CN111293391A - A kind of microwave therapeutic apparatus DC high voltage isolator - Google Patents

Abstract

The invention relates to a circuit breaker, in particular to a DC high voltage circuit breaker for a microwave therapeutic apparatus, and belongs to the technical field of microwave isolators. According to the technical solution provided by the present invention, the DC high voltage isolator of a microwave therapeutic apparatus 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, the radius is R, and the length is L; the first and second antenna sockets are N-type four-hole flange base, the diameter of the inner conductor coupling column of 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, and the thickness of the insulating ring in the middle <2mm, the incident electric field obtains the voltage zero point at the insulating isolation ring; the invention can realize the BF type design, realize the isolation of direct current and high voltage, prevent electric shock when the treatment probe contacts the human body, and at the same time can effectively output microwave energy to achieve effective treatment effect.

Description

A kind of microwave therapeutic apparatus DC high voltage isolator

technical field

The invention relates to the technical field of microwave isolators, in particular to a DC high-voltage isolator of a microwave therapeutic apparatus.

Background technique

The microwave therapeutic apparatus treats diseases mainly by consuming microwave energy to generate heat effect, and with the help of these heat, it can achieve the effect of treating various diseases. Microwaves are emitted from the microwave therapeutic apparatus, and are output to the therapeutic probe through the microwave cable, intervening into the lesions of the patient's local tissue for treatment. According to the anti-shock classification requirements of medical electrical equipment, the application part of the microwave therapy equipment must be BF type equipment, that is, this equipment is suitable for the body surface and body cavity, but it needs to have an insulating contact with the patient. Most of the existing microwave therapy instruments are mainly designed with BF-type isolation through the circuit part. However, because the core microwave output components of the equipment have high power and high voltage, such design methods are complicated, and it is difficult to effectively isolate DC high voltage, which is easy to have. Safety risk of leakage to the applied part.

SUMMARY OF THE INVENTION

The purpose of the embodiments of the present invention is to provide a DC high-voltage circuit breaker for a microwave therapeutic apparatus, which is small in design, light in weight, easy to process, and can realize a BF type design, realize isolation of DC and high voltage, prevent electric shock when the therapeutic probe contacts the human body, and at the same time It can effectively output microwave energy to achieve effective treatment effect.

In order to achieve the above purpose, the present invention provides a DC high voltage isolator for a microwave therapeutic apparatus, comprising 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, and the cylindrical cavity is made of metal aluminum, with a radius of R and a length of L;

Further, the resonant frequency expression of the cylindrical resonant cavity is:

where 2R and L are the diameter and length of the resonant cavity, respectively; ε and μ are the dielectric constant and permeability of the medium, respectively;

Further, a coupling hole is provided at the connection between the first and second isolation resonant cavity and the antenna socket, and a step is arranged in the coupling hole. The upper hole of the step is larger for fixing the antenna socket. In order to pass the coupling column on the antenna socket, the influence of the coupling hole on the coupling can be reduced at the same time;

Further, the ideal coupling equation between the coupling hole and the resonant cavity is:

Further, 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 inside of the cavity, and the field strength value coupled into the cavity is the largest;

Further, the isolated 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 each component of the electromagnetic field at infinity is zero. .

The first and second antenna sockets are N-type four-hole flange 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;

Further, the inner conductor coupling column of the antenna socket is provided with a coupling ring at the end of the cavity, and the radius of the coupling ring is >6mm;

Further, the coupling loop on the first and second antenna sockets is placed at the strongest magnetic field in the resonant cavity working mode, and the loop surface is perpendicular to the magnetic field line, and the coupling loop becomes a magnetic dipole under the action of the magnetic field. The action of its magnetic moment couples the cavity to the coaxial line. The coupling ring is placed horizontally and perpendicular to the magnetic field line outside the insulating isolation ring in the middle of the resonant cavity, that is, where the magnetic field of the working mode of the resonant cavity is the strongest. According to the symmetry principle, the outer middle of the insulating isolation ring of the resonator is also the strongest part of the magnetic field distribution of the coupling ring.

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

Further, inner threads are provided on the inner edges of the left and right ends of the insulating isolation ring for matching with the outer threads provided on the outer edges of the first and second resonant cavities.

The technical principle of the present invention: using an insulating ring with a certain strength in the middle to separate, the first and second resonant cavities cannot pass direct current, and the effect of high dangerous voltage is separated; two circular couplings with the same area and axisymmetrical coupling are used. The ring, forming a large ring-shaped capacitor plays the role of high-frequency conduction.

Compared with the prior art, the DC high-voltage circuit breaker for a microwave therapeutic apparatus provided by the present invention has the following beneficial effects:

1. The use of cylindrical electrically coupled coaxial resonator can effectively reduce the volume of the system, and the signal can be directly input to the energy processing module without mode conversion. Transmission of microwave power.

2. The insulating isolation ring with nesting design can withstand the creepage distance of up to 5000V withstand voltage, which solves the problem of insufficient withstand voltage of the general isolator. At the same time, the input cavity end is insulated from the output cavity end, ensuring the output application part. It will not be electrified, so it can be safely isolated.

3. The two ends of the antenna socket of the present invention are symmetrically designed, and both ends can be used as input and output terminals. At the same time, the antenna socket is connected to the microwave cable. The length of the microwave cable can be freely configured, and the device structure placement is relatively free and unconstrained.

