A controllable release intravenous filter

Abstract

The application discloses a controllable release vein filter, which comprises a filter body and a push rod, the filter body comprises an end pipe, filter rods and a movable unit, the end pipe is provided with a groove part at the end pipe, an annular limiting part and an annular limiting protrusion are fixed at the end pipe, the annular limiting part comprises an annular limiting seat, a circular ring block, a first annular connecting plate provided with a plurality of first through holes and a second annular connecting plate provided with a plurality of second through holes, the movable unit comprises a movable plate, a movable column and a plurality of elastic rods fixedly connected with the movable plate, one connecting rod is connected between two adjacent filter rods, a pressing rod is connected between each connecting rod and the movable column, the circular ring block and the movable plate are provided with a memory alloy unit, the memory alloy unit is in the form of a spring when in an austenitic phase, and the push rod comprises a rod body, an end circular ring rod and a plurality of connecting blocks for connecting the rod body and the end circular ring rod. The filter can realize controllable release.

Description

Technical Field

[0001] This application relates to the field of medical devices, specifically to a controllable release venous filter. Background Technology

[0002] Venous thromboembolism, especially deep vein thrombosis of the lower extremities and its most serious complication—pulmonary embolism—is a clinically fatal disease. For its treatment, placement of an inferior vena cava filter is a reliable approach.

[0003] The filter needs to be released and retrieved. The release steps include: 1) usually puncturing a vein in the groin or neck; 2) using a thin delivery sheath, delivering the compressed filter to the designated location in the inferior vena cava; 3) under X-ray guidance, the doctor releases the filter as if pressing a button, causing it to spring open from the sheath like an umbrella, with the hook gently securing it to the vessel wall to begin intercepting the thrombus. The retrieval steps include: 1) re-puncturing and inserting a retrieval sheath with a catcher, which is then placed over the retrieval hook at the top of the filter; 2) pushing the retrieval sheath forward, like retracting an umbrella into its case, detaching the filter's hook from the vessel wall and retracting the entire filter into the sheath; 3) withdrawing the entire sheath containing the filter from the vessel.

[0004] When releasing the filter, a push rod is usually used to push the filter out of the sheath. Since the filter unfolds after being pushed out of the sheath, a "bouncing" phenomenon sometimes occurs during release, which causes a certain difference between the released position and state of the filter and the desired position and state. At this time, the filter has been released, and the traditional push rod has detached from the filter, making it impossible to adjust the position of the filter. As a result, the insertion position and state of the filter are not ideal. Summary of the Invention

[0005] Purpose of the invention: This application aims to overcome the deficiencies of the prior art and provide a controllable release venous filter.

[0006] Technical Solution: A filter includes a filter body and a push rod. The filter body includes an end tube, multiple filter rods connected to the end tube, and a movable unit located within the end tube. The end tube has a groove, and an annular limiting part and an annular limiting protrusion are fixed to the end tube. The annular limiting part includes an annular limiting seat, a circular block, a first annular connecting plate with multiple first perforations, and a second annular connecting plate with multiple second perforations. Both the first and second annular connecting plates are connected to the annular limiting seat and the circular block. The movable unit includes a movable plate located between the annular limiting seat and the annular limiting protrusion, a movable column fixedly connected to the movable plate, and multiple elastic rods fixedly connected to the movable plate. A connecting rod connects two adjacent filter rods. Each connecting rod and movable column is connected by a retaining rod. A shape memory alloy unit exists between the annular block and the movable plate; the shape memory alloy unit is spring-shaped in the austenitic phase. The elastic rod, when without external force, comprises a straight rod, a first arc-shaped rod connected to the straight rod, and a second arc-shaped rod connected to the first arc-shaped rod. The push rod comprises a rod body, an end annular rod, and multiple connecting blocks for connecting rod bodies and end annular rods. The filter can be in a locked state and a released state. In the locked state, each elastic rod passes through a second through hole and a first through hole, and the end annular rod is located between the annular limiting seat and the first arc-shaped rod. In the released state, each elastic rod passes through a second through hole, and the second arc-shaped rod is located between the first annular connecting plate and the second annular connecting plate.

