The project will produce a simulation tool to study the human cardiovascular system, and will advance significantly the use of simulation within the bio-medical community at a time when the use of prostheses is increasing substantially and clinicians are participating as never before in the engineering of organ replacements. The increasing availability of relatively inexpensive High-Performance Computing and Networking (HPCN) means that these problems are, for the first time, tractable.
The target end-users are primarily those clinicians, clinical scientists and manufacturers developing artificial heart valves, heart pumps, stents and grafts. As an example of the severity of the clinical problems, in recent years several mechanical heart valve designs have been investigated because of catastrophic failure in patients. These investigations have highlighted the lack of a quantitative understanding of the opening and closing motions of the disc occluder. This project will provide the necessary analytical facility and will aid the understanding of the behaviour of existing disc valves as well as providing an essential element in the design of new devices. The concepts used to obtain this computational solution will provide an opportunity to study many other problems in the cardiovascular field where blood flow interacts with implanted devices, including stents, replacement vessels and the fully-mechanical heart. The resultant analysis system will have a significant opportunity for exploitation in other, unrelated, areas with similar types of problems.
Cardiovascular simulation is a coupled problem. Not only is blood an inhomogeneous, anisotropic, non-Newtonian fluid, but the boundaries of the flow (the arteries, veins, heart, etc.) are not rigid, and in many instances can have a pronounced effect on the flow which cannot therefore be predicted using rigid wall, or prescribed-boundary-motion approximations. So a multi-disciplinary approach must be adopted, and a focused consortium driven by a group of end-users, and clinical scientists, together with specialists in Stress Analysis and Computational Fluid Dynamics has come together to deliver the required technology. The approach taken is to enhance a commercially-available CFD code and a leading commercial stress analysis package, by integrating complementary functions to take account of the particular problems posed by cardiovascular simulations.
The project will develop a tool that will not only provide clinicians with hitherto unavailable insights into the various mechanisms involved, but also significantly aid in the design of cardiovascular prostheses generally. Additionally, it is anticipated that the regulatory authorities involved in validating prostheses will wish to use the system as a tool in issuing directives and validating the compliance of marketed prostheses.