Peripheral vessel catheter assembly for hemodialysis

Abstract

The invention relates to the technical field of medical instruments, provides a catheter assembly with flow regulation, backflow prevention and self-adaptive sealing functions, and particularly relates to a peripheral vessel catheter assembly for hemodialysis. The self-adaptive anti-backflow catheter mainly comprises a catheter body, a flow adjusting and anti-backflow linkage unit and a self-adaptive sealing unit. The independent cavities of the main channel and the auxiliary channel can avoid turbulent flow generated by mixing of high-flow blood and medicine in the single-cavity catheter, so that mechanical damage to blood cells is reduced, the flow adjusting and backflow preventing linkage unit accurately adjusts flow through a pressure induction type adjusting piece, a lever mechanism and simple mechanical transmission, and the flow adjusting effect is good. And a bistable silica gel membrane backflow blocking petal and an electromagnetic locking device are matched, so that backflow is reliably prevented. The hemodialysis device has excellent performance in the aspects of flow regulation, backflow prevention, sealing and self-cleaning, and the safety and effectiveness of hemodialysis are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and provides a catheter assembly with functions of flow regulation, anti - reflux and adaptive sealing, specifically a peripheral vascular catheter assembly for hemodialysis. Background Art

[0002] In hemodialysis treatment, as a key component connecting the patient's blood vessels and dialysis equipment, the performance of the peripheral vascular catheter directly affects the treatment effect, as well as the comfort and safety of the patient.

[0003] Existing peripheral vascular catheters have many problems. On the one hand, in terms of flow regulation, traditional catheters are difficult to accurately adapt to the blood flow requirements of patients at different treatment stages. Unstable flow control may lead to insufficient dialysis or damage to blood vessels. On the other hand, the anti - reflux function is insufficient. Blood reflux not only affects dialysis efficiency but also may cause complications such as infection. In addition, the sealing effect between the catheter and the blood vessel is not ideal, prone to blood leakage, and bacteria are likely to breed inside the catheter after long - term use. Lack of an effective self - cleaning mechanism further increases the risk of infection.

[0004] Therefore, it is of great clinical significance to develop a peripheral vascular catheter assembly for hemodialysis that can effectively solve the above problems. Summary of the Invention

[0005] The present invention proposes a peripheral vascular catheter assembly for hemodialysis, which solves the problems of single function, easy reflux, blockage and poor adaptability in the prior art through the synergistic action of a flow regulation and anti - reflux linkage unit, an adaptive sealing unit and a self - cleaning unit.

[0006] The technical solution of the present invention is as follows: A peripheral vascular catheter assembly for hemodialysis, comprising a catheter body, a flow regulation and anti - reflux linkage unit and an adaptive sealing unit, wherein:

[0007] The catheter body is composed of a proximal connecting part and a distal catheter tube body. The inner cavity of the catheter body is divided into a main channel and an auxiliary channel, and the inner wall of the main channel is coated with an anticoagulant nano - coating;

[0008] The flow regulation and anti - reflux linkage unit is integrated at the proximal end of the catheter body, and includes a pressure - sensitive regulating piece, a reflux - blocking valve and a lever mechanism, wherein:

[0009] The pressure - sensitive regulating piece is an arc - shaped elastic metal piece, which is connected to the flow control port of the main channel through a multi - stage lever mechanism. The fulcrum spacing of the lever mechanism is adjustable. The reflux - blocking valve operates in coordination with the flow regulation and anti - reflux linkage unit, wherein:

[0010] The flow rate regulation and anti - reflux linkage unit includes a pressure - sensitive regulating piece, a reflux - blocking flap, a lever mechanism, a fixing plate, a sector gear, a chute, a retaining rod, a rotating plate, a driver, a fixing rod, a vertical plate, a hollow slide plate, a magnetic metal piece, and an electromagnetic locking device;

[0011] The pressure - sensitive regulating piece is in contact connection with the catheter body. And due to the adjustable distance between the fulcrums of the lever mechanism, it can also be in contact connection with the reflux - blocking flap. The hollow slide plate is fixedly connected to the pressure - sensitive regulating piece. The hollow slide plate is slidably installed in the fixing plate. The vertical plate and the fixing plate are fixedly connected. A tooth groove meshing with the sector gear is provided on the bottom wall of the hollow slide plate. The hollow slide plate and the sector gear are meshingly connected. The fixing rod is fixed in the middle of the vertical plate. The sector gear is rotatably installed on the fixing rod. The chute is opened in the lower part of the sector gear. The retaining rod is slidably installed in the chute. The rotating plate and the retaining rod are fixedly connected. The rotating plate is rotatably installed at the lower part of the vertical plate. The output shaft of the driver is fixedly inserted behind the rotating plate and passes through the vertical plate;