[0007] Furthermore, the groove is used for filter recovery.

[0008] Furthermore, one end of the shape memory alloy unit is connected to the annular block, and the other end is connected to the movable plate.

[0009] Furthermore, the number of elastic rods, first perforations, and second perforations is equal; multiple elastic rods are distributed in a ring with equal spacing; multiple first perforations are distributed in a ring with equal spacing; and multiple second perforations are distributed in a ring with equal spacing.

[0010] Furthermore, the number of the filter rod, connecting rod, and clamping rod is equal; the number of filter rods is between 6 and 8.

[0011] Furthermore, the end of the filter rod has barbs.

[0012] Furthermore, the shape memory alloy unit is made of nickel-titanium alloy; the elastic rod is made of cobalt-chromium alloy or stainless steel.

[0013] Furthermore, the cross-section of the end ring rod is semi-circular.

[0014] Furthermore, the movable plate is a circular plate, and the movable column is cylindrical.

[0015] Therefore, when the filter is in the released state, the first arc plate is basically straightened and cannot be bent due to the limiting effect of the inner circumference of the annular limiting seat on the elastic rod.

[0016] Furthermore, the thickness of the annular limiting seat is greater than the length of the first arc-shaped rod.

[0017] Therefore, when the filter is in the released state, the first arc plate is basically straightened and cannot be bent due to the limiting effect of the inner circumference of the annular limiting seat on the elastic rod.

[0018] Furthermore, the filter rod, connecting rod, and clamping rod are all made of shape memory alloy; the connecting rod and clamping rod are both curved when in the austenitic phase.

[0019] Beneficial effects: When the filter of this application is released, after the filter rod extends out of the sheath, the end tube can still remain locked with the push rod, so that the push rod keeps the filter under control, thereby allowing the filter to be adjusted and thus achieving controlled release of the filter.

[0020] In this application, after the filter is fully released, the active unit is limited by the shape memory alloy unit and the elastic rod, so that the clamping rod clamps the filter rod through the connecting rod, thus the filter remains expanded after implantation and its position is more stable. Attached Figure Description

[0021] Figure 1 A schematic diagram of the filter in its locked state;

[0022] Figure 2 for Figure 1 Enlarged view of region A in the middle;

[0023] Figure 3 A schematic diagram of the filter in its released state;

[0024] Figure 4 for Figure 3 Enlarged view of region B in the middle;

[0025] Figure 5 A schematic diagram showing the separation of the active unit from the end tube;

[0026] Figure 6 for Figure 5 Enlarged view of region C;

[0027] Figure 7 A schematic diagram of the filter cross-section in the locked state;

[0028] Figure 8 for Figure 7 Enlarged view of region D in the middle;

[0029] Figure 9 A schematic diagram of the filter cross-section in the released state;

[0030] Figure 10 for Figure 9 Enlarged view of region E in the middle;

[0031] Figure 11 A schematic diagram of the cross-section where the active unit separates from the end tube;

[0032] Figure 12 for Figure 11 Enlarged view of the F region. Detailed Implementation

[0033] Reference numerals: 1. End tube; 1.1 Groove; 1.2 Annular limiting protrusion; 1.3 Annular limiting seat; 1.4 Circular block; 1.5 First annular connecting plate; 1.5.1 First through hole; 1.6 Second annular connecting plate; 1.6.1 Second through hole;

[0034] 2.1 Filter rod; 2.2 Connecting rod; 2.3 Clamping rod;

[0035] 3.1 Movable plate; 3.2 Movable column; 3.3 Elastic rod; 3.3.1 Straight rod; 3.3.2 First arc-shaped rod; 3.3.3 Second arc-shaped rod; 3.4 Shape memory alloy unit;

[0036] 4.1 Rod body; 4.2 End ring rod; 4.3 Connecting block.

