【作者】 王金华；

【导师】 李鹏程；

【作者基本信息】 华中科技大学 ， 光电信息工程， 2014， 硕士

【摘要】 组织粘弹性系数是反映组织、器官代谢与生理功能状态的重要参数，监测组织粘弹性系数对研究生物组织的生理变化与疾病诊疗具有重要意义。激光散斑衬比成像原理是通过图像传感器收集组织表面反射回来散射光得到二维散斑图，利用散斑衬比算法分析获得被测物体内散射粒子运动速度。本论文在此基础上，提出了基于激光散斑的组织弹性成像方法，相比于其他已有的组织弹性成像技术，具有非接触、宽场成像、价格低廉的优点，且测量结果不受组织光学特性参数的影响。本论文的主要内容如下：(1)提出一种基于激光散斑原理的组织弹性成像方法。首先，在改进的Voigt模型基础上，通过建立在脉冲力作用下组织表面瑞利波的运动方程，分析得到速度变化方程；其次，利用激光散斑衬比原理对粒子相对速度进行探测；最后，利用曲线拟合的方式得到组织本征频率和粘滞阻尼系数，最终计算得到组织相对粘弹性系数。(2)设计了组织弹性成像系统。针对组织弹性成像需要对各组成模块进行了器件选择，并对实验过程中参数的设置进行了分析和讨论。(3)通过生物组织仿体实验方法，对成像系统功能进行验证，并分析了组织光学特性参数对实验结果的影响。更多还原

【Abstract】 Tissue viscoelastic coefficient is a significant parameter that reflects the metabolic andphysiological functional state of tissue and organs. Measurement of Tissue viscoelasticcoefficient is of important significance in the study of tissue physiological variation anddisease prevention. Laser speckle contrast imaging is a method using the imaging sensor(CCD or CMOS) to collect the scattered light reflected from the tissue surface, forming atwo-dimensional speckle pattern and using speckle contrast algorithm analysis to get thevelocity fluctuations of the scattering particle. Based on this imaging technique, we proposea new tissue elasticity imaging method--laser speckle tissue elasticity imaging. Comparing toother existing tissue elasticity imaging technique, our method can achieve non-contact, fullfield imaging with high sensitivity and low cost, and the result is not influenced by tissueoptical parameters. The main contents of this paper are as follows:(1) We proposed a tissue elasticity imaging method based on the principle of laserspeckle. Tissue is modulated by external pulse force and then we use laser speckle contrastimaging to measure the propagation of Rayleigh wave which is generated from the tissuesurface. Afterwards the tissue eigenfrequency and damping coefficient are calculatedthrough curve fitting data processing method.(2) We designed a tissue elasticity imaging system. For the needs of tissue elasticityimaging, we selected suitable devices and set suitable parameters for different model withdifferent components.(3) We set tissue phantom experiment to verify the imaging system, and to analyse theinfluence of tissue optical parameters to the experimental results.更多还原