[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 &Q-[;  
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。 krQl^~@  
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模型 dWsT Jyx~  
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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。 5y1or  
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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. P &;y] ,)E  
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光源 xoqiRtlY:  
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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。 UJee&4C-y  
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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。 ^=eq .(>  
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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。 q+YuVQ-fx  
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视网膜的散射 [leW/2i  
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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。 'M~BE\  
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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。 2{Wo-B,wt~  
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脚本 \n[ 392  
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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： oS~}TR:}  
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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。 RS'} nY}  
余下的脚本计算与屈光度有关的所有参数。 |r5e{  
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分析 o:_^gJ+|  
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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。 {I`B[,*  
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脚本代码 W@l+ciZ_  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. p?;-!TUv  
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Dim entity As T_ENTITY {]=v]O|,  
Dim op As T_OPERATION $Z/klSEf  
Dim mat As T_MODELMATERIAL ,*7H|de7  
Dim A As Double 2-~a P  
Dim pupilDiam As Double lj)f4zu  
Dim eID As Long ^Z2kq2}a  
Dim parID As Long Yj) e$f  
Dim count As Integer cFLd)mt/  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double !L77y^oV  
Dim tlens As Double, nlens As Double -PM)EGSk{  
Dim curv As Double, conic As Double #Rc5c+/(  
Dim ok As Long )%s +?  
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Sub Main |=\91fP68`  
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    '用户输入对话框 X:Q$gO?[4  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Y&s2C%jT  
        TextBox 220,21,40,21,.TextBox1 'default: 0 6)ycmu;!$  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Uh.Sc:trA  
        OKButton 40,91,90,21 ;+ G9-  
        CancelButton 190,91,90,21 s;J\Kc?"|  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 z5 Bi=~=#  
        TextBox 220,49,40,21,.TextBox2 'default: 4 }w@gj"\H  
    End Dialog rR]-
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    Dim dlg As UserDialog k^^:;OR  
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    ok = Dialog (dlg) X/Y#U\  
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    If ok=0 Then    'cancel button was pressed }kE87x
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        Print "Execution cancelled." =2,0Wo]$  
        End `@|w>8bMz{  
    End If kg3ppt  
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    'Assign accommodation and pupil diameter & use defaults if field left empty )Pli})  
    If dlg.TextBox1 = "" Then &3Tx@XhO  
        A = 0           'Default accommodation 8%[HYgd5)  
    Else _UkmYZ/  
        A = CDbl(dlg.TextBox1) gLIT;BK  
    End If Jf)3< ~G  
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    If dlg.TextBox2 = "" Then oEu>}JD  
        pupilDiam = 4   'Default pupil diameter 1TjZ#yP%1  
    Else 2J<&rKCF  
        pupilDiam = CDbl(dlg.TextBox2) Pdw#o^Iq^  
    End If ,GrB'N{8e  
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    Print " " ,)h)5o(?  
    Print "Accommodation = " & A & " Diopters" }>&KUl  
    Print "Pupil Diameter = " & pupilDiam & " mm" JDv-O&]  
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    ' Calculate new parameters with accommodation W&(f&{A  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness . uR M{Bs  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens xMI+5b8  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens K)S;:MLG=  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens TJaeQqob  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens st/n"HQ  
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    tlens = 3.767 + 0.04*A                  'Lens thickness @u) 'yS  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction F Z!J  
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    'Adjust parameters to account for accommodation sG,+  
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    '************************************************************************* rg5]&<Vq8  
    'Aqueous thickness (Position of Lens) )NT5yF,m  
    '************************************************************************* ~|lIC !q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :eOR-}p'  
    GetCustomElement eID, entity u@=?#a$$  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Ht[{ryTxu  
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    ' Delete any shift(s) in z lj2=._@R  
    count = 0 ;/LD)$_  
    While GetOperationCount(eID)>count kWL.ewTiex  
        GetOperation eID, count, op [s
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        If op.Type="ShiftZ" Then u3ZCT" !  
