CN115813542A

CN115813542A - Temperature control method of microwave ablation needle, microwave ablation needle and system

Info

Publication number: CN115813542A
Application number: CN202211599673.4A
Authority: CN
Inventors: 杨斌; 范捷; 马振禄; 任朦
Original assignee: Nanjing Yigao Medical Technology Co ltd
Current assignee: Nanjing Yigao Medical Technology Co ltd
Priority date: 2022-12-12
Filing date: 2022-12-12
Publication date: 2023-03-21

Abstract

The invention relates to a temperature control method of a microwave ablation needle, the microwave ablation needle and a system, and belongs to the technical field of microwave ablation. The method comprises the step of controlling the temperature of the choke ring by using a cooling medium, and the invention can control the temperature rising rate and reduce the occurrence of medical accidents.

Description

Temperature control method of microwave ablation needle, microwave ablation needle and system

Technical Field

The invention relates to a temperature control method of a microwave ablation needle, the microwave ablation needle and a system, and belongs to the technical field of microwave ablation.

Background

The microwave ablation has the advantages of fast temperature rise, short operation time, large ablation range and the like, and is more and more widely applied. The microwave ablation is to utilize polar molecules in human tissues to generate heat by high-speed movement and friction under the action of a microwave field, and when the temperature is raised to be higher than 60 ℃, the protein of tumor cells is denatured, solidified, dehydrated and necrotic, thereby achieving the purpose of treatment.

A microwave ablation needle generally includes a handle, a needle bar, a microwave radiator (also called a radiation antenna, etc.), a ceramic needle head, a coaxial cable, a cooling tube, etc., the handle is disposed at a rear end of the needle bar, the microwave radiator is disposed in the needle head, the coaxial cable and the cooling tube are disposed in the needle bar, and the cooling tube extends from the handle to the needle head, so that a cooling liquid can detour to a front end of the microwave radiator. The coaxial cable is used for transmitting microwave energy generated by the microwave generator to the microwave radiator so as to emit ablated microwaves, and in the process, part of the microwaves can 'escape' backwards along the outer surface of the outer conductor of the coaxial cable, so that an ablation area is in an ellipsoid shape, and the ablation range of the ablation area has large error. In order to improve the accuracy of the ablation range, inhibit the reverse escape of the microwave and obtain a round ablation zone, a choke ring (also conventionally referred to as a microwave directional ring) is often applied on the coaxial cable in the prior art, and the choke ring needs to be placed in a ceramic needle, which can be referred to the chinese patent document with the publication number of CN104688335a and the name of "a microwave ablation antenna for treating liver cancer".

Referring to the clinical application of microwave ablation technology in chapter 11 of tumor hyperthermia technology and clinical practice (author: liu Jia, press, china medical science and technology press, published time: 2009 08 month, ISBN: 9787506742559), an ablation zone is sequentially a central zone, an ablation necrosis zone and a hyperemia reaction zone from inside to outside, and the temperature of the central zone needs to be higher than 100 ℃ (usually can reach 110-120 ℃) so as to ensure that the temperature of the outer edge of the ablation necrosis zone reaches about 60 ℃. Applicants' experience has shown that when the choke ring is placed on a coaxial cable in the prior art, the temperature of the ablated central region is slowly increasing, often requiring more than 10 seconds to reach the desired temperature of the central region of greater than 100 degrees celsius.

In order to effectively cool a high-temperature area of the microwave ablation needle, cooling liquid needs to be guided to the front end of the microwave radiator through the cooling pipe, but a needle rod of the microwave ablation needle is usually thin, a choking ring is arranged on the coaxial cable to increase space occupation, and the space of the cooling pipe is occupied in a squeezing mode, so that the cooling pipe is thin, and a cooling effect is poor. The needle head is mostly made of ceramics, the temperature in the needle head can reach more than 150 ℃ under long-time work, at the moment, cracks can be generated in the needle head, and the phenomena of needle explosion and needle breakage can be seriously caused, so that medical accidents are caused.

