Electrotherapy unit Etius is intended for carrying out treatment procedures using: bipolar (bidirectional) and unipolar (unidirectional) low frequency currents bipolar (bidirectional) medium frequency currents and unipolar (unidirectional) medium frequency currents modulated by low frequency waveforms The Etius unit is equipped with two completely independent treatment electrotherapy channels with the possibility of correlation in order to perform treatment using four electrodes. The Etius unit may be operated in one of two modes: when the output current is stabilized and when the output voltage is stabilized. The latter one is suitable for performing treatment without a dedicated area and for a combined therapy.