Telephone transmission of all-night polysomnographic data from subjects' homes.

All-night sleep recordings, essential for obtaining measurements of sleep and for diagnosing various sleep disorders, have been restricted primarily to laboratory settings. Described here is a system to complete all-night-sleep recordings in subjects' homes. Eight electroencephalogram channels can be fed into a portable transmitter (which contains a preamplifier and frequency modulator), and transmitted over telephone lines to a receiving polygraph at a remote laboratory. No polygraph is required at the transmission site. Evidence of good signal quality is presented. The clinical and research implications of this methodology are discussed.