 Currently, the presence of sleep-apnea is determined by the apnea-hypopnea index AHI, using in-hospital sleep recording. With a growing number of referrals, waiting lists for sleep registration are emerging. Screening for SAS using home-measurement of nasal pressure and SaO2 seems to be a good alternative. The investigators hypothesize that the DLI derived from these signals gives a better reflection of the pathophysiology of the disease than the AHI. As a result, the investigators expect that the DLI improves the distinction between healthy and diseased subjects in comparison to the simple counting of apneas and hypopneas. This is reflected in a higher area under the ROC curve, which describes the sensitivity and specificity of the test. 