Microwave ablation thrombus catheter

Abstract

The invention belongs to the technical field of medical instruments, and particularly relates to a microwave ablation thrombus catheter. A water tank is installed in the handle and connected with the catheter body and the microwave ablation connector, a water inlet capillary and a water outlet capillary penetrate into the water tank, a coaxial cable is arranged between the water inlet capillary and the water outlet capillary, and a sliding block is arranged on the water tank and connected with a spring. The outer layer of the catheter main body is an outer-layer tube, the middle layer is a middle reinforcing layer, the inner layer is a lining, and the center is a cavity; the outer-layer pipe is provided with a plurality of symmetrical lining guide wire cavity channels, lining guide wires penetrate into the lining guide wire cavity channels respectively, wire drawing cavity channels are formed between the lining guide wire cavity channels, and wire drawing penetrates into the wire drawing cavity channels and is connected with a protective umbrella and a connecting sliding block respectively; the catheter body is connected with a catheter needle, the catheter needle is connected with a guide wire, a sliding shaft is arranged on the guide wire, and the sliding shaft is connected with a net wire of a protective umbrella. Residual thrombus is removed through microwaves, thrombus extraction success is improved, and risks are reduced.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, and in particular relates to microwave ablation catheters for thrombi. Background Technology

[0002] Intravascular thrombosis is a significant factor contributing to cardiovascular and cerebrovascular diseases (such as myocardial infarction and stroke) and peripheral vascular diseases, seriously threatening human life and health. Traditional thrombosis treatments include thrombolysis, mechanical thrombectomy, and surgery. However, thrombolysis has limitations such as a high risk of bleeding and poor efficacy against old thrombi; while mechanical thrombectomy can directly remove thrombi, its complete recanalization rate remains to be improved for firmly attached old thrombi or diffuse thrombi, and there is a risk of damage to the vascular intima. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the object of the present invention is to provide a microwave ablation thrombus catheter.

[0004] To achieve the above and other related objectives, the present invention provides the following technical solutions: The microwave ablation thrombosis catheter includes a handle containing a water tank. The front end of the water tank is connected to the catheter body, and the rear end of the water tank is connected to the microwave ablation connector. The water tank is externally inserted into inlet and outlet capillaries. A coaxial cable is provided between the inlet and outlet capillaries. Part of the coaxial cable is inside the catheter body, and part is inside the water tank. The water tank has a slider connected to a spring. The conduit body has multiple layers: an outer tube, a middle reinforcing layer, an inner liner, and a central cavity. The inlet capillary tube, outlet capillary tube, and part of the coaxial cable are all located inside the cavity of the conduit body. The outer tube has multiple symmetrical inner lining guide wire channels, each of which inserts an inner lining guide wire. A drawing wire channel is provided between the inner lining guide wire channels, through which a drawing wire is inserted. One end of the drawing wire is connected to the rear end of the protective umbrella, and the other end of the drawing wire is connected to a slider. The front end of the intermediate reinforcing layer is connected to the second imaging ring, the front end of the catheter body is connected to the catheter needle, the front end of the catheter needle is connected to the guidewire, the guidewire has a sliding shaft, the sliding shaft is connected to the mesh wire of the protective umbrella, and the front end of the protective umbrella is connected to the first imaging ring.

[0005] Preferably, the inlet capillary tube and the outlet capillary tube pass through the water tank into the main body of the conduit.

[0006] Preferably, the two ends of the coaxial cable are connected to the catheter needle and the microwave ablation connector, respectively. The microwave ablation connector is connected to an external microwave ablation device to provide microwave energy to the catheter needle.

[0007] Preferably, the ends of both the inlet capillary tube and the outlet capillary tube are connected to a water pipe Luer connector, which is connected to an external water inlet / outlet device.

[0008] Preferably, the water tank is equipped with a thermistor; the inner lining is a PTFE membrane, and the outer tube, inlet capillary tube, and outlet capillary tube are all hollow tubes made of PEEK material.

[0009] Preferably, the inner guidewire is inserted into the inner guidewire cavity from outside the handle, allowing the pushing and retraction of the inner guidewire to be controlled from outside the handle.

