切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 14297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 jOT/|k  
    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。 \d;)U4__!  
    ]r#b:W\  
    模型 x'0_lf</ #  
    >/74u/&  
    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。 ho$}#o  
    9 C)VW  
    Table 1. AZ眼睛模型的定义
    @2T8H  
    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. 6hj[/O)E  
    CJk"yW[,|  
    光源 (-$5YKm  
    B>1,I'/$.  
    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。 ?;o0~][!  
    LBq2({="  
    @Y`Z3LiR$  
    图1. 光源和提示信息使用
    R]yce2w"z  
    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。 S(CkA\[rz  
    &Y^4>y%  
    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。 v@]SddP,?  
    ' ds2\gN  
    图2. 字母F光源的设定方法光 1qR$ Yr\  
    %~:\f#6  
    图3. 字母F在视网膜上位置点列图
    j5DCc,s  
    视网膜的散射 hY!ek;/Gc  
    4AzDWK@/  
    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。 iT:i '\~  
    4!Radl3`  
    +EjXoW7V  
    图4. 视网膜朗伯散射设定
    x"sbm  
    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。 w2xD1oK~o  
    ^~N:lW#=  
    c BqbbZyUk  
    图5. 视网膜重点采样规格设定
    cWo>DuW&  
    脚本 qqo#H O  
    mxZ+r#|di  
    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:  omg#[  
    lusUmFm'*  
    图6. 用户对话框的创建与编辑
    kSiyMDY-  
    图7. 用户对话框编辑器
    OIj.K@Kr  
    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。 C9?mxa*z  
    余下的脚本计算与屈光度有关的所有参数。 I'BHNZO5tf  
    %\HE1d5;  
    分析 ilQ}{p6I  
    L4B/ g)K  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 .`~?w+ ~  
    cY5;~lO  
    图7. 字母F在视网膜上颜色分析
    QxG^oxU}  
    脚本代码 I4%kYp]  
    EpO2%|@  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. b>QdP$>  
    OqS!y( (  
    Dim entity As T_ENTITY 2]?=\_T  
    Dim op As T_OPERATION QY4;qA  
    Dim mat As T_MODELMATERIAL qE2VUEv5Y  
    Dim A As Double \"$P :Uv  
    Dim pupilDiam As Double bK!h{Rr  
    Dim eID As Long .'A1Eoo0d  
    Dim parID As Long 5qH*"i+|s  
    Dim count As Integer c_ncx|dUs  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double d)V8FX,t  
    Dim tlens As Double, nlens As Double 4v/MZ:%C`  
    Dim curv As Double, conic As Double T8Mqu`$r  
    Dim ok As Long )EB+(c~E  
     !AJkd.  
    Sub Main ~b*]jZwT  
    Pb;c:HeI/  
        '用户输入对话框 pt"9zkPj  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 k L6s49  
            TextBox 220,21,40,21,.TextBox1 'default: 0 2DPv7\fW  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 MG=8`J-`  
            OKButton 40,91,90,21 d'Bxi"K  
            CancelButton 190,91,90,21 i,^3aZwJ'  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 sM MtU@<x  
            TextBox 220,49,40,21,.TextBox2 'default: 4 9vyf9QE;  
        End Dialog @Q,Q"c2  
        Dim dlg As UserDialog { rLgyrj$  
    \8$~ i  
        ok = Dialog (dlg) *GoTN  
    w>9d^kU'  
        If ok=0 Then    'cancel button was pressed XX /s@C  
            Print "Execution cancelled." TaD;_)(  
            End iii|;v ]+  
        End If 4@{?4k-cq  
    hsY?og_H  
        'Assign accommodation and pupil diameter & use defaults if field left empty L$3lsu!4n  
        If dlg.TextBox1 = "" Then nl 'MWP  
            A = 0           'Default accommodation 8cOft ;|qB  
        Else fWq*Op.]c  
            A = CDbl(dlg.TextBox1) 9h6Oq(0b8  
        End If -_Z4)"k  
    {aUTTEu  
        If dlg.TextBox2 = "" Then \mh #MMp  
            pupilDiam = 4   'Default pupil diameter CnL=s6XD'  
        Else `WXlq#:K  
            pupilDiam = CDbl(dlg.TextBox2) .\_RavW23  
        End If tXtNK2-1  
    z mip  
        Print " " '42$O  
        Print "Accommodation = " & A & " Diopters" DNq(\@x[!  
        Print "Pupil Diameter = " & pupilDiam & " mm" t?G6|3  
    9}9VZ r?  
