CN215130023U

CN215130023U - Microwave ablation antenna

Info

Publication number: CN215130023U
Application number: CN202121478320.XU
Authority: CN
Inventors: 刘春江; 张震; 王军; 龙鹏程
Original assignee: Shanghai Hongchuang Medical Technologies Co ltd
Current assignee: Shanghai Hongchuang Medical Technologies Co ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2021-12-14
Anticipated expiration: 2031-06-30

Abstract

The to-be-solved main technical problem of the utility model is to provide a microwave ablation antenna, through the antenna array principle, improve the structure of antenna head to improve the circularity in ablation district. The microwave ablation antenna comprises an antenna head and a coaxial line, wherein the antenna head comprises: the compression joint section is electrically connected with the coaxial line; the multi-core antenna array is electrically connected with the crimping section; and an insulating dielectric medium for preventing the antenna core wires from contacting each other is arranged between the antenna core wires of the multi-core antenna array.

Description

Microwave ablation antenna

Technical Field

The utility model relates to a tumour treatment technical field, in particular to microwave ablation antenna.

Background

Microwave ablation is a technique of utilizing the characteristic of directional heating of electromagnetic waves to raise the temperature of tumor cells so as to kill diseased tissues. With the recognition of the concept of minimally invasive surgery, microwave ablation has been rapidly developed as an effective and accurate method of killing tumor tissue. In clinical operation, an antenna is inserted into the center of malignant tumor tissue under the assistance of imaging methods such as CT, ultrasound and the like, ablation power and ablation time are set according to the size and the position of a tumor and an ablation matrix of an ablation needle, then microwave energy is transmitted to the head of the antenna through a coaxial cable, electromagnetic waves are diffused into the tumor tissue under the radiation action of the antenna, the tissue absorbs the electromagnetic waves to generate a large amount of heat, and finally a high-temperature region is formed, so that the heat elimination of the tumor tissue is realized.

The current microwave ablation has good effect on treating tumors with the diameter less than 3cm, the microwave ablation antenna is inserted into the tumor tissue through the ablation needle, and the tumor tissue can be eliminated only by once ablation. The length of the antenna head used for small tumors is 3-5mm generally, the length antenna can ensure good ablation zone roundness, but the smaller long diameter of the ablation zone limits the ablation capacity of the antenna structure for large tumors. Therefore, for lesion tissues with large tumor diameters (greater than 3cm), multiple needle ablations or long antenna heads (5-12mm) are often used for clinical treatment. The multi-needle ablation needs to be carried out for multiple times, so that the complete ablation of the tumor can be realized, the possibility of infection of tissues around the tumor is improved, and the operation time and the pain degree of a patient are increased; the longer microwave ablation antenna head can realize wide-area ablation and further realize complete elimination of tumor tissues, but the ablation area of the long antenna head has poor roundness, electromagnetic waves are obviously propagated along the ablation needle in the reverse direction, the roundness (the short diameter of the ablation area/the long diameter of the ablation area) of the ablation area is less than 0.7 under the general condition, and the tumor shape is mostly approximate to a sphere shape, so that the clinical method also threatens a large amount of healthy tissues while killing tumor cells, and the postoperative recovery of a patient is not facilitated. Therefore, a requirement for microwave ablation is to achieve a high circularity ablation zone on the premise of complete ablation of the tumor tissue.

