[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 +r8:t5:/I  
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。 haTmfh_|  
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模型 8rZJvE#c  
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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。 jTSN`R9@  
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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. .5?e)o)  
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光源
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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。 #Jx6DQGa  
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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。 d1[;~)  
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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。 ab-z 7g  
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视网膜的散射 I-glf?F)  
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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。 ]?un'$%e  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 `<#Ufi*c  
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脚本 H6.  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： E[=#Rw!*  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 <(E9U.  
余下的脚本计算与屈光度有关的所有参数。 QAxR'.d  
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分析 &Hj1jM'  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 0Yo(pW,k  
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脚本代码 p=T6Ix'_2e  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. e~1$x`DH  
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Dim entity As T_ENTITY 1nZ7xCDK98  
Dim op As T_OPERATION 9Od|R"aS|  
Dim mat As T_MODELMATERIAL Q2LAXTF]y  
Dim A As Double IxU#x*  
Dim pupilDiam As Double p!o+8Xz5  
Dim eID As Long C"cBlru8B  
Dim parID As Long
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Dim count As Integer e_h`x+\:  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /R
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Dim tlens As Double, nlens As Double lxh}N,  
Dim curv As Double, conic As Double .t9*wz  
Dim ok As Long [ApAd  
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Sub Main %7SGQE#W_~  
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    '用户输入对话框 d-ML[^G  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 aSMSuX8  
        TextBox 220,21,40,21,.TextBox1 'default: 0 bBp('oEJ
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ,AuejMd  
        OKButton 40,91,90,21  B@K =^77  
        CancelButton 190,91,90,21 JfVGs;_,  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 _OY<Hb3%M  
        TextBox 220,49,40,21,.TextBox2 'default: 4 s g
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    End Dialog 7: .bqRu  
    Dim dlg As UserDialog d$<1Ma}  
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    ok = Dialog (dlg) JrJTIUf_  
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    If ok=0 Then    'cancel button was pressed p}MH LM  
        Print "Execution cancelled." #(dERET*  
        End I`
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    End If G&,2>qxKR  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ;_D5]kl`  
    If dlg.TextBox1 = "" Then 12S[m~L%  
        A = 0           'Default accommodation e=4k|8G  
    Else wg{Y6XyH  
        A = CDbl(dlg.TextBox1) 9 :FzSD   
    End If =G-u "QJ6  
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    If dlg.TextBox2 = "" Then qp`G5bw  
        pupilDiam = 4   'Default pupil diameter -) \!@n0  
    Else aj6{  
        pupilDiam = CDbl(dlg.TextBox2) hZDv5]V:0  
    End If TM$Ek^fQ.  
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    Print " " }ej-Lu,b3  
    Print "Accommodation = " & A & " Diopters" DOGg=`XK1  
    Print "Pupil Diameter = " & pupilDiam & " mm" #7dM %  
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    ' Calculate new parameters with accommodation ealh>Y  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness RWK##VHK  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens hP]zC1s  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens @V5'+^O  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens }hX"A!0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9KLhAYaq  
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    tlens = 3.767 + 0.04*A                  'Lens thickness aShZdeC*f  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ICI8xP}a?  
