Modelling of the baroreflex-feedback mechanism with time-delay.

The cardiovascular system is considered. A direct modelling of the non-linear baroreflex-feedback mechanism, including time-delay, is developed based on physiological theory and empirical facts. The feedback model is then evaluated on an expanded, but simple, non-pulsatile Windkessel model of the cardiovascular system. The stability of the entire model is analyzed and the effect of the value of the time-delay is investigated and discussed. The time-delay may cause oscillations. A finite number of stability switches may occur dependent on the value of the time-delay. The location of these stability switches turns out to be sensitive to the value of the parameters in the model. We suggest a simple experiment to determine whether or not the time-delay is responsible for the 10 second Mayer waves. Data from an ergometer bicycle test is used for evaluation of the model.