At present, in order to improve the roundness index of an ablation area, the outer conductor of a microwave ablation antenna is often improved, including adding a choke ring, a sleeve, a multi-slot and other structures (Huang Handinging et a1.A view of antenna designs for practical microwave ablation) [ J ] Physica 2021). Particularly, the choke loop with the length of 1/4 microwave wavelength is added on the outer conductor of the antenna, so that the electromagnetic wave radiation of the outer conductor can be effectively throttled; the sleeve is a metal cylinder structure which is not in contact with the antenna outer conductor, and can shield the electromagnetic wave on the outer conductor from radiating to surrounding tissues and effectively reduce the backward propagation phenomenon of the electromagnetic wave; the two methods for improving the roundness of the ablation area increase the outer diameter of the microwave ablation antenna, so that the outer diameter of the microwave ablation needle is enlarged, and the patient is further painful. Another widely studied method for improving the circularity of the ablation region of the microwave ablation antenna is to ring-cut a plurality of slot structures on the outer conductor (patent document CN108652738A), and since electromagnetic fields propagating into tissues in different slots have different phases, a plurality of magnetic fields can be cancelled in a far-field region, thereby optimizing the circularity index of the ablation region, but the antenna needs to be specially designed to deal with the problem of impedance matching after the antenna is subjected to such treatment.

Another method for improving the roundness of the ablation region and the tail characteristics of the ablation region without changing the structure of the microwave ablation antenna is to add a balun at the tip of the antenna. The choke ring, sleeve, and multi-slot outer conductor structure all suppress backward propagation of electromagnetic waves on the antenna outer conductor, and in fact the electromagnetic waves generated on the antenna outer conductor are due to impedance mismatch between the antenna and the feeding coaxial cable. Thus, in most cases, if the structure of the microwave ablation antenna is not impedance matched specifically, this results in the microwave ablation antenna releasing only a portion of the microwave energy into the surrounding tissue, while another portion of the microwave energy returns to the microwave source along the antenna outer conductor. These back-transmitted microwave energies create unwanted electromagnetic fields that degrade the roundness index of the microwave ablation zone, and thus baluns are often used to adjust the antenna impedance to match the coaxial cable impedance.

The methods for improving the roundness of the ablation area have good effect, and the roundness of the ablation area is not influenced by the microwave power and the ablation time. However, the above-mentioned modification of the structure of the outer conductor of the microwave ablation antenna does not increase the radiation efficiency of the microwave to the surrounding tissue, and the choke ring, the metal sleeve, and the balun increase the diameter of the antenna, which is not favorable for the interventional procedure.

SUMMERY OF THE UTILITY MODEL

The utility model provides a microwave ablation antenna can realize the improvement of antenna radiation efficiency under the prerequisite that does not increase the antenna diameter.

The technical scheme of the utility model as follows:

a microwave ablation antenna comprising an antenna head and a coaxial wire, the antenna head comprising:

the compression joint section is electrically connected with the coaxial line;

the multi-core antenna array is electrically connected with the crimping section; and an insulating dielectric medium for preventing the antenna core wires from contacting each other is arranged between the antenna core wires of the multi-core antenna array.

As a preferred embodiment of the microwave ablation antenna, the multi-core antenna array is formed by a plurality of antenna core wires which are symmetrically arranged, or the multi-core antenna array is formed by folding back and forth a single-core antenna.

As a preferred embodiment of the microwave ablation antenna, the multi-core antenna array is composed of four antenna core wires which are symmetrically arranged, the antenna core wires do not intersect with each other, and an insulating dielectric medium is filled between the antenna core wires.

As a preferred embodiment of the microwave ablation antenna, the antenna core wires are parallel to each other.

As a preferred embodiment of the microwave ablation antenna, the antenna head further includes a connecting end portion, the connecting end portion is disposed at an end opposite to the crimping section, and the connecting end portion is connected to each of the antenna core wires.

In another preferred embodiment of the microwave ablation antenna, the multi-core antenna array is formed by four symmetrically arranged antenna core wires, each antenna core wire gradually shrinks into a pointed structure, and an insulating dielectric medium is filled between each antenna core wire.

As a preferred embodiment of the microwave ablation antenna, the multi-core antenna array is formed by folding back and forth a single-core antenna, wherein the single-core antenna is bent to form two sections, one section of the two sections is connected to the crimping section, and the other section of the two sections is not connected to the crimping section.

As a preferred embodiment of the microwave ablation antenna, two sections of the single core antenna are parallel to each other.

