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    [转载]FRED运用:Arizona眼睛模型 [复制链接]

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    离线xunjigd
     
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    只看楼主 倒序阅读 楼主  发表于: 2016-02-24
    简介 \U$:/#1Oe  
    人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 kO\ O$J^S  
    I0+6p8,  
    模型 hS,&Nj+  
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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。 WML--<dU  
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    Table 1. AZ眼睛模型的定义
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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. M8~3 0L  
    3=d%WPgQ  
    光源 uN)c!='I  
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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。 hVF^ "$  
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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。 (I~   
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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。 VO0:4{-  
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    图2. 字母F光源的设定方法光 &G"s !:  
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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 N-K/jY  
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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。 *\XOQWrF  
    ^4fvV\ne_~  
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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。 "OenYiz  
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    图5. 视网膜重点采样规格设定
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    脚本 M=raKb?F  
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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: tpGT~Y(  
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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。 ;<M}ZL@m  
    余下的脚本计算与屈光度有关的所有参数。 uA#K59E+  
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    分析 oJ4HvrUO  
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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。 gHPJiiCv  
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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 )7 Mss/2T  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used.  @*eY~  
    8H4NNj Oy  
    Dim entity As T_ENTITY :Dt y([  
    Dim op As T_OPERATION &za }TH m  
    Dim mat As T_MODELMATERIAL )7& -DI1  
    Dim A As Double 9I/l+IS"X  
    Dim pupilDiam As Double +g g_C'"  
    Dim eID As Long TO.b- ;  
    Dim parID As Long ]`)5 Qe4  
    Dim count As Integer p9)YRLOh.  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double q=W.82.U  
    Dim tlens As Double, nlens As Double @MOQk  
    Dim curv As Double, conic As Double qGA|.I9,  
    Dim ok As Long ;d}>8w&tfy  
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    Sub Main Q#3}AO  
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        '用户输入对话框 2OJlE) .  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 s;I @En  
            TextBox 220,21,40,21,.TextBox1 'default: 0 svmb~n&x6  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 $0 .6No_|  
            OKButton 40,91,90,21 !K(  
            CancelButton 190,91,90,21 >UCg3uFj  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?XY'<]o E  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Tv"T+!Z  
        End Dialog i(|u g_^  
        Dim dlg As UserDialog y7>3hfn~w  
    5@xR`g-  
        ok = Dialog (dlg) ]jD\4\M}  
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        If ok=0 Then    'cancel button was pressed b\0>uU  
            Print "Execution cancelled." Z5'^81m$o  
            End yz K<yvN  
        End If }B'-*)^|e{  
    W+a/>U  
        'Assign accommodation and pupil diameter & use defaults if field left empty O5r8Ghf )  
        If dlg.TextBox1 = "" Then '! ^7 *@z  
            A = 0           'Default accommodation lW?}Ts ~'  
        Else )>1}I_1j)  
            A = CDbl(dlg.TextBox1) )IcSdS0@M  
        End If ?7Cm+J  
    D`@a*YIq  
        If dlg.TextBox2 = "" Then d'W2I*Zc<  
            pupilDiam = 4   'Default pupil diameter S%MDQTM  
        Else Xr K29a  
            pupilDiam = CDbl(dlg.TextBox2) T{ @@V  
        End If &lLk[/b  
    zd5=W"Y;]  
        Print " " 2FuV%\p  
        Print "Accommodation = " & A & " Diopters" B}TY+@  
        Print "Pupil Diameter = " & pupilDiam & " mm" I-^sJ@V;  
    :j`f%Vg~x  
        ' Calculate new parameters with accommodation `"65 _?B i  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ^gcB+  
    32K& IfV  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens !M8_PC*a  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens YA pC|R,^  
    "9P @bA  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ~u$ cX1M  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9KX% O-'  
    ; +\h$  
        tlens = 3.767 + 0.04*A                  'Lens thickness /!0&b?  
    -m}'I8  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction @K!JE w\  
    </;e$fh`  
        'Adjust parameters to account for accommodation ~T H4='4W3  
    d2eXN3"  
        '************************************************************************* iYBc4'X  
        'Aqueous thickness (Position of Lens) 0JtM|Mg  
        '************************************************************************* h F+aL  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) JE}VRMNr  
        GetCustomElement eID, entity I8!>7`L  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 6MM\nIU)/  
