小鼠视网膜光学相干层析成像系统的研制  

Development of an Optical Coherence Tomography System for Mouse Retina Imaging

作　　者：董荣耀 马艳红 宋天琦 周明亮 王帅[2] 张鹏飞 Dong Rongyao;Ma Yanhong;Song Tianqi;Zhou Mingliang;Wang Shuai;Zhang Pengfei(School of Optoelectronic Engineering and Instrumentation Science,Dalian University of Technology,Dalian 116024,Liaoning,China;Department of Ophthalmology,the Second Affiliated Hospital of Dalian Medical University,Dalian 116027,Liaoning,China)

机构地区：[1]大连理工大学光电工程与仪器科学学院,辽宁大连116024 [2]大连医科大学附属第二医院眼科,辽宁大连116027

出　　处：《中国激光》2023年第21期143-152,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金(62175024);大连理工大学引进人才科研启动项目(DUT21RC(3)001)。

摘　　要：光学相干层析成像(OCT)是一种高速、高分辨率的生物医学成像技术,可实现微米级分辨率和毫米级深度成像。宽带光谱仪是其核心器件,直接决定了系统的轴向分辨率。面向小鼠视网膜高精度成像需求,笔者设计了一套基于自制光谱仪的OCT系统,并提出了一种基于系统性能指标(轴向分辨率和灵敏度下降)的光谱仪标定方法。通过理论计算和仿真,确定了光学器件的参数,并搭建了包括透镜、光栅和线扫描相机等硬件的系统。利用实验数据和光谱仪标定方法对光谱仪性能进行评估,结果表明:系统的有效成像深度可达2.5 mm,轴向分辨率优于3μm,成像速率为100 kHz,成像范围内的灵敏度下降了23 dB,达到了OCT的应用需求。最后,将所搭建的光谱仪应用于小鼠视网膜成像实验,获得了良好的小鼠视网膜断层图像,并基于断层图像对两种不同小鼠视网膜各层的厚度进行了对比研究。Objective Optical coherence tomography(OCT)is a widely used imaging technique in retina research,with the spectrometer being a crucial component that determines the performance of spectral domain OCT(SD-OCT).While there are commercial spectrometers and systems available with a variety of options,they are often expensive and not customizable for specific light sources and applications.Thus,independently developing spectrometers and OCT systems could provide a better alternative.The calibration of a spectrometer is typically complex because it requires a standard light source,such as a mercury lamp,that must meet the specific requirements for calibration,including accurate spectral characteristics.Additionally,use of such a light source demands certain technical and operational expertise.Therefore,this paper proposes a practical calibration method for an OCT spectrometer based on a common OCT algorithm.As a result,the need for a standard light source is eliminated,and hence OCT spectrometer calibration is simpler and easier.Methods In this study,an SD-OCT system was built,incorporating a supercontinuum laser as the laser source.The corresponding wavelength range is 800-950 nm using filters.The low coherent light emitted by the laser is split into two beams through a fiber coupler.Each beam enters the sample arm and the reference arm,respectively.In the sample arm,the light passes through a twodimensional galvanometer,generating a scanning beam on the mouse retina in this work.The power of the beam at the mouse pupil was approximately 600μW,with the beam diameter of 0.93 mm.To minimize chromatic aberrations,the lenses used in both the sample arm and reference arm were paired appropriately.The reflected beams from the sample arm and the reference arm combine and interfere on a custom-built spectrometer.The spectrometer includes a transmission grating,a line CCD camera,and other optical devices.For spectrometer calibration,a mirror is placed at the retina plane,reflecting light back to the spectrometer similar to the

关 键 词：医用光学 光学相干层析成像 光谱仪 标定 视网膜成像 

分 类 号：TH773[机械工程—仪器科学与技术]