As a preferred embodiment of the microwave ablation antenna, the thickness of the bent part of the single core antenna is greater than the thickness of the rest part of the single core antenna, and/or the length of the bent part of the single core antenna is greater than the length of the rest part of the single core antenna.

As a preferred embodiment of the microwave ablation antenna, the antenna head is made of one piece or is formed by connecting various parts with each other.

As a preferred embodiment of the microwave ablation antenna, the length of the antenna head is 5-6 mm. The length is the most direct influence factor of the antenna radiation effect, generally, in order to realize a higher ablation area, the length of the antenna head is lengthened, so the common length is 12mm, but after the antenna length is longer, a backward heating phenomenon is caused, so several schemes in the embodiment increase the efficiency of the radiator on the premise of ensuring that the antenna head is shorter. The utility model discloses a microwave ablation antenna sets up the length of antenna head and is 5-6mm, has just realized having guaranteed the ablation district scope promptly, has also guaranteed the effect of the circularity in ablation district.

As a preferred embodiment of the microwave ablation antenna, the coaxial line includes an inner conductor, an outer conductor, a dielectric layer disposed between the inner conductor and the outer conductor, and an attachment layer sleeved outside the outer conductor, wherein the inner conductor is electrically connected to the crimping section of the antenna head.

Compared with the prior art, the beneficial effects of the utility model are as follows at least:

first, the utility model provides a microwave ablation antenna, through the design of multicore antenna array, can guarantee that ablation zone has better circularity under the prerequisite that does not increase the antenna diameter to realize bigger ablation zone with shorter antenna head;

secondly, the microwave ablation antenna provided by the utility model realizes that the gain effect of the antenna is increased and the radiation efficiency of the antenna is improved under the condition of certain microwave input power;

thirdly, the utility model provides a microwave ablation antenna, wherein, the maximization of electromagnetic wave radiation is realized on the shorter antenna by the single-core folded antenna head, and the radiation of microwave is obviously strengthened by the increase of the effective radiation length of the antenna head; and the single-core folded antenna head also realizes mutual cancellation of microwave energy in a far-field region, and controls backward propagation of microwaves.

Of course, it is not necessary for any particular product to achieve all of the above-described advantages at the same time.

Drawings

Fig. 1 is a schematic structural view of a microwave ablation antenna according to embodiment 1 of the present invention;

fig. 2 is a cross-sectional view of the antenna structure of fig. 1;

fig. 3a and 3b are side and perspective views of an antenna head of a microwave ablation antenna according to embodiment 1 of the present invention;

fig. 4 is a schematic structural view of a microwave ablation antenna according to embodiment 2 of the present invention;

fig. 5a and 5b are a side view and a perspective view of an antenna head of a microwave ablation antenna according to embodiment 2 of the present invention;

fig. 6 is a schematic structural view of a microwave ablation antenna according to embodiment 3 of the present invention;

fig. 7a, 7b and 7c are side, top and perspective views of an antenna head of a microwave ablation antenna according to embodiment 3 of the present invention;

fig. 8 is a schematic structural view of a microwave ablation antenna according to embodiment 4 of the present invention;

fig. 9a and 9b are side views and perspective views of an antenna head of a microwave ablation antenna according to embodiment 4 of the present invention.

Detailed Description

The to-be-solved main technical problem of the utility model is to provide a microwave ablation antenna, through the antenna array principle, improve the structure of antenna head to the circularity in antenna ablation district when improving great tumour treatment. The microwave ablation antenna takes a coaxial line and an antenna head part as a body, the tail part of the coaxial line is connected with a feeder line and is used for transmitting microwave energy, the tip end of the coaxial line is connected with one of antenna radiators (antenna head parts) with various structures, and the coaxial line and the antenna radiator at the antenna head part are jointly used for microwave radiation. The utility model discloses antenna head structure has been designed based on array principle of antenna, antenna head is multicore, electrically conductive good material, and its inside temperature resistant insulating dielectric that can add is used for preventing the contact between the antenna heart yearn.

