Statistical dynamics of flowing red blood cells by morphological image processing
Original Entry by Michelle Borkin, AP225 Fall 2009
J. Higgins, D. Eddington, S. Bhatia and L. Mahadevan. PLoS Computational Biology, 5, e1000288, 2009.
This paper investigates the complex random motions of individual red blood cells to better understand the role of individual cell movements in nutrient transport, gas transport, clotting, and hematological diseases. With this microscopic view, versus studying just the bulk flow, they were able to see the importance of these random motions. For example, patients with sickle cell disease who have irregularly shaped cells, have decreased random cellular motions suggesting an increased risk of vessel occlusion. The experiments were conducted by passing blood through microfluidic devices with a cross-sectional area of 250 μm x 12 μm (red blood cells have a radius of ~4 μm and thickness of ~1-2 μm) thus confining the motion of the cells to one direction. Also, cells only in the middle fifth of the flow were studied since the shear rate (~10/sec) is in the human physiological range for microcirculation. This "quasi-2D" set-up allowed for easy video imaging of the cells and subsequent image analysis to determine the random motions.
viscous drag coefficient... rheology... pressure-driven soft concentrated suspensions... characteristic length and time scales... shearing... clotting... [still finishing this section!]