[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 f1_<G  
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。 $W9{P;  
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模型 ,
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 H+ 0$tHi  
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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. U
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光源 >ey\jDr#O  
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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。 I9mvte  
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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。 IS#FiH  
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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。 bV$)!]V  
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视网膜的散射 L?Qg#YSd~  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 w[!^;#  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 00SbH$SU  
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脚本 C_n9T{k  
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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： t0nI('LX,  
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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。 _jNj-)RB_  
余下的脚本计算与屈光度有关的所有参数。 q*7zx_ o  
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分析 }p!HT6 tZ  
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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。 F^5?\  
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脚本代码 HE'2"t[a  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Xy@7y[s]  
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Dim entity As T_ENTITY mFSw@CC  
Dim op As T_OPERATION Yb/i{@AJ  
Dim mat As T_MODELMATERIAL GHsilba  
Dim A As Double t: IN,Kl4  
Dim pupilDiam As Double l"!Ko G7  
Dim eID As Long )@L'wW  
Dim parID As Long <IC~GqXv  
Dim count As Integer A
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 59!Fkd3  
Dim tlens As Double, nlens As Double .h& .K  
Dim curv As Double, conic As Double t\ 7~S&z  
Dim ok As Long aS pWsT  
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Sub Main |6(ZD^w  
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    '用户输入对话框 m<w"T7  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 &CIVL#];e  
        TextBox 220,21,40,21,.TextBox1 'default: 0 TP"1\O  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 L}FOjrN  
        OKButton 40,91,90,21 K\$J4~EtG  
        CancelButton 190,91,90,21 OzQ -7|m'J  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 13+<Q \  
        TextBox 220,49,40,21,.TextBox2 'default: 4 \N4 y<  
    End Dialog _^
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    Dim dlg As UserDialog 4lM8\Lr  
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    ok = Dialog (dlg) gCN$}  
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    If ok=0 Then    'cancel button was pressed T<L^N+<,{N  
        Print "Execution cancelled." hTEx]# (  
        End jU3Z*Z)zN  
    End If l%`F&8K  
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    'Assign accommodation and pupil diameter & use defaults if field left empty vi|R(&  
    If dlg.TextBox1 = "" Then r)1'eP
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        A = 0           'Default accommodation %uoQ9lD'  
    Else h[?O+Z^
 
        A = CDbl(dlg.TextBox1) OKP9CLg9  
    End If VL/|tL>E^  
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    If dlg.TextBox2 = "" Then gi-Yqco  
        pupilDiam = 4   'Default pupil diameter -YjA+XP  
    Else UTSL  
        pupilDiam = CDbl(dlg.TextBox2) dTL5-@  
    End If sU!6hk  
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    Print " " 9Li%KOY  
    Print "Accommodation = " & A & " Diopters" |8.(XsN  
    Print "Pupil Diameter = " & pupilDiam & " mm" DwV4o^J:l  
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    ' Calculate new parameters with accommodation cPl`2&p  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness c(/VYMJZ&  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Kv@eI$t5  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens [Cb`{  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {w8 NN-n  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 'Vr
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    tlens = 3.767 + 0.04*A                  'Lens thickness GCttXAto  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction /Ux*u#  
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    'Adjust parameters to account for accommodation ~+H"
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    '************************************************************************* t'~/$=9}  
    'Aqueous thickness (Position of Lens) N6T{  
    '************************************************************************* mrJQ#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) /{{UP-  
    GetCustomElement eID, entity jr /lk  
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    parID = FindFullName( "Geometry.Arizona Eye" ) T?p`)  
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    ' Delete any shift(s) in z e2+BWKaU  
    count = 0 W{5:'9,  
    While GetOperationCount(eID)>count bpkwn<7
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        GetOperation eID, count, op }%-t+Tf,  
        If op.Type="ShiftZ" Then ycJg%]F*5  
            DeleteOperation eID,count ai
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            count=count-1 Z Dhx5SL&  
        End If Fa epDjY8  
        count=count+1 '&FjW-`" G  
    Wend ;c
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    'Set new shift in M('d-Q{B7L  
    op.Type = "ShiftZ" 2T)sXBu  
    op.val1 = taq hAqg Iu*  
    op.parent = parID DOQc"+  
    AddOperation eID, op =l9T7az  
    Print "Set aqueous humor thickness = " & taq-0.55 1mSaS4!"B  
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    '************************************************************************* :+%Zh@u\  
    'Radius and conic constant of anterior lens $>R(W=Q  
    '************************************************************************* RkuuogZ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) UzKFf&-:;K  
    GetConic eID, entity, curv, conic M0c9pE  
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    SetConic eID, entity, 1/Rant, CCant kJ(A,s|  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant -#29xRPk  
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    '************************************************************************* ;50_0Mv;(:  
    'Radius and conic constant of posterior lens kzq29S  
    '************************************************************************* jAND7&W  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) a45ss7  
    GetConic eID, entity, curv, conic gLL\F1|0x  
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    SetConic eID, entity, 1/Rpost, CCpost ?G08NR  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost zQH]s?v  
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    '************************************************************************* 8V$3b?]  
