A microwave ablation electrode

Abstract

This invention discloses a microwave ablation electrode, relating to the field of medical device technology. It mainly includes a main needle body, whose working end can release microwave energy to achieve microwave ablation. The main needle body is equipped with a non-working end circulating cooling structure and a working end liquid injection structure. The non-working end circulating cooling structure allows a cooling medium to reach the non-working end of the main needle body to cool the non-working end and surrounding tissue, and also allows for the return flow of the cooling medium. The working end liquid injection structure allows a cooling medium to reach the working end of the main needle body to cool the working end and surrounding tissue, and also allows the cooling medium to be injected into the lesion tissue, absorbing microwave energy to form steam, achieving steam thermal ablation. This invention achieves dual ablation through steam thermal ablation and microwave ablation, improving the ablation effect, reducing the temperature of the working end of the microwave ablation electrode, and increasing the moisture content of the tissue surrounding the working end, thus reducing carbonization of the lesion tissue.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a microwave ablation electrode. Background Technology

[0002] Microwave ablation is a relatively mature and commonly used ablation method. It is mainly used to treat nodules, tumors, and other diseases in human tissues and organs. It mainly relies on the heat generated by the friction and collision of polar molecules (water molecules) in the microwave field. The thermal effect causes the proteins in cancer cells to denature and coagulate, leading to irreversible necrosis and thus killing tumor cells. Microwave ablation therapy involves inserting the working end of the ablation electrode into the lesion site and releasing microwave energy, which raises the temperature of the cells in the lesion site, causing denaturation and ultimately necrosis of the diseased tissue. The tissue is then absorbed and cleared through the body's normal metabolism, achieving the goal of eliminating nodules and tumors.

[0003] Because microwaves radiate energy into the surrounding space after being emitted from a microwave generator, some of this energy generates a temperature rise after passing through the coaxial semi-rigid wire and the working end of the electrode. Therefore, most conventional microwave ablation electrodes have an internal cooling circulation structure; such as Figure 1 As shown, existing microwave ablation electrodes typically employ a semi-needle cold circulation structure, which is a cold circulation structure set behind the reflective ring 110. This structure can only cool the coaxial semi-rigid line behind the reflective ring 110, but cannot cool the working end of the ceramic needle body 102, let alone the tissue around the working end.

[0004] The principle of microwave ablation dictates that the transmitting antenna itself will generate heat, especially as the tissue near the working end carbonizes and loses water, causing a change in characteristic impedance, which in turn leads to severe overheating at the microwave transmitting end. Since the working end of the microwave ablation electrode is usually made of ceramic, while the outer needle tube is mostly made of metal, the two are typically bonded together with a sealing adhesive. When the transmitting antenna itself heats up severely, the sealing adhesive is prone to melting, reducing the bonding strength. At the same time, the high-temperature and high-pressure gas generated inside the working end can cause the ceramic needle to detach from the outer needle tube. In severe cases, the detached ceramic needle may puncture other important sites under the pressure of the gas, posing a significant medical risk. Furthermore, the concentrated microwave heat can easily cause carbonization of the tissue around the working end, hindering the continuous input of microwave energy, resulting in a small ablation area, irregular ablation shape, and carbonized lesions that affect the prognosis. Summary of the Invention

[0005] The purpose of this invention is to provide a microwave ablation electrode to solve the problems existing in the prior art. It can achieve dual ablation by steam thermal ablation and microwave ablation, improve the ablation effect, reduce the temperature of the working end of the microwave ablation electrode, and increase the moisture content of the tissue around the working end, thereby reducing the carbonization of the lesion tissue.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a microwave ablation electrode, comprising: a main needle body, wherein the working end of the main needle body is capable of releasing microwave energy to achieve microwave ablation; the main needle body is further provided with a non-working end circulating cooling structure and a working end liquid injection structure, wherein...

[0008] The non-working end circulating cooling structure allows the cooling medium to reach the front end of the non-working end of the main needle body to cool the non-working end of the main needle body and the surrounding tissue, and the non-working end circulating cooling structure allows the cooling medium to flow back.

