切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 14324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 QX(:!b  
    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。 8KoPaq   
    ]Dx?HBM"DC  
    模型 IHagRldG  
    )SDGj;j+  
    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。 )XO2DY1/&  
    $h_@`j  
    Table 1. AZ眼睛模型的定义
    wp*;F#: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. (x=NA )  
    T 86}^=-5  
    光源 5jjJQ'  
    C!Tl?>Tt  
    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。 ?on3z  
    &aHj;Z(  
    hZzsZQ`  
    图1. 光源和提示信息使用
    FP9ZOoog  
    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。 * rs_k/2(  
    'Y"q=@Ei9  
    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。 `C!Pe84(  
    o-)E_X  
    图2. 字母F光源的设定方法光 ! B)Em  
    n!tCz<v  
    图3. 字母F在视网膜上位置点列图
    $rjv4e}7  
    视网膜的散射 u8[X\f  
    }:hdAZ+z  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 {ZfTUt)-P  
    V@Po}  
    yr;oq(&N  
    图4. 视网膜朗伯散射设定
    Jn:GqO  
    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 Vx#xq#wK  
    ,%ajIs"Gi  
    %HSoQ?qA  
    图5. 视网膜重点采样规格设定
    _N<qrH^;  
    脚本 7`WK1_rR\  
    TkQ05'Qc  
    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: a>Q7Qn  
    zizrc.g/Yg  
    图6. 用户对话框的创建与编辑
    :W'1Q2  
    图7. 用户对话框编辑器
    PqP)<d '/  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 ^|gN?:fA}  
    余下的脚本计算与屈光度有关的所有参数。 4`*jF'N[  
    * |,V$  
    分析 wPG3Ap8L  
    q+m&V#FT%  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 8"S0E(,mu  
    N:&Gv'`  
    图7. 字母F在视网膜上颜色分析
    n ~ =]/  
    脚本代码 #~ >0Dr  
    &t6L8[#yd  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. w\\    
    #FeM.k6  
    Dim entity As T_ENTITY ]*v%(IGK  
    Dim op As T_OPERATION %_/_klxnO  
    Dim mat As T_MODELMATERIAL |:EUh  
    Dim A As Double X#Hs{J~@p  
    Dim pupilDiam As Double $%!]tNGS  
    Dim eID As Long 2j_L jY'7  
    Dim parID As Long z1YC%Y|R  
    Dim count As Integer ZB%7Sr0  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double p_mP'  
    Dim tlens As Double, nlens As Double cZHlW|$R  
    Dim curv As Double, conic As Double GadD*psD2  
    Dim ok As Long KWd]?e)  
    ,NVQ C=  
    Sub Main EW YpYMkm  
    Pw+cpM 8<  
        '用户输入对话框 WMYvE\"  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 3:76x  
            TextBox 220,21,40,21,.TextBox1 'default: 0 DuCq16'0T  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ==Y^~ab;K  
            OKButton 40,91,90,21 rVZk G,Q  
            CancelButton 190,91,90,21 &}*[-z  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ^IC|3sr   
            TextBox 220,49,40,21,.TextBox2 'default: 4 m@TU2  
        End Dialog !$&K~>`  
        Dim dlg As UserDialog @mw1(J  
    g.z/%Lp K  
        ok = Dialog (dlg) AC 3 ;i  
    m:K/ )v*  
        If ok=0 Then    'cancel button was pressed h( Iti&  
            Print "Execution cancelled." MF>?! !  
            End G0<m3 Up  
        End If cp]\<p('A  
    C !uwD  
        'Assign accommodation and pupil diameter & use defaults if field left empty E Xo"F*gW  
        If dlg.TextBox1 = "" Then k}JjSt1_A;  
            A = 0           'Default accommodation &Tl3\T0D  
        Else _jP]ifu`  
            A = CDbl(dlg.TextBox1) _d,_&7  
        End If (?oK+,v?L  
    OCF= )#}qd  
        If dlg.TextBox2 = "" Then hfVJg7-  
            pupilDiam = 4   'Default pupil diameter Pq !\6s@  
        Else 'Kc;~a  
            pupilDiam = CDbl(dlg.TextBox2) ^|OxlfS  
        End If (i&:=Bfn)  
    gh3_})8c  
        Print " " @7.Ews5Mke  
        Print "Accommodation = " & A & " Diopters" 0riTav8  
        Print "Pupil Diameter = " & pupilDiam & " mm" n{=vP`V_  
    2gukK8R$  
        ' Calculate new parameters with accommodation o5A@U0c_  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness | [P!9e  
    U%m,:b6V  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ;5dJ5_}  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens PWmFY'=  
    P;][i|x  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ZC@Pfba[`  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ,n^{!^JW  
    V+-%$-w>  
        tlens = 3.767 + 0.04*A                  'Lens thickness r ",..{  
    tVFl`Xr   
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }cEcoi<v!  
    sYYNT*  
        'Adjust parameters to account for accommodation <Y9e n!3\  
    "V}WV!w  
        '************************************************************************* i=nd][1n  
        'Aqueous thickness (Position of Lens) 6||zfH  
        '************************************************************************* Z`T]jm-3  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ? 0p_/mZ  
        GetCustomElement eID, entity &M&*3  
    cY0NQKUk~  
        parID = FindFullName( "Geometry.Arizona Eye" ) \0). ODA(  
    ACctyGd  
        ' Delete any shift(s) in z ~5q1zr)E  
        count = 0 WB K6Ug  
        While GetOperationCount(eID)>count <Y:{>=  
            GetOperation eID, count, op P XKEqcQR  
            If op.Type="ShiftZ" Then ~l+2Z4nV  
                DeleteOperation eID,count _ VKBzOH  
                count=count-1 Uc^eIa@  
            End If A+de;&  
            count=count+1 g]vo."}5E  
        Wend Je5}Z.3m  
    GRM6H|.  
