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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(9%SP@[c  
    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。 Gh}sk-Xk=  
    TbbtD"b?  
    模型 e2CjZ"C  
    F+ qRC_C>O  
    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。 #8iRWm0*6  
     "_t2R &A  
    Table 1. AZ眼睛模型的定义
    u^T)4~(  
    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. '1{co/Y  
    xU+c?OLi  
    光源 4%>iIPXi.(  
    (4=NKtA^G  
    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。 ua[ d  
    p'z fo!  
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    图1. 光源和提示信息使用
    $\?BAkx  
    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 3* C9;Q}  
    c+$alw L~  
    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。 ?CIMez(h  
    h}r64<Y2{  
    图2. 字母F光源的设定方法光 s)X'PJ0&Bs  
    a<-NB9o~v  
    图3. 字母F在视网膜上位置点列图
    w&<-pIa`  
    视网膜的散射 MebL Y $&8  
    #AHX{<  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 #vCtH2  
    veX#K#  
    tmEF7e`(o  
    图4. 视网膜朗伯散射设定
    L5$r<t<  
    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。 TpXbJ]o9  
    uj#bK 7  
    :k9n 9  
    图5. 视网膜重点采样规格设定
    [yj-4v%u`  
    脚本 VBV y3fnj  
    .: gZ*ks~  
    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: 6$]@}O^V  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
    ^1y (N>W  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 w5zr Ek#  
    余下的脚本计算与屈光度有关的所有参数。 d$.t0-lC  
    :uwB)G  
    分析 }4G/x;D  
    #mu3`,9V  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 :f<:>"<  
    RMJq9a  
    图7. 字母F在视网膜上颜色分析
    o"h* @.  
    脚本代码 :: IAXGH)  
    _Q&O#f  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. cb|cYCo5  
    *$+k-BV  
    Dim entity As T_ENTITY UC&f  
    Dim op As T_OPERATION  %T9'dcM  
    Dim mat As T_MODELMATERIAL IJX75hE0g  
    Dim A As Double G-FeDP  
    Dim pupilDiam As Double MP"Pqt  
    Dim eID As Long {[B^~Y>Lr  
    Dim parID As Long ?+6w8j%\  
    Dim count As Integer c*F'x-TH  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double |ci1P[y  
    Dim tlens As Double, nlens As Double #a7 Wx}  
    Dim curv As Double, conic As Double , c3gW2E  
    Dim ok As Long /;P* ?  
    EPO*{bN7O  
    Sub Main }t.J;(ff:  
    gZkjh{rQ  
        '用户输入对话框 _g{*;?mS  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 QN!.~>  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Th"0Cc)  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 yxv]G6  
            OKButton 40,91,90,21 kC : pal  
            CancelButton 190,91,90,21 4q%hn3\  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 2AN6(k4o  
            TextBox 220,49,40,21,.TextBox2 'default: 4 kFCjko  
        End Dialog @log=^  
        Dim dlg As UserDialog #fT1\1[]  
    8&d s  
        ok = Dialog (dlg) B^8]quOH  
    -TL `nGF  
        If ok=0 Then    'cancel button was pressed NR98I7  
            Print "Execution cancelled." UC@ &! kM  
            End TF0DQP  
        End If LHy-y%?i  
    2VSs#z!  
        'Assign accommodation and pupil diameter & use defaults if field left empty PH,MZ"Z%  
        If dlg.TextBox1 = "" Then /%O+]#$`0  
            A = 0           'Default accommodation \TchRSe  
        Else F|Y}X|x8Q  
            A = CDbl(dlg.TextBox1) u+ wKs`   
        End If D)0pm?*5A  
    :i{$p00 G  
        If dlg.TextBox2 = "" Then |q0MM^%"  
            pupilDiam = 4   'Default pupil diameter Ojea~Y]Sr  
        Else }Z^r<-N  
            pupilDiam = CDbl(dlg.TextBox2) M mihWD02  
        End If P1 \:hh  
    *^h$%<QI  
        Print " " W.nQYH  
        Print "Accommodation = " & A & " Diopters" Z.!tp  
        Print "Pupil Diameter = " & pupilDiam & " mm" %+>t @F,GM  
    6LVJ*sjSy  
        ' Calculate new parameters with accommodation <OYy ;s  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness WnATgY t  
    IdY\_@$ v  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens B Q) 1)8r  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens :#yjg1aej  
    y[L7=Td  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens _dg2i|yP<  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 7&I+mw/X  
    (YOp  
        tlens = 3.767 + 0.04*A                  'Lens thickness jg,oGtRz  
    ,7wxVR%Ys  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction J~\`8cds  
    d-cK`pSB  
        'Adjust parameters to account for accommodation ,F4 _ps?(  
    OfSy_#aEK  
        '************************************************************************* x37pj)i/  
        'Aqueous thickness (Position of Lens) /Ah|Po  
        '************************************************************************* d{~5tv- H  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) @(;zU~l/  
        GetCustomElement eID, entity 'yrU_k,h  
    Dg:2*m_!j{  
        parID = FindFullName( "Geometry.Arizona Eye" ) ;p$KM-?2D  
    #gHs!b-g@  
        ' Delete any shift(s) in z  xr }jw  
        count = 0 Jl,mYFEZ  
        While GetOperationCount(eID)>count !'ylh8}  
            GetOperation eID, count, op hM": ?Rx  
            If op.Type="ShiftZ" Then #fF~6wopV  
                DeleteOperation eID,count ^5"2s:vP  
                count=count-1 Y<A593  