The utility model discloses the principle of antenna design as follows:

the utility model discloses the electromagnetic wave that microwave emitter produced can be transmitted to used antenna body, and when coaxial line transmission TEM wave, its transmission power P was:

where P is the transmission power, Em is determined by the excitation source intensity, η is the wave impedance, b is the inner diameter of the outer conductor of the coaxial cable, and a is the outer diameter of the inner conductor of the coaxial cable.

Therefore, the boundary condition of the antenna head structure can be determined, and the multi-core structures connected in series and in parallel through the inner conductors have the same electromagnetic energy, and the electromagnetic wave vectors are overlapped, so that the antenna head structure has higher gain than that of the antenna head structure which is used alone and has no direction selection. Wherein, the radiation power Pr of the antenna head can be calculated by the following formula:

in the formula, P_rIs a spokeThe power of the radiation, I is the current, and l/lambda is the electrical length.

From the above formula, the power P radiated by the antenna_rIs related to the electrical length l/lambda of the antenna, therefore the utility model designs an antenna head structure for improving the electrical length.

The utility model provides a microwave ablation antenna, this antenna body include antenna head and coaxial line, the coaxial line includes the adhesion layer of dielectric layer and cladding outer conductor between inner conductor, outer conductor, interior/outer conductor, and the antenna body is along axial extension, and one end is used for connecting coaxial cable as the feeder, and the other end (antenna head) is used for radiating the electromagnetic wave as the antenna irradiator. The antenna radiator (antenna head) has various optional structural types, and the antenna head can be in conductive connection with the inner conductor, so that electromagnetic wave radiation from a single inner conductor to the multi-core antenna is realized. The present disclosure relates to a multi-core antenna, including single core to multi-core expansion, and multi-core structures implemented by the reciprocal inflection of single core antennas. The utility model can obtain a larger ablation major diameter through the multi-core array antenna structure under the condition of not increasing the diameter of the antenna, and simultaneously realize better roundness of an ablation area; through the mutual offset effect of electromagnetic waves in a far-field region, the comet tail effect of microwave ablation is eliminated; the microwave ablation antenna can have a smaller outer diameter, and is also beneficial to reducing the outer diameter of the microwave ablation needle, so that the concept of minimally invasive surgery is realized.

The following describes the design of the present invention.

The inner conductor and the outer conductor of the coaxial line of the microwave ablation antenna of the utility model are made of materials with good conductivity, such as (but not limited to) metal materials like copper.

The coaxial line of the microwave ablation antenna is filled with a dielectric material (insulating dielectric) between the inner conductor and the outer conductor, and the dielectric material needs to have certain temperature resistance, such as (but not limited to) a polymer material such as Teflon. The material can be beneficial to maintaining the straightness of the antenna, so that the antenna is not easy to deform in the using process.

The surface attachment layer of the coaxial line of the microwave ablation antenna is made of a non-conductive dielectric material, and the dielectric material also needs certain temperature resistance, such as (but not limited to) Teflon. The structure is used for preventing the microwave ablation antenna from being connected with the ablation needle body (if the outer conductor of the microwave ablation antenna is connected with the metal structure of the ablation needle body, the shielding effect of the metal of the ablation needle body is weakened).

The main structure of the microwave ablation antenna comprises a coaxial line for microwave transmission and a microwave radiator as an antenna head. The coaxial line comprises an inner conductor, an outer conductor, a dielectric layer between the inner conductor and the outer conductor and an adhesion layer (made of dielectric) coating the outer conductor. The antenna head part is the reinforced radiation antenna structure related by the invention, and comprises a multi-core structure and a single-core inflection structure.

The antenna head that microwave ablation antenna's conduct microwave radiator is multiple assembly structure, for example can rivet reliable being connected to coaxial line inner conductor through pressing on, the utility model discloses an antenna head structure has strengthened the radiation of microwave energy, has improved the gain of antenna, is favorable to the microwave to the release of tumour tissue, and clinical process cooperation microwave melts the cooling of needle, has realized the ablation district of high circularity.

