RESUMO
The paper analyzes theoretical models of the adaptive modes of generation and stability of human heart as a nonlinear point source. The analysis encompasses only ECG time-domain dynamics. To solve the general problem of the study of the adaptive changes of the cardiosignal under the action of external periodic force and parametric noise, a new dynamic model is proposed, which incorporates two control physical parameters: power of signal generation and coefficient of diffuse signal scattering. For the entire set of parameters, the examined modeled nonlinear system demonstrated a number of various performance modes ranging from steady-state periodic and quasi-periodic states to chaos. The model showed that variations in cosmic, geophysical, and weather conditions in the frequency range of 0.1-0.9 Hz produce the greatest biotropic influence.
