System dynamics modelling approach in Health Sciences. Application to the regulation of the cardiovascular function

Abstract

The understanding of complex biological systems performance is one of the key issues in physiology, and several computational methods based on computer simulation have been applied to determine the behaviour of nonlinear systems. System Dynamics is an intuitive modelling methodology based on qualitative reasoning, whereby a conceptual physiological model can be described as a set of cause–effect relationships between the physiological variables of a system, so that a set of dynamic equations describing the system behaviour quantitatively can be derived. This paper presents system dynamics modelling methodology and its application for short-term arterial pressure control exerted through the baroreceptor reflex over a multi-compartmental cardiovascular model under the OpenModelica object-oriented simulation environment. The performance of the controlled system is analysed by simulation in light of the existing hypothesis and validation tests previously performed, demonstrating the effectiveness of the short-term regulation mechanism under physiological and pathological conditions. The system dynamics can be viewed as a powerful and easy-to-use educational tool and useful in Health Sciences so as to explain the behaviour of a physiologic system under study.