Two-group classification of patients with obstructive sleep apnea based on analysis of brain recurrence.

•The severity of obstructive sleep apnea (OSA) was directly reflected in the sleep EEG.•Binary classification of patients with OSA (mild or moderate) was achieved by analyzing the EEG from one derivation.•Analysis of brain recurrence is an effective algorithmic technique for extracting useful diagnostic information regarding OSA from the EEG.