[0012] Among them, the output shaft of the driver drives the rotating plate to rotate. The rotating plate drives the retaining rod to make a circular motion. The retaining rod drives the sector gear to swing left and right along the fixing rod in the chute. The sector gear drives the hollow slide plate to translate left and right along the fixing plate. The hollow slide plate thus drives the pressure - sensitive regulating piece to swing left and right along the lever mechanism. The pressure - sensitive regulating piece thus drives the pressing, releasing, and closing of the reflux - blocking flap of the catheter body;

[0013] The adaptive sealing unit is coated on the distal end of the catheter body and includes an expandable polymer ring.

[0014] As a preferred solution of the present invention, the reflux - blocking flap adopts a bistable silicone diaphragm, and a magnetic metal piece is embedded in the center of the diaphragm. An electromagnetic locking device is provided at the corresponding position of the catheter body.

[0015] As a preferred solution of the present invention, a micro air pump and a pressure feedback controller are provided inside the expandable polymer ring of the adaptive sealing unit. The air pump is communicated with the cavity of the ring body through a micro - channel.

[0016] As a preferred solution of the present invention, a piezoelectric ceramic displacement sensor is installed at the end of the lever mechanism. The sensor has a linear relationship with the opening area of the flow control port.

[0017] As a preferred solution of the present invention, the anti - coagulation nano - coating on the inner wall of the main channel is a titanium dioxide composite layer with a thickness of 500 nm and a coating porosity of 15%.

[0018] As a preferred solution of the present invention, it further includes a self - cleaning unit, which is composed of an ultrasonic generator and an annular piezoelectric transducer. The transducer vibrates at a frequency of 100 kHz with an amplitude of 5 μm and is evenly distributed circumferentially along the inner wall of the catheter.

[0019] The working principle and beneficial effects of the present invention are as follows:

[0020] By combining a pressure-sensing regulating piece with a multi-stage lever mechanism and a piezoelectric ceramic displacement sensor, the present invention can adjust the opening area of the flow control port in real time and accurately according to blood pressure. Under different physiological conditions, such as fluctuations in the patient's blood pressure or changes in the dialysis stage, it can ensure a stable blood flow that meets the treatment requirements, avoiding insufficient dialysis or vascular damage caused by unstable blood flow, and significantly improving the dialysis treatment effect.

[0021] The reflux blocking valve adopts a bistable silicone membrane combined with a magnetic metal sheet and an electromagnetic locking device. When there is a tendency of blood reflux, the electromagnetic locking device responds quickly to close the reflux blocking valve, effectively preventing blood reflux and reducing the risk of complications such as infection caused by blood reflux, ensuring the safety of the dialysis process.

[0022] The expandable polymer ring of the adaptive sealing unit can adjust its expansion degree in real time according to the blood vessel pressure with the help of a micro air pump and a pressure feedback controller, closely fitting the inner wall of the blood vessel to prevent blood leakage. This not only improves the patient's comfort but also reduces the risk of infection caused by blood leakage, providing a stable blood vessel access environment for dialysis treatment.

[0023] The ultrasonic generator of the self-cleaning unit and the annular piezoelectric transducer work together, vibrating at a frequency of 100 kHz and an amplitude of 5 μm, evenly distributed circumferentially along the inner wall of the catheter. The high-frequency vibration can effectively remove bacteria and dirt attached to the inner wall of the catheter, keep the catheter clean, reduce bacterial growth, extend the service life of the catheter, and reduce the risk of infection for patients during long-term dialysis treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0025] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 is a schematic diagram of the overall structure of the present invention from another perspective;

[0027] Figure 3 is for the present invention Figure 2 magnified schematic diagram of the structure at point A;

[0028] Figure 4 is a schematic diagram of the cross-sectional structure of the catheter body of the present invention.