[0009] The working end injection structure allows the cold medium to reach the working end of the main needle body to cool the working end of the main needle body and the surrounding tissue. It also allows the cold medium to be injected into the lesion tissue and absorb microwave energy to form steam, thereby achieving steam thermal ablation.

[0010] Preferably, the main needle body includes an inner needle tube, an outer needle tube, a reflective ring, a coaxial semi-rigid wire, and a working end needle body. The outer needle tube is sleeved on the inner needle tube, the inner needle tube is sleeved on the coaxial semi-rigid wire, the reflective ring is sleeved on the coaxial semi-rigid wire, the inner wall of the reflective ring is sealed to the outer wall of the coaxial semi-rigid wire, and the reflective ring can seal the front end of the inner needle tube. The working end needle body is disposed at the front end of the outer needle tube. The front end of the coaxial semi-rigid wire is electrically connected to a transmitting antenna, and the tail end can be electrically connected to a microwave ablation host. The transmitting antenna is located inside the working end needle body.

[0011] A connecting gap is provided between the transmitting antenna and the inner wall of the working end needle body, and between the front end of the coaxial semi-rigid wire and the inner wall of the working end needle body, forming a working end flow channel. The working end flow channel is connected to the non-working end circulating cooling structure, and the working end needle body is provided with micropores that allow cold medium to be injected into the lesion tissue. The micropores are connected to the working end flow channel, forming the working end injection structure.

[0012] Preferably, an inner flow channel is formed between the inner needle tube and the coaxial semi-rigid wire, and an outer flow channel is formed between the outer needle tube and the inner needle tube. The front end of the inner flow channel and the front end of the outer flow channel are connected, and the tail end of the inner flow channel and the tail end of the outer flow channel are respectively connected to the liquid outlet and liquid return port of the liquid supply device, forming the non-working end circulating cooling structure. The liquid supply device can provide the cooling medium, and the outer flow channel is connected to the working end flow channel.

[0013] Preferably, the tail end of the main needle body is connected to a liquid chamber, and the liquid chamber is provided with a water inlet chamber and a water return chamber that are separated from each other. The tail ends of the inner flow channel and the outer flow channel are respectively connected to the water inlet chamber and the water return chamber; wherein the water inlet chamber and the water return chamber are respectively connected to the liquid outlet and the liquid return port of the liquid supply device through the water inlet pipe and the water return pipe.

[0014] Preferably, a water flow regulating device is installed on the inlet pipe and / or the return pipe. The water flow regulating device is used to regulate the inlet or return water flow of the cold medium, thereby regulating the perfusion volume of the cold medium. The cold medium is sterile saline, sterile water for injection, or liquid medicine. The perfusion volume of the cold medium is the volume of the cold medium entering the human body per unit time, and the perfusion volume of the cold medium is 0.1 ml to 2.0 ml per minute.

[0015] Preferably, a side hole is provided on the front end side of the inner needle tube, and the inner flow channel communicates with the outer flow channel through the side hole.

[0016] Preferably, a first gap is provided between the outer wall of the reflective ring and the inner wall of the outer needle tube, and a second gap is provided between the front end face of the reflective ring and the tail end face of the working needle body. The first gap is connected to the outer flow channel, and the second gap is connected to the working end flow channel. The first gap is connected to the second gap, so as to realize the connection between the working end flow channel and the outer flow channel.

[0017] The spacing of the first gap is 0.05mm-0.2mm, and the spacing of the second gap is 0.1mm-1.0mm.

[0018] Preferably, the outer needle tube is made of metal material and can be shielded. An anti-stick insulating layer is provided on the outer wall of the outer needle tube. An anti-stick layer is provided on the outer wall of the working end needle body. The anti-stick layer is offset from the micropores and is flush with the anti-stick insulating layer.

[0019] Preferably, the diameter of the main needle body is at least 1.20 mm.

[0020] Preferably, the working end needle body includes a ceramic needle body and a ceramic needle tip. The tail end of the ceramic needle body is connected to the front end of the outer needle tube, and the front end of the ceramic needle body is provided with the ceramic needle tip. The micropore is formed on the ceramic needle body, and the ceramic needle tip is provided with a developing groove.

