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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 wu3p2#-Z  
    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。 IJBIO>Z/  
    GriFb]ml"  
    模型 Muok">#3.  
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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。 -o+; e3#  
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    Table 1. AZ眼睛模型的定义
    V1\Rj0#G  
    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. s} oD?h:T3  
    9:7&`J lC#  
    光源 Q+dLWFI  
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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_Uy.0=4  
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    图1. 光源和提示信息使用
    !JbWxGN`jn  
    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。 c"pu"t@/Z  
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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。 I~ e,']  
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    图2. 字母F光源的设定方法光 |b+CXEzo  
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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 HJ;!'@  
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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。 U<wM#l P|Z  
    +O@|bd \  
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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。 98lz2d/Fcq  
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    图5. 视网膜重点采样规格设定
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    脚本 KdC'#$  
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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: B[fbPrM  
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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。 z|O3pQn~  
    余下的脚本计算与屈光度有关的所有参数。 $8>II0C.  
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    分析 6@Ir|o  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 HH|N~pBJB  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 NB3ar&.$S  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. )jm!^m  
    =L*-2cE6#  
    Dim entity As T_ENTITY !nTI(--  
    Dim op As T_OPERATION \  `|  
    Dim mat As T_MODELMATERIAL U$LI~XZM  
    Dim A As Double 4f'!,Q ;  
    Dim pupilDiam As Double ~xf uq{L;  
    Dim eID As Long jz,Gj}3;  
    Dim parID As Long Pp`[E/ qj4  
    Dim count As Integer TsY nsLQY  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double $.3J1DU  
    Dim tlens As Double, nlens As Double dlBr2 9  
    Dim curv As Double, conic As Double co{i~['u  
    Dim ok As Long r}-vOPn`E  
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    Sub Main H Em XB=  
    ;nKhmcQ4  
        '用户输入对话框 p']{WLDj2  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 j9&x# U  
            TextBox 220,21,40,21,.TextBox1 'default: 0 u^( s0q  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 t(xe*xS  
            OKButton 40,91,90,21 Xr{ r&Rl  
            CancelButton 190,91,90,21 lF~!F<^9  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 s,-}}6WO  
            TextBox 220,49,40,21,.TextBox2 'default: 4 >Zh^,T={G  
        End Dialog B* k|NZj  
        Dim dlg As UserDialog lf_q6y  
    U _~r0  
        ok = Dialog (dlg) wQojmmQ  
     ](>YjE0  
        If ok=0 Then    'cancel button was pressed `: 9n ]xP  
            Print "Execution cancelled." Vn?|\3KY  
            End pd.5  
        End If aEdc8i ?  
    U9"Ij}  
        'Assign accommodation and pupil diameter & use defaults if field left empty Dw.Pv)'$  
        If dlg.TextBox1 = "" Then )|KZGr  
            A = 0           'Default accommodation fkD-mRKw  
        Else `h<>_zpjY  
            A = CDbl(dlg.TextBox1) LX m@h  
        End If cX|(/h,W/  
    c"zE  
        If dlg.TextBox2 = "" Then 7x.] 9J  
            pupilDiam = 4   'Default pupil diameter '3 JVUHn  
        Else @-.Tgpe@a  
            pupilDiam = CDbl(dlg.TextBox2) '%*/iH6<U{  
        End If D{^CJ :n  
    ;TboS-Y  
        Print " " 6<No_x |_  
        Print "Accommodation = " & A & " Diopters" Za7!n{? 0  
        Print "Pupil Diameter = " & pupilDiam & " mm"  !qTP  
    fDwqu.K  
        ' Calculate new parameters with accommodation RM#.-gW   
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness a#m T@l\  
    h&z(;B!;y.  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 6&,9=(:J&R  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens =r^Pu|  
    9Rb tFwbn  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens \{ff7_mLo  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens vUB*Qm]Y\  
    *OHaqe(*  
        tlens = 3.767 + 0.04*A                  'Lens thickness ,{BF`5bn|  
    a6hDw'8!  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction bP7_QYQ6  
    _A6e|(.ll  
        'Adjust parameters to account for accommodation 2E@g#:3  
    %QQJSake|  
        '************************************************************************* +7j7zpw  
        'Aqueous thickness (Position of Lens) c? >;UzM  
        '************************************************************************* )No>Q :t  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~2O1$ou  
        GetCustomElement eID, entity v[<;z(7Qk  
    z W*Z  
        parID = FindFullName( "Geometry.Arizona Eye" ) ef:YYt{|q  
    \6vr)1~N>  
        ' Delete any shift(s) in z N9=?IFEe]  
        count = 0 4AYW'j C  
        While GetOperationCount(eID)>count ~Q+J1S]Fs  
