[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ?8HHA:GP  
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。 du+y5dw  
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模型 :WC2Ax7$2  
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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。 8][nm
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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. PxF<\pu&  
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光源 eeIhed9  

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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。 \Fl+\?~D  
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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。 +nUy,S?43  
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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。 oV)~@0B&0  
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视网膜的散射 U0=]  
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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。 r/& sub"X  
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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。 33jovK2  
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脚本 I[b}4M6E  
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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： ?P
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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。 Fd?"-  
余下的脚本计算与屈光度有关的所有参数。 b k|m4|  
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分析 kR]!Vr*yh  
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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。 6)z?f4,  
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脚本代码 $f,n8]  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. :*t"8;O[  
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Dim entity As T_ENTITY QF-LU  
Dim op As T_OPERATION 1?)Xp|O  
Dim mat As T_MODELMATERIAL RbCPmiZcH  
Dim A As Double |UP `B|  
Dim pupilDiam As Double H(2!1?N+  
Dim eID As Long |_}2f  
Dim parID As Long Kh(ZU^{n  
Dim count As Integer D,;\o7V  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double !E,A7s  
Dim tlens As Double, nlens As Double e2z h&j  
Dim curv As Double, conic As Double 9m|
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Dim ok As Long PGYXhwOI  
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Sub Main m~@;~7Ix  
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    '用户输入对话框 ?9! Z<H  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1
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        TextBox 220,21,40,21,.TextBox1 'default: 0 53c0 E  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 3l[McZ  
        OKButton 40,91,90,21 4Y,R-+f
 
        CancelButton 190,91,90,21 3 N7[.I>A  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 0`)iIz  
        TextBox 220,49,40,21,.TextBox2 'default: 4 so)"4 SEu  
    End Dialog I&MY{f  
    Dim dlg As UserDialog U7doU'V/  
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    ok = Dialog (dlg) ^Y u6w\QM
 
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    If ok=0 Then    'cancel button was pressed BYTnrPA&Z;  
        Print "Execution cancelled." #Y0-BYa^  
        End rEHkw '  
    End If fbWFLSm;  
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    'Assign accommodation and pupil diameter & use defaults if field left empty fGw^:
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    If dlg.TextBox1 = "" Then s <   
        A = 0           'Default accommodation +j(d| L\  
    Else CPVjmRUF|  
        A = CDbl(dlg.TextBox1) P~s$EJL*  
    End If  %ObLWH'  
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    If dlg.TextBox2 = "" Then nL$x|}XAcj  
        pupilDiam = 4   'Default pupil diameter o@#Y8M  
    Else 4(Ov1a>  
        pupilDiam = CDbl(dlg.TextBox2) K TsgJ\W  
    End If 0dA7pY9  
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    Print " " rj6tZJZ#o0  
    Print "Accommodation = " & A & " Diopters" mNb ?*3\  
    Print "Pupil Diameter = " & pupilDiam & " mm" CT KG9 T  
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    ' Calculate new parameters with accommodation JYrY
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness L
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens hq:&wN7Q  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ZunCKc  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens L7= Q<D<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens !).}u,*'no  
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    tlens = 3.767 + 0.04*A                  'Lens thickness -b9;5eS!  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 1iX)d)
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    'Adjust parameters to account for accommodation ?gO8kPg/D  
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    '************************************************************************* Py>{t4;S  
    'Aqueous thickness (Position of Lens) 3I!?e!y3(  
    '************************************************************************* b+6"#/s  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) %'x
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    GetCustomElement eID, entity a@@M+9Q  
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    parID = FindFullName( "Geometry.Arizona Eye" ) "]m+z)lWd  
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    ' Delete any shift(s) in z 4-kZJ\]  
    count = 0 Q.9qImgN  
    While GetOperationCount(eID)>count /^$UhX9v  
        GetOperation eID, count, op BnCKSg7V  
        If op.Type="ShiftZ" Then R64!>o"nED  
            DeleteOperation eID,count Ul_M3"Z  
            count=count-1
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        End If /wxE1][.  
        count=count+1 h'i{&mS_b  
    Wend Ja]?&j  
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    'Set new shift in CvPioi  
    op.Type = "ShiftZ" qC_mu)6  
    op.val1 = taq }m/RZP~=  
    op.parent = parID ^9_UUzf\  
    AddOperation eID, op RQkyCAGx  
    Print "Set aqueous humor thickness = " & taq-0.55 8K;Y2 #
 
