Riegger L, Grumann M, Steigert J, Lutz S, Steinert C P, Mueller C, Viertel J, Prucker O, Rühe J, Zengerle R, Ducrée J
Laboratory for MEMS Applications, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 106, 79110 Freiburg, Germany.
Biomed Microdevices. 2007 Dec;9(6):795-9. doi: 10.1007/s10544-007-9091-1.
We present a novel concept to process human blood on a spinning polymer disk for the determination of the hematocrit level by simple visual inspection. The microfluidic disk which is spun by a macroscopic drive unit features an upstream metering structure and a downstream blind channel where the centrifugally enforced sedimentation of the blood is performed. The bubble-free priming of the blind channel is governed by centrifugally assisted capillary filling along the sloped hydrophilic side-wall and the lid as well as the special shape of the dead end of the two-layer channel. The hematocrit is indicated at the sharp phase boundary between the plasma and the segregated cellular pellet on a disk-imprinted calibrated scale. This way, we conduct the hematocrit determination of human blood within 5 min at a high degree of linearity (R(2) = 0.999) and at a high accuracy (CV = 4.7%) spanning over the physiological to pathological working range. As all processing steps including the priming, the metering to a defined volume as well as the centrifugation are executed automatically during rotation, the concept is successfully demonstrated in a conventional PC-CDROM drive while delivering the same performance (R(2) = 0.999, CV = 4.3%).
我们提出了一种新颖的概念，即通过在旋转的聚合物盘上处理人体血液，以通过简单的目视检查来测定血细胞比容水平。由宏观驱动单元驱动旋转的微流控盘具有上游计量结构和下游盲通道，血液在其中进行离心强制沉降。盲通道的无气泡灌注由沿倾斜的亲水性侧壁和盖子以及双层通道死端的特殊形状的离心辅助毛细管填充控制。血细胞比容在盘上印有校准刻度的血浆和分离的细胞沉淀之间的清晰相界处显示。通过这种方式，我们在5分钟内以高度线性（R(2) = 0.999）和高精度（CV = 4.7%）进行人体血液的血细胞比容测定，涵盖生理到病理工作范围。由于包括灌注、计量到定义体积以及离心在内的所有处理步骤在旋转过程中自动执行，该概念在传统的PC - CDROM驱动器中成功得到验证，同时具有相同的性能（R(2) = 0.999，CV = 4.3%）。
