Diagnostic and therapeutic stimulating appts. for paralysed muscles - has pulse generating circuit with changeover switch, generating periodical pulse trains of opposite sign with DC zero compensation

摘要

The appts. is also used for generating controlled movements of disabled musles. It has several electrodes, applicable to the patient's skin, possibly over an intermediate layer of suitable substance. The electrodes are supplied by a circuit generating suitable pulses of stimulating current. The circuit has a change-over switch (5) of such an arrangement that, after a preset train of unipolar stimulating pulses and a preset interval a train of identically long stimulating pulses can be generated, however, with opposite sign. The arrangement is such that the d.c. mean value of the stimulating pulses, supplied to the patient, is compensated to zero. Pref. after each stimulating pulse of a given polarity, a pulse of opposite polarity follows after adjustable interval with current-time compensation. These ambipolar stimulating pulses may be modulated with a medium frequency carried signal by multiplication in such a manner that alternating pulse blocks, corresponding to the ambipolar wave form are generated.