Case Study

Dr Katherine Fraser

Cardiovascular Mechanics and New Cardiac Assist Devices, Katharine Fraser, PhD

My group work on understanding the mechanics of the cardiovascular system and interactions with implanted devices. We use computational fluid dynamics to simulate blood flow in artificial hearts and ventricular assist devices and use the results for understanding what happens to the blood inside the devices, what happens to the body with a device implanted, and for designing new devices. We solve the fundamental equations of fluid flow and use these as the basis for biological models, for example of blood trauma and cardiovascular flow. We combine computational results with experimental measurements including dye washout and haemolysis testing in in vitro flow rigs. To understand more fundamental aspects of blood flow, such as how the complicated rheology of blood combines with the high shear stress, transient-turbulent flow regime, we use rheometry combined with direct numerical simulations.

One project we are currently working on is the NeoVAD, the world’s first fully implantable circulatory support device small enough for infants and small children. The device will be designed to stop the progression of advanced heart failure in paediatric patients, with the hope of enabling young children to live a near-normal life. The project is a collaboration with investigators in Texas, Australia and Japan and is funded by the US National Institutes for Health. The work we are doing at Bath is to use computational fluid dynamics to design and optimize the blade geometries and blood flow path. In addition to maximising efficiency, we need to consider the range of operating points required for a growing child, as well as minimizing all forms of blood trauma.