A ring array antenna applied to lower limb foot knee physiotherapy heating
By designing a ring array antenna structure, combined with a dielectric substrate, coaxial feed, and metal patches, the problems of large size, poor penetration, and non-adjustable power in existing microwave heating equipment have been solved. This has resulted in a smaller size, stronger penetration, and adjustable power microwave heating effect, which can meet the needs of different human body sizes.
Patent Information
- Application Number
- CN202422069137.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2034-08-26
AI Technical Summary
In the existing technology, the antenna design of microwave heating physiotherapy equipment has problems such as large size, insufficient penetration and non-adjustable power, making it difficult to meet the adaptability needs of different human body sizes.
It adopts a ring array antenna structure composed of multiple sub-microstrip array antennas, combined with dielectric substrate, coaxial feed port and metal patch design to form a cylindrical structure. Acrylic plate is used to isolate the human body from the antenna. The operating frequency is 433MHz, the antenna element is less than 1/4 wavelength, and 50Ω coaxial feed is used to control the input power.
It achieves microwave heating effects with smaller size, stronger penetration and adjustable power, adapts to the microwave heating needs of different human body sizes, and improves the practicality and safety of the equipment.
Smart Images
Figure CN224683364U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of medical equipment, and in particular relates to a ring array antenna for lower limb foot and knee physiotherapy heating. Background Technology
[0002] With the advancement of society, people are paying increasing attention to their health, and the field of physiotherapy is constantly exploring new methods. Using microwave energy to heat the calves can effectively promote blood circulation, enhance the body's immune system, and accelerate microcirculation. Based on this understanding of the therapeutic advantages, the acceptance of microwave heating therapy in the rehabilitation medicine community is gradually increasing. Furthermore, using the thermal effect generated by electromagnetic energy to treat soft tissues can relieve chronic pain, accelerate postoperative recovery, and promote health and wellness.
[0003] Antennas are a crucial component of wireless systems; wireless systems and devices that rely on electromagnetic waves to transfer heat all depend on antennas. Antennas convert guided waves on transmission lines into free-space electromagnetic waves and concentrate radiated energy into directional radiation. Many authors have conducted theoretical and experimental research on microwave hyperthermia devices. Several hyperthermia therapies have been studied, including local hyperthermia, superficial hyperthermia, and deep hyperthermia, and also categorized as external and internal hyperthermia. Different array antenna structures have also been explored, such as planar array antennas, elliptical arrays, and ring arrays. Different design schemes can be selected according to different situations. Summary of the Invention
[0004] This invention provides a ring array antenna for lower limb foot and knee physiotherapy heating, which forms an electric field energy distribution inside a calf model. To achieve the above objective, the technical solution adopted by this invention is: a cylindrical structure composed of multiple sub-microstrip array antennas rotated symmetrically; wherein the sub-microstrip array antenna includes a dielectric substrate, a coaxial feed port, and a metal patch; the surface of the dielectric substrate is provided with at least one upward-facing E-shaped slot along the vertical axis, and the metal patch is installed along the slot position, with a rectangular shape having an E-shaped slot, adapted to the slot of the dielectric substrate; the coaxial feed port is located at the bottom of the dielectric substrate, and is a structure in which a circular hole is drilled in the bottom metal patch and a probe is inserted.
[0005] As an improvement, the sub-microstrip array antenna is provided with eight antennas, forming a ring array antenna with a regular octahedral barrel structure.
[0006] As an improvement, the dielectric substrate is made of flame-retardant FR-4 material and is rectangular in shape.
[0007] As an improvement, the length, width, and thickness of the rectangle are 450-650mm, 190-350mm, and 5-20mm, respectively, and preferably, the length, width, and thickness are 500mm, 250mm, and 10mm, respectively.
[0008] As an improvement, the surface metal patches are used as radiators. Two rectangular metal patches are etched on the surface of a dielectric substrate. The ring array antenna consists of eight microstrip subarray antennas, with a total of 16 rectangular metal patches serving as the radiator array.