[0010] Preferably, the second imaging ring is located inside the main body of the catheter, with the catheter needle on the front side of the second imaging ring and the inlet capillary and outlet capillary on the rear side.

[0011] Preferably, the front end of the protective umbrella is connected to the developing ring 1, and the developing ring 1 and the front end of the protective umbrella are fixed on the guide wire. The developing ring 1, the front end of the protective umbrella, and the sliding shaft are all on the guide wire and arranged in order of distance from the handle, with the developing ring 1 being the furthest, followed by the front end of the protective umbrella and the sliding shaft in that order.

[0012] Preferably, the catheter needle is a SUS304 needle, and the surface of the catheter needle is coated with PTFE.

[0013] Preferably, the catheter needle is an SUS304 needle, and the surface of the catheter needle is coated with a lubricating coating. The preparation method of the lubricating coating includes the following steps: The catheter needle was immersed in NaOH solution for activation, rinsed clean, dried, immersed in ethanol solution containing IPTS, and then dried to obtain the pretreated catheter needle. PDMS-OH was added to ethanol and stirred until homogeneous; then an ionic liquid was added, stirred, and sonicated to form a coating solution. Immerse the pretreated catheter needle in the coating solution and let it stand; slowly pull out the needle and let it dry to form a lubricating coating on the surface of the catheter needle. Among them, the ionic liquid includes 1-ethyl-3-methylimidazolium dihydrogen phosphate.

[0014] It should be noted that immersion in NaOH solution can activate the surface of the catheter needle, while immersion in ethanol solution containing IPTS can form an active silane layer on the surface of the catheter needle. More specifically, 1) PDMS-OH is the main chain carrier, serving as a flexible main chain material that provides the basic film-forming properties and low friction performance of the coating; the molecular chain segments of PDMS-OH are helically randomly coiled, which can form a sliding low-friction layer on the surface; PDMS-OH has a low dielectric constant and does not easily absorb microwave energy, which is beneficial for suppressing microwave hotspots. 2) Ionic liquid is the functional enhancer, with a polar ion pair structure, possessing the characteristics of anti-protein adsorption, low migration, and microwave absorption buffering; the ionic liquid is dispersed in the PDMS matrix, forming an embedded ionic liquid region, which is stably bound through van der Waals forces and ion pair interactions; it can form a highly polar, non-adhesive hydration layer on the surface, inhibiting protein deposition and cell adhesion; the polar ion pairs can absorb some energy in the microwave field and release it slowly, mitigating local heat accumulation. 3) IPTS undergoes a hydrolysis-condensation reaction on the metal surface, forming metal-O-Si bonds; simultaneously, it can form weak chemical bonds with the residual hydroxyl groups in the PDMS chain segments or with the N- of the imidazole ring or the O- of the phosphate group in the ionic liquid; acting as a "molecular glue," it forms a covalent anchoring interface between the coating and the substrate, preventing delamination or erosion under microwave conditions. 4) The PDMS-OH matrix is ​​not easily coupled to microwaves, and the ionic liquid can absorb some energy and release it, acting as a buffer.

[0015] The beneficial effects of this invention are: 1. This invention provides a microwave ablation thrombus catheter, an interventional device for removing refractory thrombi in nerves and peripheral blood vessels. The catheter is delivered to the thrombus blockage site via minimally invasive surgery. A microwave ablation device is connected to the catheter handle, and microwave energy is used to heat the distal end of the catheter, thereby thermally ablating and detaching the refractory thrombus. In addition, a protective shield is connected to the distal end of the catheter to prevent the thermally ablated thrombus plaque from flowing further downstream and causing blockages in other blood vessels. This invention balances safety (avoiding vascular damage) and effectiveness (rapidly restoring blood flow), while also preventing secondary blockages caused by dislodged thrombi (the protective shield catches the dislodged thrombus). It is particularly suitable for the treatment of acute ischemic stroke (AIS), improving the success rate of thrombectomy by removing residual thrombi using microwaves and reducing the risk of secondary thrombus formation.

