Thermal ablation catheter with thermocouple and thermal ablation device

Abstract

The present disclosure provides a thermal ablation catheter with a thermocouple, comprising: a thermocouple temperature measuring end, which is in a sandwich structure, including a first electrode, a second electrode and a sandwich weld, wherein the free ends of the first electrode and the second electrode face oppositely and are parallel to each other and close to each other, and are conductively connected through the sandwich weld; a liner, which is a hollow structure for accommodating a thermal ablation component, and the thermocouple temperature measuring end is arranged on the outer circumferential surface of the liner; a heating resistance wire, which is wound around the outer circumference of the liner in a helical shape; wherein the thermocouple temperature measuring end is arranged on the liner between two adjacent turns of the heating resistance wire, the outer surface of the thermocouple temperature measuring end and the outer surface of the heating resistance wire are on the same circumferential surface, the first electrode, the second electrode and the heating resistance wire are arranged in parallel, the thermocouple temperature measuring end is centrally symmetrical, and the first electrode and the adjacent thermal resistance wires, the second electrode and the adjacent thermal resistance wires are centrally symmetrical about the center point of the thermocouple temperature measuring end.

Description

Technical Field

[0001] The present disclosure relates to the field of minimally invasive medical devices, and in particular to a thermal ablation catheter and a thermal ablation device with a thermocouple. Background Art

[0002] Minimally invasive treatment, the most common thermal ablation, is less invasive than traditional open surgery, with less pain, lower complication rate, faster recovery, and shorter downtime. It has gradually become the main surgery in the treatment of heart diseases such as saphenous vein insufficiency in the lower limbs, atrial fibrillation caused by abnormal myocardial signal conduction, refractory hypertension, vascular obstruction, and intracavitary tumors of the esophagus and cervix. Among them, for lower limb saphenous vein insufficiency, a disease that affects about 26% of adults, since the late 1990s, the application of intravenous thermal ablation for varicose veins, namely radiofrequency ablation (RFA) and intravenous laser ablation (EVLA), has developed rapidly, and its effectiveness and safety have been fully demonstrated in many studies. Although its price is more expensive than open surgery (disposable catheter is about 10,000 yuan, and the operation fee is about 1,000 yuan), considering comprehensive factors such as resumption of work time, bed resources, and patient quality of life, intravenous thermal ablation has become the preferred method for treating saphenous vein insufficiency in the guidelines for the treatment of varicose veins of the lower limbs. In some countries, the rate of intravenous thermal ablation in varicose vein treatment surgery has exceeded 80%. In China, with the development of economy and science and technology, minimally invasive treatment technology has received more and more attention in the past decade. However, in the operation for treating varicose veins, the proportion of intravenous thermal ablation is less than 20% (more than 80% are traditional open operations). A fundamental factor is the high price of ablation catheters. There are three main factors that cause the high price: 1. This technology has high scientific and technological content. At present, its technology and products are only mastered by one or two manufacturers, and the price is monopolized; 2. The catheter is a delicate small mechanism, and its manufacturing process is complex or difficult; 3. Certain types of thermal ablation (such as direct radiofrequency (RF) ablation using a dual-electrode or single-electrode design, and laser ablation) require high operating experience of the doctor and a long learning curve for the doctor.

[0003] There are three key points in the design of thermal ablation catheters: 1. The feasibility of structural design and manufacturing process within a small tube size range such as 4Fr-7Fr; 2. Accurate measurement and control of the degree of ablation; 3. Biocompatibility of the outer surface of the catheter.

