Generalized distribution and Q statistics evidences in heart rate variability

Tsallis [Physica A, 340 (2004) 1] identified a set of numbers ldquoq-tripletrdquo = (q-stat, q-sen, q-rel) suitable for a complex system with scale-invariance feature. When q = 1, the generalized q-Gaussian assumes classical Gaussian distribution form. Deviation of the q from unit is a measure of the departure from thermodynamics equilibrium. This work presents q-stat, one of the q-triplet numbers, for heart rate variability (HRV) system. The q-stat states for the probability distribution of a system in phase space. A collection of normal subjects HRV data was fitted to generalized q-Gaussian distribution to find out which q value correspond to the dynamical system. The heart rate signals were obtained from the PhysioBank Normal Sinus Rhythm RR Interval Database. The results have shown a tending number for generalized parametric value for q systematically different from unit when distributions were fitted by q-Gaussian. Findings from the results suggest that generalized q-statistics is more suitable for HRV system investigations.