A medical microwave ablation antenna

Abstract

The application discloses a medical microwave ablation antenna, which comprises a radiator, a multiplexing feed network structure and a controller. The radiator is a dual-frequency narrow-band radiation antenna, and at least comprises a first monopole antenna and a second monopole antenna. The reflection plate of the first monopole antenna and the reflection plate of the second monopole antenna are oppositely arranged. The multiplexing feed network structure at least comprises a first feed network branch and a second feed network branch. The first feed network branch feeds energy to the first monopole antenna, and the second feed network branch feeds energy to the second monopole antenna. The controller is further used for controlling the frequency and power of waves to regulate the radiation intensity of the two monopole antennas respectively, so as to regulate the size and shape of the ablation area. Through the structure of the radiator and the controller, the wave emitted by the numerical control power source is regulated, so that the radiator forms an ablation area with an arbitrary shape. During the ablation operation, the dangerous area can be avoided, and the irregular tumor can be ablated. The operation accuracy is high, and the postoperative recurrence rate is reduced.

Description

Technical Field

[0001] This invention relates to the field of microwave antenna technology, and more particularly to a medical microwave ablation antenna. Background Technology

[0002] In the medical field of cancer treatment, traditional radical treatment methods mainly include surgical resection and ablation. The "Guidelines for the Diagnosis and Treatment of Primary Liver Cancer (2024 Edition)" issued by the National Health Commission of my country (hereinafter referred to as the "Guidelines") points out that compared with other ablation methods (such as radiofrequency ablation), microwave ablation is more efficient, requires less time, and can reduce the "heat sink effect" of radiofrequency ablation. It is particularly effective for tumors near blood vessels, highly vascularized tumors, and larger tumors, providing a more thorough ablation and destruction effect. The Guidelines further explicitly state that "ablation therapy is currently considered a radical treatment for small hepatocellular carcinoma besides surgical resection." Microwave ablation has become a widely adopted radical treatment method for tumors both domestically and internationally, and the engineering community has also conducted extensive research on microwave ablation-related technologies and tools (such as microwave ablation antennas).

[0003] However, traditional microwave ablation antenna technology has several key limitations, including: 1. The radiation direction and shape of traditional microwave ablation antennas are difficult to control, often resulting in only an ellipsoidal radiation area. This limits the selection of ablation sites during ablation surgery. For tumors adjacent to dangerous areas, it is often difficult to treat them because it is impossible to ablate the tumor while avoiding the dangerous area.

[0004] 2. Microwave ablation surgery involves inserting an antenna percutaneously into the body. Therefore, during the procedure, the antenna's position is almost immobile, or can only be rotated slightly without harming the patient. Consequently, it is often inserted into or near the tumor center before radiating power for ablation. However, traditional microwave ablation antennas often only produce an ellipsoidal radiation area around the antenna axis, or a semi-ellipsoidal radiation area located on one side of the antenna. This makes it difficult to achieve complete ablation of irregular tumors and is not conducive to reducing the risk of postoperative recurrence. Summary of the Invention

[0005] In view of the above problems, this invention overcomes at least one of them and proposes a medical microwave ablation antenna.

[0006] The technical solution adopted in this invention is as follows: This application provides a medical microwave ablation antenna, including a radiator, a multiplexed feed network structure, and a controller; The radiator is a dual-frequency narrowband radiating antenna, and the radiator includes at least a first monopole antenna and a second monopole antenna, with the reflector of the first monopole antenna and the reflector of the second monopole antenna arranged opposite to each other; The multiplexed feed network structure includes at least a first feed network branch and a second feed network branch. The first feed network branch is connected to the first monopole antenna and feeds the first monopole antenna, and the second feed network branch is connected to the second monopole antenna and feeds the second monopole antenna. The controller is connected to the multiplexed power supply network structure. The controller is also used to connect an external digitally controlled power source to the electrical signal and to control the frequency and power of the wave emitted by the digitally controlled power source to regulate the radiation intensity of the first monopole antenna and the second monopole antenna, thereby regulating the size and shape of the ablation region on both sides of the antenna.

[0007] In actual use, the CNC power source can also be built-in.

[0008] In this application, the first monopole antenna and the second monopole antenna are stacked back to back, that is, the reflector of the first monopole antenna and the reflector of the second monopole antenna are arranged opposite each other, and the monopole radiators of the first monopole antenna and the monopole radiators of the second monopole antenna are arranged opposite each other.

[0009] Due to the frequency selectivity of the radiator and the multiplexed feed network structure, when the input frequency of the digitally controlled power source falls within the matching frequency range of one of the first and second monopole antennas of the radiator, microwave energy is radiated from the radiator to form an ablation region.

[0010] By adjusting the frequency of the wave emitted by the digitally controlled power source through the controller, when the frequency is closer to the first monopole antenna, the ablation area formed on the side of the first monopole antenna is larger; when the frequency is closer to the second monopole antenna, the ablation area formed on the side of the second monopole antenna is larger; when the frequency is located between the first and second monopole antennas, the ablation areas formed on both sides of the first and second monopole antennas are equal in size.

