[转载]FRED运用：Arizona眼睛模型 [复制链接]

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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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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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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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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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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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
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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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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 xak  
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~  
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Sub Main EM!9_8 f  
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    '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 I8VCR
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        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_  
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    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:~=  
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    '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`  

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    If dlg.TextBox2 = "" Then @bZ,)R  
        pupilDiam = 4   'Default pupil diameter 6Cgc-KNbk  
    Else hkx(r5o  
        pupilDiam = CDbl(dlg.TextBox2) Lm*PHG  
    End If +!$]a^3l  
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    Print " " }70A>JBw  
    Print "Accommodation = " & A & " Diopters" ,PeE'$q  
    Print "Pupil Diameter = " & pupilDiam & " mm" aole`PD,l  
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    ' Calculate new parameters with accommodation TNlOj a:  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness -l?\hmDl  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens {!^0j{T  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ^/~C\ (  
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    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?  
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    tlens = 3.767 + 0.04*A                  'Lens thickness {\gpXVrn_  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction #'BPW<Ob  
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    'Adjust parameters to account for accommodation F
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    '************************************************************************* +#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%  
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    ' 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:  
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    'Set new shift in a}X.e
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    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  
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    '************************************************************************* 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|
 
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    '************************************************************************* \2CEEs'  
    'Radius and conic constant of posterior lens /0Mt-8[  
    '************************************************************************* dSe d6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Dt(xj}[tC  
    GetConic eID, entity, curv, conic D 9UM8Hxi  
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    SetConic eID, entity, 1/Rpost, CCpost )y{:Uc\4!  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost O=6[/oc '  
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    '************************************************************************* {C0Y8:"`  
    'Lens thickness (Position of posterior lens surface) kn/xt  
    '************************************************************************* 1iqgVby  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) M3r;Pdj2r  
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    ' 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](
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        count=count+1 >GLoeCRNu  
    Wend {h PB%  
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    '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$~Pb  
    Print "Set lens thickness = " & tlens jAU&h@  
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    '************************************************************************* mxpj<^n}  
    'Lens index of refraction t#3_M=L  
    '************************************************************************* AyPtbrO  
    eID = FindMaterial( "Lens" ) qDU4W7|T`  
    GetModelMaterial eID, mat g>k?03;  
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    mat.Nd = nlens i,S1|R  
    SetModelMaterial eID, mat ~Z!YB,)bp  
    Print "Set lens index of refraction = " & nlens klH?
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    '************************************************************************* [YZgQ  
    'Pupil diameter :Zx|=  
    '************************************************************************* (w:,iw#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #<Lv&-U<KT  
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    'Adjust pupil diameter (trimming volume inner hole) )WInPW  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Z4rk$K'=1w  
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    ' 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 w52py7  
        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$q  
    op.parent = parID 8>Cf}TvErx  
    AddOperation eID, op +:4>4=  
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    Print "Set pupil diameter = " & pupilDiam _U-`/r o  
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    'Update AZ Eye subassembly Description +ima$a0Zyt  
    eID = FindFullName( "Geometry.Arizona Eye" ) 3T0~k--  
    GetEntity eID, entity yNowhh
 
    entity.Description = "Accommodation = " & A & "D" {\CWoFht>  
    SetEntity eID, entity /I!62?)-*  
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    Update BAY e:0  
    Print "DONE!"  WZY+c
 
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End Sub Y0T:%  
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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： kfZ`|w@q  
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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@
 
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