Neuron-Spectrum-PSG system complements digital EEG systems of Neuron-Spectrum series by transforming EEG systems to complete PSG system. Long-term synchronous recording of EEG, polygraphic channels, video and audio information, sleep stage analysis and analysis of sleep-disordered breathing arrange a combination required for high-quality PSG study. The convenience and the simplicity for use make Neuron-Spectrum-PSG an indispensable helper during PSG recording and scoring. This system provides new possibilities for diagnostics, prevention and treatment of such widespread diseases as essential hypertension, obesity, arrhythmias, infarctions, strokes.