[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 IRlN++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。 J"/
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模型 17WNJ  
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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。 I~d#p ]>  
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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. #S@UTJa  
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光源 _L?v6MTj  
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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。 'q{PtYr  
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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。 ATKYjhc _  
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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。 @o}1n?w  
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视网膜的散射 ]NaMZ  
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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。 &/B2)l6a  
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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。 pieU|?fQ  
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脚本 _Vdb?  
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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： h]J&A  
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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。 ;4-pupK~%  
余下的脚本计算与屈光度有关的所有参数。 xZ9}8*Q&:  
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分析 3bg4#c  
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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。 %nDPM? aO  
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脚本代码 +E q~X=x  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. e'/  
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Dim entity As T_ENTITY ?l\gh
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Dim op As T_OPERATION p:[`%<j0  
Dim mat As T_MODELMATERIAL `5k6s,  
Dim A As Double in=k:j,U0  
Dim pupilDiam As Double wZ]BY;  
Dim eID As Long dbMu6Bm\G  
Dim parID As Long \pewbu5^  
Dim count As Integer Kh:#S|
  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double )F%wwc^r  
Dim tlens As Double, nlens As Double e~t}z_>F  
Dim curv As Double, conic As Double RKoP6LGw  
Dim ok As Long @Q$/eL  
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Sub Main 7+D'W7Yx  
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    '用户输入对话框 PBAz`y2  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 q5I4'6NF  
        TextBox 220,21,40,21,.TextBox1 'default: 0 +]S;U&vQ  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 r_g\_y7ua  
        OKButton 40,91,90,21 WB=<W#?w7%  
        CancelButton 190,91,90,21 w371.84
 
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Y&05 *
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        TextBox 220,49,40,21,.TextBox2 'default: 4 PFDWC3<  
    End Dialog +}(B856+  
    Dim dlg As UserDialog WfTdD.Xx  
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    ok = Dialog (dlg) LKqog%,c  
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    If ok=0 Then    'cancel button was pressed (!>g8=`"  
        Print "Execution cancelled." >Rki[SNb-b  
        End -EkDG]my  
    End If G%p!os\>  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ZTBFV/{  
    If dlg.TextBox1 = "" Then VI|DMx   
        A = 0           'Default accommodation Z;~E+dXC  
    Else $MJDB  
        A = CDbl(dlg.TextBox1) k,NU,^ &  
    End If .f92^lu9  
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    If dlg.TextBox2 = "" Then l LD)i J1  
        pupilDiam = 4   'Default pupil diameter 6B;_uIq5  
    Else HyX4ob[X  
        pupilDiam = CDbl(dlg.TextBox2) b1,T!xL  
    End If ;DgX"Uzm  
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    Print " " 2W:?#h3  
    Print "Accommodation = " & A & " Diopters" iJaNP%N  
    Print "Pupil Diameter = " & pupilDiam & " mm" U9p.Dh~)vG  
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    ' Calculate new parameters with accommodation zju
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 4\'81"ei  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens >yT@?!/Q>'  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens #2vG_B<M)  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ie)1h  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens gK#fuQ$hH  
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    tlens = 3.767 + 0.04*A                  'Lens thickness /'=^^%&:B  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction GoVPo'  
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    'Adjust parameters to account for accommodation <QW1fE  
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    '************************************************************************* u-M$45vct  
    'Aqueous thickness (Position of Lens) : )"jh`  
    '************************************************************************* |e;z"-3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) % m5^p  
    GetCustomElement eID, entity C\>Mt  
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    parID = FindFullName( "Geometry.Arizona Eye" ) iXS-EB/  
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    ' Delete any shift(s) in z XoQk'7"f  
    count = 0 #~-&&S4a.J  
    While GetOperationCount(eID)>count |afK
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        GetOperation eID, count, op /z?7ic0  
        If op.Type="ShiftZ" Then Jas|P}{=fT  
            DeleteOperation eID,count OQ&D?2r  
            count=count-1 ${6'  
        End If svRaU7<UDN  
        count=count+1 #|1QA3KzO  
    Wend &
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    'Set new shift in Qbpl$L  
    op.Type = "ShiftZ" vA-p}]%  
    op.val1 = taq ^JVP2L>o*  
    op.parent = parID *vE C,)  
    AddOperation eID, op Vg~ kpgB
 
