Aspiration thrombectomy device

Abstract

The application discloses a suction and plug taking device, which comprises a negative pressure cavity main part including a hollow cylinder, a rotary suction mechanism including a suction piston, a threaded core rod and a threaded sleeve, the threaded core rod is provided with one-way asymmetric threads, the threaded sleeve comprises a nut sleeve, a pressure relief button and an unlocking yoke, the inner wall of the nut sleeve is provided with one-way threads, when the threaded core rod drives the suction piston to retreat, negative pressure can be formed in the hollow cylinder, the nut sleeve is provided with an open slit, the nut sleeve can be deformed in the radial direction, the unlocking yoke is arranged at the open slit and connected with the threaded sleeve, the unlocking yoke can be deformed under stress, the pressure relief button is connected with the unlocking yoke, pressing the pressure relief button can make the unlocking yoke deform, then the nut sleeve is opened in the radial direction, the one-way threads are disengaged from the one-way asymmetric threads, the one-key pressure relief is realized through cooperation of the nut sleeve, the pressure relief button and the unlocking yoke, the threaded self-locking can be quickly released, the threaded core rod can be reset, the operation is simple, and the operation time is saved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a device for aspirating thrombi. Background Technology

[0002] Acute ischemic stroke is one of the leading causes of disability and death worldwide, with large vessel occlusion stroke accounting for a significant proportion, requiring emergency endovascular intervention. Negative pressure aspiration is a crucial component of mechanical thrombectomy, using negative pressure suction to remove thrombi from blood vessels. It can be used alone or in conjunction with stent thrombectomy and has become a key technique in the treatment of acute ischemic stroke.

[0003] The core instruments of negative pressure aspiration technology include aspiration catheters and negative pressure aspiration devices. Currently, clinically used negative pressure aspiration devices mainly fall into three categories: dedicated thrombectomy aspiration pumps, general-purpose aspiration devices, and manual aspiration systems. Dedicated thrombectomy aspiration pumps are high-end devices specifically designed for mechanical thrombectomy in acute ischemic stroke, featuring precise negative pressure control, stable flow output, and an intelligent operating interface. Parameters can be adjusted according to the thrombus type and vascular conditions, avoiding pressure fluctuations from affecting the thrombectomy effect and simplifying complex procedures. General-purpose aspiration devices are typically negative pressure devices designed for other medical scenarios, but they are also used in clinical practice for thrombectomy in acute ischemic stroke. The main advantages of these devices are relatively low cost and easy availability, but they may not be as effective as dedicated devices in terms of negative pressure performance and ease of operation. Manual aspiration systems are the simplest and most economical negative pressure aspiration method, primarily using a large-capacity syringe (usually 50ml) to generate negative pressure manually.

[0004] Thrombectomy efficiency is the primary indicator for evaluating the performance of negative pressure aspiration devices, mainly measured by parameters such as first-attempt recanalization rate, operation time, and complete recanalization rate. Clinical studies show that different types of negative pressure aspiration devices exhibit significant differences in thrombectomy efficiency, with manual aspiration systems showing clear advantages in first-attempt recanalization rate and operation time. Therefore, despite its technical simplicity, manual aspiration systems remain important in clinical practice, especially in resource-constrained medical environments. However, manual aspiration systems have the following drawbacks: (1) Ordinary manual syringes require an additional locking device to maintain negative pressure. Over time, the negative pressure will slowly decrease, making it difficult to maintain a stable negative pressure for a long time, which leads to thrombus escape when withdrawing. (2) There are many joints, which makes it easy to leak air and lose negative pressure, and it is difficult to troubleshoot after the leak. (3) No pressure real-time display, operation requires intraoperative feel and experience, which is easy to misjudge; (4) Without anti-backflow design, blood / thrombus may flow back into the body after the traditional syringe is locked and removed, which may lead to infection and contamination. Summary of the Invention

[0005] To solve at least one of the above-mentioned technical problems, a suction device includes: The main components of the negative pressure chamber include a hollow cylinder; The rotary suction mechanism includes a suction piston that mates with the inner wall of the hollow cylinder, a threaded core rod connected to the suction piston, and a threaded sleeve disposed near the end of the hollow cylinder. The threaded core rod is provided with a one-way asymmetrical thread; The threaded sleeve includes a nut sleeve, a pressure relief button, and an unlocking fork. The inner wall of the nut sleeve is provided with the one-way thread. The one-way asymmetrical thread and the one-way thread cooperate to form a one-way transmission structure that only allows the threaded core rod to retract in a direction away from the far end of the hollow cylinder, and does not allow it to advance in a direction close to the far end of the hollow cylinder. When the threaded core rod drives the suction piston to retract, it can create a negative pressure in the hollow cylinder. The nut sleeve has an opening slot, and the nut sleeve can deform radially. The unlocking fork is located at the opening and connected to the threaded sleeve; the unlocking fork can deform under force. The pressure relief button is connected to the unlocking fork. Pressing the pressure relief button causes the unlocking fork to deform, thereby opening the nut sleeve radially and disengaging the one-way thread from the one-way asymmetrical thread.

[0006] In some embodiments, the opening extends axially, and the nut is fitted into the opening to form two opposing force-bearing ends; The unlocking fork includes a pressure-receiving part and paddles respectively disposed on both sides of the pressure-receiving part. The pressure-receiving part is at least partially exposed outward from the opening, and each paddle is connected to a corresponding force-receiving end. The pressure-receiving part is connected to the pressure relief button. Pressing the pressure relief button can cause the pressure-receiving part to deform, thereby causing the paddle to move to both sides, so that the two force-receiving ends move away from each other in the radial direction.

[0007] In some embodiments, a one-way check valve is provided inside the hollow cylinder. The one-way check valve is located near the far end of the hollow cylinder. When a negative pressure is formed inside the hollow cylinder, the one-way check valve can be opened. The one-way check valve is a duckbill-shaped check valve, and the duckbill-shaped check valve is integrally injection molded with the hollow cylinder. Alternatively, the one-way check valve may be a leaf-shaped check valve.

[0008] In some embodiments, a negative pressure gauge is also included, which is located at the far end of the hollow cylinder and is connected to the hollow cylinder to display the air pressure inside the hollow cylinder. The hollow cylinder has a branch pipe extending perpendicular to its axis at its distal end, and the branch pipe is integrally formed with the hollow cylinder. The negative pressure gauge is a Bourdon tube negative pressure gauge, and the pipeline of the Bourdon tube negative pressure gauge is seamlessly welded to the branch pipe.

