[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 A:N!H_x  
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。 |%$d/<<PZ  
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模型 Y~Zg^x2  
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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。 I(<1-3~  
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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. zm"&8/l  
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光源 
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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。 =_=jXWOQv  
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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。 aRfkJPPa[  
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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。 =w,%W^"E  
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视网膜的散射 k?1cxY s  
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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。 Wu%;{y~#}  
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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。 lAV6z%MmM  
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脚本 Ix-FJF-  
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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： SC"=M^E  
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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。 c7'I'~  
余下的脚本计算与屈光度有关的所有参数。 zLC\Rc4  
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分析 5>"-lB &  
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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。 !dSt
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脚本代码 -.i1l/FzP  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. IgQW 5E#  
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Dim entity As T_ENTITY r68'DJ&m3  
Dim op As T_OPERATION pX*Oc6.0mu  
Dim mat As T_MODELMATERIAL \P+lb-~\"  
Dim A As Double 2Cj?k.Zk  
Dim pupilDiam As Double rW
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Dim eID As Long `4gm'C  
Dim parID As Long +wgNuj0=*  
Dim count As Integer [#$z.BoEo  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double (KK9/k  
Dim tlens As Double, nlens As Double jun>(7  
Dim curv As Double, conic As Double QY/36gK  
Dim ok As Long w-
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Sub Main /`Yp]l  
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    '用户输入对话框 K9;pX2^z9  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 v;80RjPy>  
        TextBox 220,21,40,21,.TextBox1 'default: 0 k]] (I<2  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ix=HLF-0zC  
        OKButton 40,91,90,21 1ZOHyO  
        CancelButton 190,91,90,21 9pb4!=g*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k"LbB#Q  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ?ye)&  
    End Dialog `u3to{  
    Dim dlg As UserDialog 6NVf&;laQ  
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    ok = Dialog (dlg) ,q]Wi#  
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    If ok=0 Then    'cancel button was pressed xVao3+r  
        Print "Execution cancelled." >sv|  
        End NX4!G>v  
    End If %`t;5kmR  
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    'Assign accommodation and pupil diameter & use defaults if field left empty BQ2EDy=}6  
    If dlg.TextBox1 = "" Then @kK${  
        A = 0           'Default accommodation }xJ9EE*G/  
    Else rZ
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        A = CDbl(dlg.TextBox1) )cNG)F  
    End If b*LEoQSl0V  
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    If dlg.TextBox2 = "" Then D642}VD  
        pupilDiam = 4   'Default pupil diameter 7afD^H%  
    Else q
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        pupilDiam = CDbl(dlg.TextBox2) Wky=]C%  
    End If ?dP3tLR  
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    Print " " lG;RfDI-  
    Print "Accommodation = " & A & " Diopters" % < D  
    Print "Pupil Diameter = " & pupilDiam & " mm" Fy3&Emu  
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    ' Calculate new parameters with accommodation .9_]8T  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 3 [: x#r  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens qRT1Wre 3  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Gnop  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Y O;N9wu3f  
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    tlens = 3.767 + 0.04*A                  'Lens thickness |q"WJQ  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +h_'hz&HlS  
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    'Adjust parameters to account for accommodation /~)vma1<  
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    '************************************************************************* {Hm0Q  
    'Aqueous thickness (Position of Lens) _IBIx\F  
    '************************************************************************* ?W-J2tgss{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) C8>zr6)1  
    GetCustomElement eID, entity ,rVm81-2  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 'yxRz5  
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    ' Delete any shift(s) in z ]S4TX  
    count = 0 0Po",\^  
    While GetOperationCount(eID)>count KSU?Tg&JR  
        GetOperation eID, count, op -fIX6  
        If op.Type="ShiftZ" Then QNj hA'[T  
            DeleteOperation eID,count ":E 7#9  
            count=count-1 ?3~]H 
 
        End If m,NUNd#)\  
        count=count+1 G{ ~pA4  
    Wend 5 fY\0  
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    'Set new shift in o?@,f/"5  
    op.Type = "ShiftZ" V1 T?T9m  
    op.val1 = taq k0~mK7k  
    op.parent = parID ZnSDq_Uk  
    AddOperation eID, op 3on]#/"1b  
    Print "Set aqueous humor thickness = " & taq-0.55 ieXhOA  
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    '************************************************************************* &^$dHr6v  
    'Radius and conic constant of anterior lens vJ9Uw  
    '************************************************************************* ~&B{"d  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) N
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    GetConic eID, entity, curv, conic w=5D>]  
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    SetConic eID, entity, 1/Rant, CCant ,DsqKXSU  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant T^.;yU_B?  
