Table 1. Class, AHI value and sleep durations of selected EEG signals.

A high AHI value means that the severity of sleep apnea is also high. A value greater than five indicates the severity of sleep apnea syndrome. These EEG signals of approximately 6–7 h were segmented into 30 s segments, which is the length frequently used in the literature, and grouped into four classes: mild, moderate, severe.

Class	AHI value	Sleep duration (h)
Healthy	2	6.8
Mild	5	6.4
Moderate	25	7.2
Severe	91	5.9