SU1690790A1 - Device for uhf-therapy - Google Patents

Abstract

The invention relates to medicine, and in particular to a medical technique used for physiotherapy and hyperthermia in a high frequency electromagnetic field. The purpose of the invention is to expand the possibilities of using the device by performing it as a single module, increasing the efficiency of the device, reducing radiation into the surrounding space, increasing the frequency of exposure, simplifying the design and reducing the weight and size of the device. For this, the UHF-therapy device contains a high-voltage oscillator, a unit including its communication device with the emitter and the emitter due to the following. A resonant circuit is included in the input circuit of the generator, a transformer winding tuned to resonance is connected to the output circuit, and capacitive electrodes are connected to the outputs from the secondary winding of the transformer, separately or with an additional frame, and the high-frequency unit is designed as a module. The circuit in the control circuit of the generator can be made in the form of a cable length of an odd number of half-waves, and the transformer in the output circuit can be made of a length of coaxial cable with a braided gap in the middle folded twice, and the ends of the braid at the ends of the cable segment are closed between themselves and connected to the device. 1 hp f-ly, 2 ill. -w yo

Description

The invention relates to medicine, in particular to a medical technique used for physiotherapy and hyperthermia in a high frequency electromagnetic field. The invention may be applied in other areas where high frequency heating is used.

The aim of the invention is to expand the possibilities of using the device by performing it as a single module, increasing the efficiency of the device, reducing the radiation into the surrounding space, increasing the frequency stability of the effect, simplifying the design and reducing the weight and size of the device.

Figure 1 shows a simplified diagram of a generating module of a device for UHF therapy; figure 2 - variants of the transformer shown in figure 1.

The device consists of cable line 1, generator generator 2, throttle 3, first filter inductor 4, first filter capacitor 5, frame 6, bias resistor 7, second generator lamp 8, second inductor 9, filter second capacitor 10, cable line 11 and plug 12. Frame 6 can be made in the form of a transformer 13 described by the equivalent circuit 14. Turning on the transformer according to the circuit 13 on

ON W) O VI S O

low impedance is carried out according to scheme 15. Asymmetric electrodes can be connected according to scheme 16, and separated electrodes - according to scheme 17,

Radio tubes 2 and 8 constitute a push-pull generator. Their grids are connected by line S to half-wavelengths (segments 18 and 19), the bias resistor 7 is connected in the middle of line 1 for symmetry. Anode power is applied through choke 3. Coils of inductance 4 and 9, as well as capacitors 5 and 10 form low-pass filters. Frame 6 performs the function of the resonant circuit of the generator and the emitter of the magnetic field. Frame b is connected to the generator through a three-stroke connector 12. Frame b can be pulled out into a two-wire line 13c with output wires. Transformer 13 is described by equivalent circuit 14. Option 15 for switching a transformer to a low-impedance load, version 16 for switching a transformer onto an unbalanced load, option 17 for switching a transformer onto spaced electrodes are different cases of connecting the output wires for different cases of microwave therapy.

The generator on the lamps 2 and 8 is assembled according to the tuned anode scheme - the tuned grid. The resonant circuit in the grid circuit is line 18-19 half-wavelength. For greater stability, the frequency of the length of the line 18-19 may be equal to several half-waves (their odd number).

In the anode circuit the resonant circuit is a capacitor 5, made according to the following scheme: frame 6 from a section of coaxial cable with a braided gap in the middle part, insulated, open central conductor, with a section of two-wire line formed from the ends of the segment, the setting node, made in the form of a jumper located on the section of the two-wire line to which the feeder line can be connected to the braid. The anodes of the lamps 2 and 3 are connected to the ends of the cores of the cable segment from which the capacitor 5 is made, since these are the points with the highest resistance in the equivalent circuit. The capacitor 5, made as described above, is used for inductothermy, and for connecting capacitive electrodes, frame 6 is pulled into line 13. In this variant, line 13 is transformed into a transformer with two insulated windings, and the ends of the core and braid at the point of rupture are equivalent. The peculiarity of such a transformer is TPM. Its input and output are spaced apart, and the position of the outputs of one winding is opposite to the middle of the other, thereby eliminating capacitive coupling between the windings. Equivalent to

Transformer circuit 14 according to circuit 13 shows that transformer 13 is a circuit with separated inductance and capacitance and has its own resonant frequency, since the capacitances and inductors of the circuit are distributed, enclosed in a two-wire line inside the cable and outside it, because the resonant size of the transformer pattern 13 is approximately equal to a quarter of the wavelength. A variation according to the transformer circuit 15 according to the circuit 13 shows an autotransformer connection of capacitive electrodes to an equivalent circuit according to the circuit 14. An option according to the circuit 16 is an autotransformer asymmetrical connection, which is used for asymmetric electrodes, i.e. with the asymmetry of the capacitance of the electrodes on the generator housing, it is advantageous with asymmetric irradiation.

5Variant scheme 17 transformer

Scheme 13 is advantageous when the distance between the electrodes is large and serves to reduce the length of the connecting conductors. In this case, it is assumed that the bent halves of the two-wire line emit less into space than the single wire leading to the capacitive electrode. In the variants according to schemes 13, 15, 16 and 17, the circuits according to the generator scheme 14 can be connected to the anodes of lamps 2 and 8 instead of frame b by means of connector 12.

Structurally, the generator on the lamps 2 and 8, the magnetic field emitter and the connecting line (feeder) are one

0 integer, ie, made in the form of a module. The entire module is mounted on the end of the hinge rod of the UHF apparatus, only the power supply and control unit remains in the stationary casing.

