A DC high voltage isolator for microwave therapeutic apparatus

Abstract

The present invention relates to an isolator, in particular to a microwave therapeutic device DC high voltage isolator, belonging to the technical field of microwave isolators. The technical solution provided by the present invention includes a first isolation resonant cavity, a second isolation resonant cavity, a first antenna socket, a second antenna socket, and an insulating isolation ring. The first and second isolation resonant cavities are coaxially symmetrical open coupling hole cylindrical microwave cavities, the cylindrical cavity is made of metal aluminum, with a radius of R and a length of L; the first and second antenna sockets are N-type four-hole flange female sockets, the conductor coupling column diameter in the antenna socket is >3mm, and the length of the conductor coupling column placed in the resonant cavity is <20mm; the insulating isolation ring is made of cylindrical nylon material, the thickness of the middle insulating ring is <2mm, and the incident electric field obtains a voltage zero point at the insulating isolation ring. The present invention can realize a BF type design, realize isolation of DC and high voltage, prevent electric shock when the treatment probe contacts the human body, and at the same time effectively output microwave energy to achieve an effective treatment effect.

Description

Technical Field

[0001] The invention relates to the technical field of microwave isolators, and in particular to a direct current high voltage isolator for a microwave therapeutic apparatus. Background Art

[0002] Microwave therapeutic devices treat diseases mainly by consuming microwave energy to produce thermal effects, and use this heat to treat various diseases. Microwaves are emitted from the microwave therapeutic device, output to the treatment probe through a microwave cable, and intervene in the lesions of the patient's local tissue for treatment. According to the classification requirements for protection against electric shock of medical electrical equipment, the application part of the microwave therapeutic device must be a BF type device, that is, this device is suitable for the body surface and body cavity, but it must have an insulated contact with the patient. Most of the existing microwave therapeutic devices mainly use the BF type isolation design for the circuit part, but because the core microwave output components of the device have high power and high voltage, this type of design is complex and difficult to effectively isolate the DC high voltage, and there is a safety risk of leakage to the application part. Summary of the invention

[0003] The purpose of the embodiment of the present invention is to provide a microwave therapeutic device DC high-voltage isolator, which is designed to be small in size, light in weight and easy to process, and can realize BF type design to isolate DC and high voltage, prevent electric shock when the therapeutic probe contacts the human body, and at the same time effectively output microwave energy to achieve effective therapeutic effect.

[0004] To achieve the above object, the present invention provides a microwave therapeutic apparatus DC high voltage isolator, comprising a first isolation resonant cavity, a second isolation resonant cavity, a first antenna socket, a second antenna socket, and an insulating isolation ring;

[0005] The first and second isolated resonant cavities are coaxially symmetrical open-coupled-hole cylindrical microwave cavities, and the cylindrical cavities are made of metal aluminum with a radius of R and a length of L;

[0006] Furthermore, the resonance frequency expression of the cylindrical resonant cavity is:

[0007]

[0008] Where: 2R and L are the diameter and length of the resonant cavity respectively; ε and μ are the dielectric constant and magnetic permeability of the medium respectively;

[0009] Furthermore, a coupling hole is provided at the connection between the first and second isolation resonant cavities and the antenna socket, and a step is provided in the coupling hole. The hole at the upper part of the step is larger and is used to fix the antenna socket, and the hole at the lower part of the step is smaller and is used to pass the coupling column on the antenna socket, which can reduce the influence of the coupling hole on the coupling;

[0010] Furthermore, the ideal coupling equation between the coupling hole and the resonant cavity is:

[0011]

[0012] Furthermore, the coupling hole is located at the center of the bottom of the cylinder, the polarization direction of the incident electric field is parallel to the coupling hole and the inner side of the cavity, and the field intensity coupled into the cavity is the largest;

[0013] Furthermore, the isolation resonant cavity and the coupling hole are made of metal, the tangential electric field component on the surface of the metal conductor is zero, and for an open space without cavity wall constraints, the real boundary condition is that all components of the electromagnetic field at infinity are zero.

