Tissue Young's Modulus Reconstruction Based On Particle Swarm Optimizer

The tissue's abnormalities always induce changes in Young's modulus which are available to diagnose diseases. With the development of medical imaging, more and more technologies are used in measuring abnormalities of almost all parts of the body. Based on it, how to measure tissue's Young's modulus will be the focus in our future work.An inverse algorithm about Young's modulus based on boundary extraction and image registration technologies is proposed in this paper. Since the boundaries of tissues and abnormalities, and the stress distribution are known, Young's modulus distribution could be estimated using inverse finite element method(FEM) and particle swarm optimizer (PSO).This paper mainly introduces how to implement the inverse algorithm using inverse finite element method and PSO. Meanwhile, a modified algorithm is proposed using in searching in small range. In the last part of this paper, the feasibility of the inverse algorithm and the modified algorithm, when the displacements of boundary elements have errors, is tested using computer simulation.Also,the distributions of different physical parameters, produced by deformations, are analyzed in this paper. By comparing the distributions of different physical parameters with distribution of Young's modulus, some internal rules will be found. It is helpful to quantitatively calculate the distribution of Young's modulus.