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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 C26vH#C  
    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。 Idq &0<I  
    Qktj  
    模型 2WKYf0t  
    }N^A (`L  
    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。 dNQR<v\IL  
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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. <=]wh|D  
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    光源 Ch3{q/-g  
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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。 =dVPx<l5  
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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。 Z *9Qeu-N:  
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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。 W%3<"'eP  
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    图2. 字母F光源的设定方法光 !B&OK&*  
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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 =5 a|'O  
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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。 3#=%2\  
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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。 R2]2#3`  
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    图5. 视网膜重点采样规格设定
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    脚本 f!|$!r*q  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: Ia> 07av  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 }bU1wIW9I  
    余下的脚本计算与屈光度有关的所有参数。 4pYscB  
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    分析 vlygS(Y_7  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 e`N/3q7  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 OoG Nij  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. m1d*Lt>F@  
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    Dim entity As T_ENTITY +7`7cOqXg  
    Dim op As T_OPERATION RotWMGNK  
    Dim mat As T_MODELMATERIAL c.<bz  
    Dim A As Double uR;m<wPH,f  
    Dim pupilDiam As Double 2YS1%<-g*  
    Dim eID As Long }K rQPg  
    Dim parID As Long Wu{cE;t  
    Dim count As Integer (IE\}QcK  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double xcVF0%wVC  
    Dim tlens As Double, nlens As Double ^]{)gk8P~2  
    Dim curv As Double, conic As Double Eku+&f@RB  
    Dim ok As Long GL S`1!  
     qHU=X"rn  
    Sub Main <Qx]"ZP%  
    L}*s_'_e^>  
        '用户输入对话框 =!?4$vW  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 y3^>a5z!x  
            TextBox 220,21,40,21,.TextBox1 'default: 0 u{Rgk:bn  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 qm!&(8NfK  
            OKButton 40,91,90,21 MBjo9P(  
            CancelButton 190,91,90,21 [v,Y-}wQ)  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .huk>  
            TextBox 220,49,40,21,.TextBox2 'default: 4 8<2 [ F  
        End Dialog w1N-`S:  
        Dim dlg As UserDialog oP%'8%tk  
    ZLN79r{T  
        ok = Dialog (dlg) (E*pM$  
    t,v=~LE  
        If ok=0 Then    'cancel button was pressed aR c2#:~;  
            Print "Execution cancelled." UA%tI2  
            End oMw#ROsvC  
        End If JX $vz*KF  
    20NotCM  
        'Assign accommodation and pupil diameter & use defaults if field left empty *# 7 1aZ  
        If dlg.TextBox1 = "" Then uhf% z G  
            A = 0           'Default accommodation axpn*(yE  
        Else %]KOxaf_z  
            A = CDbl(dlg.TextBox1) ~HM,@5dFC  
        End If x&['g*[L0  
     4u.v7r  
        If dlg.TextBox2 = "" Then ?h1r6?Sug{  
            pupilDiam = 4   'Default pupil diameter )W0zu\fL =  
        Else ;_TPJy  
            pupilDiam = CDbl(dlg.TextBox2) 0|L%)'F  
        End If Iu=n$H  
    KhWt9=9  
        Print " " 7hq$vI%0  
        Print "Accommodation = " & A & " Diopters" iN]#XIQ%  
        Print "Pupil Diameter = " & pupilDiam & " mm" $I$ B8  
    '|jN!y^ 2p  
        ' Calculate new parameters with accommodation :'+- %xUM  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness w~lxWgaY7  
    \-2O&v'}  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 1P '_EJ]M  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens wpW3%r;9  
    tl@n}   
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens o'hwyXy/S  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens {] Zet}2  
    )r +o51gp  
        tlens = 3.767 + 0.04*A                  'Lens thickness '(S@9%,aK1  
    0;6 ^fiSY;  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ,|Xibfw  
    Q!&@aKl  
        'Adjust parameters to account for accommodation qe@ctHpn  
    7hLdCSX  
        '************************************************************************* IFd2r;W8  
        'Aqueous thickness (Position of Lens) +j">Ju6Q;.  
