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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 )$x_!=@1  
    人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 ;,O fJ'q^  
    vs&8wbS)  
    模型 &GWkq>  
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    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 !Ngw\@f  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. R UTnc  
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    光源 J0220 _  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 l!IKUzt)7  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 7uI#L}y  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 PQj<[rY  
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    图2. 字母F光源的设定方法光 .gYt0raSY  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 0-2"FdeQU  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 -)w]a{F  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 ]HvZ$  
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    图5. 视网膜重点采样规格设定
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    脚本 C}CKnkMMD  
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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: R,Ml&4pZ}  
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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。 )mkS5j`5\  
    余下的脚本计算与屈光度有关的所有参数。 7U:=~7GH  
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    分析 zLek& 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。 8B@J Fpg^  
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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 &=-PRza%j  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. If.n(t[M9  
    :t2B^})\  
    Dim entity As T_ENTITY xv0M  
    Dim op As T_OPERATION $pFk"]=  
    Dim mat As T_MODELMATERIAL 'TX M{RGw  
    Dim A As Double YsAF{  
    Dim pupilDiam As Double %3,xaVN  
    Dim eID As Long K+mU_+KRp  
    Dim parID As Long @}eNV~ROu  
    Dim count As Integer G?[-cNdk  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]_2 yiKv&  
    Dim tlens As Double, nlens As Double 2X_>vIlEm  
    Dim curv As Double, conic As Double K^ 6+Ily  
    Dim ok As Long od,tfLw4  
    WEVl9]b'e+  
    Sub Main X')S;KW  
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        '用户输入对话框 2nx9#B*/T  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 46dc.Yi  
            TextBox 220,21,40,21,.TextBox1 'default: 0 l;5`0N?QO  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Mdky^;qq3;  
            OKButton 40,91,90,21 *8206[y  
            CancelButton 190,91,90,21 MF|*AB|E  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 KnFQ)sX^  
            TextBox 220,49,40,21,.TextBox2 'default: 4 A`C-sD >  
        End Dialog X2P``YFV{  
        Dim dlg As UserDialog kJeu40oN  
    ;KS`,<^-  
        ok = Dialog (dlg) Bbs5f@E  
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        If ok=0 Then    'cancel button was pressed cUC17z2D  
            Print "Execution cancelled." `]hCUaV   
            End X X&K=<,Ja  
        End If acP ;(t  
    "GLYyC  
        'Assign accommodation and pupil diameter & use defaults if field left empty }s6G!v^2""  
        If dlg.TextBox1 = "" Then u#VweXyU  
            A = 0           'Default accommodation r./z,4A`  
        Else Q;@X2 JSp  
            A = CDbl(dlg.TextBox1) ?.j,Bq5At  
        End If lrn+d$!@  
    J=V yyUB  
        If dlg.TextBox2 = "" Then Fd}<Uote3  
            pupilDiam = 4   'Default pupil diameter X?kPi&ru  
        Else :o<N!*pT  
            pupilDiam = CDbl(dlg.TextBox2) 1:YAn  
        End If [>wzl"cHW  
    s+N^PX3  
        Print " " &*ZC0V3  
        Print "Accommodation = " & A & " Diopters" RSFJu\0}N  
        Print "Pupil Diameter = " & pupilDiam & " mm" s79 q 5  
    2| $k`I,  
        ' Calculate new parameters with accommodation {N Y]L==H  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 8k%H[Smn:  
    "& Ff[ O*  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Lv^a+'  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 9Yd-m  
    R;.d/U|av  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 6_Fpca3L  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens +&?'KZ+Z_v  
    Kj=;>u  
        tlens = 3.767 + 0.04*A                  'Lens thickness 5(KG=EHj_  
    6l<1A$BQ  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction SUo^c1)G  
    =s6E/K  
        'Adjust parameters to account for accommodation y 'mlee  
    Gk{W:866  
        '************************************************************************* yX3PUO9  
        'Aqueous thickness (Position of Lens) 6,a%&1_  
        '************************************************************************* %OuX`w=  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) m^5s >hUl  
        GetCustomElement eID, entity _>;&-e  
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        parID = FindFullName( "Geometry.Arizona Eye" ) ,v|CombIc.  
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        ' Delete any shift(s) in z Bmmb  
        count = 0  JUmw$u  
        While GetOperationCount(eID)>count xa' nJ"f;  
            GetOperation eID, count, op H 'D#s;SlR  
            If op.Type="ShiftZ" Then `~0P[>|+  
                DeleteOperation eID,count pEY>A_F  
                count=count-1 +tPx0>p;  
            End If m\/>C|f\  
            count=count+1 P_v0))n{  
        Wend w< v1 N  
    <&KLo>B^  
        'Set new shift in qjJ{+Rz2  
        op.Type = "ShiftZ" u0wn=Dg  
        op.val1 = taq B<(Pd  
        op.parent = parID OuMco+C  
        AddOperation eID, op T4Xtuu1  
        Print "Set aqueous humor thickness = " & taq-0.55 Q%+ }  
    ZK%Kgk[\:~  
        '************************************************************************* U8EJC .e&O  
        'Radius and conic constant of anterior lens -*rHB&e  
        '************************************************************************* l t&$8jh  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) /A0 [_  
        GetConic eID, entity, curv, conic IkiQ Ok  
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        SetConic eID, entity, 1/Rant, CCant sg+ZQDF{x  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #,7eQaica  
    G`9cd\^  
        '************************************************************************* qPL^zM+  
        'Radius and conic constant of posterior lens #Tup]czO  
        '************************************************************************* 1 ,#{X3  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) E]e, cd  
        GetConic eID, entity, curv, conic GU:r vS!  
