44 results about "Vena cava filters" patented technology

The invention relates to the technical field of medical instruments, and provides a vena cava filter capturing guide wire and device. And the stop block is arranged on the peripheral wall of the guide wire and is fixed relative to the guide wire. When the capturing guide wire is used, a transcervical passage and a transfemoral passage are firstly established, and then a catheter or an adjustable bent catheter is conveyed to a filter through the transfemoral passage; then a guide wire firstly penetrates through a central hole of the filter through a catheter, then the capture device is used for pulling the guide wire out of the jugular vein through the jugular vein channel until resistance is felt, at the moment, the stop block abuts against the central hole of the filter, and then a recovery sheath for capture is inserted into a blood vessel through the jugular vein through the guide wire; when the recovery sheath reaches the position of a recovery hook of the filter, the filter can be corrected by pulling the guide wire, if the recovery hook is adhered, the guide pipe can be pushed along the guide wire and the recovery hook, and the filter is recovered while the recovery hook is stripped. And when the filter completely enters the recovery sheath, the recovery sheath and the guide wire are withdrawn to complete the recovery of the filter.

The invention provides a limiting structure of an umbrella-shaped vena cava filter, the limiting structure is applied to a vena cava filter conveying system, the vena cava filter conveying system comprises a filter which is arranged in an inner cavity of an intervention sheath tube in a folded state, and a plurality of open grooves extending in the axial direction are formed in the limiting structure in the circumferential direction; the second supporting arm and the third supporting arm respectively form a second limiting part and a third limiting part which extend into the open groove along the first direction, and the second limiting part and the third limiting part abut against the side groove wall of the open groove along the two circumferential sides and are in circumferential limiting fit with the open groove; the second limiting part and the third limiting part abut against the inner wall of the intervention sheath tube through shape memory restoring force of the second limiting part and the third limiting part, and radial gaps exist between the second limiting part and the bottom groove wall of the open groove and between the third limiting part and the bottom groove wall of the open groove. The problem that in the prior art, the second supporting arm and the third supporting arm are prone to interference or scratching in the withdrawing or releasing stage is solved, precise unfolding and safe withdrawing of the filter are achieved, and the instrument loss and the vascular injury risk are reduced.

The utility model relates to the field of interventional therapy, and discloses a vena cava interventional valve. The vena cava interventional valve comprises a body support, the body support comprises an upper cone part, a barrel part and a lower cone part, and the upper cone part and the lower cone part are arranged at the two ends of the barrel part respectively; the fixing piece is arranged at the joint of the upper cone part and the barrel part; the covering film is arranged on the outer side of the body stent; and the artificial valve leaflet is arranged in the barrel part of the body bracket. The conveying size of an existing inferior vena cava filter is small and is only 6F, and the inferior vena cava filter is improved on the basis of the basic structure of the inferior vena cava filter, so that the inferior vena cava filter has the same small conveying size and fixing efficiency; by means of the fixing piece, positioning can be accurately and easily achieved in the valvular operation, and the pressing difficulty of the surgical operation is reduced; and the valve can be completely recovered before being completely released, so that the safety of the operation is improved.

The present application relates to the technical field of image analysis, and in particular to a kind of inferior vena cava filter implantation puncture target point auxiliary path planning method.Multiple CT images of the inferior vena cava of the patient are obtained, and the region to be distinguished is preliminarily divided based on the shape change of the blood vessel.Then, combined with the shape features and area change of the region to be distinguished, the blood vessel overlap representation evaluation index is determined, and the overlap and non-overlap regions are distinguished.Next, the overlap and non-overlap regions are combined, the shape similarity and overlap representation evaluation index similarity are analyzed, the smooth continuation index is determined, and the matching combination is screened out based on the index and the proportion of blood vessel overlap area.In addition, the gray value difference of blood vessels at different levels in the CT image is also considered, and the non-blood vessel overlap region is evaluated at different levels to more accurately represent the region belonging to the same blood vessel.Finally, according to the hierarchical evaluation result, the navigation path planning of the puncture target point in the region with blood vessel overlap is more accurate, and the planning accuracy is improved.

