Figure 2
From: A Comparative Study of ECG-derived Respiration in Ambulatory Monitoring using the Single-lead ECG
Examples of respiratory segments with different spectral characteristics during deep sleep (a), apnea (b), and driving (c). The PSD of each segment is displayed at the bottom, and the shaded area indicate the bandwidth b(k). The number of modes m(k) is also indicated. a.u. stands for arbitrary units. The distribution of b(k) (top) and m(k) (bottom) for all datasets are indicated in (d).
