[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 B2G5hbaA  
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。 -[=AlqL  
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模型 h76NR  
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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。 YR|(;B  
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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. -?aw^du  
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光源 ^%oG8z,L  
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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。 )_9e@~,  
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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。 g<2lPH  
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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。 ti{H(;;@  
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视网膜的散射 Ez/\bE  
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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。 O^X[9vrW  
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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。 Sv~YFS :oy  
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脚本 <\1}@?NGC  
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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： \3H<z@;  
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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。 f MY;  
余下的脚本计算与屈光度有关的所有参数。 8!u/   
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分析 ,+ns {ppn  
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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。 Y!++CMzU  
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脚本代码 [2GXAvXsT  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ";wyNpb(  
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Dim entity As T_ENTITY Tjnt(5g  
Dim op As T_OPERATION 8- dRdQu]  
Dim mat As T_MODELMATERIAL [c&2i`C  
Dim A As Double ]j& FbP)3  
Dim pupilDiam As Double 5TXg;v#Z  
Dim eID As Long //\ds71h  
Dim parID As Long cT/3yf  
Dim count As Integer Z|2Eb*  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 0s860Kn  
Dim tlens As Double, nlens As Double _:wZmZU}  
Dim curv As Double, conic As Double 3C277nx  
Dim ok As Long 9 '2=  
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Sub Main "DVt3E  
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    '用户输入对话框 kx|me~I  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 yB-.sGu  
        TextBox 220,21,40,21,.TextBox1 'default: 0 84iJ[F
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [X;>*-  
        OKButton 40,91,90,21 X3P&"}a  
        CancelButton 190,91,90,21 R<Z^L~)  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |if'_x1V  
        TextBox 220,49,40,21,.TextBox2 'default: 4 jmkRP"ZnA  
    End Dialog 3H1Pp*PH  
    Dim dlg As UserDialog y7CWBTH0>  
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    ok = Dialog (dlg) HDyQzCG,  
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    If ok=0 Then    'cancel button was pressed e&d3SQ%  
        Print "Execution cancelled." Kn']n91m  
        End <e'P%tG'  
    End If :FnOS<_B  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 'KSa8;:=C  
    If dlg.TextBox1 = "" Then ]}'^`  
        A = 0           'Default accommodation ,,S9$@R  
    Else }.'Z=yy  
        A = CDbl(dlg.TextBox1) Zotz?jVVr  
    End If ?p(kh^z  
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    If dlg.TextBox2 = "" Then 0[.3Es:_  
        pupilDiam = 4   'Default pupil diameter ?RDO] I>  
    Else ~u!gUJ:  
        pupilDiam = CDbl(dlg.TextBox2) )B81i! q  
    End If QW2?n`Fa9-  
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    Print " " RYt6=R+f  
    Print "Accommodation = " & A & " Diopters" [KMS<4t'  
    Print "Pupil Diameter = " & pupilDiam & " mm" 9X3yp:>V  
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    ' Calculate new parameters with accommodation jA,|JgN|n  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness h77IWo6%  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 9/G!0uE  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ^+M><jE9  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Hr6wgYPi  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens }hCaNQ&jH  
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    tlens = 3.767 + 0.04*A                  'Lens thickness r ^MiRa  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Q3,=~}ZNK  
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    'Adjust parameters to account for accommodation ".E5t@ }?m  
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    '************************************************************************* Mb/L~gd"  
    'Aqueous thickness (Position of Lens) gH'_ymT= 3  
    '************************************************************************* /1[gn8V691  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) UQ~4c,  
    GetCustomElement eID, entity s@s/'^`  
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    parID = FindFullName( "Geometry.Arizona Eye" ) gD6tHg>_  
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    ' Delete any shift(s) in z ]H+{eJB7O  
    count = 0 5z~\5x  
    While GetOperationCount(eID)>count Px#$uU  
        GetOperation eID, count, op qOi5WX6F/  
        If op.Type="ShiftZ" Then U*qNix  
            DeleteOperation eID,count -;>#3O-  
            count=count-1 ib]vX-  
        End If (z2Z)_6L*L  
        count=count+1 {i>Jfl]G}  
    Wend thptm  
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    'Set new shift in z,
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    op.Type = "ShiftZ"  ,1 P[  
    op.val1 = taq ~ezCu
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    op.parent = parID sT`^ljp4  
    AddOperation eID, op AK*N  
    Print "Set aqueous humor thickness = " & taq-0.55 4\6:\  
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    '************************************************************************* ~{M@?8wi  
    'Radius and conic constant of anterior lens jo_ sAb  
    '************************************************************************* )* TF"  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Sl>>SP  
    GetConic eID, entity, curv, conic jV^C19  
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    SetConic eID, entity, 1/Rant, CCant ?'sXgo.}  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !
