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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 't (O$  
    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。 |\9TvN^$`  
    _t>"5s&i  
    模型 |Ul,6K@f"5  
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    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 v ! hY  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. ~}9PuYaD@  
    [3>GGX[Ic  
    光源 PS>x,T  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 sfD5!Z9#1  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 }d Ad$^  
    5]Da{Wmgs  
    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。 Nn6S 8kc  
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    图2. 字母F光源的设定方法光 L EWhb!U  
    _S?qDG{E|  
    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 @_ygnNn4R  
    ) ]6h y9<  
    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。 ~Qj}ijWD  
    P }7zE3V  
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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。 (c\hy53dP  
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    图5. 视网膜重点采样规格设定
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    脚本 K`%tGVY  
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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: [3/VCYje  
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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。 Jl<ns,Zg  
    余下的脚本计算与屈光度有关的所有参数。   WY  
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    分析 ?? qq:`s  
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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。 X$?3U!  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 BzJ;%ywS  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?}p:J{  
    _c(4o:  
    Dim entity As T_ENTITY R3.*dqo$  
    Dim op As T_OPERATION (K..k-o`.  
    Dim mat As T_MODELMATERIAL 0$.m_0H  
    Dim A As Double L{{CAB!  
    Dim pupilDiam As Double L,[;k  
    Dim eID As Long < Bg8,;  
    Dim parID As Long ]B\H ~Kn  
    Dim count As Integer ,Ds.x@p  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double s0u{d qP  
    Dim tlens As Double, nlens As Double {MdLX.ycc)  
    Dim curv As Double, conic As Double RD,5AShP  
    Dim ok As Long v;1F[?@3Y  
    ksR1k vTm  
    Sub Main CO+/.^s7}S  
    RI n9(r  
        '用户输入对话框 N 5zlT  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vV?rpe|%  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Lv[OUW#S  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 SGc8^%-`  
            OKButton 40,91,90,21 F/d7q%I  
            CancelButton 190,91,90,21 una%[jTc  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 _6@hTen`  
            TextBox 220,49,40,21,.TextBox2 'default: 4 P(k(m< 0  
        End Dialog Q^Ql\  
        Dim dlg As UserDialog "Ml&[O ge  
    e-hjC6Q U  
        ok = Dialog (dlg) RkEN ,xWE  
    :G w~7v_  
        If ok=0 Then    'cancel button was pressed #EGA#SKoq  
            Print "Execution cancelled." &QX`NO 6  
            End Z(>'0]G  
        End If I&|f'pn^<  
    ?']h%'Q  
        'Assign accommodation and pupil diameter & use defaults if field left empty uQb!=]  
        If dlg.TextBox1 = "" Then wd@aw/  
            A = 0           'Default accommodation w2O!M!1  
        Else X.F^$  
            A = CDbl(dlg.TextBox1)  Qe"pW\  
        End If nwt C:*}  
    RR;AJ8wd  
        If dlg.TextBox2 = "" Then UM*jKi2]"  
            pupilDiam = 4   'Default pupil diameter f ).1]~  
        Else y)c5u%(  
            pupilDiam = CDbl(dlg.TextBox2) wu9=N ^x  
        End If )&{K~i;:  
    l%R50aL  
        Print " " g$:Xuw1  
        Print "Accommodation = " & A & " Diopters" Z+`{7G?4m  
        Print "Pupil Diameter = " & pupilDiam & " mm" 8;Fn7k_Uf  
    2O"P2(1}v  
        ' Calculate new parameters with accommodation \o-&f:  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Rv,JU6>i  
    R1:k23{  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens PfS:AI y  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Xd E`d.  
    g[>\4B9t  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens dm "n%  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens h0oMTiA  
    Ll4bdz,  
        tlens = 3.767 + 0.04*A                  'Lens thickness y|&}.~U[  
    qzw'zV  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction kL7#W9  
    MaBYk?TR~  
        'Adjust parameters to account for accommodation  rdnno  
    8By,#T".  
        '************************************************************************* 0yx3OY  
        'Aqueous thickness (Position of Lens) cWGDee(  
        '************************************************************************* 9%ii '{  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) fW`&'!  
        GetCustomElement eID, entity 8;y&Pb~)  
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        parID = FindFullName( "Geometry.Arizona Eye" ) cw&Hgjj2  
    jEc|]E  
        ' Delete any shift(s) in z PN~@  
        count = 0 Sp}D ;7  
        While GetOperationCount(eID)>count {:c]|^w6  
            GetOperation eID, count, op 8,O33qwH  
            If op.Type="ShiftZ" Then ~.PO[hC  
                DeleteOperation eID,count "M|P+A  
                count=count-1 9p 4"r^  
            End If z 3t~}aL  
            count=count+1 4RKW  
        Wend !@u>A_  
    RUCPV[{b  
        'Set new shift in h0?2j)X_  
        op.Type = "ShiftZ" 3:"]Rn([P  
        op.val1 = taq Md)zEj`\  
        op.parent = parID GN#<yv$av  
        AddOperation eID, op hA 3HVP_  
        Print "Set aqueous humor thickness = " & taq-0.55 l ?Y_~Wuw  
    5`~mmAUk;`  
        '************************************************************************* ERUt'1F?]  
