基于声光成像的浑浊介质吸收系数测量  

Absorption Coefficient Measurement of Turbid Media Based on Acousto-Optical Tomography

作　　者：刘遥 覃诗译 张畅 刘丽娜 朱莉莉 Liu Yao;Qin Shiyi;Zhang Chang;Liu Lina;Zhu Lili(Fujian Provincial Key Laboratory of Photonics Technology,Key Laboratory of Opto-Electronic Science and Technology for Medicine of Ministry of Education,College of Photonic and Electronic Engineering,Fujian Normal University,Fuzhou 350007,Fujian,China)

机构地区：[1]福建师范大学光电与信息工程学院医学光电科学与技术教育部重点实验室福建省光子技术重点实验室,福建福州350007

出　　处：《光学学报》2024年第4期237-246,共10页Acta Optica Sinica

基　　金：国家自然科学基金青年科学基金(11804051);福建省自然科学基金(2022J01171)。

摘　　要：理论分析了浑浊介质的声光作用机制。采用COMSOL Multiphysics软件对组织中的声光作用过程进行了仿真,讨论了组织吸收系数与声光信号相对强度的关系。仿真结果表明,声光信号与入射光强呈线性递增关系,声光信号相对强度与介质吸收系数呈指数下降关系,实验结果与仿真结果相吻合。利用声光成像实验测量厚度为10 mm的浑浊介质的吸收系数,真实值与测量值最大绝对误差为0.082 cm^(-1),最大相对误差为9.3%。Objective The physiological state of human tissues and the lesions of tissues are found to be closely related to the optical properties of tissues.The accurate measurement of optical parameters of tissue determines optical diagnosis correctness and phototherapy effectiveness,which is particularly essential in medical applications.At present,the common methods for measuring the optical parameters of biological tissues are integrating sphere technique,diffusion optical tomography,fluorescence imaging,and optical coherence tomography.In these methods,the measurement depth is not deep enough,or the measurement accuracy is not good enough to meet the practical applications.Acousto-optical tomography(AOT)combines the high spatial resolution of ultrasound with the high sensitivity of optical detection to provide excellent imaging depth(cm)at high imaging resolution(submm).AOT employs the localization and modulation of focused ultrasound,and the localization and quantitative measurement of the absorption coefficient of turbid media can be realized.Finally,the limitation that other measurement methods cannot consider both measurement depth and measurement accuracy can be compensated.We obtain the quantitative relationship between the absorption coefficient of the turbid medium and the acoustic-optical signal by theoretical analysis and COMSOL simulation.Furthermore,the absorption coefficient of turbid medium is measured by the AOT experiment,which preliminarily verifies the feasibility of AOT in the measurement of the tissue absorption coefficient.Methods Based on the radiation transmission theory and the intensity modulation mechanism of acousto-optic interaction in a turbid medium,the analytical relationship between acousto-optic signals and medium optical parameters is obtained.The finite element simulation software COMSOL Multiphysics is adopted for simulation,the extrapolated boundary equation and diffusion approximation theory are utilized to define the light field,and the ultrasound theory is to define the sound fi

关 键 词：生物光学 声光成像 声光作用机制 吸收系数测量 

分 类 号：Q631[生物学—生物物理学] Q