[0029] In the figure: 100, catheter body; 101, main channel; 102, auxiliary channel; 200, flow regulation and anti-backflow linkage unit; 201, pressure-sensing regulating piece; 202, backflow blocking flap; 203, lever mechanism; 204, fixing plate; 205, sector gear; 206, chute; 207, retaining rod; 208, rotating plate; 209, driver; 210, fixing rod; 211, vertical plate; 212, hollow sliding plate; 213, magnetic metal sheet; 214, electromagnetic locking device; 300, adaptive sealing unit; 301, expandable polymer ring; 302, micro air pump; 303, pressure feedback controller. Specific implementation mode

[0030] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0031] Embodiment 1

[0032] As Figures 1 to 4 shown, this embodiment proposes a peripheral blood vessel catheter assembly for hemodialysis, including a catheter body 100, a flow regulation and anti-backflow linkage unit 200 and an adaptive sealing unit 300, wherein:

[0033] The catheter body 100 is composed of a proximal connecting portion and a distal catheter tube body. The inner cavity of the catheter body 100 is divided into a main channel 101 and an auxiliary channel 102, and the inner wall of the main channel 101 is coated with an anticoagulant nano-coating;

[0034] The flow regulation and anti-backflow linkage unit 200 is integrated at the proximal end of the catheter body 100, and includes a pressure-sensing regulating piece 201, a backflow blocking flap 202 and a lever mechanism 203, wherein:

[0035] The pressure-sensing regulating piece 201 is an arc-shaped elastic metal sheet, which is connected to the flow control port of the main channel 101 through a multi-stage lever mechanism 203. The fulcrum spacing of the lever mechanism 203 is adjustable. The backflow blocking flap 202 cooperates through the flow regulation and anti-backflow linkage unit 200, wherein:

[0036] The flow regulation and anti-backflow linkage unit 200 includes a pressure-sensing regulating piece 201, a backflow blocking flap 202, a lever mechanism 203, a fixing plate 204, a sector gear 205, a chute 206, a retaining rod 207, a rotating plate 208, a driver 209, a fixing rod 210, a vertical plate 211, a hollow sliding plate 212, a magnetic metal sheet 213 and an electromagnetic locking device 214;

[0037] The pressure-sensitive regulating piece 201 is in contact connection with the catheter body 100. And due to the adjustable distance between the fulcrums of the lever mechanism 203, it can also be in contact connection with the reflux blocking flap 202. The hollow slide plate 212 is fixedly connected to the pressure-sensitive regulating piece 201. The hollow slide plate 212 is slidably installed in the fixing plate 204. The vertical plate is fixedly connected to the fixing plate 204. A tooth groove meshing with the sector gear 205 is provided on the bottom wall of the hollow slide plate 212. The hollow slide plate 212 is meshingly connected with the sector gear 205. The fixing rod 210 is fixed in the middle of the vertical plate 211. The sector gear 205 is rotatably installed on the fixing rod 210. The chute 206 is opened in the lower part of the sector gear 205. The retaining rod 207 is slidably installed in the chute 206. The rotating plate 208 is fixedly connected to the retaining rod 207. The rotating plate 208 is rotatably installed in the lower part of the vertical plate 211. The output shaft of the driver 209 is fixedly inserted behind the rotating plate 208 and passes through the vertical plate 211;

[0038] Among them, the output shaft of the driver 209 drives the rotating plate 208 to rotate. The rotating plate 208 drives the retaining rod 207 to make a circular motion. The retaining rod 207 drives the sector gear 205 to swing left and right along the fixing rod 210 in the chute 206. The sector gear 205 drives the hollow slide plate 212 to translate left and right along the fixing plate 204. The hollow slide plate 212 thus drives the pressure-sensitive regulating piece 201 to swing left and right along the lever mechanism 203. The pressure-sensitive regulating piece 201 thus drives the pressing, releasing and taking in of the catheter body 100, and drives the closing and opening of the reflux blocking flap 202;

[0039] The adaptive sealing unit 300 is coated on the distal end of the catheter body 100 and includes an expandable polymer ring 301.

[0040] As Figures 1 to 4 shown, the reflux blocking flap 202 adopts a bistable silicone membrane. A magnetic metal sheet 213 is embedded in the center of the membrane. An electromagnetic locking device 214 is provided at the corresponding position of the catheter body 100;

[0041] A micro air pump 302 and a pressure feedback controller 303 are provided inside the expandable polymer ring 301 of the adaptive sealing unit 300. The air pump is communicated with the cavity of the ring body through a microchannel;

[0042] A piezoelectric ceramic displacement sensor is installed at the end of the lever mechanism 203. The sensor has a linear relationship with the opening area of the flow control port;

[0043] The anticoagulant nano-coating on the inner wall of the main channel 101 is a titanium dioxide composite layer with a thickness of 500 nm and a coating porosity of 15%;

[0044] It also includes a self-cleaning unit, which consists of an ultrasonic generator and an annular piezoelectric transducer. The transducer vibrates at a frequency of 100 kHz with an amplitude of 5 μm and is evenly distributed circumferentially along the inner wall of the catheter.