4. The present invention can isolate the direct current between the input and output terminals, so as to protect the output terminals from the risk of electric shock, the design structure is simple, and the manufacturing and installation efficiency is high.

Description of drawings

FIG. 1 is a schematic diagram of the overall structure of the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments.

Referring to FIG. 1 , a DC high voltage isolator of a microwave therapeutic apparatus includes 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 .

The first and second isolation resonant cavities 2 and 6 are coaxially symmetrical open-coupling hole cylindrical microwave cavities, and the cylindrical cavity is made of metal aluminum with a radius of R 10 and a length of L 9.

A coupling hole 11 is provided at the connection between the first and second isolation resonant cavity and the antenna socket, and a step 8 is arranged in the coupling hole. It is used to pass the coupling column 4 on the antenna socket, and at the same time, the influence of the coupling hole on the coupling can be reduced.

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 inside of the cavity, and the field strength value coupled into the cavity is the largest.

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 each component of the electromagnetic field at infinity is zero;

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

The inner conductor coupling column 4 of the antenna sockets 1 and 5 is provided with a coupling ring 7 at the end of the cavity, and the radius of the coupling ring is >6 mm.

The coupling ring 7 on the first and second antenna sockets is placed at the strongest magnetic field in the working mode of the resonant cavity, and the ring surface is perpendicular to the magnetic field line. The coupling ring becomes a magnetic dipole under the action of the magnetic field, and through its magnetic moment The role of the resonator is coupled with the coaxial line. The coupling ring 7 is placed outside the insulating isolation ring 3 in the middle of the resonant cavity horizontally and perpendicular to the magnetic field line, that is, the place where the magnetic field of the working mode of the resonant cavity is the strongest. According to the symmetry principle, it can be known that the middle and outer side of the insulating isolation ring 3 of the resonant cavity is also the strongest part of the magnetic field distribution of the coupling ring.

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

The inner edges of the left and right ends of the insulating isolation ring 3 are provided with inner threads, which are used for matching with the outer threads provided on the upper outer edges of the first and second resonant cavities 2 and 6 .

When using the present invention to work, in this embodiment, the DC high voltage isolator is installed between the output end of the microwave source and the application part of the microwave therapeutic apparatus, the insulating isolation ring 3 separates the first and second resonant cavities 2, 6, and the two There is no direct current between them, and the role of high dangerous voltage is separated; two circular coupling rings 7 with the same area and axisymmetric are placed on both sides of the insulating isolation ring 3 respectively, forming a large circular ring capacitor to conduct high-frequency conduction. the role of communication;

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Various modifications and variations of the present invention are possible for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention. The protection scope of the patent of the present invention is subject to the appended claims.

Claims (3)

1. A direct-current high-voltage breaker of a microwave therapeutic apparatus comprises a first isolation resonant cavity, a second isolation resonant cavity, a first antenna socket, a second antenna socket and an insulation isolation ring;

the first and second isolation resonant cavities are coaxial and symmetrical cylindrical microwave cavities with coupling holes, the cylindrical cavities are made of metal aluminum, the radius is R, and the length is L;

the resonant frequency expression of the cylindrical resonant cavity is as follows:

in the formula: 2R and L are respectively the diameter and the length of the resonant cavity; epsilon and mu are respectively dielectric constant and magnetic permeability of the medium;

a coupling hole is formed at the joint of the first and second isolation resonant cavities and the antenna socket, a step is arranged in the coupling hole, a hole in the upper part of the step is larger and used for fixing the antenna socket, and a hole in the lower part of the step is smaller and used for passing through a coupling column on the antenna socket, so that the influence of the coupling hole on coupling can be reduced;

the ideal coupling equation between the coupling hole and the resonant cavity is as follows:

the coupling hole is positioned at the center of the bottom of the cylinder, the polarization direction of an incident electric field is parallel to the coupling hole and the inner side of the cavity, and the field intensity value coupled into the cavity is the maximum;

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 the constraint of the wall of the cavity, the real boundary condition is that each component of an electromagnetic field at infinity is zero.

2. The breaker of claim 1, wherein 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 <20 mm;

a coupling ring is arranged at the tail end of the cavity of the antenna socket inner conductor coupling column, and the radius of the coupling ring is more than 6 mm;

the coupling ring on the first and second antenna sockets is arranged at the strongest position of a magnetic field in a resonant cavity working mode, the ring surface is vertical to a magnetic line of force, the coupling ring becomes a magnetic dipole under the action of the magnetic field, and the resonant cavity is coupled with the coaxial line under the action of the magnetic moment of the coupling ring; the coupling ring is horizontally arranged outside the middle insulating isolation ring of the resonant cavity and is vertical to the magnetic force line, namely the strongest position of the magnetic field of the working mode of the resonant cavity; according to the symmetry principle, the outer side of the middle of the resonant cavity insulating isolation ring is also the strongest part of the magnetic field distribution of the coupling ring.

3. The breaker of claim 1, wherein the insulating isolation ring is made of cylindrical nylon, the thickness of the insulating ring in the middle is less than 2mm, and an incident electric field obtains a voltage zero point at the insulating isolation ring;

and internal threads are arranged on the inner side edges of the left end and the right end of the insulating isolating ring and are used for being matched with the external threads arranged on the first resonant cavity.

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