基于有限元分析的超声弹性成像技术的研究

发布时间：2018-05-14 20:28

本文选题：超声弹性成像 + Comsol　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：生物组织的弹性信息可以反映组织病变与否及病变程度，然而传统医学成像方法却不能直接反应组织的弹性信息。20世纪90年代初由日本学者Y.Yamakoshi与美国学者J.Ophir首先提出一种新的超声成像技术——超声弹性成像，其实质是超声组织定征技术的进一步拓展。超声组织定征技术是研究多种与生物组织的生理病理状态和组织结构相联系的超声学参量技术，其最终目的是判断生物组织的病理状态。超声弹性成像的基本原理是：将外加激励源作用于软组织上，组织受压后内部的弹性差异将会导致不同的响应，该响应包括组织受压位移形变大小、组织所受应力大小以及应变大小均有不同。本文以弹性力学为基础，利用有限元方法进行组织应变、应力的仿真分析研究。有限元分析采用低频声压为外加激励源，这样不仅可以改变组织的压缩量还保证在实验进行中组织的内部结构关系满足单纯的线弹性假设。对待研究组织利用Comsol和Field II软件进行模拟分析，获得组织的位移、应变以及应变的分布，为后续进行的超声弹性成像提供了重要的实验依据。论文提出利用Hermite插值方式对互相关函数进行插值算法，与常用的抛物线插值方式相比，提出的方法更能有效计算组织应变响应。
[Abstract]:The elastic information of biological tissue can reflect whether or not the tissue changes and the extent of the lesions. However, traditional medical imaging methods can not directly respond to the elastic information of tissue. In the early 1990s, a new ultrasonic imaging technique, called ultrasonic elastic imaging, was first proposed by Japanese scholar Y.Yamakoshi and American scholar J.Ophir. Its essence is the further development of ultrasonic tissue characterization technology. Ultrasonic tissue characterization is a kind of ultrasonic parameter technique which is related to the physiological and pathological state and structure of biological tissue. The ultimate purpose of ultrasonic tissue identification is to judge the pathological state of biological tissue. The basic principle of ultrasonic elastic imaging is that when the external excitation source is applied to the soft tissue, the elastic difference within the tissue after compression will lead to different responses, which include the deformation of the tissue under compression. The stress and strain of the tissue are different. In this paper, based on the elastic mechanics, the finite element method is used to simulate the microstructure strain and stress. In the finite element analysis, the low frequency sound pressure is used as the external excitation source, which can not only change the compression of the structure, but also ensure that the internal structure of the structure can satisfy the simple linear elastic hypothesis in the experiment. Comsol and Field II software are used to simulate and analyze the research tissue, and the displacement, strain and strain distribution of the tissue are obtained, which provides an important experimental basis for the subsequent ultrasonic elastic imaging. In this paper, the Hermite interpolation method is proposed to interpolate the cross-correlation function. Compared with the parabolic interpolation method, the proposed method is more effective in calculating the strain response of tissue.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R445.1

【参考文献】