The invention discloses a recoverable woven filter and a taking-out device and system, relates to the technical field of interventional medical instruments, and aims to solve the problems that an existing vena cava filter depends on a center hook for grabbing, the taking-out difficulty is large, blood vessels are prone to being damaged, and the taking-out failure rate is high. The recoverable woven filter comprises a hooking piece, a protecting piece and a filtering part, the filtering part is woven by nickel-titanium metal wires to form a proximal section, a middle section and a telecentric section, the proximal section and the telecentric section are open grids with gradually-changed pore diameters, and an anchoring structure is arranged on the outer side of the middle section; the intersections of the metal wire weaving are in surface contact friction locking, and can be integrally contracted under axial traction force. The taking-out device comprises a tube base, a sheath tube and a grabbing mechanism, and the grabbing mechanism clamps any part of the filter through an occlusion head and pulls the filter into the sheath tube. The filter is high in softness, can be clamped and taken out at multiple parts, does not need to depend on a specific hooking piece, is low in alignment requirement, remarkably improves the taking-out success rate, and is suitable for vena cava thrombosis filtration and safe recovery.

The utility model discloses an inferior vena cava filter which comprises a recycling hook, a plurality of filtering ribs, a plurality of fixing thorns and a sheathing canal used for containing the filter, one ends of the filtering ribs are fixedly connected with the recycling hook, the fixing thorns are connected to the other ends of the filtering ribs, the filtering ribs are distributed in a bundle shape, and the filtering ribs are made of elastic memory materials. In a storage state, the filtering ribs are in a gathering state; in the natural state, the tail ends of the filtering ribs are bent downwards to form an arch shape, the outer side faces of the filtering ribs are concave faces, the inner side faces of the filtering ribs are convex faces, the fixing thorns are located on the outer side faces of the filtering ribs, in the natural state, the recycling hook is located in the center of the multiple filtering ribs, and the multiple fixing thorns face the same direction and extend in the direction away from the recycling hook. The thorn tips of the fixing thorns face upwards; when the filter is used, the recovery hook is always positioned in the middle of the plurality of filtering ribs, so that the contact between the recovery hook and the vein wall is effectively avoided, and the filter is convenient to take out.

The invention discloses a capturing device of an inferior vena cava filter and a using method, and relates to the technical field of medical instruments. According to the capturing device of the inferior vena cava filter and the using method, the capturing device comprises a leading-in device, a snare catheter is movably installed in the leading-in device, a snare is movably installed in the snare catheter, a traction hook is movably installed in the leading-in device, and torque devices are installed on the surface of one end of the snare catheter and the surface of one end of the traction hook. According to the inferior vena cava filter, the traction hook provided with the inverted-U-shaped hook is additionally arranged, so that the operation space and angle are not limited, the inferior vena cava filter can be taken out only through one puncture point without assistance of other instruments, and the inferior vena cava filter is easy and convenient to operate, minimally invasive and safe; the operation time is obviously shortened, and the radiation dose of doctors and patients is reduced.

The utility model relates to a recoverable inferior vena cava filter which comprises a recovery column and a vena cava filter body with an unfolded state and a folded state, a recovery hook is arranged on the recovery column, and the vena cava filter body comprises a plurality of first filter rods and a plurality of second filter rods; the first filter rod comprises a first sub-rod, a second sub-rod and a third sub-rod, the top end of the first sub-rod is connected with the recovery column, the tail end of the first sub-rod is connected with the top ends of the second sub-rod and the third sub-rod respectively, and first positioning hooks are arranged at the tail ends of the second sub-rod and the third sub-rod respectively; the top end of the second filter rod is connected with the recovery column, and the tail end of the second filter rod is provided with a second positioning hook. The problems that a traditional umbrella-shaped filter is low in capture rate, prone to deviation and poor in centering performance are solved, double-layer circumferential point contact is adopted to be fixedly attached to the blood vessel wall, good centering performance is guaranteed, and the problems that a traditional cylindrical supporting rod is large in contact area, intimal hyperplasia is likely to be caused, and the filter is difficult to recycle are solved.