[0016] More specifically, this invention can determine the specific location of a patient's thrombus blockage through medical image analysis, and then deliver a microwave ablation thrombus catheter to the designated site of the lesion through minimally invasive intervention to remove the thrombus.

[0017] 2. Currently, the mainstream thrombectomy devices on the market include thrombectomy catheters, thrombectomy stents, etc. When dealing with tortuous and thin blood vessels, thrombectomy catheters have problems such as poor positioning and easy kinking. In addition, traditional guiding catheters and thrombectomy catheters have strict requirements on the peak breaking force of the catheter. Some products reduce the peak breaking force of the distal end of the catheter in order to improve distal flexibility, which may cause the catheter to break during use and ultimately affect the operation.

[0018] The conduit body of the present invention has multiple layers: an outer tube, a middle reinforcing layer, an inner liner, and a cavity in the center. The inlet capillary tube, the outlet capillary tube, and part of the coaxial cable are all inside the cavity of the conduit body. The intermediate reinforcing layer employs an integrated thiazo tube engraving technology, which involves engraving a single thiazo tube with meshes of varying densities to meet flexibility requirements. This improves catheter flexibility while ensuring that the peak tensile strength meets specifications. Simultaneously, the intermediate reinforcing layer possesses good mechanical strength, providing support for the outer tube, inlet capillary, outlet capillary, and coaxial cable, preventing kinking when passing through tortuous blood vessels.

[0019] 3. This invention offers precise positioning. Under DSA angiography, the microwave ablation thrombus catheter can accurately locate the thrombus lesion through the two contrast rings at the distal end of the catheter. The distal end of the catheter features a built-in protective umbrella. When the thrombus melts and detaches, it can drift into the protective umbrella with the blood flow. The contrast ring at the front end of the protective umbrella accurately locates the specific position of the thrombus. Furthermore, the contrast ring and the front end of the protective umbrella are fixed to the guidewire. The rear end of the umbrella has four pull wires that pass through the outer layer and converge at the handle end, connecting to the slider.

[0020] 4. The catheter needle of this invention is an SUS304 needle. The surface of the catheter needle is coated with a coating. When the catheter is working, when microwave heat is transferred to the catheter needle, the coating can prevent the needle from sticking to the blood vessel wall or other tissues, thereby improving the ablation effect and ablation efficiency.

[0021] More specifically, coating the catheter needle surface with PTFE or a lubricating coating not only prevents tissue adhesion during ablation but also reduces friction, improves operational smoothness, and reduces the risk of vascular wall damage. Experimental results show that the lubricating coating (Example 5) has lower sliding friction than the PTFE coating (Example 3), demonstrating superior clinical suitability.

[0022] 5. The handle of this invention is equipped with a water tank, through which two capillary tubes extend: one is an inlet capillary tube, and the other is an outlet capillary tube. During normal operation of the ablation catheter, coolant enters the entire catheter lumen through the inlet capillary tube and flows out through the outlet capillary tube, forming a closed loop. The water tank contains a thermistor, which can monitor the temperature of the distal end of the catheter and the catheter needle tip in real time. The temperature of the catheter needle tip is controlled by adjusting the water flow rate on the microwave ablation device to prevent over-ablation and thermal damage to the blood vessel wall or other tissues.

[0023] 6. The outer tube, inlet capillary tube, and outlet capillary tube are hollow tubes made of PEEK material. PEEK is a polymer material with good mechanical properties, and it is resistant to high temperature, impact, acid and alkali, wear, fatigue, and radiation, as well as having good electrical properties. The selection of this material can ensure that the tube body and capillary tube at the needle tip can withstand the heat impact generated by the high temperature during microwave ablation. In addition, the outer tube has good flexibility and can follow the shape changes of the tortuous blood vessel to shuttle and move inside the blood vessel, ensuring that it will not break under repeated bending and pushing.