        '************************************************************************* 9D+B~8[SQ  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) )V6<'>1WZ  
        GetCustomElement eID, entity ~a RK=i$F  
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        parID = FindFullName( "Geometry.Arizona Eye" ) D?Y j5eOa  
    7L"Pe'Hw  
        ' Delete any shift(s) in z NMCMY<o  
        count = 0 \'}? j-8  
        While GetOperationCount(eID)>count d7)EzW|I;  
            GetOperation eID, count, op #sg^l>/*  
            If op.Type="ShiftZ" Then gb clk~kX  
                DeleteOperation eID,count :~gG]|F  
                count=count-1 *^WY+DV  
            End If E#I^D/0  
            count=count+1 k NnI$(H"H  
        Wend B+w< 0No  
    no`>r}C  
        'Set new shift in x 8v2mnk  
        op.Type = "ShiftZ" >qT4'1S*g  
        op.val1 = taq 9bVPMq7}i  
        op.parent = parID v_s(  
        AddOperation eID, op Hb :@]!r>  
        Print "Set aqueous humor thickness = " & taq-0.55 !U?Z<zh  
    <6(&w9WY  
        '************************************************************************* hiM nU  
        'Radius and conic constant of anterior lens }c1?:8p  
        '************************************************************************* }-8ZSWog6f  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) P!*G"^0<  
        GetConic eID, entity, curv, conic gWZzOH*  
    \as^z!<  
        SetConic eID, entity, 1/Rant, CCant PE7D)!d T  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant X$4MpXx  
    FLE2]cL-  
        '************************************************************************* c&rS7%  
        'Radius and conic constant of posterior lens lMN3;}K  
        '************************************************************************* I_\#(  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) #;WKuRv   
        GetConic eID, entity, curv, conic [fjP.kw;J  
    tXWh q  
        SetConic eID, entity, 1/Rpost, CCpost 2xEG s Q  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost '9R.$,N  
    k9|8@3(h  
        '************************************************************************* =,4iMENm!  
        'Lens thickness (Position of posterior lens surface) =Co[pt  
        '************************************************************************* 1[&V6=n  
    {*jo,<4ee  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0qPbmLMK  
    zP(UaSXz/  
        ' Delete any z-shift(s) v.~uJ.T  
        count = 0 Z<2j#rd  
        While GetOperationCount(eID)>count %0<-5&GE  
            GetOperation eID, count, op E#L"*vh  
            If op.Type="ShiftZ" Then PAUepO_  
                DeleteOperation eID,count -{tB&V~+v  
                count=count-1 ~s[St0  
            End If }bZcVc2  
            count=count+1 P nxxW?  
        Wend -? |-ux  
    &~SPDiu.t  
        'Set new z-shift MkCq$MA  
        op.Type = "ShiftZ" )8rN   
        op.val1 = tlens TcP (?v  
        op.parent = parID d>f.p"B.gj  
        AddOperation eID, op 0OrT{jo  
        Print "Set lens thickness = " & tlens ;:/<XfZ  
    A3#^R%2)W  
        '************************************************************************* km(Mv  
        'Lens index of refraction hj_%'kk-A  
        '************************************************************************* R;{y]1u  
        eID = FindMaterial( "Lens" ) IB sQaxt.  
        GetModelMaterial eID, mat *NEA(9  
    AdWLab;  
        mat.Nd = nlens pFZ2(b&  
        SetModelMaterial eID, mat 7Y?=ijXXx\  
        Print "Set lens index of refraction = " & nlens JTw3uM, e  
    .-[d6Pnw  
        '************************************************************************* rpZ^R}B%*v  
        'Pupil diameter bhqs%B!:  
        '************************************************************************* o_K. +^$  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Bn5O;I13  
    F*bmV>Qq  
        'Adjust pupil diameter (trimming volume inner hole) Uo7V)I;o  
    n> >!dg Og  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" @/w ($w"  
    "0&+ `7  
        ' Adjust pupil location to just in front of the lens ]0+5@c  
        parID = FindFullName( "Geometry.Arizona Eye" ) Y5Ub[o  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) fF\s5f#:  
        count = 0 kp4(_T7R  
        While GetOperationCount(eID)>count \U0p?wdr:  
            GetOperation eID, count, op (1|_Nr  
            If op.Type="ShiftZ" Then b/I_iJ8t  
                DeleteOperation eID,count Jbmi[` O  
                count=count-1  YXdd=F  
            End If %O! ~!'  
            count=count+1 [ ; $(;  
        Wend k!^Au8Up?  
        op.Type = "ShiftZ" 0rjH`H]M  
        op.val1 = taq-0.01 6;:s N8M+1  
        op.parent = parID $GR 3tLzK:  
        AddOperation eID, op C XZO  
    5c W2  
        Print "Set pupil diameter = " & pupilDiam T/A[C  
    TCC([  
        'Update AZ Eye subassembly Description rTgCmr'&  
        eID = FindFullName( "Geometry.Arizona Eye" ) Fk(+S:{yQ  
        GetEntity eID, entity sI7<rI.t){  
        entity.Description = "Accommodation = " & A & "D" lhyWlO  
        SetEntity eID, entity RkrZncBgV<  
    |@rPd=G^(/  
        Update 4^KeA".  
        Print "DONE!" AaVj^iy/X  
         EEU)eltI  
    End Sub P{'T9U|O-  
    ~ PO)>;  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: U|Du9_0  
    ~BS Ip .  
    Accommodation = 4 Diopters  u Z(vf  
    Pupil Diameter = 4 mm h7}D//~p  
    Set aqueous humor thickness = 2.81 ^ RS?y8  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 6eUM[C.  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 S#kA$yO  
    Set lens thickness = 3.927 xcF:moL  
    Set lens index of refraction = 1.42672 #`1@4,iC  
    Set pupil diameter = 4 aQMUC6cPM@  
    DONE! /4]<ro67E6  
    ] BJ]  
    (文章来源:讯技光电)
     
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