The invention relates to the technical field of medical equipment, in particular to a convertible vena cava filter and a combination thereof. The convertible vena cava filter comprises a supporting device, a constraint line and a constraint piece, the restraint line is made of a non-degradable material, and the restraint piece is made of a degradable material so as to restrain the restraint line to form an annular structure; the supporting device comprises a plurality of supporting parts, one end of each supporting part can be limited by a constraint line to form a contraction structure, and the other end of each supporting part forms an expansion structure; and the constraint line is fixedly connected with the supporting part. According to the convertible vena cava filter provided by the invention, the restraint part provides a restraint effect for the restraint line, so that the supporting device is of an umbrella-shaped structure, after the restraint part is degraded and the restraint line loses efficacy, the supporting part is bounced off and is supported on a blood vessel wall, and the restraint line is fixed on the supporting part, so that the problem of pulmonary embolism caused by falling of the restraint line is avoided; the problem that an umbrella-shaped structure and a lantern-shaped structure are difficult to recycle is solved, and the advantages of the umbrella-shaped structure and the barrel-shaped structure are achieved at the same time.

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

The invention relates to a conveying device and a vena cava filter system, an outer sleeve is provided with an axially-through sleeve inner cavity, an inner core tube is provided with an axially-through core tube inner cavity, the inner core tube is movably arranged in the sleeve inner cavity of the outer sleeve in a penetrating mode, a release wire is movably arranged in the core tube inner cavity of the inner core tube in a penetrating mode, and the far end of the release wire is used for being connected with a filter. An axially-through inner cavity space is arranged in the centering positioning component, the centering positioning component is sleeved outside the inner core tube, the outer sleeve is connected with a first position of the centering positioning component, the inner core tube is connected with a second position of the centering positioning component, and the control device is connected with the outer sleeve and the inner core tube. The radial size of the centering positioning component is changed by controlling the axial relative displacement between the outer sleeve and the inner core tube. The centering positioning of the centering positioning part can ensure that the filter is always kept on the central axis of the blood vessel before being released as much as possible, and the neutral release state and the release state of the filter are ensured.

The present invention concerns a filter (1) for a blood vessel, and in particular a vena cava filter, comprising at least two anchoring branches (11) for anchoring the filter in the wall of the blood vessel, the anchoring branches having a fixed end (111) and a free end (112), the fixed ends of the anchoring branches being fixed to one another and the free ends being terminated with a hook (113) oriented toward the outside, characterised in that each of the anchoring branches comprises an anti-transfixion protection (114).

The invention relates to the technical field of medical instruments, and discloses a vena cava filter recovery system and method.The recovery system comprises a vena cava filter and a recovery device, and the recovery device comprises a guide device, a snare, a recovery sheath and a guide wire; the guide device comprises a connecting rod and a guide fixing claw, a central cavity capable of containing a guide wire is formed in the connecting rod, a recycling groove is formed in the outer side of one end of the connecting rod, the guide fixing claw is arranged at the end, close to the recycling groove, of the connecting rod, and the guide device is clamped with a filter rib rod of the vena cava filter through the guide fixing claw. The position of the vena cava filter is adjusted; the recovery sheath can contain the snare, the guide device and the vena cava filter, and a guide fixing claw of the guide device can penetrate through the recovery sheath to enter a blood vessel; the snare is used for capturing the filter recovery hook of the vena cava filter and recovering the vena cava filter into the recovery sheath. The guide device is additionally arranged to adjust the position of the vena cava filter in the blood vessel, and recycling is further facilitated.

