Abstract：
The biomechanical properties of blood have been used to detect haematological diseases and disorders. The simultaneous measurement of multiple haemorheological properties has been considered an important aspect for separating the individual contributions of red blood cells (RBCs) and plasma. In this study, three haemorheological properties (viscosity, time constant, and RBC aggregation) were obtained by analysing blood flow, which was set to a square-wave profile (steady and transient flow). Based on a simplified differential equation derived using a discrete circuit model, the time constant for viscoelasticity was obtained by solving the governing equation rather than using the curve-fitting technique. The time constant (λ) varies linearly with respect to the interface in the coflowing channel (β). Two parameters (i.e., average value: <λ>, linear slope: dλdβ) were newly suggested to effectively represent linearly varying time constant. <λ> exhibited more consistent results than dλdβ. To detect variations in the haematocrit in blood, we observed that the blood viscosity (i.e., steady flow) is better than the time constant (i.e., transient flow). The blood viscosity and time constant exhibited significant differences for the hardened RBCs. The present method was then successfully employed to detect continuously varying haematocrit resulting from RBC sedimentation in a driving syringe. The present method can consistently detect variations in blood in terms of the three haemorheological properties.
摘要：
血液的生物力学特性已用于检测血液疾病和病症。多种血液流变学特性的同时测量被认为是分离红细胞(RBC)和血浆的个体贡献的重要方面。在这项研究中,三种血液流变学特性(粘度，时间常数,和红细胞聚集）通过分析血流获得，设置为方波剖面(稳态和瞬态流动)。基于使用离散电路模型导出的简化微分方程，粘弹性的时间常数是通过求解控制方程而不是使用曲线拟合技术获得的。时间常数(λ)相对于共流动通道(β)中的界面线性变化。两个参数(即，平均值:<λ>,线性斜率：dλdβ）被新建议有效地表示线性变化的时间常数。<λ>表现出比dλdβ更一致的结果。为了检测血液中血细胞比容的变化，我们观察到血液粘度(即，稳定流)比时间常数(即，瞬态流)。对于硬化的红细胞，血液粘度和时间常数表现出显着差异。然后,本方法成功地用于检测由驱动注射器中的RBC沉降引起的连续变化的血细胞比容。本方法可以在三种血液流变学特性方面一致地检测血液中的变化。
