Annular radiator array suitable for heating shanks of human body

Abstract

The invention discloses an annular radiator array suitable for heating a shank of a human body. The annular radiator array comprises a plurality of microstrip radiator units, wherein the plurality of microstrip radiator units are rotationally and symmetrically arranged; the microstrip radiator unit comprises a dielectric substrate, a slotted rectangular metal patch, a rectangular metal patch, a coaxial feed port and a feed probe; wherein the dielectric substrate is provided with a first surface and a second surface which are opposite to each other, the slotted rectangular metal patch serves as a radiator and is arranged on the first surface, the rectangular metal patch serves as a ground plane and is arranged on the second surface, and the coaxial feed port is arranged on the second surface and is arranged on the first surface. And the coaxial feed port is used as an energy input port and penetrates through the dielectric substrate through a feed probe, and the feed probe is connected with the slotted rectangular metal patch. The device can perform focused heating on human calf tissues, and is applied to the fields of medical treatment and physical therapy.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to an annular radiator array suitable for heating the calf of a human body. Background Art

[0002] Microwave heating therapy is a treatment method that uses microwaves to produce biological thermal effects on human tissues and performs local or whole-body heating on the lesion site. The principle is to heat the lesion tissue to an effective treatment temperature range, thereby slowing down the division rate of lesion cells and accelerating their death. Local heating can also be used as an adjuvant therapy for radiotherapy and chemotherapy. This scheme has been widely studied and applied in clinical treatment. A large number of studies have shown that hyperthermia combined with radiotherapy or chemotherapy can improve the local control rate of tumors and the survival rate of patients. In addition, studies have also shown that local or whole-body heating of lesion tissues can effectively improve human immunity, microcirculation and metabolic rate. There are two main ways to heat human tissues with microwave energy: internal heating and external heating. Internal heating directly ablates the lesion tissue by implanting a probe-type radiator into the human tissue and using the thermal effect generated by its radiation, but this method can cause damage to the patient. In contrast, external heating uses a radiator placed outside the human body to penetrate the radiated microwave energy into the lesion tissue to achieve heating, avoiding trauma to the patient. Focused radiator is a more effective extracorporeal hyperthermia method. Through an array of extracorporeal microwave radiators, microwave energy is focused on the diseased tissue for local heating, thereby effectively improving energy utilization efficiency.

[0003] At present, most radiator array focusing methods are not suitable for energy focusing design in complex environments. In particular, for the application environment of heating the lower leg of the human body, traditional methods cannot consider the complex multipath effect in the cavity. Summary of the invention

[0004] The purpose of the present invention is to provide an annular radiator array suitable for heating the lower leg of a human body, and to implement focused heating on the lower leg of a human body by utilizing the designed annular radiator array.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A ring radiator array suitable for heating the lower leg of a human body, comprising a plurality of microstrip radiator units; wherein the plurality of microstrip radiator units are arranged rotationally symmetrically;

[0007] The microstrip radiator unit includes a dielectric substrate, a slotted rectangular metal patch, a rectangular metal patch, a coaxial feeding port and a feeding probe; wherein the dielectric substrate has a first surface and a second surface opposite to each other, the slotted rectangular metal patch is used as a radiator and is arranged on the first surface, the rectangular metal patch is used as a ground plane and is arranged on the second surface, the coaxial feeding port is arranged on the second surface, the coaxial feeding port passes through the dielectric substrate through a feeding probe, and the feeding probe is welded to the slotted rectangular metal patch.

[0008] Furthermore, the material of the dielectric substrate is a dielectric material.

[0009] Furthermore, the slotted rectangular metal patch is etched on the first surface of the dielectric substrate, and the slotted rectangular metal patch is slotted on the long side of the original rectangular metal patch.

[0010] Furthermore, the rectangular metal patch is etched on the second surface to serve as a ground plane.

[0011] Furthermore, the input impedance of the coaxial feeding port is 50Ω, and the feeding probe is welded to the slotted rectangular metal patch.

[0012] Furthermore, the number of the microstrip radiator units is set to eight.