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    'Adjust parameters to account for accommodation MB]Y|Vee  
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    '************************************************************************* 4,g3 c  
    'Aqueous thickness (Position of Lens) d8T,33>T  
    '************************************************************************* /DQcM.3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 2\1\Jn#q  
    GetCustomElement eID, entity QWWoj[d#  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 4uUR2J  
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    ' Delete any shift(s) in z gDJ@s   
    count = 0 ,9;d"ce  
    While GetOperationCount(eID)>count Q`X5W  
        GetOperation eID, count, op |;B 'C#  
        If op.Type="ShiftZ" Then tHo0q<.oX  
            DeleteOperation eID,count B(%bBhs  
            count=count-1 D7Nz3.j  
        End If Pf]O'G&F  
        count=count+1 \w=7L-
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    Wend > AV R3b  
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    'Set new shift in L5*,l`lET  
    op.Type = "ShiftZ" 6@HY+RC
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    op.val1 = taq 4)3!n*I  
    op.parent = parID ^D0BGC&&  
    AddOperation eID, op NR)[,b\v  
    Print "Set aqueous humor thickness = " & taq-0.55 :4D#hOI  
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    '************************************************************************* YMx zj  
    'Radius and conic constant of anterior lens dsxaxbVj%  
    '************************************************************************* C4P7,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) \..(!>,%F  
    GetConic eID, entity, curv, conic s=nE'/q1|  
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    SetConic eID, entity, 1/Rant, CCant T7.u7@V2  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant +C)auzY7N  
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    '************************************************************************* B&m?3w  
    'Radius and conic constant of posterior lens OQA3~\Vu  
    '************************************************************************* BVC{Zq6hi  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) VrokEK*qbY  
    GetConic eID, entity, curv, conic oLn| UWe_  
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    SetConic eID, entity, 1/Rpost, CCpost u[jdYWQa  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost <>JDA(F"  
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    '************************************************************************* Ffm Q$>S  
    'Lens thickness (Position of posterior lens surface) ytmlG%  
    '************************************************************************* >~$ S!  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Iq\sf-1E  
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    ' Delete any z-shift(s) 00G[`a5  
    count = 0 r`cCHZo/V  
    While GetOperationCount(eID)>count V]PTAhc  
        GetOperation eID, count, op +WwQ!vWWd  
        If op.Type="ShiftZ" Then Te>7I  
            DeleteOperation eID,count kx1-.~)p(z  
            count=count-1 w'5~GhnP+  
        End If jq["z<V)x  
        count=count+1 l{Hi5x'H  
    Wend U&Ay3/  
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    'Set new z-shift Vb 4Qt#o  
    op.Type = "ShiftZ" `>8|  
    op.val1 = tlens ?k_=?m  
    op.parent = parID -lMC{~h\(S  
    AddOperation eID, op 5H 1(C#|  
    Print "Set lens thickness = " & tlens ~9oS~fP?I  
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    '************************************************************************* eOn,`B1  
    'Lens index of refraction (p
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    '************************************************************************* %e%nsj6  
    eID = FindMaterial( "Lens" ) o D* '  
    GetModelMaterial eID, mat 6XQ)Q)  
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    mat.Nd = nlens \hM6 ykY-  
    SetModelMaterial eID, mat jd2Fh):q  
    Print "Set lens index of refraction = " & nlens V6$v@Zq  
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    '************************************************************************* u>S&?X'a  
    'Pupil diameter lGLZIp  
    '************************************************************************* iMp)g%Ng  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) \Y!Z3CK  
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    'Adjust pupil diameter (trimming volume inner hole) x2ol  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Op%^dwVG(v  
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    ' Adjust pupil location to just in front of the lens F'j:\F6C;  
    parID = FindFullName( "Geometry.Arizona Eye" ) K.z}%a  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e-}PJ%!,T  
    count = 0 \R-u+ci$ZY  
    While GetOperationCount(eID)>count 7OWiG,  
        GetOperation eID, count, op ,XA;S5FE  
        If op.Type="ShiftZ" Then 0KDDAkR5R  
            DeleteOperation eID,count n1ED _9  
            count=count-1 2s{yg%U(  
        End If y ph  
        count=count+1 5e2mEQU>  
    Wend `z=MI66Nl  
    op.Type = "ShiftZ" D9LwYftZ  
    op.val1 = taq-0.01 XPEjMm'*b3  
    op.parent = parID iuHG9#n  
    AddOperation eID, op <aHK{*'3  
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    Print "Set pupil diameter = " & pupilDiam mtOrb9`m  
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    'Update AZ Eye subassembly Description ,Xh4(Gn#b  
    eID = FindFullName( "Geometry.Arizona Eye" ) _+;x4K;  
    GetEntity eID, entity _>`0!mG  
    entity.Description = "Accommodation = " & A & "D" ./g0T{&  
    SetEntity eID, entity GS{9MGl  
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    Update W"Rii]GK"  
    Print "DONE!" e+6~JbMV  
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End Sub {[9^@k  
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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： V+Tj[:ok  
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Accommodation = 4 Diopters ~clWG-i  
Pupil Diameter = 4 mm ~T-.k 7t  
Set aqueous humor thickness = 2.81 T5Fah#-4  
Set anterior lens radius = 10.4 and conic constant = -2.375869 xxiLi46/  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Ml3F\ fAW  
Set lens thickness = 3.927 53T2w,?  
Set lens index of refraction = 1.42672 E+2y-B)E  
Set pupil diameter = 4 GS,pl9#V_  
DONE! .6"7Xxe]<  
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