The utility model discloses an antenna head length is shorter, can be for 5-6mm usually, compare with the microwave ablation antenna of conventional short antenna head, the utility model discloses a microwave ablation antenna has realized more extensive ablation district, consequently the utility model discloses a microwave ablation antenna has not only improved ablation district relatively, has guaranteed ablation district circularity moreover.

The utility model discloses antenna head's processing method can be through multiple means, for example at first process each characteristic part of antenna head, and welding/riveting together afterwards to fill insulating material at antenna head, prevent the electric connection between the different antenna heart yearns.

The utility model discloses a microwave ablation antenna's one end is antenna radiator (antenna head), and the other end is coaxial cable connection structure (or called coaxial line). In the clinical process, the microwave ablation antenna is matched with an ablation needle for use, the ablation needle realizes puncture and positioning, the microwave ablation antenna is placed at a proper position, then a microwave generator is started, so that the microwave is released into the pathological change tissue through the microwave ablation antenna, the pathological change tissue is completely ablated, and the temperature of the pathological change tissue is required to be raised to 60 ℃ in general conditions.

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the technical aspects of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art. The invention is further described below with reference to specific embodiments.

Example 1

Referring to fig. 1 to fig. 3, the present embodiment provides a microwave ablation antenna, including: the coaxial line specifically comprises an inner conductor 5, a dielectric layer 6 between the inner conductor 5 and an outer conductor 7, an outer conductor 7 and an outer conductor adhesion layer 8, wherein the inner conductor 5, the dielectric layer 6, the outer conductor 7 and the outer conductor adhesion layer 8 are sequentially sleeved and coaxially arranged.

The antenna head 1 is electrically connected to the inner conductor 5, and specifically, the antenna head 1 and the inner conductor 5 can be reliably connected by caulking.

Wherein the outer diameter of the antenna head 1 is slightly smaller than the outer diameter of the outer conductor 7.

The antenna head 1, the inner conductor 5 and the outer conductor 7 are all made of copper alloy materials; the dielectric 6 and the outer conductor adhesion layer 8 are insulating dielectrics and are made of insulating and temperature-resistant high polymer materials (such as Teflon, insulating resin).

The antenna head 1 can be manufactured separately and then connected to the inner conductor 5.

Referring to fig. 1, the length of the antenna head 1 is marked as D1, the gap between the antenna head 1 and the outer conductor 7 is marked as D2, and the length of the outer conductor 7 not attached by the outer conductor attachment layer 8 is marked as D3. In practical use, the length settings of D1, D2 and D3 are optimally selected according to ablation targets, the general selection of D1 is 5-6mm, and the selection of D2 and D3 is 1-3 mm.

In the embodiment, one end of the coaxial line is connected with the antenna head, and the other end of the coaxial line is reliably connected with the microwave generator through the SMA connector. Specifically, the microwave generator signal transmission line is connected with the coaxial line inner conductor 5, and the coaxial line outer conductor 7 is connected with the low point position end of the microwave generator.

Referring to fig. 3b, in the present embodiment, the antenna head 1 has a four-core structure connected in parallel, specifically, a four-core antenna array with two ends connected, so that vector superposition of four electromagnetic wave radiation fields is realized, and the gain effect of the antenna is enhanced.

The antenna head 1 specifically comprises a crimping section 11, a four-core antenna array 12 and a connecting end 13, wherein the crimping section 11 can be connected with the coaxial inner conductor 5 in a crimping mode, the four-core antenna array 12 comprises four antenna core wires which are parallel to each other, and the connecting end 13 is connected with the four antenna core wires which are parallel to each other. The connecting end portion 13 can enhance the release of the electromagnetic wave from the end portion, so that the electromagnetic wave release direction is forward along the antenna head, and the tailing phenomenon of the ablation area is reduced.