[0004] For key point 1: When a catheter needs to be inserted into a blood vessel or other small lumen, such as a catheter with a diameter in the range of 4Fr-7Fr, the space scale is limited, and the structural design and implementation process of the thermal ablation component and sensor are relatively difficult. One type of indirect RF ablation type catheter, its heating component uses a resistance wire (or a resistor sheet) to wind a section of the solenoid resistor, and applies a 300kHz-500kHz RF field to it. The resistor generates heat and then indirectly transfers it to the human tissue. This type of indirect RF ablation catheter usually uses a thermocouple sensor to control the ablation process. The design of this type of catheter, on the one hand, has high requirements for the size of the thermocouple temperature measuring end (or point) and the consistency between products, and requires the thermocouple temperature measuring end to be small in size and fast in response speed, and to be able to measure the actual temperature of the catheter in real time; on the other hand, the position layout of the thermocouple temperature measuring end on the catheter is also very important, which must be able to reflect the actual temperature of the outer surface of the catheter / (the surface of the ablated tissue) without affecting the uniformity of the catheter surface. For example, some existing technical solutions use traditional thermocouples, which are designed to melt the electrode tips of two different materials in parallel to form a weld. In order to ensure that the weld is small in size, The wire diameters of the two electrodes need to be very thin, which makes the processing difficult, resulting in expensive catheters and difficulty in promoting them in low-income areas. Another existing technology design is to wrap a heating resistor wire around the fiber grating and rely on a fiber grating sensor to measure the temperature and stress strain during the ablation process. Although this design can accurately measure the temperature of the catheter surface, its manufacturing process is relatively complicated. In addition, the fiber grating is fragile and easy to break. In actual applications, such as ablating varicose veins or bifurcated renal arteries, the catheter needs to advance and retreat in tortuous blood vessels, which can easily break the fiber grating.

[0005] Regarding key point 2: For catheters that use RF to act directly on the human body, the physical principle determines that it is impossible to accurately measure the actual temperature of the ablation area by relying on 2-3 temperature sensors. Due to space limitations, it is unrealistic to configure multiple sensors. Therefore, RF direct ablation catheters generally control the degree of ablation by measuring changes in human body impedance. However, since human body impedance is affected by water content, the differences between the same part of different people and different parts of the same person are relatively large. Therefore, it is difficult to flexibly adjust the specific control impedance. Too small impedance will lead to premature termination of ablation, incomplete ablation, and residue and recurrence. Too large impedance will lead to excessive ablation or even carbonization, causing tissue to stick to the catheter and unable to continue treatment. The catheter needs to be pulled out of the lesion for cleaning, and then Treatment can only be continued after that, so this type of catheter relies on expert experience and is difficult to popularize; for EVLA, since the laser releases energy locally (local high temperature can reach over 800°C), and the coagulation depth is not deep enough, it is not easy to control ablation by temperature. Generally, power is used to control the degree of ablation, and accurate temperature cannot be obtained. There are medical risks of burns, vascular perforation, and thrombotic complications, so the ablation process requires relatively high expert experience. In addition, the protection of optical fiber for laser ablation is more troublesome. The optical fiber is easy to break or the protective catheter of the optical fiber is burned off. The broken optical fiber or the burned protective catheter remains in the human body and is difficult to be detected. Medical accidents caused by such incidents are frequent, which is also the main reason why laser ablation cannot be more widely promoted and is even gradually declining.

[0006] Regarding key point 3: For RFA catheters that use 300kHz-500kHz frequency RF field to directly act on human body impedance, whether it is a single electrode, double electrode, or multi-electrode structure design, this type of catheter is not allowed to set a smooth sheath with excellent biocompatibility on the surface of its metal electrode (due to the limitation of its physical principle, adding an insulating sheath to the electrode is equivalent to adding two capacitors between the two electrodes, and 300kHz-500kHz RF cannot pass through the capacitor); for catheters that use RF indirect ablation, or their structure is irregular, or their surface is uneven, it is difficult to achieve a uniform and smooth sheath. The two types of catheters mentioned above are easy to stick to tissues when heated. When the surface sticky tissue cannot be powered, the catheter needs to be removed from the lesion and cleared before continuing the operation; when the tissue is severely adhered or even carbonized, it is not only difficult to remove the catheter, but also easy to cause bleeding again, as well as complications such as vascular perforation. Summary of the invention

[0007] 1. Technical issues to be resolved

[0008] The present disclosure provides a thermal ablation catheter and a thermal ablation device with a thermocouple to at least partially solve the above-mentioned technical problems.

[0009] (II) Technical solution

[0010] According to one aspect of the present disclosure, there is provided a thermal ablation catheter having a thermocouple, comprising:

[0011] Thermocouple temperature measuring end, the thermocouple temperature measuring end is in a sandwich structure, including a first electrode, a second electrode and a sandwich welding point, wherein the free ends of the first electrode and the second electrode face oppositely and are parallel to each other, and the free ends of the first electrode and the second electrode are conductively connected through the sandwich welding point;

[0012] A liner tube, the liner tube is a hollow structure for accommodating the thermal ablation component, and the thermocouple temperature measuring end is arranged on the outer peripheral surface of the liner tube; and

[0013] A heating resistance wire, the heating resistance wire is wound around the outer periphery of the liner in a spiral shape;

