Comparison of measured and known motion signals in different sectors. A CM image was modified using image-processing methods with varying parameters to create a video resembling the contraction and relaxation of the cell. In the upper row are illustrated A: the sector division, B: the velocity vector field during the contraction, and C: the known displacement velocity. Since the artificial displacement has circular symmetry, a horizontal cross-sectional displacement is shown. D: The proposed method was applied to the video data and the signal marked with red was obtained. A blue signal illustrates the known displacement field.