This study is motivated by the development of a blood cell filtration device for removal of malaria-infected, parasitized red blood cells (pRBCs). The blood was modeled as a multi-component fluid using the computational fluid dynamics discrete element method (CFD-DEM), wherein plasma was treated as a Newtonian fluid and the red blood cells (RBCs) were modeled as soft-sphere solid particles which move under the influence of drag, collisions with other RBCs, and a magnetic force. The CFD-DEM model was first validated by a comparison with experimental data from Han et al. 2006 (Han and Frazier 2006) involving a microfluidic magnetophoretic separator for paramagnetic deoxygenated blood cells. The computational model was then applied to a parametric study of a parallel-plate separator having hematocrit of 40% with a 10% of the RBCs as pRBCs. Specifically, we investigated the hypothesis of introducing an upstream constriction to the channel to divert the magnetic cells within the near-wall layer where the magnetic force is greatest. Simulations compared the efficacy of various geometries upon the stratification efficiency of the pRBCs. For a channel with nominal height of 100 µm, the addition of an upstream constriction of 80% improved the proportion of pRBCs retained adjacent to the magnetic wall (separation efficiency) by almost 2 fold, from 26% to 49%. Further addition of a downstream diffuser reduced remixing, hence improved separation efficiency to 72%. The constriction introduced a greater pressure drop (from 17 to 495 Pa), which should be considered when scaling-up this design for a clinical-sized system. Overall, the advantages of this design include its ability to accommodate physiological hematocrit and high throughput - which is critical for clinical implementation as a blood-filtration system.

中文翻译：

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用于疟疾感染红细胞磁分离的微流体通道设计。

这项研究的动机是开发一种用于去除感染疟疾、寄生虫的红细胞 (pRBC) 的血细胞过滤装置。使用计算流体动力学离散元方法 (CFD-DEM) 将血液建模为多组分流体，其中将血浆视为牛顿流体，将红细胞 (RBC) 建模为移动的软球体固体颗粒在阻力、与其他红细胞碰撞和磁力的影响下。CFD-DEM 模型首先通过与 Han 等人的实验数据进行比较来验证。2006 年（Han 和 Frazier 2006）涉及用于顺磁性脱氧血细胞的微流体磁泳分离器。然后将计算模型应用于平行板分离器的参数研究，该平行板分离器具有 40% 的血细胞比容和 10% 的红细胞作为 pRBC。具体来说，我们研究了向通道引入上游收缩以转移磁力最大的近壁层内的磁性细胞的假设。模拟比较了各种几何形状对 pRBC 分层效率的影响。对于标称高度为 100 µm 的通道，增加 80% 的上游收缩将保留在磁壁附近的 pRBC 比例（分离效率）提高了近 2 倍，从 26% 到 49%。进一步添加下游扩散器减少了再混合，因此将分离效率提高到 72%。收缩引入了更大的压降（从 17 帕到 495 帕），在将此设计扩大到临床规模的系统时应考虑到这一点。全面的，