光学相干层析技术微流场三维可视化测速方法

为实现微流场3D 可视化速度测量,建立了基于光学相干层析技术的微粒子跟踪速度测量系统。对系统组成原理、微粒子图像提取、匹配和速度计算方法等进行研究。介绍了频域光学相干层析技术、微流场速度测量系统组成及对渗入微粒子的微流场扫描及三维成像方法。利用中值滤波、最大类间方差二值化和体积滤波等方法搜索流场中各个微粒子,实现全流场流动特性3D 可视化;利用微粒子之间距离、灰度二阶矩建立代价函数,对不同时刻扫描得到的微粒子进行匹配,根据微粒子三维坐标求其运动速度。对对流流场进行了测量,实现了微米级空间分辨的微粒子图像与速度矢量显示。适合于复杂微流场的三维速度检测,对微流动器件流动特性研究具有重要意义。

3D visualization velocimetry technique for microfluidic based on optics coherence tomography

In order to realize 3D visualization velocimetry of microfluidic, an micro-particle tracking velocity measurement system based on optics coherence tomography was established and the principles of the system, algorithms such as image extraction of micro-particles, matching, and velocity computation were investigated. First, velocity measurement system based on optics coherence tomography and scanning and imaging method were presented. Then, micro-particles in fluid were detected using median filtering, OTSU binarization method and volume filtering to realize 3D visualization of flow characteristics. Finally, to find an optimal matching of micro-particles, the cost function was defined using the quadratic distance between particles, as well as the quadratic differences in the intensity moment of order 2, and velocity was computed using 3D coordinates of particles. Experimental results such as 3D particle images, and velocity vector with micrometer spatial resolution in convective flow were given. It is important for the velocity measurement of the complex microfluidic and study of microfluidic devices.