3D Surface Measurement of Human Abdomen by Fourier Fringe Analysis and Chinese Remainder Theorem

摘要

Aiming at the breathing movement of the human abdominal surface during surgical treatment or radiation therapy, the three-dimensional(3D) dynamic measurement method was studied. This paper proposes a dynamic three-dimensional measurement method based on a 3D Fourier transform to obtain the wrapped phase and unwrap using the Chinese remainder theorem (CRT) to obtain the absolute phase. The three primary colors are used to compile the coding pattern, and the three-dimensional inverse Fourier transform is used to obtain the wrapped phase information. By increasing the time-dimensional filtering, the ringing effect is reduced, and the accuracy of the wrapped phase extraction is improved. When there is no interference, the root means square error does not exceed 0.006 rad, and the peak-to-valley error does not exceed 0.016 rad. Its fault tolerance ability is higher than the two-dimensional Fourier fringe analysis and three-dimensional Fourier fringe with other filters on the abdomen surface. A new method based on CRT is used to unwrap the wrapped phase. Under the limited conditions, the error of the absolute phase does not exceed the error of the wrapped phase. The simulation and actual measurement results show that the method in this paper can realize the 3D dynamic measurements of the human abdominal surface.