[0021] Preferably, the diameter of the micropores is 50μm-200μm.

[0022] The present invention achieves the following technical effects compared to the prior art:

[0023] The main needle body of this invention is provided with a working end liquid injection structure, which allows a cooling medium to reach the working end of the main needle body to cool the working end and surrounding tissue. This reduces the temperature of the working end of the main needle body, preventing the adhesive at the joint between the working end and the outer needle tube from melting at high temperatures and causing the working end needle body to detach. Furthermore, the working end liquid injection structure of this invention can also inject the cooling medium into the lesion tissue, thereby increasing the wettability of the tissue around the working end, reducing the temperature of the surrounding tissue, preventing tissue carbonization, maintaining the characteristic impedance of the tissue for a longer period, which is beneficial for microwave energy injection, thus expanding the ablation range and making the ablation shape more regular. Moreover, during the process of the cooling medium entering the lesion tissue, it absorbs microwave energy and can form high-temperature steam, achieving steam thermal ablation, thus realizing dual ablation through microwave ablation and steam thermal ablation, improving the ablation effect. Further, the working end liquid injection structure can release high-pressure gas inside the working end during liquid injection, preventing the working end needle body from breaking under high pressure. The non-working end circulating cooling structure can also release high-pressure gas.

[0024] Meanwhile, the main needle body of the present invention is also provided with a non-working end circulating cooling structure, which can provide a cooling medium to cool the non-working end of the main needle body and the surrounding tissue, and can also provide a cooling medium reflux, avoiding the non-working end of the main needle body from being too hot and burning normal tissue, as well as damaging the coaxial semi-rigid wire, and can output higher microwave power and improve ablation efficiency. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of a microwave ablation electrode in the prior art;

[0027] Figure 1 In the middle: 101. Ceramic needle tip, 102. Ceramic needle body, 103. Teflon coating, 104. Inner conductor, 105. Insulating medium, 106. Outer conductor, 107. Outer needle tube, 108. Inner needle tube, 109. Circular hole on the inner needle tube, 110. Reflector ring, 111. Sealing adhesive, 112. Solder joint, 113. Transmitting antenna;

[0028] Figure 2 This is a schematic diagram of the structure of the microwave ablation electrode in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the main needle body in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the micropore arrangement in an embodiment of the present invention;

[0031] In the diagram: 1. Ceramic needle tip, 2. Ceramic needle body, 3. Transmitting antenna, 4. Sealing adhesive, 5. Outer needle tube, 6. Reflector ring, 7. Inner needle tube, 8. Outer conductor, 9. Insulating medium, 10. Inner conductor, 11. Side hole, 12. First solder joint, 13. Return water chamber, 14. Inlet water chamber, 15. Microwave connector, 16. Second solder joint, 17. Anti-stick insulating layer, 18. Micropore, 19. Third solder joint, 20. Anti-stick layer, 21. Developing groove, 22. Return water pipe, 23. Multi-position adjustment switch, 24. Inlet water pipe. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The purpose of this invention is to provide a microwave ablation electrode to solve the problems existing in the prior art. It can achieve dual ablation by steam thermal ablation and microwave ablation, improve the ablation effect, reduce the temperature of the working end of the microwave ablation electrode, and increase the moisture content of the tissue around the working end, thereby reducing the carbonization of the lesion tissue.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Example 1

[0036] like Figures 2-4 As shown, this embodiment provides a microwave ablation electrode, mainly comprising: a main needle body, wherein the main needle body is provided with a non-working end circulating cooling structure and a working end liquid injection structure, wherein the non-working end circulating cooling structure allows the cold medium to flow from the tail end of the non-working end of the main needle body to the front end of the non-working end of the main needle body to cool the non-working end of the main needle body and the surrounding tissue, and the non-working end circulating cooling structure allows the cold medium to flow back; the working end liquid injection structure allows the cold medium to reach the working end of the main needle body to cool the working end of the main needle body and the surrounding tissue, and allows the cold medium to be injected into the lesion tissue to form high-temperature steam, thereby realizing steam thermal ablation.

