Automatic quantification of light sleep shows differences between apnea patients and healthy subjects.

A fully automatic method to quantify sleep depth during the night was developed in the present work. The method was tested using 20 all-night recordings from 10 healthy control subjects and 10 sleep apnea patients. The results showed statistically significant differences in sleep depth between control subjects and sleep apnea patients. The overall sleep was lighter in apnea patients than in healthy control subjects, most likely indicating a disturbed sleep caused by apneas. The automatic parameters presented provide a method to quantify the light sleep and could in the future possibly be used in clinical sleep studies and follow-up of treatment.