Szafraniec Hannah M, Valdez José M, Iffrig Elizabeth, Lam Wilbur A, Higgins John M, Pearce Philip, Wood David K
Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, USA.
Department of Medicine, Emory University, Atlanta, Georgia, USA.
Lab Chip. 2022 Apr 12;22(8):1565-1575. doi: 10.1039/d1lc01133b.
Characterization of blood flow rheology in hematological disorders is critical for understanding disease pathophysiology. Existing methods to measure blood rheological parameters are limited in their physiological relevance, and there is a need for new tools that focus on the microcirculation and extract properties at finer resolution than overall flow resistance. Herein, we present a method that combines microfluidic systems and powerful object-tracking computational technologies with mathematical modeling to separate the red blood cell flow profile into a bulk component and a wall component. We use this framework to evaluate differential contributions of effective viscosity and wall friction to the overall resistance in blood from patients with sickle cell disease (SCD) under a range of oxygen tensions. Our results demonstrate that blood from patients with SCD exhibits elevated frictional and viscous resistances at all physiologic oxygen tensions. Additionally, the viscous resistance increases more rapidly than the frictional resistance as oxygen tension decreases, which may confound analyses that extract only flow velocities or overall flow resistances. Furthermore, we evaluate the impact of transfusion treatments on the components of the resistance, revealing patient variability in blood properties that may improve our understanding of the heterogeneity of clinical responses to such treatments. Overall, our system provides a new method to analyze patient-specific blood properties and can be applied to a wide range of hematological and vascular disorders.
血液系统疾病中血流流变学的特征对于理解疾病病理生理学至关重要。现有的测量血液流变学参数的方法在生理相关性方面存在局限性，因此需要新的工具来关注微循环，并以比整体流动阻力更高的分辨率提取特性。在此，我们提出一种方法，该方法将微流体系统、强大的物体跟踪计算技术与数学建模相结合，将红细胞流动剖面分离为主体成分和壁成分。我们使用这个框架来评估在一系列氧张力下，有效粘度和壁摩擦力对镰状细胞病（SCD）患者血液中整体阻力的不同贡献。我们的结果表明，在所有生理氧张力下，SCD患者的血液表现出升高的摩擦阻力和粘性阻力。此外，随着氧张力降低，粘性阻力比摩擦阻力增加得更快，这可能会使仅提取流速或整体流动阻力的分析产生混淆。此外，我们评估了输血治疗对阻力成分的影响，揭示了患者血液特性的变异性，这可能会增进我们对这类治疗临床反应异质性的理解。总体而言，我们的系统提供了一种分析患者特异性血液特性的新方法，可应用于广泛的血液学和血管疾病。
