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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 SYgkYR  
    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。 mwF{z.t"  
    f~f)6XU|  
    模型 AzSmfEaU0  
    ?p>m ;Aq  
    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。 c(s: f@ 1  
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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. h<g2aL21?F  
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    光源 M|UCV_omN  
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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。 R vd'uIJ  
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    图1. 光源和提示信息使用
    QGnUPiD^  
    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。 {^R>H|~  
    I-W ,C &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。 {wf5HA  
    <}}u'5;^?x  
    图2. 字母F光源的设定方法光 HHT8_c'CC#  
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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 )~ ^`[`  
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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。 ]#W9l\  
    $NBQv6#:  
     CxrsP.  
    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 V%voe  
    3.h0  
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    图5. 视网膜重点采样规格设定
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    脚本 %kuUQ%W1  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: 2|${2u`$&y  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
    9T<k|b[6  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 pV$A?b"?*  
    余下的脚本计算与屈光度有关的所有参数。 RG_6& A  
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    分析 Z OqD.=O(  
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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({-&A.N  
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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 yp< )v(8|'  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ;7(vqm<V2~  
    [=>[2Ty  
    Dim entity As T_ENTITY UGP&&A#T-  
    Dim op As T_OPERATION 07>D G#  
    Dim mat As T_MODELMATERIAL "j=E8Dd}  
    Dim A As Double CT (HTu  
    Dim pupilDiam As Double |wyua@2  
    Dim eID As Long w^[:wzF0  
    Dim parID As Long sc z8 `%  
    Dim count As Integer A%~t[ H  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5qkyi]/U8  
    Dim tlens As Double, nlens As Double *nwH1FjH  
    Dim curv As Double, conic As Double gj82qy\:  
    Dim ok As Long ;6`7 \  
    nQG<OVRClS  
    Sub Main a@#<qf8g  
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        '用户输入对话框 f+2mX"Z[F  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ~l*[=0}  
            TextBox 220,21,40,21,.TextBox1 'default: 0 r|ogF8YN  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 5[P^O6'  
            OKButton 40,91,90,21 h@Ix9!?+  
            CancelButton 190,91,90,21 Or-LQ^~  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 AA}+37@2I  
            TextBox 220,49,40,21,.TextBox2 'default: 4 X|y0pH:S  
        End Dialog _$KkSMA~_  
        Dim dlg As UserDialog ZpZoOdjslV  
    iN2591S  
        ok = Dialog (dlg) x #t?`  
    (mx}6A  
        If ok=0 Then    'cancel button was pressed )9+H[  
            Print "Execution cancelled." +B4i,]lCx  
            End T^Hq 5Oy  
        End If 0kaMYV?  
    3vEwui-5  
        'Assign accommodation and pupil diameter & use defaults if field left empty 4r9AUmJqw  
        If dlg.TextBox1 = "" Then ngzQVaB9  
            A = 0           'Default accommodation `-5gsJ  
        Else ~jJe|zg>  
            A = CDbl(dlg.TextBox1) 0VIR =Pbp  
        End If tNxKpA |F  
    TtgsM}Fm  
        If dlg.TextBox2 = "" Then ;s5JYR  
            pupilDiam = 4   'Default pupil diameter f_IsY+@  
        Else h-\+# .YP  
            pupilDiam = CDbl(dlg.TextBox2) D+7[2$:z  
        End If hjp,v)#  
    wLo<gA6;  
        Print " " vh^?M#\  
        Print "Accommodation = " & A & " Diopters" x'V:qv*O  
        Print "Pupil Diameter = " & pupilDiam & " mm" Jv~^hN2  
    >FL%H=]  
        ' Calculate new parameters with accommodation !)FKF7'  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 2D"aAI<P  
    ephvvj~zW4  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ` bZgw  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens (1%A@ 4  
    HcHwvf6y  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens  r^,"OM]  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens JC7:0A^  
    8B6 -f:  
        tlens = 3.767 + 0.04*A                  'Lens thickness ?qbq\t  
    *Q;?p hr  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 2QKt.a  
    l2kUa'O-  
        'Adjust parameters to account for accommodation | zOwC9-6  
    `|4k>5k  
        '************************************************************************* 6e"Lod_ L  
        'Aqueous thickness (Position of Lens) (ZQ?1Qxo  
        '************************************************************************* iO}KERfU  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Uq.hCb`:  
        GetCustomElement eID, entity VhU,("&pm  
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        parID = FindFullName( "Geometry.Arizona Eye" ) seZb;0  
    ^(7Qz&q  
        ' Delete any shift(s) in z Zl?9ibm;@  
        count = 0 !'a <Dw5  
        While GetOperationCount(eID)>count ym2"D?P (  
            GetOperation eID, count, op 0Q[;{}W}  
            If op.Type="ShiftZ" Then ]qiX"<s>~C  
                DeleteOperation eID,count i~rb-~o  
                count=count-1 p+${_w>pl{  
            End If gN[^ ,u  
            count=count+1 >*$Xbj*  
        Wend p,7?rI\N  
    V2$M`|E  
        'Set new shift in WLCr~r^  
        op.Type = "ShiftZ" G'{&*]Z\:  
        op.val1 = taq 4TSkm`iR  
        op.parent = parID DDZnNSo<JQ  
        AddOperation eID, op l6.&<0pLT  
        Print "Set aqueous humor thickness = " & taq-0.55 ,vuC0{C^  
    UtHloq(r  
        '************************************************************************* >C`#4e?}  
        'Radius and conic constant of anterior lens x::d}PP7  
        '************************************************************************* gq~"Z[T  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) v(P <_}G  
        GetConic eID, entity, curv, conic _Zxo <}w}y  
    }Zfi/^0U  
        SetConic eID, entity, 1/Rant, CCant *O7PH1G  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 'Qg.D88  
    ?h,.1Tb  
        '************************************************************************* -:Bgp*S  
        'Radius and conic constant of posterior lens d"thM  
        '************************************************************************* j? Vs"d|  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 9G4os!x)  
        GetConic eID, entity, curv, conic IaO*{1re  
    WnA Y<hZ|  
        SetConic eID, entity, 1/Rpost, CCpost Yh{5O3(;  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost M*aYcIU((  
    w7f)v\p  
        '************************************************************************* dcfwUjp[  
        'Lens thickness (Position of posterior lens surface) N[N4!k )!$  
        '************************************************************************* :bXTV?#0  
    nIqF:6/  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) [C@ Ro,mI  
    HstL'{&,-m  
        ' Delete any z-shift(s) GK#D R/OM  
        count = 0 -jVg {f!  
