Figure 4. RBC R2 measurements.
(a) Weekly R2 measurement of a healthy blood sample for up to three weeks of post storage. As the hRBCs age, the R2 value increased as much as 16.7% from day two to day 21. (b) The normalized spin-down R2 values of hRBCs and iRBCs for the blood samples collected at inlet, middle, and side outlets. However, for hRBCs, the side outlet R2 value is significantly higher than the inlet and middle R2. For healthy blood sample, the margination device also separates the stiffer old RBCs from the more flexible young RBCs. When the hRBCs are spiked with the presence of 0.0005% iRBCs, the R2 value of the side outlet increases further since the iRBCs are marginated towards the sidewalls.