Filter system

Abstract

This invention discloses a filter system, including a filter and a delivery device. The filter includes a radially outwardly extending filtration section and a support section connected to the filtration section. The filter has a first state and a second state. In the first state, the support section of the filter is constricted by a flexible connector. In the second state, the support section of the filter is open. The delivery device includes a limiting member, and at least one end of the flexible connector is fixed to the limiting member. The beneficial effects of this invention are: because the filter of this application includes a first state and a second state, in the first state the filter is partially constricted, increasing the stability and operability of the filter implantation. After the filter is implanted, it changes to the second state, which has a longer recovery period than the first state, thereby extending the recovery period of the filter while ensuring implantation stability.

Description

Technical Field

[0001] This invention relates to the field of interventional medical devices, and more particularly to a filter system. Background Technology

[0002] Pulmonary embolism is an acute condition with high morbidity and mortality. In the United States, there are 570,000 to 630,000 cases of symptomatic pulmonary embolism each year, of which 200,000 result in death. Although systemic anticoagulation therapy can achieve some efficacy, 3-20% of patients still experience recurrent pulmonary embolism. Moreover, anticoagulation therapy itself has a 26% complication rate, of which 5-12% are fatal. Some patients cannot tolerate anticoagulation therapy, such as those with acute bleeding, gastrointestinal ulcers, primary or metastatic tumors (especially intracranial tumors), pregnancy, or before surgical treatment.

[0003] In the history of preventing pulmonary embolism, humans have used methods such as heparin therapy and inferior vena cava ligation, but all of them have some obvious drawbacks. For example, 10-26% of patients undergoing heparin therapy experience pulmonary embolism again due to collateral circulation in the lower limbs and pelvis. In addition, venous ligation can hinder venous blood return to the heart and reduce cardiac output. Furthermore, 7-50% of patients experience pulmonary embolism again due to collateral circulation.

[0004] Starting in the early 1960s, various specialized inferior vena cava devices emerged to address these issues, such as inferior vena cava clips, but the complication rate was as high as 27%. Later, the development of interventional radiology provided a better solution, using minimally invasive non-surgical cannulation techniques to insert filters, significantly improving the effectiveness of clinical applications.

[0005] Filters can use their mesh structure to intercept or cut blood clots in veins, preventing fatal pulmonary embolisms. However, their duration of action in the body is limited by the recovery period. Currently, the main types of filters are open and closed. While open filters have a longer recovery period, they are less stable during implantation and prone to tilting. Closed filters, although more stable upon implantation, generally have a shorter recovery period due to their structure. A short recovery period limits treatment options for doctors and is detrimental to patient recovery; a tendency to tilt can lead to a series of complications and may also increase the difficulty of recovery.

[0006] Therefore, how to ensure a long recovery period for the filter while improving the controllability and stability of the filter's release pattern is a problem that needs to be optimized. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a filter system that addresses the above-mentioned deficiencies in the prior art.

[0008] The technical solution adopted by this invention to solve its technical problem is:

[0009] A filter system is provided, including a filter and a pushing device. The filter includes a radially outwardly extending filtration section and a support section connected to the filtration section. The filter includes a first state and a second state. In the first state, a portion of the support section of the filter is constricted by a flexible connector. In the second state, the support section of the filter is open. The pushing device includes a limiting member, and at least one end of the flexible connector is fixed to the limiting member.

[0010] In one embodiment, the filter further includes a flexible connector, and the end of the support section is provided with a first hole through which the flexible connector passes.

[0011] In one embodiment, one end of the flexible connector passes through a plurality of first holes and extends out of the body.

[0012] In one embodiment, the limiting member includes a receiving cavity, wherein, in the first state, the end of the support segment is at least partially located within the receiving cavity.

[0013] In one embodiment, one end of the flexible connector is fixed inside the receiving cavity, and the other end passes through a plurality of first holes and extends outside the body.

[0014] In one embodiment, the receiving cavity includes an electrode, and one end of the flexible connector is connected to the electrode.

[0015] In one embodiment, the receiving cavity includes a cutting device, one end of the flexible connector is fixed inside the receiving cavity, and the extension path of the flexible connector in the first state overlaps with the cutting path of the cutting device.