[0014] The first and second antenna sockets are N-type four-hole flange female sockets, the diameter of the conductor coupling column in the antenna socket is >3mm, and the length of the conductor coupling column placed in the resonant cavity is <20mm;

[0015] Furthermore, the conductor coupling column in the antenna socket is provided with a coupling ring at the end of the cavity, and the radius of the coupling ring is greater than 6mm;

[0016] Furthermore, the coupling ring on the first and second antenna sockets is placed at the strongest magnetic field in the resonant cavity working mode, and the ring surface is perpendicular to the magnetic field lines. The coupling ring becomes a magnetic dipole under the action of the magnetic field, and the resonant cavity is coupled to the coaxial line through the action of its magnetic moment. The coupling ring is placed horizontally and perpendicular to the magnetic field lines on the outside of the insulating isolation ring in the middle of the resonant cavity, which is the strongest magnetic field in the resonant cavity working mode. According to the principle of symmetry, the outer side of the middle of the insulating isolation ring of the resonant cavity is also the strongest point of the magnetic field distribution of the coupling ring.

[0017] The insulating isolation ring is made of cylindrical nylon, the thickness of the middle insulating ring is less than 2mm, and the incident electric field obtains a voltage zero point at the insulating isolation ring;

[0018] Furthermore, inner edges of the left and right ends of the insulating isolation ring are provided with internal threads for matching with outer edges of the first and second resonant cavities.

[0019] The technical principle of the present invention is as follows: an insulating ring with a certain strength is used to separate the first and second resonant cavities, so that direct current cannot flow between them, thereby isolating dangerous high voltages; two circular coupling rings of the same area and axial symmetry are used to form a large circular capacitor to achieve high-frequency conduction.

[0020] Compared with the prior art, the microwave therapeutic apparatus DC high voltage isolator provided by the present invention has the following beneficial effects:

[0021] 1. The use of a cylindrical electrically coupled coaxial resonant cavity can effectively reduce the volume of the system. The signal can be directly input into the energy processing module without mode conversion. The resonant frequency range can be freely adjusted up to 9.6 GHz, and efficient microwave power transmission can be performed.

[0022] 2. The nested design of the insulating isolation ring can withstand a creepage distance of up to 5000V, solving the problem of insufficient withstand voltage of general isolators. At the same time, the input cavity end is insulated from the output cavity end, ensuring that the output application part will not be energized and achieve safe isolation.

[0023] 3. The antenna socket of the present invention has symmetrical design at both ends, and both ends can be used as input and output ends. At the same time, the antenna socket is connected to a microwave cable, and the length of the microwave cable can be freely configured, and the placement of the equipment structure is also relatively free and unconstrained.

[0024] 4. The present invention can isolate the direct current between the input and output terminals, thereby protecting the output terminal from the risk of electric shock, has a simple design structure, and has high manufacturing and installation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] See attached Figure 1 As shown, a microwave therapeutic apparatus DC high voltage isolator comprises a first isolation resonant cavity 2, a second isolation resonant cavity 6, a first antenna socket 1, a second antenna socket 5, and an insulating isolation ring 3.

[0028] The first and second isolation resonant cavities 2, 6 are coaxially symmetrical open-coupled cylindrical microwave cavities, and the cylindrical cavities are made of metal aluminum with a radius of R 10 and a length of L 9.

[0029] A coupling hole 11 is provided at the connection between the first and second isolation resonant cavities and the antenna socket, and a step 8 is provided in the coupling hole. The hole at the upper part of the step 8 is larger and is used to fix the antenna socket 1. The hole at the lower part of the step is smaller and is used to pass the coupling column 4 on the antenna socket. At the same time, the influence of the coupling hole on the coupling can be reduced.

[0030] The coupling hole 11 is located at the center of the bottom of the cylinder, the polarization direction of the incident electric field is parallel to the coupling hole and the inner side of the cavity, and the field intensity coupled into the cavity is the largest.

[0031] The isolation resonant cavity and the coupling hole are made of metal, and the tangential electric field component on the surface of the metal conductor is zero. For an open space without cavity wall constraints, the real boundary condition is that all components of the electromagnetic field at infinity are zero;

[0032] The first and second antenna sockets 1, 5 are N-type four-hole flange female sockets. The diameter of the conductor coupling column 4 in the antenna sockets 1, 5 is >3mm, and the length of the conductor coupling column placed in the resonant cavity is <20mm.

