Alterations in red blood cell (RBC) deformability modulate blood viscosity and the cell distribution in the microcirculation, which, in turn, regulate the flow resistance to meet the tissue perfusion requirement without excessive taxation of the heart. As such, there is significant clinical and scientific merit in measuring RBC deformability in a blood sample. However, it should be noted that current measurement methods are mainly based on bulk measurement techniques and thus only an ensemble averaged value can be obtained to describe the blood sample. These bulk level measurements are insensitive to changes in small subpopulations within the total RBC population. Thus, it has been infeasible to provide information about the variability of a parameter in the RBC population, which is of interest in this study. On the other hand, microfluidics offer the capacity for integrated, on-chip measurements at the single cell level to extract information on inherent cell-to-cell variations in an RBC population.
The aim of this project is to utilize a conventional cross-slot microfluidic platform (Cha, et al., 2012) to measure the deformability of single RBCs. Non-Newtonian viscoelastic cell focusing in a circular conduit will be employed to improve the focusing efficiency in the cross-slot region. A modified semi-automatic image analysis program will also be developed to allow for large data processing and analysis. The improved platform will be applied to measure RBCs under varying diabetic conditions.