[0013] Furthermore, it also includes a cylindrical metal reflector plate, a cylindrical acrylic plate, and a cylindrical port metal reflector plate; a plurality of microstrip radiator units are rotationally symmetrically arranged to form a cavity, the cylindrical metal reflector plate is arranged on the outside of the cavity, the cylindrical acrylic plate is arranged on the inside of the cavity, and the cylindrical port metal reflector plate is arranged at both ends of the cavity.

[0014] Furthermore, the cylindrical metal reflector has a cylindrical radius of 200-300 mm and a cylindrical height of 300-500 mm, and is used to shield the microwave energy in the cavity from radiating outward.

[0015] Furthermore, the cylindrical acrylic plate has a cylindrical radius of 150 to 250 mm and a cylindrical height of 300 to 500 mm, and is used to spatially isolate the calf and the annular radiator array.

[0016] Furthermore, the cylindrical port reflector is a toroidal metal plate, which is used to fix the annular radiator array and reduce the radiation of microwave energy to the two ends of the cavity, thereby improving the electromagnetic compatibility of the system.

[0017] Furthermore, the coaxial feeding ports of each microstrip radiator unit are simultaneously excited with a set excitation distribution to implement focused heating of the calf tissue.

[0018] Furthermore, the set incentive distribution is determined by the following method:

[0019] Placing a calf model in a cavity formed by an annular radiator array; wherein the calf model comprises a skin layer, a muscle layer and a bone layer connected in sequence from outside to inside;

[0020] The electric field of each microstrip radiator unit in the calf model area is extracted and the generalized power transfer function is constructed;

[0021] The extremum of the generalized power transfer function is optimized by using an eigenvalue equation to obtain an optimal excitation distribution, and the optimal excitation distribution is used as the set excitation distribution.

[0022] The beneficial effects of the present invention are:

[0023] The present invention proposes an annular radiator array suitable for heating human calf tissue, and its operating frequency is 433MHz. By utilizing the penetrability of 433MHz microwaves, the high dielectric constant characteristics of calf tissue and the optimal excitation distribution of the annular radiator array, the annular radiator array can effectively focus the radiated microwave energy into the calf tissue to achieve focused heating, which is beneficial to reducing the outward radiation of microwave energy in the cavity, and improving the energy utilization efficiency and electromagnetic compatibility of the microwave heating system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the front structure of a microstrip radiator unit according to an embodiment of the present invention is shown; wherein, (a) is the first surface of the microstrip radiator; (b) is the second surface of the microstrip radiator; and (c) is the side surface of the microstrip radiator.

[0025] Figure 2 A schematic structural diagram of a calf model according to an embodiment of the present invention is shown.

[0026] Figure 3 A schematic structural diagram of a ring radiator array according to an embodiment of the present invention is shown.

[0027] Figure 4 A schematic diagram of the use status of a ring radiator array according to an embodiment of the present invention is shown.

[0028] Figure 5 The S11 simulation result diagram of the microstrip radiator unit and the ring radiator array according to the embodiment of the present invention is shown.

[0029] Figure 6 A diagram showing the electric field energy distribution result of the calf transverse section after the calf is loaded with an annular radiator array according to an embodiment of the present invention.

[0030] Figure 7A graph showing the specific absorption rate (SAR) distribution result of the calf transverse section after the calf is loaded with an annular radiator array according to an embodiment of the present invention.

[0031] Figure 8 A diagram showing the electric field energy distribution result in the longitudinal section of the calf after the calf is loaded with an annular radiator array according to an embodiment of the present invention.

[0032] Fig. 9 A graph showing the specific absorption rate (SAR) distribution result of the longitudinal section of the calf after the calf is loaded with an annular radiator array according to an embodiment of the present invention.

[0033] Reference numerals:

[0034] 1. Dielectric substrate; 2. Slotted rectangular metal patch; 3. Feed probe; 4. Rectangular metal patch; 5. Coaxial feeding port; 6. Skin layer; 7. Muscle layer; 8. Bone layer; 9. Outer cylindrical metal reflector; 10. Inner cylindrical acrylic plate; 11. Microstrip radiator unit; 12. Outer cylindrical port metal reflector; 13. Calf model; 14. Microstrip radiator array DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0036] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The specific implementation of the present invention is further described in detail below in conjunction with the drawings and examples.

