[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 8\B]!  
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。 m)Sdogt_  
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模型 =dDr:Y<@*  
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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。 6&s" "J)3  
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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. QP:|D_k  
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光源 %E*Q0/  
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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。 Ge+T[  
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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。 <tT.m[qg  
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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。 + [~)a4#  
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视网膜的散射 Df5!z\dx  
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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<c&;*  
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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。 B!1Bg9D  
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脚本 P"%f8C~r  
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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： J>8kJCh9g  
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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。 _"[Ls?tRX  
余下的脚本计算与屈光度有关的所有参数。 $Ts;o  
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分析 i"d&U7Q  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 #\Zr$?t|V  
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脚本代码 6u>]-K5  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Y.kgJ #2  
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Dim entity As T_ENTITY Zm*qV!  
Dim op As T_OPERATION V{UY_ e8W  
Dim mat As T_MODELMATERIAL 'P)c'uqd#  
Dim A As Double pp@O6  
Dim pupilDiam As Double ksf6O$  
Dim eID As Long `j8pgnY>5~  
Dim parID As Long Ey=ymf.}  
Dim count As Integer IG&twJR  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q^bYx (r5w  
Dim tlens As Double, nlens As Double -2'1KAk-W  
Dim curv As Double, conic As Double iDWM-Ytx  
Dim ok As Long $plqk^P  
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Sub Main ow{J;vFy\  
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    '用户输入对话框 2Z>8ROv^X  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 _L+j6N.h1  
        TextBox 220,21,40,21,.TextBox1 'default: 0 zx5#eMD  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 (67byO{  
        OKButton 40,91,90,21 X;n09 L`CB  
        CancelButton 190,91,90,21 +)LCYDRV7  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 09qfnQG  
        TextBox 220,49,40,21,.TextBox2 'default: 4 BA[ uO3\4  
    End Dialog &\%\"Zh  
    Dim dlg As UserDialog IhR
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    ok = Dialog (dlg) )-0+O=v  
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    If ok=0 Then    'cancel button was pressed udXzsY9Ng  
        Print "Execution cancelled." '{-Ic?F<P  
        End <4n"LJ9  
    End If zz!jt A  
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    'Assign accommodation and pupil diameter & use defaults if field left empty QQHQ3\  
    If dlg.TextBox1 = "" Then 5|cRHM#  
        A = 0           'Default accommodation _xmQGX!|  
    Else sY4q$Fq  
        A = CDbl(dlg.TextBox1) N<ux4tz  
    End If ?GlXxx=eV  
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    If dlg.TextBox2 = "" Then Xmi~fie  
        pupilDiam = 4   'Default pupil diameter Zl>dB
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    Else Npi)R)  
        pupilDiam = CDbl(dlg.TextBox2)
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    End If 3-&~jm~"  
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    Print " " RL$%Vy0  
    Print "Accommodation = " & A & " Diopters" D(OJr5Gg  
    Print "Pupil Diameter = " & pupilDiam & " mm" ~>N63I6  
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    ' Calculate new parameters with accommodation ,`02fMOLc  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness +xvn n  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 3H0B+F2XQ  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens no W]E}nN  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens QM* T?PR  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens "}wO<O6[  
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    tlens = 3.767 + 0.04*A                  'Lens thickness M9""(`U  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction CmV &+C$V%  
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    'Adjust parameters to account for accommodation ]Vmo>  
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    '************************************************************************* &q@brX<,=  
    'Aqueous thickness (Position of Lens) k}p8"'O  
    '************************************************************************* IxS%V31  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) H%XF~tF:  
    GetCustomElement eID, entity Fe4>G8uuwn  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Ix}6%2\  
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    ' Delete any shift(s) in z N'WC!K.e
 
    count = 0 vg5_@7  
    While GetOperationCount(eID)>count RgA"`p7{  
        GetOperation eID, count, op [61*/=gWe  
        If op.Type="ShiftZ" Then "TJ*mN.i{}  
            DeleteOperation eID,count g&85L$   
            count=count-1 ~D>pu%F  
        End If bc4V&  
        count=count+1 KbtV>  
    Wend W7 dSx  
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    'Set new shift in D[#V  
    op.Type = "ShiftZ" M:{Aq&.  
    op.val1 = taq ];4!0\M
 
    op.parent = parID |oke)w=gn  
    AddOperation eID, op as!a!1  
    Print "Set aqueous humor thickness = " & taq-0.55 w3ni@'X8  
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    '************************************************************************* BkGExz  
    'Radius and conic constant of anterior lens pm,xGo2  
    '************************************************************************* #MlpOk*G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) P3
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    GetConic eID, entity, curv, conic y:}qoT_.  