        While GetOperationCount(eID)>count 38%"#T3#  
            GetOperation eID, count, op n2Q ?sV;m  
            If op.Type="ShiftZ" Then Bk5ft4v-  
                DeleteOperation eID,count upFe{M@  
                count=count-1 \!*F:v0g^  
            End If ,_K:DSiB  
            count=count+1 zbfe=J4c  
        Wend \\35} 9  
    /bmkt@$-0  
        'Set new z-shift }d@;]cps  
        op.Type = "ShiftZ" ri4:w_/{,Y  
        op.val1 = tlens OXZx!h  
        op.parent = parID #hXuGBZEI  
        AddOperation eID, op M{p9b E[j  
        Print "Set lens thickness = " & tlens ;HiaX<O!  
    r>G||/Z  
        '************************************************************************* BL%3[JQ  
        'Lens index of refraction zR?1iV.]  
        '*************************************************************************  _w FK+>  
        eID = FindMaterial( "Lens" ) >E WK cocM  
        GetModelMaterial eID, mat ${`q!  
    7<k@{xI/  
        mat.Nd = nlens Yx](3w ID  
        SetModelMaterial eID, mat eQIS`T  
        Print "Set lens index of refraction = " & nlens [5Zi\'~UH)  
    kqGydGh*"  
        '************************************************************************* 0\+$j5;  
        'Pupil diameter A@reIt  
        '************************************************************************* _,w*Rv5=  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ozA%u,\7k  
    !k#N] 9D3  
        'Adjust pupil diameter (trimming volume inner hole) }{v0}-~@  
    Z 2lX^z  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ^b*ub(5Ot  
    nyOvB#f  
        ' Adjust pupil location to just in front of the lens m3|l-[!OA"  
        parID = FindFullName( "Geometry.Arizona Eye" ) HN<e)E38  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ~!_UDD  
        count = 0 .[Ny(X/]/}  
        While GetOperationCount(eID)>count <<H'Z  
            GetOperation eID, count, op <lWBhrz  
            If op.Type="ShiftZ" Then '@"A{mrE  
                DeleteOperation eID,count fmFs  
                count=count-1 h9 rrkV9  
            End If M* dou_Q  
            count=count+1 9W j9=  
        Wend Sf t,$  
        op.Type = "ShiftZ" (AHTv8  
        op.val1 = taq-0.01 uFaT~ 4  
        op.parent = parID l!IN#|{(  
        AddOperation eID, op P+,YWp  
    nDNK}O~'  
        Print "Set pupil diameter = " & pupilDiam >,f5 5  
    e(9K.3 @{  
        'Update AZ Eye subassembly Description G ahY+$L,  
        eID = FindFullName( "Geometry.Arizona Eye" ) q4Y'yp`?K;  
        GetEntity eID, entity $-gRD|oY  
        entity.Description = "Accommodation = " & A & "D" ?y^ ix+ M  
        SetEntity eID, entity 7Q aZ|\c  
    z@2nre  
        Update ;\iu*1>Z,&  
        Print "DONE!"  8vUq8[[  
         &p=(0$0&-  
    End Sub :oJ!9\5  
    bW zUWLa  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ShOB"J-  
    o|V=3y Ok  
    Accommodation = 4 Diopters ; $UB@)7%  
    Pupil Diameter = 4 mm {tnhP^C3>  
    Set aqueous humor thickness = 2.81 Rtai?  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 mm N $\2  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 +b{tk=Q:  
    Set lens thickness = 3.927 `>`{DEDx{5  
    Set lens index of refraction = 1.42672 5NMju!/  
    Set pupil diameter = 4 "mcuF]7F  
    DONE! d^`n/"Ice  
    xic&m5j m  
    (文章来源:讯技光电)
     
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