Rapidly vaporized varicosity ablation catheter

Abstract

The rapid vaporization varicosity ablation catheter comprises a needle head, a needle rod and a handle, and the needle rod comprises an outer sleeve and a coaxial cable; the needle head comprises a catheter head end located at the far end, a first insulation lining, a first metal clamping sleeve, a second insulation lining and a second metal clamping sleeve are sequentially arranged between the catheter head end and the outer sleeve, and the coaxial cable extends to the catheter head end from the outer sleeve. A shielding layer of the coaxial cable is provided with exposed windows corresponding to the first insulating bush and the second insulating bush, and a thermocouple wire is arranged between the second insulating bush and the second metal clamping sleeve; and the thermocouple wire is connected to a temperature measuring head at the handle through a transmission line. According to the invention, the risk of excessive ablation or damage to normal tissues can be avoided, and the operation efficiency and the operation safety are improved.

Description

Technical Field

[0001] The present invention relates to a varicose vein ablation catheter with rapid vaporization, belonging to the technical field of medical devices. Background Art

[0002] Varicose veins refer to the process in which veins bulge and the continuous venous valves lose their function. When treating varicose veins with an existing ordinary microwave ablation catheter, the microwave ablation catheter is inserted into the treatment site of the patient, and the microwave radiation antenna at the front end of the microwave ablation catheter radiates microwave energy in all directions. The diseased tissue receives the microwave energy and generates heat by itself. When the tissue temperature reaches above 60°C, the tissue dehydrates, coagulates, and protein denatures, causing the blood vessel wall to contract and thus closing the blood vessel lumen.

[0003] The morphological distribution characteristics of varicose vein diseased tissue are very long along the axial direction of the vein blood vessel and very small in the radial direction. To avoid the situation that the rod temperature is too high and easily burns healthy human tissue, and to protect the catheter from damage, the microwave ablation catheter adopts an intermittent retraction operation. It starts to coagulate from the distal end, closes a section and then retracts the ablation catheter and coagulates again. It retracts 1 cm each time and cycles like this. Not only is the operation limited, but the operation time is also relatively long. And currently, it is necessary to confirm the fibrosis of the treated blood vessel through the image of ultrasound. The real-time temperature of blood vessel closure cannot be known, and the ultrasonic feedback of some deep veins is relatively delayed, there are certain application risks, and it is easy to form excessive ablation of the vein wall. Summary of the Invention

[0004] The purpose of the present invention is to provide a varicose vein ablation catheter with rapid vaporization that can avoid the risk of excessive ablation or damage to normal tissue, and can improve the surgical efficiency and operation safety.

[0005] To achieve the above purpose, the present invention provides a varicose vein ablation catheter with rapid vaporization, which includes a needle head, a needle rod and a handle. The needle rod includes an outer sleeve and a coaxial cable; The needle head includes a catheter head end at the distal end. Between the catheter head end and the outer sleeve, there are successively arranged a first insulating bushing, a first metal ferrule, a second insulating bushing and a second metal ferrule. The coaxial cable extends from the outer sleeve to the catheter head end. The coaxial cable includes three layers: an inner conductor, a shielding layer and an outer conductor. The catheter head end is electrically connected to the inner conductor of the coaxial cable. The first metal ferrule and the second metal ferrule are electrically connected to the outer conductor of the coaxial cable. The second metal ferrule is clamped and connected to the outer sleeve; the shielding layer of the coaxial cable is provided with exposed windows corresponding to the first insulating bushing and the second insulating bushing. A thermocouple wire is installed between the second insulating bushing and the second metal ferrule; the thermocouple wire is connected to the temperature measuring head at the handle through a transmission line; The handle is provided with a microwave connector connected to a coaxial cable, a temperature measurement connector connected to the head end of a thermocouple through a thermocouple wire, and a cold circulation water tank. A cooling capillary tube communicating with the cold circulation water tank is arranged in the needle rod, and a water blocking ring is arranged between the second metal ferrule and the coaxial cable.

[0006] According to the clinical pain points, the present invention provides a cold circulation varicose vein ablation catheter with two-point ablation and dual-channel temperature measurement. By two-point ablation, the ablation long diameter is increased, thereby reducing the treatment time and improving the treatment efficiency. With the cold circulation function, the rod temperature can be effectively controlled, normal tissues can be protected from being scalded, continuous ablation operation can be realized without damaging the catheter, and with the dual-channel temperature measurement function, the central temperature and the rod temperature can be detected in real time, adding a double insurance for evaluating the blood vessel closure effect and treatment safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0008] Figure 2 It is a schematic front-end structure diagram of a microwave ablation catheter.

[0009] Figure 3 It is a schematic diagram of a coaxial cable.

[0010] Figure 4 It is a schematic diagram of a handle.