[0014] Among them, the thermocouple temperature measuring end is arranged in the gap between two adjacent turns of heating resistance wire, the gap is a spacing of 1-3 wire diameters of the thermocouple wire, and the first electrode and the second electrode of the thermocouple temperature measuring end are arranged in parallel with their respective adjacent heating resistance wires. In addition, according to an embodiment of the present disclosure, there is at least one thermocouple lead hole on the liner between the gap between the two turns of the thermocouple wire, which is used to lead the first electrode and the second electrode from the at least one thermocouple lead hole to the inner cavity of the liner. The thermocouple temperature measuring end is centrally symmetrical, and the first electrode and the adjacent thermocouple wire, the second electrode and the adjacent thermocouple wire are centrally symmetrical about the center point of the thermocouple temperature measuring end. Such a design ensures that the measurement value of the thermocouple is equal to the actual temperature of the surface of the thermal ablation component.

[0015] According to an embodiment of the present disclosure, the outer diameters of the first electrode and the second electrode are the same as the outer diameter of the heating resistance wire, and the thickness of the sandwich weld does not exceed the radius of the first electrode and the second electrode, so that the outer surface of the thermocouple temperature measuring end and the outer surface of the heating resistance wire are on the same circumferential surface, ensuring that the surface of the catheter is uniform and smooth.

[0016] According to an embodiment of the present disclosure, the thermal ablation catheter further includes:

[0017] The sheath is arranged on the outer periphery of the heating resistance wire and the liner, and the sheath is made of a material with biocompatibility, good thermal conductivity, low friction coefficient (the friction coefficient can be in the range of 0.05-0.5) and temperature resistance greater than 140°C.

[0018] According to an embodiment of the present disclosure, the heating resistance wire is formed by bending a resistance wire at the free end of the thermal ablation catheter to form a first resistance wire lead and a second resistance wire lead, and the first resistance wire lead and the second resistance wire lead are wound side by side on the outer periphery of the liner tube to form a solenoid, and the first resistance wire lead and the second resistance wire lead are respectively connected to the positive and negative poles of the corresponding power supply, so that the current directions of adjacent first resistance wire leads and second resistance wire leads are opposite.

[0019] According to an embodiment of the present disclosure, the liner tube has at least one resistance wire lead hole for leading the first resistance wire lead and the second resistance wire lead from the at least one resistance wire lead hole to the inner cavity of the liner tube.

[0020] According to an embodiment of the present disclosure, the first resistance wire lead and the second resistance wire lead are cut off at the first resistance wire lead connection point and the second resistance wire lead connection point, respectively, and are respectively connected to non-resistive extension wires.

[0021] According to an embodiment of the present disclosure, the first electrode and the second electrode are both provided with an insulating layer on their peripheries except for the sandwich welding point.

[0022] According to an embodiment of the present disclosure, the diameter of the tube of the thermal ablation catheter is approximately between 1 mm and 2.6 mm, and the diameters of the heating resistance wire and its lead wire, the first electrode of the thermocouple, the second electrode and its lead wire are between 0.1 mm and 0.2 mm.

[0023] According to an embodiment of the present disclosure, the sandwich weld has a temperature resistance greater than 150°C.

[0024] According to another aspect of the present disclosure, there is provided a thermal ablation device, comprising:

[0025] a thermal ablation catheter as previously described, and

[0026] The host is detachably connected to the ablation catheter directly or through an operating handle, and is used to energize and control the thermal ablation component of the thermal ablation catheter.

[0027] (III) Beneficial effects

[0028] It can be seen from the above technical solutions that the thermal ablation catheter and thermal ablation device with a thermocouple disclosed in the present invention have at least one of the following beneficial effects:

[0029] (1) The thermocouple disclosed in the present invention is welded together using a sandwich structure. The two electrodes of the thermocouple and the heating resistance wire have the same diameter. The manufacturing process is simple and the mechanical strength is high, which can reduce the requirements for manufacturing materials and manufacturing processes. In addition, the design of the thermocouple and the catheter structure makes the manufacturing process relatively simple and easy to manufacture, so the cost can be effectively reduced to overcome the disadvantage of the high price of the existing catheter due to the complex manufacturing process.

[0030] (2) The structure of the thermal ablation catheter using a new type of thermocouple and heating resistor wire is uniform and has no mutations, which makes it easy to assemble a sheath with a low friction coefficient and excellent biocompatibility on the periphery, ensuring that the surface of the thermal ablation component is smooth and does not stick to human tissue during thermal ablation, thus avoiding the risk of re-bleeding and complications such as vascular perforation.

