Validation of Bulk Properties of Red Blood Cells in Simulations

In a simulation model used to optimize microfluidic devices, blood is modeled as a red blood cell suspension using a dissipative version of Immersed Boundary Method (DC-IBM). Red blood cells (RBCs) are represented by elastic objects embedded in the fluid flow. The cell model and its parameters were calibrated to lit real experiment with one cell, such as a stretching experiment [1], or an experiment with red blood cell flowing through a narrowed channel [2]. For the correctnes of the model it is necessary to maintain the bulk properties of the blood flow. To validate the model, we investigated the hemodynamic phenomenon occurring in the narrower vessels, specifically the formation of a cell-free layer (CFL). The blood flow in the microchannel is simulated with hematocrit values in the range of 5–15% with cells with varying degrees of deformability. The results confirm existence of the migration from the channel walls to the center, resulting in the formation of CFLs near the walls. In accord with biological experiments, we confirmed a decrease in CFL thickness with increasing hematocrit. The effect of cell deformability on CFL and cell trajectory was also examined. This may be useful for further statistical analysis or model validation.