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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 !]2`dp\!  
    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。 0+6=ag%  
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    模型 4v;KtD;M  
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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。 N.dcQQ_iS  
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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. @ w?,7i-S  
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    光源 DQ9}( '^  
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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。 t 4>\ ;  
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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。 mV#U=zqb!S  
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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。 >\'gIIs  
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    图2. 字母F光源的设定方法光 ,| ~Pa  
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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 [BuAJ930#5  
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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。 @f`s%o  
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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。 sPRo=LB  
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    图5. 视网膜重点采样规格设定
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    脚本 A75z/O{  
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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: kS< 9cy[O  
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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。 =&#t ("  
    余下的脚本计算与屈光度有关的所有参数。 |SuN3B4e  
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    分析 M sQ=1  
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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。 f J+  
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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 2 sK\.yS  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. Ah_0o_Di  
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    Dim entity As T_ENTITY ?b xa k  
    Dim op As T_OPERATION ca,U>'(y  
    Dim mat As T_MODELMATERIAL w:/QB-`%  
    Dim A As Double s_cur-  
    Dim pupilDiam As Double WP >VQZ&  
    Dim eID As Long xP $\ }  
    Dim parID As Long S=qx,<J 39  
    Dim count As Integer |vgYi  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double qL~|bfN  
    Dim tlens As Double, nlens As Double 7uq^TO>9f  
    Dim curv As Double, conic As Double 5U6b\jxX  
    Dim ok As Long E(Zm6~  
    =i>i,>bv  
    Sub Main EM!9_8 f  
    \?"p]&2UcB  
        '用户输入对话框 @P/6NMjZ^  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 !YIW8SP)  
            TextBox 220,21,40,21,.TextBox1 'default: 0 u1ahAk7  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ?xw0kXK4  
            OKButton 40,91,90,21 I 8VCR8q  
            CancelButton 190,91,90,21 6-QcHJ>m6U  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 6xoCB/]  
            TextBox 220,49,40,21,.TextBox2 'default: 4 5G l:jRu  
        End Dialog r>g5_"FL  
        Dim dlg As UserDialog 0ni/!}YP_  
    ahg]OWn#  
        ok = Dialog (dlg) ,tak{["  
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        If ok=0 Then    'cancel button was pressed +^ `n- m  
            Print "Execution cancelled." USzO):o  
            End [}`-KpV!;  
        End If uA~?z :~=  
    2#R8}\  
        'Assign accommodation and pupil diameter & use defaults if field left empty gm =LM=  
        If dlg.TextBox1 = "" Then ="de+S8W  
            A = 0           'Default accommodation rY295Q  
        Else UeU`U  
            A = CDbl(dlg.TextBox1) "mc ]^ O  
        End If lsKQZ@LN`  
    ,M=s3D8C  
        If dlg.TextBox2 = "" Then @bZ,)R  
            pupilDiam = 4   'Default pupil diameter 6Cgc-KNbk  
        Else hkx(r5o  
            pupilDiam = CDbl(dlg.TextBox2) Lm*PHG  
        End If +!$]a^3l  
    2*a5pFkb  
        Print " " }70A>JBw  
        Print "Accommodation = " & A & " Diopters" ,PeE'$q  
        Print "Pupil Diameter = " & pupilDiam & " mm" aole`PD,l  
    _kdt0Vr,L  
        ' Calculate new parameters with accommodation TNlOj a:  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness -l ?\hmDl  
    =Y5_@}\0  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens {!^0j{T  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ^/~C\ (  
    z@v2t>@3k  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ^Vg-fO]V  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens vrIWw?/z?  
    +P<#6<gR  
        tlens = 3.767 + 0.04*A                  'Lens thickness {\gpXVrn_  
    3L9@ELY4  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction #'BPW<Ob  
    RO[6PlrRN  
        'Adjust parameters to account for accommodation FT\%=>{  
    ]Rj?OSok  
        '************************************************************************* +#9 4 X)*  
        'Aqueous thickness (Position of Lens) <[?ZpG  
        '************************************************************************* S=G2%u!;  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?{\h`+A  
        GetCustomElement eID, entity ,,]<f*N  
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        parID = FindFullName( "Geometry.Arizona Eye" ) Mk}*ze0%  
    otlv ;3263  
        ' Delete any shift(s) in z =k5O*ql"  
        count = 0  vUR gR  
        While GetOperationCount(eID)>count .mplML0oW  
            GetOperation eID, count, op /Ow@CB  
            If op.Type="ShiftZ" Then LIn2&r:U  
                DeleteOperation eID,count ,n$NF0^l  
                count=count-1 (U@$gkUx}G  
            End If F<DXPToX%  
            count=count+1 (XEJd4r  
        Wend TQth"Cv2:  
    i5gNk)D  
        'Set new shift in a}X. ewg  
        op.Type = "ShiftZ" &]pY~zVc  
        op.val1 = taq a|z@5r%  
        op.parent = parID z fu)X!t^  
        AddOperation eID, op pA6A*~QE  
        Print "Set aqueous humor thickness = " & taq-0.55 xtut S  
    biENRJQ.  