[0011] This application describes a method where the radiator is configured as a stacked structure of two monopole antennas placed back-to-back. By combining this with a controller to adjust the frequency of the wave emitted by the digitally controlled power source to a suitable range, the radiator can form an ablation region of arbitrary shape (symmetrical or asymmetrical). During actual ablation surgery, for tumors adjacent to dangerous areas or irregular tumors, a suitable ablation location can be selected. Combined with the asymmetrical ablation region of the radiator, dangerous areas can be avoided, and irregular tumors can be ablated. This improves the accuracy and convenience of the ablation procedure and reduces the postoperative recurrence rate.

[0012] Furthermore, the controller is compatible with various types of standard microwave connectors. In practical applications, the appropriate type can be selected to match the commercially available power source used by the user, based on their specific needs.

[0013] Furthermore, the radiator is a dual-frequency narrowband radiating antenna manufactured using a multilayer printed circuit board process; The first monopole antenna and the second monopole antenna have the same external dimensions and center frequencies at opposite ends of the 2.4GHz~2.5GHz frequency band, respectively. The first monopole antenna and the second monopole antenna share a single layer of metal reflector.

[0014] Traditional microwave ablation antennas are relatively large, resulting in larger incisions required for microwave ablation surgery. By sharing a single metal reflector between the first and second monopole antennas, the size of the microwave ablation antenna can be reduced, thereby decreasing the size of the incision required for surgical treatment.

[0015] Furthermore, a first protective layer is formed outside the radiator, which is a non-conductive, corrosion-resistant heat-shrinkable material. The multiplex power supply network structure is manufactured using a multilayer printed circuit board process. The multiplexed power supply network structure has a second protective layer formed on its exterior. The second protective layer is a non-conductive, corrosion-resistant heat-shrinkable material.

[0016] Furthermore, the first protective layer is made of Teflon (FEP) material. The thickness of the first protective layer is 0.35 mm.

[0017] After the ablation antenna is inserted into the human body, the protective layer is used to prevent the radiator from adhering to human tissue or being corroded by body fluids.

[0018] Traditional medical microwave ablation antennas are often based on coaxial cables with a circular cross-section and are manufactured through processes such as etching and grooving. This process requires separate molds for each type of ablation antenna, resulting in low reusability and complex processes. Therefore, the manufacturing difficulty is high and the cost is high. The cost of medical devices is inevitably passed on to patients for treatment, which hinders the popularization of microwave ablation surgery to a wider range of cancer patients and does not meet the national requirement of "effectively reducing the burden of medical treatment for the masses".

[0019] The medical microwave ablation antenna provided in this application is manufactured using multilayer printed circuit board technology for both the radiator and the multiplexed feed network structure. Printed circuit board technology is simple, mature, and stable, which helps to reduce production costs.

[0020] Furthermore, the multiplexed power supply network structure includes at least one impedance transformer and three quarter-wavelength impedance transformers, which are connected in series and are all substrate-integrated coaxial cable structures.

[0021] By combining coaxial cables with substrates of different characteristic impedances, the input impedance of the antenna can be adjusted, making the input impedance open-circuit outside the resonant point, thus realizing a narrowband single-input, multi-output network. By connecting the multiplexed feed network structure (first feed network branch and second feed network branch) to the radiator (two branches of the first monopole antenna and the second monopole antenna), signals of different frequencies can enter two branches of the radiator at different resonant points through the multiplexed feed network structure, thereby controlling the radiation intensity of each branch of the radiator and thus controlling the overall radiation intensity of the radiator.

[0022] Furthermore, the multiplexed power supply network structure also includes a power supply port structure; The power supply port structure is used to connect to the numerically controlled power source; The first feed network branch and the second feed network branch are respectively connected to the feed port structure; The power emitted by the numerically controlled power source is split into the first feed network branch and the second feed network branch through the feed port structure, and then transmitted to the first monopole antenna and the second monopole antenna through the first feed network branch and the second feed network branch respectively.

[0023] Furthermore, the power supply port structure includes a top metal plate, a middle metal plate, and a bottom metal plate; The top metal plate forms a coplanar waveguide, which includes a waveguide inner conductor and a waveguide outer conductor arranged coplanarly. The outer end of the waveguide inner conductor away from the waveguide outer conductor is the input end, which is used to connect to a digitally controlled power source. The inner end of the waveguide inner conductor near the waveguide outer conductor has a metallized transition via. A first inner conductor is formed between the top metal plate and the middle metal plate, and a second inner conductor is formed between the middle metal plate and the bottom metal plate; One end of the first inner conductor and the second inner conductor are electrically connected through the metallized transition via; The other ends of the first inner conductor and the second inner conductor are respectively connected to the first feed network branch and the second feed network branch.