As mentioned above, in order to ensure the cooling effect of the needle head, avoid needle explosion and needle breakage, the flow of the cooling tube needs to be ensured, so that the needle body of the ablation needle becomes thicker, the ablation needle with a thinner size cannot be manufactured, the diameter needs to be larger than 1.6mm, and the damage to the human body is larger.

In addition, the surface treatment coating process of the existing ceramic needle head is all non-metal materials (such as teflon, nano coating and the like), the materials cannot form a reflecting surface well under ultrasound, and if a metal material is adopted, microwaves emitted by a microwave radiator can be shielded, so that structural design improvement such as changing the shape of the needle head, for example, a triangular shape or designing a clamping groove on the needle head can be realized, and high-definition development cannot be realized under medical image conditions such as ultrasound.

The choking ring is arranged outside the needle head, so that the temperature of the choking ring rises too fast in the ablation process, the protective performance and the mechanical strength performance of an anti-sticking Teflon anti-coating layer on the surface layer of the ablation needle are reduced, the shedding phenomenon is generated, and the occurrence of medical accidents is reduced.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: provides a temperature control method which can control the temperature of the ablation needle to rise too fast.

In order to solve the technical problem, the first technical scheme of the invention provides a temperature control method of a microwave ablation needle, which comprises a choke ring, a cooling pipe and a microwave radiation unit, wherein the cooling pipe and the microwave radiation unit are arranged in the ablation needle, the choke ring is arranged on the outer side of a needle head, and the method comprises the step of controlling the temperature of the choke ring by using a cooling medium.

In order to solve the technical problem, the second technical solution of the present invention further provides a temperature control method for a microwave ablation needle, including a choke ring, a cooling tube and a microwave radiation unit, wherein the cooling tube and the microwave radiation unit are arranged in the ablation needle, the choke ring is arranged outside the needle head, and the method includes controlling the starting temperature of the choke ring by using a cooling medium.

In order to solve the technical problem, the third technical solution of the present invention further provides a temperature control method for a microwave ablation needle, which includes a choke ring, a cooling tube and a microwave radiation unit, wherein the cooling tube and the microwave radiation unit are arranged in the ablation needle, the choke ring is arranged outside a needle head, and the method includes adjusting the flow rate of a cooling medium in real time according to power variation or temperature variation to control the temperature of the choke ring.

On the other hand, the fourth technical scheme of the invention also provides a microwave ablation needle, which adopts the temperature control method of the first technical scheme, the second technical scheme or the third technical scheme.

On the other hand, the fifth technical scheme of the invention also provides a microwave ablation system, which comprises an ablation needle and a microwave ablation instrument, wherein a cooling pipe and a microwave radiation unit are arranged in the ablation needle, and a choke ring is arranged on the outer side of the needle head of the ablation needle;

the microwave ablator is configured to receive temperature information of the choke ring and regulate flow of the cold cutting medium within the cooling tube.

The invention has the following beneficial effects:

the invention protects the protective performance and the mechanical strength performance of the surface coating of the ablation needle by controlling the central temperature rising rate of the thermal field of the microwave ablation needle, so that the coating is not easy to fall off.

Drawings

The invention will be further explained with reference to the drawings.

Fig. 1 is a schematic view of the internal structure of the ablation needle of the invention.

Fig. 2 is a schematic illustration of the position of the choke ring and the radiating region of the coaxial cable.

Fig. 3 is a schematic view of the structure of the ablation needle of the present invention.

FIG. 4 is a graph showing the results of comparative experiments.

FIG. 5A is a graph of 80W temperature rise

FIG. 5B is a graph of temperature rise of 100W

Reference numerals are as follows: 1. a needle head; 2. a microwave radiator; 3. a coaxial cable; 4, an ablation needle; 5. a cooling tube; 6. a card slot; 7. a needle bar; 8. positioning a ring; 9. a coolant tank front cover; 10. a cooling liquid box rear sleeve; 11. a temperature measuring component; 12. a water outlet joint; 13. a water inlet joint; 14. a microwave interface; 15. a temperature measuring interface; 16. a water outlet pipe; 17. a water inlet pipe; 18. a handle; 19. a choke ring.

