Figure 3

Examples of the reference respiratory and EDR signals computed from two high-quality (q(k) = 100) segments of the Sleep dataset. Only the EDR signals with the best and worst wave morphology approximations, for these examples, are shown. (a) Segment during deep sleep with b(k) = 0.08 Hz and m(k) = 1. Correlation and coherence were highest for \({\widehat{r}}_{k}(n)\), i.e., ∣ρ∣ = 0.88 and \(\bar{{\gamma }_{r}}=0.98\), and worst for \({\widehat{r}}_{a}(n)\), i.e., ∣ρ∣ = 0.60 and \(\bar{{\gamma }_{r}}=0.82\). (b) Segment with an OSA event with b(k) = 0.57 Hz and m(k) = 5. Correlation and coherence were highest for \({\widehat{r}}_{k}(n)\), i.e., ∣ρ∣ = 0.66 and \(\bar{{\gamma }_{r}}=0.79\), and worst for \({\widehat{r}}_{a}(n)\), i.e., ∣ρ∣ = 0.47 and \(\bar{{\gamma }_{r}}=0.45\). The signal \({\widehat{r}}_{k}(n)\) was inverted to facilitate visualization.