[0033] The conductor coupling column 4 in the antenna socket 1, 5 is provided with a coupling ring 7 at the end of the cavity, and the radius of the coupling ring is greater than 6mm.

[0034] The coupling ring 7 on the first and second antenna sockets is placed at the strongest magnetic field in the resonant cavity working mode, and the ring surface is perpendicular to the magnetic field lines. The coupling ring becomes a magnetic dipole under the action of the magnetic field, and the resonant cavity is coupled to the coaxial line through the action of its magnetic moment. The coupling ring 7 is placed horizontally and perpendicular to the magnetic field lines on the outside of the insulating isolation ring 3 in the middle of the resonant cavity, which is the strongest magnetic field in the resonant cavity working mode. According to the principle of symmetry, the outer side of the middle of the insulating isolation ring 3 of the resonant cavity is also the strongest point of the coupling ring magnetic field distribution.

[0035] The insulating isolation ring 3 is made of cylindrical nylon, the thickness of the middle insulating ring is less than 2mm, and the incident electric field obtains a voltage zero point at the insulating isolation ring;

[0036] The inner edges of the left and right ends of the insulating isolation ring 3 are provided with internal threads for matching with the outer edges of the first and second resonant cavities 2 and 6.

[0037] When the present invention is used, the DC high-voltage isolator is installed between the microwave source output end and the application part of the microwave therapeutic device in this embodiment. The insulating isolation ring 3 separates the first and second resonant cavities 2 and 6, so that no DC current can flow between the two, thereby isolating the high dangerous voltage. Two circular coupling rings 7 of the same area and axial symmetry are respectively placed on both sides of the insulating isolation ring 3 to form a large circular capacitor to play a role in high-frequency conduction.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A microwave therapy device DC high voltage isolator, Features: It includes a first isolation resonant cavity, a second isolation resonant cavity, a first antenna socket, a second antenna socket, and an insulating isolation ring; the first antenna socket and the second antenna socket also include a coupling column and a coupling ring; The first isolation resonant cavity and the second isolation resonant cavity are coaxially symmetrical and are cylindrical microwave cavities with coupling holes, and the first isolation resonant cavity and the second isolation resonant cavity are made of metal aluminum; A coupling hole is provided at the connection between the first isolation resonant cavity and the second isolation resonant cavity and the first antenna socket and the second antenna socket, and a step is provided in the coupling hole, the hole at the upper part of the step is larger and is used to fix the antenna socket, and the hole at the lower part of the step is smaller and is used to pass the coupling column on the antenna socket, and the influence of the coupling hole on the coupling signal can be reduced; The coupling hole is located at the center of the bottom of the cylinder, the polarization direction of the incident electric field is parallel to the coupling hole and the inner side of the resonant cavity, and the field strength of the signal coupled into the cavity is the largest; The insulating isolation ring is arranged between the first isolation resonant cavity and the second isolation resonant cavity to separate the first and second isolation resonant cavities, one end of the coupling column is inserted into the lower hole of the step hole, the other end of the coupling column extends toward the insulating isolation ring, and the coupling ring is arranged at one end of the coupling column close to the insulating isolation ring; The coupling ring is placed at the strongest magnetic field of the resonant cavity working mode, and the ring surface is perpendicular to the magnetic lines of force. The coupling ring becomes a magnetic dipole under the action of the magnetic field, and the resonant cavity is coupled to the coaxial line signal of the coupling column through the action of its magnetic moment.

2. The isolator according to claim 1, Features: The insulating isolation ring is made of cylindrical nylon, the thickness of the middle insulating ring is less than 2 mm, and the incident electric field obtains a voltage zero point at the insulating isolation ring; The inner edges of the left and right ends of the insulating isolation ring are provided with internal threads for matching with the external threads provided on the first isolation resonant cavity and the second isolation resonant cavity.

3. The isolator according to claim 1, Features: The first antenna socket and the second antenna socket are N-type four-hole flange female sockets, the coupling column has a diameter of >3mm and a length placed in the resonant cavity of <20mm; The coupling column is provided with a coupling ring at the end of the cavity, and the coupling ring radius is greater than 6mm.

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