Multifractal-Multiscale Analysis of Cardiovascular Signals: A DFA-Based Characterization of Blood Pressure and Heart-Rate Complexity by Gender

Figure 3

Example of multifractal and multiscale coefficients, , for IBI, SBP, and DBP. Data recorded in a male, normotensive volunteer. In this example, of IBI decreases steeply with τ at scales shorter than 16 s, from values typical of fractional Brownian motions to values typical of fractional Gaussian noises . Even if α is lower than 1 at larger scales, the surface is not flat and a relative maximum appears at  s, more pronounced for positive rather than for negative q values. SBP differs remarkably from IBI: α tends to be greater at scales > 64 s, and pronounced local maxima appear when . DBP differs from IBI and SBP: increases at  s for any q, reaching values greater than 1; and no local maxima appear at  s.