Real-time Continuous Estimation of Respiratory Frequency during Sleep based on Heart Rate Time Series

It is reported that frequency component (RSA)of approximately 0.25Hz of heart rate time series is corresponding to the respiratory frequency. In this paper, we proposed the continuous estimation method of respiratory fequency during sleep using the number of extreme points of heart rate time series in real time. Procedure for calculation of the method is very simple. Frequency of RSAwas calculated using the proposed method from the heart rate time series during supine rest and during sleep.lt is considered that the proposed method can be applied to respiratory monitoring system during sleep.