[0037] In this embodiment, the main needle body is provided with a non-working end circulating cooling structure, which can provide a cooling medium to cool the non-working end of the main needle body and the surrounding tissue, and can also provide a cooling medium reflux, avoiding excessive temperature at the non-working end of the main needle body from burning normal tissue and damaging the coaxial semi-rigid wire, and can output higher microwave power to improve ablation efficiency.

[0038] Meanwhile, in this embodiment, the main needle body is also equipped with a working end injection structure, which allows the cold medium to reach the working end of the main needle body to cool the working end portion of the main needle body (the working end needle body and its internal transmitting antenna, the front end of the coaxial semi-rigid wire, and the adhesive at the bonding point between the working end needle body and the outer needle tube 5, etc.) and the surrounding tissue. This reduces the temperature of the working end of the main needle body, preventing the adhesive at the bonding point between the working end needle body and the outer needle tube 5 from melting at high temperatures, which could cause the working end needle body to detach. Moreover, in this embodiment, the working end injection structure can also inject the cold medium into the lesion tissue, thereby increasing the wettability of the tissue around the working end, reducing the temperature of the tissue around the working end, preventing tissue carbonization, maintaining the characteristic impedance of the tissue for a long time, which is conducive to the injection of microwave energy, thereby expanding the ablation range and making the ablation shape more regular, forming a spherical ablation shape; and after the cold medium enters the lesion tissue, it can evaporate to form high-temperature steam, realizing steam thermal ablation, thus achieving dual ablation of microwave ablation and steam thermal ablation, improving the ablation effect.

[0039] Furthermore, the working end liquid injection structure can release the high-pressure gas inside the working end while injecting liquid, preventing the working end needle from breaking under high pressure. The non-working end circulating cooling structure can also release high-pressure gas.

[0040] In this embodiment, the specific structure of the main needle body is similar to that of commonly used microwave ablation needles in the prior art, mainly including an inner needle tube 7, an outer needle tube 5, a reflective ring 6, a coaxial semi-rigid wire, and a working end needle body. The outer needle tube 5 is sleeved on the inner needle tube 7, and the inner needle tube 7 is sleeved on the coaxial semi-rigid wire. The reflective ring 6 is also sleeved on the coaxial semi-rigid wire. The inner wall of the reflective ring 6 seals against the outer wall of the coaxial semi-rigid wire, and the reflective ring 6 can seal the front end of the inner needle tube 7. The working end needle body is disposed on the inner needle tube 7. The front end of the outer needle tube 5 is electrically connected to the front end of the coaxial semi-rigid wire, and the rear end can be electrically connected to the microwave ablation host. The transmitting antenna 3 is located inside the working end needle body and is used to radiate microwave energy. Both the reflector ring 6 and the transmitting antenna 3 are made of metal. The coaxial semi-rigid wire includes an inner conductor 10, an insulating medium 9, and an outer conductor 8 arranged sequentially from the inside to the outside. The inner conductor 10 is used to transmit microwave energy, and its front end is electrically connected to the transmitting antenna 3 through a third solder point 19. The insulating medium 9 and the outer conductor 8 are used to shield microwave energy. The above structure is a mature existing technology in this field and will not be described in detail in this embodiment.

[0041] In this embodiment, the transmitting antenna 3 is preferably a T-shaped transmitting antenna. Depending on actual needs, other shapes of transmitting antenna 3 can also be selected, such as a linear transmitting antenna.

[0042] In this embodiment, an inner flow channel is formed between the inner wall of the inner needle tube 7 and the outer wall of the coaxial semi-rigid wire. The front end of the inner flow channel is sealed by the tail end face of the reflective ring 6. The cooling medium in the inner flow channel can reach the front end of the non-working end of the main needle body, which is the tail end of the reflective ring 6. An outer flow channel is formed between the inner wall of the outer needle tube 5 and the outer wall of the inner needle tube 7. The front end of the inner flow channel and the front end of the outer flow channel are connected, and the tail end of the inner flow channel and the tail end of the outer flow channel are respectively connected to the outlet and return port of the liquid supply device, forming the non-working end circulating cooling structure. The liquid supply device stores the cooling medium, the outlet is used to supply the cooling medium, and the return port is used to supply the cooling medium to flow back to the liquid supply device. In this embodiment, the non-working end circulating cooling structure cools the non-working end of the main needle body and the surrounding tissue, mainly cooling the coaxial semi-rigid wire, the inner needle tube 7, the outer needle tube 5, and the normal tissue around the outer needle tube 5.