[0024] 7. The overall flexibility and support of the microwave ablation thrombosis catheter of this invention can be switched at will. The switching principle is as follows: the outer tube has 4 inner guidewire lumens through which 4 inner guidewires can be inserted. When the catheter passes through tortuous blood vessels and better flexibility of the catheter is required, the inner guidewires can be withdrawn, thus improving the flexibility of the distal end of the catheter. When the catheter is delivered to the designated lesion site, the catheter needs to increase its support to support the catheter lumen and ensure the normal flow of water in and out of the capillary. The entire operation process only requires pushing or withdrawing the inner guidewires to achieve the switching between catheter flexibility and support. Attached Figure Description

[0025] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0026] In the attached diagram: Figure 1 This is a schematic diagram of the overall structure of the microwave ablation thrombus catheter of the present invention; Figure 2 This is a partial structural diagram of microwave ablation of thrombi according to the present invention (excluding the intermediate reinforcing layer); Figure 3 This is a partial anatomical diagram of the distal end of the microwave ablation thrombus catheter of this invention; Figure 4 This is a circumferential cross-sectional view of the microwave ablation thrombus catheter of the present invention.

[0027] The markings in the diagram are as follows: 1. Imaging ring one, 2. Protective umbrella, 3. Sliding shaft, 4. Guide wire, 5. Catheter needle, 6. Pulling wire, 7. Inner liner guide wire, 8. Outer tube, 9. Inlet capillary tube, 10. Outlet capillary tube, 11. Slider, 12. Spring, 13. Thermistor, 14. Water pipe Luer connector, 15. Microwave ablation connector, 16. Coaxial cable, 17. Handle, 18. Water tank, 19. Intermediate reinforcing layer, 20. Imaging ring two, 21. Inner liner guide wire channel, 22. Pulling wire channel, 23. Inner liner. Detailed Implementation

[0028] The applicant will now describe the embodiments of the present invention in detail. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Furthermore, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized by referring to existing literature or known methods. For reactions or test conditions not listed, they are all conventional techniques readily available to those skilled in the art. The terminology used in this invention is common in the art, and its meaning will be clearly understood by those skilled in the art; therefore, it will not be elaborated upon individually.

[0029] Example 1 This invention provides a microwave ablation thrombus catheter, which is divided into three parts: a handle assembly, a catheter body, and a distal functional component. The handle assembly is connected to the catheter body, and the catheter body is connected to the distal functional component.

[0030] The handle assembly includes a slider 11, a spring 12, a thermistor 13, a water pipe Luer connector 14, a microwave ablation connector 15, a handle 17, and a water tank 18.

[0031] The catheter body includes an outer tube 8, an inner guidewire 7, an inlet capillary tube 9, an outlet capillary tube 10, a coaxial cable 16, an intermediate reinforcing layer 19, a second imaging ring 20, an inner guidewire cavity 21, a wire drawing cavity 22, and an inner liner 23.

[0032] The remote functional components include a developing ring 1, a protective umbrella 2, a sliding shaft 3, a guide wire 4, a needle 5, and a drawing wire 6.

[0033] The handle 17 contains a water tank 18, the front end of which is connected to the main body of the conduit, and the rear end of which is connected to the microwave ablation connector 15.

[0034] Two capillary tubes are inserted into the water tank 18 from the outside: one is the inlet capillary tube 9, and the other is the outlet capillary tube 10. Furthermore, the inlet capillary tube 9 and the outlet capillary tube 10 are inserted into the main body of the conduit from the water tank 18.

[0035] A coaxial cable 16 is provided between the inlet capillary tube 9 and the outlet capillary tube 10. Part of the coaxial cable 16 is inside the catheter body and part is inside the water tank 18. Specifically, the two ends of the coaxial cable 16 are connected to the catheter needle 5 and the microwave ablation connector 15, respectively. During the operation, the microwave ablation connector 15 is connected to the external microwave ablation device to provide microwave energy to the catheter needle 5.

[0036] Both the inlet capillary tube 9 and the outlet capillary tube 10 are connected to a water pipe Luer connector 14, which can be connected to an external water inlet / outlet device. The water tank 18 is equipped with a thermistor 13, which can detect the temperature at the distal end of the conduit and at the conduit needle 5 in real time.

[0037] When the ablation catheter is working normally, the external coolant enters the entire inner cavity of the catheter through the inlet capillary tube 9 and then flows out through the outlet capillary tube 10, thus forming a closed loop. The coolant is generally ice-cold physiological saline.

