Analysis of Heart Rate Variability and Breath To Breath Interval in frequency domain

Respiratory is known to be a confounding factor of Heart Rate Variability (HRV) analysis. This article introduces a Breath-to-Breath Interval (BBI) spectral computation to investigate the insight between respiration and the HRV. Six males and five female volunteers (age 20-25 years) underwent the Electrocardiogram (ECG) and respiratory chest movement recordings for 5 minutes while sitting in resting condition. Auto Regressive Moving Average (ARMA) model was employed to the R-wave to R-wave interval (RRI) and BBI signals for the spectral analysis. The results from all participants demonstrate that the peak amplitude in high frequency (0.15-0.40 Hz) band are higher than the ones in low frequency (0.04-0.15 Hz) band in both RRI and BBI frequency plots. It suggests that respiratory plays a major role in HRV oscillation. Our further study is to develop a mathematical model to explain this finding.