GB1479734A - Electromedical apparatus - Google Patents

Abstract

1479734 Electro-medical apparatus C W MORLE (W L S Kloosman) 15 July 1974 [16 July 1973] 33841/73 Heading A5R An apparatus for electro-medical treatment of a patient, comprises a generator of both voltage and current pulses, the voltage pulses being variable as to frequency, pulse width, amplitude, duration of treatment and polarity, and the current pulses being variable as to frequency, pulse width and duration of treatment, electrodes connected to the generator for applying voltage pulses to the patient, and a coil connectable to the generator for applying a magnetic field corresponding to the current pulses. The frequency may be 20-2000 pulses per second, the amplitude may be 12-20 volts for the voltage pulses and 0-500 microamps for the current pulses, the pulse width may be 0.2-0.9 of the pulse period, and the pulses may be either positive or negative or alternately positive and negative. A unijunction transistor Q1 produces oscillations at a frequency determined by a resistor R1, variable by a control (17), Fig. 1 (not shown), and a capacitor 31 to which may be connected a capacitor 32 by a switch S1A (16) giving factors Xl or X10. The oscillator output is applied via an emitterfollower Q2 to transistors Q3, Q4 from which two trains of oppositely phased pulses are passed to transistors Q9, Q13 and Q10, Q14 respectively. A pair of transistors Q7, Q8 of which one is off when the other is on acts as a gate, to pass one train of pulses or the other. Transistors Q11 and Q12 are coupled respectively to Q9 and Q10, the transistors Q11-Q14 forming a bridge circuit in which either the pair Q11, Q13 or the pair Q12, Q14 is operative according to whether Q7 or Q8 is off. The voltage pulse output is taken from a set of ten potentiometers 40 (only one shown), with controls (15a - 15j), feeding ten sockets (14a - 14j). A multivibrator comprising transistors Q5, Q6 drives Q7 and Q8 so that the polarity of the output alternates when a switch 37 (19) is centralised. Other positions of switch 37 provide for positive or negative pulses respectively. A second output from transistor Q4 is applied to Q15 which feeds pulsed current to terminals 42, corresponding to a socket (12) for the magnetic field coil. The equipment includes a control (23) for timing the operation of the apparatus which is powered by a rechargeable battery. The voltage electrodes may be of nickel, or of aluminium or stainless steel foil.