        'Radius and conic constant of anterior lens $&|y<Y=  
        '************************************************************************* f:zFFpP.j@  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) )f+U~4G&  
        GetConic eID, entity, curv, conic X.ONa_  
    _!xD8Di#  
        SetConic eID, entity, 1/Rant, CCant K\[!SXg@  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant -71dN0hWh  
    [LT^sb  
        '************************************************************************* q,<[hBri-  
        'Radius and conic constant of posterior lens 2y0J`!/)  
        '************************************************************************* Xqp|VbDca  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) aYL|@R5;e  
        GetConic eID, entity, curv, conic I4rPHZ|  
    "`}~~.q  
        SetConic eID, entity, 1/Rpost, CCpost ^IZ)#1U  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Y**|N8e  
    z2ms^Y=j  
        '************************************************************************* \u`)kJ5o1  
        'Lens thickness (Position of posterior lens surface) t{!  
        '************************************************************************* W]<$0  
    -O:_!\uA  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) F}Mhs17!|  
    ~:;3uL s,8  
        ' Delete any z-shift(s) Hx^!:kxk  
        count = 0 0?7XtC P<  
        While GetOperationCount(eID)>count 7>o .0  
            GetOperation eID, count, op 3HG;!D~m;  
            If op.Type="ShiftZ" Then 0m[dP  
                DeleteOperation eID,count 1Wg-x0R  
                count=count-1 QrD o|GtE  
            End If S6nhvU:  
            count=count+1 Qx|H1_6  
        Wend *E>.)B i  
    ,reJ(s  
        'Set new z-shift oR+-+-? ?$  
        op.Type = "ShiftZ" :@ uIxa$[  
        op.val1 = tlens Dkw%`(Oh/,  
        op.parent = parID W@L3+4  
        AddOperation eID, op \jW)Xy  
        Print "Set lens thickness = " & tlens @ $cUNvI  
    H{ M)-  
        '************************************************************************* ux2013C_  
        'Lens index of refraction )yee2(S  
        '************************************************************************* Lrz3   
        eID = FindMaterial( "Lens" ) Lf}8qB#Y  
        GetModelMaterial eID, mat 7l8[xV  
    ;#?M)o:q  
        mat.Nd = nlens f*((;*n ;  
        SetModelMaterial eID, mat (ClhbfzD  
        Print "Set lens index of refraction = " & nlens s PYX~G&T  
    R zR?&J  
        '************************************************************************* 0Vv9BL{  
        'Pupil diameter oVkq2  
        '************************************************************************* _uH9XGm  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) tn<6:@T  
    GKtS6$1d#  
        'Adjust pupil diameter (trimming volume inner hole) _."E%|5  
    nnCug  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" pu;3nUH  
    M=!i>(yG  
        ' Adjust pupil location to just in front of the lens Ueyw;Y  
        parID = FindFullName( "Geometry.Arizona Eye" ) M-9gD[m  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 2hOPzv&B  
        count = 0 B!,yfTk]  
        While GetOperationCount(eID)>count b](o]O{v  
            GetOperation eID, count, op `| 9Ku  
            If op.Type="ShiftZ" Then Y(i?M~3\t  
                DeleteOperation eID,count SE`l(-tL  
                count=count-1 c?6d2jH.  
            End If xfHyC'?  
            count=count+1 iB bbr,  
        Wend [%8@D C'  
        op.Type = "ShiftZ" D s-`  
        op.val1 = taq-0.01 j7/(sf  
        op.parent = parID [&VxaJ("3  
        AddOperation eID, op n(&*kfk  
    +WF.wP?y  
        Print "Set pupil diameter = " & pupilDiam Npa-$N&P{S  
    ,IjdO(?TC  
        'Update AZ Eye subassembly Description h([0,:\  
        eID = FindFullName( "Geometry.Arizona Eye" ) &5q{viI  
        GetEntity eID, entity z\}!RBOq  
        entity.Description = "Accommodation = " & A & "D" f5?hnt`m  
        SetEntity eID, entity G[6=u|(M  
    yiT{+;g^  
        Update N(R,8GF5G  
        Print "DONE!" raQYn?[  
         k+\7B}7F  
    End Sub faVS2TN4  
    b\L)m (  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: tc/jY]'32  
    # U`&jBU  
    Accommodation = 4 Diopters n\~yX<;X3  
    Pupil Diameter = 4 mm GTFl}t  
    Set aqueous humor thickness = 2.81 jr1Se9u D  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 S ljZ~x,!  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 yHw!#gWM  
    Set lens thickness = 3.927 ~%GSsm\J  
    Set lens index of refraction = 1.42672 riEqW}{  
    Set pupil diameter = 4 3mA/Nu_  
    DONE! JOHp?3"4  
    0C7"3l  
    (文章来源:讯技光电)
     
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