[0016] In one embodiment, the cutting device includes a blade disposed at the bottom of the receiving cavity, one end of the flexible connector is fixed to the bottom of the receiving cavity and covered by the blade, and the other end of the flexible connector is fixed to the side wall of the receiving cavity.

[0017] In one embodiment, the limiting member includes a push rod, and in the first state, one end of the flexible connector is fixed in the receiving cavity, and the other end is rotatably sleeved on the surface of the push rod.

[0018] In one embodiment, the limiting member further includes a sleeve rotatably connected to the push rod, with one end of the flexible connector fixed to the sleeve and the other end extending outside the body.

[0019] In summary, the filter system of the present invention has the following beneficial effects: Since the filter of the present application includes a first state and a second state, in the first state, the support section of the filter is constricted by the flexible connector, and in the second state, the support section of the filter is opened, the pushing device includes a limiting member, and at least one end of the flexible connector is fixed on the limiting member, which increases the stability and operability of the filter implantation. When the filter is implanted, it becomes the second state, which has a longer recovery period than the first state, thereby extending the recovery period of the filter while ensuring implantation stability. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0021] Figure 1 This is a schematic diagram of the structure of a filter provided by the present invention in its first state;

[0022] Figure 2 yes Figure 1 The diagram shown is a structural schematic of the filter in its second state.

[0023] Figure 3 This is a schematic diagram of the structure of another filter provided by the present invention in its first state;

[0024] Figure 4 yes Figure 3 The diagram shown is a structural schematic of the extended section of the filter in its first state.

[0025] Figure 5 This is a schematic diagram of the structure of another filter provided by the present invention in the second state;

[0026] Figure 6 This is a schematic diagram of the filter system provided by the present invention in its first state;

[0027] Figure 7 yes Figure 6 The diagram shows the structure of the extension section and housing of the filter system in the first state;

[0028] Figure 8 This is a schematic diagram of the extension section and receiving cavity of another filter system provided by the present invention in the first state;

[0029] Figure 9 This is a schematic diagram of the extension section and receiving cavity of another filter system provided by the present invention in the first state;

[0030] Figure 10 This is a schematic diagram of the extension section and receiving cavity of another filter system provided by the present invention in the first state;

[0031] Figure 11This is a schematic diagram of the structure of another filter system provided by the present invention in the first state;

[0032] Figure 12 yes Figure 11 The diagram shows the structure of the filter system sleeve in its first state.

[0033] Figure 13 This is a schematic diagram of the structure of another filter system provided by the present invention in the first state;

[0034] Figure 14 yes Figure 13 The diagram shows the structure of the first and second main bodies of the filter system in the first state. Detailed Implementation

[0035] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0038] In the field of filters, the end of a filter that is closer to the heart after it is implanted in the human body is called the proximal end, and the end that is farther from the heart is called the distal end.

[0039] See Figures 1 to 4 The filter 100 provided in one embodiment of the present invention includes a first state and a second state. Figure 1The diagram below shows the structure of the filter 100 provided by the present invention in its first state. In this state, the filter 100 includes a proximal end 110 and a filter section 111 extending radially outward from the proximal end 110. The filter section 111 includes a mesh rod structure, preferably a rhomboid distribution structure, thereby ensuring good filtration performance of the filter section 111. The end of the filter section 111 is connected to a support section 120, which is rod-shaped. The support section 120 continues to extend distally and connects to an extension section 133, which is also rod-shaped. The distal ends of the extension section 133 converge at the distal end 130. The filter 100 as a whole is spindle-shaped.

[0040] When the filter 100 is implanted into the human body in a spindle-shaped structure, the filter 100 has strong stability. The spindle-shaped structure not only has good support, but also helps the filter 100 to stay aligned during the implantation process, avoiding tipping or tilting.

[0041] After filter 100 is implanted in the human body, or after a period of time following implantation, filter 100 enters a second state, as described above. Figure 2 , Figure 2 This is a schematic diagram of the filter 100 in its second state. The distal ends of the extended sections 133 of the filter 100 are spaced apart, causing the distal ends of the filter 100 to open and form an umbrella shape. On the one hand, the contact area between the blood vessel wall and the filter 100 includes a portion of the extended section 133, thereby reducing the overall pressure of the filter 100 on the blood vessel wall and reducing the stimulation of the blood vessel wall by the filter 100, thus improving the recovery period of the filter 100. On the other hand, the open state also releases the tension of the closed state of the filter 100, thereby reducing the pressure. Furthermore, the open structure itself is also conducive to increasing the recovery period of the filter. In this embodiment, the extended section 133 in the second state can be regarded as part of the support section 120.

