Improvement of the night sleep quality by electrocutaneous subthreshold stimulation synchronized with the slow wave sleep

Changes in sleep characteristics were studied under the non-wake-up stimulation with current pulses of less than 1 μA on average, applied to the palmar surface skin receptors during Δ-sleep. A significant increase in duration of the first and second cycles of deep sleep has been found, as well as a shorter latent period before the Δ-sleep onset and a longer time of the rapid sleep (REM phase). The sleep structure improvement was accompanied by the reduced reactive anxiety and depression and an increase in subjective physical efficiency.