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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 h`D+NZtWm  
    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。 rW2l+:@c  
    k^%F4d3z@C  
    模型 H284 ]i  
    qdZo cTf'  
    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。 Sr-!-eC  
    |iVw7M:  
    Table 1. AZ眼睛模型的定义
    qSQsY:]j0  
    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. Vah.tOU  
    FD.L{  
    光源 CMfR&G,)  
    Px`z$~*B:  
    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 t.] e8=dE  
    ;h4w<OqcM  
    4K!@9+Mz  
    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 eSSv8 [u  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 @qB1:==@7  
    (oB9$Zz!t  
    图2. 字母F光源的设定方法光 7.B]B,]  
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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 SI;SnF'[7  
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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。 k5)e7Lb(  
    C6c]M@6  
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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。 ,IG?(CK|  
    ^/jALA9!  
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    图5. 视网膜重点采样规格设定
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    脚本 } mEsb?  
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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: `L {dF  
    /qO?)p3gk  
    图6. 用户对话框的创建与编辑
    :_+Fe,h>|  
    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。 e[J0+ x#;r  
    余下的脚本计算与屈光度有关的所有参数。 b{lkl?@a  
    *M()z.N  
    分析 G1:2MPH  
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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。 RLX?3u&  
    .\b# 0w  
    图7. 字母F在视网膜上颜色分析
    x2H?B` 5  
    脚本代码 #:M)a?E/%  
    } T1~fa  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. >-YWq  
    HtGGcO'bqg  
    Dim entity As T_ENTITY k{j (Gb2sp  
    Dim op As T_OPERATION 9oJ=:E~CP  
    Dim mat As T_MODELMATERIAL *dm?,~f%<  
    Dim A As Double lBnG!!VrWa  
    Dim pupilDiam As Double I4^}C;p0?  
    Dim eID As Long _J`q\N K  
    Dim parID As Long q=h~zjQ?R  
    Dim count As Integer &d^u$Y5  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]Vgl  
    Dim tlens As Double, nlens As Double Ga} &%  
    Dim curv As Double, conic As Double aqAWaO  
    Dim ok As Long JOJ? .H&su  
    VC@{cVT  
    Sub Main R2$;f?;:  
    y #Xq@  
        '用户输入对话框 wH Q$F(by  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 G' 'l,\3  
            TextBox 220,21,40,21,.TextBox1 'default: 0 \Q<Ur&J]%  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 _oJq32  
            OKButton 40,91,90,21 _P*<T6\J>  
            CancelButton 190,91,90,21 Y l1sAf/  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )R`w{V  
            TextBox 220,49,40,21,.TextBox2 'default: 4 *PjW,   
        End Dialog |4s`;4c&  
        Dim dlg As UserDialog 30v 3C7o=  
    -5 YvtL  
        ok = Dialog (dlg) Z;#Ei.7p|  
    `Vqp o/  
        If ok=0 Then    'cancel button was pressed Y|iJO>_Uu=  
            Print "Execution cancelled." GKNH{|B$D  
            End |Skk1 #  
        End If a}+7MEUmZ/  
    R1DXi  
        'Assign accommodation and pupil diameter & use defaults if field left empty Xbb('MoI63  
        If dlg.TextBox1 = "" Then PDnwaK   
            A = 0           'Default accommodation }#/,nJm'  
        Else 1MCHwX3/  
            A = CDbl(dlg.TextBox1) P]@m0f  
        End If 'e4  ;,m  
    \e/'d~F  
        If dlg.TextBox2 = "" Then IP`;hC  
            pupilDiam = 4   'Default pupil diameter + fQ=G/  
        Else u8Au `  
            pupilDiam = CDbl(dlg.TextBox2) b1}P3W  
        End If a N|MBX;  
    pA*cF!tq 7  
        Print " " bX:ARe O  
        Print "Accommodation = " & A & " Diopters" DM*mOT  
        Print "Pupil Diameter = " & pupilDiam & " mm" 6uYCU|JsU  
    Zq--m/  
        ' Calculate new parameters with accommodation &Oq& ikw  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness T/" 6iv\1  
    -VESe}c:nQ  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens K>TdN+Z}=  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens wPDA_ns~  
    u$N2uFc  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens | 1Fy  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens .ya^8gM  
    byYdX'd.  
        tlens = 3.767 + 0.04*A                  'Lens thickness tVZj tGz=  
    J>P{8Aw  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L_.BcRy  
    .pgTp X   
        'Adjust parameters to account for accommodation .VVY]>bJg@  
    &P%3'c}G  
        '************************************************************************* bGvALz'  
        'Aqueous thickness (Position of Lens) 0)V<)"i  
        '************************************************************************* b:Lp`8Du  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) [e )j,Q1  
        GetCustomElement eID, entity bmEo5f~C!  
