摘要
为实现简化的角膜曲率测量系统,提出一种以角膜反射成像为原理的角膜曲率计,其测量方法是将六个呈正六边形排布的点光源准直后投射到角膜前表面,角膜反射图像经物方远心光路成像在CMOS上;利用重心算法求出角膜反射图像中位于正六边形长对角线上的两个点光源的距离,进而求得角膜曲率。本文对系统的成像质量、测量范围和测量精度进行了理论分析,并且采用标准模拟眼和人眼进行实验,以验证理论分析结果。结果表明:本文设计的测量系统的角膜曲率半径测量范围为5.5 mm～11 mm(对应角膜屈光度30 m-1～60m-1),测量误差为±0.02mm。这将为自动角膜曲率计的设计及优化提供技术支持。
To realize a simplified keratometer,we proposed a design proposal based on corneal reflex imaging.Six pointolites which arranged in a regular hexagon were used to emit parallel light to the surface of a cornea and were reflected by the cornea.Then the image was captured by a telecentric optical system in the object space to a CMOS camera.In order to obtain the corneal curvature,the distance between two pointolites located on the regular hexagonal diagonal in the corneal reflection images were calculated by using the center of gravity algorithm.The imaging quality,measuring range and measuring precision of the system were theoretically analyzed,and the Ziess’s model eye and human eyes were used to conduct experiments to verify the theoretical analysis results.The experiment results have shown that the precision of the measurement error is±0.02 mm and the measurement range is from 5.5 mm to 11.6 mm(30 m^-1 to 60 m^-1 in diopter of cornea).The research will provide technical supports for the design and optimization of automatic keratometer.
作者
陈鹏
王成
郑刚
陈明惠
项华中
张大伟
Chen Peng;Wang Cheng;Zheng Gang;Chen Minghui;Xiang Huazhong;Zhang Dawei(Institute of Biomedical Optics & Optometry,School of Medical Instrument and Food Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Engineering Research Center of Optical Instrument and System in Ministry of Education,Shanghai Key Laboratory of Modern Optical System,School of Optical Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)
出处
《光电工程》
CAS
CSCD
北大核心
2019年第1期51-61,共11页
Opto-Electronic Engineering
基金
国家自然科学基金资助项目(61775140
61378060)~~
关键词
角膜曲率计
反射成像
远心系统
图像处理
keratometer
reflection imaging
telecentric system
image processing
