主客观人眼波前像差测量的实验研究

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3.0 陈辉 2024-11-19 5 4 6.02MB 73 页 15积分
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I
摘 要
近些年来,由于人眼屈光手术的需求,波前像差测量仪器已经得到迅猛发展,
各种设计思想也层出不穷,但是现有的主观和客观的测量方法与测量仪器由于其
主观和客观的局限性,都不能很好的引导角膜屈光手术中的个体化切削。因此需
要发展一个结合主观测量的准确与客观测量的快速的真实人眼波前像差测量方
法。本论文是“人眼像差主客观检测系统关键技术研究”课题的一个重要组成部
分,该课题的主要思想在于将主观测量与客观测量相结合以获取最接近人眼实际
视觉效果的像差信息,以及可以用于人眼视力个性化矫正所需的矫正量信息。
本文详细介绍了波前像差仪的测量原理及国内外的发展状况、人眼的基本结
构及人眼像差来源,创新性地设计并研制了主客观相结合的人眼像差测量系统,
这种系统把客观测量和主观判断结合起来,充分发挥主观测量和客观测量两种方
法的优点。主客观相结合的人眼波前像差测量系统通过波前传感器与可变形镜及
屈光调节系统之间的闭路循环,实现了波面像差的实时测量与补偿。通过软件的
控制,可变形镜可以产生或补偿各种个性化的波面像差。在此基础上,被检者根
据视标的主观感受进行波前的精细调整,直至被检者获得最佳的视觉感受。而此
时使用合理的算法将屈光调节,可变形镜调节等各矫正量进行融合,可以得到适
于人眼视力个性化矫正所需的矫正量信息。
本文根据主客观人眼波像差测量系统的实际需要,以经济性,实用性为原则,
购买了大量元器件,逐步搭建了整个系统。在客观自适应光学系统中实现标准视
力表主观测试功能;搭建高精度的屈光调节系统,并实现波前像差自适应矫正的
闭路循环;并在使用模拟人眼进行测量的基础上进行了活体人眼的测量。在实验
过程中,于分光棱镜旁与人眼共轭位置增加一个标准反射镜,并重新设计了光源,
既方便了光路调整又能够消除系统本身自带像差;于波前传感器前添加滤光片,
并改变了测量的瞳孔尺寸,实现了在正常光照条件下的测量;使用光源预补偿、
长焦透镜汇聚光束与屈光调节系统相结合的手段缩小了测量大像差人眼时视网膜
处的激光光斑尺寸,提高了波前像差仪在测量大像差人眼时的分辨率及信噪比,
有效的扩大了像差仪的测量范围;改变制作参考图时的入射光强,避免了因为过
曝现象及质心定位算法而导致的误差;采用离轴入射法消除角膜噪声影响,提高
了点阵图的信噪比。
关键词:波前像差 波前像差仪 人眼 主观 客观 测量
II
ABSTRACT
Recently, for the requirement of refractory surgery, wavefront aberration
measurement instruments have improved rapidly, and many new design thoughts
appear from time to time. However, the objective or subjective ocular aberrometers
currently available in the market have their disadvantages and cannot guide
customerized treatment in the cornea refractory surgery well. So we need to develop a
new wavefront measurement that can combine both the quickness of objective
measurements and nicety of subjective measurements. This paper is an important
component of the project "Key Technique Research in Combined Subjective and
Objective Measurement System of Human Eye Aberration", the main thought of
which is to combine advantages of both subjective method and objective method, and
finally get a wavefront aberration that is closest to true human eye aberrations.
This paper particularly introduces the principle of wavefront aberrometers and
their current developments; it also tells the configuration of human eyes and explains
the source of human eye aberration; finally, it creatively designs and makes a
combined subjective and objective measurement of human eye aberrations, which
combines both objective measurement and subjective judgment, and fully uses
advantages of both methods. The ocular wavefront aberration measurement system
could be used to perform a real time measurement and correction of ocular wavefront
aberrations with the close-loop between the Hartmann-Shack wavefront sensor
diopter adjustment system and the deformable mirror. The special aberration could be
generated or compensated by controlling the deformable mirror. And the optimum
visual perception of the target could be realized with the subtle adjustment of the
wavefront which was within the optical path of view test target. Finally, we got an
ocular wavefront aberration data truly close to the fact, which can be used in
customized treatment surgery, by combining adjustment of diopter systems,
deformable mirror.
Considering to their practical usage and their costs, this paper bought a great
many components for the need of the whole system, and builds the whole system step
by step. We realize a view test which can achieve subjective judgment among the
adaptive optical beam path; build a high standard diopter adjustment system, and
achieve the close-loop for aberration’s adaptive compensation; test vivo eyes based on
III
the experiments on model eyes. During the experiment, we add a standard mirror and
improved the light source part, which makes the adjustment of the beam path more
convenient; add a light filter in front of the wavefront sensor, and change the
dimension of pupil that can be measured, which enables the measurement under
ordinary illumination circumstances; combine the pre-compensation, long focal length
lens and diopter adjustment system, which minimize the spot on retina when testing
high-power aberration human eye, and improves the measurement range of
measurement instrument; weaken the power of input laser when making reference
patterns, which avoids the error caused by over-exposure and spot-finding algorithm
of the software; uses off-axis illumination method, which eliminates the noise from
cornea, and improves the signal-to-noise ratio of the pattern.
Key word: wavefront aberration, wavefront aberrometers, ocular,
subjective, objective, measurement
IV
目录
中文摘要
Abstract
第一章 绪论 ........................................................ 1
§1.1 课题背景 ..................................................1
§1.2 国外人眼波像差测量发展现状 ................................2
§1.2.1 激光光路追迹技术 ................................... 2