[0009] In some embodiments, the unidirectional asymmetric thread is a unidirectional asymmetric sawtooth thread, an asymmetric rectangular thread, or a unidirectional ratchet thread; If the unidirectional asymmetric thread is a unidirectional asymmetric sawtooth thread, the tooth profile angle of the retracting force surface is 25°~35°, the tooth profile angle of the advancing force surface is 0°~10°, and the thread helix angle is 3°~8°. The thread helix angle is less than the friction angle of the advancing force surface and greater than the friction angle of the retracting force surface. If the unidirectional asymmetric thread is a unidirectional ratchet thread, the tooth profile angle of the retracting force surface is 45°~65°, the tooth profile angle of the advancing force surface is 0°~10°, and the thread helix angle is 3°~8°. The thread helix angle is less than the friction angle of the advancing force surface and greater than the friction angle of the retracting force surface.

[0010] In some embodiments, the distal end of the hollow cylinder is connected to a flexible hose, and a three-way valve is provided at the distal end of the flexible hose. The hollow cylinder, the flexible hose, and the three-way valve are integrally injection molded.

[0011] In some embodiments, the nut sleeve includes a connecting section and a threaded section arranged radially. The connecting section is fixedly connected to the hollow cylinder. The one-way thread is not provided on the inner wall of the connecting section, and the one-way thread is only provided on the inner wall of the threaded section. The axial length of the threaded section is greater than the axial length of the connecting section; The axial length of the connecting section does not exceed one-third of the total length of the nut sleeve.

[0012] In some embodiments, the force-receiving end is provided with a slot, the slot being a non-through blind slot with its opening formed on the end face of the force-receiving end, and at least a portion of the paddle being inserted into the slot from the opening. The paddle is provided with at least one limiting tooth, and the slot is provided with a groove that cooperates with the limiting tooth. The limiting tooth can be engaged in the groove to prevent the paddle from coming out of the slot.

[0013] In some embodiments, the suction piston includes a sealing region, a first connecting region, and a fixing region arranged sequentially along the distal end of the hollow cylinder toward its proximal end; The sealing area is provided with a single-ring or double-ring sealing boss. The outer diameter of the sealing boss is larger than the inner diameter of the hollow cylinder. The sealing boss is tightly fitted with the inner wall of the hollow cylinder, and the interference between the two is 0.05~0.1mm. The far end of the sealing area is provided with an arc-shaped or conical transition structure. The first connecting area is a cylindrical structure with an outer diameter smaller than that of the sealing boss. Multiple reinforcing ribs extending axially along the suction piston are provided on the outer side of the first connecting area. The multiple reinforcing ribs are evenly arranged circumferentially along the first connecting area. The fixing area has a concave groove, and the inner wall of the groove is provided with an elastic buckle for engaging with the distal end of the threaded core rod; the fixing area of ​​the suction piston is provided with a limiting component that cooperates with the distal end of the threaded sleeve to limit the maximum backward stroke of the threaded core rod.

[0014] In some embodiments, the threaded core rod includes a second connecting area, a threaded area, and an operating handle arranged sequentially along the direction from the distal end of the hollow cylinder toward its proximal end. The distal end of the second connecting area is provided with an engaging protrusion that engages with the elastic snap. The outer surface of the threaded area is provided with the unidirectional asymmetrical thread. The operating handle is located at the proximal end of the threaded area.

[0015] The beneficial effects of the present invention are: (1) The rotary suction mechanism of the present invention is equipped with an asymmetrical thread to achieve mechanical self-locking, which only allows backward movement and prohibits forward movement, with no rebound and no accidental push, and self-locking upon release, and the negative pressure does not decrease; (2) The hollow cylinder has a built-in one-way check valve and a self-locking thread to form a double safety barrier, preventing blood backflow and preventing pressure from gradually decreasing; (3) The hollow cylinder is integrated with a negative pressure gauge, which can display the negative pressure value in the pipeline in real time, guide the doctor's surgical operation, avoid ineffective aspiration and thrombus escape. By rotating the threaded core rod to increase the vacuum, combined with the real-time display of the negative pressure gauge, the operator can better control the negative pressure value and meet the aspiration of different types of thrombi. (4) One-click pressure relief is achieved by using the nut sleeve, pressure relief button and unlocking fork, which can quickly release the thread self-locking and reset the thread core rod. The operation is simple and saves surgical time. (5) The hollow cylinder, hose and three-way valve are integrally formed, reducing the number of pipeline interfaces and reducing the risk of air leakage. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the suction thrombus device according to Embodiment 1 of the present invention; Figure 2 The figures show a cross-sectional view, a front view, and a side view of the duckbill-shaped one-way check valve according to Embodiment 1 of the present invention. Figure 3This is a cross-sectional view of the rotary suction mechanism according to Embodiment 1 of the present invention; Figure 4 for Figure 3 Enlarged view of a portion of point A in the middle; Figure 5 This is a partially enlarged cross-sectional view of the unidirectional asymmetric thread of the threaded core rod according to Embodiment 1 of the present invention; Figure 6 This is an overall schematic diagram of the suction thrombus device according to Embodiment 2 of the present invention; Figure 7 This is an overall schematic diagram of the nut sleeve of the suction bolt device in Embodiment 2 of the present invention when it is spread open; Figure 8 This is a partially enlarged cross-sectional view of the unidirectional asymmetric thread of the threaded core rod according to Embodiment 2 of the present invention; Figure 9 This is a schematic diagram of the pressure relief button and the unlocking fork below it in Embodiment 2 of the present invention; Figure 10 This is a cross-sectional view of the nut sleeve in Embodiment 2 of the present invention during locking and opening. Figure 11 This is a schematic diagram of the suction thrombus device according to Embodiment 3 of the present invention. Figure 1 ; Figure 12 This is a schematic diagram of the suction thrombus device according to Embodiment 3 of the present invention. Figure 2 ; Figure 13 This is a schematic diagram of the suction plug device of Embodiment 3 of the present invention viewed along the axial direction. (a) shows the closed state of the blade-shaped one-way check valve, and (b) shows the open state of the blade-shaped one-way check valve. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0018] It should be noted that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0019] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0020] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] In the above description, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0022] For ease of explanation of the scheme in this application, the orientation of the device is defined as follows: The proximal end refers to the end that is closer to the surgeon when the device is used for the intended surgical application. The distal end refers to the end that is farther from the surgeon when the surgeon uses the device for the intended surgical application.

[0023] Example 1 like Figure 1 As shown in the figure, this embodiment discloses a thrombectomy device (hereinafter referred to as the device), which can be used for thrombectomy in acute ischemic stroke. The device includes a negative pressure chamber main body 1, a rotary suction mechanism 2, and a negative pressure gauge 3.

