In vitro blood flow in a rectangular PDMS microchannel:: experimental observations using a confocal micro-PIV system
In vitro blood flow in a rectangular PDMS microchannel:: experimental observations using a confocal micro-PIV system
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DOI：
10.1007/s10544-007-9121-z
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发表时间：
2008-04-01
影响因子：
2.8
通讯作者：
Yamaguchi, Takami
中科院分区：
文献类型：
--
作者：
Lima, Rui;Wada, Shigeo;Yamaguchi, Takami
微加工技术的进展引起了包括微循环在内的几个领域研究人员的注意。微流控装置有望提供强大的工具，不仅可以更好地了解微血管中血流的生物物理行为，还可以用于疾病诊断。这种用于生物医学应用的微流体装置必须与最先进的流量测量技术兼容，例如共焦微粒图像测速（PIV）。该共焦系统不仅能够以高的空间和时间分辨率量化微通道内的流动模式，而且还可以用于获得沿微通道深度沿着的几个光学切片图像的速度测量。在这项研究中，我们调查的能力，以获得速度测量使用生理盐水（PS）和体外血液中的矩形聚二甲基硅氧烷（PDMS）微通道（300 μ m宽，45 μ m深），使用共聚焦显微PIV系统。应用这种组合，在恒定的流速（Re = 0.02）的两种流体中进行的痕量粒子的测量接种在流中。通过在不同深度位置的连续测量获得速度分布，以获得关于两种流体流动的行为的三维（3-D）信息。一般来说，速度分布被发现是显着钝的中心区域，主要是由于低纵横比（h/w = 0.15）的矩形微通道。预测矩形微通道的理论模型对应的PS流体的实验micro-PIV结果相当不错。然而，对于具有20%血细胞比容的体外血液，在速度分布中发现小的波动。目前的研究清楚地表明，共焦micro-PIV可以有效地集成与PDMS微通道，并用于获得血液流速分布沿着的微通道的整个深度，因为其独特的3-D光学切片能力。讨论了PDMS微通道与玻璃毛细管相比的优缺点。
Progress in microfabricated technologies has attracted the attention of researchers in several areas, including microcirculation. Microfluidic devices are expected to provide powerful tools not only to better understand the biophysical behavior of blood flow in microvessels, but also for disease diagnosis. Such microfluidic devices for biomedical applications must be compatible with state-of-the-art flow measuring techniques, such as confocal microparticle image velocimetry (PIV). This confocal system has the ability to not only quantify flow patterns inside microchannels with high spatial and temporal resolution, but can also be used to obtain velocity measurements for several optically sectioned images along the depth of the microchannel. In this study, we investigated the ability to obtain velocity measurements using physiological saline ( PS) and in vitro blood in a rectangular polydimethysiloxane (PDMS) microchannel (300 mu m wide, 45 mu m deep) using a confocal micro-PIV system. Applying this combination, measurements of trace particles seeded in the flow were performed for both fluids at a constant flow rate (Re = 0.02). Velocity profiles were acquired by successive measurements at different depth positions to obtain three-dimensional (3-D) information on the behavior of both fluid flows. Generally, the velocity profiles were found to be markedly blunt in the central region, mainly due to the low aspect ratio (h/w = 0.15) of the rectangular microchannel. Predictions using a theoretical model for the rectangular microchannel corresponded quite well with the experimental micro-PIV results for the PS fluid. However, for the in vitro blood with 20% hematocrit, small fluctuations were found in the velocity profiles. The present study clearly shows that confocal micro-PIV can be effectively integrated with a PDMS microchannel and used to obtain blood velocity profiles along the full depth of the microchannel because of its unique 3-D optical sectioning ability. Advantages and disadvantages of PDMS microchannels over glass capillaries are also discussed.