            GetOperation eID, count, op `$ZBIe/u  
            If op.Type="ShiftZ" Then eV(   
                DeleteOperation eID,count vd0uI#g%#  
                count=count-1 5N$O  
            End If Z!I#Z2X  
            count=count+1 \{a 64  
        Wend d ZxrIWx  
    hh<ryuZ  
        'Set new shift in #* Iyvx  
        op.Type = "ShiftZ" }W nvz;]B  
        op.val1 = taq 8W x7%@^O  
        op.parent = parID `bjPOA(g  
        AddOperation eID, op [wM]w  
        Print "Set aqueous humor thickness = " & taq-0.55 ;bkvdn}  
    lj@ ibA]  
        '************************************************************************* d1u6*&@lf  
        'Radius and conic constant of anterior lens =S|dzgS/  
        '************************************************************************* cR!Mn$m  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) |[MtUWEW  
        GetConic eID, entity, curv, conic {3K`yDF  
    $uYfy<  
        SetConic eID, entity, 1/Rant, CCant +H "j-:E@t  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant quiX "lV(  
    hGj`IAW  
        '************************************************************************* ^) 5*?8#  
        'Radius and conic constant of posterior lens <MgC7S2I  
        '************************************************************************* )\QPUdOvx  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 7X/KQ97  
        GetConic eID, entity, curv, conic D9higsN  
    ~iU@ns|g\  
        SetConic eID, entity, 1/Rpost, CCpost aThvq%;  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost @K}Bll.E  
    Frum@n  
        '************************************************************************* G(MLq"R6U  
        'Lens thickness (Position of posterior lens surface) !">EZX  
        '************************************************************************* W|V9:A  
    $DhW=(YM_a  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) i`7:^v;  
    ]ujXPK=t  
        ' Delete any z-shift(s) Lo5CVlK  
        count = 0 lh*!f$2 ~  
        While GetOperationCount(eID)>count Sv[$.^mb  
            GetOperation eID, count, op ]TSzT"_r~~  
            If op.Type="ShiftZ" Then 'rSJ9Mw"x  
                DeleteOperation eID,count Fqg*H1I[  
                count=count-1 mLH,6rO9  
            End If G!g];7PG(  
            count=count+1 {i/7Nx  
        Wend O*m9qF<  
    Z>J3DH  
        'Set new z-shift .pPtBqp  
        op.Type = "ShiftZ" 7 MG<!U  
        op.val1 = tlens iB3C.wd-  
        op.parent = parID !X+}W[Ic^  
        AddOperation eID, op /H :Bu  
        Print "Set lens thickness = " & tlens /9SNXjfbt  
    GLa_[9 "  
        '************************************************************************* 5 IFc"  
        'Lens index of refraction &f<Ltdw  
        '************************************************************************* osI0m7ws:  
        eID = FindMaterial( "Lens" ) X oh@(%  
        GetModelMaterial eID, mat ]vZ}4Xno  
    uF<\|y rFt  
        mat.Nd = nlens {/K!cPp9  
        SetModelMaterial eID, mat SI:Iv:>  
        Print "Set lens index of refraction = " & nlens >o! 5)\F  
    u~\ NL{  
        '************************************************************************* =[IKwmCX  
        'Pupil diameter `{'h+v`  
        '************************************************************************* |#x]/AXa0/  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 9[Xe|5?c  
    #gRtCoew  
        'Adjust pupil diameter (trimming volume inner hole) RgLkAHA  
    gutf[Ksu  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Ct386j><  
    4 |xQQv  
        ' Adjust pupil location to just in front of the lens X A-,  
        parID = FindFullName( "Geometry.Arizona Eye" ) (V# *}eGy  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) s Vg89I&  
        count = 0 9RJFj?^"  
        While GetOperationCount(eID)>count ;  8u5  
            GetOperation eID, count, op mZ4I}_\,  
            If op.Type="ShiftZ" Then 48[b1#q]  
                DeleteOperation eID,count VpWpC&  
                count=count-1 2[5z6oG  
            End If xQ\S!py-  
            count=count+1 og8"#%  
        Wend [OQ+&\  
        op.Type = "ShiftZ" bC%}1wwh  
        op.val1 = taq-0.01 GE |P)VO  
        op.parent = parID 1 eMaKT_=  
        AddOperation eID, op m9Hdg^L  
    A&=`?4>  
        Print "Set pupil diameter = " & pupilDiam <(B: "wI  
    QS2~}{v  
        'Update AZ Eye subassembly Description & 6~AY :0r  
        eID = FindFullName( "Geometry.Arizona Eye" ) 4zx_L8#Z  
        GetEntity eID, entity :1e'22[=.  
        entity.Description = "Accommodation = " & A & "D" 'kk B>g7B  
        SetEntity eID, entity l8By2{pN  
    J]qx4c  
        Update G?v]|wdI  
        Print "DONE!" 0xpE+GY  
         l5,}yTUta  
    End Sub T``~YoIdz  
    yNN_}9  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: <PXnR\  
    J)_IfbY  
    Accommodation = 4 Diopters 3k5F$wf  
    Pupil Diameter = 4 mm j8{,u6w)-  
    Set aqueous humor thickness = 2.81 6D1tRo  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 Q)l~?Fx  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 d> L*2 g  
    Set lens thickness = 3.927 2[yfo8H  
    Set lens index of refraction = 1.42672 )}5f'TK  
    Set pupil diameter = 4 <" F|K!Tz  
    DONE! 5=9gH  
    7wwlZ;w  
    (文章来源:讯技光电)
     
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