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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 gA/8Df\G:l  
    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。 )r +o51gp  
    Zf [#~4  
    模型 d8V)eZYXy~  
    TM?RH{(r  
    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。 !=t.AgmL  
    1#OM~v6B  
    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. ~ V:@4P  
    ^~65M/  
    光源 +kdZfv>  
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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。 w<54mGMOLr  
    S@WzvM  
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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。 JPt0k  
    HT@/0MF{J  
    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。 NR@n%p  
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    图2. 字母F光源的设定方法光 Y7L1`<SC  
    + NpH k  
    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 5N'Z"C0  
    sm1(I7y  
    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。 J-3%.fX,  
    >kN%R8*Sx  
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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。 U$+G9  
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    图5. 视网膜重点采样规格设定
    }0(.HMiGj  
    脚本 h+<F,0  
    ?--EIA8mfp  
    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: N*CcJp{Q  
    #y4+O;{  
    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
    ',g'Tl^E  
    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。 %=t8   
    余下的脚本计算与屈光度有关的所有参数。 NZh\{!  
    7yDWcm_y  
    分析 c&rS7%  
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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。 = "N?v-  
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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 +LEU|#  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6 $k"B/k  
    u#&ZD|  
    Dim entity As T_ENTITY UW?(-_8  
    Dim op As T_OPERATION BA 9c-Ay  
    Dim mat As T_MODELMATERIAL \dzHG/e  
    Dim A As Double %x2_njDd  
    Dim pupilDiam As Double D+u#!t[q  
    Dim eID As Long )>X C_ R  
    Dim parID As Long B{^ojV;]m  
    Dim count As Integer Z<2j#rd  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8:=EA3  
    Dim tlens As Double, nlens As Double E#L"*vh  
    Dim curv As Double, conic As Double PAUepO_  
    Dim ok As Long -{tB&V~+v  
    ~s[St0  
    Sub Main }bZcVc2  
    'q:t48&  
        '用户输入对话框 QwaAGUA  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 4* vV9*'!  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Y>l92=G  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 zK P{A Sk  
            OKButton 40,91,90,21 F6$QEiDu@  
            CancelButton 190,91,90,21 `c )//o  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?;dfA/  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Up/s)8$.  
        End Dialog F ^mMyK  
        Dim dlg As UserDialog "yo~;[  
    E Pgn2[z  
        ok = Dialog (dlg) 4-wCk=I  
    pg4J)<t#  
        If ok=0 Then    'cancel button was pressed *co=<g]4KY  
            Print "Execution cancelled." ofu {g  
            End >n^| eAH  
        End If <Z -d5D>  
    (i"@{[IP  
        'Assign accommodation and pupil diameter & use defaults if field left empty l1utk8'-  
        If dlg.TextBox1 = "" Then l\NVnXv:>  
            A = 0           'Default accommodation "kHQ}#6r  
        Else Gop;!aV1*  
            A = CDbl(dlg.TextBox1) ycr\vn t  
        End If 1$]hyC/f  
    s?JNc4q  
        If dlg.TextBox2 = "" Then h ?Ni5  
            pupilDiam = 4   'Default pupil diameter wy1xZQ<5  
        Else :k"VR,riF  
            pupilDiam = CDbl(dlg.TextBox2) O6[,K1,  
        End If x<S?"  
    c~0hu*&  
        Print " " )U~,q>H+ %  
        Print "Accommodation = " & A & " Diopters" =y>g:}G7  
        Print "Pupil Diameter = " & pupilDiam & " mm" >\x   
    xD#r5  
        ' Calculate new parameters with accommodation *s"dCc  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness \"X<\3z2  
    w[A$bqz   
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens <![]=~z $  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 20O\@}2q2M  
    BM@:=>ypQ  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens B}(+\Q$I  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens C_RxJWka  
    ^F*G  
        tlens = 3.767 + 0.04*A                  'Lens thickness )Hp{8c  
    )Yc jx~   
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction BfcpB)N&.K  
    O=9mLI6  
        'Adjust parameters to account for accommodation 9qHbV 9,M  
    Do3g^RD#  
        '************************************************************************* {5$.:Y  
        'Aqueous thickness (Position of Lens) ]4$t'wI.  
        '************************************************************************* 3%g\)Cs  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {!$E\e^d  
        GetCustomElement eID, entity bw@"MF{  
    L*rND15  
        parID = FindFullName( "Geometry.Arizona Eye" ) |#6B<'e'  
    0&YW#L|J  
        ' Delete any shift(s) in z RoG `U  
        count = 0 ?dJ[? <aG  
        While GetOperationCount(eID)>count  u Z(vf  
            GetOperation eID, count, op h7}D//~p  
            If op.Type="ShiftZ" Then ^ RS?y8  
                DeleteOperation eID,count 6eUM[C.  