Detailed Description

As mentioned in the background, the cooling tube in a microwave ablation needle extends from the handle to the needle head, enabling the cooling medium to bypass to the front end of the microwave radiator. In order to improve the accuracy of the ablation range and inhibit the reverse escape of the microwave, and to obtain a rounder ablation zone, a choke ring (also conventionally referred to as a microwave directional ring) is often applied on the coaxial cable in the prior art, and the choke ring needs to be embedded in the ceramic needle. When a tumor is ablated, the central temperature of the thermal field needs to be quickly raised to radiate the periphery, when the choking ring is arranged in the needle rod, the temperature of the cooling medium at the microwave radiator needs to be raised firstly, then the heat can be quickly radiated to the periphery, and the cooling medium is used for cooling the needle rod all the time in the ablation process, so that when the choking ring is arranged in the needle rod, the central temperature of the thermal field is slowly raised, and the ablation time is prolonged. If the temperature at the center of the thermal field is increased rapidly, the temperature of the needle rod is increased if the flow rate of the cooling medium is reduced, and the temperature of normal tissues around the needle channel can be damaged. If the flow of the cooling medium is increased, the central temperature of the thermal field becomes slower, and the ablation time becomes longer.

The choke ring is arranged on the outer side of the needle head, the heat field center moves outwards at the moment, the heating speed of the choke ring is the fastest, the heat of the choke ring is quickly radiated to the periphery, and the cooling medium is not directly contacted with the choke ring, so that the heating speed of the center temperature of the whole heat field can be easily controlled by the cooling medium.

As described in the background art, the temperature of the central area of the ablation needs to be higher than 100 ℃ (usually 110-120 ℃), so that the temperature of the outer edge of the ablation necrosis area can reach about 60 ℃, and the temperature requirement of microwave ablation is met.

The applicant finds that when the microwave of the antenna is emitted, the surface of the choking ring has induced current, so that the choking ring is the region with the fastest heating, but when the choking ring is arranged inside the needle head in the prior art, when the microwave emitting antenna is actually used, the microwave emitting antenna needs to firstly heat cooling liquid inside the needle head and then conduct the heat to the periphery, but the cooling liquid takes away part of the heat generated by the choking ring during circulation, so that the central area of ablation is slowly heated.

The choke ring is arranged on the outer side of the ceramic needle head and is isolated from the cooling liquid, so that the heat generated by the choke ring is not influenced by the circulating cooling liquid any more, the temperature of the ablation central area can be quickly increased to be more than 100 ℃, the treatment time can be effectively shortened, and the life safety and effectiveness of a patient to be treated can be improved.

Set up the choke ring in the ceramic syringe needle outside, make choke ring and coolant liquid isolated back, coolant liquid is no recooling choke ring yet, therefore the inside temperature of ceramic syringe needle reduces by a wide margin, keeps being far less than 150 degrees all the time, consequently the inside crackle that can not produce because of high temperature of ceramic syringe needle has avoided the needle burst and the disconnected needle phenomenon that exist among the prior art, has reduced the emergence of medical accident.

The choke ring is arranged on the outer side of the ceramic needle head, so that the production process is simplified, the occupation of the choke ring on the space of the cooling pipe is reduced, and the microwave ablation needle with the diameter of 1.4mm or even thinner can be manufactured as required.

Set up the choke ring in the ceramic syringe needle outside, combine as a whole with the ceramic syringe needle effectively, utilize the metal material characteristic of choke ring, the better formation plane of reflection of ability under the supersound has strengthened the development of ceramic syringe needle under the supersound, consequently from the physical technology aspect, has really solved among the prior art ceramic syringe needle unobvious problem under the supersound develops.

