Modelling and control of the human cardiovascular system

Bed-rest leads to cardiovascular deconditioning and may induce a decline in stroke volume, cardiac output and oxygen uptake.Further, it increases the risk of orthostatic intolerance.In an early phase of rehabilitation, it is therefore important to prevent the development of cardiovascular deconditioning which can be done by verticalisation and mobilisation.In the future, the enhanced ERIGO tilt-table will be able to control physiological signals and hence, stabilise the patient's cardiovascular system.This thesis focuses on the control of heart rate and blood pressure by means of verticalisation (tilting) and mobilisation (stepping).In a first step, a cardiovascular non-linear model with two inputs (tilting and stepping) and three outputs (heart rate, systolic and diastolic blood pressure) is developed based on physiological principles and existing work.The model is then used for designing a model predictive controller which was found well suited for the given control problem.Five healthy subjects have been tested with three different configurations: isolated heart rate control, isolated blood pressure control and combined control.One patient has been tested with blood pressure control which yielded promising results.