            End If ^CZ)!3qd1  
            count=count+1 l7g< $3  
        Wend :tc]@0+  
    f]P&>j|  
        'Set new shift in xj1FCT2  
        op.Type = "ShiftZ" AqD)2O{VO  
        op.val1 = taq RsY7F;  
        op.parent = parID |'C {nTX  
        AddOperation eID, op Pf?*bI  
        Print "Set aqueous humor thickness = " & taq-0.55 %J_`-\)"{~  
    'dnTu@mUT  
        '************************************************************************* (l|:$%[0  
        'Radius and conic constant of anterior lens ("UzMr,  
        '************************************************************************* T'n~Qf U  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) x B%Felz  
        GetConic eID, entity, curv, conic n+C,v.X  
    JZCRu_M>|  
        SetConic eID, entity, 1/Rant, CCant sQBl9E'!be  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant k"J [mT$b  
    p6qza @  
        '************************************************************************* hQm"K~SW=  
        'Radius and conic constant of posterior lens aNqhxvwf  
        '************************************************************************* >bKN$,Qen  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) }~Am{Er <l  
        GetConic eID, entity, curv, conic U[!x 0M  
    D@M ZTb  
        SetConic eID, entity, 1/Rpost, CCpost JWu^7}@~=  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [Rqv49n*V  
    3#d5.Ut  
        '************************************************************************* z}Qt6na]-  
        'Lens thickness (Position of posterior lens surface) ;NyX9&@  
        '************************************************************************* {V> >a  
    WVP^C71  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^,Paih 2  
    ?A[q/n:K  
        ' Delete any z-shift(s) S 1%/ee3  
        count = 0 S{ v [65  
        While GetOperationCount(eID)>count i.0}d5Y  
            GetOperation eID, count, op N8<Wm>GLX~  
            If op.Type="ShiftZ" Then t)y WQV  
                DeleteOperation eID,count L_>j SP  
                count=count-1 sknta 0^=2  
            End If ^|z  
            count=count+1 SA5 g~{"  
        Wend p8%/T>hK  
    ZDmBuf q  
        'Set new z-shift :{iS0qJ  
        op.Type = "ShiftZ" X[ERlw1q4Q  
        op.val1 = tlens i+ I%]  
        op.parent = parID `iX~cUQ  
        AddOperation eID, op c,$ >u,4  
        Print "Set lens thickness = " & tlens ~w<u!  
    [SluYmW  
        '************************************************************************* KL2#Bm_  
        'Lens index of refraction .A: #l?  
        '************************************************************************* y4aW8J#  
        eID = FindMaterial( "Lens" ) !nQ!J+ g  
        GetModelMaterial eID, mat x Z 3b)j2D  
    cx]&ae*  
        mat.Nd = nlens &cty&(2p  
        SetModelMaterial eID, mat ZH9sf~7  
        Print "Set lens index of refraction = " & nlens Q4gsOx P  
    hOI| #(-  
        '************************************************************************* &ukYTDM  
        'Pupil diameter H /E.R[\+x  
        '************************************************************************* L-7?:  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =.@{ uu;  
    ogt<vng  
        'Adjust pupil diameter (trimming volume inner hole) 8pc=Oor2Tv  
     !,rp|  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" xWY%-CWY.  
    ;\N{z6  
        ' Adjust pupil location to just in front of the lens D^(Nijl9U  
        parID = FindFullName( "Geometry.Arizona Eye" ) }L.xt88  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) B~/:["zTh&  
        count = 0 beLT4~Z=  
        While GetOperationCount(eID)>count :iWW2fY  
            GetOperation eID, count, op dgLE/r?  
            If op.Type="ShiftZ" Then +tbG^w %  
                DeleteOperation eID,count w1Z9@*C!  
                count=count-1 qpo3b7(N  
            End If 2}Ga   
            count=count+1 aCu 8 D!  
        Wend K{eq'F5M  
        op.Type = "ShiftZ" Ga5O&`h  
        op.val1 = taq-0.01 IMaa#8,  
        op.parent = parID <cQ)*~hN  
        AddOperation eID, op ` XAlzI  
    3P{ d~2  
        Print "Set pupil diameter = " & pupilDiam D4e*Wwk  
    W\JbX<mQ  
        'Update AZ Eye subassembly Description LvlVZjT  
        eID = FindFullName( "Geometry.Arizona Eye" ) 9#K,@X5 j  
        GetEntity eID, entity [LDV*79Z  
        entity.Description = "Accommodation = " & A & "D" jQ &$5&o  
        SetEntity eID, entity `)sC".b7  
    *v+xKy#M  
        Update AE1EZ#  
        Print "DONE!" RR,gC"cTi  
         #r\,oXTm  
    End Sub Ns?8N":  
    ^Ht!~So  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: Gqe?CM  
    c{YBCWA  
    Accommodation = 4 Diopters ^gP pmb<x  
    Pupil Diameter = 4 mm Y?cdm}:Ou  
    Set aqueous humor thickness = 2.81 ~Z74e>V%  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 %,HuG-L  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 I[mlQmwsL.  
    Set lens thickness = 3.927 p.(8ekh  
    Set lens index of refraction = 1.42672 y|sU-O2}Dl  
    Set pupil diameter = 4 Q\WH2CK  
    DONE! 4/6?wX  
    :bJT2o[  
    (文章来源:讯技光电)
     
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