[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 U=v>gNba  
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。 ,|f=2t+5X  
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模型 Dw=L]i :0v  
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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。 l@4pZkdq  
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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. ,]wab6sY  
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光源 2<7pe@c98  
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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。 b'(AVA  

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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。
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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:ot'(~0-  
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视网膜的散射 tE>FL  
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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。 %2RXrH2&H  
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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。 [voc_o7AI  
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脚本 =$}`B{(H  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： lC*xyOK  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 =Q"ths
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余下的脚本计算与屈光度有关的所有参数。 Bl)D/  
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分析 bO6z;
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 [3irr0D7l  
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脚本代码 zCq6k7u  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?@A@;`0Y  
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Dim entity As T_ENTITY GDj_+G;tO\  
Dim op As T_OPERATION }+ W5Snx  
Dim mat As T_MODELMATERIAL "6e3Mj\  
Dim A As Double .&=\ *cZc  
Dim pupilDiam As Double q89yW)XG  
Dim eID As Long lYS4Q`z$  
Dim parID As Long bq7()ocA  
Dim count As Integer GNG.N)q#C  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q2|6WE  
Dim tlens As Double, nlens As Double ?h7[^sxJ  
Dim curv As Double, conic As Double H
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Dim ok As Long z:n JN%Qb  
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Sub Main PzjIM!>  
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    '用户输入对话框 *nM.`7g*[  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 4J[bh  
        TextBox 220,21,40,21,.TextBox1 'default: 0 cP21x<n  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 _qit$#wK;  
        OKButton 40,91,90,21 X7aj/:fXe  
        CancelButton 190,91,90,21 Yk4ah$}%-^  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 gi A(VUwI>  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Xp^>SSt:4  
    End Dialog )sEAPIka  
    Dim dlg As UserDialog y9:o];/  
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    ok = Dialog (dlg) < Lrd(b;  
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    If ok=0 Then    'cancel button was pressed or`"{wop  
        Print "Execution cancelled." ]sI{+$~:c  
        End ^w RD|  
    End If YkV-]%c  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ,g)9ZP.F  
    If dlg.TextBox1 = "" Then )o_$AbPt  
        A = 0           'Default accommodation piUfvw  
    Else Zfr?(y+3  
        A = CDbl(dlg.TextBox1) "%t !+E>nr  
    End If /Hc0~D4|x  
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    If dlg.TextBox2 = "" Then \AR3DDm  
        pupilDiam = 4   'Default pupil diameter k.0pPl  
    Else HQ|{!P\/?U  
        pupilDiam = CDbl(dlg.TextBox2) _`94CC:  
    End If xeHqC9Ou  
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    Print " " Kib?JRYt  
    Print "Accommodation = " & A & " Diopters" In4T`c?kQ  
    Print "Pupil Diameter = " & pupilDiam & " mm" Z$@XMq!  
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    ' Calculate new parameters with accommodation hmd,g>J:<  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 2TC7${^9}J  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Yc'7F7.<6  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 4VL]v9  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens !NOvKC!  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens z[, `  
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    tlens = 3.767 + 0.04*A                  'Lens thickness -1u N Z{0  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ?+#E&F  
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    'Adjust parameters to account for accommodation 0ID 8L [  
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    '************************************************************************* T+/Gz'  
    'Aqueous thickness (Position of Lens) <BN)>NqM
 
    '************************************************************************* 'W j Q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) T%F8=kb-9  
    GetCustomElement eID, entity J_mpI.^Bsf  
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    parID = FindFullName( "Geometry.Arizona Eye" ) M:(k7a+[^  
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    ' Delete any shift(s) in z h^0!I TL^  
    count = 0 Z5{M_^  
    While GetOperationCount(eID)>count g<{W\VOPm  
        GetOperation eID, count, op #6JCm!s  
        If op.Type="ShiftZ" Then akQtre`5sd  
            DeleteOperation eID,count ^Q_0Zq^H  
            count=count-1 IV:Knh+ ?  
        End If T3{qn$t8  
        count=count+1 2S8/ lsB  
    Wend )P.|Xk:r  
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    'Set new shift in B)
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    op.Type = "ShiftZ" |^@TA
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    op.val1 = taq VG\ER}s&P  
    op.parent = parID ziy~~J  
    AddOperation eID, op 8DLMxG  
    Print "Set aqueous humor thickness = " & taq-0.55 T,gMc  
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    '************************************************************************* 15gI-Qb  
    'Radius and conic constant of anterior lens FUm-Fp  
    '************************************************************************* =N n0)l  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) gzHjD-g-<  
    GetConic eID, entity, curv, conic $0K9OF9$
 