The invention discloses a device for recycling an inferior vena cava filter, and relates to the field of devices for recycling the inferior vena cava filter.The device comprises a large sheath assembly, an expansion mechanism and an inner core assembly, the large sheath assembly is used for protecting the expansion mechanism and the inner core assembly, and the expansion assembly is used for recycling the inferior vena cava filter; the inner core assembly is used for positioning the whole device, the expansion mechanism is located in the large sheath assembly, and the inner core assembly is located in the expansion mechanism. According to the device for recycling the inferior vena cava filter, the flexible bending sleeve can be bent into a J shape through the first adjusting assembly, then the inclined inferior vena cava filter is centralized, recycling work of the inferior vena cava filter is facilitated, and the situation that the filter fails to be recycled due to inclination of the filter is avoided; and the filter can be recycled through the second adjusting assembly and the expansion assembly, so that the filter is more convenient to recycle.

The invention relates to the field of medical apparatus and instruments, and discloses a crossed and superposed vena cava filter screen, which comprises two crossed filter screens, and each filter screen comprises a connecting piece and more than three groups of interception units circumferentially fixed on the connecting piece at intervals; each intercepting unit comprises two arc-shaped structural rods, the connecting ends of the two arc-shaped structural rods are fixed to the connecting piece, the fixed ends of the two arc-shaped structural rods are fixed to each other, and anchoring structures extending outwards are arranged at the fixed ends. From the connecting end to the fixed end, the distance between the two arc-shaped structural rods is increased and then decreased; and the two arc-shaped structure rods of each group of interception units of one filter screen penetrate through the two adjacent groups of interception units of the other filter screen respectively. The device is long in window period, good in stability, easy to capture and recover and suitable for superior vena cava.

The invention relates to the technical field of image analysis, in particular to an auxiliary path planning method for implanting an inferior vena cava filter into a puncture target. A plurality of CT images of the inferior vena cava of a patient are obtained, and a to-be-distinguished area is preliminarily divided based on vascular morphological changes. And then, in combination with shape features and area change conditions of the to-be-distinguished region, determining a blood vessel overlapping characterization evaluation index, and distinguishing an overlapping region and a non-overlapping region. Thirdly, combining the overlapping area and the non-overlapping area, analyzing shape similarity and overlapping representation evaluation index similarity, determining a smooth continuation index, and screening out a matching combination based on the index and a blood vessel overlapping area proportion; besides, gray value differences of different levels of blood vessels in the CT image are also considered, and level evaluation is performed on a non-blood vessel overlapping region, so that the region belonging to the same blood vessel is represented more accurately. And finally, more accurate puncture target navigation path planning is carried out on the region with blood vessel overlapping according to a hierarchical evaluation result, so that the planning precision is improved.

The application discloses a woven type vena cava filter, which comprises a woven filter, and the woven filter is woven by a plurality of metal wires; the woven filter is sequentially formed with a fishing section, an abutting section and an opening section from a distal end to a proximal end; the metal wires of the abutting section are in a three-dimensional spiral shape, the three-dimensional spiral metal wires of the abutting section are overlapped and woven into a flat tubular structure, the abutting section is used for contacting with an inner wall of a blood vessel, so that the woven filter is fixed in the blood vessel; the metal wires of the fishing section are in a three-dimensional spiral shape, and the spiral radius of the three-dimensional spiral metal wires of the fishing section decreases in a distal end direction; the metal wires of the fishing section are formed with mesh holes, the mesh holes can allow blood flow and limit thrombus; the metal wires of the opening section are stranded into a plurality of metal bundles, and the metal bundles of the opening section are formed with openings, and the openings can allow the thrombus to pass. The application has better compliance and abutting property, can reduce damage to the blood vessel wall, prevents the filter from deviating, and has better developing effect.