[0024] Furthermore, the first inner conductor is the first output port, and the second inner conductor is the second output port.

[0025] Furthermore, the bottom metal plate is used for grounding.

[0026] Furthermore, an adapter structure is welded to the input end of the inner conductor of the waveguide. The adapter structure is a coaxial connector or other conversion connector, which connects the numerically controlled power source to the coplanar waveguide.

[0027] Furthermore, a first metallized array via structure is formed on the outer conductor of the waveguide. The first metallized array via structure is an electrically conductive via. The first metallized array via structure is arranged in two columns, which are located on both sides of the first inner conductor and the second inner conductor, respectively. The two columns of first metallized array via structures, together with the top metal plate, the middle metal plate and the bottom metal plate, form the substrate integrated coaxial line structure of the feed port structure, and are correspondingly arranged with the substrate integrated coaxial line structure of the multiplex feed network structure.

[0028] Furthermore, the power supply port structure is manufactured using a multilayer printed circuit board process, and its thickness is consistent with that of the multiplexed power supply network structure. The thickness of the multiplexed power supply network structure is adapted to the thickness of the radiator.

[0029] Furthermore, a second metallized array via structure is also formed on the outer conductor of the waveguide, and the second metallized array via structure is a shielding via. The second metallized array via structure is located on both sides of the first metallized array via structure and is disposed along the outer edge of the power supply port structure.

[0030] When a CNC power source receives high-power input through a power supply port structure, if the power supply port structure itself is not shielded, microwave radiation will be generated at its corners, causing power leakage, wasting power, and reducing efficiency. By setting a second metallized array through-hole structure, power leakage can be reduced.

[0031] Furthermore, the bottom metal plate is provided with a slotted structure, which is used to prevent the input power from being directly coupled to the grounded bottom metal plate, thus avoiding power waste. The slotted structure is a circular slot or a rectangular slot: When the slotted structure is a circular slot, the circular slot is coaxially arranged with the metallized transition through hole and the bottom metal plate is a complete metal plate; When the slotted structure is a rectangular slot, the rectangular slot is provided in correspondence with the rectangular structure slot that forms a coplanar waveguide.

[0032] By setting a slotted structure, the power input from the inner conductor of the waveguide is delivered to the first monopole antenna and the second monopole antenna respectively through the metallized transition via and the two feed network branches.

[0033] Furthermore, the controller is connected from the feed port structure of the multiplexed feed network structure to couple out a portion of the reflected power. The coupled reflected power is detected to form detection information, which is then input to the controller. The controller is a programmable controller. When the reflected power information coupled from the feed port structure is input, it sends specific control commands to the numerically controlled power source as needed, so that the numerically controlled power source changes the microwave frequency and power fed into the feed port structure, and adjusts the radiation intensity of the first monopole antenna and the second monopole antenna, thereby adjusting the size and shape of the ablation region on both sides of the antenna.

[0034] In practical use, traditional microwave ablation antennas sometimes reflect input power that is not fully radiated back to the power source. This reflected energy causes the antenna to heat up, and the heat diffuses outward along the entire percutaneous insertion path, causing unnecessary burns to the patient's healthy tissue (i.e., the "tailing effect"). Traditional microwave ablation antennas use cooling systems, such as water circulation systems, to remove the unwanted heat generated by the tailing effect. However, adding such a cooling system inevitably increases the structural complexity of the microwave ablation antenna, thereby increasing manufacturing and maintenance costs. This application addresses this issue by connecting a controller to the input port of the multiplexed feed network structure to couple out a portion of the reflected power, thereby reducing the reflected power and mitigating the "tailing effect" (achieved through self-cancellation). The existing "water circulation cooling system" can be eliminated, simplifying the overall structure of the medical microwave ablation antenna and reducing its manufacturing and maintenance costs.

[0035] Furthermore, the controller is connected to a human-machine interface, allowing doctors using the ablation antenna to adjust the desired shape of the ablation area according to clinical needs. The controller maps the adjusted parameters to power and frequency information and reports it to the digitally controlled power source, enabling the shape of the ablation area to be adjusted arbitrarily as needed.

[0036] Patent application CN114366289A discloses a microwave ablation antenna and its manufacturing method. The antenna includes a needle, a coaxial cable, a non-metallic sleeve fixed behind the needle, and a hollow spacer within the non-metallic sleeve. The needle and the inner wall of the non-metallic sleeve have an inner radiator electrically connected to the inner conductor of the coaxial cable, and the outer wall of the non-metallic sleeve has an outer radiator electrically connected to the outer conductor of the coaxial cable. A water-cooling loop is also provided. The patent specification explicitly states that the ablation shape is spherical, thus exhibiting the aforementioned limitations in the shape of the radiation area. Furthermore, this design is still based on coaxial cable fabrication and still requires a water-cooling loop to counteract the unwanted heat from the tailing effect. The limitations of complex manufacturing processes and structures remain significant.

