[技术]Arizona眼睛模型 [复制链接]

简介 0y3<Ho,+$  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 QFfKEMN  
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模型 f @cs<x  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 dTV:/QM  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. +HK)A%QI  
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光源 dLSnhZ  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 Y)@PGxjz  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 '1}rQqZ  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 1x07ua@(v  
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视网膜的散射 I@=h|GM  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 !j(KbAhWZ  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 oPNYCE  
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脚本 K]bS:[34 R  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： zJMKgw,i*  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 9ok|]d P  
余下的脚本计算与屈光度有关的所有参数。 HHZ!mYr  
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分析 K74oRKv  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 dW7dMx  
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脚本代码 6\,^MI  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 0iXqAa  
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Dim entity As T_ENTITY p8"(z@T  
Dim op As T_OPERATION 8{+~3@T  
Dim mat As T_MODELMATERIAL fnnwe2aso  
Dim A As Double 1|w,Z+/  
Dim pupilDiam As Double 73~Mq7~8  
Dim eID As Long :,q3?l6  
Dim parID As Long nu0bJ:0aLd  
Dim count As Integer 6sy%KO*A  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double [/uKo13  
Dim tlens As Double, nlens As Double b+p!{  
Dim curv As Double, conic As Double 8 (^2  
Dim ok As Long ;D8Nya>%  
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Sub Main e+R.0E  
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    '用户输入对话框 <Awx:lw.  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 jX&&@zMq  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Y0B*.H Ae  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g&0GO:F`  
        OKButton 40,91,90,21 8)POEY4  
        CancelButton 190,91,90,21 N~>?w#?J  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9jPb-I-   
        TextBox 220,49,40,21,.TextBox2 'default: 4 b$R>GQ?#  
    End Dialog deT
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    Dim dlg As UserDialog 9_>4~!x`  
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    ok = Dialog (dlg) wCt+{Y3T  
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    If ok=0 Then    'cancel button was pressed y]jh*KD[  
        Print "Execution cancelled." Ee|+uQ981>  
        End aY:(0en]&  
    End If Gm2rjpZeq  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 'c$9[|x  
    If dlg.TextBox1 = "" Then rFy9K4D  
        A = 0           'Default accommodation <dYk|5AdLF  
    Else Fc
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        A = CDbl(dlg.TextBox1) c&Zm>Qo[  
    End If =-VV`  
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    If dlg.TextBox2 = "" Then FoG<$9  
        pupilDiam = 4   'Default pupil diameter `X^e}EGWu  
    Else \34|9#*z-  
        pupilDiam = CDbl(dlg.TextBox2) )(L&+
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    End If Mc}x]j`f  
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    Print " " M<p)@p  
    Print "Accommodation = " & A & " Diopters" Y+jKP*ri  
    Print "Pupil Diameter = " & pupilDiam & " mm" kTk?[BK  
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    ' Calculate new parameters with accommodation Ksp;bfe  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness iE
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Y@4vQm+  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens >@L HJ61C  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens V0AX1?H~w  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens XGoy#h  
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    tlens = 3.767 + 0.04*A                  'Lens thickness $($SQZK&  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \S<5b&G  
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    'Adjust parameters to account for accommodation y%,BDyK  
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    '************************************************************************* Qm.kXlsDI  
    'Aqueous thickness (Position of Lens) 1}uDgz^  
    '************************************************************************* %pp+V1FH  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ( 7?%Hg  
    GetCustomElement eID, entity op-#Ig$#  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 0hkuBQb\  
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    ' Delete any shift(s) in z ;9PM?Iy[  
    count = 0 UH.cn|R  
    While GetOperationCount(eID)>count O$H150,Q  
        GetOperation eID, count, op dvD<>{U,8  
        If op.Type="ShiftZ" Then SHk[X ]Uo  
            DeleteOperation eID,count (6BCFl:/Q<  
            count=count-1 
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        End If |u{QI3#'  
        count=count+1 mb/[2y<  
    Wend !-c*lb  
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    'Set new shift in {Pb^Lf >  
    op.Type = "ShiftZ" K|G$s  
    op.val1 = taq C'._}\nX  
    op.parent = parID i-?zwVmn  
    AddOperation eID, op lz(,;I'x  
    Print "Set aqueous humor thickness = " & taq-0.55 jEsTw_  
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    '************************************************************************* V</T$V$  
    'Radius and conic constant of anterior lens 0'hxw3#  
    '************************************************************************* 
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) I{zE73  
    GetConic eID, entity, curv, conic i'wF>EBz  
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    SetConic eID, entity, 1/Rant, CCant C.E>)  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant k
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    '************************************************************************* u mlZ(??.  
