Cardiovascular disease is the biggest cause of morbidity and mortality in Europe. Its study brings together experts from the physical and life sciences with clinical practitioners in the search for understanding of the complex processes underpinning cardio vascular physiology. This proposal seeks to develop an energetically consistent framework into which models of disparate processes on disparate time and length scales can be integrated to further this understanding. It would be unrealistic to expect this programme to pull together all multidisciplinary threads, but it can develop a coherent framework for cardiovascular simulation. It will focus on the integration of bond graph elements, representing system characteristics in a coherent and intuitive manner, with 3D computational models, providing detail of local stress distributions and flow structures. The bond graph framework offers the facility for ready and consistent integration of descriptors of mechanical, chemical, electrical and biological events.

The simulation environment will be exercised in the study of an important problem in cardiovascular mechanics, namely the evaluation of closure forces of heart valve prostheses. For mechanical heart valve prostheses these can be very high, and can lead to early failure and, in some cases, to local cavitation in the blood. There are currently no models that integrate the mechano-chemical characteristics of the ventricular wall with local haemodynamics to compute closure forces. All current sophisticated models (including fluid-solid interaction) require explicit definition of either ventricular motion or pressure. The success of this proposal hinges on the combination of the expertise of the applicant, in bond graph modelling, with that of the host institution , in finite element analysis, computational fluid dynamics and in computational simulation environment development. The host department is located in a teaching hospital and has major clinical collaborations.