[0045] In this embodiment, when the blood pressure fluctuates, the arc-shaped elastic metal sheet of the pressure-sensing regulating piece 201 generates a displacement signal due to deformation. Through the meshing transmission between the tooth groove of the hollow slide plate 212 and the sector gear 205, the micron-level displacement is amplified into a millimeter-level movement:

[0046] After receiving the pressure signal, the output shaft of the driver 209 drives the rotating plate 208 to rotate with a 0.5° step angle, driving the retaining rod 207 to perform an eccentric circular motion within the sliding groove 206;

[0047] The retaining rod 207 pushes the sector gear 205 to swing left and right at a frequency of 8 Hz, and converts the rotational motion into a linear displacement of the hollow slide plate 212 through the gear-rack transmission;

[0048] The hollow slide plate 212 drives the pressure-sensing regulating piece 201 to deflect, and controls the opening and closing of the flow control port through the three-stage lever mechanism 203, and the opening adjustment response time ≤ 80 ms;

[0049] When it is detected that the blood backflow speed > 10 cm / s, the swing angle of the sector gear 205 exceeds the threshold value (15°), and the silicone membrane of the backflow blocking flap 202 is triggered by the link group to switch from the straight state to the curved state (curvature radius 2 mm), and the closing rate ≥ 95%;

[0050] If the backflow continues > 0.5 s, the electromagnetic locking device 214 is energized to generate a 0.8 T magnetic field, increasing the adsorption force between the central magnetic metal sheet 213 of the membrane and the catheter wall to 20 N, and raising the sealing pressure to 150 mmHg.

[0051] Embodiment 2

[0052] In this embodiment, after the catheter is inserted into the blood vessel, the pressure feedback controller 303 monitors the blood vessel wall pressure in real time (sampling frequency 100 Hz), and dynamically adjusts the inflation rate of the micro air pump 302 through the PID algorithm:

[0053] When the blood vessel diameter changes by ±1 mm, the air pump completes the expansion / contraction of the polymer ring within 2 s (expansion rate adjustment gradient 5% / s);

[0054] The microporous structure of the shape memory alloy stent unfolds into a three-dimensional network (pore diameter expands to 150 μm) under the trigger of body temperature (37°C), forming a rigid-flexible composite seal with the polymer ring, making the blood vessel contact stress evenly distributed (pressure fluctuation < 5%).

[0055] The distal end of the catheter adopts a gradient hardness design (proximal Shore A75 → distal Shore A45), combined with the eddy flow effect of the spiral guide groove (Reynolds number Re = 500-800), to reduce the scouring effect of blood flow on the catheter position and make the displacement rate <0.1mm / h.

[0056] Example 3

[0057] The titanium dioxide composite layer on the inner wall of the main channel 101 produces a photocatalytic reaction when in contact with blood (even without external light), and the surface hydroxyl radical concentration reaches 10^4 / mm2, which reduces protein adsorption energy by 40%;

[0058] The coating porosity is designed to be 15%, forming a micro-nano composite structure, which increases the critical shear stress of platelet adhesion to 2.5Pa (1.2Pa for ordinary catheters).

[0059] The annular piezoelectric transducer produces cavitation effect at a frequency of 100kHz and an amplitude of 5μm, forming cavitation bubbles with a diameter of 50-100μm at the tube wall interface:

[0060] When the cavitation bubble collapses, a local 100MPa high-pressure microjet is generated, and the critical shear force for removing attachments reaches 10N / mm2;

[0061] It works synergistically with the anticoagulant coating to prolong the thrombosis time to three times that of ordinary catheters (in vitro experiments showed no thrombosis for 72 hours).

[0062] Among them, the implementation method of the catheter body 100 is:

[0063] The catheter body 100 consists of a proximal connecting part and a distal catheter body. The inner cavity is divided into a main channel 101 and an auxiliary channel 102. The inner wall of the main channel 101 is coated with an anti-coagulation nano coating with a thickness of 500nm and a porosity of 15%, which effectively prevents thrombosis.

[0064] Implementation method of flow regulation and backflow prevention linkage unit 200:

[0065] The pressure-sensitive regulating piece 201 is connected to the flow control port through a multi-stage lever mechanism 203. The pivot distance of the lever mechanism 203 is adjustable within a range of 10% to 25% of the total length of the lever.

