Stochastic and Chaotic Assessment of Human Involuntary Movements

Abstract

According to theory of chaos and self-organization calculation of chaotic dynamics of postural tremor parameters is presented. We have shown that stochastic approach, calculation of distribution function for reiterations of measurements, tremorograms in one subject exhibits chaotic dynamics of these functions f(x). Otherwise 15 measurements by 5 seconds tremerograms show impossibility of coincidence f(x) at pairwise comparison (105 pairs) of tremerograms. Functions f(x) can coincide (for pairs of tremorograms) less than 2-5% from the general number without effect on a person. However, physical load increases the coincidence to 10-15%. Simultaneously, all the amplitude-frequency characteristics do not coincide, Lyapunov constants cannot be calculated, but autocorrelation functions do not reach zero. All the stochastic parameters exhibit constant changes. Calculation of quasi-attractors can provide real distinction between biomechanical system before static load and after. Sizes of quasi-attractor (square and volume) can show distinctions in physiological body states for continuous motions x(t), i.e. for dx/dt≠ 0.