[0037] In 2021, Amira S. Ashour et al. designed a unidirectional radiation microwave ablation antenna consisting of a slotted coaxial line and a ring-shaped reflective structure, and tested its ablation performance. They verified that the antenna had 100% tumor ablation performance when inserted 11 mm below the center of the tumor, with an input power of 6 W, and radiated to a tumor with a diameter of 2-5 cm for 10 minutes.

[0038] In 2022, Wang Li et al. from Xi'an Jiaotong University designed a low-invasive, directional monopole antenna based on a coaxial structure with a circular cross-section after skin removal. This antenna can penetrate the skin into the tumor lesion without causing only a small circular incision to the patient, generating an ellipsoidal radiation area with a minor-to-major axis ratio of up to 0.4. However, both of these antennas are based on a coaxial design with a circular cross-section, resulting in complex manufacturing processes, low reusability, and high manufacturing difficulty and cost.

[0039] The medical microwave ablation antenna used in this invention is manufactured using a multilayer printed circuit board process, which has the advantages of simple design, low price, and easy mass production. At the same time, the ablation area of ​​the antenna is accurately controlled, and the radiation energy is concentrated in the area to be ablated, thereby reducing the damage to the patient's healthy tissues during the ablation surgery, reducing the difficulty of the ablation surgery, and improving the safety of the ablation surgery.

[0040] The beneficial effects of this invention are: (1) Compared with the above-mentioned existing solutions, the shape of the ablation area formed by the medical microwave ablation antenna provided in this application is controllable. That is, the ablation area of ​​any shape can be formed according to different lesions. Not only can dangerous areas be avoided, but irregular tumors can also be ablated. The accuracy and convenience of the ablation operation are improved, and the postoperative recurrence probability is reduced.

[0041] (2) The first monopole antenna and the second monopole antenna share a metal reflector, which can reduce the volume of the microwave ablation antenna and thus reduce the size of the incision required during surgical treatment.

[0042] (3) The medical microwave ablation antenna provided in this application is manufactured using multilayer printed circuit board technology for both the radiator and the multiplexed feed network structure. Printed circuit board technology is simple, mature and stable, and can reduce production costs.

[0043] (4) By connecting the controller to the input port of the multiplexed feed network structure, a portion of the reflected power is coupled out, thereby reducing the reflected power and weakening the "tail effect". The related structure of the "water circulation cooling system" in the existing structure can be omitted, making the overall structure of the medical microwave ablation antenna simpler and reducing the manufacturing and maintenance costs of the medical microwave ablation antenna.

[0044] (5) A second metallized array through-hole structure is set on the power supply port structure to reduce power leakage.

[0045] (6) A slotted structure is provided on the bottom metal plate of the power supply port structure to prevent the input power from being directly coupled to the grounded bottom metal plate. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the axial structure of the medical microwave ablation antenna according to an embodiment of the present invention (hiding the first protective layer, the second protective layer, and part of the dielectric substrate). Figure 2 yes Figure 1 A magnified schematic diagram of the structure of part A in the diagram; Figure 3 yes Figure 1 A magnified schematic diagram of the partial structure of B in the diagram; Figure 4 yes Figure 1 A magnified schematic diagram of the structure of C in the middle; Figure 5 This is a schematic diagram of the axial structure of the medical microwave ablation antenna according to an embodiment of the present invention; Figure 6 yes Figure 5 A magnified schematic diagram of the local structure of D; Figure 7 yes Figure 5 A magnified schematic diagram of a portion of the structure of E; Figure 8 This is a schematic diagram of the power supply port structure in Embodiment 1 of the present invention; Figure 9 This is a schematic diagram of the power supply port structure in Embodiment 2 of the present invention; Figure 10 This is a schematic diagram of the power supply port structure in Embodiment 3 of the present invention.

[0047] The labels for the attached figures are as follows: 10. Radiator; 101. Dielectric substrate; 110. First monopole antenna; 120. Second monopole antenna; 111. Metal reflector; 130. First protective layer; 20. Multiplexed feed network structure; 210. First feed network branch; 220. Second feed network branch; 230. Second protective layer; 30. Feed port structure; 310. Top metal plate; 311. Waveguide inner conductor; 312. Waveguide outer conductor; 313. Metallized transition via; 314. First inner conductor; 315. Second inner conductor; 316. First metallized array via structure; 317. Second metallized array via structure; 320. Middle metal plate; 330. Bottom metal plate; 331. Circular slot; 332. Rectangular slot. Detailed Implementation

[0048] The present invention will now be described in detail with reference to the accompanying drawings.

