Modélisation Bond Graph du système cardiovasculaire pour l'étude du système nerveux autonome

Abstract

A model of the cardiovascular system (CSV) that consists of the ventricle, the circulatory system and the regulation of the cardiac action is presented. The model of the ventricle includes a description of the electromechanical phenomena occurring during cardiac contraction. It explains the global behaviour of the heart and is coupled with a model of the circulation. The whole cardiovascular system is under the influence of a regulation model. In fact, the cardiovascular system is regulated by the Autonomic Nervous System (ANS). In this work, only the influence of the short-term regulation of blood pressure (the baroreflex) is considered. The model allows the simulation of various physiological tests of the ANS, like the tilt test or the Valsalva manœuvre. These tests are usually used with patients to detect some pathology (syncope for example). But the interpretation of the signals obtained (blood pressure, heart rate) is often difficult because of the complexity of the SCV. It is then possible to improve the comprehension of the interaction between the SCV and the ANS thanks to the model; and to give a physiological interpretation of the signals obtained with the tilt test and the Valsalva manœuvre.