Modified and improved sleep monitoring display console
James D. Frost · NASA STI Repository (National Aeronautics and Space Administration) · 1972
An outline is given of a sleep monitoring display console capable of simultaneously displaying: (1) the visible current sleep stage of each subject, (2) a cumulative, numerical display (in hours and minutes) of the total amount of time the subject spends in each stage, and (3) a stepwise, graphic recording of subject's sleep stage versus time.