[0038] There is a slider 11 on the water tank 18, and a spring 12 is connected to one side of the slider 11.

[0039] The water tank 18 is connected to the rear end of the conduit body. The conduit body has multiple layers: an outer layer (outer tube 8), a middle reinforcing layer 19, and an inner lining 23 attached to the middle layer. The center is a cavity. The inlet capillary tube 9, the outlet capillary tube 10, and part of the coaxial cable 16 are all inside the cavity of the conduit body.

[0040] The intermediate reinforcing layer 19 employs an integrated thiazo tube engraving technology, where a single thiazo tube is engraved with meshes of varying densities according to flexibility requirements. This improves catheter flexibility while ensuring that the peak tensile strength meets the requirements. Simultaneously, the intermediate reinforcing layer 19 possesses good mechanical strength, providing support for the outer tube 8, inlet capillary tube 9, outlet capillary tube 10, and coaxial cable 16, ensuring that it does not kink when passing through tortuous blood vessels.

[0041] The outer tube 8 has four symmetrical inner guide wire channels 21. Four inner guide wires 7 can be inserted into the four inner guide wire channels 21 respectively. The inner guide wires 7 are inserted into the inner guide wire channels 21 from outside the handle 17. The pushing and retraction of the inner guide wires 7 can be controlled from outside the handle 17.

[0042] A draw wire channel 22 is provided between each pair of inner guide wire channels 21, for a total of four draw wire channels 22. Four draw wires 6 can be inserted into the four draw wire channels 22 respectively. The outer tube 8 has good flexibility and can follow the shape changes of the tortuous blood vessel to shuttle and move inside the blood vessel, ensuring that it will not break under repeated bending and pushing.

[0043] When the catheter passes through a tortuous blood vessel and good catheter flexibility is required, the inner guidewire 7 can be retracted, thus improving the flexibility of the distal end of the catheter. When the catheter is delivered to the designated lesion site and increased support is required, the inner guidewire 7 can be pushed forward. The inner guidewire 7 can provide support for the catheter lumen, ensuring normal flow of water in and out of the capillary. The entire operation process only requires pushing or retracting the inner guidewire 7 to switch between catheter flexibility and support.

[0044] One end of the wire 6 is connected to the rear end of the protective umbrella 2, and the other end of the wire 6 is connected to the slider 11.

[0045] The front end of the intermediate reinforcing layer 19 is connected to the second radiopaque ring 20, which is located inside the catheter body.

[0046] The developing ring 20 is located between the inlet and outlet capillaries (inlet capillary 9 and outlet capillary 10) and the catheter needle 5.

[0047] The front end of the catheter body is connected to the catheter needle 5, the front end of the catheter needle 5 is connected to the guide wire 4, the guide wire 4 has a sliding shaft 3, and the sliding shaft 3 is connected to the mesh wire of the protective umbrella 2.

[0048] When the protective umbrella 2 is working, slide the slider 11 forward to open the protective umbrella 2. After releasing the slider 11, the slider 11 pulls the wire 6 under the pulling force of the spring 12 to close the protective umbrella 2. The smooth retraction of the protective umbrella 2 also requires the sliding shaft 3 to pull the mesh wire of the protective umbrella. The sliding shaft 3 can slide back and forth on the guide wire 4.

[0049] The front end of the protective umbrella 2 is connected to the developing ring 1, and the developing ring 1 and the front end of the protective umbrella 2 are fixed on the guide wire 4. The developing ring 1, the front end of the protective umbrella 2, and the slide shaft 3 are all on the guide wire 4, arranged in order of distance from the handle 17, with the developing ring 1 being the furthest, followed by the front end of the protective umbrella 2 and the slide shaft 3.

[0050] When the thrombus melts and breaks off, it can drift with the blood flow into the protective umbrella 2. The imaging ring 1 at the front end of the protective umbrella 2 can accurately locate the specific position of the thrombus.

