[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 T^]}Oy@e,J  
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。 see
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模型 0+b1vhQ  
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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。 )@bQu~Y  
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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. koi^l`B$  
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光源 0#^v{DC  
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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。 q'MZ R'<@  
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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。 D.XvG_  
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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。 \dQNLLg/  
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视网膜的散射 jo@J}`\Zt  
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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。 du^J2m{f  
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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。 k$^`{6l  
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脚本 ^y%T~dLkp'  
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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： c0u^zH<  
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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。 D d</`iUq  
余下的脚本计算与屈光度有关的所有参数。 tZG:Pr1U@  
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分析 n7-6- #  
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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。 ^DwYOo2B  
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脚本代码 0:Ol7  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. |# 2.Q:&  
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Dim entity As T_ENTITY `+Q%oj#FF  
Dim op As T_OPERATION N//KPh  
Dim mat As T_MODELMATERIAL yaH Zt`Y  
Dim A As Double jtc]>]6i  
Dim pupilDiam As Double 9mTJ|sN:e  
Dim eID As Long %OOl'o"V{s  
Dim parID As Long _zi|  
Dim count As Integer wDe& 1(T^  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double [3|P7?W/  
Dim tlens As Double, nlens As Double :X (=z;B;N  
Dim curv As Double, conic As Double ;@|n @ax  
Dim ok As Long kL"2=7m;  
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Sub Main Z}Ft:7   
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    '用户输入对话框 ^,T(mKS  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 HRfYl,S,  
        TextBox 220,21,40,21,.TextBox1 'default: 0 _>X+ZlpU
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 b!5~7Ub.No  
        OKButton 40,91,90,21 ,wAF:7'  
        CancelButton 190,91,90,21 vnZC,J `  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9m~p0ILh  
        TextBox 220,49,40,21,.TextBox2 'default: 4 o]I\6,T/|  
    End Dialog ]|PiF+  
    Dim dlg As UserDialog q'Tf,a  
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    ok = Dialog (dlg) 3m!X/u  
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    If ok=0 Then    'cancel button was pressed lchPpm9  
        Print "Execution cancelled." IKilr'  
        End P:MT*ra*,  
    End If ={@6{-tl  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ok\vQs(a  
    If dlg.TextBox1 = "" Then Od,qbU4O  
        A = 0           'Default accommodation 57  
    Else &powy7rR  
        A = CDbl(dlg.TextBox1) x\G'kEd  
    End If aNspMJ
 
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    If dlg.TextBox2 = "" Then O)n~](sC\  
        pupilDiam = 4   'Default pupil diameter V#gK$uv  
    Else $1L>)S  
        pupilDiam = CDbl(dlg.TextBox2) o~y;j75{.*  
    End If q Y?j#fzi  
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    Print " " y'nK>)WG4  
    Print "Accommodation = " & A & " Diopters" nBSYsp{  
    Print "Pupil Diameter = " & pupilDiam & " mm" xHLlMn4M  
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    ' Calculate new parameters with accommodation ~H<6gN<j(.  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness oDAXiY$u  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 3<f}nfB%r?  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 2*l/3VW  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U,{eHe ?>T  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens J$w<$5UY  
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    tlens = 3.767 + 0.04*A                  'Lens thickness V1`o%;j  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ,pQZ@I\z  
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    'Adjust parameters to account for accommodation ' ;FnIZ  
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    '************************************************************************* Vl=l?A8  
    'Aqueous thickness (Position of Lens) vm7z,FfN  
    '************************************************************************* +RMSA^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) SaAFz&WRl  
    GetCustomElement eID, entity 4=.89T#<  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Ru!iR#s)!  
