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    [转载]FRED运用:Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2016-02-24
    简介 A:N!H_x  
    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。 |%$d/<<PZ  
    |>VHV} 4)<  
    模型 Y~Zg^x2  
    A=BpB}b  
    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(<1-3~  
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    Table 1. AZ眼睛模型的定义
    kD2MqR>  
    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. zm"&8/l  
    /bg8oB4  
    光源 s*rtm  
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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。 =_=jXWOQv  
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    图1. 光源和提示信息使用
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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。 aRfkJPPa[  
    OG0ro(|dI  
    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。 =w,%W^"E  
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    图2. 字母F光源的设定方法光 2N`Vx3  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 k?1cxY s  
    @ -g^R4e<  
    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。 Wu%;{y~#}  
    ("wPkm^  
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    图4. 视网膜朗伯散射设定
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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。 lAV6z%MmM  
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    图5. 视网膜重点采样规格设定
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    脚本 I x-FJF-  
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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: SC"=M^E  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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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。 c7'I'~  
    余下的脚本计算与屈光度有关的所有参数。 zLC\Rc4  
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    分析 5>"-lB &  
    `fc2vaSH =  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 !dStl:B  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 -.i1l/FzP  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. IgQW 5E#  
    )# M*@e$k  
    Dim entity As T_ENTITY r68'DJ&m3  
    Dim op As T_OPERATION pX*Oc6.0mu  
    Dim mat As T_MODELMATERIAL \P+lb-~\"  
    Dim A As Double 2Cj?k.Zk  
    Dim pupilDiam As Double rW&8#&  
    Dim eID As Long `4g m'C  
    Dim parID As Long +wgNuj0=*  
    Dim count As Integer [#$z.BoEo  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double (KK9/k  
    Dim tlens As Double, nlens As Double jun>(7  
    Dim curv As Double, conic As Double QY/36gK  
    Dim ok As Long w-"o?;)a  
    wBA[L}  
    Sub Main /`Yp]l  
    U;LbP -{B  
        '用户输入对话框 K9;pX2^z9  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 v;80RjPy>  
            TextBox 220,21,40,21,.TextBox1 'default: 0 k]] (I<2  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ix=HLF-0zC  
            OKButton 40,91,90,21 1ZOHyO  
            CancelButton 190,91,90,21 9pb4!=g*  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k"LbB#Q  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ?ye) &  
        End Dialog `u 3to{  
        Dim dlg As UserDialog 6NVf&;laQ  
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        ok = Dialog (dlg) ,q]W i#  
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        If ok=0 Then    'cancel button was pressed xVao3+r  
            Print "Execution cancelled." >sv|  
            End NX4!G>v  
        End If %`t;5kmR  
    Qv,8tdx  
        'Assign accommodation and pupil diameter & use defaults if field left empty BQ2EDy=}6  
        If dlg.TextBox1 = "" Then @kK${  
            A = 0           'Default accommodation }xJ9EE*G/  
        Else rZ/,^[T  
            A = CDbl(dlg.TextBox1) )cNG)F  
        End If b*LEoQSl0V  
    S0eD 2  
        If dlg.TextBox2 = "" Then D642}VD  
            pupilDiam = 4   'Default pupil diameter 7afD^H%  
        Else qOVs9'R  
            pupilDiam = CDbl(dlg.TextBox2) Wky=]C%  
        End If ?dP3tLR  
    )sWdN(E3  
        Print " " lG;RfDI-  
        Print "Accommodation = " & A & " Diopters" % < D  
        Print "Pupil Diameter = " & pupilDiam & " mm" Fy3&Emu  
    ??5qR8n.  
        ' Calculate new parameters with accommodation .9_]8 T  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 3 [: x#r  
    >Ip>x!wi  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens PdcF  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens qRT1Wre 3  
    :[ z=u  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Gnop  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Y O;N9wu3f  
    Pf5RlpL:p  
        tlens = 3.767 + 0.04*A                  'Lens thickness |q"WJQ  
    B- =*"H?q  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +h_'hz&HlS  
    #m{K  
        'Adjust parameters to account for accommodation /~)vma1<  
    {|= 8wB  
        '************************************************************************* {Hm0Q  
        'Aqueous thickness (Position of Lens) _IBI x\F  
        '************************************************************************* ?W-J2tgss{  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) C8>zr6)1  
        GetCustomElement eID, entity ,rVm81-2  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 'yxRz5  
    H6X]D"Y,  
        ' Delete any shift(s) in z ]S4TX  
        count = 0 0 Po",\^  
        While GetOperationCount(eID)>count KSU?Tg&JR  
            GetOperation eID, count, op -f IX6  
            If op.Type="ShiftZ" Then QNj hA'[T  
                DeleteOperation eID,count ":E 7#9  
                count=count-1 ?3~]H   
            End If m,NUNd#)\  
            count=count+1 G{ ~pA4  
        Wend  5 fY\0  
    xzTTK+D@  
        'Set new shift in o?@,f/" 5  
        op.Type = "ShiftZ" V1 T?T9m  
        op.val1 = taq k0~mK7k  
        op.parent = parID ZnSDq_Uk  
        AddOperation eID, op 3on]#/"1b  
        Print "Set aqueous humor thickness = " & taq-0.55 ieXhOA  
    ]4wyuP,up  
        '************************************************************************* &^$dHr6v  
        'Radius and conic constant of anterior lens v J9Uw  
        '************************************************************************* ~&B{"d  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) N)|mA)S)  
        GetConic eID, entity, curv, conic  w=5D>]  
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        SetConic eID, entity, 1/Rant, CCant ,DsqKXSU  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant T^.;yU_B?  