In arranging the ceramic syringe needle of melting needle in choking ring among the prior art, the production process can't be controlled effectively, and the back is assembled to the finished product needle, can't the structure of range finding syringe needle inside, and the uniformity and the stability of ceramic syringe needle can not guarantee, lead to the temperature that generates heat of every ceramic syringe needle can not guarantee the unanimity under the same condition, therefore the electromagnetic wave of microwave emission can't accomplish accurate control. The choke ring is arranged outside the ceramic needle head, so that the assembly consistency of the choke ring can be ensured, the electromagnetic wave emitted by the microwave can be accurately controlled, and the consistency of products is ensured.

However, the too fast heating speed of the choke ring can cause the ablation needle and the choke ring to directly contact or the surrounding surface coating to fall off due to too fast heating, so the invention provides the following technical solutions.

Example one

The present embodiment relates to a method for controlling the temperature of a microwave ablation needle according to the first technical solution, as shown in fig. 1, the method comprises a choke ring 19, and a cooling tube 5 and a microwave radiation unit which are arranged in an ablation needle 4, the microwave radiation unit comprises a microwave radiator 2 and a coaxial cable 3, the choke ring 19 is arranged outside the needle head 1, and the method is to control the temperature of the choke ring 19 by using a cooling medium, so as to control the temperature rise rate of the whole thermal field. The cooling medium of the cooling tube 5 can be physiological saline, water, cooling gas and the like, and is used for preventing the interior of the needle head 1 from being overheated, and the choke ring 19 can inhibit the microwave from reversely escaping along the coaxial cable 3, so that a round ablation region (conventionally, a microwave ablation needle with a spherical ablation region is a round ablation needle) is obtained, and more accurate ablation is realized. The choke ring 19 is made of any one of copper, gold, silver, palladium, platinum, tin, nickel, zinc, and alloys thereof.

In the embodiment, the choke ring 19 is arranged outside the needle head 1 and isolated from the cooling liquid, so that the heat generated by the choke ring 19 is not influenced by the circulating cooling liquid any more, the temperature of the ablation central area can be rapidly increased, the treatment time can be effectively shortened, and the life safety and effectiveness of a patient to be treated can be improved. Applicant's experiments have shown that to increase the central temperature of the central thermal field of ablation to 110 degrees, the prior art arrangement of the choke 19 inside the ablation needle 4 is slow and, with the above-mentioned improvements, can be reduced to less than 5 seconds.

In addition, the choke ring 19 is arranged outside the needle head 1, so that after the choke ring 19 is isolated from the cooling medium, the phenomena of cracking, even needle explosion and needle breakage caused by high temperature in the needle head 1 are avoided.

The ablation needle 4 comprises a needle head 1 and a needle rod 7 which are connected in sequence, a microwave radiator 2 is arranged in the needle head 1, and a coaxial cable 3 is arranged in the needle rod 7. The needle bar 7 can be a rigid needle bar or a flexible needle bar, and the length of the needle bar 7 is generally in the range of 5-30 cm.

The microwave radiator 2, also called microwave transmitting antenna, is usually a slot antenna structure, the length of which is typically 1/4 lambda, 3/4 lambda, 5/4 lambda, 7/4 lambda, lambda being the wavelength of the microwaves emitted by the microwave radiator 2. Place the syringe needle in the microwave radiator 2 in, the microwave radiation of being convenient for, and form effectual ablation district, cooling tube 5 inserts the afterbody of microwave radiator 2, and the backward flow behind microwave radiator 2 is walked around to the coolant liquid of being convenient for, is difficult for causing rivers not smooth, ensures the low temperature of syringe needle and needle bar.