5 A diagram of the type of heating, magnetic or electric, is carried out by interchanging the radiator. In the working scheme of the apparatus, it is indispensable to promptly adjust the output circuit to the resonance with

0 grid - manual or automatic. It can be carried out by one of the known methods, in particular, with the help of a tuning capacitor connected to the end of the core of the cable segment from which

5 made emitter,

For experimental verification of the proposed device, a generator was assembled on two GU-72 lamps. Elements of the circuit - cut-off 18 and 19-cable PK50-2-21.2 x 1.9 m; resistor 7-1.5 kΩ. 10 W: coil 4 and

9 to 0.1 μH; capacitors 5 and 10 at 10 pF (filter separation frequency is 40-50 MHz; choke 3 is cylindrical 1 cm, length 10 cm, single layer, MGTF wire 0.12; frame 6 is made of PK50-9-21 cable, diameter 2, 5 cm, loop length 52 cm, tuned to a frequency of 27.12 MHz. Voltages are anode voltages, the screen grid is supplied from the power supply unit of the UHF-80-3 apparatus. The anode current in the operating mode was 350 mA for both lamps. created a magnetic field with induction of 3 - 4 Gs in the center of the circle, which is approximately 1.5 times higher than when connecting the same frame to the UHF-80-3 generator using feeder Line. Frequency drift was controlled by a digital frequency meter and was 1 h after a 15-minute warm-up of 30 kHz, which corresponds to relative instability 1 .. When adjusting the anode circuit, a pronounced maximum of magnetic induction and maximum of anode current is observed in resonance, which can be used for on-line tuning of the generator (on the mock-up, the tuning was made by a differential; social capacitor of 10 pF capacity). Radio tubes are placed in a metal case, which dissipates heat well, the volume of which does not exceed 1.5 - 2 liters. The connector must be recessed to protect against constant voltage. Insulation of this type of cable is sufficient for operating conditions. Additional insulation is needed at the point of the braided rupture of the length of cable from which the radiator or transformer is made. The control of the capacitor from the control panel can be carried out, for example, with the aid of selsins. To increase the temperature stability of the frequency, the grid line should be brought out of the enclosure containing the lamps.

The device works as follows.

When voltage is applied to the generator input, the frequency stability is set by the resonant circuit 1 included in the input circuit of the generator. This forms a strong inductive coupling between the transformer and the generator, and the capacitive coupling of the transformer according to the generator circuit 13c is reduced, due to the fact that the electric field created by the transformer is limited by the size of its windings.

The output (anode) circuit of the generator is connected with the input (grid) through the capacitance anode - grid. This is a weak linkage, in particular when using a pentode. In addition, the grid circuit 1 is made of a cable with low characteristic impedance and its electrical length varies from input through a capacitive (anode reactance grid. Therefore, we can speak of a better isolation 5 of the frequency defining circuit 1 and the load. In addition, The use of a cable resonator in the input circuit increases the frequency stability, in particular, due to the separation of the frequency-setting and heating elements.

The resonating transformer according to scheme 13, used in the output circuit of the generator instead of the traditional C-circuit, is made of a coaxial cable connected in the above manner, which allows, first, to build a single generator-radiating module, and second, connect the generator to the capacitive electrodes with a lossless line, and also coordinate the generator with the load.

Thus, an increase in the stability of the frequency of exposure is achieved. for the fact that it is given by a weakly loaded input resonator remote from

5 heat sources - lamps and having a steep phase response due to a large length in parts of the wave. The reduction of radiation into the surrounding space is ensured by the absence of communication that dissipates energy. The size of the body is small, which makes it an ineffective parasitic emitter. In addition, the wires connecting the module to the power supply are missing.

5 through the ferrite ring - choke, blocking the path of parasitic RF currents. The efficiency increase of the device is achieved due to the fact that the circuit has a single-loop output, a strong connection with the load, no communication line with the radiator. The generator power is better transmitted to the matched load, energy is not dissipated due to the parasitic radiation of the communication line. Execution of the same construction in the form of a single

5, the module allows the UHF apparatus to be made in the form of a generator-emitting module with an external power supply unit. Such a module has small dimensions, weight, and radiates little to the side of the heating region. For these reasons, the procedure can be carried out on a bed in the ward, and the session time can be longer than in the room conditions, which will increase the effectiveness of the treatment. At the same time simplifying the design of the device

5 is achieved by making contours from cable sections, eliminates such complex components as high-frequency coils and variable capacitors, and mechanical nodes

mounting and shielding, and reducing

the masses and dimensions of the device are due to the fact that there are no coils and capacitors designed for high reactive power, screens, fixing elements of the communication line and the line itself - all this replaces cable sections.

Claims (2)

Claim 1. A device for UHF-therapy, comprising a generator, including an amplifying element and two resonant circuits, as well as a radiator in the form of capacitive electrodes, characterized in that, in order to expand the possibilities of using the device by performing it as a single module, increase the efficiency of the device, reduce radiation into the surrounding space, increase the stability of the generation frequency, simplify the design and reduce the mass and dimensions of the device; its resonant circuits are made of segments oaksialnogo cable, one of which has a length equal to an odd number of half the working length waves and connected to the input of the amplifying element of the generator, and the second segment is folded in half into a two-wire line and connected to the output of the amplifying element by the ends of the central conductor and the device body by the ends of the braid, and this resonant circuit has a braid gap in the middle, its capacitive electrodes are connected to half of its braid. 2. The device according to claim 1. This is due to the fact that the middle of the second segment is curved in an arc, with the convex part facing the ends of the segment with the formation of an additional inductive electrode - the frame. 18 1lm look for Wffffihfl V l to C 1 I TO NJ I R well