SU921581A1 - Electric stimulator - Google Patents

Description

(54) ELECTROSTIMULATOR

one

The invention relates to medical technology, namely, devices for electroanalgesia, and can be used to relieve postoperative pain, as well as neurological pain.

An electrostimulator is known, which contains a master pulse generator with a filling generator, an output stage, a current meter flowing through the patient, electrodes, and a power source 1.

However, in the course of operation of a known electro-stimulator, a manual adjustment of the frequency of the filling generator is performed in order to ensure minimal pain under the electrode at the required stimulation current. As a result, under conditions of a constant change in the impedance of the skin, the likelihood of underestimation or overestimation is not excluded; the amplitude of its stimulating current leads to a decrease in the effectiveness of the therapeutic effect or to pain.

The purpose of the invention is to reduce pain, by automatically adjusting the frequency of stimulation.

The goal is achieved by the fact that. electrostimulator containing associated

between them, the filling generator, setting the pulse generator; the output stage, current meter and electrodes, as well as the power source, a distinctive feature is that the electromotor is additionally equipped with a series-connected phase meter, maximum separation circuit, sawtooth generator and control pulse generator, the phase meter connected to the output stage and meter current and generator 10 of the voltage of the generator with a filling generator.

FIG. 1 shows a structural diagram of an electrostimulator; in fig. 2 - timing diagrams explaining the operation of the electric stimulator.

Claims (1)

The electrostimulator contains interconnected filling generator 1, driving pulse generator 2, output stage 3, current meter 4, electrodes 5, power supply 6. In addition, the electric imotor is equipped with a series-connected phase meter 7, a maximum separation circuit 8, a sawtooth voltage generator 9, and a control pulse generator 10. Moreover, the phase meter 7 is connected to the output stage 3 and the current meter 4, and the sawtooth generator 9 is connected to the filling generator 1. The electrostimulator works as follows. in a way. The generator 10 equalizing pulses produces short voltage pulses Ui, which start the generator 9 of the saw-tooth voltage. The voltage J from the output of the latter causes a smooth change in the frequency of the generator 1 filling. Pulse generator 2 produces pulses of ultrasonic voltage with a rectangular envelope filled with generator frequency 1, which, after amplification in the output stage 3, are applied to electrodes 5 through current meter 4 and applied to electrodes 5. Phase meter 7 measures the phase shift between voltage and current stimulation during the action of the stimulating pulse and the formation of a voltage U4 proportional to this phase shift. At the moment when the voltage U4. passes through a maximum, the maximum allocation circuit 8 will generate a short voltage pulse Ug. This signal acts on the generator 9, thereby stopping the change in voltage at its output and storing the voltage corresponding to the instant of the occurrence of the voltage pulse Us. The process of changing the frequency of the filling generator 1 is stopped because the maximum phase shift between the stimulating current and voltage corresponds to the minimum active power dissipated under the electrodes, then since the appearance of the voltage pulse Us, the filling frequency of the generator 1 as well as the output pulses is equal to pain sensation under the electrodes. The search for the frequency of the filling generator will be performed at the beginning of each cycle of operation, the duration of which is determined by the generator of control pulses. As the impedance changes and the electrode, the phase ratio between the stimulating current and voltage will change and a new filling frequency will be selected corresponding to the minimum active loss, and therefore the minimum pain, under the electrodes. Thus, the frequency of the filling generator, and hence the output stimulating pulses, is equal to the value corresponding to the minimum pain sensation under the electrodes and changes with the stimulation conditions to maintain this minimum. In the proposed electrostimulator, it is possible to set the frequency of the filling generator corresponding to the minimum pain sensation under the electrodes at the required stimulation current. This is due to the fact that the painful feeling under the electrode is related to the ratio of the active and reactive components of the power released under the electrodes on the physiological tissue. In turn, the ratio of the active and reactive components of the power depends on the frequency of filling the stimulating pulses and can be determined by measuring the phase ratio between the output stimulating current and the voltage m. The design of the device provides the setting of the generator filling frequency corresponding to the phase ratio for the minimum active component of the power, i.e., the minimum pain sensation under the electrodes when the impedance of the tissue changes over time, as well as the state of contact of the electrodes with the skin. An electric stimulator containing interconnected filling generator, driving pulse generator, output stage, current meter and electrodes, as well as a power source, characterized in that, in order to reduce pain by automatically adjusting the frequency of stimulation, it is additionally equipped connected in series by a phase meter, a maximum separation circuit, a sawtooth-voltage generator, and a control pulse generator, the phase meter being connected to the output stage and measuring A current is connected, and a sawtooth generator is connected to a filling generator. Sources of information taken into account in the examination 1. UK patent number 1477095, cl. A 61 N 1/36, 1977. U, W Ub AND one/ Fig. /