[0043] In this embodiment, a gap is provided between the outer wall of the transmitting antenna 3 and the inner wall of the working end needle body, preferably 0.1mm-0.5mm. A gap is also provided between the front end of the coaxial semi-rigid wire and the inner wall of the working end needle body. These two gaps are connected to form a working end flow channel, which is connected to the outer flow channel, allowing the cold medium in the outer flow channel to flow into the working end flow channel. Furthermore, the working end needle body is provided with micropores 18 for injecting the cold medium into the lesion tissue. These micropores 18 are connected to the working end flow channel, forming the working end injection structure. The micropores 18 are located on the working end of the main needle body, which is the part of the main needle body capable of releasing microwave energy.

[0044] In this embodiment, after the cold medium enters the working end channel, it can overflow from the micropore 18. The micropore 18 has a small aperture, which ensures that only a small amount of cold medium overflows from the micropore 18, minimizing the impact on the human body. At the same time, the injected small amount of cold medium can be converted into high-temperature steam at high temperature, serving as an auxiliary ablation medium to expand the ablation range and shorten the ablation time. Moreover, the micropore 18, the working end channel, and the outer channel can also release the internal pressure generated inside the working end of the microwave ablation electrode due to high temperature, preventing the risk of needle breakage due to excessive pressure.

[0045] In this embodiment, the tail end of the main needle body is connected to a liquid chamber, which contains a spaced-apart inlet chamber 14 and a return chamber 13. The tail ends of the inner flow channel and the outer flow channel are respectively connected to the inlet chamber 14 and the return chamber 13. The inlet chamber 14 and the return chamber 13 are respectively connected to the outlet and return port of the liquid supply device via an inlet pipe 24 and a return pipe 22. The liquid supply device can be selected according to specific working needs, such as a liquid supply bottle or a liquid supply tank. Specifically, for example... Figure 2 As shown, the liquid chamber is provided with a return water chamber 13 and an inlet water chamber 14 from front to back. The return water chamber 13 and the inlet water chamber 14 are separated by a partition. The tail end of the outer needle tube 5 is connected to the return water chamber 13. The tail end of the inner needle tube 7 passes through the return water chamber 13 and the partition in sequence and extends into the inlet water chamber 14 to achieve communication. The inner needle tube 7 is connected to the partition through the second welding point 16.

[0046] In this embodiment, a water flow regulating device is installed on the inlet pipe 24 and / or the return pipe 22. This device regulates the inlet or return flow of the refrigerant, thereby adjusting the refrigerant injection volume. The water flow regulating device can be selected according to specific operational needs, such as a multi-position regulating switch 23 or a multi-position hose clamp. In a preferred embodiment, the water flow regulating device is only installed on the return pipe 22. The refrigerant injection volume is controlled by controlling the return water flow. When the refrigerant injection volume is insufficient, the return water flow is reduced, increasing the injection volume; conversely, when the injection volume is large, the opposite occurs.

[0047] In this embodiment, the cold medium is sterile saline, sterile water for injection, or a liquid drug. The infusion volume of the cold medium is the volume of the cold medium entering the human body per unit time, and the preferred infusion volume is 0.1 ml to 2.0 ml per minute. Furthermore, using a liquid drug as the cold medium in this embodiment allows for combined drug therapy, increasing efficacy, shortening the treatment cycle, and avoiding additional drug treatment steps, thus reducing patient discomfort.

