切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 14303阅读
    • 0回复

    [转载]FRED运用:Arizona眼睛模型 [复制链接]

    上一主题 下一主题
    离线xunjigd
     
    发帖
    952
    光币
    9
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2016-02-24
    简介 n,eO6X 4  
    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。 uQ4WM  
    a}l^+  
    模型 &f1dCL%z7  
    d, j"8\@  
    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。 D.G+*h@ g  
    MrIo.  
    Table 1. AZ眼睛模型的定义
    AtNu:U$  
    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^}gQow  
    xmz83Ll9  
    光源 Yv!%Is  
    !( xeDX  
    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。 >U@7xeK  
    ^` N+mlh  
    n m4+$GW   
    图1. 光源和提示信息使用
    56(S[  
    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 z38&7+  
    SEm3T4dfzf  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 Ct[{>asun  
    09y%FzV  
    图2. 字母F光源的设定方法光 <TmMUA)`}  
    ws:@Pe4AF  
    图3. 字母F在视网膜上位置点列图
    _uL{@(  
    视网膜的散射 wPTXRq%  
    )&[S*g  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 -~Kw~RX<(  
    .L'>1H]B  
    {f] K3V  
    图4. 视网膜朗伯散射设定
    Q jMH1S  
    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 l0Wp%T  
    &i*/}OZz  
    w4Nm4To  
    图5. 视网膜重点采样规格设定
    M{$EJS\d=  
    脚本 ]8*#%^  
    4[t1"s~Wg  
    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: 1au1DvH  
    ^`NU:"  
    图6. 用户对话框的创建与编辑
    `Y `Ujr\6  
    图7. 用户对话框编辑器
    _W]qV2j  
    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。  6jFc'  
    余下的脚本计算与屈光度有关的所有参数。 6?n AO  
    *9((X,v@/  
    分析 x_lCagRGC4  
    zk8 s?$  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 VH1PC  
    -d? 9Acd  
    图7. 字母F在视网膜上颜色分析
    h?[3{Z^  
    脚本代码 hmJ{'D1"  
    xj~ /C5@  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 24Lo .  
    T% J;~|  
    Dim entity As T_ENTITY iD=VNf  
    Dim op As T_OPERATION ;pu68N(B  
    Dim mat As T_MODELMATERIAL ZaQg SE>Y  
    Dim A As Double INZycNqm,  
    Dim pupilDiam As Double k@nx+fO}P  
    Dim eID As Long FHWzwi*u}  
    Dim parID As Long *het_;)+{  
    Dim count As Integer 7r,'a{Rcn  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8:hUj>q x  
    Dim tlens As Double, nlens As Double Htn'(Q  
    Dim curv As Double, conic As Double NQzpgf|h  
    Dim ok As Long uKF?UXc  
    ,Oojh;P_  
    Sub Main =~Oi:+L  
    BH _y0[y  
        '用户输入对话框 e R"XXF0u  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Q7oJ4rIP  
            TextBox 220,21,40,21,.TextBox1 'default: 0 @cNBY7=  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 cbvK;;  
            OKButton 40,91,90,21 7Yp;B:5@  
            CancelButton 190,91,90,21 't".~H_V  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9 ! [oJ3  
            TextBox 220,49,40,21,.TextBox2 'default: 4 w5,p9f}.  
        End Dialog .),%S}  
        Dim dlg As UserDialog \,jrug<C$^  
    EacqQFErl  
        ok = Dialog (dlg) g _fvbVX  
    C 9IKX  
        If ok=0 Then    'cancel button was pressed 1{\{'EP{  
            Print "Execution cancelled." b5u_x_us|  
            End x9}D2Ui  
        End If OH~X~n-Z  
    .sNUU 3xSC  
        'Assign accommodation and pupil diameter & use defaults if field left empty 1;E[Ml  
        If dlg.TextBox1 = "" Then R=ddQ:W6g  
            A = 0           'Default accommodation g;)xf?A9q  
        Else {6Tw+/`P  
            A = CDbl(dlg.TextBox1) j3 d=O!  
        End If M,1Yce%+}  
    2Wz/s 0`  
        If dlg.TextBox2 = "" Then R:S Fj!W1  
            pupilDiam = 4   'Default pupil diameter #W`>vd}  
        Else `F<)6fk  
            pupilDiam = CDbl(dlg.TextBox2) .m_yx{FZ=  
        End If Qo+_:N  
    )%p.v P'p  
        Print " " "-JJ6Bk  
        Print "Accommodation = " & A & " Diopters" :_v/a+\n  
        Print "Pupil Diameter = " & pupilDiam & " mm" 3f9J! B`n  
    zRtaO'G(  
        ' Calculate new parameters with accommodation -Si'[5@  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ^luAX }*  
    sOA!Sl  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens v|acKux=t  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens `[\*1GpAo  
    WHxq-&=  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens  Qj(q)!Ku  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Q: ?]:i/*  
    t{t*.{w  
        tlens = 3.767 + 0.04*A                  'Lens thickness %v=z|d5-3  
    `?VtB!p@x=  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction oeKI9p13\  
    q,-bw2   
        'Adjust parameters to account for accommodation g2%&/zq/  
    $(v1q[ig  
        '************************************************************************* ]$/TsN  
        'Aqueous thickness (Position of Lens) 7M#2Tze}  
        '************************************************************************* [G:wPp.y  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) K~**. NF-n  
        GetCustomElement eID, entity )f]E<*k'E  
    *IWO ,!  
        parID = FindFullName( "Geometry.Arizona Eye" ) 3Gi#WV4$  
    prE~GO7Z  
        ' Delete any shift(s) in z V D+TJ` r  
        count = 0 8v)pPJr  
        While GetOperationCount(eID)>count K FV&Dt}<  
            GetOperation eID, count, op +@D [%l|  
            If op.Type="ShiftZ" Then g(xuA^~J  
