基于傅里叶变换的细胞牵引力测量研究

为了更快、更直观地进行细胞牵引力的测量，提出了一种基于傅里叶变换的细胞牵引力测量方法。首先，对微柱阵列的像进行二维快速傅里叶变换得到其空间频谱；其次，选取一级衍射斑点中的一个斑点做快速傅里叶逆变换，得到微柱阵列的幅值分布图；最后，由幅值突变的分布情况及突变的剧烈程度得到微柱阵列偏移量的分布情况，再乘微柱刚度即可得到细胞力的分布。通过仿真实验探究了频点选择、滤波窗口大小、偏移点大小对实验结果的影响，在此基础上对细胞-微柱高倍显微图进行了测量。实验结果表明，该方法在结果呈现方面不亚于质心法，测得的各区域最大细胞力的相对误差在17.37%之内，各区域平均细胞力的相对误差在7.93%之内，运算速度也比质心法快近10倍。

Research on cell traction measurement based on Fourier transform

In order to measure the cell traction more quickly and intuitively, a measurement method based on Fourier transform was proposed. Firstly, the two-dimensional fast Fourier transform was applied to the image of the micro-column array to obtain its spatial spectrum. Then, one spot in the first-order diffraction spot was selected for the fast Fourier transform to obtain the amplitude distribution of the micro-column array. Finally, the distribution of the offset of the micro-column array could be obtained from the distribution of amplitude mutation and the severity of mutation, and then the distribution of cell force could be obtained by multiplying the stiffness of the micro-column. The influence of frequency point selection, filter window size and offset point size on the experimental results was investigated through simulation experiments. On this basis, the high-power micrograph of cell micro-column was measured. The experimental results show that this method is comparable to the centroid method in terms of the result presentation. The relative error of the maximum cell force measured in each region is within 17.37%, the relative error of the average cell force measured in each region is within 7.93%, and the operation speed is nearly 10 times faster than that of the centroid method.