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    ' Delete any shift(s) in z DIfaVo/"  
    count = 0 J~zUp(>K  
    While GetOperationCount(eID)>count dI@(<R  
        GetOperation eID, count, op :W.(S6O(  
        If op.Type="ShiftZ" Then {{D)YldtA  
            DeleteOperation eID,count r|fL&dtr  
            count=count-1 S\YTX%Xm}  
        End If U}e!Wjrc  
        count=count+1 mCsMqDH  
    Wend +-U- D?-  
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    'Set new shift in M2>Vj/  
    op.Type = "ShiftZ" =9boya,>  
    op.val1 = taq TA`1U;c{n  
    op.parent = parID *ebSq)  
    AddOperation eID, op c%2QZC  
    Print "Set aqueous humor thickness = " & taq-0.55 ;
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    '************************************************************************* [P=Jw:E  
    'Radius and conic constant of anterior lens +_?hK{Ib"  
    '************************************************************************* $m%fwB  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;4^Rx  
    GetConic eID, entity, curv, conic jrlVvzZ  
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    SetConic eID, entity, 1/Rant, CCant h-#6av:  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant \Fbv
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    '************************************************************************* q77;ZPfs8  
    'Radius and conic constant of posterior lens "3)C'WlEy/  
    '************************************************************************* x=hiQ>BIO0  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) j9x<Y]  
    GetConic eID, entity, curv, conic &
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    SetConic eID, entity, 1/Rpost, CCpost L%*!`T
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost szZr4y<8|1  
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    '************************************************************************* =)H.cuc  
    'Lens thickness (Position of posterior lens surface) @Q ]
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    '************************************************************************* g2LM_1\  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) BOb">6C  
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    ' Delete any z-shift(s) N=T<_`$5  
    count = 0 c?f4Q,%|  
    While GetOperationCount(eID)>count  N_kMK  
        GetOperation eID, count, op ??
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        If op.Type="ShiftZ" Then <y2U3;t  
            DeleteOperation eID,count _JzEGpeG  
            count=count-1 *KZYv=s,u  
        End If =V,mtT  
        count=count+1 EnKR%Ctw  
    Wend _UMg[Um  
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    'Set new z-shift }>pknc?  
    op.Type = "ShiftZ" '%s.^kn  
    op.val1 = tlens sQUM~HD\a  
    op.parent = parID 4x=v?g&  
    AddOperation eID, op L:KF_W.I+  
    Print "Set lens thickness = " & tlens E<{R.r  
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    '************************************************************************* >Eyt17_H"n  
    'Lens index of refraction Go`vfm"S  
    '************************************************************************* )al]*[lY  
    eID = FindMaterial( "Lens" ) y2Q&s9$Do  
    GetModelMaterial eID, mat =57>!)  
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    mat.Nd = nlens Dzpq_F!;V  
    SetModelMaterial eID, mat lK?uXr7^  
    Print "Set lens index of refraction = " & nlens dc+>m,3$  
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    '************************************************************************* (R[[Z,>w.  
    'Pupil diameter c?(4t67|  
    '************************************************************************* ^H p; .f.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 'Cb6Y#6  
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    'Adjust pupil diameter (trimming volume inner hole)
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 2prU  
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    ' Adjust pupil location to just in front of the lens \#8D>i?m  
    parID = FindFullName( "Geometry.Arizona Eye" ) 2 ~dE<}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) S*,17+6dV  
    count = 0 AwCcK6N1  
    While GetOperationCount(eID)>count -vAC"8)S  
        GetOperation eID, count, op prUN)r@U   
        If op.Type="ShiftZ" Then gT6z9  
            DeleteOperation eID,count k90YV(  
            count=count-1 BwN0!lsF3  
        End If CQc+#nRe  
        count=count+1 WJ]T\DI  
    Wend 0G(/Wb"/  
    op.Type = "ShiftZ" 2,y|EpG#  
    op.val1 = taq-0.01 [CTnXb  
    op.parent = parID mtpeRVcF  
    AddOperation eID, op H-!,yte  
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    Print "Set pupil diameter = " & pupilDiam }g@v`5  
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    'Update AZ Eye subassembly Description DcS+_>a\{l  
    eID = FindFullName( "Geometry.Arizona Eye" ) n.}ZkG0`  
    GetEntity eID, entity [DYQ"A=)d  
    entity.Description = "Accommodation = " & A & "D" mn'A9er  
    SetEntity eID, entity `{8K.(])s!  
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    Update %6t
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    Print "DONE!" #]-SJWf3  
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End Sub ^23~ZHu  
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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： mupT<_Y  
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Accommodation = 4 Diopters i[i4h"$0  
Pupil Diameter = 4 mm }czrj%6  
Set aqueous humor thickness = 2.81 XjBW9a  
Set anterior lens radius = 10.4 and conic constant = -2.375869 C;v.S5x  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &L3M]  
Set lens thickness = 3.927 hy9\57_#  
Set lens index of refraction = 1.42672 B 5L2<  
Set pupil diameter = 4 IM*y|UHt  
DONE! _OYasJUMG  
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