[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 i
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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。 .Bxv|dji  
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模型 2LS
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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。 -0[?6.(s"  
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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. V<&x+?>S  
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光源 B3 fKb#T  
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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。 :u$nH9kwv  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 t[$C r;  
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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。 ' lt5|  
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视网膜的散射 .W4P/Pw'  
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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。 h"h3SD~  
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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。 Wp7lDx  
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脚本 Sg#$ B#g  
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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： p5RnFe
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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。 L'1!vu *Rg  
余下的脚本计算与屈光度有关的所有参数。 T!-*;yu  
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分析 b
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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。 )Z4i

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脚本代码 n1yIQ8F  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 2bu,_<K.  
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Dim entity As T_ENTITY 6}z-X*  
Dim op As T_OPERATION .|XG0M
 
Dim mat As T_MODELMATERIAL S($8_u$U  
Dim A As Double (
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Dim pupilDiam As Double =@e3I)D#?i  
Dim eID As Long !{u`}:\  
Dim parID As Long dWc'RwL  
Dim count As Integer nZtMF%j'  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &TgS$
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Dim tlens As Double, nlens As Double .wH`9aq;5@  
Dim curv As Double, conic As Double 6&8uLM(z  
Dim ok As Long D*T*of G  
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Sub Main u
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    '用户输入对话框 -BV8,1  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 0H9UM*O  
        TextBox 220,21,40,21,.TextBox1 'default: 0 dG8_3T}i  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *'i9  
        OKButton 40,91,90,21 RpmOg  
        CancelButton 190,91,90,21 nYFM^56>_  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {l0[`"EF  
        TextBox 220,49,40,21,.TextBox2 'default: 4 8]@$7hy8  
    End Dialog [SKN}:D  
    Dim dlg As UserDialog `[)!4Jb  
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    ok = Dialog (dlg) gT-"=AsxZQ  
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    If ok=0 Then    'cancel button was pressed ]z77hcjB1  
        Print "Execution cancelled." ID_#a9N  
        End `erKHZ]S  
    End If mz>GbImVD~  

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    'Assign accommodation and pupil diameter & use defaults if field left empty 5^5hhm4  
    If dlg.TextBox1 = "" Then m;4qs#qCg?  
        A = 0           'Default accommodation -~_[2u^3  
    Else 0s$;3qE  
        A = CDbl(dlg.TextBox1) `=Z3X(Kc  
    End If GQH15_  
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    If dlg.TextBox2 = "" Then 7 /6Zp?  
        pupilDiam = 4   'Default pupil diameter zJ*(G_H  
    Else 5:yRFzhqd  
        pupilDiam = CDbl(dlg.TextBox2) '.B5C
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    End If
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    Print " " H`bS::JI-  
    Print "Accommodation = " & A & " Diopters" g)mjw  
    Print "Pupil Diameter = " & pupilDiam & " mm" \=qZ),bU@  
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    ' Calculate new parameters with accommodation p![UOI"W  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness (Q?@LzCjy  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens :.P
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens JP,yRb\  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens *'cyFu$  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens T -p~8=I  
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    tlens = 3.767 + 0.04*A                  'Lens thickness k>)Uyw$!  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &[z<p  
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    'Adjust parameters to account for accommodation XW.k%H4@  
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    '************************************************************************* G]n_RP$G  
    'Aqueous thickness (Position of Lens) -pHUC't  
    '************************************************************************* yvWM]A  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 8F K%7\V  
    GetCustomElement eID, entity -A,UqEt  
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    parID = FindFullName( "Geometry.Arizona Eye" ) g#q7~#9  
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    ' Delete any shift(s) in z 8ZF!}kb0F  
    count = 0 wEF"
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    While GetOperationCount(eID)>count IhHKRb[  
        GetOperation eID, count, op 6rMXv0)  
        If op.Type="ShiftZ" Then M%YxhuT0  
            DeleteOperation eID,count ,4j^lgJ  
            count=count-1 D(WdI  
        End If 2~l+2..  
        count=count+1 (?xR<]~g*  
    Wend Z*+y?5+L"P  
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    'Set new shift in ^4Uk'T7V  
    op.Type = "ShiftZ" #p<(2wN  
    op.val1 = taq >a;LBQ0  
    op.parent = parID t)5.m}  
    AddOperation eID, op j+PLtE  
    Print "Set aqueous humor thickness = " & taq-0.55 C]Q`!e  