[0039] An embodiment of the present invention provides an annular radiator array suitable for heating the calf of a human body, and the annular radiator array suitable for heating the calf of a human body comprises a plurality of microstrip radiator units 11; wherein the plurality of microstrip radiator units 11 are rotationally symmetrically arranged.

[0040] For example, the microstrip radiator units 11 may be arranged in eight units, and the structure after the rotational symmetry is as follows: Figure 3 and Figure 4 , adjacent microstrip radiator units 11 are connected, and the finally formed annular radiator array is a regular octagonal shape.

[0041] like Figure 1 and Figure 2 As shown, the microstrip radiator unit 11 includes a dielectric substrate 1, a slotted rectangular metal patch 2, a feeding probe 3, a rectangular metal patch 4 and a coaxial feeding port 5; wherein the dielectric substrate 1 has a first surface and a second surface opposite to each other, the slotted metal patch 2 is used as a radiator and is arranged on the first surface, the first surface is the surface facing the calf during the heating process, and the second surface is the surface facing away from the calf, the slotted rectangular metal patch 2 is provided with a slotted structure in the long side direction, the rectangular metal patch 4 is provided on the second surface as a ground plane, the coaxial feeding port 5 is provided on the second surface, the coaxial feeding port passes through the dielectric substrate 1 through the feeding probe 3, and the feeding probe 3 is connected to the slotted rectangular metal patch 2.

[0042] In this embodiment, the slotted rectangular metal patch 2 of the microstrip radiator unit 11 is designed with a slotted structure on its narrow side, which can reduce the size of the microstrip radiator unit and facilitate the miniaturization of the entire microwave heating device. The microstrip radiator unit also has the advantages of compact structure, high integration, small size and high carrying power.

[0043] In some embodiments, a slotted rectangular metal patch 2 is etched on the first surface of the dielectric substrate 1, and a slotted structure is formed on the long sides of the slotted rectangular metal patch 2 to obtain a wider radiation bandwidth, and a rectangular metal patch 4 is etched on the second surface of the dielectric substrate 1, and the size of the rectangular metal patch 4 is the same as the size of the dielectric substrate 1.

[0044] In some embodiments, the material of the dielectric substrate is similar to other common dielectric materials such as FR4 board, which has the advantages of high temperature resistance, low dielectric constant and low dielectric loss, super strong mechanical properties and good flame retardant properties, ensuring that the circuit board can work stably in various extreme and special environments. In this embodiment, the parameters of the material of the dielectric substrate are as follows: relative dielectric constant is 4.4, loss tangent is 0.02, and thickness is 10 mm.

[0045] In some embodiments, the input impedance of the coaxial feed port 5 is set to 50Ω, and the feed port is located 10 mm directly below the geometric center of the rectangular metal patch. The setting of the coaxial feed port 5 facilitates connection with the feed cable. A feed probe 3 is provided at the coaxial feed port 5, which penetrates the entire dielectric substrate 1 and is welded to the radiator (i.e., the slotted rectangular metal patch 2) on the first surface of the dielectric substrate 1. By setting the coaxial feed port 5, it is convenient to achieve connection and matching between the microstrip radiator unit and the coaxial feed cable, and reduce energy reflection on the coaxial feed cable.

[0046] In some embodiments, Figure 3 and Figure 4 As shown, the annular radiator array for heating the lower leg of a human body also includes: Figure 1 The annular radiator array 14 shown is composed of 8 microstrip radiator units arranged in rotational symmetry, a cylindrical metal reflector plate 9 arranged on the outside, a cylindrical acrylic plate 10 arranged on the inside, and an outer cylindrical port metal reflector plate 12.

[0047] In this embodiment, a cylindrical metal reflector plate 9 with a certain thickness is loaded on the outside of the annular radiator array 14 to shield the outward radiation of electromagnetic energy, and a cylindrical acrylic plate 10 with a certain thickness is loaded between the annular radiator array 14 and the calf model 13 to prevent direct contact between the calf and the annular radiator array.