[0051] The working process of microwave ablation of thrombus catheters is as follows: The microwave ablation thrombus catheter of the present invention utilizes microwave energy to remove thrombi. Under DSA (digital subtraction angiography) angiography, the microwave ablation thrombus catheter can accurately locate the thrombus lesion through the contrast ring 1 and contrast ring 20 at the distal end of the catheter. The catheter needle 5 is then delivered to the thrombus lesion site. The slider 11 of the drive handle 17 opens the protective umbrella 2, connecting the catheter handle 17 to an external microwave ablation device. The coaxial cable 16 transfers microwave energy to the catheter needle 5 at the distal end of the catheter. As the catheter needle 5 receives microwave energy, it spontaneously heats up, thereby melting the thrombus through microwave energy and cooling it through capillary cooling, thus melting and detaching the stubborn thrombus, achieving the effect of thrombus removal.

[0052] More specifically, when the slide shaft 3 slides forward, it pushes or tightens the mesh of the protective umbrella 2, keeping the opening of the protective umbrella 2 open; when the pull wire 6 pulls backward to close the protective umbrella 2, the slide shaft 3 slides backward accordingly, and the mesh of the protective umbrella 2 slides on the slide shaft 3, like a pulley system, thereby orderly gathering the umbrella net of the protective umbrella 2 into a bundle, preventing tangling and ensuring that thrombi can be captured.

[0053] The external microwave ablation device acts as a microwave energy source. During operation, the coaxial cable 16 emits microwaves to the catheter needle 5, forming a radiation zone. This causes the polar molecules in the tissue within the radiation zone to rotate and vibrate, generating a thermal effect. This heat inactivates the sympathetic nerves within the radiation zone. During this process, the capillaries (inlet capillary 9 and outlet capillary 10) inside the catheter lumen in the radiation zone continuously circulate coolant, cooling the tip or front end of the catheter and ensuring that the ablation temperature in the radiation zone meets the safe ablation temperature. The thermistor 13 inside the microwave ablation catheter can monitor temperature changes in real time on the water tank 18.

[0054] Example 2 Based on Example 1, the outer tube 8, the inlet capillary tube 9, and the outlet capillary tube 10 are all hollow tubes made of PEEK material. PEEK material is a polymer material with good mechanical properties, and it is resistant to high temperature, impact, acid and alkali, wear, fatigue, radiation, and has good electrical properties. The selection of this material can ensure that the tube body and capillary tubes (inlet capillary tube 9 and outlet capillary tube 10) at the needle tip 5 of the catheter can withstand the heat impact generated by the high temperature during microwave ablation.

[0055] Example 3 Based on Example 1 or Example 2, the catheter needle 5 is an SUS304 needle, and the surface of the catheter needle 5 is coated with a PTFE coating. When the catheter is working, when microwave heat is transferred to the catheter needle 55, the PTFE coating can prevent the catheter needle 5 from sticking to the blood vessel wall or other tissues, thereby improving the ablation effect and ablation efficiency.

[0056] The specific steps for preparing a PTFE coating are as follows: Raw materials used: Etching solution: Sodium naphthalene, which can be purchased from Fangzhou (Fogang) Chemical Materials Co., Ltd. as AC-711 sodium naphthalene PTFE etching solution.

[0057] PTFE dispersion: 60% solids content, grade available: DuPont Teflon® PTFE DISP 30.

[0058] 1. Pretreatment: Clean the catheter needle 5 sequentially with acetone, ethanol and deionized water using ultrasonic cleaning for 10 minutes each.

[0059] Then immerse the surface in the etching solution for 5-10 seconds to activate it.

[0060] After removal, rinse thoroughly and air dry or nitrogen blow dry to obtain the pretreated catheter needle 5.

[0061] 2. Take the PTFE dispersion and dilute it with deionized water to a working concentration of 10% to form a coating solution.

[0062] 3. Immerse the pretreated catheter needle 5 in a sufficient amount of coating liquid and let it stand for 1 minute; slowly pull out the needle, controlling the pulling speed to about 1 mm / s, and maintain a uniform coating; pre-dry at room temperature for 10 minutes, and then dry in an 80℃ oven for 30 minutes; transfer the dried catheter needle 5 into a high-temperature sintering furnace, heat it to 375℃ at a heating rate of 5℃ / min in an air atmosphere, and hold it at that temperature for 20-30 minutes, then cool it to room temperature to complete the coating.