    )!'Fa_$ e  
        SetConic eID, entity, 1/Rpost, CCpost @47[vhE  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;r gH}r  
    A*G )CG  
        '************************************************************************* oNiToFbQu  
        'Lens thickness (Position of posterior lens surface) a v'd%LZP  
        '************************************************************************* zJz82jMm  
    A4~D#V  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) pESB Il  
    ;% /6Y~/  
        ' Delete any z-shift(s) IlcNT_ 5a8  
        count = 0 oq=?i%'>  
        While GetOperationCount(eID)>count P%.`c?olbs  
            GetOperation eID, count, op <QYCo1_  
            If op.Type="ShiftZ" Then omXBnzT  
                DeleteOperation eID,count *p""YEN  
                count=count-1 Y1$#KC  
            End If pe\Txg6  
            count=count+1 * i=?0M4S  
        Wend "z^BKb5  
    _F}IF9{?G  
        'Set new z-shift L4\SB O  
        op.Type = "ShiftZ" B rez&3[  
        op.val1 = tlens l9M#]*{  
        op.parent = parID "[%;B0J  
        AddOperation eID, op ${jA+L<J  
        Print "Set lens thickness = " & tlens @ChN_gd3!  
    ^Nd|+}  
        '************************************************************************* 7xLo 4  
        'Lens index of refraction se<i5JsSV  
        '************************************************************************* l-DGy#h+z  
        eID = FindMaterial( "Lens" ) )ZS:gD  
        GetModelMaterial eID, mat g i1}5DR  
    *%ed;>6:Q  
        mat.Nd = nlens ^2&O3s  
        SetModelMaterial eID, mat &*jxI[  
        Print "Set lens index of refraction = " & nlens 1?/5A|?V4+  
    &,m'sQ  
        '************************************************************************* IeR l6r%:  
        'Pupil diameter S(g<<Te  
        '************************************************************************* hN>('S-cq  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) H B::0l<  
    NZfo`iHAN  
        'Adjust pupil diameter (trimming volume inner hole) 3Ew"[FUs  
    xHM&csL  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 4f@havFIJ  
    C5:dO\?O  
        ' Adjust pupil location to just in front of the lens hW0,5>[7%  
        parID = FindFullName( "Geometry.Arizona Eye" ) ?#VP)A  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]ro1{wm!WU  
        count = 0 1A|x$j6m  
        While GetOperationCount(eID)>count e.3sAUHZ-  
            GetOperation eID, count, op "sX [p  
            If op.Type="ShiftZ" Then G/LXUhuif  
                DeleteOperation eID,count #Qtg\X  
                count=count-1 D{,[\^c  
            End If !7O=<  
            count=count+1 NPB,q& Th  
        Wend 9G`FY:(K  
        op.Type = "ShiftZ" OH-~  
        op.val1 = taq-0.01 s8f3i\1  
        op.parent = parID q5?rp|7D  
        AddOperation eID, op ^'C,WZt  
    %S(#cf!HP  
        Print "Set pupil diameter = " & pupilDiam \,@Yl.,+  
    9a"Y,1  
        'Update AZ Eye subassembly Description ;y?D1o^r8W  
        eID = FindFullName( "Geometry.Arizona Eye" ) [B2>*UPl  
        GetEntity eID, entity 4y]:Gq z~  
        entity.Description = "Accommodation = " & A & "D" g|GvJ)VX  
        SetEntity eID, entity w]o:c(x@  
    H}jK3;8E  
        Update ch)Ps2i  
        Print "DONE!" j(@g   
         5Gw!9{ke  
    End Sub v2Qc}o  
    B>p0FQ.  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: !SO$k%b}!  
    }<}`Q^Mlk  
    Accommodation = 4 Diopters RAv RNd  
    Pupil Diameter = 4 mm V(' 'p{  
    Set aqueous humor thickness = 2.81 Ads<-.R  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 :N+#4rtgUY  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 *Lb(urf  
    Set lens thickness = 3.927 |`)V^e_  
    Set lens index of refraction = 1.42672 n&3iv ^  
    Set pupil diameter = 4 'n>3`1E,  
    DONE! .qqb> 7|q  
    RIVL 0Ig  
    (文章来源:讯技光电)
     
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