    'Radius and conic constant of posterior lens 9@Sb! 9h  
    '************************************************************************* 3~</lAm;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) V@:=}*E  
    GetConic eID, entity, curv, conic 9yo[T(8  
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    SetConic eID, entity, 1/Rpost, CCpost P$/A!r  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost yl<$yd0Zdu  
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    '*************************************************************************
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    'Lens thickness (Position of posterior lens surface) |/^aLj^u  
    '************************************************************************* `U_>{p&x  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?gwbg*  
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    ' Delete any z-shift(s) #}7m'F  
    count = 0 eBTedSM?t  
    While GetOperationCount(eID)>count 2{kfbm-89t  
        GetOperation eID, count, op *rz(}(r  
        If op.Type="ShiftZ" Then $lAb6e$n  
            DeleteOperation eID,count \G=R hx f  
            count=count-1 jfPJ5]Z  
        End If ICbdKgLz  
        count=count+1 /B@%pq  
    Wend qb>r\bc  
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    'Set new z-shift ]a!; `m$  
    op.Type = "ShiftZ" dU>R<jl!$  
    op.val1 = tlens J s<MJ4r>/  
    op.parent = parID g~hk-nXL.  
    AddOperation eID, op /Np"J  
    Print "Set lens thickness = " & tlens `J#xyDL6?  
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    '************************************************************************* 6a]f
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    'Lens index of refraction K: o|kd  
    '************************************************************************* qVD!/;l  
    eID = FindMaterial( "Lens" ) =R;1vUio  
    GetModelMaterial eID, mat PtQ#  
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    mat.Nd = nlens QjjJtKz  
    SetModelMaterial eID, mat XBWSO@M'  
    Print "Set lens index of refraction = " & nlens '"]>`=R  
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    '************************************************************************* JeTrMa2  
    'Pupil diameter 5@>4)dk\  
    '************************************************************************* B,vHn2W  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &Wv`AoV  
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    'Adjust pupil diameter (trimming volume inner hole) ,gL)~6!A  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" &>zy_)  
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    ' Adjust pupil location to just in front of the lens E0)mI)RW.  
    parID = FindFullName( "Geometry.Arizona Eye" ) `k{ff  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) FQ|LA[~  
    count = 0 Hu9-<upc&  
    While GetOperationCount(eID)>count !OoaE* s  
        GetOperation eID, count, op GkGC4*n  
        If op.Type="ShiftZ" Then snTJe[^d  
            DeleteOperation eID,count K!-&Zv  
            count=count-1 :S99}pgY  
        End If OZC/+"\,  
        count=count+1 X\p`pw$  
    Wend JM+sHHs  
    op.Type = "ShiftZ" uU[[[LQq  
    op.val1 = taq-0.01 |Y8Mk2,s  
    op.parent = parID i_9Cc$Qh<  
    AddOperation eID, op zN)|g  
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    Print "Set pupil diameter = " & pupilDiam /[nZ#zj!3  
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    'Update AZ Eye subassembly Description LN~N Fjs  
    eID = FindFullName( "Geometry.Arizona Eye" ) C;)Xwm>e  
    GetEntity eID, entity 9-a2L JI  
    entity.Description = "Accommodation = " & A & "D" ,p*ntj{  
    SetEntity eID, entity VO @ 4A6  
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    Update x<{;1F,k3  
    Print "DONE!" ek(kY6x:  
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End Sub h$aew63  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： :_fjml/  
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Accommodation = 4 Diopters gf3u0' $  
Pupil Diameter = 4 mm +9 16ZPk  
Set aqueous humor thickness = 2.81 `u p-m=zA  
Set anterior lens radius = 10.4 and conic constant = -2.375869 - 5o<Q'(  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 _Qm7x>NT4  
Set lens thickness = 3.927 `uNvFlP  
Set lens index of refraction = 1.42672 y?*[}S  
Set pupil diameter = 4 _>jrlIfc  
DONE! %2Xus9;k#