    YSERQo  
        '************************************************************************* T[*1*303  
        'Radius and conic constant of posterior lens ,tJ%t#  
        '************************************************************************* mpfc2>6Il.  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) "\M16N  
        GetConic eID, entity, curv, conic bE:oF9J?  
    QSPneYD  
        SetConic eID, entity, 1/Rpost, CCpost 17g\XC@ Cl  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost I@IZ1 /J,r  
    ;1PnbU b  
        '************************************************************************* `(s&H8x#  
        'Lens thickness (Position of posterior lens surface) $GhdH)  
        '************************************************************************* d\&{Ev9v  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZYDLl8  
    nI4Kuz`dF  
        ' Delete any z-shift(s) @b[{.m U  
        count = 0 )N h67P3X"  
        While GetOperationCount(eID)>count :ad  
            GetOperation eID, count, op W FVx7  
            If op.Type="ShiftZ" Then , 6 P:S7  
                DeleteOperation eID,count (XW\4msB)I  
                count=count-1 *6D0>F  
            End If hbm%{*d  
            count=count+1 KP{|xQ>  
        Wend :{@&5KQ8)  
    x_Zi^]  
        'Set new z-shift 0G`_dMN  
        op.Type = "ShiftZ" 2@K D '^(  
        op.val1 = tlens `B6~KZ  
        op.parent = parID e~C5{XEE  
        AddOperation eID, op 9}p>='  
        Print "Set lens thickness = " & tlens n,D~ whZx  
    faQ}J%a  
        '************************************************************************* j\l9|vpp  
        'Lens index of refraction V5w00s5?%  
        '************************************************************************* K%AbM#o<  
        eID = FindMaterial( "Lens" ) YjaEKM8*  
        GetModelMaterial eID, mat [>+R|;ln  
    VN!`@Ci/  
        mat.Nd = nlens Hl`S\  
        SetModelMaterial eID, mat PwP;+R};|  
        Print "Set lens index of refraction = " & nlens K;,zE6WD$$  
    4q sIJJ[.  
        '************************************************************************* z}I=:  
        'Pupil diameter h tC~BK3(  
        '************************************************************************* ?sfas57&y  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 7)&}riQ  
    `-a](0Q U  
        'Adjust pupil diameter (trimming volume inner hole) Q72}V9I9  
    o5=1  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" J2A+x\{<  
    8m% +O#  
        ' Adjust pupil location to just in front of the lens )~/;Xl#b-  
        parID = FindFullName( "Geometry.Arizona Eye" ) irj{Or^k  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e$H N/O  
        count = 0 #oBMA  
        While GetOperationCount(eID)>count P$LHsg]  
            GetOperation eID, count, op zN}1Qh  
            If op.Type="ShiftZ" Then <T]BSQk  
                DeleteOperation eID,count QTZf e<m0  
                count=count-1 ( R2432R}J  
            End If /^_~NF#  
            count=count+1 5G5P#<Vv  
        Wend qKoD*cl)Za  
        op.Type = "ShiftZ" tQ!p<Q= $)  
        op.val1 = taq-0.01 @JJ,$ ?  
        op.parent = parID Axb,{X[6g  
        AddOperation eID, op 0\fV'JDOR  
    ,w>WuRN"  
        Print "Set pupil diameter = " & pupilDiam LxD >eA  
    u,h,;'J  
        'Update AZ Eye subassembly Description fL^+Qb}  
        eID = FindFullName( "Geometry.Arizona Eye" ) h)S223[  
        GetEntity eID, entity $ = uz  
        entity.Description = "Accommodation = " & A & "D" h#_KO-#.[  
        SetEntity eID, entity w-f[h  
    {+D 6o  
        Update )6K Q"*  
        Print "DONE!" ]/byz_7]  
         lw/zgR#|  
    End Sub 06hzCWm#  
    5R^e  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: &8kc0Z@y  
    3&H#LGoV$  
    Accommodation = 4 Diopters +Fn^@/?yC  
    Pupil Diameter = 4 mm ryhme\%l;f  
    Set aqueous humor thickness = 2.81 Kob i!  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 kjCXP  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 |>w>}w`~  
    Set lens thickness = 3.927 pwj?  
    Set lens index of refraction = 1.42672 t9zPUR  
    Set pupil diameter = 4 1oD1ia#  
    DONE! a4'KiA2r  
    2'R ;z< _  
    (文章来源:讯技光电)
     
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