[0037] As shown in the figure, a controllable release intravenous filter includes a filter body and a push rod. The filter body includes an end tube 1, multiple filter rods 2.1 connected to the end tube 1, and a movable unit located inside the end tube 1. The end tube 1 has a groove 1.1, and an annular limiting part and an annular limiting protrusion 1.2 are fixed at the end tube 1. The annular limiting part includes an annular limiting seat 1.3, an annular block 1.4, a first annular connecting plate 1.5 with multiple first perforations 1.5.1, and a second perforation 1.5. The second annular connecting plate 1.6 of .6.1, the first annular connecting plate 1.5 and the second annular connecting plate 1.6 are both connected to the annular limiting seat 1.3 and the annular block 1.4, the movable unit includes a movable plate 3.1 located between the annular limiting seat 1.3 and the annular limiting protrusion 1.2, a movable column 3.2 fixedly connected to the movable plate 3.1, and a plurality of elastic rods 3.3 fixedly connected to the movable plate 3.2; a connecting rod 2.2 connects two adjacent filter rods 2.1, and each connecting rod 2.2 and the movable column 3.4 are connected to the movable column 3.5. Each of the moving columns 3.2 is connected to a retaining rod 2.3. A shape memory alloy unit 3.4 is located between the annular block 1.4 and the movable plate 3.1; the shape memory alloy unit 3.4 is spring-shaped in the austenitic phase. The elastic rod 3.3, when there is no external force, includes a straight rod 3.3.1, a first arc-shaped rod 3.3.2 connected to the straight rod 3.3.1, and a second arc-shaped rod 3.3.3 connected to the first arc-shaped rod 3.3.2. The push rod includes a rod body 4.1, an end annular rod 4.2, and multiple connecting rod bodies 4.1 and end... The filter is connected to the ring rod 4.2 via a connecting block 4.3. The filter can be in a locked state and a released state. In the locked state, each elastic rod 3.3 passes through a second through hole 1.6.1 and a first through hole 1.5.1, with the end ring rod 4.2 positioned between the annular limiting seat 1.3 and the first arc-shaped rod 3.3.2. In the released state, each elastic rod 3.3 passes through a second through hole 1.6.1, with the second arc-shaped rod 3.3.3 positioned between the first annular connecting plate 1.5 and the second annular connecting plate 1.6. As shown, the groove 1.1 makes the end tube 1 hook-shaped, thus allowing the groove 1.1 to be used for filter recovery. One end of the shape memory alloy unit 3.4 is connected to the annular block 1.4, and the other end is connected to the movable plate 3.1.

[0038] The number of elastic rods 3.3, first perforations 1.5.1, and second perforations 1.6.1 is equal; multiple elastic rods 3.3 are distributed in a ring with equal spacing; multiple first perforations 1.5.1 are distributed in a ring with equal spacing; multiple second perforations 1.6.1 are distributed in a ring with equal spacing. The number of filter rods 2.1, connecting rods 2.2, and clamping rods 2.3 is equal; the number of filter rods 2.1 is between 6 and 8. The ends of filter rods 2.1 have barbs. The shape memory alloy unit 3.4 is made of nickel-titanium alloy; the elastic rods 3.3 are made of cobalt-chromium alloy or stainless steel. The cross-section of the end ring rod 4.2 is semi-circular. The movable plate 3.1 is a circular plate, and the movable column 3.2 is cylindrical. The thickness of the annular limiting seat 1.3 is greater than the length of the first arc-shaped rod 3.3.2. The filter rod 2.1, connecting rod 2.2, and clamping rod 2.3 are all made of shape memory alloy; the connecting rod 2.2 and clamping rod 2.3 are both curved when in the austenitic phase.

[0039] As shown in the figure, the filter of this application can be in a locked state and a released state. Both the filter body and the push rod are inside the sheath. After the sheath reaches a designated position, the push rod pushes the filter body out. When the filter rod of the filter body extends out of the sheath, it can expand and harden. However, the end tube remains inside the sheath. At this time, due to the multiple elastic rods surrounding and limiting the end ring rod, the push rod's forward and backward movement can drive the end tube forward and backward, thus achieving controllable control of the filter body. When adjustment is needed, the position of the filter body can still be adjusted using the push rod.

