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    [转载]FRED运用:Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2016-02-24
    简介 {z7kW@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。 E9:p A5H-j  
    Z~HLa  
    模型 T*zy^we  
    J|N>}di  
    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。 ~0Xx]  
    2hE+Om^n  
    Table 1. AZ眼睛模型的定义
    WZ^u%Z  
    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. `d!~)D  
    k~pbXA*u  
    光源 <77v8=as5  
    'kk B>g7B  
    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。 lBfG#\rdW~  
    tk'3Q1L  
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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。 -mqTlXM  
    Nj;G%KAP  
    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。 JURJN+)z  
    99&PY[f:{  
    图2. 字母F光源的设定方法光 # {|F2AM  
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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 aXyg`CDv  
    :qO)^~x  
    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。 I=o/1:[-  
     iT&Y9  
    =-8y =  
    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。 !-Md+I_  
    >d#Ks0\&  
    $Qq5Fx9kU  
    图5. 视网膜重点采样规格设定
    G~`nLC^Y  
    脚本 @-5V~itW  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: 6yPh0n  
    i`HXBq!|w  
    图6. 用户对话框的创建与编辑
    S`Wau/7t  
    图7. 用户对话框编辑器
    ~h6aTN  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 - ]Mp<Y  
    余下的脚本计算与屈光度有关的所有参数。 "xY]&  
    D-4\AzIb  
    分析 .T }q"  
    <%Afa#  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ~4[4"Pi>|  
    DJ<F8-sb2r  
    图7. 字母F在视网膜上颜色分析
    EJZb3  
    脚本代码 L(i0d[F  
    &P3ep[]j  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. !L\P.FP7b  
    ik Pm,ZN  
    Dim entity As T_ENTITY QX&1BKqWn  
    Dim op As T_OPERATION =K\.YKT  
    Dim mat As T_MODELMATERIAL 0I \l_St@  
    Dim A As Double /J` ZO$  
    Dim pupilDiam As Double k4Ub+F  
    Dim eID As Long kmfxk/F}  
    Dim parID As Long > ;zQ.2*  
    Dim count As Integer #ZvDf5A  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double / |z_z%=  
    Dim tlens As Double, nlens As Double + c"$-Jr  
    Dim curv As Double, conic As Double W! q-WU  
    Dim ok As Long cp g+-Zf%  
    >zY~")|R(  
    Sub Main CPS1b  
    &[iunJv:eq  
        '用户输入对话框 NamO5(1C  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 UO{3v ry48  
            TextBox 220,21,40,21,.TextBox1 'default: 0 WjsE#9D!of  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ;H:+w\?8f$  
            OKButton 40,91,90,21 ~G*eJc0S:  
            CancelButton 190,91,90,21 q'~F6$kv5  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 { WW!P,w  
            TextBox 220,49,40,21,.TextBox2 'default: 4 p^ojhrr  
        End Dialog }|!9aojr  
        Dim dlg As UserDialog &H<n76G  
    S&`iEwG  
        ok = Dialog (dlg) |g}~7*+i  
    js<}>wD7<  
        If ok=0 Then    'cancel button was pressed TB  
            Print "Execution cancelled." SF2<   
            End V]I+>Zn| 7  
        End If {s/u [T_D2  
    `lA[-x~  
        'Assign accommodation and pupil diameter & use defaults if field left empty ); <Le6  
        If dlg.TextBox1 = "" Then w` ;>+_ E7  
            A = 0           'Default accommodation ~\~K ,v  
        Else `tb@x ^  
            A = CDbl(dlg.TextBox1) ~56F<=#,  
        End If 6V@?/B  
    ]&l%L4Z  
        If dlg.TextBox2 = "" Then :i>/aRNh1  
            pupilDiam = 4   'Default pupil diameter Kc[Y .CH  
        Else q&`>&k  
            pupilDiam = CDbl(dlg.TextBox2) +f- E8q  
        End If 7w]NG`7  
    !O-9W=NJ  
        Print " " WOaj_o  
        Print "Accommodation = " & A & " Diopters" oykqCN  
        Print "Pupil Diameter = " & pupilDiam & " mm" wmf#3"n  
    o/Cu^[an  
        ' Calculate new parameters with accommodation v%%;Cp73  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness f<T"# G$5  
    sF=8E8qa   
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens KKLW-V\6K  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens a6vls]?  