The microwave ablation needle 4 is typically provided with a handle 18 for the operator to hold and set various interfaces. As shown in fig. 3, the handle 18 is sleeved on the needle bar 7 and fixed with the needle bar 7 through the positioning ring 8, the handle 18 is of a hollow structure, and a cooling medium box and at least one cooling pipe 5, and further, two cooling pipes 5 are preferentially arranged in the handle. The cooling medium box is divided into a front cooling medium box sleeve 9 and a rear cooling medium box sleeve 10 which are in one-to-one correspondence with the two cooling pipes 5. Cooling medium case front cover 9, cooling medium case back cover 10 is equipped with

water connectors

12 and 13 respectively, microwave radiator 2 during operation, syringe needle 1 can generate heat, insert cooling medium case back cover 10 through water connectors 13, the inside cooling tube 5 of rethread, transmit cooling medium to syringe needle 1 and cool off, utilize the principle of liquid seal circulation, the heat of transmission has been taken away to the coolant liquid of syringe needle 1 department, the inside temperature of syringe needle 1 has been reduced, flow back to medium case front cover through cooling tube 5 with the medium, then take away the heat through another water connectors 12 and outlet pipe 16, form the cooling system of a backward flow. The handle is also provided with a microwave interface 14, a temperature measuring interface 15 and the like, wherein the microwave interface 14 is connected with the coaxial cable 3, transmits the microwave generated by the microwave generator to the microwave radiator 2, and emits the microwave for ablation.

The embodiment can be further modified as follows: 1) The afterbody of syringe needle 1 is equipped with draw-in groove 6, can fill glue (high temperature resistant glue) to make syringe needle 1 splice with needle bar 7 for fixed syringe needle 1 ensures that syringe needle 1 leakproofness is safe effective.

2) The thermocouple wire (not shown in the figure) is arranged on the outer side of the needle rod 7 and connected with the temperature measuring interface 15 on the handle, and is used for measuring the temperature of the needle rod 7 in real time and preventing the needle rod 7 from overheating and damaging normal tissues, and the temperature is generally required not to exceed 45 degrees.

The embodiment can be further modified as follows: the choke ring 19 has a length less than the length of the radiating area of the coaxial cable 3. The choke ring 19 is disposed at a position of 1 to 3mm in the longitudinal direction from the rear end of the transmitting antenna to the outer layer of the coaxial cable 3 of the transmitting antenna by 1 to 2mm to suppress the creeping wave of the microwave, and reference is made to "analysis and calculation of a choke groove of a coaxial rotary joint" (author: zhan Lihua, national academy of radar, china society of electronics, 1999). As shown in fig. 2, L1 is the length of the choke ring 19, L2 is the length of the radiating area of the coaxial cable 3, and the lengths of L1 and L2 are changed according to the change of the wavelength, and are divided into the cases of 1/4 λ,3/4 λ,5/4 λ,7/4 λ, etc. as required, so as to adapt to different human tissues, where λ is the wavelength of the microwave emitted by the microwave radiator 2, which is the prior art and can refer to the related documents, and the details are not repeated. In the embodiment, by setting L2> L1, more precise control of microwave field emission can be realized.

The applicant conducted a comparison experiment on the temperature control device of the present embodiment and the prior art (the difference is only that the choke ring is arranged at a different position, the present embodiment is arranged outside the needle, the prior art is arranged outside the coaxial cable inside the needle, and other parameters are substantially consistent), and performed microwave ablation on the in vitro pork liver, wherein the ablation power is 80W, and the temperature of the ablation needle 4 and the perfect roundness of the ablation region are monitored, and the result is shown in fig. 4 and briefly described as follows:

when the test time is 5 minutes, the highest temperature of the ablation center can reach 130.4 ℃, the time of reaching 70 ℃ is 3 seconds, the time of reaching 110 ℃ is 5 seconds, the ablation range (transverse diameter, long diameter and front rushing) is 36mm, 37mm and 7mm, and the roundness correction rate is 0.97 by adopting the ablation needle 4 of the embodiment; by adopting the ablation needle 4 in the prior art, the highest temperature of an ablation center can reach 114.2 ℃, the time of reaching 70 ℃ is 7 seconds, the time of reaching 110 ℃ is 12 seconds, the ablation range is 34mm, 37mm +8mm, and the roundness correction rate is 0.92.