[0024] like Figure 1As shown, the main component 1 of the negative pressure chamber is manufactured using a one-piece injection molding process, including a hollow cylinder 11, a flexible hose 12, and a three-way valve 13. The hollow cylinder 11 is a thin-walled hollow cylindrical component, its internal space forming the core chamber (i.e., the negative pressure chamber) for generating and maintaining negative pressure. The main body of the hollow cylinder 11 is a standard cylindrical shape, while its distal end (the end furthest from the operator) is designed as an inverted conical structure. Along the proximal to distal direction, both the inner and outer diameters of the inverted conical structure gradually decrease, forming a tapered surface that facilitates the concentrated guidance and efficient discharge of fluid. The hollow cylinder 11 is made of a rigid, injection-moldable plastic material. Commonly used materials include, but are not limited to, one or more combinations of polyethylene (PE), polypropylene (PP), polystyrene (PS), and polycarbonate (PC). These materials not only possess good mechanical strength and dimensional stability but also meet the basic requirements of medical devices for biocompatibility and processing performance.

[0025] The distal end of the hollow cylinder 11 is directly connected to the flexible tube 12, which extends further to its distal end and integrates a three-way valve 13. It is important to note that the hollow cylinder 11, flexible tube 12, and three-way valve 13 are not assembled from parts, but rather formed in one piece using precision injection molding technology, ensuring the continuity and sealing of the entire fluid pathway. The flexible tube 12 is made of medical-grade thermoplastic elastomer (TPE), which combines the flexibility of rubber with the processability of plastic, exhibiting excellent resilience, resistance to bending fatigue, and biocompatibility, making it suitable for clinical scenarios involving repeated bending and long-term use. The three-way valve 13 is an adjustable T-shaped structure, allowing users to flexibly switch the flow direction according to actual operational needs, enabling both negative pressure suction and multi-purpose operations such as irrigation or contrast agent injection.

[0026] The integrated negative pressure chamber main component 1 is designed with full consideration of functionality and reliability in clinical use: its large internal volume can provide sufficient and stable negative pressure reserve for the aspiration process, effectively improving aspiration efficiency; at the same time, thanks to the integrated structure, it significantly reduces the number of connecting joints commonly found in traditional split structures, thereby greatly reducing the risk of air leakage due to loose interfaces or poor sealing during negative pressure aspiration, and improving the safety and ease of operation of the equipment.

[0027] like Figures 1 to 3As shown, a one-way check valve 4 is installed inside the hollow cylinder 11. The one-way check valve 4 is positioned near the distal end of the hollow cylinder 11, specifically at the position with the largest diameter in the inverted conical structure at the end of the hollow cylinder 11, to ensure optimal sealing and opening performance during fluid flow. In practical applications, the one-way check valve 4 preferably adopts a duckbill-shaped structure, which has advantages such as sensitive response, reliable sealing, and small opening pressure differential, making it particularly suitable for medical interventional devices. The one-way check valve 4 can be integrally molded with the hollow cylinder 11 using a single injection molding process, or it can be manufactured separately as a separate structure and then assembled into the designated position. Regarding material selection, the one-way check valve 4 can be made of various medical-grade elastic materials, including but not limited to thermoplastic elastomers (TPE), thermoplastic polyurethane (TPU), soft polypropylene plastics, and medical-grade silicone. Considering ease of processing, cost control, and biocompatibility, the preferred solution is to integrally mold the one-way check valve 4 made of thermoplastic elastomer and the hollow cylinder 11 made of polypropylene through injection molding, thereby improving the overall structural stability and sealing reliability. Of course, in certain specific applications, a separate structure can also be used, where the pre-prepared one-way check valve 4 is firmly fixed to a predetermined position inside the hollow cylinder 11 by means of bonding, ultrasonic welding, hot-melt welding, or mechanical clamping. The core function of the one-way check valve 4 lies in its one-way conduction characteristic: the valve will only open automatically when a negative pressure is formed inside the hollow cylinder 11 due to suction, allowing fluid (such as blood, gas, or thrombus) to flow smoothly into the hollow cylinder 11 from the distal end of the device; after the fluid enters the hollow cylinder 11, the suction operation stops, the internal negative pressure disappears or decreases, and the one-way check valve 4 will close quickly, effectively preventing the fluid from flowing back out of the hollow cylinder 11 to the distal end. This can significantly reduce the risk caused by misoperation or accidental pressurization, prevent captured thrombi from falling off again, or eliminate other forms of distal embolism events, thereby ensuring the safety and effectiveness of the interventional treatment process.

[0028] like Figure 1 and Figure 3As shown, the negative pressure gauge 3 is located at the far end of the hollow cylinder 11 and is directly connected to the interior of the hollow cylinder 11. Its main function is to monitor and display the air pressure state formed inside the hollow cylinder 11 in real time, especially the specific value of negative pressure (i.e., vacuum). The hollow cylinder 11 has a branch pipe 111 extending perpendicularly to its main axis at its far end. This branch pipe 111 is manufactured integrally with the hollow cylinder 11, thus ensuring the overall structural sealing and mechanical strength. The negative pressure gauge 3 is a Bourdon tube type negative pressure gauge, which has high accuracy and stability. Its connecting pipe is firmly fixed to the branch pipe 111 using seamless welding technology, which not only achieves a reliable sealed connection between the two but also effectively avoids measurement errors caused by loose connections or leaks. Through this integrated design, the negative pressure gauge 3 can continuously and accurately reflect the changes in vacuum inside the hollow cylinder 11, making the entire suction process visible and controllable. Users can judge the operating status of the device in a timely manner, effectively preventing operational errors or equipment abnormalities caused by pressure misjudgment, thereby improving safety and efficiency.

[0029] like Figure 1 and Figure 3 As shown, the rotary suction mechanism 2 includes a suction piston 21 that fits tightly with the inner wall of the hollow cylinder 11, a threaded core rod 22 that is fixedly connected to the suction piston 21, and a threaded sleeve 23 that is fixedly disposed near the end of the hollow cylinder 11.

[0030] like Figure 3 and Figure 4 As shown, the suction piston 21 is divided into three functional areas along the hollow cylinder 11 from the distal end to the proximal end: a sealing area 211, a first connecting area 212, and a fixing area 213. The sealing area 211, as the core sealing structure of the suction piston 21, has its outer surface tightly fitted to the inner wall of the hollow cylinder 11, effectively preventing gas or liquid leakage during suction. To enhance sealing performance, two double-ring sealing bosses 214 made of highly elastic silicone are provided on the outer circumferential surface of the sealing area 211. These two sealing bosses 214 are spaced apart along the axial direction, forming a double sealing guarantee. The outer diameter of each sealing boss 214 is slightly larger than the inner diameter of the hollow cylinder 11, and there is an interference fit of 0.05~0.1mm between them, with a preferred value of 0.08mm, thereby ensuring a good sealing contact state is maintained throughout the movement. Furthermore, the distal end of the sealing area 211 has an arc-shaped or conical transition structure, which not only helps to avoid scratching the inner wall surface of the hollow cylinder 11 during reciprocating motion, but also significantly reduces the fluid resistance during suction, effectively preventing blood / thrombus or other fluids from accumulating in the distal region of the suction piston 21.

