Modeling Heart Rate Variability using a Baroreflex Model

8 Modeling Heart Rate Variability using a Baroreflex Model 

Another approach to cardiovascular modeling uses the same dynamic model for the cardiovascular system. In addition, a rather simple model is used for the baroreflex (Akay, 2001 Cavalcanti and Belardinelli, 1996). This latter model is responsible for the spontaneous fluctuations that occur in heart rate and heart pressure. Non-linear relationships are assumed between cardiac period (s) and blood pressure (mmHg). In addition, a non-linear relationship between stoke volume (ml) and blood pressure can be assumed (mmHg). The relationship between cardiac period T and blood pressure P can be given by (Cavalcanti and Belardinelli, 1996)  

For the relationship between stoke volume SV and blood pressure P, the authors proposed the following relationship  

The non-linear relationship between cardiac period and blood pressure is shown in Fig. 18.12. 

The behavior of the cardiovascular system is approximated by a simple flow model as given by Eqn. (18.7). From this equation, it can easily be derived that  

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