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    '************************************************************************* +j[`,5oS  
    'Radius and conic constant of posterior lens HabzCH  
    '************************************************************************* Go <'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) HE;V zR  
    GetConic eID, entity, curv, conic 6^E`Sa!s  
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    SetConic eID, entity, 1/Rpost, CCpost %!y89x=E  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost j[XYj6*d  
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    '************************************************************************* qS.)UaA  
    'Lens thickness (Position of posterior lens surface) n3ZAF'  
    '************************************************************************* xmr|'}Pt[  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) `f)(Y1%.  
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    ' Delete any z-shift(s) h/<=u9J  
    count = 0 (A{NF(   
    While GetOperationCount(eID)>count NfwYDY  
        GetOperation eID, count, op i2PZ'.sL  
        If op.Type="ShiftZ" Then zZ=$O-&%  
            DeleteOperation eID,count _ 08];M|  
            count=count-1 3.vgukkk5  
        End If aFY u}kl  
        count=count+1 _]|Qec)  
    Wend =_PvrB2'  
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    'Set new z-shift EGS%C%>l/o  
    op.Type = "ShiftZ" hz\WZ^  
    op.val1 = tlens <o0~H  
    op.parent = parID z[9UQU~x?  
    AddOperation eID, op /IR#A%U  
    Print "Set lens thickness = " & tlens 6OB",  
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    '************************************************************************* <>=mCZ2  
    'Lens index of refraction jN/ j\x'  
    '************************************************************************* ssl&5AS  
    eID = FindMaterial( "Lens" ) #3MKH8k&~  
    GetModelMaterial eID, mat qn"K
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    mat.Nd = nlens HZZDv+  
    SetModelMaterial eID, mat 2o5;Uz1{  
    Print "Set lens index of refraction = " & nlens `;F2n2@  
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    '************************************************************************* u7=T(4a  
    'Pupil diameter &5Y_>{,  
    '************************************************************************* - k`.j  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) it1/3y =]  
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    'Adjust pupil diameter (trimming volume inner hole) z%:&#1)  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ?CY1]d  
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    ' Adjust pupil location to just in front of the lens 8&E}n(XE  
    parID = FindFullName( "Geometry.Arizona Eye" ) CMl~=[foW  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) -MfQ&U  
    count = 0 *Km7U-BG  
    While GetOperationCount(eID)>count &erm`Ho  
        GetOperation eID, count, op T20VX 8gX  
        If op.Type="ShiftZ" Then )`?%]D  
            DeleteOperation eID,count ?+`xe{k  
            count=count-1 #jS[
  
        End If %Kto.Xq  
        count=count+1 DWf$X1M  
    Wend 5DFZ^~  
    op.Type = "ShiftZ" <z)E(J\  
    op.val1 = taq-0.01 g}Qx`65:  
    op.parent = parID \=nrt?  
    AddOperation eID, op ,rO[mNk9@  
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    Print "Set pupil diameter = " & pupilDiam |4C^$  
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    'Update AZ Eye subassembly Description =2 jhII  
    eID = FindFullName( "Geometry.Arizona Eye" ) &]iKriG  
    GetEntity eID, entity g>0vm2|  
    entity.Description = "Accommodation = " & A & "D" }5bM1h#z  
    SetEntity eID, entity qnIew?-*  
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    Update LP<<'(l`  
    Print "DONE!" )bDnbO$s_  
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End Sub C}"@RHEu  
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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： j_Nm87i]  
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Accommodation = 4 Diopters h-XY4gq/  
Pupil Diameter = 4 mm hh"-w3+  
Set aqueous humor thickness = 2.81 rt!r2dq"  
Set anterior lens radius = 10.4 and conic constant = -2.375869 !%S4n  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 2\@Z5m3B  
Set lens thickness = 3.927 D>kD1B1  
Set lens index of refraction = 1.42672 {
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Set pupil diameter = 4 "H+,E_&(  
DONE! e7k%6'@  
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