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    '************************************************************************* T[*1*303  
    'Radius and conic constant of posterior lens
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    '************************************************************************* mpfc2>6Il.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) "\M16N  
    GetConic eID, entity, curv, conic bE:oF9J?  
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    SetConic eID, entity, 1/Rpost, CCpost 17g\XC@ Cl  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost I@IZ1 /J,r  
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    '************************************************************************* `(s&H8x#  
    'Lens thickness (Position of posterior lens surface) $GhdH)  
    '************************************************************************* d\&{Ev9v  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZYD
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    ' Delete any z-shift(s) @b[{.mU  
    count = 0 )N h67P3X"  
    While GetOperationCount(eID)>count :ad  
        GetOperation eID, count, op W FVx7  
        If op.Type="ShiftZ" Then , 6 P:S7  
            DeleteOperation eID,count (XW\4msB)I  
            count=count-1 *6D0>F  
        End If hbm%{*d  
        count=count+1 KP{|xQ>  
    Wend :{@&5KQ8)  
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    'Set new z-shift 0G`_dMN  
    op.Type = "ShiftZ" 2@K D '^(  
    op.val1 = tlens `B6~KZ  
    op.parent = parID e~C5{XEE  
    AddOperation eID, op 9}p>='  
    Print "Set lens thickness = " & tlens n,D~ whZx  
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    '************************************************************************* j\l9|vpp  
    'Lens index of refraction V5w00s5?%  
    '************************************************************************* K%AbM#o<  
    eID = FindMaterial( "Lens" ) YjaEKM8*  
    GetModelMaterial eID, mat [>+R|;ln  
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    mat.Nd = nlens Hl`S\  
    SetModelMaterial eID, mat PwP;+R};|  
    Print "Set lens index of refraction = " & nlens K;,zE6WD$$  
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    '************************************************************************* z}I=:  
    'Pupil diameter h
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    '************************************************************************* ?sfas57&y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 7)&}riQ  
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    'Adjust pupil diameter (trimming volume inner hole) Q72}V9I9  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" J2A+x\{<  
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    ' Adjust pupil location to just in front of the lens )~/;Xl#b-  
    parID = FindFullName( "Geometry.Arizona Eye" ) irj{Or^k  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e$HN/O  
    count = 0 #oBMA  
    While GetOperationCount(eID)>count
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        GetOperation eID, count, op zN}1Qh  
        If op.Type="ShiftZ" Then <T]BSQk  
            DeleteOperation eID,count QTZfe<m0  
            count=count-1 ( R2432R}J  
        End If /^_~NF#  
        count=count+1 5G5P#<Vv  
    Wend qKoD*cl)Za  
    op.Type = "ShiftZ" tQ!p<Q= $)  
    op.val1 = taq-0.01 @JJ,$?  
    op.parent = parID Axb,{X[6g  
    AddOperation eID, op 0\fV'JDOR  
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    Print "Set pupil diameter = " & pupilDiam LxD >eA  
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    'Update AZ Eye subassembly Description fL^+Qb}  
    eID = FindFullName( "Geometry.Arizona Eye" ) h)S223[  
    GetEntity eID, entity $ = uz  
    entity.Description = "Accommodation = " & A & "D" h#_KO-#.[  
    SetEntity eID, entity w-f[h  
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    Update )6K Q"*  
    Print "DONE!" ]/byz_7]  
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End Sub 06hzCWm#  
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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： &8kc0Z@y  
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Accommodation = 4 Diopters +Fn^@/?yC  
Pupil Diameter = 4 mm ryhme\%l;f  
Set aqueous humor thickness = 2.81 Kob i!  
Set anterior lens radius = 10.4 and conic constant = -2.375869 kjCXP  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 |>w>}w`~  
Set lens thickness = 3.927 pwj?  
Set lens index of refraction = 1.42672 t9zPUR  
Set pupil diameter = 4 1oD1ia#  
DONE! a4'KiA2r  
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