This is a cross-sectional study collecting data from patients from the Sleep Institute of Itaperuna, Rio de Janeiro, Brazil. Polysomnography (PSG) monitoring and diagnosis was in accordance with American Society of Sleep Medicine (ASSM) standards. Standard baseline polysomnography is performed using a computerised system. The following extracted signals are measured: 2 electroencephalogram channels (O1-A2, O2-A1, C3-A2, C4-A1), 2 electrooculogram channels, electromyography (EMG, bilateral anterior tibialis), pulse oximetry (arterial oxygen saturation), nasal-oral airflow (thermistors), and electrocardiogram (ECG derivation DII). The polysomnograms are scored according to the criteria of Rechtschaffen and Kales.