    P@@MQ[u?!.  
        ' Delete any shift(s) in z )!0}<_2  
        count = 0  jfK&CA  
        While GetOperationCount(eID)>count Tl yyJ{~  
            GetOperation eID, count, op 8TpYt)]S  
            If op.Type="ShiftZ" Then =)Hu(;Yv  
                DeleteOperation eID,count >bWpj8Kv  
                count=count-1 ;@S'8  
            End If WD\Yx~o  
            count=count+1 $B?8\>_?  
        Wend %ud-3u52M8  
    MUbKlX  
        'Set new shift in 0p.MH~mx  
        op.Type = "ShiftZ" 4*Hzys[{  
        op.val1 = taq Rw `ezC#  
        op.parent = parID 8SRUqe[H]  
        AddOperation eID, op ^Lb\k|U ,\  
        Print "Set aqueous humor thickness = " & taq-0.55 X~& 8^?  
    Ra53M!>]  
        '************************************************************************* 0?ab'vYcp  
        'Radius and conic constant of anterior lens q`PA~C];  
        '************************************************************************* jR}EBaI}  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) pNd`fV#jX  
        GetConic eID, entity, curv, conic :q3w;B~  
    JYj*.Q0  
        SetConic eID, entity, 1/Rant, CCant )U|V|yem'  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Gjeb)Y6N  
    =c \(]xX  
        '************************************************************************* ym5@SBqIx  
        'Radius and conic constant of posterior lens .aO6Y+Y  
        '************************************************************************* ~x(|'`  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @+t|Aa^g  
        GetConic eID, entity, curv, conic ! (lF#MG}  
    ch%zu%;f  
        SetConic eID, entity, 1/Rpost, CCpost Es#:0KH].v  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Z":m(}u O  
    ,{G\-(\  
        '************************************************************************* 5uG^`H@X  
        'Lens thickness (Position of posterior lens surface) 3.Mpd  
        '************************************************************************* .lj5pmD  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4A"nm6  
    ?8kFAf~  
        ' Delete any z-shift(s) ?i_/f}.K  
        count = 0 #Pk{emYW  
        While GetOperationCount(eID)>count F|6"-*[RS  
            GetOperation eID, count, op I}u\ov_Su  
            If op.Type="ShiftZ" Then 5\zR>Tg".  
                DeleteOperation eID,count s%y<FXUj  
                count=count-1 5JaLE5-  
            End If h-"q <eY"  
            count=count+1 ':}9>B3 S  
        Wend K:-jn}i?/  
     .?CaU  
        'Set new z-shift +d LUq2  
        op.Type = "ShiftZ" M 2| k.  
        op.val1 = tlens n;. M5}O  
        op.parent = parID ,&3+w ~Ua  
        AddOperation eID, op p:b{>lM  
        Print "Set lens thickness = " & tlens Oto8?4[n  
    * G*VY#L  
        '************************************************************************* >{(c\oMD  
        'Lens index of refraction du }HTrsC  
        '************************************************************************* -[vw 8  
        eID = FindMaterial( "Lens" ) 3}g>/F ~  
        GetModelMaterial eID, mat 2HVqJib4Yn  
    /L2ZI1v  
        mat.Nd = nlens }@6yROy.  
        SetModelMaterial eID, mat !Z>,dN  
        Print "Set lens index of refraction = " & nlens -*[)CR-{  
    >pZ _  
        '************************************************************************* QqF*SaO>  
        'Pupil diameter i@6g9\x+  
        '************************************************************************* 0LC]%x+"  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) "qC3%9e  
    q1YNp`]0i8  
        'Adjust pupil diameter (trimming volume inner hole) :(OV{ u  
    GGwwdB\x'  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 6(?@B^S>2  
    E`HA0/  
        ' Adjust pupil location to just in front of the lens Am3j:|>*  
        parID = FindFullName( "Geometry.Arizona Eye" ) o$->|k  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) A #SO}c  
        count = 0 Na]Z%#~  
        While GetOperationCount(eID)>count 4MDVR/Z7  
            GetOperation eID, count, op K)l*$h&-  
            If op.Type="ShiftZ" Then R~A))4<%%  
                DeleteOperation eID,count >cjxu9Vr1K  
                count=count-1  h8p{  
            End If ZTqt4H  
            count=count+1 H/[(T%]o  
        Wend S.iUiS"  
        op.Type = "ShiftZ" ,1|=_M31  
        op.val1 = taq-0.01 hiVDN"$$  
        op.parent = parID v@2?X4n  
        AddOperation eID, op QHje}  
    aH%tD!%,o  
        Print "Set pupil diameter = " & pupilDiam 8KP   
    R.* k7-(;  
        'Update AZ Eye subassembly Description ~ cu+QR)  
        eID = FindFullName( "Geometry.Arizona Eye" ) p}GTOJT}  
        GetEntity eID, entity OmK0-fa/  
        entity.Description = "Accommodation = " & A & "D" 2y$DTMu  
        SetEntity eID, entity xzMpTZQ  
    xPT$d,~"  
        Update nx`W!|g$`  
        Print "DONE!" {hO|{vz  
         2&s(:=  
    End Sub jMR9E@>~E  
    `.VkR5/  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: %^I 7=  
    ss|n7  
    Accommodation = 4 Diopters )('{q}JxV  
    Pupil Diameter = 4 mm 7~MWp4.   
    Set aqueous humor thickness = 2.81 DT;;4- {  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 YE"MtL {  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 T8T,G4Q  
    Set lens thickness = 3.927 '@hnqcqXq  
    Set lens index of refraction = 1.42672 RC"xnnIJv  
    Set pupil diameter = 4 |QH )A  
    DONE! :/Y4I)'  
    M tDJ1I%  
    (文章来源:讯技光电)
     
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