[0042] An anchor structure 121 is provided at the far end of the support section 120, and the anchor structure 121 serves as the boundary between the support section 120 and the extension section 133.

[0043] Preferably, in the second state, the distal end of the extension segment 133 extends radially outward or obliquely outward, thereby making the extension segment 133 more closely adhere to the blood vessel wall and preventing the free end of the extension segment 133 from pointing towards the inside of the blood vessel to enhance the filtration effect and generate thrombus.

[0044] Therefore, as the filter 100 transitions from the first state to the second state, the distal end 130 of the filter 100 in the first state opens, and the distal end of the extension 133 that was closed in the first state opens, thereby allowing the filter 100 to reach the second state.

[0045] Specifically, in the first state, the end of the extension segment 133 is bound by the suture 134; in the second state, the end of the extension segment 133 is unbound. In this embodiment, the suture 134 is a biodegradable material, including but not limited to polylactic acid (PLA), polyracemic lactic acid (PDLLA), polyglycolic acid (PGA), polylactic-co-glycolic acid copolymer (PLGA), polyhydroxyalkanoate (PHA), polydioxanone (PDO), polycaprolactone (PCL), etc. Considering the speed of endothelial cell overgrowth, it is preferable to set the biodegradable suture 134 to complete degradation in 8–12 days.

[0046] At the same time, the end of the extension segment 133 is provided with a ball head to avoid irritating the blood vessel wall. In addition, the design of the ball head also makes it easier for the end of the extension segment 133 to be converged and bound.

[0047] In some embodiments, a wire hole is provided at the end of the extension section 133, as shown in the figure. Figure 3-4 , Figure 3 This is a schematic diagram of another filter 100 in its first state. Figure 4 yes Figure 3 The structural diagram of the extension section 133 of the filter 100 in the first state shows that the wires 134 pass through the end of the extension section 133 one by one along the thread hole 135. The natural state of the extension section 133 is the open state. When the wires 134 pass through the end of the extension section 133 one by one along the thread hole 135, the ends of the extension section 133 will naturally move away from each other by a small distance, thereby avoiding tangling when the extension section 133 is open.

[0048] In some embodiments, the extension 133 may be a curved structure convex toward the blood vessel axis, such as... Figure 5 , Figure 5 This is a schematic diagram of the filter 100 in its second state. The bending initiation is located at the anchor, and the bending radius is no greater than 1 / 2 of the filter 100's diameter to prevent embolism caused by the filter 100's own structure. When the filter 100 reaches the second state, the extension 133 springs back to the blood vessel wall, and after springing back, it will have a smaller contact area with the blood vessel wall, which will further increase the filter 100's recovery period.

[0049] In another embodiment, see Figure 6-7 , Figure 6 This is a schematic diagram of another filter system in its first state. Figure 7 yes Figure 6The schematic diagram of the extension section and the receiving cavity of the filter system in the first state shows that the filament 134 is non-degradable, so specific means are needed to remove the restriction of the filament 134 on the extension section 133. The filament 134 is made of polymer or metal materials, such as nickel-titanium wire, stainless steel wire, nylon, fiber, etc. The filter 100 changes from the first state to the second state after the filter 100 is implanted and when the pusher 200 is removed.

[0050] Specifically, refer to Figure 7 The extension section 133 is bound to the storage part 211 of the pusher 200 by the silk thread 134. After the silk thread 134 passes through and fixes the extension section 133 in sequence, it extends to the outside of the body along the channel of the storage part 211. When the filter 100 is arranged in a reasonable position and without tilting, the operator pulls one end of the silk thread 134 from the outside, thereby untying the silk thread 134 and releasing the extension section 133.

[0051] In some embodiments, refer to Figure 8 , Figure 8 This is a schematic diagram of the extension section 133 and the receiving cavity 211 of another filter system in the first state. The state transition of the filter 100 can be completed by thermal melting to break the wire 134. The receiving cavity 211 is connected to the wire 222, the power connector 223 and the electrode 224. After the wire 134 is connected in series with the extension section 133, one end is fixed to the outside of the wire 222 and the other end is fixed to the electrode 224. When the filter 100 is arranged in a reasonable position and without tilting, the power is turned on or the radio frequency pulse is emitted, and the wire 134 embedded in the electrode 224 will melt and break, thereby realizing the release of the extension section 133.