The interior of the antenna head 1, specifically, the four antenna cores of the four-core antenna array 12, may be filled with an insulating dielectric material to prevent the four antenna cores from contacting each other, which may cause an asymmetric ablation zone.

Example 2

Referring to fig. 4 and fig. 5a to fig. 5b, the coaxial line structure of the microwave ablation antenna of the present embodiment is the same as that of embodiment 1, and only the difference is found at the antenna head.

The antenna head 2 of the present embodiment has a tip shape comprising a crimped section 21 and a four-core antenna array 22, which shape configuration facilitates directional release of microwaves, as shown in fig. 4, 5 a-5 b.

The crimping section 21 at one end of the antenna head 2 is crimped on the coaxial line inner conductor, the outer diameter of the crimping section 21 is slightly smaller than that of the coaxial line outer conductor 7, and the four-core antenna array 22 at the other end is gradually contracted into a pointed structure. The antenna head structure of the embodiment not only has a high gain effect, but also has good microwave emission directivity.

In this embodiment, the length of the antenna head 2 is 5mm, and a technician can make slight adjustments in the actual process.

The manufacturing method of the antenna head 2 in this embodiment may first cut a cylindrical material with a suitable length to obtain a preliminary antenna structure, and then crimp/weld 4 antenna cores into a tip structure.

Example 3

The structure of the coaxial line of the microwave ablation antenna of the present embodiment is the same as that of embodiment 1, and only the difference is found at the head of the antenna.

Referring to fig. 6, 7a and 7b, the antenna head 3 of the present embodiment has a four-core structure, including a press-connecting section 31 and a four-core antenna array 32, but does not have a connecting end portion for connecting four core wires, and is a four-core antenna array with one end connected and the other end disconnected.

The crimping section 31 at one end of the antenna head 3 is crimped on the coaxial line inner conductor, and the outer diameter of the crimping section 31 is slightly smaller than that of the coaxial line outer conductor; the four antenna cores of the four-core antenna array 32 at the other end of the antenna head 3 are electrically insulated from each other. The antenna head structure is similar to an L-shaped antenna, and the gain effect of the antenna is enhanced.

In this embodiment, the four antenna core wires need to be filled with an insulating material, so as to enhance the strength of the antenna core wires and prevent the antenna core wires from contacting with each other.

Example 4

Referring to fig. 8, 9a and 9b, the antenna head 4 of the present embodiment is only a single-core structure, but there is a single-core reverse-turn, and this structural arrangement increases the effective electrical length of the antenna, increases the radiation length of the antenna, and further increases the radiation power of the antenna significantly.

This antenna head 4 includes crimping section 41 and antenna radiation body 42, and the crimping section 41 of antenna head 4 one end is pressed and is riveted on coaxial line inner conductor, and the external diameter of crimping section 41 slightly is less than the external diameter of coaxial line outer conductor 7, and the antenna radiation body 42 of the antenna head 4 other end is the inflection department of antenna, and single core antenna forms two sections through buckling, and one of them section connect in crimping section 41, another section not with crimping section 41 connects, and above-mentioned two sections are parallel to each other.

The antenna head structure is similar to an inverted U-shaped antenna, and the radiation power of the antenna is enhanced. The inside of the antenna (between the two sections of the antenna radiator 42) may be filled with an insulating medium to prevent the folded antennas from contacting each other.

To the microwave ablation antenna of the present invention, the antenna of two-core and three-core structure is feasible, but after the radiator is reduced, the radiation area is weakened, which is not favorable for enlarging the ablation area, but still suitable for general ablation area size.

To the utility model discloses a microwave ablation antenna, the length of antenna heart yearn is main influence factor, in addition, the width and the thickness of antenna heart yearn also are secondary influence factor, generally, need the cross sectional area sum more than or equal to of each antenna heart yearn of multicore structure antenna (or called multicore antenna array) under the same regulation (the external diameter that indicates the microwave ablation antenna product is the same) the cross sectional area of single core antenna, can neglect the influence of the width and the thickness of antenna heart yearn, only show that multicore antenna structure can promote radiant efficiency.