[0031] like Figure 3 and Figure 4As shown, the middle part of the suction piston 21 is the first connecting area 212, which is used to transmit the pulling or pushing force from the threaded core rod 22, and at the same time improve the structural rigidity of the entire suction piston 21 to prevent collapse or deformation under negative pressure conditions. The first connecting area 212 is a cylindrical structure, and its outer diameter is smaller than that of the sealing boss 214. Therefore, it will not rub against the inner wall of the hollow cylinder 11 during movement, which reduces wear without affecting the sealing effect, while still providing sufficient structural support. To further enhance the resistance to deformation, multiple reinforcing ribs 215 are provided on the outer side of the first connecting area 212 along the axial direction. These reinforcing ribs 215 are evenly distributed circumferentially, which significantly improves the structural stability of the suction piston 21 under negative pressure environment and effectively prevents the suction piston 21 from being "flattened" due to suction negative pressure and losing its sealing function.

[0032] like Figure 3 and Figure 4 As shown, the fixing area 213 is located near the suction piston 21 and is used to reliably connect with the threaded core rod 22 and accurately transmit the movement of the threaded core rod 22. Specifically, the near end of the fixing area 213 is provided with a concave groove 216, and two elastic buckles 217 are symmetrically arranged on the inner wall of the groove 216. When the distal end of the threaded core rod 22 is inserted into the groove 216, the elastic buckles 217 will automatically spring back and lock the corresponding structure of the threaded core rod 22, achieving a quick and stable assembly connection. This connection method is not only easy to assemble, but also prevents relative slippage or loosening during subsequent pull-out operations, ensuring the reliability of the transmission. In addition, the fixing area 213 is also provided with a limiting component to limit the maximum stroke of the threaded core rod 22 backward (i.e., towards the near end). The limiting component is preferably an annular boss 218 disposed on the outer surface of the fixed area 213. When the threaded core rod 22 retracts to its limit position, the annular boss 218 abuts against the distal end face of the threaded sleeve 23, thereby preventing the threaded core rod 22 from retracting further. This design effectively avoids the sealing area 211 from colliding with the threaded sleeve 23 due to excessive retraction, protects the fragile sealing boss 214 from damage, and also prevents seal failure or sudden pressure relief due to excessive retraction of the suction piston 21, ensuring the safety and stability of equipment operation.

[0033] like Figure 3 and Figure 4As shown, the fixing area 213 and the first connecting area 212 are typically manufactured using an integral injection molding process to ensure the integrity of the structure and the strength of the connection. These two areas can be made of engineering plastic materials with moderate rigidity and easy injection molding, such as polypropylene (PP), polycarbonate (PC), or polyamide (PA). The sealing boss 214, however, needs to be made of a material with good elasticity and excellent sealing performance, such as medical-grade silicone, thermoplastic elastomer (TPE), or elastic polyurethane (TPU). To facilitate manufacturing and improve the reliability of the connection between components, a sealing material with good compatibility with the first connecting area 212 and the fixing area 213 is preferably selected, thereby achieving integral injection molding of the sealing area 211 with the rest of the parts. Of course, in certain specific applications, a split structure can also be used, for example, by using a slot and protrusion structure to engage the first connecting area 212 and the sealing area 211 to meet different assembly or maintenance needs.

[0034] like Figures 3 to 5 As shown, the threaded core rod 22 has three functional areas arranged sequentially from the far end to the near end along the hollow cylinder 11: a second connecting area 221, a threaded area 222, and an operating handle 223. The second connecting area 221 is located at the farthest end, and its end is provided with a locking protrusion 224 specifically designed for a secure engagement with the elastic latch 217. This locking protrusion 224 can tightly engage with the elastic latch 217 on the suction piston 21, thereby ensuring a reliable fixed connection between the threaded core rod 22 and the suction piston 21, preventing loosening or displacement during negative pressure operation. The outer surface of the threaded area 222 is provided with a unidirectional asymmetrical thread 225. The key to this thread structure lies in the fact that its two opposing force-bearing surfaces (i.e., the forward force-bearing surface and the backward force-bearing surface) employ different tooth profile angles and surface friction coefficients, thus achieving significant differences in mechanical properties. The mechanism ensures that the forward force meets the mechanical self-locking condition, preventing further advancement; conversely, the reverse force does not meet the self-locking condition, allowing free retraction in the reverse direction, forming a unidirectional self-locking threaded mechanism that only retracts and cannot advance, thus maintaining stable negative pressure. During forward rotation (e.g., clockwise rotation of the threaded core rod 22), the thread helix angle is less than the friction angle of the forward force-bearing surface, preventing the threaded core rod 22 from advancing and achieving the self-locking function. During reverse rotation (e.g., counterclockwise rotation of the threaded core rod 22), the thread helix angle is greater than the friction angle of the backward force-bearing surface, allowing the threaded core rod 22 to retract, and it can also retract again at any time to increase the vacuum level. (Thread helix angle) The inclination angle of the thread line relative to the axis of the threaded mandrel 22 is called the thread helix angle. ,in, This refers to the lead of the thread. The mean diameter of the threaded mandrel 22; friction angle It is the equivalent angle generated by sliding friction. ,in is the coefficient of friction.

[0035] Optionally, the unidirectional asymmetric thread 225 includes unidirectional asymmetric sawtooth threads, asymmetric rectangular threads, and unidirectional ratchet threads. This embodiment preferably uses a unidirectional asymmetric sawtooth thread, and the tooth angle of the retraction force-bearing surface 225a of the unidirectional asymmetric sawtooth thread is... The angle is 25° to 35°. The angle between the retracting force-bearing surface 225a and the surface perpendicular to the axis of the threaded core rod 22 is the tooth profile angle of the advancing force-bearing surface 225b. The range is 0° to 10°. The helix angle is the angle between the forward force-bearing surface 225b and the surface perpendicular to the axis of the threaded core rod 22, and is 3°~8°. The surface of the backward force-bearing surface can be polished to reduce its friction coefficient. ≤0.09, the friction angle of the retracting force-bearing surface is calculated. The forward force-bearing surface can be roughened to reduce its friction coefficient. The friction angle of the forward-moving force-bearing surface is calculated. thread helix angle The value of satisfies .