Test time was 10 minutes: the ablation range of the ablation needle 4 adopting the embodiment is 42mm, 46mm and 10mm, the roundness correcting rate is 0.96, and the temperature of the needle rod (the temperature between the position 5cm away from the needle tip and the position between the needle tip and the handle) is less than 45 ℃; the ablation range of the ablation needle 4 adopting the prior art is 44mm + 46mm +12mm, the roundness correction rate is 0.91, and the temperature of the needle rod is less than 53 ℃. It can be seen that the ablation range is not significantly different from that before the improvement, and the temperature of the needle bar is reduced by about 8 ℃ than that before the improvement. In addition, through a plurality of experiments, when the test time of the ablation needle 4 is 15 minutes, no water leakage or needle breakage occurs.

Example two

The present embodiment relates to the second technical solution, and the method for controlling the temperature of the microwave ablation needle 4 comprises a choke ring 19, and a cooling tube 5 and a microwave radiation unit which are arranged in the ablation needle 4, wherein the microwave radiation unit comprises a microwave radiator 2 and a coaxial cable 3, the choke ring 19 is arranged outside the needle head 1, and the method comprises controlling the starting temperature of the choke ring 19 by using a cooling medium.

During the initial phase of ablation, especially at high power, if the temperature in the center of the thermal field rises too fast, the protective and mechanical strength properties of the surface coating of the ablation needle 4 will be reduced. At the beginning stage of ablation, the flow of cooling water is adjusted to a first threshold value, when the central temperature of the thermal field of the ablation needle 4 slowly rises, preheating is conducted on the ablation needle 4 in the early stage, then the flow of cooling water is rapidly adjusted to a second threshold value, and the second threshold value is smaller than the first threshold value, so that the central temperature of the thermal field of the whole tumor quickly rises. And regulating the temperature rising rate of the ablation initial stage by regulating the flow of the cooling medium.

As shown in fig. 5A and 5B, in the first 2S, the temperature rise rate of 100W is much faster than that of 80W in the ablation initiation stage.

This implementation will be more accurate regulation thermal field temperature on embodiment a technical scheme, and the protection melts the even rising of 4 whole temperatures of needle, and other the same contents are no longer repeated.

EXAMPLE III

The third technical scheme is related to the temperature control method of the microwave ablation needle 4 in the embodiment, the method comprises the steps that the choke ring 19, the cooling pipe 5 and the microwave radiation unit are arranged in the ablation needle 4, the microwave radiation unit comprises the microwave radiator 2 and the coaxial cable 3, the choke ring 19 is arranged on the outer side of the needle head 1, and the method comprises the step of adjusting the temperature of the flow control choke ring 19 of the cooling medium in real time according to power change or temperature change.

This implementation will be more accurate regulation thermal field temperature on above embodiment technical scheme, and the protection melts 4 whole temperatures uniform rises of needle, and other the same contents are no longer repeated.

Example four

The implementation also provides a microwave ablation needle, a first temperature control method, a second temperature control method or a third temperature control method is adopted, and the structure of the ablation needle is the same as that of the first embodiment, so that the description is omitted.

EXAMPLE five

The embodiment also provides a microwave ablation system, which comprises an ablation needle 4 and a microwave ablation instrument, wherein a cooling pipe 5 and a microwave radiation unit are arranged in the ablation needle 4, and a choke ring 19 is arranged on the outer side of the needle head 1 of the ablation needle 4;

the microwave ablator is configured to receive temperature information from the choke ring 19 and regulate the flow of the cooling medium within the cooling tube 5. The microwave radiating unit comprises a microwave radiator 2 and a coaxial cable 3. The microwave ablation instrument comprises a microwave power source, a control module, an acquisition module and a processing module.