                DeleteOperation eID,count [FLRrTcE  
                count=count-1 "l~wzPY)  
            End If , Zs:e.  
            count=count+1 _YzItge*  
        Wend Unev[!  
    nTO,d$!Kp  
        'Set new shift in 9`4mvK/@  
        op.Type = "ShiftZ" b['Jr% "O  
        op.val1 = taq B0I(/ 7  
        op.parent = parID Lf_`8Ux  
        AddOperation eID, op t4)~A5s  
        Print "Set aqueous humor thickness = " & taq-0.55 mKY}+21!Q  
    @czNiWU"4;  
        '************************************************************************* HNN,1MN  
        'Radius and conic constant of anterior lens ^n#6CW*n  
        '************************************************************************* {8D`A;KD  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) M@@l>"g@  
        GetConic eID, entity, curv, conic N{v <z 6  
    mk?&`_X1  
        SetConic eID, entity, 1/Rant, CCant 4Z>KrFO  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {J3;4p-&  
    bqpy@WiI S  
        '************************************************************************* u50 o1^<X  
        'Radius and conic constant of posterior lens c6gRXp'ID  
        '************************************************************************* 9%aBW7@SK  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) B-`d7c5  
        GetConic eID, entity, curv, conic & Ji!*~sE  
    d`9% :2qE  
        SetConic eID, entity, 1/Rpost, CCpost @,0W(  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost CDcZ6.f  
    n'a=@/  
        '************************************************************************* ^(7<L<H  
        'Lens thickness (Position of posterior lens surface) @ht= (Jk9  
        '************************************************************************* T+p ?VngF  
    urmx})=  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) \zioIfHm  
    b^b@W^\hn  
        ' Delete any z-shift(s) #DjSS.iW  
        count = 0 [5>f{L!<T<  
        While GetOperationCount(eID)>count rhU]b $A  
            GetOperation eID, count, op Vg9n b  
            If op.Type="ShiftZ" Then Htd-E^/  
                DeleteOperation eID,count kBZnR$Cl  
                count=count-1 z0[_5Cm/  
            End If UMsJg7~  
            count=count+1 jA@jsv  
        Wend .Fo0AjL}x  
    RGd@3OjN  
        'Set new z-shift 'J(rIH3U  
        op.Type = "ShiftZ" TtA6N8G  
        op.val1 = tlens r|2Y|6@  
        op.parent = parID . 7WNd/WG  
        AddOperation eID, op #~]S  
        Print "Set lens thickness = " & tlens "w3#2q&  
    Wj0=cIb  
        '************************************************************************* ?K9&ye_rgw  
        'Lens index of refraction eZpyDw C{  
        '************************************************************************* B3 fKb#T  
        eID = FindMaterial( "Lens" ) ,z A9*  
        GetModelMaterial eID, mat ._2#89V  
    #6O<!{PH6  
        mat.Nd = nlens UYJMW S=  
        SetModelMaterial eID, mat .f)&;Af^  
        Print "Set lens index of refraction = " & nlens t"[ xx_i  
    rN0G|  
        '************************************************************************* nT.i|(xd.  
        'Pupil diameter LLp/ SWe  
        '************************************************************************* i*-[-hn-V  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;MH((M/AN  
    hKa<9>MI`  
        'Adjust pupil diameter (trimming volume inner hole) Mrpz(})  
    6lW\-h`N G  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" h"h3SD~  
    PuyJ:#a  
        ' Adjust pupil location to just in front of the lens |C;8GSw>|F  
        parID = FindFullName( "Geometry.Arizona Eye" ) !h\.w9o[  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) byALM  
        count = 0 1Pya\To,m  
        While GetOperationCount(eID)>count kg0X2^#b  
            GetOperation eID, count, op Sg#$ B#g  
            If op.Type="ShiftZ" Then OP:i;%@c  
                DeleteOperation eID,count p5RnFe l  
                count=count-1 -*`7Q'}%  
            End If / =]h@m-`  
            count=count+1  AT@m_d  
        Wend $;GH -+  
        op.Type = "ShiftZ" |qUi9#NUo  
        op.val1 = taq-0.01 wm1`<r^M.  
        op.parent = parID Y~ku?/"6T  
        AddOperation eID, op ]O}TK^%  
    M8_f{|!&  
        Print "Set pupil diameter = " & pupilDiam {J#SpG 7  
    T'VZ=l[  
        'Update AZ Eye subassembly Description $7J9Yzp?L  
        eID = FindFullName( "Geometry.Arizona Eye" ) G;RFY!o  
        GetEntity eID, entity =rL%P~0wq  
        entity.Description = "Accommodation = " & A & "D" <Wd#HKIG>l  
        SetEntity eID, entity 8PKUg "p  
    1f 3c3PJ  
        Update c5 ^CWk K  
        Print "DONE!" ^/'zU,  
         Jd]kg,/  
    End Sub f\p#3IwwH  
    OKW}8qM  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: > nHaMj  
    TH[xSg  
    Accommodation = 4 Diopters zx #HyO[a  
    Pupil Diameter = 4 mm exW|c~|m{A  
    Set aqueous humor thickness = 2.81 G_ -8*.  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 CG[2  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 gc<w nm|  
    Set lens thickness = 3.927 <8J_[ S  
    Set lens index of refraction = 1.42672 HB|R1<t;HB  
    Set pupil diameter = 4 y$Nqw9  
    DONE!  _'Jz+f.  
    MUQj7.rNa  
    (文章来源:讯技光电)
     
    分享到