[0036] More preferably, the tooth angle of the retractable force-bearing surface 225a Designed with a 28° angle, and a 225b tooth profile angle on the forward force-bearing surface. The design angle is 5°, the thread helix angle is designed to be 6°, and the friction angle of the retraction force-bearing surface is... The friction angle of the forward-applying surface is 5°. With a rotation angle of 14°, it fully meets the mechanical requirements of unidirectional self-locking, ensuring stable locking under negative pressure and allowing users to flexibly adjust the vacuum level through simple reverse rotation.

[0037] like Figure 3 As shown, the operating handle 223 is located near the threaded area 222. Its structure can be varied according to actual usage needs, including a one-piece molded plastic structure, a foldable structure, or a grip structure with anti-slip texture, etc., designed to adapt to the one-handed operation habit unique to the "reverse-only" threaded mechanism. In this embodiment, a T-shaped anti-slip grip structure is preferred because it is not only ergonomic and easy to apply force, but also effectively prevents slippage during operation. In addition, the surface of the operating handle 223 is provided with fine anti-slip texture or particle structure to enhance grip stability; both ends are rounded to avoid sharp edges causing scratches or damage to the user's skin or other parts of the equipment during use or assembly, improving overall safety and comfort.

[0038] In terms of material selection, the threaded core rod 22 is manufactured entirely from medical-grade polypropylene (PP) or thermoplastic elastomer (TPE) using a two-material integrated injection molding process. The main structure is made of rigid medical-grade polypropylene, ensuring sufficient structural strength and dimensional stability; while the thermoplastic elastomer precisely covers the surface area of ​​the T-shaped anti-slip operating handle 223, providing a soft touch and excellent anti-slip performance, balancing functionality and user experience. This composite material solution not only meets the stringent requirements of medical devices for biocompatibility and sterilization adaptability but also achieves a harmonious balance between structural strength and operational comfort.

[0039] like Figure 1 and Figure 3 As shown, a threaded sleeve 23 is positioned near the end of the hollow cylinder 11. The threaded sleeve 23 has a through hole (not shown in the figure) extending axially along the hollow cylinder 11, providing an insertion channel for the threaded core rod 22. The threaded core rod 22 is inserted from the outside through this through hole and extends into the interior space of the hollow cylinder 11. The inner wall of the through hole has a unidirectional thread structure that matches the unidirectional asymmetrical thread 225 on the outer surface of the threaded core rod 22. This threaded engagement is not a typical symmetrical thread connection, but a specially designed unidirectional transmission mechanism: when the threaded core rod 22 is subjected to a force in a specific direction, the unidirectional asymmetrical thread 225 meshes with the unidirectional thread on the inner wall of the through hole, allowing the threaded core rod 22 to move backward only in a direction away from the far end of the hollow cylinder 11; if an attempt is made to push or rotate the threaded core rod 22 towards the far end of the hollow cylinder 11, due to the asymmetry of the thread geometry, a self-locking mechanism is generated between them, effectively preventing relative movement in that direction. Therefore, this structure forms a reliable unidirectional transmission mechanism, ensuring directional control and negative pressure stability during use. The threaded sleeve 23 can be made of biocompatible medical-grade plastic materials, such as polypropylene (PP), to meet the hygiene and safety requirements of medical applications. In terms of manufacturing process, the threaded sleeve 23 can be integrally manufactured with the hollow cylinder 11 through injection molding to improve structural integrity and sealing; alternatively, it can be a separate structure, subsequently firmly fixed to the proximal end of the hollow cylinder 11 through bonding, ultrasonic welding, hot-melt welding, or mechanical clamping. Furthermore, to enhance the structural stability and deformation resistance of the threaded sleeve 23 under stress, two symmetrical side wings 231 are provided on its outer surface. These two side wings 231 have a trapezoidal plate structure, which not only helps to enhance local stiffness but also provides better gripping or positioning assistance during assembly or operation, thereby effectively improving the overall dimensional stability and reliability of the threaded sleeve 23.

[0040] The working process of the thrombectomy device disclosed in this embodiment is as follows: When the operator prepares to perform the thrombectomy, he / she first firmly grasps the operating handle 223 located near the proximal end of the threaded core rod 22 and slowly and smoothly rotates the operating handle 223 counterclockwise. During this process, the rotational force applied to the operating handle 223 is transmitted through the threaded core rod 22 to the unidirectional asymmetric thread 225 on its outer periphery, specifically acting on the retraction force-bearing surface of the unidirectional asymmetric thread 225. Since the thread helix angle corresponding to this direction (i.e., the counterclockwise retraction direction) is greater than the friction angle in this direction, the basic condition of mechanical self-locking is not met, allowing the threaded core rod 22 to smoothly and without jamming retract inside the hollow cylinder 11. As the threaded core rod 22 moves backward, the suction piston 21, which is rigidly connected to its front end, also moves backward in sync, thereby gradually increasing the volume of the negative pressure cavity formed inside the hollow cylinder 11. As the cavity volume continues to expand, the gas inside the cavity is diluted, and the internal pressure is significantly reduced, forming a stable negative pressure environment.

[0041] When the negative pressure in the negative pressure chamber accumulates and reaches a preset threshold, the duckbill-shaped one-way check valve 4 located at the connection between the tubing 12 and the negative pressure chamber will deform under the action of the pressure difference on both sides—its duckbill part will open inward under the action of the pressure difference, and the negative pressure in the negative pressure chamber will be transmitted to the distal end of the catheter through the tubing 12. The thrombus or blood on the blood vessel side can then be smoothly drawn into the negative pressure chamber under the drive of negative pressure, realizing the effective thrombus aspiration function. At the same time, the negative pressure gauge 3 set on the hollow cylinder 11 of the device will measure the pressure change in the chamber in real time. Its pointer deflects synchronously with the increase of the negative pressure value. The operator can observe the reading of the pointer to accurately determine whether the current negative pressure has reached the expected target value.

[0042] When the reading displayed on the negative pressure gauge 3 reaches the ideal negative pressure level set by the operator, the operator immediately stops rotating the operating handle 223 and releases the handle. At this time, the continuous negative pressure in the negative pressure chamber applies an axial force to the suction piston 21 pointing distally (i.e., toward the catheter). This force is transmitted through the suction piston 21 to the threaded core rod 22 and ultimately acts on the forward force-bearing surface of the unidirectional asymmetric thread 225. It is worth noting that in the forward direction (i.e., the clockwise advancing direction), the thread helix angle is smaller than the friction angle in that direction, fully satisfying the mechanical self-locking condition of the thread. Therefore, even with the thrust from the negative pressure chamber, the threaded core rod 22 cannot move forward, the suction piston 21 is firmly locked in its current position, and the volume of the negative pressure chamber remains constant, ensuring a long-term stable maintenance of the negative pressure state.

