A Generic Closed-Loop Model for the Cardiovascular System Thermoregulation and Brain Activity under Physical Stress Conditions

In this study, a closed-loop model, which includes the cardiovascular, the respiratory and the thermoregulatory systems under physical stress conditions, is presented. The proposed model is based on a ‘classical’ approach first proposed in the 1970’s. Moreover, a simplified model to describe the brain activity, via EEG signals, is also included. The proposed model is based on a grey-box modelling approach, utilising several neural-fuzzy structures, which were used because of the sufficient level of details that they provide. A higher level, represented by a neural network, was hierarchically superimposed on the overall model to produce a ‘generic’ cardiovascular model which is able to predict a wide range of dynamics associated with previously ‘unseen’ (new) subjects. Model predictions proved very good when compared with the actual signals obtained under real-time conditions