[0009] As an improvement, the coaxial power supply of the coaxial power supply port is 50Ω, and the port is located 10±3mm directly below the center of the metal patch, preferably 10mm directly below.
[0010] As an improvement, the structure of the ring array antenna operates at a frequency of 433MHz, and the antenna element size is less than 1 / 4 of the operating wavelength.
[0011] As an improvement, an acrylic sheet is also included. The acrylic sheet has a cylindrical structure and is located between the ring array antenna and the lower leg to prevent the two from making direct contact.
[0012] As an improvement, the radius of the cylindrical surface of the acrylic sheet is 120-250mm, preferably 200mm.
[0013] Beneficial effects: The ring array antenna for calf heating proposed in this invention, while meeting the frequency band requirements for microwave heating therapy, features a smaller antenna size. The ring array antenna structure operates at 433MHz, with antenna element size less than 1 / 4 of the operating wavelength, exhibiting strong penetration, smaller size, and adjustable power.
[0014] The loop array antenna in this invention operates at 433MHz. The antenna element adopts an "E"-shaped microstrip antenna structure, which has a wide operating frequency band to accommodate the impact of different sized human lower legs on the antenna's performance. The "E"-shaped microstrip antenna element uses a 50Ω coaxial feed, which facilitates control of the input power and improves the practicality of the loop array antenna. This loop array antenna has advantages such as strong penetration, smaller size, and adjustable power. Attached Figure Description
[0015] Figure 1 This is a front view of an antenna unit of a ring array antenna used for lower limb foot and knee physiotherapy heating, according to Embodiment 1 of this utility model.
[0016] Figure 2 This is a schematic diagram of the lower leg model structure of a ring array antenna for lower limb foot and knee physiotherapy heating, as described in Embodiment 1 of this utility model.
[0017] Figure 3 This is a three-dimensional structural schematic diagram of a ring array antenna used for lower limb foot and knee physiotherapy heating, according to Embodiment 1 of this utility model.
[0018] Figure 4 This is a three-dimensional structural schematic diagram of the ring array antenna and the calf model used for calf heating in Embodiment 1 of this utility model.
[0019] Figure 5 This is a schematic diagram of the S-parameters of the antenna element and the ring array antenna in Embodiment 2 of this utility model.
[0020] Figure 6 This is a diagram showing the distribution of the transverse electric field energy inside the calf of the ring array antenna in Embodiment 2 of this utility model.
[0021] Figure 7 This is a diagram showing the longitudinal electric field energy distribution inside the calf of the ring array antenna in Embodiment 2 of this utility model.
[0022] In the figure: 1. Dielectric substrate; 2. Metal patch; 3. Coaxial feed port; 4. Skin simulation layer; 5. Muscle simulation layer; 6. Bone simulation layer; 8. Ring array antenna; 7. Acrylic plate; 9. Lower leg simulation model. Detailed Implementation
[0023] The specific embodiments of this utility model will be described in further detail below with reference to the examples. These examples are used to illustrate this utility model, but are not intended to limit its scope.
[0024] A ring array antenna for lower limb foot and knee physiotherapy heating is disclosed. The ring array antenna comprises a cylindrical structure composed of multiple sub-microstrip array antennas arranged in a rotational symmetry. Each sub-microstrip array antenna includes a dielectric substrate, a coaxial feed port, and a metal patch. At least one upward-facing E-shaped slot is provided on the surface of the dielectric substrate along the vertical axis. The metal patch is mounted along the slot and is rectangular in shape with the E-shaped slot, which is adapted to the slot of the dielectric substrate. The coaxial feed port is located at the bottom of the dielectric substrate and is constructed by drilling a circular hole in the bottom metal patch and inserting a probe.