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    SetConic eID, entity, 1/Rant, CCant (Jw_2pHxr"  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant |:&6eDlR  
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    '************************************************************************* j&oRj6;Ha+  
    'Radius and conic constant of posterior lens 4minzrKM\  
    '************************************************************************* Xs2 jR14`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 0Zi+x#&d  
    GetConic eID, entity, curv, conic T"W<l4i-  
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    SetConic eID, entity, 1/Rpost, CCpost 1QG q;6\  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 5C9b*]-#  
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    '************************************************************************* kuy?n-1g  
    'Lens thickness (Position of posterior lens surface) B(++*#T!^m  
    '************************************************************************* ZQ_6I}i")  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) L|T?,^  
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    ' Delete any z-shift(s) p8_^6wfg  
    count = 0
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    While GetOperationCount(eID)>count z6C(?R  
        GetOperation eID, count, op =+Fb\HvX{  
        If op.Type="ShiftZ" Then o+A1-&qhN  
            DeleteOperation eID,count kFWwz^x  
            count=count-1 $TXxhd 6  
        End If #BUq;5  
        count=count+1
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    Wend 0X5cn 0L^  
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    'Set new z-shift b4
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    op.Type = "ShiftZ" ^w\22 Q  
    op.val1 = tlens bGH#s {'5  
    op.parent = parID wW@e#:  
    AddOperation eID, op UxTLr-db^  
    Print "Set lens thickness = " & tlens 7@fS2mu  
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    '************************************************************************* BB/wL_=:  
    'Lens index of refraction 1@}F8&EZ  
    '************************************************************************* hpF_@n  
    eID = FindMaterial( "Lens" ) h#
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    GetModelMaterial eID, mat T+}|$/Tv  
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    mat.Nd = nlens WMf / S"=  
    SetModelMaterial eID, mat S} m=|3%y  
    Print "Set lens index of refraction = " & nlens tb+gCs'D  
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    '************************************************************************* #:gd9os :  
    'Pupil diameter DWt|lO  
    '************************************************************************* ltNCti{Q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) JX=rL6Y@:;  
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    'Adjust pupil diameter (trimming volume inner hole) .n]"vpWm[  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" V/ G1C^'/  
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    ' Adjust pupil location to just in front of the lens sN[}B{+  
    parID = FindFullName( "Geometry.Arizona Eye" ) i<^
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) u?Ffqt9'  
    count = 0 c| ^I}  
    While GetOperationCount(eID)>count o72r `2  
        GetOperation eID, count, op %Rc#/y  
        If op.Type="ShiftZ" Then F}_b7|^  
            DeleteOperation eID,count o8g7wM]M  
            count=count-1 \Ggh 95y  
        End If jq,M1  
        count=count+1 %} ``:  
    Wend I@cw=_EQL  
    op.Type = "ShiftZ" !/XNpQP  
    op.val1 = taq-0.01 w.?4}'DK  
    op.parent = parID } {1IB  
    AddOperation eID, op PEf yHf7`  
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    Print "Set pupil diameter = " & pupilDiam M}\h?s   
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    'Update AZ Eye subassembly Description F06o-xH=  
    eID = FindFullName( "Geometry.Arizona Eye" ) d+q],\"R  
    GetEntity eID, entity
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    entity.Description = "Accommodation = " & A & "D" +F8{4^w1  
    SetEntity eID, entity oP`l)
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    Update Tx;a2:6\[  
    Print "DONE!" b)d;eS  
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End Sub E!9WZY  
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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： -l= 4{^pK  
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Accommodation = 4 Diopters fqgp{(`@>  
Pupil Diameter = 4 mm M
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Set aqueous humor thickness = 2.81 >WSh)(Cg  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ;qWu8\T+  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ~[ufL25K  
Set lens thickness = 3.927 |R}=HsYey  
Set lens index of refraction = 1.42672 cpdESc9W  
Set pupil diameter = 4 pm6#azQ  
DONE! Tv=lr6t8  
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