摘要
背景:目前的眼屈光度测量方法均采用红外LED发光二极管作光源,红外光通过人眼角膜、房水、晶状体、玻璃体以及视网膜,造成反射的眼底图像不均匀,边缘判别难免出现误差,影响测量结果。目的:为了解决人眼屈光度测量方法和精度问题,设计了一套基于图像处理的眼睛屈光度测量系统。方法:将六点红外光射入眼底,经光学系统接收成像在CCD上,首先利用自适应多阈值方法对图像进行二值化分割,然后用重心法求每个点的中心坐标,最后再用最小二乘拟合的方法计算眼睛屈光度。实验用标准模拟眼进行了测试,并同日本TPCON验光仪进行了比较。结果与结论:设计的眼睛屈光度测量系统测量精度能达到国家计量规定的±0.25m-1。避免了由于人眼系统结构造成CCD接受图像不均匀而导致的计算精度误差;系统结构简单,光源能量能满足需要,实验表明可以提高眼睛屈光度参数测量精度,利用该技术已经做出了样机。在医院临床快速检查、普查视力具有重要应用。不足之处在于结构简化,大屈光度测量容易造成误差,对光源同光学系统的同轴性要求高,这是以后设计和工艺需要改进的地方。
BACKGROUND：Recent methods for diopter measurement utilize the infrared LED light emitting diode as the light source.The infrared light passes through the cornea,the aqueous,the lens,the vitreous and the retina,and causes the uneven reflection image.The edge determination error is inevitable,and affects the measurement results.OBJECTIVE：To design a new measurement system of eye diopter based on image processing to improve precision of diopter measurement.METHODS：The infrared image of six dots was emitted in retina,and it was displayed on CCD through optical system.First,the binary image was divided up with adaptive multi-threshold method.Subsequently,the center coordinate was calculated by centroid method.Finally,the parameter of diopter was acquired by least-squares fitting.The standard analogue eye was used for testing,and the testing results were compared with that of the refractor made in Japan TPCON.RESULTS AND CONCLUSION：The precision of diopter measurement can meet the requirement of ±0.25 m-1 which is prescribed by National Metrology Bureau,and the error which caused by uneven image on CCD can be avoided.The structure of system is simple,and the light energy can meet the requirement.The experiment shows that the precision of diopter parameter can be increased,and the prototype has been made.In the hospital,the technology can be used in quick clinical examination and vision screening.However,the structure is too simple,and may lead to the error in large diopter measurement.The coaxial requirement of the light source and the optical system is high,which should be improved in future.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2010年第48期9020-9023,共4页
Journal of Clinical Rehabilitative Tissue Engineering Research
基金
科技部科技成果重点推广项目(2003EC000084)
太原市科技创业种子基金(082114)项目~~
