Smith, B.W.Chase, GeoffNokes, R.I.Shaw, GeoffWake, G.C.2007-06-222007-06-222004Smith, B.W., Chase, J.G., Nokes, R., Shaw, G.M., Wake, G. (2004) Minimal Haemodynamic System Model Including Ventricular Interaction and Valve Dynamics. Medical Engineering and Physics, 26(2), pp. 131-139.1350-4533http://hdl.handle.net/10092/105doi:10.1016/j.medengphy.2003.10.001Characterising circulatory dysfunction and choosing a suitable treatment is often difficult and time consuming, and can result in a deterioration in patient condition, or unsuitable therapy choices. A stable minimal model of the human cardiovascular system (CVS) is developed with the ultimate specific aim of assisting medical staff for rapid, on site modelling to assist in diagnosis and treatment. Models found in the literature simulate specific areas of the CVS with limited direct usefulness to medical staff. Others model the full CVS as a closed loop system, but models were found to be very complex, difficult to solve, or unstable. This paper develops a model that uses a minimal number of governing equations with the primary goal of accurately capturing trends in the CVS dynamics in a simple, easily solved, robust model. The model is shown to have long term stability and consistency with non-specific initial conditions as a result. An “open on pressure close on flow” valve law is created to capture the effects of inertia and the resulting dynamics of blood flow through the cardiac valves. An accurate, stable solution is performed using a method that varies the number of states in the model depending on the specific phase of the cardiac cycle, better matching the real physiological conditions. Examples of results include a 9% drop in cardiac output when increasing the thoracic pressure from -4mmHg to 0mmHg, and an increase in blood pressure from 120/80mmHg to 165/130mmHg when the systemic resistance is doubled. These results show that the model adequately provides appropriate magnitudes and trends that are in agreement with existing data for a variety of physiologically verified test cases simulating human CVS functionenJournal ArticleFields of Research::320000 Medical and Health Sciences::321000 Clinical Sciences::321008 HaematologyFields of Research::320000 Medical and Health Sciences::320600 Medical Physiology::320603 Systems physiologyFields of Research::290000 Engineering and Technology::291500 Biomedical Engineering::290599 Biomedical engineering not elsewhere classified