[0066] The backflow blocking flap 202 is made of a bistable silicone diaphragm, a magnetic metal sheet 213 is embedded in the center of the diaphragm, and an electromagnetic locking device 214 is provided at a corresponding position of the catheter body 100, and the locking response time is less than 50ms.

[0067] The driver 209 drives the rotating plate 208 to rotate. The rotating plate 208 drives the retaining rod 207 to make a circular motion. The retaining rod 207 drives the sector gear 205 to swing left and right within the sliding groove 206. The sector gear 205 drives the hollow slide plate 212 to translate left and right. The hollow slide plate 212 drives the pressure-sensitive adjusting piece 201 to swing along the lever mechanism 203, realizing the opening and closing of the flow control port and the closing of the reflux blocking flap 202.

[0068] Embodiment of the adaptive sealing unit 300:

[0069] The inflatable polymer ring 301 realizes dynamic inflation through the micro air pump 302 and the pressure feedback controller 303. The adjustable range of the inflation rate is 20%-150%, ensuring a tight fit with the patient's blood vessel.

[0070] Embodiment of the self-cleaning unit:

[0071] The ultrasonic generator drives the annular piezoelectric transducer to vibrate at a frequency of 100 kHz and an amplitude of 5 μm, which are evenly distributed circumferentially along the inner wall of the catheter to effectively remove the attached substances.

[0072] Among them, the double-lumen design of the main channel 101 and the auxiliary channel 102 set in the peripheral blood vessel catheter assembly for hemodialysis has the following core advantages:

[0073] Main channel 101 (main blood dialysis pathway):

[0074] Undertakes the core function of extracorporeal blood circulation and is dedicated to high-flow blood exchange (usually 200-400 mL / min). The anticoagulant nano-coating (such as titanium dioxide composite layer) on its inner wall can minimize thrombus formation and ensure dialysis efficiency.

[0075] Auxiliary channel 102 (multifunctional pathway):

[0076] Used to achieve the following extended functions:

[0077] Drug infusion: Inject anticoagulants (such as heparin) or emergency drugs directly during dialysis;

[0078] Pressure monitoring: Real-time detection of changes in blood vessel pressure to provide feedback signals for flow regulation;

[0079] Emergency flushing: Quickly remove air bubbles or microthrombi to avoid the risk of blockage.

[0080] 2. Reduce the risk of blood damage and turbulence

[0081] Shunt design reduces turbulence:

[0082] The independent cavities of the main channel 101 and the auxiliary channel 102 can avoid the turbulence generated by the mixing of high-flow blood with drugs / irrigation fluids in a single-cavity catheter (the Reynolds number is reduced by 30%-50%), thereby reducing the mechanical damage to blood cells (such as the risk of hemolysis is reduced by more than 20%).

[0083] Reducing blood mixing interference:

[0084] The main channel 101 is dedicated to hemodialysis, and the auxiliary channel 102 is used for other operations, avoiding direct impact of drugs or irrigation fluids on the main blood flow and maintaining the stability of the dialysis process.

[0085] 3. Enhancing safety and emergency response capabilities

[0086] Redundant safety guarantee:

[0087] If the main channel 101 is temporarily blocked by a thrombus, the auxiliary channel 102 can be used as an emergency passage to maintain partial dialysis function and gain time for clinical treatment;

[0088] The auxiliary channel 102 can integrate sensors (such as pressure and temperature probes) to monitor the catheter status in real time and give early warnings of abnormalities.

[0089] Reducing the risk of infection:

[0090] The physical isolation design of the main channel 101 and the auxiliary channel 102 can avoid damage to the inner wall coating of the main channel 101 during drug infusion or irrigation operations, reducing the risk of bacterial colonization.

[0091] 4. Optimizing the catheter structure and long-term service performance

[0092] Balancing structural strength and flexibility:

[0093] The main channel 101 uses a high-hardness material (such as Shore A75) to ensure anti-collapse ability, and the auxiliary channel 102 uses a flexible material (such as Shore A45) to adapt to blood vessel bending, making the overall catheter more durable in a complex blood vessel environment.

[0094] Extending the service life:

[0095] By regularly flushing the main channel 101 (such as with normal saline or citric acid solution) through the auxiliary channel 102, early thrombi or protein deposits on the inner wall of the main channel 101 can be removed, delaying blockage (experiments show that the service life is extended by 30%-50%).

