Yumnah Mohamied
Ph.D. Student

+44 (0)20 7594 5126
Room L57, Roderic Hill

I am currently a first year PhD student in the BioFlow research group in the Aeronautics Department. My research interests is focussed on the role played by blood flow dynamics in the mechanisms involved in the initiation of cardiovascular diseases such as atherosclerosis. Atherosclerosis is a disease characterised by the focal accumulation of lipids within the arterial wall, and it is this focal nature of the disease which may be related to the non-uniform shear stresses imposed on the wall by the spatially varying blood flow.

Several shear-derived haemodynamic wall parameters (HWP) have been developed to correlate with disease patterns (such as oscillatory shear index, and time-averaged wall shear stress), but these metrics do not distinguish between uniaxial and multi-directional flow patterns. Our group has recently proposed a new metric, namely the time-averaged transverse wall shear stress that captures multidirectional features of the blood flow. I am currently interested in understanding its dependence on flow parameters in order to identify its viability as a marker of disease.

Furthermore, mass transport of water and macromolecules towards, into and through the arterial wall is known to be involved in the initiation of atherosclerosis, although little understood. No methods of measurement yielding a detailed understanding of the transport of these macromolecules currently exist. This has spurred on many numerical studies of the mass transport processes in the cardiovascular system, but most of these models neglect the different layers and cellular make up of the arterial wall. I am currently involved in developing and using such a numerical model which does account for the heterogenous nature of the arterial wall. This will lead to an improved understanding of where within the wall atherogenic macromolecules become  trapped, and where within the cardiovascular system is there an increase in concentration of such macromolecules and by implication transport into the wall.

This advancement in our understanding of the factors involved in the initiation of the disease will, it is hoped, lead to the development of new diagnostic, preventative, and treatment strategies.