[0048] In this embodiment, a side hole 11 is provided on the front end side of the inner needle tube 7, and the inner flow channel communicates with the outer flow channel through the side hole 11; a first gap of 0.05mm-0.2mm is provided between the outer wall of the reflective ring 6 and the inner wall of the outer needle tube 5, and a second gap of 0.1mm-1.0mm is provided between the front end face of the reflective ring 6 and the tail end face of the working end needle body. The first gap communicates with the outer flow channel, and the second gap communicates with the working end flow channel, thereby realizing the communication between the working end flow channel and the outer flow channel.

[0049] In this embodiment, the flow process of the cooling medium is as follows:

[0050] The cold medium in the liquid supply device enters the inner flow channel of the inner needle tube 7 through the water inlet pipe 24 and the water inlet chamber 14, and then flows out from the side hole 11 at the front end of the inner needle tube 7. Part of it flows back to the liquid supply device through the outer flow channel, and the other part is infused into the lesion tissue through the gap between the part of the inner needle tube 7 in front of the side hole 11 and the outer needle tube 5 - the first gap - the second gap - the inside of the working end needle body - the working end flow channel - the micropore 18.

[0051] In this embodiment, the working end needle body mainly includes a ceramic needle body 2 and a ceramic needle tip 1. The tail end of the ceramic needle body 2 is connected to the front end of the outer needle tube 5 through a sealing adhesive 4. The ceramic needle tip 1 is provided at the front end of the ceramic needle body 2. The diameter of the tail end of the ceramic needle body 2 is smaller than the diameter of the front end of the outer needle tube 5. The tail end of the ceramic needle body 2 can extend into the front end of the outer needle tube 5 and is connected by the sealing adhesive 4 to improve the connection strength. The microhole 18 is formed on the working end of the ceramic needle body 2. The working end of the ceramic needle body 2 is the part of the ceramic needle body 2 that is not connected to the outer needle tube 5 and is exposed. Furthermore, the working end needle body can also be made of other materials, such as plexiglass or polymer plastic needle body.

[0052] In this embodiment, as Figure 4 As shown, a ring of microholes 18 is provided on each of the three sets of circumferences at distances of a, a+b, and a+b+c from the front end of the ceramic needle tip 1 on the ceramic needle body 2. Each ring has three microholes 18 evenly distributed circumferentially, for a total of nine microholes 18. The microholes 18 in each ring correspond one-to-one with each other. The lines connecting the centers of the first, second, and third microholes in each ring are parallel to the center line of the outer needle tube 5. Preferably, a is 5mm-7mm, a+b is 8mm-10mm, and a+b+c is 11mm-13mm. The distance of the microholes 18 from the front end of the ceramic needle tip 1, the number of rings of microholes 18, and the number of microholes 18 in each ring can be selected according to actual needs.

[0053] Furthermore, the micropores 18 can be round, square, or other shapes. The number of micropores 18 in each ring can be the same or different. The centers of the micropores 18 in each ring can be coaxially distributed or intersecting.

[0054] In this embodiment, the pore size of the micropore 18 is preferably 50μm-200μm, and more preferably 50μm.

[0055] In this embodiment, the ceramic needle tip 1 is a sharpened triangular needle tip, and there is a ring of imaging grooves 21 at the connection between the ceramic needle tip 1 and the ceramic needle body 2, forming an uneven surface that is clearly visible under imaging equipment, preventing side effects such as pneumothorax, bleeding, and tumor implantation caused by repeated positioning punctures due to accidental puncture or incomplete puncture.

[0056] In this embodiment, it should be noted that the front end is the end close to the tip of the ceramic needle tip 1, and the tail end is the end away from the tip of the ceramic needle tip 1.

[0057] In this embodiment, the outer needle tube 5 is made of metal material, which can ensure sufficient strength with a small diameter, so that the diameter of the main needle body can be as small as 1.20mm (the diameter of the main needle body can preferably be 1.20mm-1.50mm). During puncture, the puncture trauma is reduced. Especially when applied to the ablation of small lung nodules, it can avoid the pneumothorax problem caused by the large diameter of the microwave ablation electrode. It should be noted that the diameter of the main needle body refers to the outer diameter of the main needle body, that is, the outer diameter of the outer needle tube 5 and the ceramic needle body 2.