[0043] After the aspiration action is completed, as the pressure difference between the negative pressure chamber and the blood vessel side gradually decreases or even tends to balance, the duckbill-shaped one-way check valve 4 will automatically close due to the elastic recovery ability of its own material. The two flexible lips of the duckbill are tightly attached to form a reliable sealing interface, which effectively prevents the backflow of blood / thrombus, prevents accidental push / accidental pressure, avoids air embolism, thrombus dislodgement or distal embolism, and forms a dual negative pressure maintenance mechanism of "threaded self-locking + one-way valve".

[0044] If the negative pressure value displayed by gauge 3 after the initial aspiration does not reach the surgeon's expected target, the surgeon can immediately perform an incremental adjustment: grip the operating handle 223 again and continue rotating it counterclockwise, causing the threaded core rod 22 to retract further, thereby expanding the volume of the negative pressure chamber and increasing the negative pressure value within the chamber. Once the new target value indicated by gauge 3 is achieved, the surgeon releases the handle again, and the threaded self-locking mechanism immediately activates, quickly locking the current negative pressure state and ensuring the increased negative pressure is stably maintained. This incremental adjustment process can be flexibly and repeatedly performed multiple times according to the actual situation during the procedure until the ideal aspiration negative pressure value is finally obtained, fully meeting the personalized needs of different lesion sites and thrombus properties for negative pressure intensity.

[0045] Example 2 This embodiment discloses another type of suction plug device, which differs from the first embodiment in that the structure of the threaded core rod 22 and the threaded sleeve 23 are different.

[0046] like Figures 6 to 8 As shown, in this embodiment, the one-way asymmetric thread 225 of the threaded core rod 22 is designed as a one-way ratchet thread. The tooth profile angle of its retracting force-bearing surface 225c is 45°~65°, the tooth profile angle of its advancing force-bearing surface is 0°~10°, the thread helix angle is 3°~8°, and the friction coefficient of the retracting force-bearing surface is... ; Friction angle of the retracting force-bearing surface The coefficient of friction of the forward force-bearing surface 225d The friction angle of the forward force-bearing surface at 225d Thread helix angle The friction angle is smaller than that of the forward-applying surface. And greater than the friction angle of the backward force-bearing surface. More preferably, the tooth angle of the retractable force-bearing surface 225c. The tooth profile angle is designed to be 60° with a forward force-bearing surface of 225d. The design angle is 5°, the thread helix angle is designed to be 8°, and the friction angle of the retraction force surface is 225°. The friction angle is 5°, and the forward force-bearing surface is 225d. The angle is 15°, which ensures that the positive force meets the mechanical self-locking condition, thus achieving forward locking and preventing further advancement; the reverse force does not meet the self-locking condition, thus allowing free rotation and retraction in the reverse direction, forming a unidirectional self-locking thread mechanism that can only retract and not advance, in order to maintain stable negative pressure.

[0047] like Figure 6 , Figure 7 and Figure 10 As shown, the threaded sleeve 23 includes a nut sleeve 232, a pressure relief button 233, and an unlocking fork 234. The inner wall of the nut sleeve 232 has a one-way thread, which, in conjunction with the threaded core rod 22, forms a transmission structure that allows movement in only one direction. The nut sleeve 232 itself possesses certain elastic properties, enabling controllable deformation (slight radial expansion) along its radial direction. The unlocking fork 234 forms a stable connection with the threaded sleeve 23 and also possesses good elastic properties, deforming under external force and returning to its original shape after the force is removed. The pressure relief button 233 and the unlocking fork 234 are connected by a mechanical connection. When the user presses the pressure relief button 233, the force is transmitted to the unlocking fork 234, causing it to deform. This causes the nut sleeve 232 to be pushed outward radially, ultimately causing the one-way thread on the inner wall of the nut sleeve 232 to completely disengage from the corresponding one-way asymmetrical thread 225 on the threaded core rod 22, thus achieving rapid unlocking of the threaded core rod 22.

[0048] like Figure 10As shown, specifically, the nut sleeve 232 used in this embodiment is not a complete cylindrical structure, but a non-circular sleeve with an axially open slot 235. The open slot 235 extends axially along the nut sleeve 232, so that the nut sleeve 232 forms two opposing force-bearing ends 236 on both sides of the open slot 235. Furthermore, the nut sleeve 232 has two functional areas in the axial direction: a connecting section near the far end and a threaded section near the proximal end. The connecting section is mainly used to achieve a fixed connection with the proximal end of the hollow cylinder 11, and can be assembled by bonding, welding or other reliable connection processes; the inner wall of the connecting section does not have a threaded structure and does not have radial deformation capability to ensure the structural strength and stability of the connection part. The threaded section has the aforementioned one-way thread machined on its inner wall, and the entire section has radial elastic deformation capability. When subjected to a radially outward force, the threaded section will slightly open radially, disengaging the one-way thread on its inner wall from the one-way asymmetrical thread 225 on the threaded core rod 22. Conversely, when the external force is removed, the threaded section re-closes under its own elasticity and / or external reset action, allowing the one-way thread to re-engage tightly with the threaded core rod 22, restoring the "only retracting, no advancing" one-way transmission function. The length ratio of the connecting section to the threaded section can be flexibly set according to actual usage requirements; they can be equal or unequal. The preferred option is that the axial length of the threaded section is greater than the axial length of the connecting section, and the axial length of the connecting section usually does not exceed one-third of the total length of the nut sleeve 232, in order to balance structural strength and functional realization. Nut sleeve 232 can be made of medical-grade plastic materials, such as polypropylene (PP), polycarbonate (PC) or ABS resin. These materials not only have good biocompatibility, but also have excellent mechanical and processing properties, making them suitable for demanding applications in the medical device field. The connecting section and the threaded section can be an integral structure formed axially. They are manufactured from the same piece of medical-grade plastic material and together form a non-circular nut sleeve with an axially open slot. During the manufacturing process, only the inner wall of the threaded section near the proximal end is machined with a unidirectional thread structure. No additional threads are machined on the inner wall of the connecting section. The open slot 235 extends axially along the nut sleeve 232 and runs through the entire axial length of the threaded section. Therefore, the threaded section retains a complete open slot structure, which enables it to have radial elastic deformation capability that can open and close. The connecting section does not have an open slot, or the open slot in the connecting section area is closed. This creates a difference in performance: the connecting section has no radial deformation, while the threaded section can have radial elastic deformation. This ensures the structural strength stability after the connecting section is connected to the hollow cylinder 11, and also meets the functional requirements of unidirectional meshing transmission and elastic deformation disengagement of the threaded section.