[0040] When the filter body reaches the designated position and no adjustment is needed, the filter body can be completely pushed out of the sheath using the push rod. At this time, since the end tube is also located inside the blood vessel, under the influence of blood temperature, the shape memory alloy unit transforms into the austenitic phase, hardens, and becomes spring-like, causing the movable plate to move towards the annular limiting protrusion. Simultaneously, the elastic rod moves towards the annular limiting protrusion, so that the second arc-shaped rod is embedded between the first and second annular connecting plates (at this time, the first arc-shaped rod releases its enclosure and limiting effect on the end ring, allowing the end ring to detach from the filter as the push rod moves backward). Thus, not only does the shape memory alloy unit harden to support the movable plate, but the elastic rod, unable to bend due to the first arc-shaped rod being limited by the annular limiting seat, and the second arc-shaped rod embedded between the first and second annular connecting plates, achieves the limiting of the movable plate. In the released state, the relative position of the movable plate and the annular limiting seat is stable, causing the movable plate, along with the movable rod, to press against the abutment rod, which in turn presses against the connecting rod, resulting in better low-expansion of the filter rod, with its barbs inserting into the inner wall of the blood vessel for better anchoring.

[0041] Although the present invention has been illustrated and described with reference to preferred embodiments, those skilled in the art should understand that various changes and modifications can be made to the present invention without departing from the scope defined by the claims.

Claims

1. A controllable release venous filter, characterized in that, The filter includes a filter body and a push rod. The filter body includes an end tube, multiple filter rods connected to the end tube, and a movable unit located inside the end tube. The end tube has a groove, and an annular limiting part and an annular limiting protrusion are fixed to the end tube. The annular limiting part includes an annular limiting seat, a circular block, a first annular connecting plate with multiple first perforations, and a second annular connecting plate with multiple second perforations. Both the first and second annular connecting plates are connected to the annular limiting seat and the circular block. The movable unit includes a movable plate located between the annular limiting seat and the annular limiting protrusion, a movable column fixedly connected to the movable plate, and multiple elastic rods fixedly connected to the movable plate. A connecting rod connects two adjacent filter rods, and a clamping rod connects each connecting rod and the movable column. A shape memory alloy unit is located between the circular block and the movable plate. The elastic rod, when there is no external force, includes a straight rod, a first arc-shaped rod connected to the straight rod, and a second arc-shaped rod connected to the first arc-shaped rod; the push rod includes a rod body, an end ring rod, and a plurality of connecting blocks connecting the rod body and the end ring rod; the filter can be in a locked state and a released state. In the locked state, each elastic rod passes through a second perforation and a first perforation, and the end ring rod is located between the annular limiting seat and the first arc-shaped rod; in the released state, each elastic rod passes through a second perforation, and the second arc-shaped rod is located between the first annular connecting plate and the second annular connecting plate; under the action of blood temperature, the shape memory alloy unit becomes austenitic, hardens, and becomes spring-like, thereby causing the movable plate to move towards the annular limiting protrusion; and simultaneously, the elastic rod moves towards the annular limiting protrusion, thereby embedding the second arc-shaped rod between the first annular connecting plate and the second annular connecting plate.

2. The controllable release venous filter according to claim 1, characterized in that, The number of elastic rods, first perforations, and second perforations are equal; multiple elastic rods are distributed in a ring with equal spacing; multiple first perforations are distributed in a ring with equal spacing; and multiple second perforations are distributed in a ring with equal spacing.

3. The controllable release venous filter according to claim 1, characterized in that, The number of filter rods, connecting rods, and clamping rods is equal; the number of filter rods is between 6 and 8.

4. The controllable release venous filter according to claim 1, characterized in that, The filter rod has barbs at its end.

5. The controllable release venous filter according to claim 1, characterized in that, The shape memory alloy unit is made of nickel-titanium alloy; the elastic rod is made of cobalt-chromium alloy or stainless steel.

6. The controllable release venous filter according to claim 1, characterized in that, The cross-section of the end ring rod is semi-circular.

7. The controllable release venous filter according to claim 1, characterized in that, The movable plate is a circular plate, and the movable column is cylindrical; the thickness of the annular limiting seat is greater than the length of the first arc-shaped rod.

8. The controllable release venous filter according to claim 1, characterized in that, The filter rod, connecting rod, and clamping rod are all made of shape memory alloy; the connecting rod and clamping rod are both curved when in the austenitic phase.

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