Fig. 6From: Automatic sleep stage classification based on subcutaneous EEG in patients with epilepsyManually scored hypnograms based on scalp EEG. The five tick marks on the y-axis represent (from top to bottom) wake, REM sleep, N1, N2 and N3. REM sleep is marked with a red, bold line. Three nights were recorded for each of patients A, C and D, and two nights were recorded for patient BBack to article page