眼轴及眼前节SS-OCT一体化成像系统  

Integrated imaging system of eye axis and anterior segment based on SS-OCT

作　　者：蔡怀宇[1] 张玮茜 韩晓艳[1] 汪毅[1] 陈文光 陈晓冬[1] Cai Huaiyu;Zhang Weiqian;Han Xiaoyan;Wang Yi;Chen Wenguang;Chen Xiaodong(Key Laboratory of Opto-Electronics Information Technology of Ministry of Education,College of Precision Instrument and Opto-Electronic Engineering,Tianjin University,Tianjin 300072,China;Shanghai Medi Works Precision Instrument Incorporated Company,Shanghai 200237,China)

机构地区：[1]天津大学精密仪器与光电子工程学院光电信息技术教育部重点实验室,天津300072 [2]上海美沃精密仪器股份有限公司,上海200237

出　　处：《红外与激光工程》2020年第4期173-181,共9页Infrared and Laser Engineering

基　　金：国家重点研发计划(2017YFC0109901);天津市自然科学基金(15JCQNJC14200)。

摘　　要：针对现有眼轴测量仪器无法同时实现大量程眼轴测量及眼前节成像的功能,设计了眼轴和眼前节同步测量的大量程扫频光学相干层析成像系统。该系统通过设计大量程扫频光源增加成像深度,并在外部设计搭建标定光路进行k域重采样以提高大量程干涉范围内的成像质量,从而在获取高精度眼轴信息的同时对眼前节成像;针对该系统OCT图像信噪比较低的问题,文中采用基于各向异性滤波的保边去噪算法对图像中的散斑噪声进行抑制以提高图像对比度。系统分别使用等比例人眼模型和离体鱼眼进行成像实验,实验结果表明:该系统成像深度可达到69 mm,在精准测量眼轴纵向五层结构的同时完成12 mm范围内的眼前节横向扫描,眼轴长度平均测量误差0.04 mm,成像时间约为0.45 s,满足临床医学应用中实时性的要求。A system of Swept-Source Optical Coherence Tomography for synchronous measurement of the eye axis with large imaging depth range and anterior segments was proposed to solve the problem that traditional ophthalmic axis measuring instruments can not achieve the functions of large imaging depth in axial measurement and imaging on anterior simultaneously. The proposed system increased the imaging depth by designing a infrared swept source with wide range. Then a calibrated optical path was built for k-domain resampling to improve the imaging quality in large range interference. Thus the high precision axial information and the anterior segment image could be obtained simultaneously. To solve the problem of low SNR of OCT images in this system, an edge-preserving denoising algorithm based on anisotropy filtering was proposed to suppress the speckle noise, which effectively improved the image contrast. Using the equal-proportion human eye model and vitro fish eye imaging respectively, the experimental result shows that the imaging depth of the system can reach 69 mm. The 12 mm anterior segment can be completely scanned in transverse direction, while the axial five-layer structure is accurately measured. The average measurement error of axial length is 0.04 mm, and the imaging time is about 0.45 s, which fulfil the real-time requirements of clinical medical application.

关 键 词：扫频光学相干层析成像 眼轴测量 眼前节成像 k域重采样 图像增强 

分 类 号：TN247[电子电信—物理电子学]