[0031] (3) The heating temperature of the thermal ablation component is uniform and gentle, and the temperature measurement is real-time and accurate, so it can achieve accurate quantitative control of the treatment process, making the operation simpler, shortening the operator's learning curve, and no longer relying on expert experience, making thermal ablation treatment technology easy to popularize and promote, and reducing surgical costs;

[0032] (4) The winding method of the thermal resistor wire and the arrangement of the thermocouple ensure that the heating resistor wire does not generate electromagnetic interference to the thermocouple, and can also effectively offset the external common-mode electromagnetic interference, making treatment measurement and control more accurate; at the same time, the winding method of the thermal resistor reduces the inductance of the heating resistor wire, making the design and control of the host simpler. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic structural diagram of a thermal ablation device with a thermocouple according to an embodiment of the present disclosure.

[0034] Figure 2 Schematic diagram of the thermocouple temperature measuring end structure of the embodiment of the present disclosure.

[0035] Figure 3 This is a schematic diagram of the structure in which the temperature measuring end of the thermocouple of the embodiment of the present disclosure is arranged in the axial cross-section of the catheter.

[0036] [Description of the main component symbols of the embodiment of the present disclosure in the accompanying drawings]

[0037] 100-thermocouple temperature measuring end, 200-catheter transmission section, 300-thermal ablation component, 400-main unit, 1-first electrode, 2-second electrode, 3-welding point, 4-insulating layer, 5-heating resistance wire, 6-liner, 7-first thermocouple lead hole, 8-second thermocouple lead hole, 9-resistance wire lead hole, 10-first resistance wire lead connection point, 11-second resistance wire lead connection point, 12-first thermocouple lead connection point, 13-second thermocouple lead connection point, 14-first thermocouple lead, 15-second thermocouple lead, 16-first resistance wire lead, 17-second resistance wire lead, 18-sheath. DETAILED DESCRIPTION

[0038] The present disclosure provides a thermal ablation catheter with a thermocouple, comprising: a thermocouple temperature measuring end, which is in a sandwich structure, including a first electrode, a second electrode and a sandwich weld, wherein the free ends of the first electrode and the second electrode face oppositely and are parallel to each other, and the free ends of the first electrode and the second electrode are conductively connected via the sandwich weld; a liner, which is a hollow structure for accommodating a thermal ablation component, and the thermocouple temperature measuring end is arranged on the outer circumferential surface of the liner; a heating resistance wire, which is wound around the outer circumference of the liner in a helical shape; wherein the thermocouple temperature measuring end is arranged on the liner between two adjacent turns of the heating resistance wire, the outer surface of the thermocouple temperature measuring end and the outer surface of the heating resistance wire are on the same circumferential surface, and the first electrode and the second electrode of the thermocouple temperature measuring end are arranged in parallel with the two adjacent turns of the heating resistance wire, and have a symmetrical layout structure.

[0039] It should be explained in advance that the distal end mentioned in the detailed implementation means the free end of the thermal ablation catheter, and the proximal end means the end of the thermal ablation catheter close to the host.

[0040] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0041] Certain embodiments of the present disclosure will be described more fully below with reference to the accompanying drawings, some but not all of which will be shown. In fact, the various embodiments of the present disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure satisfies applicable legal requirements.

[0042] In one exemplary embodiment of the present disclosure, a thermal ablation catheter having a thermocouple is provided.

[0043] Figure 1 FIG. 1 is a schematic diagram of the structure of a thermal ablation device with a thermocouple according to an embodiment of the present disclosure. Figure 1As shown, the thermal ablation catheter with a thermocouple disclosed in the present invention includes a connected thermal ablation catheter and a host 400, wherein the thermal ablation catheter includes a distal thermal ablation component 300 and a proximal catheter transmission section 200, wherein the distal end is an energy-applying thermal ablation component 300, including a liner 6, a heating resistor 5, a thermocouple, and a thermocouple temperature measuring end 100 is arranged on the surface of the thermal ablation component 300, and the proximal end is an extended shaft of the catheter, including an extended liner 6, and an extended wire of the heating resistor 5 and the thermocouple, and the thermal ablation component 300 is connected to the host 400 with energy-applying and control functions through the extended wire. The thermocouple temperature measuring end 100 is arranged on the surface of the thermal ablation component 300, and the measured value reflects the actual temperature of the surface of the ablated tissue, which can more accurately measure and control the thermal ablation treatment process, avoid the loss of surrounding normal tissue due to excessive ablation, or postoperative recurrence due to insufficient ablation, and make the treatment safer and more effective.