An embolus filter introducer system has a symmetric introducer sheath with a filter inside. The introducer sheath can be attached at either end to a deployment actuator. The deployment actuator can thereby be used to push the filter out of the introducer sheath. Since the sheath can be oriented in a selectable direction, so can the filter, allowing the sheath to be introduced via a jugular or femoral approach to the vena cava.

The vena cava filter comprises a conveying pipe, a pushing pipe, a filter screen and an expander, a cover cap is arranged at the far end of the conveying pipe, an opening is formed in the cover cap, the pushing pipe is movably inserted into the conveying pipe relatively, the expander is movably inserted into the conveying pipe and the filter screen, and the filter screen has a containing state and a working state. When the filter screen is in a storage state, the filter screen is located in the conveying pipe and is folded into a pipe shape, when the filter screen is in a working state, the filter screen is located outside the far end of the conveying pipe and is self-expanded into a funnel shape, the pushing pipe is used for pushing the filter screen to enable the filter screen to extend out of the far end of the conveying pipe, and the cap is pushed by the filter screen to deform, so that the opening is enlarged. And the maximum inner diameter of the enlarged opening does not exceed the inner diameter of the conveying pipe. According to the utility model, the delivery tube, the pushing tube, the filter screen and the dilator are coaxial and integrated, so that the operation is more convenient, and the risk that the far end of the delivery tube shovels the blood vessel wall in the pushing process can be avoided.

The invention relates to a vena cava filter and a capturing and recycling device thereof, and relates to the field of interventional medical instruments.The vena cava filter comprises a filter screen and a recycling pipe, the recycling pipe is arranged at the end of the filter screen, a recycling pipe cavity is formed in the recycling pipe, a clamping hook groove is formed in the inner wall of the end of the recycling pipe cavity, and an elastic clamping hook is arranged in the clamping hook groove; one end of the elastic clamping hook is fixed in the clamping hook groove, the other end of the elastic clamping hook extends towards the filter screen, the end part of the elastic clamping hook extends into the recycling pipe cavity, and a recycling guide magnet spaced from the clamping hook groove is arranged in the recycling pipe cavity. The vena cava filter catching and recycling device comprises a recycling sleeve and a recycling guide wire, a catching head is arranged at one end of the recycling guide wire, the recycling guide wire penetrates through the recycling sleeve, the catching head comprises a catching guide magnet, the magnetism of the opposite ends of the catching guide magnet and the recycling guide magnet is opposite, and a clamping groove is formed in the side wall of the catching head; and the clamping groove and the clamping hook groove are correspondingly arranged, so that the recovery difficulty of the vena cava filter can be reduced.

A central release device of an inferior vena cava filter comprises a sheathing canal; a neck tube is arranged at the axis position of the filter, and the filter is compressed and contained in the sheath tube; the supporting piece is provided with supporting petals and a connecting part, the supporting petals are made of elastic materials, the supporting petals are arranged around the connecting part, and the connecting part is located at the axis position of the supporting piece; the supporting piece is compressed and contained in the sheath tube and located on the side, facing the opening of the sheath tube, of the filter. And the guide wire is arranged in the sheath tube and penetrates through the neck tube to be connected with the connecting part. After the supporting piece is released, due to the fact that the connecting part of the supporting piece is located at the axis position, the connecting part can be located at the central position of the vein after the supporting valve is opened and abuts against the vein. Therefore, when the filter is released, the neck tube can be located at the corresponding position of the connecting part along the guide wire, and then the neck tube is located at the central position of the vein. Therefore, the thrombus capturing efficiency of the filter can be improved, and the complication risk is reduced.

The application relates to a lower vena cava filter with a cutting structure and belongs to the technical field of medical devices. The lower vena cava filter comprises a recovery column, a recovery structure is arranged on the recovery column, a support mechanism comprises a plurality of support structures connected to the recovery column, the plurality of support structures are arranged at intervals in the circumferential direction of the recovery column, and a cutting structure is arranged on one side of each support structure in the direction of the axis of the recovery column. In the application, the cutting structure is arranged on the inner side of the support structure. In the process of recovering the lower vena cava filter, the cutting structure can cut the proliferative intima, the damage to the inner wall of the vein caused by irregular tearing of the proliferative intima when the lower vena cava filter is pulled is avoided, the incidence of complications of the lower vena cava filter is effectively reduced, and the time window for taking out the lower vena cava filter is prolonged to some extent, thereby prolonging the protection time of the patient.