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    '************************************************************************* d'*]ns  
    'Radius and conic constant of anterior lens lJzl6&  
    '************************************************************************* X53mzs  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) :^'O}2NP  
    GetConic eID, entity, curv, conic ewuXpv%vwW  
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    SetConic eID, entity, 1/Rant, CCant )i>[M"7  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Q \]Xm>  
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    '************************************************************************* 2oZ9laJO  
    'Radius and conic constant of posterior lens e8h,,:l3j  
    '************************************************************************* T"T;`y@(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) nRb^<cZf  
    GetConic eID, entity, curv, conic Sf/q2/r?6[  
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    SetConic eID, entity, 1/Rpost, CCpost HPQ/~0$  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost kvGCbRC  
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    '************************************************************************* Fl{WAg  
    'Lens thickness (Position of posterior lens surface) D-IR!js ]  
    '************************************************************************* mPPk)qy  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) T;\^#1  
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    ' Delete any z-shift(s) V8-h%|$p3W  
    count = 0
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    While GetOperationCount(eID)>count F?u^"}%Fc  
        GetOperation eID, count, op 02JoA+  
        If op.Type="ShiftZ" Then t` 8!AhOgc  
            DeleteOperation eID,count W3&tJ8*3  
            count=count-1 I\Glc=T*  
        End If )9=(|Lp  
        count=count+1 "R9Yb,tIN  
    Wend /}5B&TZ=(3  
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    'Set new z-shift i3mAfDF  
    op.Type = "ShiftZ" yg;_.4TpIO  
    op.val1 = tlens Y\+KoR';  
    op.parent = parID R4e&^tI@*  
    AddOperation eID, op PoShQR<  
    Print "Set lens thickness = " & tlens =
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    '************************************************************************* w7-
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    'Lens index of refraction Y7U&Q:5'  
    '************************************************************************* jU=<
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    eID = FindMaterial( "Lens" ) wk\L*\@Y}  
    GetModelMaterial eID, mat },+~F8B  
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    mat.Nd = nlens LD(C\  
    SetModelMaterial eID, mat Vf-5&S&9  
    Print "Set lens index of refraction = " & nlens 0O2n/`'  
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    '************************************************************************* y/_wx(2  
    'Pupil diameter S{p}ux[}=  
    '************************************************************************* noNm^hFL  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) `_ (~ Ud  
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    'Adjust pupil diameter (trimming volume inner hole) :WXf.+IA  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" FN )d1q(~  
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    ' Adjust pupil location to just in front of the lens _$/ +D:K  
    parID = FindFullName( "Geometry.Arizona Eye" ) noA-
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) _MYx%Z  
    count = 0 *
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    While GetOperationCount(eID)>count ~!+h?[miV  
        GetOperation eID, count, op b;9
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        If op.Type="ShiftZ" Then i(HByI  
            DeleteOperation eID,count m/USC'U%  
            count=count-1 -!*p*3|03|  
        End If K%{ad1$c  
        count=count+1 0^_MN~s(X  
    Wend ;G
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    op.Type = "ShiftZ" w;yx<1f  
    op.val1 = taq-0.01 ]1fZupM^6  
    op.parent = parID EIX\O6*  
    AddOperation eID, op f =_^>>.  
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    Print "Set pupil diameter = " & pupilDiam q#1X[A()  
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    'Update AZ Eye subassembly Description & 5 <**  
    eID = FindFullName( "Geometry.Arizona Eye" ) %"7WXOv&z  
    GetEntity eID, entity gM_:l  
    entity.Description = "Accommodation = " & A & "D" IUhp;iH  
    SetEntity eID, entity *Wyl2op6  
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    Update 6$B'Q30}r  
    Print "DONE!" ~8Sqa%F>  
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End Sub [V< 1_zqt  
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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： d7i#w #  
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Accommodation = 4 Diopters f4]&pcK  
Pupil Diameter = 4 mm {'(ej5,6  
Set aqueous humor thickness = 2.81 =jIxI,  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ~PUsgL^  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 oMTY)`me  
Set lens thickness = 3.927 }|He?[TR  
Set lens index of refraction = 1.42672 9H$g?';  
Set pupil diameter = 4 E*4t8  
DONE! u[`v&e  
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