[0011] Reference numerals: 1, needle tip; 2, needle rod; 3, handle; 10, catheter head end; 11-a, first insulating bushing; 11-b, second insulating bushing; 12-a, first metal ferrule; 12-b, second metal ferrule; 13, coaxial cable; 13-1, inner conductor; 13-2a, shielding layer 1; 13-2b, shielding layer 2; 13-3a, outer conductor 1; 13-3b, outer conductor 2; 14, thermocouple head end; 15, thermocouple wire; 16, water blocking ring; 20, cooling capillary tube; 21, outer sleeve; 22, water tank bushing; 23, water blocking bushing; 24, return water tank; 25, water inlet tank; 26, water inlet; 27, water return port; 28, microwave connector; 29, thermistor; 31, water inlet pipe; 32, water return pipe; 33, microwave cable; 34, microwave connection head; 35, transmission line; 36, temperature measurement connection head. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0012] Microwave has the advantages of high thermal efficiency, fast heating rate, and uniform thermal field. Microwave treatment in the vein cavity is to directly act a microwave ablation catheter on the blood vessel wall of the vein cavity. The ablation catheter uses a radiation window to emit microwave energy, making it instantaneously generate a certain penetrating high temperature in a small range to coagulate tissues, and then making the tissue of the vein wall of the blood vessel cavity denature and contract, gradually fibrosis, and finally completely close, so as to achieve the treatment purpose.

[0013] This embodiment relates to a varicose vein ablation catheter with rapid vaporization, as Figures 1 - 4 shown, which includes a needle 1, a needle rod 2 and a handle 3. The needle rod 2 includes an outer sleeve 21 and a coaxial cable 13. According to the different lengths of the lower limbs of clinical patients, the length of the ablation catheter exposed outside the handle 3 is 800 - 1200 mm. The part of the catheter in contact with the human body is made of PTFE with good biocompatibility and SUS304 sprayed with Teflon.

[0014] The needle 1 includes a catheter head end 10 at the distal end. Between the catheter head end 10 and the outer sleeve 21, there are successively arranged a first insulating bushing 11-a, a first metal ferrule 12-a, a second insulating bushing 11-b and a second metal ferrule 12-b. The coaxial cable 13 extends from the outer sleeve 21 to the catheter head end 10. The coaxial cable 13 includes three layers: an inner conductor 13-1, a shielding layer and an outer conductor. The catheter head end 10 is electrically connected to the inner conductor 13-1 of the coaxial cable 13. The first metal ferrule 12-a and the second metal ferrule 12-b are electrically connected to the outer conductor of the coaxial cable 13. The second metal ferrule 12-b is clamped and connected to the outer sleeve 21. The shielding layer of the coaxial cable 13 is provided with exposed windows corresponding to the first insulating bushing 11-a and the second insulating bushing 11-b. A thermocouple wire 15 is installed between the second insulating bushing 11-b and the second metal ferrule 12-b. The thermocouple wire 15 is connected to a temperature measuring head at the handle 3 through a transmission line 35. Figures 1 - 3 As shown in, the directions from left to right are successively defined as the distal end and the proximal end.

[0015] The handle 3 is provided with a microwave connector 28 connected to the coaxial cable 13, a temperature measuring connector 36 connected to the thermocouple head end 14 through the thermocouple wire 15, and a cold circulation water tank. A cooling capillary 20 communicating with the cold circulation water tank is arranged in the needle rod 2. A water blocking ring 16 is arranged between the second metal ferrule 12-b and the coaxial cable 13. Through the above settings, it is ensured that the cold circulation water only cools the temperature of the needle rod 2, ensuring the accuracy of the central temperature. The needle rod 2 is provided with scales to display the insertion depth.

[0016] The catheter head end 10 and the inner conductor 13-1 of the coaxial cable 13 are tightly connected by crimping or welding. The first and second insulating ferrule parts are made of polytetrafluoroethylene material or polymer material with good insulation performance and high temperature resistance, forming two radiation windows for energy radiation, forming two-point ablation, increasing the ablation major axis, and thus improving the treatment efficiency.

[0017] The cold circulation water tank includes a water inlet tank and a water return tank separated by a water blocking bushing, and is respectively connected to a cold circulation water inlet and a water return port arranged on the handle. The water blocking bushing is provided with a thermistor for monitoring the temperature of the needle rod.

