The present invention relates to a method of analyzing a subject for excessive daytime sleepiness, and more particularly to a quick (short duration), quantitative method of analyzing a subject for sleep apnea. The present invention additionally relates a device for use in detecting excessive daytime sleepiness (EDS) and another device for detecting sleep apnea. One embodiment of the present invention includes a method of screening for sleep apnea comprising of measuring EEG signals from a subject to determine sleep onset time(s) over a measurement period, as well as measuring and analyzing respirations of the subject to determine variability of the subject's respiration about the sleep onset time(s). A determination about whether the subject has sleep apnea will be based in part on the variability of the subject's respirations about the sleep onset time(s).