[0025] In this utility model, the microstrip array antenna is preferably eight in number, and the metal patch is a rectangle with an "E"-shaped slot to broaden the antenna's operating bandwidth and reduce its size. The preferred metal patch is copper foil.
[0026] The dielectric substrate is made of flame-retardant FR-4 material with a dielectric constant of 4.4 and a loss tangent of 0.02.
[0027] Furthermore, a 50Ω coaxial feed port is soldered to the bottom of the dielectric substrate of the ring array, located 10mm directly below the center of the metal patch. A probe within this port penetrates the entire dielectric substrate to directly contact the metal radiating patch. This configuration allows for individual control of the antenna element excitation, facilitating better matching between the antenna and the feed line and reducing port energy reflection. Example 1
[0028] See Figure 1 As shown, the ring array antenna includes a dielectric substrate 1. The dielectric substrate is made of flame-retardant FR4 board or other common materials. It is rectangular with a length, width and thickness of 450-650mm, 190-350mm and 5-20mm, respectively. Preferably, the length, width and thickness are 500mm, 250mm and 10mm, respectively.
[0029] Furthermore, the metal patch 2 is used as a radiating surface and is installed on a slotted position on one side of the surface of the dielectric substrate. The copper-clad structure on the bottom surface of the substrate is the same size as the dielectric substrate and is used as a ground plane. A 50Ω coaxial feed port 3 is soldered to the bottom of the dielectric substrate. The port is located 10±3mm directly below the center of the metal patch, preferably 10mm directly below. Example 2
[0030] This invention proposes a structure and optimization of a ring array antenna for calf heating. It mainly consists of two parts: the ring array antenna is formed by eight dielectric substrates, one surface of each substrate, to form a regular octahedral cavity structure, with two radiating metal patches on each surface, consisting of 16 units.
[0031] Furthermore, in this embodiment, the ring array antenna is composed of 16 "E"-shaped microstrip antenna elements placed in a rotationally symmetrical manner, with an octagonal cavity structure in appearance. The "E"-shaped microstrip antenna element consists of a dielectric substrate 1, an "E"-shaped metal patch 2, and a coaxial feed port 3.
[0032] See Figure 2 As shown, this is a simulation model of the lower leg, consisting of a skin simulation layer 4, a muscle simulation layer 5, and a bone simulation layer 6, from the outside in. The diameter of the entire model gradually decreases from top to bottom to achieve a realistic simulation of human anatomy. The relative permittivity and loss tangent of the three layers were calculated using the Cole-Cole dielectric model, reflecting the realism of the simulation.
[0033] As a specific embodiment of this utility model, see [link / reference]. Figure 3As shown, it includes a ring array antenna, an acrylic plate, and a lower leg simulation model; the acrylic plate is an open structure of a cylindrical body; the lower leg simulation model is a three-layer electromagnetic simulation structure, wherein the acrylic plate 7 is located between the ring array antenna 8 and the lower leg simulation model 9, which is used for spatial isolation between the two to achieve the function of protecting the lower leg.
[0034] A cylindrical acrylic plate with an inner diameter of 200mm is placed inside the ring array to avoid direct contact between the array antenna and the calf, thus achieving spatial isolation between the calf and the ring array antenna. The calf simulation model is placed inside the cavity formed by the ring array antenna. In order to improve the realism of the electromagnetic simulation, the dielectric constant and loss tangent of the calf tissue are calculated using the publicly available Cole-Cole model.
[0035] See Figure 4 The diagram shown illustrates the usage status of the ring array antenna, including... Figure 2 The structure shown is a three-layer leg model, specifically the lower leg simulation model 9.
[0036] The ring array antenna provided by this invention can achieve microwave heating of the lower leg. The ring array antenna system for lower limb foot and knee physiotherapy heating mainly consists of four parts: ring array antenna, acrylic plate, and lower leg simulation model. The ring array antenna operates at 433MHz, and the antenna element adopts an "E"-shaped microstrip antenna structure, which has a wide operating frequency band to adapt to the impact of different sizes of human lower legs on the antenna's performance.
