STATISTICAL PROPERTIES OF THE INTERBEAT INTERVAL CASCADE IN HUMAN HEARTS

FATEMEH GHASEMI, J. PEINKE, M. REZA RAHIMI TABAR, MUHAMMAD SAHIMI
2006 International Journal of Modern Physics C  
Statistical properties of interbeat intervals cascade are evaluated by considering the joint probability distribution P(Δ x_2,τ_2;Δ x_1,τ_1) for two interbeat increments Δ x_1 and Δ x_2 of different time scales τ_1 and τ_2. We present evidence that the conditional probability distribution P(Δ x_2,τ_2|Δ x_1,τ_1) may obey a Chapman-Kolmogorov equation. The corresponding Kramers-Moyal (KM) coefficients are evaluated. It is shown that while the first and second KM coefficients, i.e., the drift and
more » ... iffusion coefficients, take on well-defined and significant values, the higher-order coefficients in the KM expansion are very small. As a result, the joint probability distributions of the increments in the interbeat intervals obey a Fokker-Planck equation. The method provides a novel technique for distinguishing the two classes of subjects in terms of the drift and diffusion coefficients, which behave differently for two classes of the subjects, namely, healthy subjects and those with congestive heart failure.
doi:10.1142/s0129183106008704 fatcat:zeyl6nkrw5fkddkg5frjnk3woe