                count=count-1 xUiSAKrcM  
            End If sO5~!W>Z  
            count=count+1 OMi_')J  
        Wend K KPQ[3g  
    *kliI]B F]  
        'Set new shift in w;LIP!T#  
        op.Type = "ShiftZ" q13bV  
        op.val1 = taq \fHtk _  
        op.parent = parID vp"b_x1-  
        AddOperation eID, op V*uoGWL]+  
        Print "Set aqueous humor thickness = " & taq-0.55 WB: NV=&^  
    DRo?7 _  
        '************************************************************************* cVx#dDdA  
        'Radius and conic constant of anterior lens LQ7.RK  
        '************************************************************************* 6@"lIKeP  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) th$?#4SbR  
        GetConic eID, entity, curv, conic ?"d25LyN  
    *?'^R c  
        SetConic eID, entity, 1/Rant, CCant QO0#p1fom'  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {z4v_[-2CF  
    yXuF<+CJ  
        '************************************************************************* iiWs]5  
        'Radius and conic constant of posterior lens )} I>"n  
        '************************************************************************* !rK,_wH  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) /M}jF*5N  
        GetConic eID, entity, curv, conic D*Cn!v$  
    QoGvjf3z  
        SetConic eID, entity, 1/Rpost, CCpost s/;iZiWK  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost rF/k$_bFt  
    xnBU)#<]S  
        '************************************************************************* 6AM-^S@  
        'Lens thickness (Position of posterior lens surface)  rq[+p  
        '************************************************************************* D7 D:?VoR  
    -^Pn4y]A)  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *8ZaG]L  
    j}uVT2ZE%  
        ' Delete any z-shift(s) 9Y6Ear .W  
        count = 0 _{eH" ,(  
        While GetOperationCount(eID)>count F5hOKUjv  
            GetOperation eID, count, op TA2?Ia;@xV  
            If op.Type="ShiftZ" Then &!kD81?Mm  
                DeleteOperation eID,count 8&g`Uy/b  
                count=count-1 &jg..R  
            End If ([mC!d@a  
            count=count+1 sQ4~oZZ  
        Wend i`FskEoijq  
    0q@U>#  
        'Set new z-shift *dTI4k  
        op.Type = "ShiftZ" cZ<@1I5QK  
        op.val1 = tlens }JF,:g Lk  
        op.parent = parID '@{'T LMCi  
        AddOperation eID, op T i{~  
        Print "Set lens thickness = " & tlens ~{8X$xs  
    <~rf;2LZ  
        '************************************************************************* LW"p/`#<  
        'Lens index of refraction UBgheu  
        '************************************************************************* ?qdZ]M4e  
        eID = FindMaterial( "Lens" ) \-Oq/g{j  
        GetModelMaterial eID, mat Po ,zTz   
    myR}~Cj;q  
        mat.Nd = nlens 6 4fB$  
        SetModelMaterial eID, mat yY 3Mv/R  
        Print "Set lens index of refraction = " & nlens QSaJb?I  
    b?=>)':f  
        '************************************************************************* g9rsw7  
        'Pupil diameter l$>))cW!  
        '************************************************************************* p+t79F.js  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) f|U J%}$v;  
    v>4kF _N  
        'Adjust pupil diameter (trimming volume inner hole) *c 0\<BI  
    JdP[ cN  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" kVH^(Pi  
    AP2BND9  
        ' Adjust pupil location to just in front of the lens )|Ho"VEmg  
        parID = FindFullName( "Geometry.Arizona Eye" ) zv Dg1p  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) wva| TZ  
        count = 0 _olhCLIR-  
        While GetOperationCount(eID)>count Ot^<:\< `G  
            GetOperation eID, count, op 4X()D {uR  
            If op.Type="ShiftZ" Then , :10  
                DeleteOperation eID,count 0c pI2  
                count=count-1 EYsf<8cl  
            End If lrE|>R  
            count=count+1 h=1cD\^|qw  
        Wend '&|]tu:q  
        op.Type = "ShiftZ" ~&UfnO  
        op.val1 = taq-0.01 f`[gRcZ-  
        op.parent = parID x}c%8dO#J  
        AddOperation eID, op @S-p[u  
    -kv'C6gB  
        Print "Set pupil diameter = " & pupilDiam &ND8^lR=Y;  
    E&RiEhuv  
        'Update AZ Eye subassembly Description ;)SWUXa;{  
        eID = FindFullName( "Geometry.Arizona Eye" ) pYtvenBy  
        GetEntity eID, entity ,rO>5$w.  
        entity.Description = "Accommodation = " & A & "D" ~@v<B I  
        SetEntity eID, entity WX2w7O'R  
    ~<)CI0=  
        Update t!u{sr{j=  
        Print "DONE!" I1TzPe  
         \0^ZNa?  
    End Sub :kaHvf  
    {e3XmVAI  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: :We}l;.jQ  
    o|FY-+  
    Accommodation = 4 Diopters clcj5=:  
    Pupil Diameter = 4 mm !R`)S7!  
    Set aqueous humor thickness = 2.81 fV\ eksBF  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 %)|_&Rh  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 gk*Md+  
    Set lens thickness = 3.927 xIrRFK9[Q  
    Set lens index of refraction = 1.42672 r2Wx31j{  
    Set pupil diameter = 4 M[Kk43;QY!  
    DONE! 3XOf-v:~  
    4ZRE3^y\"  
    (文章来源:讯技光电)
     
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