[0044] The various parts of the thermal ablation device with a thermocouple of this embodiment are described in detail below.

[0045] The thermal ablation component 300 is arranged at the distal end of the thermal ablation catheter. The length of the thermal ablation component 300 is approximately between 1cm and 10cm, and includes a solenoid composed of a heating resistance wire 5 evenly wound around the outer circumference of the liner and a thermocouple arranged at a suitable position between the turns of the solenoid.

[0046] In this embodiment, the heating resistance wire 5 is evenly wound on the liner 6, and the thermocouple temperature measuring end 100 is also arranged on the surface of the liner 6. The cross section of the heating resistance wire 5 is circular, and its turns are in close contact with each other. There is an insulating layer on the surface of the heating resistance wire 5 to insulate the turns from each other. The insulating layer is preferably high-temperature resistant polyimide. In some other embodiments, the turns of the heating resistance wire 5 can also be spaced apart by a certain distance, so as to increase the length of the heating part or reduce the heating density.

[0047] In this embodiment, the heating resistance wire 5 is formed by folding back a resistance wire at the distal end of the thermal ablation catheter to form a double wire, and the double wires are wound side by side to form a section of a solenoid to form a thermal ablation component 300. A resistance wire lead hole 9 is provided on the liner wall near the thermal ablation component 300, which is used to route the two electrodes side by side at the tail end of the heating resistance wire 5, namely the first resistance wire lead 16 and the second resistance wire lead 17, from the inner cavity of the liner and extend inside the catheter transmission section, and respectively connect the positive and negative poles of the host 400, so that the current directions between adjacent turns are opposite. Therefore, on the one hand, under the condition of maintaining the heating power, the inductance of the heating resistance wire 5 is reduced, making the design and control of the host 400 simpler; on the other hand, it can also offset the electromagnetic field generated by the heating resistance wire 5, and will not interfere with other electrical devices, especially the thermocouple temperature measuring end 100 of the thermocouple. In addition, the above-mentioned setting can also effectively offset the common-mode electromagnetic interference of the outside world, making the treatment measurement and control more accurate.

[0048] The thermocouple temperature measuring end 100 of the thermocouple is used to quickly measure the current treatment temperature on the surface of the thermal ablation component 300. Different from the traditional thermocouple, the thermocouple temperature measuring end 100 of the present invention is a sandwich structure.

[0049] Figure 2 FIG. 1 is a schematic diagram of the thermocouple temperature measuring end structure of the embodiment of the present disclosure. Figure 2 As shown, the tail ends of the first electrode 1 and the second electrode 2 of the thermocouple extend in opposite directions. The first electrode 1 and the second electrode 2 have an insulating layer 4 except for the head end, and the insulating layer 4 can be high-temperature resistant polyimide or the like. The head ends of the two electrodes without the insulating layer 4 are reversely parallel and close to each other to form a small parallel close section, and the two parallel close electrode sections are welded together by brazing to form a thermocouple temperature measuring end of a sandwich structure, wherein the sandwich solder can be any conductive and high-temperature resistant (above 150°C) material.

[0050] The thermocouple temperature measuring end 100 of the thermocouple is arranged on the liner between two turns of thermal resistance wire. On the one hand, the thermocouple temperature measuring end 100 and the adjacent two turns of heating resistance wire 5 are symmetrically arranged, that is, the distance between the thermocouple temperature measuring point and the two turns of heating resistance wire 5 is equal, ensuring that the measured value of the thermocouple can reflect the real temperature of the surface of the catheter thermal ablation component. The heating temperature of the thermal ablation component is uniform and mild, and the temperature measurement is accurate and real-time, so that the exact quantitative control of the treatment process can be achieved, the operation is simpler, the operator's learning curve is shortened, no longer relying on expert experience, making thermal ablation treatment technology easy to popularize and promote, and can reduce surgical costs.

