Cross power spectral density between two-lead ECG signals at the termination of obstructive sleep apnea with or without arousals

This study examined the changes of cross power spectrum density (CPSD) of ECG signals between two leads induced during OSA events and the events following its termination with/without arousals. Total 250 OSA events were selected in which only 60 events were not accompanied with ASDA arousals. Total 250 clips (5-second window containing a cycle of inspiration and expiration) during OSA and 250 clips at termination of OSA events from each lead were extracted. CPSD analysis was performed between two leads ECG clips for OSA and its termination. CPSDs of the clips at all frequencies (0~128 Hz) were compared for OSA events and its termination with and without arousals. The results show that during OSA and its termination events without arousals, CPSDs at some frequencies are significantly (p< .01) higher than that in the events with arousals. Results could be useful for predicting the occurrence of respiratory event related cortical arousal using ECGs.