Development of measurement techniques of three dimensional velocity around a microbe by using a differential interference contrast microscope

点击翻译按钮获取中文摘要

To measure velocity distributions around a microbe, the three dimensional Particle Tracking Velocimetry (3D PTV) with a Differential interference contrast (DIC) microscope has been developed. In this method, the properties of out-of-focus image of particle are used for estimation of distance from particle to focal plane. In the out-of-focus image of particle, a ring like image is generated around the center of the particle image and the diameter of the ring like image increases with the distance from the particle to focus plane. Experimental results show that the diameter of the ring like image is proportional to the distance from a particle to the focal plane.The proposed method has been applied to measurements of the Brownian motion of a particle in water. The Results show a good agreement with the theoretical prediction.