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    '************************************************************************* t*J?#r  
    'Radius and conic constant of anterior lens VHi'
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    '************************************************************************* X%$1%)C9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) +G6 Ge;  
    GetConic eID, entity, curv, conic . H}R}^  
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    SetConic eID, entity, 1/Rant, CCant rJ{k1H>  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant I7\T :Q[  
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    '************************************************************************* |\Q2L;4C  
    'Radius and conic constant of posterior lens {
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    '************************************************************************* <TTBIXV  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) AyNpY_B0c  
    GetConic eID, entity, curv, conic >`
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    SetConic eID, entity, 1/Rpost, CCpost <G0Ut6J>  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ,9M2'6=  
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    '************************************************************************* 9^&B.6!6  
    'Lens thickness (Position of posterior lens surface) g~2=he\C  
    '************************************************************************* }G "EdhSl  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) <J>k%,:B  
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    ' Delete any z-shift(s) (-],VB (+  
    count = 0 ,vo]WIQ\:  
    While GetOperationCount(eID)>count v cUGBGX_&  
        GetOperation eID, count, op 86eaX+F  
        If op.Type="ShiftZ" Then iL!4r]~H  
            DeleteOperation eID,count DS9-i2  
            count=count-1 6HPuCP  
        End If GO.7IL{{  
        count=count+1 Z^BZH/I?  
    Wend :*/g~y(fE  
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    'Set new z-shift liqVfB%  
    op.Type = "ShiftZ"  YCVT0d  
    op.val1 = tlens xLb=^Xjec  
    op.parent = parID 3<l}gB'S[  
    AddOperation eID, op x:Q$1&3N  
    Print "Set lens thickness = " & tlens
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    '************************************************************************* 7[mP@ {  
    'Lens index of refraction P#MUS_x  
    '************************************************************************* mHAfKB  
    eID = FindMaterial( "Lens" ) YS@TQ?  
    GetModelMaterial eID, mat H )>3c1  
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    mat.Nd = nlens {>PEl;,-  
    SetModelMaterial eID, mat N]14~r=  
    Print "Set lens index of refraction = " & nlens `e`DSl D>  
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    '************************************************************************* +*Fe   
    'Pupil diameter L&rtN@5;  
    '************************************************************************* pN_%>v"o  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ll[&O4.F  
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    'Adjust pupil diameter (trimming volume inner hole) Wsp c;]&  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" w ~"%&SNN  
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    ' Adjust pupil location to just in front of the lens \3]O?'  
    parID = FindFullName( "Geometry.Arizona Eye" ) 86 9sS
  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Jamt@=
  
    count = 0 EiaP1o  
    While GetOperationCount(eID)>count "Bwmq9Jq  
        GetOperation eID, count, op LitdO>%#2  
        If op.Type="ShiftZ" Then W'=}2Y$]u  
            DeleteOperation eID,count jse!EtB:  
            count=count-1 a\~118 !  
        End If )#1!%a
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        count=count+1 {;th~[  
    Wend $iMLT8U  
    op.Type = "ShiftZ" ~{);Ab.9+  
    op.val1 = taq-0.01
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    op.parent = parID ?Ok&,\F@E  
    AddOperation eID, op T@`
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    Print "Set pupil diameter = " & pupilDiam DajN1}]  
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    'Update AZ Eye subassembly Description ZR-64G=L,  
    eID = FindFullName( "Geometry.Arizona Eye" ) Xh}D_c  
    GetEntity eID, entity #
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    entity.Description = "Accommodation = " & A & "D" y"s
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    SetEntity eID, entity ?Z4%u8Krvz  
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    Update @/ nGc9h  
    Print "DONE!" Ml;` *;  
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End Sub @$t\yBSK  
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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： pq\N2d  
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Accommodation = 4 Diopters wr=KAsH<  
Pupil Diameter = 4 mm wf1p/bpf  
Set aqueous humor thickness = 2.81 C(h Td%  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Rj
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 {IvA 5^  
Set lens thickness = 3.927 F|R7hqf  
Set lens index of refraction = 1.42672 cH4PrMm&  
Set pupil diameter = 4 KZ%us6  
DONE! 5W&L cBB  
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