with at least one fixing anchor for fixing described filter, and one end of described fixing anchor is fixed on described straight-bar, and the other end of described fixing anchor is free end and extends to the direction of described proximal part.

15. filter according to claim 14, it is characterised in that the angle between described fixing anchor and the described straight-bar being directly connected is less than 90 degree.

16. filter according to claim 14, it is characterised in that the vertical dimension of the described straight-bar that the free end of described fixing anchor is joined directly together to the described fixing anchor with its place is less than or equal to 3 millimeters.

17. filter according to claim 1, it is characterised in that described filter also includes recovering hook, described recovering hook is arranged at distal end or the proximal part of described main part; Described recovering hook is the tubular structure with an opening, and the opening direction of described recovering hook stretches out along the radial direction of described filter and offsets towards described main part; The opening of described recovering hook the width being perpendicular on described opening direction more than or equal to described recovering hook tubular structure outside dimension 1/5, the opening of the described recovering hook degree of depth on the longitudinal center's direction of principal axis being perpendicular to described filter less than or equal to described recovering hook tubular structure outside dimension 19/20.

18. filter according to claim 1, it is characterised in that the material of described filter is Nitinol, described filter forms the netting twine of described proximal part drainage screen and described distal end drainage screen by cutting on NiTi pipe, and carries out sizing and form.