    Zi=Nr3b  
        parID = FindFullName( "Geometry.Arizona Eye" ) M?4)U"_VE  
    )k0P' zGb  
        ' Delete any shift(s) in z Yw=Ve 0  
        count = 0 kmM1)- v  
        While GetOperationCount(eID)>count m9UI3fBX  
            GetOperation eID, count, op d*=P8QwL|  
            If op.Type="ShiftZ" Then }"<|.[V)  
                DeleteOperation eID,count /a\6&Eb  
                count=count-1 ln7{c #lE  
            End If edqekjh  
            count=count+1 D L_{q6ZK  
        Wend bE2^sx`(  
    \cdNyVY  
        'Set new shift in maLKUSgo  
        op.Type = "ShiftZ" SUXRWFl  
        op.val1 = taq "_JGe#=  
        op.parent = parID FW:x XK  
        AddOperation eID, op *doK$wYP  
        Print "Set aqueous humor thickness = " & taq-0.55 z!5^UD8"W  
    &}S#6|[i  
        '************************************************************************* ^WP`;e  
        'Radius and conic constant of anterior lens a3 <D1"  
        '************************************************************************* "P=OpFV  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 5C/W_H+9iK  
        GetConic eID, entity, curv, conic <8p53*a  
    , gk49z9  
        SetConic eID, entity, 1/Rant, CCant *z`_U]tP  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant "jzU`  
    8*3<Erv  
        '************************************************************************* 3qPj+@  
        'Radius and conic constant of posterior lens DPJ#Y -0  
        '************************************************************************* ~AxA ,  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 3(':4Tas  
        GetConic eID, entity, curv, conic &IM;Yl  
    nnX,_5s  
        SetConic eID, entity, 1/Rpost, CCpost v2:A 4Pd:+  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Tm5]M$)  
    @.T '>;izr  
        '************************************************************************* FyX\S=  
        'Lens thickness (Position of posterior lens surface) ["4h%{.  
        '************************************************************************* s_ -G`xT>{  
    <<gk< _7`  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) LY[XPV]t  
    zRdL-u%(#  
        ' Delete any z-shift(s) <\GP\G  
        count = 0 `3^ *K/K\  
        While GetOperationCount(eID)>count D)XF@z;  
            GetOperation eID, count, op EA9`-xs|  
            If op.Type="ShiftZ" Then >6Y\CixN  
                DeleteOperation eID,count y^tuybpZY<  
                count=count-1 @FKNB.>  
            End If %geiJ z  
            count=count+1 ";yCo0*  
        Wend "tB"C6b  
    ULqnr@/FbK  
        'Set new z-shift @dQIl#  
        op.Type = "ShiftZ" a:Js i=  
        op.val1 = tlens 4G0Er?D   
        op.parent = parID "5u*C#T2$  
        AddOperation eID, op .w\AyXp  
        Print "Set lens thickness = " & tlens R)d1]k8  
    x2 /\%!mt  
        '************************************************************************* An!1>`8r  
        'Lens index of refraction YU.aZdA&V3  
        '************************************************************************* %KK6}d #  
        eID = FindMaterial( "Lens" ) [ !/u,  
        GetModelMaterial eID, mat Y&KI/]ly,L  
    `P<}MeJ\l  
        mat.Nd = nlens ?Z= %I$i  
        SetModelMaterial eID, mat ]#;;)K}>  
        Print "Set lens index of refraction = " & nlens T;qP"KWZ  
    -jdS8n4  
        '************************************************************************* 6gV-u~j[#  
        'Pupil diameter P:vAU8d>  
        '************************************************************************* Meo(|U  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;75K:_  
    Aq%TZ_m  
        'Adjust pupil diameter (trimming volume inner hole) +<7~yZ[Z8  
    P2pdXNV  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" e/JbRbZX  
    B-PN +P2  
        ' Adjust pupil location to just in front of the lens "n3r,  
        parID = FindFullName( "Geometry.Arizona Eye" ) 6r{NW9y'  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) |;e K5(|  
        count = 0 ~kPHf_B;z  
        While GetOperationCount(eID)>count L#mf[a@pCn  
            GetOperation eID, count, op <VI.A" Qk~  
            If op.Type="ShiftZ" Then xX$'u"dsA  
                DeleteOperation eID,count >J!4x(;Yh  
                count=count-1 "/[xak!g  
            End If tIfA]pE  
            count=count+1 N,fEta6  
        Wend !qk+>6~A,  
        op.Type = "ShiftZ" -J*BY2LU3f  
        op.val1 = taq-0.01 ewHk (ru  
        op.parent = parID '4k l$I  
        AddOperation eID, op  #v+ 2W  
    7pf]h$2  
        Print "Set pupil diameter = " & pupilDiam 4H'\nsM  
    .anXsjD%W  
        'Update AZ Eye subassembly Description 3gtQS3$4s  
        eID = FindFullName( "Geometry.Arizona Eye" ) DCr&%)Ll  
        GetEntity eID, entity T1AD(r\W5  
        entity.Description = "Accommodation = " & A & "D" 0N.B =j|  
        SetEntity eID, entity L!G]i;=:  
    ?e( y/  
        Update *YH5kX  
        Print "DONE!" mU@pRjq=  
         dC+WII`V  
    End Sub }2c)UQD8  
    +l'l*<  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: Kv(2x3("  
    [Z~h!}  
    Accommodation = 4 Diopters !YX$4_I  
    Pupil Diameter = 4 mm mY6d+  
    Set aqueous humor thickness = 2.81 "LZQ1P*ef$  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 Ai>=n;  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 \cJ?2^Eq  
    Set lens thickness = 3.927 #o`y<1rN  
    Set lens index of refraction = 1.42672 KA~eOEj M  
    Set pupil diameter = 4 b)ytm=7ha  
    DONE! zv[$ N,  
    L_4c~4  
    (文章来源:讯技光电)
     
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