[0049] Example 1 like Figures 1-8 As shown, this application provides a medical microwave ablation antenna, including a radiator 10, a multiplexer feed network structure 20, and a controller; The radiator 10 is a dual-frequency narrowband radiating antenna. The radiator 10 includes at least a first monopole antenna 110 and a second monopole antenna 120. The reflector of the first monopole antenna 110 and the reflector of the second monopole antenna 120 are arranged opposite to each other. The multiplexed feed network structure 20 includes at least a first feed network branch 210 and a second feed network branch 220. The first feed network branch 210 is connected to the first monopole antenna 110 and feeds the first monopole antenna 110. The second feed network branch 220 is connected to the second monopole antenna 120 and feeds the second monopole antenna 120. The controller is connected to the multiplexed power supply network structure 20. The controller is also used to connect an external digitally controlled power source to the electrical signal and to control the frequency and power of the wave emitted by the digitally controlled power source to regulate the radiation intensity of the first monopole antenna 110 and the second monopole antenna 120, thereby regulating the size and shape of the ablation area on both sides of the antenna.

[0050] Due to the frequency selectivity of the radiator 10 and the multiplexed feed network structure 20, when the frequency of the digitally controlled power source input falls within the matching frequency range of one of the two monopole antennas 110 and 120 of the radiator 10, microwave energy is radiated from the radiator 10 to form an ablation region.

[0051] By adjusting the frequency of the wave emitted by the digitally controlled power source through the controller, when the frequency is closer to the first monopole antenna 110, the ablation area formed on one side of the first monopole antenna 110 is larger; when the frequency is closer to the second monopole antenna 120, the ablation area formed on one side of the second monopole antenna 120 is larger; when the frequency is between the first monopole antenna 110 and the second monopole antenna 120, the ablation areas formed on both sides of the first monopole antenna 110 and the second monopole antenna 120 are equal in size.

[0052] This application describes a method where the radiator 10 is configured as a stacked structure of two monopole antennas placed back-to-back. By combining this with a controller to adjust the frequency of the wave emitted by the digitally controlled power source to a suitable frequency range, the radiator 10 can form an ablation region of arbitrary shape (symmetrical or asymmetrical). During actual ablation surgery, for tumors adjacent to dangerous areas or irregular tumors, a suitable ablation location can be selected. Combined with the asymmetrical ablation region of the radiator 10, dangerous areas can be avoided, and irregular tumors can be ablated. This improves the accuracy and convenience of the ablation procedure and reduces the postoperative recurrence rate.

[0053] In this application, the first monopole antenna 110 and the second monopole antenna 120 are stacked back to back, that is, the reflector of the first monopole antenna 110 and the reflector of the second monopole antenna 120 are arranged opposite each other, and the monopole radiators 10 of the first monopole antenna 110 and the monopole radiators 10 of the second monopole antenna 120 are arranged opposite each other.

[0054] In this embodiment, the radiator 10 is a dual-frequency narrowband radiating antenna manufactured using a multilayer printed circuit board process. The first monopole antenna 110 and the second monopole antenna 120 have the same external dimensions and center frequencies at the two ends of the 2.4GHz~2.5GHz frequency band, respectively. The first monopole antenna 110 and the second monopole antenna 120 share a single metal reflector 111.

[0055] In this embodiment, the center frequency of the first monopole antenna 110 is 2.4 GHz, and the center frequency of the second monopole antenna 120 is 2.5 GHz.

[0056] Traditional microwave ablation antennas are relatively large, resulting in larger incisions required for microwave ablation surgery. By sharing a single metal reflector 111 between the first monopole antenna 110 and the second monopole antenna 120, the size of the microwave ablation antenna can be reduced, thereby decreasing the size of the incision required for surgical treatment.

[0057] In this embodiment, the thickness of the radiator 10 is 1.44 mm.

[0058] In this embodiment, a first protective layer 130 is formed on the outside of the radiator 10. The first protective layer 130 is a non-conductive and corrosion-resistant heat-shrinkable material. The multiplex power supply network structure 20 is manufactured using a multilayer printed circuit board process. The multi-channel power supply network structure 20 has a second protective layer 230 formed on its exterior. The second protective layer 230 is a non-conductive, corrosion-resistant heat-shrinkable material.

[0059] In this embodiment, the first protective layer 130 is made of Teflon (FEP) material. The thickness of the first protective layer 130 is 0.35 mm.

[0060] After the ablation antenna is inserted into the human body, the first protective layer is used to prevent the radiator 10 from adhering to human tissue or being corroded by body fluids.

[0061] The medical microwave ablation antenna provided in this application, the radiator 10 and the multiplexed feed network structure 20 are both manufactured using multilayer printed circuit board technology. Printed circuit board technology is simple, mature and stable, and can help reduce production and manufacturing costs.

[0062] In this embodiment, the multiplexed power supply network structure 20 includes at least one impedance transformer and three quarter-wavelength impedance transformers. The impedance transformers are connected in series with the three quarter-wavelength impedance transformers, and all of them are substrate-integrated coaxial cable structures.