[0051] On the other hand, in order to ensure that the circumference of the thermal ablation component 300 is uniform and has no sudden changes, the thermocouple temperature measuring end 100 and the turns of the heating resistance wire 5 are required to be on the same circumferential surface. In order to achieve this requirement, the diameter of the two electrodes of the thermocouple is set to be the same as the diameter of the heating resistance wire 5, the height and thickness of the sandwich solder part do not exceed the diameter of the electrode, and the sandwiched thermocouple temperature measuring end 100 is laid flat on the outer wall of the liner, forming a structure with the turns of the heating resistance wire 5 on the same circumferential surface. Two or one through holes are set on the liner wall, which are used to lead the two electrodes of the thermocouple from the through holes to the inner cavity of the liner 6 respectively, and run the wires from the inner cavity to the proximal end of the catheter.

[0052] Figure 3The thermocouple temperature measuring end 100 of the embodiment of the present disclosure is arranged in the axial cross-section structure of the catheter. As shown in Figure 3, the sandwich weld 3 welds the head ends of the first electrode 1 and the second electrode 2 together to form a small section of the thermocouple temperature measuring end 100 with a sandwich structure. The radius R2 of the first electrode 1 and the second electrode 2 of the thermocouple is roughly equal to the radius R1 of the heating resistance wire 5, and the height W of the sandwich weld 3 does not exceed the radius R2 of the thermocouple electrode. The weld 3 can be a third conductive material different from the materials of the two electrodes of the thermocouple.

[0053] Please see again Figure 3 The sandwich structure of the thermocouple temperature measuring end 100 is laid flat in the gap between two adjacent turns of thermal resistors on the outer periphery of the liner 6, and is symmetrically arranged with the two turns of heating resistor wires. The gap width is 2-3 diameters of the resistor wires, ensuring that its measured value is equal to the actual temperature of the surface of the thermal ablation component 300 (or the surface of the ablated tissue). The first thermocouple lead hole 7 and the second thermocouple lead hole 8 are arranged on the liner wall of the gap. The two electrodes of the thermocouple, the first electrode 1 and the second electrode 2, respectively enter the inner cavity of the liner 6 from these two lead holes, and are routed from the inner cavity to and extend to the catheter transmission end 200. In other embodiments, a lead hole can also be arranged on the circumference of the liner 6 opposite to the thermocouple temperature measuring end, and the first thermocouple lead hole 7 and the second thermocouple lead hole 8 can also enter the inner cavity of the liner 6 through the lead hole.

[0054] By adopting the structure and layout of the thermocouple, the thermocouple temperature measuring end 100 and the outer edge of the wire turn of the heating resistor wire 5 are on the same circumferential surface, ensuring that the outer periphery of the thermal ablation component 300 is uniform and has no sudden changes. Therefore, the sheath 18 is sleeved on the uniform outer periphery of the thermal ablation catheter, which can simplify the assembly and manufacturing process of the sheath 18 and ensure that the surface of the sheath 18 is uniform and smooth. Furthermore, the sheath 18 can preferably be made of a material with a low friction coefficient, good biocompatibility and high temperature resistance, such as FEP or PTFE, PEEK material.

[0055] The length of the proximal catheter transmission section 200 is about 50cm-100cm, and is used to transmit the thermal ablation component 300 to a certain depth or length of the lesion in the human body. The inner cavity of the liner 6 is used for routing, including the first resistance wire lead 16 and the second resistance wire lead 17 of the heating resistance wire and the first thermocouple lead 14 and the second thermocouple lead 15 of the thermocouple. In some embodiments, in order to avoid the situation that the heating resistance wire 5 is heated for a long time in the liner and the heat cannot be effectively conducted away, causing the catheter to deform or burn the liner, the two tail resistance wire lead holes 9 of the thermal resistor are cut off at the first resistance wire lead connection point 10 and the second resistance wire lead connection point 11 of the catheter transmission section 200 after entering the liner 6, and then connected to the non-resistive extended first resistance wire lead 16 and the second resistance wire lead 17 respectively. The connection point can be welding or point connection.

[0056] In some embodiments, after the electrodes of the two thermocouples enter the liner from the first thermocouple lead hole 7 and the second thermocouple lead hole 8, they are cut off at the first thermocouple lead connection point 12 and the second thermocouple lead connection point 13 of the catheter transmission section 200, and then connected to the ordinary first thermocouple lead wire 14 and the second thermocouple lead wire 15 respectively.

[0057] The first resistance wire lead 16, the second resistance wire lead 17 of the heating resistance wire 5 and the first thermocouple lead 14, the second thermocouple lead 15 of the thermocouple can be connected through the operating handle after being led out from the catheter, or directly connected to the host 400, and the host 400 applies energy and controls the treatment of the catheter thermal ablation component 300.

