[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 nlB'@r  
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。 H[.)&7M\  
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模型 Dc0=gq0  
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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。 nV8'QDQ:Al  
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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. ~RVlc;W  
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光源 V$hL\`e  
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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。 "T=j\/Q  
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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。 !Np7mv\7  
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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。 _<f%== I'  
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视网膜的散射 ied1+H  
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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。 3?j:M]fR  
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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。 *e [*  
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脚本 KH#z
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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： ]a/d
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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。 %pjY^tM/  
余下的脚本计算与屈光度有关的所有参数。 F1BvDplQ>G  
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分析 IN3-ZNx  
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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。 ! x
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脚本代码 Mhn1-ma:  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. yHE\Q  
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Dim entity As T_ENTITY +mBS&FK  
Dim op As T_OPERATION &i3SB
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Dim mat As T_MODELMATERIAL |e!Y C iU  
Dim A As Double (&79}IEd  
Dim pupilDiam As Double _YlyS )#@  
Dim eID As Long afHRy:<+%  
Dim parID As Long e=h-}XRC  
Dim count As Integer T\Xf0|y  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double FWeUZI+  
Dim tlens As Double, nlens As Double 7l-MVn_8  
Dim curv As Double, conic As Double "Ai\NC  
Dim ok As Long -flcB|I`  
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Sub Main ]0<K^OIY  
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    '用户输入对话框 JtSwbdN  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ?`Z:vqp>Z  
        TextBox 220,21,40,21,.TextBox1 'default: 0 eb}XooX  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 - s'W^(  
        OKButton 40,91,90,21 1E!.E=Y?M  
        CancelButton 190,91,90,21 .s"Og;g  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 6wpu[  
        TextBox 220,49,40,21,.TextBox2 'default: 4 }U=}5`_]D  
    End Dialog G[ns^  
    Dim dlg As UserDialog 7./WS
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    ok = Dialog (dlg) /Bgqf,N |  
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    If ok=0 Then    'cancel button was pressed FT>>XP8  
        Print "Execution cancelled." 3%r/w7Fc  
        End e~*tQ4  
    End If NApy(e5%  
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    'Assign accommodation and pupil diameter & use defaults if field left empty U.Vn|s(`z  
    If dlg.TextBox1 = "" Then +MHIZI  
        A = 0           'Default accommodation ;uc3_J]  
    Else OR+_s @Yg  
        A = CDbl(dlg.TextBox1) WU=EJY}#n  
    End If #]^C(qmb:  
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    If dlg.TextBox2 = "" Then
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        pupilDiam = 4   'Default pupil diameter |Wck-+}U  
    Else 5`&@3 m9/  
        pupilDiam = CDbl(dlg.TextBox2) #F3'<(j  
    End If N!<l~[rc  
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    Print " " ODKh/u_  
    Print "Accommodation = " & A & " Diopters" $<=d[6  
    Print "Pupil Diameter = " & pupilDiam & " mm" }+S
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    ' Calculate new parameters with accommodation n>B ,O  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness .K-d
 
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens OXZK|C;M}  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 7s%1?$B  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ?HOnDw.v1  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens  )bYOy+2g  
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    tlens = 3.767 + 0.04*A                  'Lens thickness D|$0~1y  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction FeZWS>N  
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    'Adjust parameters to account for accommodation N`,,sw  
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    '************************************************************************* FmF[S&gFRs  
    'Aqueous thickness (Position of Lens) p]~PyzG!  
