Polysomnographic studies are the main method for sleep disturbances diagnostics (insomnia, hypersomnia, parasomnia, narcolepsy), sleep respiratory distress (sleep apnoea syndrome, alveolar hypoventilation, snore) and concomitant cardiovascular diseases (heart rate disturbance, coronary disease), and also neurological and psychosomatic disturbances (epilepsy, restless legs syndrome, bruxism, etc.) Studies can be carried out both in autonomous (at the patient's whereabouts, with record to the flash-card, like Holter type) and in telemetric (Bluetooth) mode.