Choi Yong-Seok, Lee Sang-Joon
Center for Bio-fluid and Biomimetics Research, Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea.
Appl Opt. 2009 Jun 1;48(16):2983-90. doi: 10.1364/ao.48.002983.
Measurement of blood flow with high spatial and temporal resolutions in a three-dimensional (3D) volume is a challenge in biomedical research fields. In this study, digital holographic microscopy is used to measure the 3D motion of human red blood cells (RBCs) in a microscale volume. The cinematographic holography technique, which uses a high-speed camera, enabled the continuous tracking of individual RBCs in a microtube flow. Several autofocus functions that quantify the sharpness of reconstructed RBC images are evaluated to locate the accurate depthwise position of RBCs. In this study, the squared Laplacian function yields the smallest depth of focus and locates the depthwise positions of RBCs with a root mean square error of 2.3 microm. By applying this method, we demonstrate the measurement of four-dimensional (space and time) trajectories as well as 3D velocity profiles of RBCs. The measurement uncertainties of the present method are also discussed.
在三维（3D）体积中以高空间和时间分辨率测量血流是生物医学研究领域中的一项挑战。在本研究中，数字全息显微镜用于测量微观尺度体积内人类红细胞（RBC）的三维运动。使用高速相机的电影全息技术能够在微管流中连续跟踪单个红细胞。评估了几种量化重建红细胞图像清晰度的自动聚焦功能，以确定红细胞在深度方向上的准确位置。在本研究中，平方拉普拉斯函数产生最小的焦深，并以2.3微米的均方根误差确定红细胞在深度方向上的位置。通过应用此方法，我们展示了红细胞的四维（空间和时间）轨迹以及三维速度剖面的测量。还讨论了本方法的测量不确定度。