            DeleteOperation eID,count 7Kf}O6nE  
            count=count-1 &ZJgQ-Pc(m  
        End If Veji^-0E  
        count=count+1 Zb''mf\  
    Wend xh0xSqDM  
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    'Set new shift in |n6Eg9  
    op.Type = "ShiftZ" bJ3(ckhq  
    op.val1 = taq *t9eZ!_f?  
    op.parent = parID &L4 q10-N
 
    AddOperation eID, op Zzj0\?Ul  
    Print "Set aqueous humor thickness = " & taq-0.55 Tby,J B^U  
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    '************************************************************************* orIQ~pF#  
    'Radius and conic constant of anterior lens \u{8Bak0  
    '************************************************************************* qv+R:YYOq  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) .mxTfP=9  
    GetConic eID, entity, curv, conic F#V q#|_)>  
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    SetConic eID, entity, 1/Rant, CCant "uD=KlA  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant w1|Hy2D`0  
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    '************************************************************************* r;qzo.  
    'Radius and conic constant of posterior lens j+^L~, S  
    '************************************************************************* 1BTIJ Gw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) &35|16z%@  
    GetConic eID, entity, curv, conic 8_we: 9A  
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    SetConic eID, entity, 1/Rpost, CCpost -50AX1h31:  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;IZ
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    '************************************************************************* l]#!+@  
    'Lens thickness (Position of posterior lens surface) ?m"|QS!!K  
    '************************************************************************* 'BqZOZw  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) wH6u5*$p  
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    ' Delete any z-shift(s) raB+,Oi$G  
    count = 0 3$p#;a:=n  
    While GetOperationCount(eID)>count Vk}49O<K/  
        GetOperation eID, count, op ,x_Z JL  
        If op.Type="ShiftZ" Then eD;6okdP  
            DeleteOperation eID,count <$E6oZ  
            count=count-1 ZX.TqvK/r  
        End If BWq/TG=>  
        count=count+1 8^yJ
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    Wend YD[H  
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    'Set new z-shift "pvZ,l>8f  
    op.Type = "ShiftZ" SGcBmjP  
    op.val1 = tlens Rp.W,)i  
    op.parent = parID f_6`tq m%  
    AddOperation eID, op ]]uHM}l  
    Print "Set lens thickness = " & tlens [ygF0-3ND  
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    '************************************************************************* ,=%nw]:  
    'Lens index of refraction 6Wf^0ok  
    '************************************************************************* [aW=  
    eID = FindMaterial( "Lens" ) QT!5l`  
    GetModelMaterial eID, mat V[hK2rVH.  
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    mat.Nd = nlens J !#Zi#8sF  
    SetModelMaterial eID, mat Fi;VDK(V9  
    Print "Set lens index of refraction = " & nlens T] | d5E  
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    '************************************************************************* `~F5wh~  
    'Pupil diameter Tj/GClD:%  
    '************************************************************************* s:|M].  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 3C^1frF  
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    'Adjust pupil diameter (trimming volume inner hole) _a'A~JY  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" H7&xLYQ2  
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    ' Adjust pupil location to just in front of the lens FxU'LN<;HY  
    parID = FindFullName( "Geometry.Arizona Eye" ) *i%quMv  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) %FA@)?~  
    count = 0 6Z! y  
    While GetOperationCount(eID)>count T0e<Slo~C  
        GetOperation eID, count, op < K%j  
        If op.Type="ShiftZ" Then *y7 $x
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            DeleteOperation eID,count T1 M
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            count=count-1 :,UN8L "  
        End If ?9KGnOVu  
        count=count+1 5M){!8"S)#  
    Wend ]H[8Z|i""  
    op.Type = "ShiftZ" *Xr$/N  
    op.val1 = taq-0.01 E`D%PEps+  
    op.parent = parID a39hP*  
    AddOperation eID, op ?p^2Z6J'$  
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    Print "Set pupil diameter = " & pupilDiam _m'ysCjA  
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    'Update AZ Eye subassembly Description >L>+2z  
    eID = FindFullName( "Geometry.Arizona Eye" ) ;#QhQx  
    GetEntity eID, entity zVaCXNcbo  
    entity.Description = "Accommodation = " & A & "D" RUXCq`)"<  
    SetEntity eID, entity *HlDS22  
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    Update 2
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    Print "DONE!" JLm @Ag  
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End Sub #gv4  
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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： vXcy#  
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Accommodation = 4 Diopters Yp5L+~J[  
Pupil Diameter = 4 mm Wmz`&nsn[  
Set aqueous humor thickness = 2.81 wK*PD&nN  
Set anterior lens radius = 10.4 and conic constant = -2.375869 R]L2(' B  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 =_-C%<4  
Set lens thickness = 3.927 +_mr  
Set lens index of refraction = 1.42672 }Ik1bkK  
Set pupil diameter = 4 >Y&KTSD"  
DONE! Ja [4A0.  
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