[0018] AsFigure 3 Inside the ablation catheter needle rod 2 shown, there are also a cooling capillary 20, an outer sleeve 21, a water tank bushing 22, a water blocking bushing 23, a cold circulation return water tank 24, a cold circulation inlet water tank 25, a cold circulation water inlet 26, a cold circulation water return port 27, a microwave connector 28, and a thermistor 29. One end of the outer sleeve 21 is tightly connected to the barbs of the second metal ferrule 12-b, and the other end is tightly connected to the barbs of the water tank bushing 22. The channel between the coaxial cable 13 and the cooling capillary 20 is the water inlet cavity. The distance between the cooling capillary 20 and the water blocking ring 16 is controlled within 2 - 5 mm to ensure that the cooling water flows smoothly into the return water cavity. The channel between the cooling capillary 20 and the outer sleeve 21 is the return water cavity. The water blocking ring 16 at the tail of the second metal ferrule 12-b is tightly connected to the coaxial cable 13 to ensure that the cold circulating water only cools the temperature of the needle rod, guarantee the accuracy of central temperature monitoring, realize continuous operation, and improve the service life of the catheter. The water blocking bushing 23 separates the cold circulation return water tank 24 and the cold circulation inlet water tank 25. The cold circulation return water tank 24 is provided with a cold circulation water return port 27, and the cold circulation inlet water tank 25 is provided with a cold circulation water inlet 26. The thermistor 29 is fixed on the water tank bushing 22 to monitor the temperature of the cold circulation rod in real time. The thermocouple wire 15 is in the return water cavity channel.

[0019] As Figure 3 、 Figure 4 shown, the handle 3 includes a cold circulation inlet water pipe 31, a cold circulation return water pipe 32, a microwave cable 33, a microwave connector 34, a transmission line 35, and a temperature measurement connector 36. The cold circulation inlet water pipe 31 is adhesively connected to the cold circulation water inlet 26, and the cold circulation return water pipe 32 is adhesively connected to the cold circulation water return port 27. The microwave connector 28 is connected to the microwave connector 34 through the microwave cable 33 to achieve microwave transmission. The thermocouple wire 15 and the thermistor 29 are connected to the temperature measurement connector 36 through the transmission line 35. The transmission line 35 is a multi-core wire with an electromagnetic shielding rate ≥ 90%, and the temperature measurement connector 36 is a corresponding multi-core plug. This embodiment can also be improved as follows: 1) A display module for real-time displaying the temperatures measured by the thermocouple head end and the thermistor is provided on the handle, and a warning is issued when the displayed temperature exceeds the expected set temperature.

[0020] 2) The distance L between the catheter head end and the metal ferrule is an integer multiple of the microwave wavelength.

[0021] 3) The transmission line is a multi-core wire with an electromagnetic shielding rate ≥ 90%, and the temperature measurement connector is a corresponding multi-core plug.

Claims

1. A rapid vaporization varicose vein ablation catheter, comprising a needle tip, a needle shaft and a handle, characterized in that: The needle rod includes an outer sleeve and a coaxial cable; The needle head includes a catheter head end at the distal end. Between the catheter head end and the outer sleeve, there are successively arranged a first insulating bushing, a first metal ferrule, a second insulating bushing, and a second metal ferrule. The coaxial cable extends from the outer sleeve to the catheter head end. The coaxial cable includes three layers: an inner conductor, a shielding layer, and an outer conductor. The catheter head end is electrically connected to the inner conductor of the coaxial cable. The first metal ferrule and the second metal ferrule are electrically connected to the outer conductor of the coaxial cable. The second metal ferrule is clamped and connected to the outer sleeve. The shielding layer of the coaxial cable is provided with exposed windows corresponding to the first insulating bushing and the second insulating bushing. A thermocouple wire is installed between the second insulating bushing and the second metal ferrule. The thermocouple wire is connected to a temperature measuring head at the handle through a transmission line; The handle is provided with a microwave connector connected to the coaxial cable, a temperature measuring connector connected to the head end of the thermocouple through the thermocouple wire, and a cold circulation water tank. A cooling capillary tube communicating with the cold circulation water tank is arranged in the needle rod. A water blocking ring is arranged between the second metal ferrule and the coaxial cable.

2. The rapidly vaporizing varicose vein ablation catheter according to claim 1, characterized in that: The cold circulation water tank includes a water inlet tank and a water return tank separated by a water blocking bushing, and is respectively connected to a cold circulation water inlet and a water return port arranged on the handle. The water blocking bushing is provided with a thermistor for monitoring the temperature of the needle rod.

3. The rapid vaporization varicose vein ablation catheter according to claim 2, characterized in that: The handle is provided with a display module for real-time displaying the temperatures measured by the head end of the thermocouple and the thermistor, and issues a warning when the displayed temperature exceeds the expected set temperature.

4. The rapidly vaporizing varicose vein ablation catheter according to any one of claims 1-3, characterized in that: The distance L between the catheter head end and the metal ferrule is an integer multiple of the microwave wavelength.

5. The rapid vaporization varicose vein ablation catheter according to claim 1, wherein: The transmission line is a multi-core wire with an electromagnetic shielding rate ≥ 90%, and the temperature measuring connector is a corresponding multi-core plug.

6. The rapid vaporization varicose vein ablation catheter according to claim 1, characterized in that: The needle rod is provided with scales.

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