[0058] In this embodiment, since the outer needle tube 5 is made of metal, an anti-adhesion insulating layer 17 is provided on the outer wall of the outer needle tube 5 to ensure insulation. This prevents the outer needle tube 5 from adhering to surrounding tissues while achieving insulation. An anti-adhesion layer 20 is provided on the outer wall of the working needle body to prevent the working needle body from adhering to surrounding tissues. The anti-adhesion layer 20 is offset from the micropores 18 to prevent the cold medium from flowing out through the micropores 18. Furthermore, the anti-adhesion layer 20 is flush with the anti-adhesion insulating layer 17, forming a smooth circumferential surface on the outer wall of the main needle body for easy puncture. In this embodiment, both the anti-adhesion insulating layer 17 and the anti-adhesion layer 20 are preferably Teflon coatings, and both are integrally formed.

[0059] In this embodiment, the outer needle tube 5 is shielded to achieve microwave shielding. Specifically, a microwave connector 15 is installed at the tail end of the liquid cavity. The tail end of the coaxial semi-rigid wire is electrically connected to the microwave ablation host through the microwave connector 15 to achieve microwave energy transmission. The shell of the microwave connector 15 is grounded. The liquid cavity is made of metal. The tail end of the outer needle tube 5 is electrically connected to the liquid cavity through the first solder point 12 and is connected to the shell of the microwave connector 15 through the liquid cavity to achieve grounding. Alternatively, the outer needle tube 5 can be directly connected to the ground wire to achieve grounding. The inner needle tube 7 is also made of metal and is grounded. Specifically, the front end of the inner needle tube 7 is electrically connected to the reflective ring 6, and the tail end is electrically connected to the liquid cavity through the second solder point 16 and is connected to the shell of the microwave connector 15 through the liquid cavity to achieve grounding.

[0060] In this embodiment, a plastic insulating layer is also provided outside the liquid cavity.

[0061] This invention is based on the fundamental principle of microwave ablation (water can absorb most of the microwave energy and generate a thermal effect). By perfusing a small amount of cold medium, the water content of the lesion tissue is increased, thereby increasing the absorption of microwave energy by the lesion tissue and converting it into a thermal effect. The small amount of perfused cold medium can be converted into high-temperature steam at high temperatures, realizing steam thermal ablation and expanding the ablation range. It can also moisten the lesion tissue, maintain characteristic impedance, and facilitate the continuous output of microwave energy, thereby expanding the ablation range.

[0062] Furthermore, this invention reduces the temperature of the working end and the outer needle tube by circulating a cold medium, thereby lowering the temperature of the lesion tissue near the working end and the temperature of the normal tissue around the outer needle tube, preventing carbonization of the lesion tissue and thermal damage to non-treatment sites. At the same time, the micropores provided on the outer flow channel and the working end can also serve as channels for the microwave ablation electrode to release high-temperature and high-pressure gas, avoiding breakage of the working end needle body.

[0063] In addition to its cold circulation and liquid perfusion functions, this invention also features adjustable perfusion flow rate. Furthermore, the microwave ablation electrode of this invention has a small diameter, resulting in clear imaging under imaging equipment. It is a safe and effective microwave ablation electrode applicable to diseases such as lung tumors and pulmonary nodules. Moreover, it should be further noted that this invention includes, but is not limited to, applications for the treatment of lung tumors and nodules. Microwave ablation electrodes derived from the principles and structure of this invention for other lesion sites are all understood to be within the scope of protection of this patent.

