Influence of shear rate on the optical properties of human blood in the spectral range 250 to 1100 nm
Influence of shear rate on the optical properties of human blood in the spectral range 250 to 1100 nm
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DOI：
10.1117/1.2799154
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发表时间：
2007-09-01
影响因子：
3.5
通讯作者：
Meinke, Martina
中科院分区：
文献类型：
--
作者：
Friebel, Moritz;Helfmann, Juergen;Meinke, Martina
根据 250 至 1100 nm 波长范围内的剪切率，确定血细胞比容 42.1% 的人红细胞的固有光学参数 - 吸收系数 mu(a)、散射系数 mu(s)、各向异性因子 g 和有效散射系数 mu'(s)。针对0至1000 s(-1)之间的不同壁面剪切速率，结合逆蒙特卡罗模拟，进行光透射率和反射率的积分球测量。随机定向的单元格显示最大 mu(a)、mu(s) 和 mu'(s) 值。细胞排列和伸长，以及剪切速率增加时的 Fahraeus 效应，导致这些值渐近减小。各向异性因子仅在 600 nm 以下显示此行为，具体取决于吸收率；在 600 nm 以上，g 几乎与剪切速率无关。 mu的减少与血红蛋白的吸收呈反比。与随机定向的细胞相比，聚集会不同程度地降低所有参数，具体取决于血红蛋白的吸收。可以评估集体散射现象、细胞内吸收和细胞形状的影响。 (C) 2007 年光电仪器工程师协会。
The intrinsic optical parameters-absorption coefficient mu(a), scattering coefficient mu(s), anisotropy factor g, and effective scattering coefficient mu'(s)-are determined for human red blood cells of hematocrit 42.1% dependent on the shear rate in the wavelength range 250 to 1100 nm. Integrating sphere measurements of light transmittance and reflectance in combination with inverse Monte-Carlo simulation are carried out for different wall shear rates between 0 and 1000 s(-1). Randomly oriented cells show maximal mu(a), mu(s), and mu'(s) values. Cell alignment and elongation, as well as the Fahraeus effect at increasing shear rates, lead to an asymptotical decrease of these values. The anisotropy factor shows this behavior only below 600 nm, dependent on absorption; above 600 nm, g is almost independent of shear rate. The decrease of mu's is inversely correlated with the hemoglobin absorption. Compared to randomly oriented cells, aggregation reduces all parameters by a different degree, depending on the hemoglobin absorption. It is possible to evaluate the influence of collective scattering phenomena, the absorption within the cell, and the cell shape. (C) 2007 Society of Photo-Optical Instrumentation Engineers.