[0063] By combining substrates with different characteristic impedances to integrate coaxial lines, the input impedance of the antenna can be adjusted so that the input impedance is open-circuited outside the resonant point, thus realizing a narrowband single-input, multi-output network. By connecting the multiplexing feed network structure 20 (first feed network branch 210 and second feed network branch 220) to the radiator 10 (two branches of the first monopole antenna 110 and the second monopole antenna 120), signals of different frequencies can enter the two branches of the radiator 10 at different resonant points through the multiplexing feed network structure 20, thereby controlling the radiation intensity of each branch of the radiator 10 and thus controlling the overall radiation intensity of the radiator 10.

[0064] In this embodiment, the multiplexed power supply network structure 20 also includes a power supply port structure 30; The power supply port structure 30 is used to connect to a CNC power source (either external or internal). The first feed network branch 210 and the second feed network branch 220 are respectively connected to the feed port structure 30; The power emitted by the numerically controlled power source is split through the feed port structure 30 to the first feed network branch 210 and the second feed network branch 220, and then transmitted to the first monopole antenna 110 and the second monopole antenna 120 through the first feed network branch 210 and the second feed network branch 220 respectively.

[0065] In this embodiment, the power supply port structure 30 includes a top metal plate 310, a middle metal plate 320, and a bottom metal plate 330. The top metal plate 310 forms a coplanar waveguide, which includes a waveguide inner conductor 311 and a waveguide outer conductor 312 arranged coplanarly. The outer end of the waveguide inner conductor 311 away from the waveguide outer conductor 312 is the input end, which is used to connect to the digitally controlled power source. The inner end of the waveguide inner conductor 311 near the waveguide outer conductor 312 has a metallized transition via 313 with a diameter of 0.5 mm. A first inner conductor 314 is formed between the top metal plate 310 and the middle metal plate 320, and a second inner conductor 315 is formed between the middle metal plate 320 and the bottom metal plate 330. One end of the first inner conductor 314 and the second inner conductor 315 are electrically connected through the metallized transition via 313. The other ends of the first inner conductor 314 and the second inner conductor 315 are respectively connected to the first feed network branch 210 and the second feed network branch 220.

[0066] In this embodiment, the first inner conductor 314 is the first output port, and the second inner conductor 315 is the second output port.

[0067] In this embodiment, the bottom metal plate 330 is used for grounding.

[0068] In this embodiment, an adapter structure is welded to the input end of the waveguide inner conductor 311. The adapter structure is a coaxial connector or other conversion connector, which connects the CNC power source to the coplanar waveguide. The adapter structure can be equipped with different types of adapter ports, such as coplanar waveguide to coaxial line ports, according to the user's customization needs, and can be installed by welding, thereby facilitating connection with the CNC power source.

[0069] In this embodiment, a first metallized array via structure 316 is also formed on the outer waveguide conductor 312. The first metallized array via structure 316 is an electrically conductive via. The first metallized array via structure 316 is arranged in two columns. The two columns of the first metallized array via structure 316 are located on both sides of the first inner conductor 314 and the second inner conductor 315, respectively. The two columns of the first metallized array via structure 316, together with the top metal plate 310, the middle metal plate 320 and the bottom metal plate 330, form the substrate integrated coaxial line structure of the feed port structure 30, and are arranged correspondingly to the substrate integrated coaxial line structure of the multiplex feed network structure 20.

[0070] In this embodiment, the diameter of the electrically conductive via is 0.3 mm, and the spacing between adjacent electrically conductive vias is 0.4 mm.

[0071] In this embodiment, the power supply port structure 30 is manufactured using a multilayer printed circuit board process, and the thickness of the power supply port structure 30 is the same as the thickness of the multiplex power supply network structure 20. The thickness of the multiplex power supply network structure 20 is adapted to the thickness of the radiator 10.

[0072] In this embodiment, the first monopole antenna 110 and the second monopole antenna 120 each have three circuit boards, each circuit board has a dielectric substrate 101, and the circuit boards are bonded together to form a whole by an adhesive process.

[0073] In this embodiment, the power supply port structure 30 is formed by bonding two multilayer printed circuit boards. Each printed circuit board includes three layers. The top metal layer of one printed circuit board forms the top metal plate 310 of the power supply port structure 30. A portion of the top metal layer of the other printed circuit board is removed to form a slotted structure and forms the bottom metal plate 330 of the power supply port structure 30 (as the outer conductor of the substrate integrated coaxial structure). In this embodiment, the controller is connected from the input port of the multiplexed power supply network structure 20 (specifically from the connection branch between the power supply port structure 30 and the numerically controlled power source) to couple out a portion of the reflected power. The coupled reflected power is detected to form detection information, which is then input to the controller. The controller is a programmable controller. When the reflected power information (i.e. detection information) coupled from the feed port structure 30 is input, it sends specific control commands to the numerically controlled power source as needed, so that the numerically controlled power source changes the microwave frequency and power fed into the feed port structure 30, and adjusts the radiation intensity of the first monopole antenna 110 and the second monopole antenna 120, thereby adjusting the size and shape of the ablation area on both sides of the antenna.