The application relates to the technical field of medical devices, in particular to a vena cava filter taking-out device which comprises a traction tube, a first traction assembly and a second traction assembly; the first traction assembly comprises a first traction wire, a first guide ring and a first traction ring, one end of the first traction wire is connected to the first traction ring, and the other end of the first traction wire extends to the rear end of the traction tube through the first guide ring; the second traction assembly comprises a second traction wire, a second guide ring and a second traction ring; one end of the second traction wire is connected to the second traction ring, and the other end of the second traction wire extends to the rear end of the traction tube through the second guide ring. When the recovery hook enters the front end of the traction tube, the first traction ring and the second traction ring can be used to clamp the recovery hook at the same time. Therefore, when the traction tube is pulled outward, even if the longitudinal force is not enough, with the movement between the recovery hook and the traction ring, at least one traction ring will hook the recovery hook, so that the efficiency of recovery is ensured.

The application relates to a filter device for inferior vena cava, belonging to the technical field of medical instruments, and solves the problem that an inferior vena cava filter screen may be inclined and cannot be smoothly taken out of a blood vessel during implantation operation in the prior art. The application comprises a front positioning unit, a filter screen unit and a rear positioning unit, the filter screen unit is sleeved on the front positioning unit, and the rear positioning unit is sleeved on the filter screen unit; the front positioning unit and the rear positioning unit are both used for being unfolded first, and the unfolded positioning of the filter screen unit unfolded subsequently. The first positioning point of the front positioning unit and the second positioning point of the rear positioning unit are both on the center line of the front positioning sleeve, after the filter screen assembly is unfolded, the front positioning sleeve can ensure that the center line of the filter screen assembly coincides with the center line of the inferior vena cava blood vessel, the filter screen assembly cannot be inclined in the inferior vena cava blood vessel, and the filter screen assembly can be smoothly taken out of the inferior vena cava blood vessel subsequently.

The present invention relates to the technical field of implantable medical devices, and in particular to an intracavitary implant structure, and more particularly to a vena cava filter. Specifically disclosed are an intracavitary implant structure and a vena cava filter having the structure, comprising a central portion having a central axis and a functional portion having an outer periphery composed of a plurality of rods extending outward from the central portion. By improving the arrangement, structure and shape of the rods constituting the functional portion, the implant has better neutropenia and other effects.

The utility model discloses a vena cava filter which comprises a filter body and a plurality of supporting assemblies arranged outside the filter body and supported on a blood vessel wall, the supporting assemblies are arranged in the circumferential direction of the filter body at intervals, and each supporting assembly comprises a wall attaching piece attached to the blood vessel wall and a connecting piece connected between the filter body and the wall attaching piece. The connecting piece is made of a degradable metal material, the wall attaching piece is made of a degradable high polymer material, and the filter main body is made of a metal material; when the vena cava filter is arranged in a blood vessel, the filter main body is not in contact with blood in the blood vessel, and a spacing distance is formed between the outer contour surface of the filter main body and the blood vessel wall; the connecting piece is in direct contact with blood in a blood vessel, the filter main body and the connecting piece can be indirectly communicated with a positive electrode and a negative electrode of a power supply respectively, and when current passes through the connecting piece, the connecting piece can be electrolyzed to separate the filter main body from the connecting piece. The vena cava filter can be implanted into the blood vessel of a patient for a long time and cannot damage the blood vessel when taken out.

