1 Introduction Obstructive sleep apnea (OSA) is characterised by repetitive respiratory events that are associated with hypoxia, hypercarbia and sleep fragmentation. Clinically, the severity of OSA is based on the number of apneas and hypopneas occurring per hour of sleep (AHI), and on conventional measures of oxygen saturation, such as the oxygen saturation nadir and the counts of dips in SpO2, known as oxygen desaturation indices (ODI) (Osorio et al. 2022; Martinez-Garcia et al. 2023).