Characteristic parameters of multifractal singularity spectrum of synchronous 12-lead ECG signals

After analysing f(α), the multifractal singularity spectrum of the synchronous 12-lead ECG signals (MSSSE), the authors find that the Δα(the range of singularity strength α) of MSSSE is dispersed. In order to quantitatively analyze curves of multifractal spectrum derived from 12-lead ECG signals, we compute both the Δα̅(the mean of Δαs for 12-lead ECG) and the dispersing degree δ_Δα(defined as standard deviation of Δαs for 12-lead ECG signals) as characteristic parameters. With comparison of these characteristic parameters between the people with good health and heart disease, we find that the Δα̅s are close to each other, but the δ_Δαs are different. We also compare these characteristic parameters between the people with good health and brain disease, and find a dissimilar result, i.e. the Δα̅s are different from each other while the δ_Δαs are close. It implies that the characteristic parameters of multifractal spectrum are controlled by both the body´s neurosystem and self-syntonic property of cardiac structures. Furthermore, the Δα̅ is related with neuroautonomic control on the ECG, and the δ_Δα is related with the spatial anisotropic propagation of the ECG signal in the myocardium.