基于粒子群优化算法的生物组织杨氏模量的重构.pdf

Journal of Southeast University ( English Edition) Vol. 22 , No. 2 , pp . 208 - 212 June 2006 ISSN 1003—7985 PSO algorithm for Young s modulus reconstruction Chen Min Wang Nan Tang Wencheng ( College of Mechanical Engineering, Southeast University, Nanjing 210096, China) Abstract:To get the guantitive value of abnormal biological tissues, an inverse algorithm about the Young*s modulus based on the boundary extraction and the image registration technologies is proposed. With the known displacements of boundary tissues and the force distribution, the Young*s modulus is calculated by constructing the unit system and the inverse finite element method ( IFEM) . Then a tough range of the modulus for the whole tissue is estimated referring the value obtained before. The improved particle swarm optimizer ( PSO) method is adopted to calculate the whole Yong*s modulus distribution. The presented algorithm overcomes some limitations in other Young*s modulus reconstruction methods and relaxes the displacements and force boundary condition reguirements. The repetitious numerical simulation shows that errors in boundary displacement are not very sensitive to the estimation of next process; a final feasible solution is obtained by the improved PSO method which is close to the theoretical values obtained during searching in an extensive range. Key words:Young*s modulus; inverse finite element method; particle swarm optimizer The abnormalities of biological tissues always in- al. [8] proposed the FEA-based modulus estimation duce changes in the elastic properties which are useful technigue, assuming all the displacement distribution as in diag