In the actual ablation process, firstly, the pump is started to convey the cold cutting medium to the inside of the ablation needle 4 for circulation, the water temperature is generally the ambient temperature, then the microwave ablation instrument is started, and the microwave power source in the microwave ablation instrument emits microwave power to the ablation needle 4. The choke ring 19 is arranged outside the needle head 1 of the ablation needle 4, at the moment, the temperature of the choke ring 19 rises fastest and great temperature difference is formed inside the ablation needle 4, and due to overhigh temperature, the protection performance and the mechanical strength performance of the Teflon coating on the surface of the ablation needle 4 are reduced, so that the coating is easy to fall off.

The control module receives temperature information of the acquisition module, the temperature information comes from information acquired by a thermocouple inside the ablation needle 4 or information acquired in real time by the temperature measurement needle, and the control module controls the processing module to adjust the flow of the cold cutting medium according to the temperature information.

The technical scheme of the invention can measure the temperature by a thermocouple arranged on the ablation needle 4, and can also directly measure the central temperature of the thermal field by using the existing temperature measuring needle, wherein the central temperature of the thermal field is the temperature of the choke ring.

The invention has been described in detail hereinabove with reference to specific exemplary embodiments thereof. It will, however, be understood that various modifications and changes may be made without departing from the scope of the invention as defined in the appended claims. The detailed description and drawings are to be regarded as illustrative rather than restrictive, and any such modifications and variations are intended to be included within the scope of the present invention as described herein. Furthermore, the background is intended to be illustrative of the state of the art as developed and the meaning of the present technology and is not intended to limit the scope of the invention or the application and field of application of the invention.

Claims

1. A temperature control method of a microwave ablation needle is characterized by comprising the following steps: comprises a choke ring, a cooling tube and a microwave radiation unit, wherein the cooling tube and the microwave radiation unit are arranged in the ablation needle, the choke ring is arranged on the outer side of the needle head, and the method comprises the step of controlling the temperature of the choke ring by using a cooling medium.

2. A temperature control method of a microwave ablation needle is characterized by comprising the following steps: comprising a choke ring, as well as a cooling tube and a microwave radiation unit arranged inside the ablation needle, the choke ring being arranged outside the needle head, the method comprising controlling the starting temperature of the choke ring with a cooling medium.

3. A temperature control method of a microwave ablation needle is characterized by comprising the following steps: the method comprises the steps that a choke ring, a cooling pipe and a microwave radiation unit are arranged in an ablation needle, the choke ring is arranged on the outer side of the needle head, and the temperature of the choke ring is controlled by adjusting the flow of a cooling medium in real time according to power change or temperature change.

4. A method of controlling the temperature of a microwave ablation needle according to any one of claims 1 to 3, wherein: the choke ring has a length less than the length of the radiating area of the microwave radiating unit.

5. A method of controlling the temperature of a microwave ablation needle according to any one of claims 1 to 4, wherein: the choke ring is arranged at the rear end of the transmitting antenna by 1-3 mm and is 1-2 mm away from the outer layer of the coaxial cable of the transmitting antenna.

6. A method of controlling the temperature of a microwave ablation needle according to any one of claims 1 to 5, wherein: the choke ring is made of any one of copper, gold, silver, palladium, platinum, tin, nickel, zinc and alloy thereof.

7. A method of controlling the temperature of a microwave ablation needle according to any one of claims 1 to 3, wherein: and a thermocouple wire is arranged on the outer side of the needle head.

8. A method of controlling the temperature of a microwave ablation needle according to any one of claims 1 to 3 or 7, characterized in that: the tail of the needle head is provided with a clamping groove, and glue is filled in the clamping groove, so that the needle head is connected with the needle rod in an adhesive mode.

9. A microwave ablation needle using the temperature control method according to any one of claims 1 to 8.

10. A microwave ablation system, characterized by: the microwave ablation device comprises an ablation needle and a microwave ablation instrument, wherein a cooling pipe and a microwave radiation unit are arranged in the ablation needle, and a choke ring is arranged on the outer side of a needle head of the ablation needle;