[0048] Exemplarily, the cylindrical metal reflector plate 9 is arranged on the outside of the annular radiator array 14, with a height of 400 mm and a radius of 250 mm, so as to shield the microwave energy in the cavity formed by the annular radiator array 8 from radiating outward, thereby improving the microwave energy utilization efficiency and electromagnetic compatibility of the system during the calf heating process.

[0049] Exemplarily, the cylindrical acrylic plate 10 is located on the inner side of the annular radiator array 8, with a height of 400 mm and a radius of 200 mm, so as to achieve spatial isolation between the leg and the annular radiator array 8 and prevent the calf tissue from directly contacting the radiator array.

[0050] Exemplarily, the outer cylindrical port metal reflector 12 is located at both ends of the cylindrical cavity formed by the cylindrical metal reflector 9 and the cylindrical acrylic plate 10, so as to fix the annular radiator array 14, prevent the annular radiator array 14 from being damaged by external environmental factors, and reduce the radiation of cavity microwave energy to both ends.

[0051] In some embodiments, a calf model is also provided, and the calf model structure is as follows: Figure 2 As shown, it includes: a skin layer 6, a muscle layer 7, and a bone layer 8. During the design process, the calf model adopts a three-layer human tissue structure (skin, muscle and bone), and its dielectric constant and loss tangent are calculated by the public Cole-Cole dielectric model.

[0052] In this embodiment, the purpose of setting the calf model is to obtain the best excitation distribution of the annular radiator array.

[0053] In the microwave in vitro heating system, the microwave radiator array needs to be properly excited to maximize the transmission of microwave energy to the lesion tissue, thereby forming high-efficiency heating. For the optimization problem of microwave radiator array excitation distribution, the mainstream methods include time reversal method and modern intelligent optimization algorithms, such as genetic algorithm, particle swarm algorithm, ant colony algorithm, etc. However, these algorithms use iterative calculations, which are prone to form local optimal solutions or can only approximate the optimal solution.

[0054] Based on this, the present invention designs a calf model. Based on the calf model, a maximum power transmission method is adopted to quickly obtain the optimal excitation distribution of the array radiator by solving the eigenvalue equation to obtain the maximum microwave heating efficiency.

[0055] Specifically, a calf model is placed in a cavity formed by a ring radiator array; wherein the calf model includes a skin layer, a muscle layer, and a bone layer connected from the outside to the inside; the electric field of each microstrip radiator unit in the calf model area is extracted, and a generalized power transfer function is constructed; the extremum of the generalized power transfer function is optimized using the eigenvalue equation to obtain the optimal excitation distribution, and the optimal excitation distribution is used as the set excitation distribution. The coaxial feeding ports of each microstrip radiator unit are simultaneously excited with the set excitation distribution to implement focused heating on the calf tissue.

[0056] like Figure 5As shown, the return loss S11 of the microstrip radiator unit and the annular radiator array, that is, the ratio of the port reflected signal power to the input power of the coaxial feeding port 5 of the microstrip radiator, is lower than -10dB at 433MHz, that is, the annular radiator array involved in the present invention can work effectively at a frequency of 433MHz.

[0057] like Figure 6 , which is a diagram showing the electric field distribution results of the annular radiator array involved in an embodiment of the present invention in the transverse cross section of a calf model, achieving a focusing effect of the electric field energy on the calf tissue.

[0058] like Figure 7 , which is a graph showing the specific absorption rate (SAR) distribution result of the annular radiator array involved in an embodiment of the present invention in the transverse cross section of a calf model, achieving a focusing effect of the electric field energy on the calf tissue.

[0059] like Figure 8 , which is a diagram showing the electric field distribution results of the annular radiator array involved in an embodiment of the present invention in the longitudinal section of a calf model, achieving a focusing effect of the electric field energy on the calf tissue.

[0060] like Fig. 9 , which is a graph showing the specific absorption rate (SAR) distribution result of the annular radiator array involved in an embodiment of the present invention in the longitudinal section of a calf model, achieving a focusing effect of the electric field energy on the calf tissue.

