Interference and phase locking patterns between low and high frequency rhythms of cardiovascular variability signals in normal subjects

Analysis of interference and phase locking phenomena between respiration and short-term Heart Rate and Blood Pressure variability signals have been performed by using nonlinear signal processing techniques, such as Poincare Maps, Recurrence Maps, Time-Space Separation Plots and Bispectrum Estimation. Data obtained from normal subjects confirm the hypothesis of non-linear interaction of Low and High frequency rhythms with respiration.