[0063] Example 4 Based on Example 1, Example 2 or Example 3, the inner liner 24 is a PTFE membrane.

[0064] Example 5 Based on Example 1, Example 2 or Example 4, the catheter needle 5 is an SUS304 needle, and the surface of the catheter needle 5 is coated with a lubricating coating.

[0065] The specific steps for preparing the lubricating coating are as follows: Raw materials used: Propyltriethoxysilane isocyanate: IPTS; Hydroxyl-terminated polydimethylsiloxane: PDMS-OH; Ionic liquid: 1-Ethyl-3-methylimidazolium dihydrogen phosphate; 1. Pretreatment: Clean the catheter needle 5 sequentially with ethanol and deionized water using ultrasonic cleaning for 5 minutes each.

[0066] Then immerse in 1% NaOH solution for 2 minutes to activate the surface.

[0067] Rinse thoroughly, air dry or blow dry with nitrogen, then soak the needle in an ethanol solution containing 1% IPTS for 5 minutes, let it stand to dry, forming an active silane layer, to obtain the pretreated catheter needle 5.

[0068] 2. Weigh 2g of PDMS-OH and add it to 8mL of ethanol and stir well; add 0.2g of ionic liquid, stir, and sonicate for 10 minutes to form a coating solution.

[0069] 3. Immerse the pretreated catheter needle 5 into the coating solution and let it stand for 1 minute; slowly pull out the needle, controlling the pulling speed to about 1 mm / s, and maintain a uniform coating; pre-dry at room temperature for 5 minutes, then place it in a 60℃ oven and heat for 30 minutes; allow it to cool naturally to complete the coating.

[0070] Example 6 In Example 1, "the intermediate reinforcing layer 19 adopts an integrated hyaluronic acid tube engraving technology, that is, a hyaluronic acid tube is engraved with meshes of different densities according to the requirements of flexibility, which improves the flexibility of the tube while ensuring that the peak tensile strength meets the requirements." More specific settings are as follows: Distal segment of catheter: The first 50mm has high engraving density, an opening rate of 30-40%, and small and evenly distributed pores, which can enhance flexibility and adapt to the curvature of blood vessels; Middle section of the conduit: 50-100mm, with medium engraving density and an opening rate of 20-30%, which can balance flexibility and support; The section of the conduit near the handle: after 100mm, low density or no carving, with an opening rate of <10%, can maintain the overall tensile strength and force transmission capacity.

[0071] In the above, the engraved pattern consists of circular holes arranged in a spiral offset to avoid stress concentration.

[0072] To verify the performance of catheter needles 5 with different coatings in a microwave environment.

[0073] Materials used: Catheter needle 5 sample: coated catheter needle 5 of Examples 3 and 5.

[0074] Simulated blood vessels / artificial blood vessels: polyurethane blood vessel model.

[0075] PBS: Phosphate-buffered saline solution.

[0076] Testing process: The catheter needle samples were preheated to 37°C, and the vascular model was pre-wetted in PBS.

[0077] Equipment setup: Place the tip of catheter needle 5 in contact with the simulated blood vessel wall and set a friction path of 5cm.

[0078] Sliding test: Pull out the catheter needle 5 at a constant speed of 2 mm / s and record the maximum sliding friction force (peak N).

[0079] Repeated testing: Each sample was tested 3 times, and the average value and error were recorded.

[0080] The results were as follows: the maximum sliding friction force in Example 3 was 1.85 N; the maximum sliding friction force in Example 5 was 0.92 N.

[0081] Analysis: The PTFE coating in Example 3 can prevent the catheter tip 5 from adhering to the blood vessel wall or other tissues, thereby improving the ablation effect and ablation efficiency.

[0082] However, compared with Example 3, Example 5 has a lower frictional resistance in its coating. In a clinical simulation environment, Example 5 can better ensure the smoothness and safety of the catheter needle 5 during insertion and withdrawal, and reduces the risk of vascular damage that may be caused by adhesion or dragging.

