Mathematical modelling of the human cardiovascular system during an exercise test of the lower limbs and the recuperation phase

The primary role of the cardiovascular system is to deliver a required amount of oxygen to various organs. These needs vary with time and depend on the vascular site. To maintain a required diffusion level of oxygen in the capillary networks, the cardiovascular system is controlled by regulation processes that maintain pressure and blood flow to the required physiological levels. The authors have developed a nonlinear hemodynamic model associated with a varying elastance model of the heart and four simple control processes acting on the heart rate and the vascular resistances. The computed results, showing variations of arterial mean pressure, heart rate and vascular resistances agree with the experimental data under resting conditions, during moderate exercise of 200 W and during the recuperation phase.