        ' Calculate new parameters with accommodation 1}a4AGAp  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness jG7PT66>;  
    KWY_eY_|  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 3<W%z]k@M  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens mTI`^e  
    SC~k4&xy  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens an"~n`g  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens O_1[KiZ  
    3:nBl?G<  
        tlens = 3.767 + 0.04*A                  'Lens thickness dWQsC|  
    :CE4< {V  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction A/<u>cCW  
    z4SJxL  
        'Adjust parameters to account for accommodation '+_>PBOc  
    x ']'ODs  
        '************************************************************************* `5@F'tKQ  
        'Aqueous thickness (Position of Lens) 5_'lu  
        '************************************************************************* J;obh.}u"{  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z,#H\1v3lB  
        GetCustomElement eID, entity ;9k>; g3m  
    [o#% Eg;  
        parID = FindFullName( "Geometry.Arizona Eye" ) ia'z9  
    =|agW.l  
        ' Delete any shift(s) in z >E+g.5 ,:W  
        count = 0 JnsJ]_<  
        While GetOperationCount(eID)>count HGGq;Nbm  
            GetOperation eID, count, op .^{%hc*w4  
            If op.Type="ShiftZ" Then :Mu*E5  
                DeleteOperation eID,count S/5QK(XLC)  
                count=count-1 l@B9}Icq  
            End If NV4g5)D&L  
            count=count+1 nf /*n  
        Wend G@H!D[wd  
    4=tR_s  
        'Set new shift in iwJ_~   
        op.Type = "ShiftZ" d>hv-n D  
        op.val1 = taq geR+v+B,  
        op.parent = parID .}!.4J%q2  
        AddOperation eID, op Gc|)4c  
        Print "Set aqueous humor thickness = " & taq-0.55 *z0d~j*W;  
    gY~r{  
        '************************************************************************* uMg\s\Z  
        'Radius and conic constant of anterior lens GkJcd;  
        '************************************************************************* [Iks8ZWr_  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 1.!U{>$  
        GetConic eID, entity, curv, conic >-A@6Qe_  
    |EE1S{!24m  
        SetConic eID, entity, 1/Rant, CCant U7s$';y"%  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 4qie&:4j  
    uatUo  
        '************************************************************************* -)}s{[]d6m  
        'Radius and conic constant of posterior lens nzflUR{`-  
        '************************************************************************* )Zr9 `3[  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) '}_r/l]K  
        GetConic eID, entity, curv, conic -x//@8"   
    }sXTZX  
        SetConic eID, entity, 1/Rpost, CCpost 1]7gYNzV"  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _B^zm-}8|B  
    n"EKVw7Y  
        '************************************************************************* [%.v;+L  
        'Lens thickness (Position of posterior lens surface) \~5|~|9<  
        '************************************************************************* jfuHZ^YA  
    aas.-N T  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) .Fn|Okn^gr  
    <>3)S`C`p  
        ' Delete any z-shift(s) Ha@; Sz<R  
        count = 0 _>- D*l  
        While GetOperationCount(eID)>count ;/K2h_=3z  
            GetOperation eID, count, op cszvt2BIg  
            If op.Type="ShiftZ" Then P3_.U8g$r  
                DeleteOperation eID,count <sH}X$/  
                count=count-1 \Rny*px  
            End If L80(9Y^xn  
            count=count+1 ?"d$SK"6Z  
        Wend e,U:H~+]  
    11=$] K>  
        'Set new z-shift &~,4$& _  
        op.Type = "ShiftZ" UD.b b  
        op.val1 = tlens Jxe+LG  
        op.parent = parID W$c@C02<  
        AddOperation eID, op x}] 56f  
        Print "Set lens thickness = " & tlens W7>2&$  
    9@ tp#  
        '************************************************************************* Zl9@E;|=  
        'Lens index of refraction w_(3{P[Iz  
        '************************************************************************* HxG8 'G  
        eID = FindMaterial( "Lens" ) isZ5s\  
        GetModelMaterial eID, mat %nZl`<M  
    ":Wq<Z'  
        mat.Nd = nlens bNea5u##  
        SetModelMaterial eID, mat Y?0/f[Ax,y  
        Print "Set lens index of refraction = " & nlens JVE\{ e)  
    GShxPH{_j  
        '************************************************************************* j_Szw w-  
        'Pupil diameter %**f`L%jN  
        '************************************************************************* P-@MLIC{  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) [^5\Ww  
    = S&`~+  
        'Adjust pupil diameter (trimming volume inner hole) fj_23{,/"g  
    6Z2,:j;  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" tb3V qFx  
    /DYyl/  
        ' Adjust pupil location to just in front of the lens g68p9#G  
        parID = FindFullName( "Geometry.Arizona Eye" ) nr!N%Hi  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Ed9Uw 7  
        count = 0 "s+4!,k  
        While GetOperationCount(eID)>count U&5* >fd=  
            GetOperation eID, count, op .G0 N+)  
            If op.Type="ShiftZ" Then 5~*)3z^V  
                DeleteOperation eID,count /(N/DMl[  
                count=count-1 Wl j&_~  
            End If / ;]5X  
            count=count+1 *3GV9'-P  
        Wend uw)7N(os\`  
        op.Type = "ShiftZ" [0H0%z#tU&  
        op.val1 = taq-0.01 .Mt3e c<  
        op.parent = parID f[^f/jGm  
        AddOperation eID, op M;(,0dk  
    zKJ2 ~=  
        Print "Set pupil diameter = " & pupilDiam ,?fJ0n:!%  
    H];B?G';C  
        'Update AZ Eye subassembly Description m~=~DMj  
        eID = FindFullName( "Geometry.Arizona Eye" ) G95,J/w  
        GetEntity eID, entity +# W94s~0V  
        entity.Description = "Accommodation = " & A & "D" 6  63o  
        SetEntity eID, entity W'lqNOX[v  
    zzqJeIS  
        Update }Mc b\+[  
        Print "DONE!" }r:o8+4  
         sibYJKOy  
    End Sub \/A.j|by,>  
    S{@}ECla  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: JAPr[O&  
    yIMqQSt79z  
    Accommodation = 4 Diopters ZCiCZ)oc  
    Pupil Diameter = 4 mm ]MbPivM  
    Set aqueous humor thickness = 2.81 mgs(n5V5  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 V~J5x >O  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 &d#R'Z  
    Set lens thickness = 3.927 :+rGBkw1m  
    Set lens index of refraction = 1.42672 #(8|9  
    Set pupil diameter = 4 bDI%}k9#  
    DONE! 7N.b-}$(  
    d=!:UB  
    (文章来源:讯技光电)
     
    分享到