[0074] This application reduces the reflected power and weakens the "tail effect" (achieved through self-cancellation) by connecting the controller from the input port (i.e., the waveguide inner conductor 311) of the multiplexed feed network structure 20. The related structure of the "water circulation cooling system" in the existing structure can be omitted, which simplifies the overall structure of the medical microwave ablation antenna and reduces the manufacturing and maintenance costs of the medical microwave ablation antenna.

[0075] In this embodiment, the controller is connected to a human-machine interface, which allows doctors using the ablation antenna to adjust the desired shape of the antenna's ablation area according to clinical needs. The controller maps the adjusted parameters to power and frequency information and reports it to the digitally controlled power source, thereby enabling arbitrary adjustment of the shape of the antenna's ablation area as needed.

[0076] Example 2 like Figure 9 As shown, the difference between this embodiment and embodiment 1 is that a second metallized array via structure 317 is also formed on the waveguide outer conductor 312 in this embodiment. The second metallized array via structure 317 is a shielding via. The second metallized array via structure 317 is located on both sides of the first metallized array via structure 316 and is disposed along the outer edge of the power supply port structure 30.

[0077] When the CNC power source receives high power input through the power supply port structure 30, if the power supply port structure 30 itself does not take any shielding measures, microwave radiation will also be generated at its corners, causing power leakage, wasting power and reducing efficiency. By setting the second metallized array through-hole structure 317, power leakage can be reduced.

[0078] In this embodiment, the diameter of the shielding via is 0.3 mm, and the distance between adjacent shielding vias is the same as the distance between adjacent electrical wall vias, which is 0.4 mm.

[0079] By keeping the aperture diameter and spacing of the shielding via 317 and the electric wall via 316 the same, the two structures can be equivalent to the same electric wall, avoiding additional discontinuities when they are connected and introducing new microwave parasitic parameters.

[0080] In this embodiment, the bottom metal plate 330 is a whole metal plate with a slotted structure. The slotted structure is used to prevent the input power from being directly coupled to the grounded bottom metal plate 330.

[0081] In this embodiment, the slotted structure is a circular slot 331 with a diameter of 2mm. The circular slot 331 is coaxially arranged with the metallized transition through hole 313.

[0082] In addition to blocking unwanted coupling paths, the circular slot 331 has a further function: The circular slot 331 is coaxially connected to the metallized transition via 313, and its radius is slightly larger than the diameter of the metallized transition via 313. This makes the circular slot 331 and the metallized transition via 313 form a coaxial circular hole structure. The circular slot 331 and the metallized transition via 313 are filled with dielectric material, thus the whole structure is equivalent to a parallel plate capacitor with inner and outer conductors composed of concentric metal circles and a dielectric material filling the middle. By using electromagnetic full-wave simulation tools and computer-aided design tools to optimize the radius of the circular slot 331, a capacitor of appropriate size can be optimized to precisely offset the parasitic inductance introduced by the metallized transition via 313. With the parasitic inductance offset, the matching of the multiplexed feed network structure 20 can be more accurate, the frequency selectivity can be improved, and the unilateral nature of radiation can be further improved. Simultaneously, by reducing the influence of parasitic parameters that are easily altered by the external environment, the overall environmental stability of the device of this invention can also be further improved.

[0083] Example 3 like Figure 10As shown, the difference between this embodiment and embodiment 2 is that the slotted structure in this embodiment is a rectangular slot 332. The rectangular slot 332 is set in correspondence with the rectangular structure slot forming the coplanar waveguide. Specifically, the projection of the rectangular structure slot forming the coplanar waveguide on the bottom metal plate 330 coincides with the rectangular slot 332.

[0084] The main advantage of rectangular groove 332 is that it is easy to manufacture.

[0085] The outer waveguide conductor 312 of the top metal plate 310 has a rectangular mounting slot for the inner waveguide conductor 311. Setting the slotted structure on the bottom metal plate 330 to correspond in size and shape to the rectangular mounting slot on the top metal plate 310 facilitates rapid mass production. Meanwhile, the process of creating circular slots 331 may vary in precision, cost, and time among different printed circuit board manufacturers. The rectangular slot 332, while ensuring the basic function of avoiding power waste, offers advantages in processing time and cost compared to the circular slot 331. This allows the solution to better meet the requirements of "simplified process and structure, low manufacturing cost," and to achieve the advantages of "simple design, easy mass production, and low cost."

[0086] The above description is merely a preferred embodiment of the present invention and does not limit the scope of patent protection of the present invention. Any equivalent structural transformations made based on the description and drawings of the present invention, whether directly or indirectly applied to other related technical fields, are similarly included within the scope of protection of the present invention.