        '************************************************************************* gv1y%(`|n(  
        'Radius and conic constant of anterior lens KbMan~Pb6  
        '************************************************************************* iXL?ic  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) gux?P2f  
        GetConic eID, entity, curv, conic odn3*{c{x  
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        SetConic eID, entity, 1/Rant, CCant a%5/Oc[[  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant PJ\k|  
    @hy~H?XN  
        '************************************************************************* \2CEEs'  
        'Radius and conic constant of posterior lens /0Mt-8[  
        '************************************************************************* dSe d 6  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Dt(xj}[tC  
        GetConic eID, entity, curv, conic D 9UM8Hxi  
    -d^'-s  
        SetConic eID, entity, 1/Rpost, CCpost )y{:Uc\4!  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost O=6[/oc '  
    D@kf^1G  
        '************************************************************************* {C0Y8:"`  
        'Lens thickness (Position of posterior lens surface) kn/xt  
        '************************************************************************* 1iqgVby  
    MjWxfW/  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) M3r;Pdj2r  
    f Xh{ _>  
        ' Delete any z-shift(s) txE+A/>i9  
        count = 0 dsH*9t:z  
        While GetOperationCount(eID)>count 5vJxhBm/  
            GetOperation eID, count, op ~/XDA:nfL:  
            If op.Type="ShiftZ" Then 3O;"{E= <  
                DeleteOperation eID,count '.C#"nY>1  
                count=count-1 #\_ 8y`{x  
            End If P](8Qrl  
            count=count+1 >GLoeCRNu  
        Wend {h PB%  
    Pm,.[5uc  
        'Set new z-shift k SgE_W)  
        op.Type = "ShiftZ" _?bO /y_y  
        op.val1 = tlens /4@ [^}x  
        op.parent = parID O<E8,MCA[a  
        AddOperation eID, op x=+>J$~Pb  
        Print "Set lens thickness = " & tlens jAU&h@  
    Cc;8+Z=a?G  
        '************************************************************************* mxpj<^n}  
        'Lens index of refraction t#3 _M=L  
        '************************************************************************* AyPtbrO  
        eID = FindMaterial( "Lens" ) qDU4W7|T`  
        GetModelMaterial eID, mat g>k?03;  
    @BG].UJo  
        mat.Nd = nlens i,S1|R  
        SetModelMaterial eID, mat ~Z!YB,)bp  
        Print "Set lens index of refraction = " & nlens klH?!r&  
    @b,6W wc  
        '************************************************************************* [YZgQ  
        'Pupil diameter :Z x|=  
        '************************************************************************* (w:,iw#  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #<Lv&-U<KT  
    <XQwu*_\  
        'Adjust pupil diameter (trimming volume inner hole) )WInPW  
     .FC+  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Z4rk$K'=1w  
    *ra>Kl0   
        ' Adjust pupil location to just in front of the lens A^#\=ZBg1  
        parID = FindFullName( "Geometry.Arizona Eye" ) v/=\(  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) \P")Eh =d  
        count = 0 U|VL+9#hd  
        While GetOperationCount(eID)>count *HUXvX|-%  
            GetOperation eID, count, op a(=lQ(v/?  
            If op.Type="ShiftZ" Then Ie|5,qw E  
                DeleteOperation eID,count :~#)Xa0I  
                count=count-1 w52p y7  
            End If x^1d9Z  
            count=count+1 GM?s8yZ<  
        Wend gPb.%^p  
        op.Type = "ShiftZ" C*3St`2@9  
        op.val1 = taq-0.01 Em^~OM3U$q  
        op.parent = parID 8>Cf}TvErx  
        AddOperation eID, op +:4>4=  
    &$ "J\v m  
        Print "Set pupil diameter = " & pupilDiam _U-`/r o  
    @!u{>!~0  
        'Update AZ Eye subassembly Description +ima$a0Zyt  
        eID = FindFullName( "Geometry.Arizona Eye" ) 3T0~k--  
        GetEntity eID, entity yNow hh  
        entity.Description = "Accommodation = " & A & "D" {\CWoFht>  
        SetEntity eID, entity /I!62?)-*  
    $#p5BQQ|  
        Update BAY e:0  
        Print "DONE!"  WZY+c  
         ENIg_s4  
    End Sub Y0T:%  
    `[g$EXX  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: kfZ`|w@q  
    Qrg- xu=  
    Accommodation = 4 Diopters "YY<T&n  
    Pupil Diameter = 4 mm  Pd\4hy  
    Set aqueous humor thickness = 2.81 @j_o CDS  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 XsQ81j.  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 t!*[nfR  
    Set lens thickness = 3.927 ?d^6ynzn  
    Set lens index of refraction = 1.42672 _uLpU4# ?  
    Set pupil diameter = 4 -grmmE]/  
    DONE! pu]U_Ll@  
    /51$o\4 S  
    (文章来源:讯技光电)
     
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