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    SetConic eID, entity, 1/Rant, CCant Md[nlz  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant d8 ve$X  
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    '************************************************************************* Ybx4 Up@  
    'Radius and conic constant of posterior lens _&JlE$ua7  
    '************************************************************************* ^QV;[ha,o  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ^yu^Du  
    GetConic eID, entity, curv, conic 7IZ(3B<87t  
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    SetConic eID, entity, 1/Rpost, CCpost 4(YKwY2_L  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost iygdX2  
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    '************************************************************************* ">voi$Kzey  
    'Lens thickness (Position of posterior lens surface) .'7o,)pJ<  
    '************************************************************************* B
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) M* QqiE  
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    ' Delete any z-shift(s) &2#x(v  
    count = 0 P/Sv^d5=e  
    While GetOperationCount(eID)>count G m<t2Csn  
        GetOperation eID, count, op F=^vu7rf  
        If op.Type="ShiftZ" Then o~^hsm[44J  
            DeleteOperation eID,count ]Wv\$JXI  
            count=count-1 ~Cj+6CrT  
        End If <6n(a)L1  
        count=count+1 } "y{d@  
    Wend s bW`  
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    'Set new z-shift +5)
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    op.Type = "ShiftZ" 59T:{d;~  
    op.val1 = tlens t_@%4Wn!1L  
    op.parent = parID  D
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    AddOperation eID, op
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    Print "Set lens thickness = " & tlens >48zRi\N  
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    '************************************************************************* |'=R`@w~0  
    'Lens index of refraction -@L*i|A  
    '************************************************************************* HHoh//(\  
    eID = FindMaterial( "Lens" ) R[Kyq|UyVr  
    GetModelMaterial eID, mat b\VY)=U  
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    mat.Nd = nlens 1"~@UcJ  
    SetModelMaterial eID, mat MF]s(7U4`  
    Print "Set lens index of refraction = " & nlens q
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    '************************************************************************* V!3O 1  
    'Pupil diameter kY4riZnm  
    '************************************************************************* }3^t,>I=,6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) aLuxCobV  
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    'Adjust pupil diameter (trimming volume inner hole) !>;p^^e  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" R^fVwDl\  
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    ' Adjust pupil location to just in front of the lens WQ=C5^u  
    parID = FindFullName( "Geometry.Arizona Eye" ) SH5GW3\h  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 6#.z:_  
    count = 0 F ~ /{1Q*  
    While GetOperationCount(eID)>count m/%sBw\rx  
        GetOperation eID, count, op O^4:4tRpt  
        If op.Type="ShiftZ" Then SAc}5.  
            DeleteOperation eID,count 4 K{4=uU  
            count=count-1 B]InOlc47  
        End If p^7ZFUP  
        count=count+1 US0)^TKrj  
    Wend vXRfsv y  
    op.Type = "ShiftZ" UFm E`|le  
    op.val1 = taq-0.01 44mYs`]  
    op.parent = parID VL&E2^*E  
    AddOperation eID, op "+r8izB  
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    Print "Set pupil diameter = " & pupilDiam N6EH  
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    'Update AZ Eye subassembly Description I%b, H`  
    eID = FindFullName( "Geometry.Arizona Eye" ) ZVVK:dDgt  
    GetEntity eID, entity C B=H1+  
    entity.Description = "Accommodation = " & A & "D" 'X"@C;q  
    SetEntity eID, entity 9]Uvy|  
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    Update *pyi;  
    Print "DONE!" )#9/vIQ  
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End Sub 2YdMsu~  
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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： h$G&4_O  
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Accommodation = 4 Diopters 2W~,,$ G  
Pupil Diameter = 4 mm x'+lNlv  
Set aqueous humor thickness = 2.81 h~urZXD<  
Set anterior lens radius = 10.4 and conic constant = -2.375869 7y&Fb  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 
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Set lens thickness = 3.927 O (<Wn-  
Set lens index of refraction = 1.42672 uw&GXOzew9  
Set pupil diameter = 4 j^"Z^TEBT  
DONE! IO/2iSbW  
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