§1.2.2 同步像差仪 ......................................... 3
§1.2.3 阴影像差仪 ......................................... 3
§1.2.4 哈特曼夏克传感器 ................................... 3
§1.2.5 塔尔博特传感器 ..................................... 4
§1.2.6 视网膜仪 ........................................... 4
§1.2.7 主观空间分辨屈光计 ................................. 4
§1.3 国内人眼波像差测量发展现状 ................................5
§1.4 课题选题意义和依据 ........................................5
§1.5 论文主要研究内容及结构 ................................... 6
第二章 人眼像差测量的基本原理 ...................................... 7
§2.1 人眼的基本结构及像差的来源 ................................7
§2.1.1 人眼的组成 ..........................................7
§2.1.2 人眼的光学结构 ......................................8
§2.1.3 人眼像差的来源 ......................................9
§2.2 视敏度测量 ...............................................10
§2.3 人眼波前像差测量系统基本理论 .............................12
§2.3.1 波前像差定义 ...................................... 12
§2.3.1 用 Zernike 多项式描述波前 .......................... 13
§2.3.2 Zernike 多项式与人眼波像差的对应关系 ...............14
§2.3.3 Zernike 模式法波前重构 .............................14
§2.4 总结 .................................................... 15
第三章 主客观相结合人眼像差测量系统的设计 ......................... 17
§3.1 主客观相结合的问题的提出 ................................ 17
§3.2 主客观相结合的人眼像差测量系统的设计思想 ................ 17
§3.2.1 自适应光学系统的基本概念 ...........................18
§3.2.2 主客观相结合人眼像差测量系统的原型设计 ............ 19
§3.2.3 具体测量方案的选择 ................................ 20
V
§3.3 像差仪设计基本原理 ...................................... 22
§3.3.1 哈特曼检测法 ...................................... 22
§3.3.2 哈特曼夏克波前传感器 .............................. 23
§3.3.3 哈特曼夏克的扩展 .................................. 23
§3.3.4 像差的基本补偿 .................................... 24
§3.3.5 高阶像差补偿 ...................................... 25
§3.3.6 球差补偿 .......................................... 27
§3.4 系统的设计 .............................................. 27
§3.4.1 望远系统 .......................................... 28
§3.4.2 光源部分 .......................................... 29
§3.4.3 屈光调节部分 ...................................... 31
§3.4.4 自适应光学部分 .................................... 32
§3.4.5 主观目标部分 ...................................... 34
§3.5 测量步骤 ................................................ 36
§3.6 总结 .................................................... 36
第四章 主客观相结合人眼像差测量系统的搭建 ......................... 37
§4.1 介绍 .................................................... 37
§4.2 标准反射镜的增加 ........................................ 38
§4.3 光源部分的改进 .......................................... 39
§4.3.1 扩束系统 .......................................... 39
§4.3.2 预补偿系统 ........................................ 39
§4.3.3 实际光源部分 ...................................... 40
§4.4 主观视标的显示 ...........................................40
§4.5 屈光调节功能测试 .........................................42
§4.6 可变形镜功能测试 .........................................44
§4.7 总结 .....................................................46
第五章 实验结果及误差来源讨论 ..................................... 47
§5.1 对模拟人眼进行的最初步的实验 .............................47
§5.2 活体人眼测量 .............................................48
§5.3 提高图像质量及稳定性的一些改进与设计 .....................50
§5.3.1 分光元器件的改进 ...................................50
§5.3.2 增加滤光片 .........................................51
§5.3.3 测量瞳孔尺寸的改变 .................................51
§5.3.4 预补偿系统的改进 ...................................52
VI
§5.3.5 参考图像质量的改进 .................................54
§5.3.6 离轴入射法的使用 ...................................55
§5.4 误差来源讨论 .............................................57
§5.4.1 关于波前像差仪的误差 .............................. 57
§5.4.2 关于标准面的误差 .................................. 58
§5.4.3 关于可变形镜误差 .................................. 59
§5.4.3 主观测量影响因素 .................................. 59
§5.4.4 其他误差 .......................................... 59
§5.5 总结 .................................................... 60
第六章 总结与展望 ................................................. 61
总结 .......................................................... 61
展望 .......................................................... 62
参考文献 .......................................................... 63
附录 ICE 制定的激光直接照射人眼的 MPE 标准 ..........................67
在读期间公开发表的论文和承担科研项目及取得成果 .................... 68
致谢 .............................................................. 69
摘要:

I摘要近些年来,由于人眼屈光手术的需求,波前像差测量仪器已经得到迅猛发展,各种设计思想也层出不穷,但是现有的主观和客观的测量方法与测量仪器由于其主观和客观的局限性,都不能很好的引导角膜屈光手术中的个体化切削。因此需要发展一个结合主观测量的准确与客观测量的快速的真实人眼波前像差测量方法。本论文是“人眼像差主客观检测系统关键技术研究”课题的一个重要组成部分,该课题的主要思想在于将主观测量与客观测量相结合以获取最接近人眼实际视觉效果的像差信息,以及可以用于人眼视力个性化矫正所需的矫正量信息。本文详细介绍了波前像差仪的测量原理及国内外的发展状况、人眼的基本结构及人眼像差来源,创新性地设计并研制了主客观...

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作者:陈辉 分类:高等教育资料 价格:15积分 属性:73 页 大小:6.02MB 格式:PDF 时间:2024-11-19

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