In addition, the length, the width and the thickness of the bent section of the folded antenna are consistent with those of the antenna core main body, and because the length of the bent section is small and the radiation capability is weak, the main radiation area is the main body part of the folded antenna. However, it should be noted that if the thickness and length of the bending part are increased, the ablation area is slightly increased, which is beneficial to the roundness of the ablation area.

The utility model provides an antenna head structure accessible multiple assembly's mode preparation, also accessible one-time cutting shaping.

The utility model discloses a microwave ablation antenna has following characteristics:

1. the utility model discloses a microwave ablation antenna realizes that the gain effect of the antenna is improved under the condition of certain microwave input power by designing a multi-core antenna array; in addition, a larger ablation area is realized by using a shorter antenna head, and the ablation area is ensured to have better roundness;

2. in a preferred embodiment, the array of microwave ablation antennas of the present invention has a four-core structure, wherein the four cores are arranged in parallel, or the four cores intersect at the tip; the ablation area of the four-core structure has good symmetrical effect, and other multi-core structures can also improve the gain of the antenna, but the utility model discloses do not suggest to use too many antenna core wires in consideration of the processing characteristic of the antenna head;

3. in preferred implementation structure, the utility model also provides a microwave antenna structure of single core inflection, has realized electromagnetic wave radiation's maximize on shorter antenna, and the increase of the effective radiation length of antenna head is obvious has strengthened the radiation of microwave, the utility model provides a single core inflection structure has not only increased the antenna radiation ability, has also realized simultaneously offsetting each other at far field area microwave energy, has throttled the microwave and has propagated backward.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1.A microwave ablation antenna comprising an antenna head and a coaxial wire, the antenna head comprising:

the compression joint section is electrically connected with the coaxial line;

2. A microwave ablation antenna according to claim 1, wherein the multi-core antenna array is formed by a plurality of antenna core wires arranged symmetrically or by a single core antenna folded back and forth.

3. A microwave ablation antenna according to claim 1, wherein the multi-core antenna array is composed of four antenna cores which are symmetrically arranged, the antenna cores do not intersect with each other, and an insulating dielectric medium is filled between the antenna cores.

4. A microwave ablation antenna according to claim 2 or 3, wherein the antenna cores are parallel to each other.

5. A microwave ablation antenna according to claim 4, wherein the antenna head further includes a connecting end portion disposed at an end opposite the crimping section and connecting each of the antenna core wires.

6. A microwave ablation antenna according to claim 1 or 2, wherein the multi-core antenna array is formed by four antenna cores which are symmetrically arranged, each antenna core gradually shrinks into a pointed structure, and an insulating dielectric medium is filled between each antenna core.

7. A microwave ablation antenna according to claim 1 or 2, wherein the multi-core antenna array is formed by a single core antenna folded back and forth, wherein the single core antenna is folded to form two sections, one of which is connected to the crimping section and the other of which is not connected to the crimping section.

8. A microwave ablation antenna according to claim 7, wherein the two sections of the single core antenna are parallel to each other.

9. A microwave ablation antenna according to claim 7, wherein the thickness of the bent part of the single core antenna is greater than the thickness of the rest part of the single core antenna, and/or the length of the bent part of the single core antenna is greater than the length of the rest part of the single core antenna.

10. A microwave ablation antenna according to claim 1, wherein the antenna head is made in one piece or from parts interconnected.

11. A microwave ablation antenna according to claim 1, wherein the length of the antenna head is 5-6 mm.

12. A microwave ablation antenna according to claim 1, wherein the coaxial line includes an inner conductor, an outer conductor, a dielectric layer disposed between the inner conductor and the outer conductor, and an attachment layer sleeved outside the outer conductor, the inner conductor being electrically connected to the crimped section of the antenna head.