[0058] Specifically, the diameters of the heating resistor wire 5, the first electrode 1 of the thermocouple, the second electrode 2, the first thermocouple lead wire 14, the second thermocouple lead wire 15, the first resistor wire lead wire 16, and the second resistor wire lead wire 17 are approximately between 0.1 mm and 0.2 mm, and the body diameter of the thermal ablation catheter is approximately between 1 mm and 2.6 mm, which can pass through the existing interventional guide sheath of 5Fr-8Fr. Exemplarily, in an embodiment for renal artery ablation, the body diameter of the thermal ablation catheter is approximately between 1 mm and 1.5 mm; in an embodiment for ablation of the great saphenous vein of the lower limb, the body diameter of the thermal ablation catheter is approximately between 1.5 mm and 2.6 mm. The wall thickness of the liner tube 6 is between about 0.1 mm and 0.5 mm, and accordingly, the inner diameter of the liner tube 6 is between about 0.8 mm and 2.4 mm, so as to pass through the heating resistor wire lead wire, the thermocouple lead wire and the auxiliary tube.

[0059] The liner 6 is made of a material with good biocompatibility, flexibility, good insulation, and high temperature resistance of more than 140°C, and preferably Peek, PTFE, PI, etc. The sheath 18 is about 0.01 mm thick and is made of a material with good biocompatibility, good thermal conductivity, low friction coefficient (friction coefficient can be in the range of 0.05-0.3), and high temperature resistance of more than 140°C.

[0060] The thermal ablation device of this embodiment overcomes the disadvantages of uneven and smooth surface of the catheter thermal ablation component, inaccurate temperature measurement, complex catheter manufacturing process, and high price by adopting a new type of thermocouple structure and assembly process design, and achieves more accurate measurement and control of the thermal ablation treatment process, thereby improving the safety, effectiveness and ease of operation of the treatment.

[0061] So far, the embodiments of the present disclosure have been described in detail in conjunction with the accompanying drawings. It should be noted that the implementation methods not shown or described in the drawings or the body of the specification are all forms known to ordinary technicians in the relevant technical field and are not described in detail. In addition, the above definitions of each element and method are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and ordinary technicians in the field can simply change or replace them.

[0062] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only reference directions of the drawings and are not intended to limit the scope of protection of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure.

[0063] Moreover, the shapes and sizes of the components in the figures do not reflect the real size and proportion, but only illustrate the contents of the embodiments of the present disclosure. In addition, in the claims, any reference symbols between brackets shall not be constructed as limiting the claims.

[0064] Unless otherwise indicated, the numerical parameters in this specification and the appended claims are approximate values ​​and can vary according to the desired properties obtained through the content of the present disclosure. Specifically, all numbers used in the specification and claims to express the content of the composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. In general, the meaning of the expression is to include changes of ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments by a specific number.

[0065] Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0066] The ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., to modify the corresponding elements, do not themselves mean that the elements have any ordinal numbers, nor do they represent the order of one element and another element, or the order in the manufacturing method. The use of these ordinal numbers is only used to clearly distinguish a component with a certain name from another component with the same name.

[0067] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into multiple submodules or subunits or subcomponents. All features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination, except that at least some of such features and / or processes or units are mutually exclusive. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose. Furthermore, in a unit claim that lists several devices, several of these devices may be embodied by the same hardware item.

[0068] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the following intention: the claimed disclosure requires more features than the features explicitly recited in each claim. More specifically, as reflected in the claims below, the disclosed aspects are less than all the features of the single embodiment disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present disclosure.

