Study of the relationship between Pulse Photopletismography amplitude decrease events and sleep apneas in children

In this work, a method to analyse the effects of an apnea on the pulse photoplethysmography signal (PPG) is proposed. Therefore, an apnea detector based on respiratory signals has been developed and a decreases in amplitude of PPG (DAP) detector developed in a previous study was used. The apnea detector was tested using real signals. S and +PV of the detector were 95.3% and 94.4%, respectively. For each of the apneic events, we analyzed the presence of DAP in a window previous to the apnea event and another during/following the apnea. An increase of about 15% in DAP events in the window during/following the apnea with respect to the previous to apnea window is produced. These results shows an association between apneic events and DAP events, which indicates that DAP events provide useful information in sleep research and PPG signals might be useful in the diagnosis of OSAS.