[0049] like Figure 9 and Figure 10As shown, the unlocking fork 234 is positioned at the opening 235 of the nut sleeve 232. The unlocking fork 234 itself is made of a material with a certain degree of toughness and elasticity, maintaining its initial shape when no external force is applied, undergoing controllable deformation under force, and returning to its original shape due to the elasticity of its material after the external force is released. Its material is preferably a medical-grade rigid plastic, such as polypropylene, polycarbonate, or ABS resin. The overall structure of the unlocking fork 234 includes a central pressure-bearing portion 2341 and two paddles 2342 extending from both sides of the pressure-bearing portion 2341. At least a portion of the pressure-bearing portion 2341 is exposed outward from the opening 235, facilitating contact with external operating elements (such as the pressure relief button 233) and the transmission of force; each paddle 2342 is connected to a corresponding force-bearing end 236 on the nut sleeve 232. To enhance connection reliability, a dedicated slot structure can be formed on the force-bearing end 236. The slot is a non-through blind slot with its opening on the end face of the force-bearing end 236. At least a portion of the lever 2342 is inserted into the slot through the opening, thereby achieving a secure fixation between the unlocking fork 234 and the nut sleeve 232. The lever 2342 can be provided with a limiting tooth 2343, and the slot has a groove that mates with the limiting tooth 2343. After the lever 2342 is inserted into the slot, the limiting tooth 2343 engages in the groove, preventing the lever 2342 from dislodging from the slot during operation. Only one limiting tooth 2343 can be provided, preferably located at the end of the lever 2342 furthest from the pressure-bearing part 2341, or multiple limiting teeth can be arranged at intervals.

[0050] like Figure 9 and Figure 10As shown, the pressure-bearing part 2341 can be configured as an arc-shaped structure, with its arc apex protruding outward from the opening slit 235, slightly extending beyond the outer surface of the nut sleeve 232, for easy identification and pressing by the operator. The upper end of the pressure-bearing part 2341 is directly connected to the pressure relief button 233, forming a linkage mechanism. Under normal operating conditions, the unlocking fork 234 continuously applies inward clamping force to the nut sleeve 232 based on its own elasticity, ensuring that the one-way thread on the inner wall of the nut sleeve 232 and the one-way asymmetrical thread 225 on the threaded core rod 22 remain engaged, thereby enabling the threaded core rod 22 to achieve a retracting action and possess a self-locking function. When pressure relief is required, simply press the pressure relief button 233. This action causes the pressure-bearing part 2341 to deform inward, thereby driving the two side levers 2342 to move synchronously away from the center, pushing the two force-bearing ends 236 to separate radially, ultimately causing the entire nut sleeve 232 to be radially opened. During this process, the one-way thread on the inner wall of the nut sleeve 232 completely disengages from the one-way asymmetrical thread 225 of the threaded core rod 22. The threaded core rod 22 thus loses its constraint and can move freely back and forth axially, achieving rapid pressure relief and reset. When the operator releases the pressure relief button 233, the nut sleeve 232 automatically resets under the combined action of its own material elasticity and the rebound force of the unlocking fork 234. If necessary, the nut sleeve 232 can also be manually tightened to assist in restoring its original shape, allowing it to tightly wrap around the threaded core rod 22 again, ensuring accurate re-engagement of the one-way thread and the one-way asymmetrical thread 225. The device then returns to the one-way locked state of "only backward movement is allowed, forward movement is prohibited."

[0051] In summary, the rotary suction mechanism 2 proposed in this embodiment has a convenient one-button pressure relief function. When the user presses the pressure relief button 233, the unlocking fork 234 responds quickly and opens the nut sleeve 232, disengaging the threaded engagement and allowing the threaded core rod 22 to move forward to complete the reset action. During this process, the one-way check valve 4 inside the hollow cylinder 11 closes simultaneously, effectively preventing backflow of liquid or gas due to the reset of the threaded core rod 22, thereby ensuring the safety and operational stability of the entire device.

[0052] The other structures and working methods of this embodiment are the same as those of Embodiment 1, and will not be described again here.

[0053] Example 3 like Figures 11 to 13 As shown, the difference between the suction plug device in this embodiment and that in Embodiment 1 is that the structures of the one-way check valve 4 and the suction piston 21 are different.

[0054] like Figures 11 to 13As shown, the hollow cylinder 11 used in this embodiment mainly consists of two parts: its main body is a cylindrical structure with a uniform inner diameter and moderate wall thickness, while the part near the distal end (i.e., the end that comes into contact with the blood vessel during use) is a thin-walled inverted conical structure. The inner diameter of this inverted conical part gradually increases from the distal end to the proximal end, and a silicone sealing ring 40 with good elasticity and sealing performance is arranged around the inner wall at the position where the inner diameter reaches its maximum value. A set of one-way check valves 41 with a segmented blade structure is also provided on the proximal side of the silicone sealing ring 40. The diameter of the one-way check valve 41 is slightly smaller than the inner diameter of the cylindrical main body of the hollow cylinder 11 and larger than the inner diameter of the silicone sealing ring 40, thereby ensuring effective cooperation during assembly and functional implementation. The segmented blade one-way check valve 41 is integrally molded using thermoplastic elastomer (TPE) material through injection molding, has good flexibility and resilience, and is pre-assembled inside the negative pressure chamber during the product assembly stage. When the rotating threaded core rod 22 retracts and creates a negative pressure environment in the negative pressure chamber, the two leaflets 42 of the one-way check valve 41 will automatically open along their central fixed axis toward the negative pressure chamber, thus allowing the negative pressure to be smoothly transmitted to the suction line connected to the blood vessel. When the suction action stops, the pressure difference between the negative pressure chamber and the blood vessel side decreases or even disappears rapidly. At this time, the leaflet one-way check valve 41 automatically closes due to the elastic restoring force of its material. The free edges of the two leaflets 42 are tightly attached to the inner surface of the silicone sealing ring 40, forming a reliable sealing interface, thereby effectively preventing the backflow of blood or thrombi and other substances, ensuring the safety and effectiveness of the operation.

[0055] The negative pressure gauge 3 is integrated and installed at the far end of the hollow cylinder 11 to monitor and provide feedback on the vacuum status inside the entire suction channel in real time, so that the operator can keep track of the negative pressure changes in a timely manner and improve the controllability and safety of the surgical procedure.

[0056] like Figure 11 and Figure 12 As further shown, in this embodiment, the suction piston 21 employs a single-ring sealing boss 214 made of silicone material at its sealing area 211. The distal edge of this sealing boss 214 adopts a smooth arc transition structure, which not only helps to more effectively prevent gas leakage during the reciprocating motion of the piston, but also significantly reduces the flow resistance generated when fluid passes through during suction, thereby improving the overall suction efficiency. At the same time, the outer diameter of the sealing boss 214 is slightly larger than the inner diameter of the hollow cylinder 11, ensuring that it can form a tight fit with the inner wall after being installed in the hollow cylinder 11. An interference fit of about 0.1 mm is provided between the two, which ensures good airtightness without affecting the smooth operation of the suction piston 21 due to excessive friction.