        'Set new shift in m}hEi  
        op.Type = "ShiftZ" OD]`oJ|  
        op.val1 = taq < KG q  
        op.parent = parID +saXN6  
        AddOperation eID, op N?`V;`[  
        Print "Set aqueous humor thickness = " & taq-0.55 1-0tG+  
    !K*(# [  
        '************************************************************************* ( RO-~-  
        'Radius and conic constant of anterior lens + fS<YT  
        '************************************************************************* z?dd5.k  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) GZH{"_$  
        GetConic eID, entity, curv, conic hz:h>Hwy  
    )Fon;/p  
        SetConic eID, entity, 1/Rant, CCant sPX&XqWx  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant %|j`z?i|  
    mX 3p   
        '************************************************************************* Znr@-=xZO*  
        'Radius and conic constant of posterior lens v|\3FEu@  
        '************************************************************************* ~-R%m  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) cX7 O*5C  
        GetConic eID, entity, curv, conic ];xDXQd  
    P q0 %oz  
        SetConic eID, entity, 1/Rpost, CCpost |;:g7eb  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost d|?Xo\+  
    I+=+ ,iXhB  
        '************************************************************************* Ps!umV  
        'Lens thickness (Position of posterior lens surface) $vrkxn  
        '************************************************************************* E75/EQ5p]p  
    "!+gA&  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) L4,b ThSG  
    is }>+&_  
        ' Delete any z-shift(s) ijsoY\V50  
        count = 0 @A4$k dJ2  
        While GetOperationCount(eID)>count .7]P-]uOZ  
            GetOperation eID, count, op 3xT9/8*  
            If op.Type="ShiftZ" Then b9-IrR4h  
                DeleteOperation eID,count 28k=@k^q  
                count=count-1 T/a=z  
            End If 8~tX>q<@q  
            count=count+1 2n)?)w]!M  
        Wend KL3Z(  
    h PL]B_<  
        'Set new z-shift C];P yQS  
        op.Type = "ShiftZ" v3#,Z!  
        op.val1 = tlens oNZ_7tU  
        op.parent = parID yQuL[#p  
        AddOperation eID, op N_I KH)  
        Print "Set lens thickness = " & tlens  D|)a7_  
    3pg=9*{  
        '************************************************************************* Fvf |m7  
        'Lens index of refraction f(Y_<%  
        '************************************************************************* N0H=;CIQ  
        eID = FindMaterial( "Lens" ) 2]1u0-M5L  
        GetModelMaterial eID, mat 1rJ2}d\y  
    w9{C"K?u=  
        mat.Nd = nlens CHsg2S  
        SetModelMaterial eID, mat o:D,,MkSw  
        Print "Set lens index of refraction = " & nlens V:$+$"|  
    f. "\~  
        '************************************************************************* B2e"   
        'Pupil diameter T5 (|{-  
        '************************************************************************* CJ* D  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) HcgvlFb  
    @@)2 12  
        'Adjust pupil diameter (trimming volume inner hole) >~SS^I0  
    nq)F$@  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" TG%B:^Yz!  
    `PC9t)%.pV  
        ' Adjust pupil location to just in front of the lens #L~i|(=U5  
        parID = FindFullName( "Geometry.Arizona Eye" ) U}LW8886  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) |@vkQ  
        count = 0 b~J)LXj]w  
        While GetOperationCount(eID)>count d=/0A\O  
            GetOperation eID, count, op lG}#K^q  
            If op.Type="ShiftZ" Then N7?B"p/  
                DeleteOperation eID,count J#zr50@@  
                count=count-1 z5kAf~A  
            End If 1@DC#2hPr  
            count=count+1 uMJ \  
        Wend 6RnzT d  
        op.Type = "ShiftZ" ;f =m+QXU  
        op.val1 = taq-0.01  Y !?'[t  
        op.parent = parID L=l&,ENy  
        AddOperation eID, op Qc; kj  
    b6bs .  
        Print "Set pupil diameter = " & pupilDiam _y@].G  
    4f([EV[6dK  
        'Update AZ Eye subassembly Description %GHGd'KO&  
        eID = FindFullName( "Geometry.Arizona Eye" ) J;C:nE|V  
        GetEntity eID, entity 1^!SuAA@  
        entity.Description = "Accommodation = " & A & "D" ;V xRaj?  
        SetEntity eID, entity /|IPBU 5  
    [={mCGU  
        Update xT%`"eM}  
        Print "DONE!" x4oWZEd  
         s/E|Z1pg3  
    End Sub uu9M}]mDl  
    <kak9 6A  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ;-+q*@sa]  
    X\AH^I6S  
    Accommodation = 4 Diopters ,#K/+T  
    Pupil Diameter = 4 mm 0cd_l 2f#g  
    Set aqueous humor thickness = 2.81 Zh=a rlk  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ^[M{s(b  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 7?$?Yu  
    Set lens thickness = 3.927 \$ytmtf5  
    Set lens index of refraction = 1.42672 F5h/>  
    Set pupil diameter = 4 i[v4[C=WB!  
    DONE! 5 4gr'qvr  
    fw%`[( hK  
    (文章来源:讯技光电)
     
    分享到