Simulation of the long wavelength sound-wave CT using prior information

Acoustical Science and Technology

Yuukou Horita¹  Juzhong Dong¹  Tadakuni Murai¹ 

[1] Faculty of Engineering, Toyama University, 3190 Gofuku, Toyama, 930–8555 Japan

关键词: Sound-wave CT;    Finite element method;    Newton-Raphson method;    Prior information;    Regularization method;   

DOI  :  10.1250/ast.22.389

学科分类：声学和超声波

来源: Acoustical Society of Japan

【 摘 要 】

References(14)Cited-By(1)A simulation study about the CT technique employing a stationary sound wave with long wavelength is presented. The CT is an inverse and nonlinear problem, so that an iterative approach is inevitable. That is, starting an assumed density distribution, the field calculation is repeatedly made until a true density distribution is achieved. An inhomogeneous domain is divided into subregions in which the density is assumed to be constant. The Finite Element Method is used for calculating the acoustic field under the given particle velocity driving source and the Newton-Raphson method is used to update the initial density distribution by minimizing the scalar error between computed and measured field values. To cope with the ill-condition which essentially exist in the inverse problem, three kinds of methods are used comparatively to solve this problem. For getting a more exact reconstruction, a new algorithm employing prior information is proposed. The simulation results show that the proposed algorithm can reconstruct satisfactorily the density distribution image of the model by the proper selection of driving position and its frequency.

【 授权许可】

Unknown