Figure 1
From: A Case of Obstructive Sleep Apnea and Assessments of Fitness for Work

An overnight summary view of polysomnography of the case shows respiratory events, arousals, desaturation events, arterial oxygen saturation, and sleep stages. The sleep study revealed an AHI score of 84.3 and lowest oxygen saturation of 70%, which is consistent with a diagnosis of severe obstructive sleep apnea with desaturation. SaO2 = arterial oxygen saturation, AHI = apnea hypopnea index, Mvt = movement, W = waking state R = rapid eye movement sleep, and N1, N2, and N3 = non-REM sleep stages.