A new approach used to extract fluctuations in vagal activity-Wigner distribution of heart rate variability

The Wigner Distribution of Heart Date Variability (HRV), is introduced to extract the fluctuations of rats´ vagal activity. Traditional spectral analysis, using FFT or auto-regressive models, of beat-to-beat heart rate variability, is not well suited for tracking transient changes of autonomic function over time. In this study, the Wigner distribution of the HRV was used to derive instantaneous vagal activity by extracting the high frequency component (0.8 Hz to 23 Hz) in the HRV signal for each instant of time (512 msec). To test the effectiveness of the algorithm the derived vagal signal was compared with the real vagal signal recorded from the right cut cervical vagus. The results showed significant agreement