    'Lens thickness (Position of posterior lens surface) ~SjZk|  
    '************************************************************************* plV7+?G  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) JeY'8B  
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    ' Delete any z-shift(s) }'=h4yI  
    count = 0 fMeZ]rb  
    While GetOperationCount(eID)>count -qebQv  
        GetOperation eID, count, op 4S L_-Hm.  
        If op.Type="ShiftZ" Then 137Xl>nO  
            DeleteOperation eID,count |*,jU;NI  
            count=count-1 >!9h6BoGV  
        End If Sd:.KRTu.  
        count=count+1 c[0oh.  
    Wend t]^_l$  
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    'Set new z-shift _1jw=5^P\i  
    op.Type = "ShiftZ" 8,o17}NY,  
    op.val1 = tlens MFg'YA2/  
    op.parent = parID WwW^[k (X  
    AddOperation eID, op *+8%kn`c  
    Print "Set lens thickness = " & tlens PM4>ThQ  
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    '************************************************************************* G5{Ot>;*%  
    'Lens index of refraction 2W3W/> 2h  
    '************************************************************************* y,<$X.>QO|  
    eID = FindMaterial( "Lens" ) &.*uc|{  
    GetModelMaterial eID, mat ZM~`Gd9K0E  
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    mat.Nd = nlens H/+{e,SW"  
    SetModelMaterial eID, mat  v_sm  
    Print "Set lens index of refraction = " & nlens 00M`%c/  
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    '************************************************************************* GM}C]MVD  
    'Pupil diameter n=`w9qajd  
    '************************************************************************* {r
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) n6d^>s9J  
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    'Adjust pupil diameter (trimming volume inner hole) h39e)%x1  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" p(7QAd4  
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    ' Adjust pupil location to just in front of the lens yx0Q+Sm1:  
    parID = FindFullName( "Geometry.Arizona Eye" ) rR!U;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) H4skvIl  
    count = 0 *fP(6e#G,  
    While GetOperationCount(eID)>count (^H5EeGV{  
        GetOperation eID, count, op 4uX(_5#j  
        If op.Type="ShiftZ" Then \$;~74}  
            DeleteOperation eID,count A1Q +0  
            count=count-1 IT1PPm  
        End If b~W)S/wF$P  
        count=count+1 /Dw@d,&[  
    Wend ogeRYq,g  
    op.Type = "ShiftZ" (/fT]6(  
    op.val1 = taq-0.01 +t>XxYScx  
    op.parent = parID 0VIZ=-e  
    AddOperation eID, op 79z)C35~  
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    Print "Set pupil diameter = " & pupilDiam d_iY&-gq/  
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    'Update AZ Eye subassembly Description l.7d$8'\  
    eID = FindFullName( "Geometry.Arizona Eye" ) sA\L7`2H  
    GetEntity eID, entity ] SK[C" S  
    entity.Description = "Accommodation = " & A & "D" _[1^
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    SetEntity eID, entity ycjJbL(.  
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    Update C<t RU5|  
    Print "DONE!" +=,u jO:  
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End Sub kr{)  
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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： @,YlmX}  
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Accommodation = 4 Diopters %uEtQh[  
Pupil Diameter = 4 mm !2tw,QM
  
Set aqueous humor thickness = 2.81 c `ud;lI  
Set anterior lens radius = 10.4 and conic constant = -2.375869 fqX~xp  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &9@gm--b:  
Set lens thickness = 3.927 !u%9;>T7  
Set lens index of refraction = 1.42672 a hwy_\  
Set pupil diameter = 4 &GU@8  
DONE! 7(@(Hm  
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