New statistical method for detection and quantification of respiratory sinus arrhythmia

A statistical method with the advantages of (1) enabling graphical representation of within-respiratory cycle heart rate variations, (2) detecting the presence of respiratory sinus arrhythmia (RSA) in a moving window, and (3) providing breath-by-breath RSA amplitude and phase obtained from the fitting of a sinusoid to the instantaneous relative heart rate is presented.