    Print "Set aqueous humor thickness = " & taq-0.55 j/mp.'P1k  
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    '************************************************************************* O36r ,/X  
    'Radius and conic constant of anterior lens {u6fa>R&$  
    '************************************************************************* $#W6z:  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) NWN)b&}  
    GetConic eID, entity, curv, conic w$:)wyR-  
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    SetConic eID, entity, 1/Rant, CCant ?JTyNg4<  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant }lpm Hvs  
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    '************************************************************************* <FT\
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    'Radius and conic constant of posterior lens |aJ6363f.  
    '************************************************************************* 2]*~1d  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ;rAW3  
    GetConic eID, entity, curv, conic z9O/MHT[w  
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    SetConic eID, entity, 1/Rpost, CCpost A"VXs1>_^  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ; 2-kQK9  
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    '************************************************************************* bXLa~r4\  
    'Lens thickness (Position of posterior lens surface) 'X<uG x  
    '************************************************************************* (k.7q~:  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *sVxjZvV  
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    ' Delete any z-shift(s) Dy@NgHe  
    count = 0 o?+e_n=  
    While GetOperationCount(eID)>count Lb 4!N`l  
        GetOperation eID, count, op *3Z#r  
        If op.Type="ShiftZ" Then {_}"USS  
            DeleteOperation eID,count %'O(Y{$Y.  
            count=count-1 ~J:lCu  
        End If (9|K}IM:  
        count=count+1 zZiVBUmE<  
    Wend 2F7R,rr  
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    'Set new z-shift )\G#[Pc7  
    op.Type = "ShiftZ" -bfd><bs  
    op.val1 = tlens T/5UlW|\  
    op.parent = parID epm|pA*  
    AddOperation eID, op !iqz 4E  
    Print "Set lens thickness = " & tlens Fj4:_(%nG  
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    '************************************************************************* ZVU)@[s  
    'Lens index of refraction
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    '************************************************************************* XWV~6"  
    eID = FindMaterial( "Lens" ) 8/v_uEG  
    GetModelMaterial eID, mat 4+:u2&I  
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    mat.Nd = nlens )\^OI:E  
    SetModelMaterial eID, mat u}_q'=<\  
    Print "Set lens index of refraction = " & nlens Jo]g{GX[  
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    '************************************************************************* `h#JDcT;a  
    'Pupil diameter _qfdk@@g  
    '************************************************************************* &#.&xc2sRZ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) (?(ahtT4T  
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    'Adjust pupil diameter (trimming volume inner hole) FMiY
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ~ nIZg5  
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    ' Adjust pupil location to just in front of the lens ]up:pddIh  
    parID = FindFullName( "Geometry.Arizona Eye" ) 3:RZ@~u=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Z1zC@z4sUj  
    count = 0 3[$VW+YV  
    While GetOperationCount(eID)>count <JlKtR&nSo  
        GetOperation eID, count, op -J:vYhq|g  
        If op.Type="ShiftZ" Then y g7z?AZ  
            DeleteOperation eID,count &fWZ%C7|jC  
            count=count-1 rB\UNXy  
        End If
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        count=count+1 Vs(;al'  
    Wend tfsG P]9$  
    op.Type = "ShiftZ" [69aTl>/  
    op.val1 = taq-0.01 G{:L^2>  
    op.parent = parID OTzh=Z^r  
    AddOperation eID, op [}Nfs3IlBw  
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    Print "Set pupil diameter = " & pupilDiam ='f>p+*c%  
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    'Update AZ Eye subassembly Description RNPqW,B!0  
    eID = FindFullName( "Geometry.Arizona Eye" ) N$.''D?7D  
    GetEntity eID, entity =,sMOJc>  
    entity.Description = "Accommodation = " & A & "D" Pai{?<zGi  
    SetEntity eID, entity TJCoID7a8  
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    Update c=7L)w:I  
    Print "DONE!" U*zjEY:A  
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End Sub <K)^MLgN  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： mI l_ [  
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Accommodation = 4 Diopters sLCL\dWT  
Pupil Diameter = 4 mm DS^PHk39  
Set aqueous humor thickness = 2.81 K2!KMhvQ  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Rj-<tR{  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 7D4P=$UJp  
Set lens thickness = 3.927 ($]y*|Obn  
Set lens index of refraction = 1.42672 2@=
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Set pupil diameter = 4 NoV2<m$  
DONE! IGVNX2
 
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