[0069] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A thermal ablation catheter with a thermocouple, characterized in that: include: A thermocouple temperature measuring end (100), the thermocouple temperature measuring end (100) being in a sandwich structure, comprising a first electrode (1), a second electrode (2) and a sandwich welding point (3), wherein the free ends of the first electrode (1) and the second electrode (2) face in opposite directions and are parallel to each other and close to each other, and the free ends of the first electrode (1) and the second electrode (2) are conductively connected via the sandwich welding point (3); A liner tube (6), the liner tube (6) being a hollow structure and used for accommodating the thermal ablation component (300), the thermocouple temperature measuring end (100) being arranged on the outer peripheral surface of the liner tube (6); as well as A heating resistance wire (5), the heating resistance wire (5) being wound around the outer periphery of the liner (6) and being in the shape of a spiral tube; The thermocouple temperature measuring end (100) is arranged on the liner (6) between the gaps of two adjacent turns of the heating resistance wire (5), and the outer surface of the thermocouple temperature measuring end (100) and the outer surface of the heating resistance wire (5) are on the same circumferential surface, the first electrode (1) and the second electrode (2) of the thermocouple temperature measuring end (100) are arranged in parallel with the two adjacent turns of the heating resistance wire (5), the thermocouple temperature measuring end (100) is centrally symmetrical, and the structural layout of the first electrode (1) and its adjacent heating resistance wire (5) and the second electrode (2) and its adjacent heating resistance wire (5) on the liner is centrally symmetrical about the center point of the thermocouple temperature measuring end (100); The surface of the heating resistance wire (5) is provided with an insulating outer layer.

2. The thermal ablation catheter according to claim 1, characterized in that: The outer diameters of the first electrode (1) and the second electrode (2) are the same as the outer diameter of the heating resistance wire (5), and the thickness of the sandwich weld (3) does not exceed the radius of the first electrode (1) and the second electrode (2).

3. The thermal ablation catheter according to claim 1, characterized in that: The liner (6) has at least one thermocouple lead hole for leading the first electrode (1) and the second electrode (2) from the at least one thermocouple lead hole to the inner cavity of the liner (6), wherein the structural layout of the thermocouple lead hole of the first electrode (1) and its adjacent heating resistance wire (5) and the second electrode (2) and its adjacent heating resistance wire (5) on the liner is centrally symmetrical about the center point of the thermocouple temperature measuring end (100).

4. The thermal ablation catheter according to claim 1, characterized in that: Also includes: A sheath (18), the sheath (18) being sleeved on the outer circumference of the heating resistance wire (5) and the liner (6), the sheath (18) having a smooth surface and made of a high molecular biocompatible high temperature resistant material with a friction coefficient of 0.05-0.

3.

5. The thermal ablation catheter according to claim 4, characterized in that: The sheath (18) is made of FEP, PTFE or PEEK material.

6. The thermal ablation catheter according to claim 1, characterized in that: The heating resistance wire (5) is formed by bending a resistance wire at the free end of the thermal ablation catheter to form a first resistance wire lead (16) and a second resistance wire lead (17). The first resistance wire lead (16) and the second resistance wire lead (17) are wound side by side on the outer periphery of the liner (6) to form a solenoid. The first resistance wire lead (16) and the second resistance wire lead (17) are respectively connected to the positive and negative poles of the corresponding power supply, so that the current directions of the adjacent first resistance wire lead (16) and the second resistance wire lead (17) are opposite.

7. The thermal ablation catheter according to claim 6, characterized in that: The liner tube (6) has at least one resistance wire lead hole, which is used to lead the first resistance wire lead (16) and the second resistance wire lead (17) from the at least one resistance wire lead hole to the inner cavity of the liner tube (6).

8. The thermal ablation catheter according to claim 6, characterized in that: The first resistance wire lead (16) and the second resistance wire lead (17) are cut off at the first resistance wire lead connection point (10) and the second resistance wire lead connection point (11), respectively, and are respectively connected to non-resistive extension wires.

9. The thermal ablation catheter according to claim 1, characterized in that: The width of the gap between the two adjacent turns of the heating resistance wire (5) with the thermocouple temperature measuring end (100) arranged in the middle is 2-3 diameters of the heating resistance wire.

10. The thermal ablation catheter according to claim 1, characterized in that: The first electrode (1) and the second electrode (2), except for the sandwich welding point (3), are both provided with an insulating layer on their peripheries.

11. The thermal ablation catheter according to claim 1, characterized in that: The diameter of the tube of the thermal ablation catheter is between 1 mm and 2.6 mm, and the diameters of the heating resistance wire (5) and its lead wire, the first electrode (1) of the thermocouple, the second electrode (2) and its lead wire are between 0.1 mm and 0.2 mm.

12. The thermal ablation catheter according to claim 1, characterized in that: The sandwich solder joint (3) has a temperature resistance of 150°C.

13. A thermal ablation device, characterized in that: include: The thermal ablation catheter according to any one of claims 1 to 12, and The host (400) is detachably connected to the thermal ablation catheter directly or through an operating handle, and is used to energize and control the thermal ablation component (300) of the thermal ablation catheter.

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