The application relates to a vena cava filter and a filter recovery system. The vena cava filter comprises a filter component for intercepting thrombus and a recovery component comprising a recovery seat, a recovery hook and a rotating assembly. The recovery seat is arranged at the proximal end of the filter component. The rotating assembly is connected to the end of the recovery hook and movably arranged in the recovery seat. The recovery hook is rotated relative to the recovery seat through the rotating assembly to adjust the position and / or orientation of the recovery hook relative to the filter component. The movable installation of the recovery hook into the recovery seat through the rotating assembly can realize the position and / or orientation adjustment of the recovery hook during hooking, facilitates the hooking recovery of the recovery hook from different angles, increases the adjustable performance of the recovery hook, adjusts the azimuth angle of the recovery hook, adjusts the recovery hook to a position far away from the blood vessel, reduces the recovery difficulty and facilitates the recovery operation.

The invention discloses a woven vena cava filter which comprises a woven filter body formed by weaving a plurality of metal wires. A fishing section, a wall adhering section and an opening section are sequentially formed in the woven filter from the far end to the near end; the metal wires of the adherent section are in a three-dimensional spiral shape, the three-dimensional spiral metal wires of the adherent section are overlapped and woven into a straight tubular structure, and the adherent section is used for being in contact with the inner wall of a blood vessel, so that the woven filter is fixed in the blood vessel; the metal wire of the fishing section is in a three-dimensional spiral shape, and the spiral radius of the three-dimensional spiral metal wire of the fishing section is gradually decreased in the far-end direction. Meshes are formed among the metal wires of the fishing section and can allow blood flow to pass through and limit thrombus to pass through; the metal wires of the opening section are stranded into a plurality of metal bundles, openings are formed among the metal bundles of the opening section, and thrombus can pass through the openings. The filter has better compliance and adherence, damage to the blood vessel wall can be reduced, the filter is prevented from deviating, and the developing effect is better.

The invention relates to the technical field of medical equipment, in particular to a convertible vena cava filter and a combination thereof. The convertible vena cava filter comprises a supporting device and a restraining ring. The supporting device comprises a plurality of supporting parts, one end of each supporting part can be limited by the restraint ring to form a contraction structure, and the other end of each supporting part forms an expansion structure; the restraint ring is made of a degradable material and comprises a plurality of limiting parts and a plurality of connecting parts, every two adjacent limiting parts are connected through the corresponding connecting part, and the limiting parts are fixed to the supporting part; the connecting part is made to be degraded prior to the limiting part. According to the convertible vena cava filter and the combination thereof, the connecting part is degraded prior to the limiting part, the supporting part is bounced off and supported on the blood vessel wall, the risk that degradable materials fall off is reduced, the problem that an umbrella-shaped structure and a lantern-shaped structure are difficult to recycle is solved, and the convertible vena cava filter and the combination thereof have the advantages of the umbrella-shaped structure and the barrel-shaped structure at the same time; and the problem of pulmonary embolism caused by falling of the degradable material is also avoided.

The invention discloses a method and a device for taking out an inferior vena cava filter, the device for taking out the inferior vena cava filter comprises a recovery sheathing canal and a looped catheter, the looped catheter comprises two catheter cavities which are symmetrically arranged, and the catheter cavities are provided with flexible bendable sections; firstly, the filter taking-out device is conveyed to the position above a filter to be taken out in a venous cavity, and the catheter cavity flexible bendable section is controlled to be bent in the preset direction; the two ends of the catheter cavity flexible bendable section penetrate into a filter screen structure of the filter, and the catheter cavity flexible bendable section is controlled to form an O-shaped closed loop; then entering a guide wire to form a loop, and exiting the loop forming catheter; the filter is separated from the vein cavity wall through cooperation of the looping guide wire and the recovery sheath tube, and the filter is taken out after being collected into the recovery sheath tube. The method and device are easy to operate, safe and reliable, the filter taking-out success rate is remarkably increased, the surgical operation time is shortened, and the method and device are particularly suitable for taking out difficult filters.