[0061] Therefore, the present invention uses the generalized maximum power transfer efficiency method to calculate the optimal excitation distribution of the radiator array. The advantage of this method is that by reasonably calculating the excitation distribution of the radiator array, the microwave energy radiated by the radiator array can be transmitted to the human calf tissue area to the maximum extent, thereby maximizing the microwave energy utilization efficiency and electromagnetic compatibility of the microwave in vitro heating system, and effectively reducing the system power consumption.

[0062] The above implementation modes are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The patent protection scope of the present invention should be defined by the claims.

Claims

1. A ring radiator array suitable for heating the lower leg of a human body, characterized in that: comprising a plurality of microstrip radiator units; wherein the plurality of microstrip radiator units are arranged rotationally symmetrically; The microstrip radiator unit includes a dielectric substrate, a slotted rectangular metal patch, a rectangular metal patch, a coaxial feeding port and a feeding probe; wherein the dielectric substrate has a first surface and a second surface opposite to each other, the slotted rectangular metal patch is used as a radiator and is arranged on the first surface, the rectangular metal patch is used as a ground plane and is arranged on the second surface, the coaxial feeding port is arranged on the second surface, the coaxial feeding port is used as an energy input port, and passes through the dielectric substrate through a feeding probe, and the feeding probe is welded to the slotted rectangular metal patch.

2. The annular radiator array suitable for heating the lower leg of a human body as claimed in claim 1, characterized in that: The material of the dielectric substrate is a dielectric material.

3. The annular radiator array suitable for heating the lower leg of a human body as claimed in claim 1, characterized in that: The slotted rectangular metal patch is etched on the first surface of the dielectric substrate.

4. The annular radiator array suitable for heating the lower leg of a human body according to claim 1, characterized in that: The rectangular metal patch is etched on the second surface of the dielectric substrate.

5. The annular radiator array suitable for heating the lower leg of a human body according to claim 1, characterized in that: The input impedance of the coaxial feeding port is 50Ω, and the feeding probe is welded to the slotted rectangular metal patch.

6. The annular radiator array suitable for heating the lower leg of a human body according to claim 1, characterized in that: The number of the microstrip radiator units is eight.

7. The annular radiator array suitable for heating the lower leg of a human body according to claim 1, characterized in that: It also includes a cylindrical metal reflector plate, a cylindrical acrylic plate and a cylindrical port metal reflector plate; a plurality of microstrip radiator units are rotationally symmetrically arranged to form a cavity, the cylindrical metal reflector plate is arranged on the outside of the cavity, the cylindrical acrylic plate is arranged on the inside of the cavity, and the cylindrical port metal reflector plate is arranged at both ends of the cavity.

8. The annular radiator array suitable for heating the lower leg of a human body as claimed in claim 7, characterized in that: The cylindrical metal reflector has a cylindrical radius of 200-300 mm and a cylindrical height of 300-500 mm, and is used to shield microwave energy in the cavity from radiating outward.

9. The annular radiator array suitable for heating the lower leg of a human body according to claim 7, characterized in that: The cylindrical acrylic plate has a cylindrical radius of 150 to 250 mm and a cylindrical height of 300 to 500 mm, and is used for spatially isolating the calf and the annular radiator array.

10. The annular radiator array suitable for heating the lower leg of a human body according to claim 7, characterized in that: The cylindrical surface port metal reflector is used to fix the annular radiator array and reduce the radiation of microwave energy to the two ends of the cavity.

11. The annular radiator array suitable for heating the lower leg of a human body according to claim 1, characterized in that: The coaxial feeding ports of each microstrip radiator unit are excited simultaneously by using a set excitation distribution to implement focused heating.

12. The annular radiator array suitable for heating the lower leg of a human body according to claim 11, characterized in that: The set excitation distribution is determined by the following method: Placing a calf model in a cavity formed by an annular radiator array; wherein the calf model comprises a skin layer, a muscle layer and a bone layer connected in sequence from outside to inside; The electric field of each microstrip radiator unit in the calf model area is extracted and the generalized power transfer function is constructed; The extremum of the generalized power transfer function is optimized by using an eigenvalue equation to obtain an optimal excitation distribution, and the optimal excitation distribution is used as the set excitation distribution.

Images