[0064] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A microwave ablation electrode, characterized in that: include: The main needle body has a working end that can release microwave energy to achieve microwave ablation. The main needle body is also equipped with a non-working end circulating cooling structure and a working end liquid injection structure, wherein... The non-working end circulating cooling structure allows the cooling medium to reach the front end of the non-working end of the main needle body to cool the non-working end of the main needle body and the surrounding tissue, and the non-working end circulating cooling structure allows the cooling medium to flow back. The main needle body includes an inner needle tube, an outer needle tube, a reflective ring, a coaxial semi-rigid wire, and a working end needle body. The outer needle tube is sleeved on the inner needle tube, the inner needle tube is sleeved on the coaxial semi-rigid wire, and the reflective ring is sleeved on the coaxial semi-rigid wire. The inner wall of the reflective ring is sealed to the outer wall of the coaxial semi-rigid wire, and the reflective ring can seal the front end of the inner needle tube. The working end needle body is located at the front end of the outer needle tube. The front end of the coaxial semi-rigid wire is electrically connected to a transmitting antenna, and the tail end can be electrically connected to a microwave ablation host. The transmitting antenna is located inside the working end needle body. A connecting gap is provided between the transmitting antenna and the inner wall of the working end needle body, and between the front end of the coaxial semi-rigid wire and the inner wall of the working end needle body, forming a working end flow channel. The working end flow channel is connected to the non-working end circulating cooling structure, and the working end needle body is provided with micropores that allow cold medium to be injected into the lesion tissue. The micropores are connected to the working end flow channel, forming the working end injection structure. An inner flow channel is formed between the inner needle tube and the coaxial semi-rigid wire, and an outer flow channel is formed between the outer needle tube and the inner needle tube. The front end of the inner flow channel and the front end of the outer flow channel are connected, and the tail end of the inner flow channel and the tail end of the outer flow channel are respectively connected to the liquid outlet and liquid return port of the liquid supply device, forming the non-working end circulating cooling structure. The liquid supply device can provide the cooling medium, and the outer flow channel is connected to the working end flow channel. A first gap is provided between the outer wall of the reflective ring and the inner wall of the outer needle tube, and a second gap is provided between the front end face of the reflective ring and the tail end face of the working needle body. The first gap is connected to the outer flow channel, and the second gap is connected to the working end flow channel. The first gap is connected to the second gap to realize the connection between the working end flow channel and the outer flow channel. The working end injection structure allows the cold medium to reach the working end of the main needle body to cool the working end of the main needle body and the surrounding tissue. It also allows the cold medium to be injected into the lesion tissue and absorb microwave energy to form steam, thereby achieving steam thermal ablation. The working end injection structure can also release the high-pressure gas inside the working end while injecting the liquid.

2. The microwave ablation electrode according to claim 1, characterized in that: The tail end of the main needle body is connected to a liquid chamber, and the liquid chamber is provided with a water inlet chamber and a water return chamber that are separated from each other. The tail ends of the inner flow channel and the outer flow channel are respectively connected to the water inlet chamber and the water return chamber; wherein, the water inlet chamber and the water return chamber are respectively connected to the liquid outlet and the liquid return port of the liquid supply device through the water inlet pipe and the water return pipe.

3. The microwave ablation electrode according to claim 2, characterized in that: A water flow regulating device is installed on the inlet pipe and / or the return pipe. The water flow regulating device is used to regulate the inlet or return water flow of the cold medium, thereby regulating the injection volume of the cold medium. The injection volume of the cold medium is the volume of the cold medium entering the human body per unit time.

4. The microwave ablation electrode according to claim 1 or 3, characterized in that: The spacing of the first gap is 0.05mm-0.2mm, and the spacing of the second gap is 0.1mm-1.0mm.

5. The microwave ablation electrode according to claim 1, characterized in that: The outer needle tube is made of metal and can be shielded. An anti-stick insulating layer is provided on the outer wall of the outer needle tube. An anti-stick layer is provided on the outer wall of the working end needle body. The anti-stick layer is offset from the micropores and is flush with the anti-stick insulating layer.

6. The microwave ablation electrode according to claim 5, characterized in that: The minimum diameter of the main needle body is 1.20 mm.

7. The microwave ablation electrode according to claim 1, characterized in that: The working end needle body includes a ceramic needle body and a ceramic needle tip. The tail end of the ceramic needle body is connected to the front end of the outer needle tube. The front end of the ceramic needle body is provided with the ceramic needle tip. The micropore is formed on the ceramic needle body, and the ceramic needle tip is provided with a developing groove.

8. The microwave ablation electrode according to claim 7, characterized in that: The diameter of the micropores is 50μm-200μm.

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