[0096] 5. Improving the flexibility of clinical operations

[0097] Parallel operation ability:

[0098] Medical staff can complete drug infusion or sampling through the auxiliary channel 102 during dialysis without interrupting the treatment, improving efficiency (the single treatment time is shortened by 10%-15%).

[0099] Adapt to complex treatment needs:

[0100] For patients who require combined treatment (such as dialysis + plasma exchange), the main and auxiliary channels can undertake different functions respectively, avoiding multiple catheterizations.

[0101] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A peripheral vascular catheter assembly for hemodialysis, characterized in that: It includes a catheter body, a flow regulation and backflow prevention linkage unit and an adaptive sealing unit, wherein: The catheter body is composed of a proximal connecting part and a distal catheter body, the inner cavity of the catheter body is divided into a main channel and an auxiliary channel, and the inner wall of the main channel is coated with an anti-coagulation nano coating; The flow regulation and backflow prevention linkage unit is integrated at the proximal end of the catheter body, and includes a pressure-sensitive regulating piece, a backflow blocking valve and a lever mechanism, wherein: The pressure-sensitive regulating piece is an arc-shaped elastic metal piece, which is connected to the flow control port of the main channel through a multi-stage lever mechanism. The fulcrum spacing of the lever mechanism is adjustable. The backflow blocking flap cooperates with the backflow prevention linkage unit through flow regulation, wherein: The flow regulation and backflow prevention linkage unit includes a pressure-sensitive regulating plate, a backflow blocking flap, a lever mechanism, a fixing plate, a sector gear, a slide groove, a retention rod, a rotating plate, a driver, a fixing rod, a vertical plate, a hollow slide plate, a magnetic metal sheet and an electromagnetic locking device; The pressure-sensitive regulating piece is in contact with the catheter body, and because the distance between the fulcrums of the lever mechanism is adjustable, it can also be in contact with the backflow blocking flap. The hollow slide is fixedly connected to the pressure-sensitive regulating piece, and the hollow slide is slidably installed in the fixed plate. The vertical plate and the fixed plate are fixedly connected. A tooth groove meshing with the fan gear is provided on the bottom wall of the hollow slide. The hollow slide is meshed with the fan gear. The fixed rod is fixed to the middle of the vertical plate, and the fan gear is rotatably installed on the fixed rod. The slide groove is provided at the lower part of the fan gear, and the retention rod is slidably installed in the slide groove. The rotating plate and the retention rod are fixedly connected, and the rotating plate is rotatably installed at the lower part of the vertical plate. The output shaft of the driver is fixedly inserted at the rear side of the rotating plate and passes through the vertical plate. The output shaft of the driver drives the rotating plate to rotate, the rotating plate drives the retention rod to draw a circle, the retention rod drives the fan gear in the slide groove to swing left and right along the fixed rod, the fan gear drives the hollow slide plate to translate left and right along the fixed plate, the hollow slide plate drives the pressure-sensitive adjustment plate to swing left and right along the lever mechanism, the pressure-sensitive adjustment plate drives the compression and retraction of the catheter body, and drives the closing of the backflow blocking valve; The adaptive sealing unit is coated on the distal end of the catheter body and comprises an expandable polymer ring.

2. A peripheral vascular catheter assembly for hemodialysis according to claim 1, characterized in that: The backflow blocking flap adopts a bistable silicone diaphragm, a magnetic metal sheet is embedded in the center of the diaphragm, and an electromagnetic locking device is arranged at the corresponding position of the catheter body.

3. A peripheral vascular catheter assembly for hemodialysis according to claim 2, characterized in that: A micro air pump and a pressure feedback controller are arranged inside the expandable polymer ring of the adaptive sealing unit, and the air pump is connected with the ring body cavity through a microchannel.

4. A peripheral vascular catheter assembly for hemodialysis according to claim 3, characterized in that: A piezoelectric ceramic displacement sensor is installed at the end of the lever mechanism, and the sensor is linearly related to the opening area of ​​the flow control port.

5. A peripheral vascular catheter assembly for hemodialysis according to claim 4, characterized in that: The anti-coagulation nano coating on the inner wall of the main channel is a titanium dioxide composite layer with a thickness of 500 nm and a coating porosity of 15%.

6. A peripheral vascular catheter assembly for hemodialysis according to claim 5, characterized in that: It also includes a self-cleaning unit, which consists of an ultrasonic generator and an annular piezoelectric transducer. The transducer vibrates at a frequency of 100kHz with an amplitude of 5μm and is evenly distributed along the circumference of the inner wall of the catheter.

Images