Abstract :
A simple continuous nonlinear model of the human cardiovascular system (CVS) is investigated while focusing on the simulated achieved blood pressure (BP) signal. The beat-to-beat version of this model, introduced by DeBoer et. al. was a simplified linearized version. We present a modified model, which allows investigating the nonlinear dynamics of the CVS and the effect of variations in several physiological parameters on the correlation dimension, D2. The simulation reveals nonlinear features such as bifurcation, due to variations in the α-sympathetic gain and the respiratory term. In addition, we studied the limitations of calculating D2 in the presence of noise. The D2 values obtained from the simulated BP signals are similar to values obtained in our previous experimental animal studies. Our results emphasize that nonlinearity in cardiovascular control is indeed a fundamental feature of the system.
Keywords :
bifurcation; biocontrol; blood pressure measurement; cardiovascular system; correlation methods; physiological models; pneumodynamics; α-sympathetic gain variations; bifurcation; blood pressure control; continuous nonlinear model; correlation dimension; human cardiovascular system; respiration; Animals; Bifurcation; Blood pressure; Cardiology; Cardiovascular system; Control systems; Humans; Nonlinear control systems; Nonlinear dynamical systems; Pressure control;