[0083] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A microwave ablation catheter for thrombi, characterized in that, Includes a handle, which contains a water tank. The front end of the water tank is connected to the main body of the conduit, and the rear end of the water tank is connected to a microwave ablation connector. The water tank is externally inserted into the inlet capillary and the outlet capillary. A coaxial cable is provided between the inlet capillary and the outlet capillary. Part of the coaxial cable is inside the main body of the conduit, and part of it is inside the water tank. The water tank has a slider connected to a spring. The conduit body has multiple layers: an outer tube, a middle reinforcing layer, an inner liner, and a central cavity. The inlet capillary tube, outlet capillary tube, and part of the coaxial cable are all located inside the cavity of the conduit body. The outer tube has multiple symmetrical inner lining guide wire channels, each of which inserts an inner lining guide wire. A drawing wire channel is provided between the inner lining guide wire channels, through which a drawing wire is inserted. One end of the drawing wire is connected to the rear end of the protective umbrella, and the other end of the drawing wire is connected to a slider. The front end of the intermediate reinforcing layer is connected to the second imaging ring, the front end of the catheter body is connected to the catheter needle, the front end of the catheter needle is connected to the guidewire, the guidewire has a sliding shaft, the sliding shaft is connected to the mesh wire of the protective umbrella, and the front end of the protective umbrella is connected to the first imaging ring.

2. The microwave ablation thrombus catheter according to claim 1, characterized in that, The inlet capillary tube and the outlet capillary tube pass through the water tank and into the main body of the conduit.

3. The microwave ablation thrombus catheter according to claim 1, characterized in that, The two ends of the coaxial cable are connected to the catheter needle and the microwave ablation connector, respectively. The microwave ablation connector is connected to an external microwave ablation device to provide microwave energy to the catheter needle.

4. The microwave ablation thrombus catheter according to claim 1, characterized in that, Both the inlet and outlet capillary tubes are connected to water pipe Luer connectors, which in turn connect to external inlet and outlet water devices.

5. The microwave ablation thrombus catheter according to claim 1, characterized in that, The water tank is equipped with a thermistor; the inner lining is a PTFE membrane, and the outer tube, inlet capillary tube, and outlet capillary tube are all hollow tubes made of PEEK material.

6. The microwave ablation thrombus catheter according to claim 1, characterized in that, The inner guidewire is inserted into the inner guidewire cavity from outside the handle, and the pushing and retraction of the inner guidewire can be controlled from outside the handle.

7. The microwave ablation thrombus catheter according to claim 1, characterized in that, The second imaging ring is located inside the main body of the catheter. The front side of the second imaging ring is the catheter needle, and the rear side is the inlet capillary and the outlet capillary.

8. The microwave ablation thrombus catheter according to claim 1, characterized in that, The front end of the protective umbrella is connected to the developing ring 1. The developing ring 1 and the front end of the protective umbrella are fixed on the guide wire. The developing ring 1, the front end of the protective umbrella, and the sliding shaft are all on the guide wire, arranged in order of distance from the handle. The farthest one is the developing ring 1, followed by the front end of the protective umbrella and the sliding shaft.

9. The microwave ablation thrombus catheter according to claim 1, characterized in that, The catheter needle is made of SUS304 and has a PTFE coating on its surface.

10. The microwave ablation thrombus catheter according to claim 1, characterized in that, The catheter needle is made of SUS304 stainless steel, and the surface of the catheter needle is coated with a lubricating coating. The preparation method of the lubricating coating includes the following steps: The catheter needle was immersed in NaOH solution for activation, rinsed clean, dried, immersed in ethanol solution containing IPTS, and then dried to obtain the pretreated catheter needle. PDMS-OH was added to ethanol and stirred until homogeneous; then an ionic liquid was added, stirred, and sonicated to form a coating solution. Immerse the pretreated catheter needle in the coating solution and let it stand; slowly pull out the needle and let it dry to form a lubricating coating on the surface of the catheter needle. Among them, the ionic liquid includes 1-ethyl-3-methylimidazolium dihydrogen phosphate.

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