    '************************************************************************* .#sX|c=W  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) VR_/Vh
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    GetCustomElement eID, entity `tT7&*Os  

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    parID = FindFullName( "Geometry.Arizona Eye" ) 0S+$l  
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    ' Delete any shift(s) in z T^+K`U  
    count = 0 gyy}-^`F  
    While GetOperationCount(eID)>count %< ;u JP K  
        GetOperation eID, count, op ;InMgo,  
        If op.Type="ShiftZ" Then A? jaS9 &)  
            DeleteOperation eID,count
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            count=count-1 6W]C`  
        End If afaQb  
        count=count+1 {#@[ttw$U  
    Wend dci,[TEGu  
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    'Set new shift in S+eu3nMq  
    op.Type = "ShiftZ" 6v}q @z  
    op.val1 = taq /IX555/dR1  
    op.parent = parID pFu!$.Fr  
    AddOperation eID, op is%ef  
    Print "Set aqueous humor thickness = " & taq-0.55 2.@IfBF6  
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    '************************************************************************* e<A>??h^  
    'Radius and conic constant of anterior lens (B@\Dw8^  
    '************************************************************************* ^xgPL'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) EN}4-P/
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    GetConic eID, entity, curv, conic 6&LmR75C  
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    SetConic eID, entity, 1/Rant, CCant /{[tU-}qJ  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant F$|d#ny  
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    '************************************************************************* cuf]-C1_  
    'Radius and conic constant of posterior lens - ?  i  
    '************************************************************************* "~Kph0-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +>Y]1IlI  
    GetConic eID, entity, curv, conic J5f}-W@  
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    SetConic eID, entity, 1/Rpost, CCpost QR-pji y  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost sQrM"i0Y>  
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    '************************************************************************* \7o7~pll  
    'Lens thickness (Position of posterior lens surface) |hDN$By  
    '************************************************************************* YiL^KK  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZRr.kN+F  
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    ' Delete any z-shift(s) %l%2 hvGZ  
    count = 0 7a/ BS(kq<  
    While GetOperationCount(eID)>count ]}&HvrOld  
        GetOperation eID, count, op @o<B>$tbu4  
        If op.Type="ShiftZ" Then R$eEW"]  
            DeleteOperation eID,count CqX*.j{  
            count=count-1 ;kG"m7-/  
        End If HYJEz2RF  
        count=count+1 p~(STHDe#  
    Wend iK5[P  
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    'Set new z-shift OSJj^Y)W|  
    op.Type = "ShiftZ" X VH(zJ  
    op.val1 = tlens {?cF2K#  
    op.parent = parID h]Gvt 5  
    AddOperation eID, op -0k{O@l"  
    Print "Set lens thickness = " & tlens %bG\  
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    '************************************************************************* ;c@B+RquR  
    'Lens index of refraction nF,zWr[x  
    '************************************************************************* 9m"EY@-  
    eID = FindMaterial( "Lens" ) }1a(*s,s-^  
    GetModelMaterial eID, mat ['6Sq@c)  
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    mat.Nd = nlens eG dFupfz  
    SetModelMaterial eID, mat 3"Kap/[h  
    Print "Set lens index of refraction = " & nlens +QSH*(,  
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    '************************************************************************* (K ]wk9a  
    'Pupil diameter f$?`50D"1  
    '************************************************************************* &!+1GI9z  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) gEgd/Le  
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    'Adjust pupil diameter (trimming volume inner hole) u&f|z9  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" w`/~y   
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    ' Adjust pupil location to just in front of the lens 9'vf2) "  
    parID = FindFullName( "Geometry.Arizona Eye" ) 4
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #~r+Z[(,p  
    count = 0 xaq/L:I<  
    While GetOperationCount(eID)>count UnZc9 6  
        GetOperation eID, count, op dL1{i,M  
        If op.Type="ShiftZ" Then $/E{3aT@F2  
            DeleteOperation eID,count zP$"6~.  
            count=count-1 {3Dm/u%=9|  
        End If Q[T)jo,j%  
        count=count+1 ki?V eFp  
    Wend A#F6~QX(.9  
    op.Type = "ShiftZ" =6qSo @  
    op.val1 = taq-0.01 4Le{|B  
    op.parent = parID 9S5C{~P4  
    AddOperation eID, op #zb67mg~  
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    Print "Set pupil diameter = " & pupilDiam l5enlYH  
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    'Update AZ Eye subassembly Description OskQ[ e0  
    eID = FindFullName( "Geometry.Arizona Eye" ) zgxMDLH  
    GetEntity eID, entity T IyHM1+  
    entity.Description = "Accommodation = " & A & "D" j}G9+GX~,  
    SetEntity eID, entity pT:6A[&  
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    Update }C JK9*Z  
    Print "DONE!" oSO~72  
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End Sub FlbM(ofY  
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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： Q_k'7Z\g$  
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Accommodation = 4 Diopters &i*e&{L7  
Pupil Diameter = 4 mm TH~"y  
Set aqueous humor thickness = 2.81 [E qZj/  
Set anterior lens radius = 10.4 and conic constant = -2.375869 @8cn<+"b  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 }e>OmfxDBt  
Set lens thickness = 3.927 *M6j)jqV  
Set lens index of refraction = 1.42672 ]1q`N7  
Set pupil diameter = 4 Ed#Hilk'  
DONE!
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