Omori Toshihiro, Hosaka Haruki, Imai Yohsuke, Yamaguchi Takami, Ishikawa Takuji
Department of Bioengineering and Robotics, Tohoku University, Aoba 6-6-01, Aramaki, Sendai, Miyagi, Japan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Jan;89(1):013008. doi: 10.1103/PhysRevE.89.013008. Epub 2014 Jan 13.
Red blood cell (RBC) deformability plays a key role in microcirculation, especially in vessels that have diameters even smaller than the nominal cell size. In this study, we numerically investigate the dynamics of an RBC in a thin micropore. The RBC is modeled as a capsule with a thin hyperelastic membrane. In a numerical simulation, we employ a boundary element method for fluid mechanics and a finite element method for membrane mechanics. The resulting RBC deformation towards the flow direction is suppressed considerably by increased cytoplasm viscosity, whereas the gap between the cell membrane and solid wall becomes smaller with higher cytoplasm viscosity. We also measure the transit time of the RBC and find that nondimensional transit time increases nonlinearly with respect to the viscosity ratio, whereas it is invariant to the capillary number. In conclusion, cytoplasmic viscosity plays a key role in the dynamics of an RBC in a thin pore. The results of this study will be useful for designing a microfluidic device to measure cytoplasmic viscosity.
红细胞（RBC）的可变形性在微循环中起着关键作用，尤其是在直径甚至小于标称细胞大小的血管中。在本研究中，我们对红细胞在薄微孔中的动力学进行了数值研究。红细胞被建模为具有薄超弹性膜的胶囊。在数值模拟中，我们采用流体力学的边界元法和膜力学的有限元法。细胞质粘度增加会显著抑制红细胞向流动方向的变形，而随着细胞质粘度的增加，细胞膜与固体壁之间的间隙会变小。我们还测量了红细胞的通过时间，发现无量纲通过时间相对于粘度比呈非线性增加，而对毛细管数不变。总之，细胞质粘度在薄孔中红细胞的动力学中起着关键作用。本研究结果将有助于设计一种测量细胞质粘度的微流控装置。
