Abstract: A method for determining the sleep state of a patient includes monitoring heart rate variability of the patient and determining sleep state based on the heart rate variability. The method also may include monitoring the frequency of eyelid movements and making the sleep state determination based also on the frequency of eyelid movements. A method for determining respiratory pattern includes monitoring heart rate variability by receiving heart beat signals and determining respiratory pattern from the strength of the signals. A home-based, wearable, self-contained system determines sleep-state and respiratory pattern, and assesses cardiorespiratory risk, of a patient based on the frequency of eyelid movements, the frequency of head movements, and heart rate variability of the patient.

Abstract: Electronic filters are applied to analog signals representative of eye movement and head movement, obtained from detectors attached to a simple headgear, to provide satisfactory information for automatically reporting an individual's sleep state. The filters determine whether there has been substantial eye and head movement in a given period. Each filter then generates binary output signals representing movement (or the absence of it). Noise filters and a comparison filter are then applied to the binary output signals to predict sleep state; REM sleep; NREM sleep; or wakefulness.