[0052] In some embodiments, refer to Figure 9 , Figure 9 This is a schematic diagram of the extension section 133 and the receiving cavity 211 of another filter system in the first state. One end of the wire 134 is fixed inside the receiving cavity 211, preferably at the bottom, such as by fixing it to the nut 226. The other end of the wire 134 is passed through the extension section 133 and rotated and sleeved on the push rod 225. When the filter 100 is arranged in a reasonable position and without tilting, the push rod 225 is rotated, and the other end of the wire gradually unscrews from the push rod 225. At this time, whether it is directly pulled out of the receiving cavity 211 or the push rod 225 is continued to be rotated until it is completely removed, after the push rod 225 leaves the receiving cavity 211, one end of the wire 134 becomes a free end, while the other end remains fixed, thereby realizing the release of the extension section 133.

[0053] In some embodiments, refer to Figure 10 , Figure 10This is a schematic diagram of the extension section 133 and the receiving cavity 211 of another filter system in the first state. The bottom of the receiving cavity 211 is provided with a cutting structure 226. This embodiment includes multiple threads 134. One end of each thread 134 is fixed to the side wall of the receiving cavity 211, and the other end passes through the hole of a single extension section 133 and is fixed to the bottom of the receiving cavity 211. The cutting structure 226 covers the fixed end of the thread 134 at the bottom of the receiving cavity 211. In this way, when the cutting structure 226 rotates, it can cut the thread 134, thereby releasing the extension section 133. It is worth noting that the thread 134 is fixed to the side wall of the receiving cavity 211 and the other end is fixed to the bottom in order to prevent the thread 134 from entering the human body after the cutting structure cuts the thread 134.

[0054] The cutting structure 226 includes multiple spaced blades and is driven to rotate by the drive shaft 227.

[0055] As mentioned above, the first state of filter 100 is the initial release state, i.e., the semi-release state, and the second state of filter 100 is the final implantation state. It should be noted that the aforementioned embodiment is to implant filter 100 in a spindle shape to obtain stability during the release phase, and ultimately form an open structure to prolong the recovery period of filter 100. However, with a similar structure, filter 100 can be fully released and pressed against the blood vessel wall in the first state. After confirming that its implantation position is accurate, filter 100 reaches the second state and is fully released. For details, please refer to the following embodiment.

[0056] In one embodiment of the present invention, specifically, referring to... Figure 11 , Figure 11 This is a schematic diagram of the filter system in its first state. The support section 120 of the filter 100 has perforated structures 135. A wire 134 passes through multiple perforated structures 135 in the support section 120, with one end connected to the surface of a sleeve 229. The sleeve 229 is rotatably connected to the surface of a steel cable 230. The other end of the wire 134 extends outside the body. When the filter 100 is in its first state, if there is any tilt or unsatisfactory positioning, the support section 120 of the filter 100 can be pulled away from the blood vessel wall and retracted to the center of the blood vessel lumen by tightening the wire 134. Simultaneously, the filtering section 111 and the extension section 133 are moved away from the blood vessel wall. Then, the pusher 200 is rotated or advanced to adjust the shape and position of the filter 100. Once the filter 100 is properly positioned and without tilt, the wire 134 is removed from the body or cut short. Then, the steel cable 230 is unscrewed, and the remaining end of the wire 134 is withdrawn outside the body with the pusher, completing the implantation of the filter 100.

[0057] In some embodiments, refer to Figure 12 , Figure 12 yes Figure 11The schematic diagram of the sleeve 229 of the filter system shown in the first state shows that the sleeve 229 includes a channel 2291 through which the filament 134 extends to the outside.

[0058] In some embodiments, the filter 100 is a shuttle-shaped filter, and the pore structure 135 is disposed on the connecting rod of the shuttle-shaped filter.

[0059] In some embodiments, filter 100 is a dual-layer filter.

