Adaptive cancellation of respiratory sinus arrhythmia

The influence of respiration is considered as added interference in the heart rate variation (HRV). The temperature of the nasal air flow is recorded and used as a respiratory signal. Given the signal, the respiratory influence is separated from the simultaneously recorded HRV by means of an adaptive noise canceling algorithm. This method has been used to analyze the HRV of healthy volunteers at rest and after autonomic blockade. Experiments indicate that broad or vaguely defined spectral components caused by irregular breathing also can be extracted using this algorithm. It is concluded that this method, in combination with spectral analysis, might improve the quantification of respiratory sinus arrhythmia