Figure 9.

Extraction of PPGi and respiratory signals from segmented skin area. (a) Video frames with segmented skin area provided by our proposed framework. (b) Timeline of patient activities over a 60 min segment for a typical recording session, manually annotated over a minute-by-minute basis. (c) Timeline of predicted time periods for infant absence and clinical intervention provided by the proposed algorithms. (d) 60 min time series of the PPGi signal extracted from the mean pixel intensity of the entire segmented skin region in the green channel. (e) 60 min time series of the respiratory signal extracted from the area of the entire segmented skin region. (f) Comparison of non-contact PPGi, contact ECG, and contact PPG signals for the area highlighted in (d). Each signal contains 78 peaks corresponding to a heart rate of 156 beats min⁻¹. (g) Comparison of non-contact respiratory and contact impedance pneumographic (IP) signals for the area highlighted in (e). Each signal contains 35 peaks corresponding to a respiratory rate of 70 beats min⁻¹.