[0060] In yet another embodiment of the invention, reference is made to... Figure 13-14 , Figure 13 This is a schematic diagram of the first state of another filter system. Figure 14 yes Figure 13 The diagram shows the structure of the first and second main bodies of the filter system in the first state. The filter 300 is a combined filter, consisting of a first main body 310 and a second main body 320. The first main body 310 and the second main body 320 are arranged opposite to each other, and the support section 312 of the first main body 310 and the support section 322 of the second main body 320 are connected in the first state and separated in the second state. This allows for the simultaneous implantation of the combined filter 300, reducing surgical steps. At the same time, since the first main body 310 and the second main body 320 are implanted independently and do not affect each other, the overall recovery period of the filter is increased.

[0061] Specifically, the support section 312 of the first main body 310 has a hole structure 3121 at its end, and the support section 322 of the second main body 320 has a hole structure 3221 at its end. The inner diameter of the hole structure 3121 is larger than the outer diameter of the support section 322. After the support section 322 passes through the hole structure 3121, the wire 134 passes through the hole structures 3221 of multiple support sections 322 in sequence. In this configuration, the state changes of the first main body 310 and the second main body 320 can be controlled simultaneously by a single wire 134. One end is connected to the surface of the cannula 229, which is rotatably connected to the surface of the steel cable 230. The other end of the wire 134 extends outside the body. When the filter 100 is in the first state, if there is any tilt or unsatisfactory position, the support section 120 of the filter 100 can be pulled away from the blood vessel wall and retracted to the center of the blood vessel lumen by tightening the wire 134. At the same time, the filtering section 111 and the extension section 133 are moved away from the blood vessel wall simultaneously. Then, the pusher 200 is rotated or pushed to adjust the shape and position of the filter 300. When the filter 300 is positioned reasonably and without tilt, the wire 134 is removed from the body or the wire 134 is cut short. Then, the steel cable 230 is unscrewed, and the remaining end of the wire 134 is withdrawn outside the body with the pusher, completing the implantation of the filter 300.

[0062] After the thread 134 is removed, the first body 310 and the second body 320 detach from each other.

[0063] In another embodiment, the wire 134 passes sequentially through the hole structure 3221 of the plurality of support sections 322 and the hole structure 3121 of the support section 312.

[0064] In another embodiment, multiple threads 134 are used to sequentially pass through the hole structures 3221 of multiple support segments 322 and the hole structures 3121 of multiple support segments 312 to limit the first body 310 and the second body 320 respectively.

[0065] It should be noted that in these embodiments, biodegradable materials can be used for the filament 134 to achieve the same technical effect, which will not be elaborated here.

[0066] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A filter system comprising a filter, a feeding device, and a thread, characterized in that, The filter is for implantation into a blood vessel and includes a radially outwardly extending filter section and a support section connected to the filter section. The support section extends distally and is connected to an extension section. The end of the pushing device has a receiving cavity. The filament is a non-degradable polymer material or a metal material. The filter includes a first state and a second state. In the first state, the end of the extension section of the filter is at least partially bound by the filament in the receiving cavity. In the second state, the support section of the filter is open. The extension section is a curved structure convex to the axis of the blood vessel, and the bending radius of the curved structure is not greater than 1 / 2 of the diameter of the filter.

2. The filter system according to claim 1, characterized in that, The end of the extension section is provided with a thread hole, and one end of the thread passes through multiple thread holes in sequence and extends out of the body.

3. The filter system according to claim 1, characterized in that, The cavity is provided with an electrode and a wire electrically connected to the electrode. One end of the wire is fixed to the outside of the wire and the other end is fixed to the electrode after being connected in series with the extension section. The electrode is configured to melt the wire when energized.

4. The filter system according to claim 1, characterized in that, The receiving cavity is provided with a cutting structure. There are multiple threads. One end of each thread is fixed to the side wall of the receiving cavity, and the other end passes through the thread hole of a single extension section and is fixed to the bottom of the receiving cavity. The cutting structure covers the fixed end of the thread at the bottom of the receiving cavity.

5. The filter system according to claim 4, characterized in that, The cutting structure includes a blade located at the bottom of the receiving cavity, and the other end of the wire is fixed to the bottom of the receiving cavity and covered by the blade.

6. The filter system according to claim 1, characterized in that, It also includes a push rod that extends into the receiving cavity. In the first state, one end of the thread is fixed inside the receiving cavity, and the other end is rotatably sleeved on the surface of the push rod.

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