角膜地形图仪结构及背光系统的设计

发布时间：2018-04-30 15:22

本文选题：角膜地形图仪 + 背光系统　；参考：《浙江工业大学》2016年硕士论文

【摘要】：在测量人眼角膜地貌方面角膜地形图仪发挥了很大的作用,并成为各大医疗机构指定的检测仪器。通过该设备,临床医学可获得大量的先验信息,为一套完整的眼部手术计划提供了安全保障。市面上,在众多的角膜地形图仪相关产品中,以Placido盘原理作为主要技术的角膜地形图仪,在其对人眼角膜进行检测的过程中,对背光系统和机械结构的稳定性要求极高。本人对以Placido盘原理为技术依托的角膜地形图仪进行了研究,研究内容包括结构和背光系统的设计。首先,在对角膜地形图仪工作原理的充分了解的前提下,对其各个部件的功能做了充分的分析,利用三维制图软件UG和SolidWorks对其进行了外形结构设计,最终设计出两款结构方案。通过对比,最终选取了在外形结构设计上平面使用比较多的一款设计进行研究分析。在结构设计的过程中,UG主要用于外形结构的设计,而Solid Works主要用于二维图纸的生成,最终通过加工生产出样品。其次,在对角膜地形图仪的工作原理和结构充分了解之后,对背光系统中的漫反射材料,LED背光源,Placido盘面型环的分布以及LED光源的驱动电路进行了设计,并且在实验上对其加工工艺与系统构建完成了实现。所获得的投射照明系统实验结果表明:在主波长为625nm的AlGalnP红色LED面光源照明的情况下,采用椭球面型Placido盘,成像到CCD上的黑白条纹环满足了等间隔的均匀分布,环宽平均值为0.202mm,标准差为0.00473,Placido盘黑白条纹处的光强对比度达到25.7,以及光照强度均匀性可达91.6%。经过测试确定该系统的检测精度高达0.02D,较好地满足了角膜地形图仪对投射照明系统的高对比度,高均匀性及高精度的要求。
[Abstract]:Corneal topography has played an important role in the measurement of human corneal topography and has been designated as a testing instrument by major medical institutions. Through this device, a large amount of prior information can be obtained in clinical medicine, which provides a safety guarantee for a complete ophthalmic operation plan. In the market, among the related products of corneal topography, the principle of Placido disc as the main technology of corneal topograph, in the process of detecting human cornea, the stability of backlight system and mechanical structure is very high. In this paper, based on the principle of Placido disc, a corneal topographic instrument is studied, including the design of structure and backlight system. First of all, on the premise of fully understanding the working principle of corneal topography, the function of each part of corneal topography is fully analyzed, and the shape and structure of the instrument are designed by using 3D mapping software UG and SolidWorks, and finally two structural schemes are designed. Through comparison, we select a design which is used more frequently in the design of shape and structure to carry on the research and analysis. In the process of structural design, UG is mainly used in the design of shape structure, while Solid Works is mainly used in the generation of two-dimensional drawings, and finally samples are produced by processing. Secondly, after fully understanding the working principle and structure of the corneal topography instrument, the distribution of the LED backlight ring and the driving circuit of the LED light source are designed. In the experiment, the process and system construction are realized. The experimental results of the projective illumination system show that under the illumination of the AlGalnP red LED surface light source with the main wavelength of 625nm, the equal-spaced uniform distribution of the black and white stripe rings on the CCD can be obtained by using the ellipsoidal Placido disk. The average ring width is 0.20mm, the standard deviation is 0.00473g Placido disk, the contrast of light intensity is 25.7 at the black-and-white stripes of Placido disk, and the uniformity of light intensity can reach 91.6. The accuracy of the system is as high as 0.02D, which can meet the requirements of high contrast, high uniformity and high precision of corneal topography.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH786

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