[0057] The other structures and working methods of this embodiment are the same as those of Embodiment 1, and will not be described again here.

[0058] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A device for drawing and removing a plunger, characterized in that, include: The main components of the negative pressure chamber include a hollow cylinder; The rotary suction mechanism includes a suction piston that mates with the inner wall of the hollow cylinder, a threaded core rod connected to the suction piston, and a threaded sleeve disposed near the end of the hollow cylinder. The threaded core rod is provided with a one-way asymmetrical thread; The threaded sleeve includes a nut sleeve, a pressure relief button, and an unlocking fork. The inner wall of the nut sleeve is provided with the one-way thread. The one-way asymmetrical thread and the one-way thread cooperate to form a one-way transmission structure that only allows the threaded core rod to retract in a direction away from the far end of the hollow cylinder, and does not allow it to advance in a direction close to the far end of the hollow cylinder. When the threaded core rod drives the suction piston to retract, it can create a negative pressure in the hollow cylinder. The nut sleeve has an opening slot, and the nut sleeve can deform radially. The unlocking fork is located at the opening and connected to the threaded sleeve; the unlocking fork can deform under force. The pressure relief button is connected to the unlocking fork. Pressing the pressure relief button causes the unlocking fork to deform, thereby opening the nut sleeve radially and disengaging the one-way thread from the one-way asymmetrical thread.

2. The suction thrombus device according to claim 1, characterized in that, The opening extends axially, and the nut is fitted into the opening to form two opposing force-bearing ends; The unlocking fork includes a pressure-receiving part and paddles respectively disposed on both sides of the pressure-receiving part. The pressure-receiving part is at least partially exposed outward from the opening, and each paddle is connected to a corresponding force-receiving end. The pressure-receiving part is connected to the pressure relief button. Pressing the pressure relief button can cause the pressure-receiving part to deform, thereby causing the paddle to move to both sides, so that the two force-receiving ends move away from each other in the radial direction.

3. The suction thrombus device according to claim 1, characterized in that, The hollow cylinder is equipped with a one-way check valve, which is located near the far end of the hollow cylinder. When a negative pressure is formed inside the hollow cylinder, the one-way check valve can be opened. The one-way check valve is a duckbill-shaped check valve, and the duckbill-shaped check valve is integrally injection molded with the hollow cylinder. Alternatively, the one-way check valve may be a leaf-shaped check valve.

4. The suction thrombus device according to claim 1, characterized in that, It also includes a negative pressure gauge located at the far end of the hollow cylinder, the negative pressure gauge being connected to the hollow cylinder and used to display the air pressure inside the hollow cylinder; The hollow cylinder has a branch pipe extending perpendicular to its axis at its distal end, and the branch pipe is integrally formed with the hollow cylinder. The negative pressure gauge is a Bourdon tube negative pressure gauge, and the pipeline of the Bourdon tube negative pressure gauge is seamlessly welded to the branch pipe.

5. The suction thrombus device according to claim 1, characterized in that, The unidirectional asymmetric thread is a unidirectional asymmetric sawtooth thread, an asymmetric rectangular thread, or a unidirectional ratchet thread. If the unidirectional asymmetric thread is a unidirectional asymmetric sawtooth thread, the tooth profile angle of the retracting force surface is 25°~35°, the tooth profile angle of the advancing force surface is 0°~10°, and the thread helix angle is 3°~8°. The thread helix angle is less than the friction angle of the advancing force surface and greater than the friction angle of the retracting force surface. If the unidirectional asymmetric thread is a unidirectional ratchet thread, the tooth profile angle of the retracting force surface is 45°~65°, the tooth profile angle of the advancing force surface is 0°~10°, and the thread helix angle is 3°~8°. The thread helix angle is less than the friction angle of the advancing force surface and greater than the friction angle of the retracting force surface.

6. The suction thrombus device according to claim 1, characterized in that, The hollow cylinder is connected to a flexible hose at its distal end, and a three-way valve is provided at the distal end of the flexible hose. The hollow cylinder, the flexible hose, and the three-way valve are integrally injection molded.

7. The suction thrombus device according to claim 1, characterized in that, The nut sleeve includes a connecting section and a threaded section arranged radially. The connecting section is fixedly connected to the hollow cylinder. The one-way thread is not provided on the inner wall of the connecting section, and the one-way thread is only provided on the inner wall of the threaded section. The axial length of the threaded section is greater than the axial length of the connecting section; The axial length of the connecting section does not exceed one-third of the total length of the nut sleeve.

8. The suction thrombus device according to claim 2, characterized in that, The force-bearing end is provided with a slot, which is a non-through blind slot with its opening opened on the end face of the force-bearing end, and at least a portion of the paddle is inserted into the slot from the opening. The paddle is provided with at least one limiting tooth, and the slot is provided with a groove that cooperates with the limiting tooth. The limiting tooth can be engaged in the groove to prevent the paddle from coming out of the slot.

9. The suction thrombus device according to claim 1, characterized in that, The suction piston includes a sealing area, a first connecting area, and a fixing area arranged sequentially along the direction from the distal end of the hollow cylinder toward its proximal end; The sealing area is provided with a single-ring or double-ring sealing boss. The outer diameter of the sealing boss is larger than the inner diameter of the hollow cylinder. The sealing boss is tightly fitted with the inner wall of the hollow cylinder, and the interference between the two is 0.05~0.1mm. The far end of the sealing area is provided with an arc-shaped or conical transition structure. The first connecting area is a cylindrical structure with an outer diameter smaller than that of the sealing boss. Multiple reinforcing ribs extending axially along the suction piston are provided on the outer side of the first connecting area. The multiple reinforcing ribs are evenly arranged circumferentially along the first connecting area. The fixing area has a concave groove, and the inner wall of the groove is provided with an elastic buckle for engaging with the distal end of the threaded core rod; the fixing area of ​​the suction piston is provided with a limiting component that cooperates with the distal end of the threaded sleeve to limit the maximum backward stroke of the threaded core rod.

10. The suction plug device according to claim 9, characterized in that, The threaded core rod includes a second connecting area, a threaded area, and an operating handle arranged sequentially along the direction from the far end to the near end of the hollow cylinder. The far end of the second connecting area is provided with an engaging protrusion that engages with the elastic snap. The outer surface of the threaded area is provided with the unidirectional asymmetrical thread. The operating handle is located at the near end of the threaded area.

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