Claims

1. A medical microwave ablation antenna, characterized in that, This includes the radiator, the multiplexed power supply network structure, and the controller; The radiator is a dual-frequency narrowband radiating antenna, and the radiator includes at least a first monopole antenna and a second monopole antenna, with the reflector of the first monopole antenna and the reflector of the second monopole antenna arranged opposite to each other; The multiplexed feed network structure includes at least a first feed network branch and a second feed network branch. The first feed network branch is connected to the first monopole antenna and feeds the first monopole antenna, and the second feed network branch is connected to the second monopole antenna and feeds the second monopole antenna. The controller is connected to the multiplexed power supply network structure. The controller is also used to control the frequency and power of the wave emitted by the digitally controlled power source, so as to regulate the radiation intensity of the first monopole antenna and the second monopole antenna, and thus regulate the size and shape of the ablation region on both sides of the antenna.

2. The medical microwave ablation antenna as described in claim 1, characterized in that, The radiator is a dual-frequency narrowband radiating antenna manufactured using a multilayer printed circuit board process. The first monopole antenna and the second monopole antenna have the same external dimensions and center frequencies at opposite ends of the 2.4GHz~2.5GHz frequency band, respectively. The first monopole antenna and the second monopole antenna share a single layer of metal reflector.

3. A medical microwave ablation antenna as described in claim 1, characterized in that, A first protective layer is formed outside the radiator, and the first protective layer is a non-conductive, corrosion-resistant heat-shrinkable material. The multiplex power supply network structure is manufactured using a multilayer printed circuit board process. The multiplexed power supply network structure has a second protective layer formed on its exterior. The second protective layer is a non-conductive, corrosion-resistant heat-shrinkable material.

4. A medical microwave ablation antenna as described in claim 1, characterized in that, The multiplexed power supply network structure includes at least one impedance transformer and three quarter-wavelength impedance transformers. The impedance transformers are connected in series with the three quarter-wavelength impedance transformers, and all of them are substrate-integrated coaxial structures.

5. A medical microwave ablation antenna as described in claim 1, characterized in that, The multiplexed power supply network structure also includes a power supply port structure; The power supply port structure is used to connect to a digitally controlled power source; The first feed network branch and the second feed network branch are respectively connected to the feed port structure; The power emitted by the numerically controlled power source is split into the first feed network branch and the second feed network branch through the feed port structure, and then transmitted to the first monopole antenna and the second monopole antenna through the first feed network branch and the second feed network branch respectively.

6. A medical microwave ablation antenna as described in claim 5, characterized in that, The power supply port structure includes a top metal plate, a middle metal plate, and a bottom metal plate; The top metal plate forms a coplanar waveguide, which includes a waveguide inner conductor and a waveguide outer conductor arranged coplanarly. The outer end of the waveguide inner conductor away from the waveguide outer conductor is the input end, which is used to connect to a digitally controlled power source. The inner end of the waveguide inner conductor near the waveguide outer conductor has a metallized transition via. A first inner conductor is formed between the top metal plate and the middle metal plate, and a second inner conductor is formed between the middle metal plate and the bottom metal plate; One end of the first inner conductor and the second inner conductor are electrically connected through the metallized transition via; The other ends of the first inner conductor and the second inner conductor are respectively connected to the first feed network branch and the second feed network branch.

7. A medical microwave ablation antenna as described in claim 6, characterized in that, A first metallized array via structure is also formed on the outer conductor of the waveguide. The first metallized array via structure is arranged in two columns. The two columns of the first metallized array via structure are located on both sides of the first inner conductor and the second inner conductor, respectively. The two columns of the first metallized array via structure, together with the top metal plate, the middle metal plate and the bottom metal plate, form the substrate integrated coaxial line structure of the feed port structure, and are arranged correspondingly to the substrate integrated coaxial line structure of the multiplex feed network structure.

8. A medical microwave ablation antenna as described in claim 7, characterized in that, A second metallized array via structure is also formed on the outer conductor of the waveguide, and the second metallized array via structure is a shielding via. The second metallized array via structure is located on both sides of the first metallized array via structure and is disposed along the outer edge of the power supply port structure.

9. A medical microwave ablation antenna as described in claim 8, characterized in that, The bottom metal plate is provided with a slotted structure, which is used to prevent the input power from being directly coupled to the grounded bottom metal plate. The slotted structure is a circular slot or a rectangular slot: When the slotted structure is a circular slot, the circular slot is coaxially arranged with the metallized transition through hole and the bottom metal plate is a complete metal plate; When the slotted structure is a rectangular slot, the rectangular slot is provided in correspondence with the rectangular structure slot that forms a coplanar waveguide.

10. A medical microwave ablation antenna as described in claim 5, characterized in that, The controller is connected from the feed port structure of the multiplexed feed network structure to couple out a portion of the reflected power. The coupled reflected power is detected to form detection information, which is used to input the controller. The controller is a programmable controller. When the reflected power information coupled from the feed port structure is input, it sends specific control commands to the numerically controlled power source as needed, so that the numerically controlled power source changes the microwave frequency and power fed into the feed port structure.

Images