[0037] The "E"-type microstrip antenna element uses a 50Ω coaxial feed, which facilitates input power control and improves the practicality of the loop array antenna. This invention presents a loop array antenna for lower limb foot and knee physiotherapy heating, which has advantages such as strong penetration, smaller size, and adjustable power.
[0038] like Figure 5 As shown, the signal reflection coefficients of the antenna element and the loop array antenna during operation are as follows. When the loop array antenna operates at 433MHz, the reflection coefficient modulus (|S11|) is less than -10dB, indicating that the loop array antenna has good matching performance.
[0039] See Figure 6 As shown, the electric field distribution of the lateral cross section of the leg model is given when the loop array antenna is excited by a signal of the same amplitude and phase. This shows that the energy radiated by the loop array antenna can be effectively absorbed by the leg model and generate a thermal effect.
[0040] The aforementioned ring array antenna for lower limb foot and knee physiotherapy heating works as follows: A microwave signal is distributed to 16 equal-power channels and then excited in the same amplitude and phase manner by a ring array antenna of 16 elements. The ring array antenna radiates the injected power into an octagonal barrel-shaped cavity formed by eight microstrip sub-array antennas, interacting with a lower leg model placed within it. Because the bottom surface of the microstrip array antenna's dielectric substrate is a complete metal patch, it effectively shields the electromagnetic energy within the cavity, preventing outward radiation. The electromagnetic energy confined within the cavity can only interact with the lower leg, and based on the penetrating power of 433MHz electromagnetic energy, deep heating of the lower leg tissue is achieved.
[0041] The dielectric substrate material is a flame-retardant grade of FR4 or similar materials, which have certain flame-retardant properties. The dielectric substrate material used in this invention has a dielectric constant of 4.4 and a loss tangent of 0.02.
[0042] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.
Claims
1. A ring array antenna for lower limb foot and knee physiotherapy heating, characterized in that: It is a cylindrical structure composed of multiple sub-microstrip array antennas rotated symmetrically; wherein the sub-microstrip array antennas include a dielectric substrate, a coaxial feed port, and a metal patch; the surface of the dielectric substrate is provided with at least one upward-facing E-shaped slot along the vertical axis, and the metal patch is installed along the slot position, with a rectangular shape having an E-shaped slot, which is adapted to the slot of the dielectric substrate; the coaxial feed port is located at the bottom of the dielectric substrate, and is a structure in which a circular hole is drilled in the bottom metal patch and a probe is inserted; The sub-microstrip array antennas are provided in eight parts, forming a ring array antenna with a regular octahedral barrel structure; The surface metal patches are used as radiators. Two rectangular metal patches are etched on the surface of a dielectric substrate. The loop array antenna is composed of eight microstrip subarray antennas, with a total of 16 rectangular metal patches serving as the radiator array. The coaxial feed port is 50Ω, and the port is located 10±3mm directly below the center of the metal patch; the operating frequency of the loop array antenna is 433MHz, and the antenna element size is less than 1 / 4 of the operating wavelength.
2. The ring array antenna for lower limb foot and knee physiotherapy heating according to claim 1, characterized in that: The dielectric substrate is made of flame-retardant FR-4 material and is rectangular in shape.
3. The ring array antenna for lower limb foot and knee physiotherapy heating according to claim 2, characterized in that: The length, width, and thickness of the rectangle are 450-650mm, 190-350mm, and 5-20mm, respectively.
4. The ring array antenna for lower limb foot and knee physiotherapy heating according to claim 1, characterized in that: It also includes an acrylic sheet, which has a cylindrical structure and is located between the ring array antenna and the lower leg to prevent the two from making direct contact.
5. The ring array antenna for lower limb foot and knee physiotherapy heating according to claim 4, characterized in that: The radius of the cylindrical surface of the acrylic sheet is 120-250mm.