    NtnKS@Ht  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens LG qg0 (  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens -P5M(Rt  
    7Odw{pc  
        tlens = 3.767 + 0.04*A                  'Lens thickness R:LT hFx  
    R6KS&Ge_  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {_{&t>s2  
    (i*;V0  
        'Adjust parameters to account for accommodation 9 yE   
    u(`,7 o "  
        '************************************************************************* WO=,NQOw  
        'Aqueous thickness (Position of Lens) vKvT7Zxc  
        '************************************************************************* (Z72 3)  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" )  @aC2]  
        GetCustomElement eID, entity H!+T2<F9R  
    edW:(19}  
        parID = FindFullName( "Geometry.Arizona Eye" ) a.5^zq7#!  
    h5.>};"@ '  
        ' Delete any shift(s) in z  h'_@  
        count = 0 Nhm)bdv]  
        While GetOperationCount(eID)>count z&@Vg`w"  
            GetOperation eID, count, op Ehv*E  
            If op.Type="ShiftZ" Then #ir~v>J||  
                DeleteOperation eID,count {hLS,Me  
                count=count-1 W r%E}mX-  
            End If N){/#3  
            count=count+1 sP+ZE>7  
        Wend 3;h%mk KQ+  
    [7:(e/&  
        'Set new shift in ~e)`D nJ  
        op.Type = "ShiftZ" ?+WSYg0  
        op.val1 = taq !VfP#B6.  
        op.parent = parID y_=},a  
        AddOperation eID, op _Zq2 <:  
        Print "Set aqueous humor thickness = " & taq-0.55 nDh D"rc  
    '{t&!M`  
        '************************************************************************* {'QA0K  
        'Radius and conic constant of anterior lens U6pG  
        '************************************************************************* QE.a2 }  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) abVz/R/o  
        GetConic eID, entity, curv, conic -zq_W+)ks  
    jd&kak  
        SetConic eID, entity, 1/Rant, CCant c-2##Pf_8O  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant .-6B6IEI_"  
    .\?)O+J!  
        '************************************************************************* <~[ A  
        'Radius and conic constant of posterior lens iYyJq;S   
        '************************************************************************* &mM[q 'V  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) U#jbii6e  
        GetConic eID, entity, curv, conic 3r)<:4a u&  
    $ +`   
        SetConic eID, entity, 1/Rpost, CCpost fgg;WXcT ~  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost tyH*epa nw  
    5Z`9L| 3d  
        '************************************************************************* *W#_W]Tu  
        'Lens thickness (Position of posterior lens surface) #^>5,M2  
        '************************************************************************* zdwr5k  
    } h.]sF  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5jpb`Axj#  
    DKjkO5R\  
        ' Delete any z-shift(s) l~/g^lN  
        count = 0 -qPYm?$  
        While GetOperationCount(eID)>count {!B^nCSL  
            GetOperation eID, count, op ?W%9H\;  
            If op.Type="ShiftZ" Then vq df-i  
                DeleteOperation eID,count (>OCLmV$  
                count=count-1 483BrFV  
            End If SLa\F  
            count=count+1 )_bR"!Z  
        Wend >l\?K8jL9  
    xJvM l`2;  
        'Set new z-shift !;YmLJk;hN  
        op.Type = "ShiftZ" eQ}o;vJN  
        op.val1 = tlens A&$oiLc  
        op.parent = parID f2sv$#'  
        AddOperation eID, op `XwFH#_  
        Print "Set lens thickness = " & tlens H$ !78/f  
    l%aiG+z%6}  
        '************************************************************************* `dH[&=S  
        'Lens index of refraction a!1\,.  
        '************************************************************************* 24TQl<H{  
        eID = FindMaterial( "Lens" ) (W<n<sl:-  
        GetModelMaterial eID, mat IT3xX=|b  
    PD$g W`V  
        mat.Nd = nlens !,mv 7Yj  
        SetModelMaterial eID, mat `YDe<@6'  
        Print "Set lens index of refraction = " & nlens n$*'J9W~  
    7R 40t3  
        '************************************************************************* pZu2[  
        'Pupil diameter Ip/_uDi+!Z  
        '************************************************************************* cG|ihG5)  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 9Bl c  
    .c[v /SB]  
        'Adjust pupil diameter (trimming volume inner hole) ZiBTe,;  
    aj1o   
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" j5*W[M9W  
    !5rja-h  
        ' Adjust pupil location to just in front of the lens :V>M{vd  
        parID = FindFullName( "Geometry.Arizona Eye" ) w6k\po=  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) c=U1/=R5  
        count = 0 sLE@Cm]k  
        While GetOperationCount(eID)>count f^8,Z+n  
            GetOperation eID, count, op O.n pi: a  
            If op.Type="ShiftZ" Then o}XbFL n  
                DeleteOperation eID,count -kp! .c  
                count=count-1 RCED K\*m  
            End If S7cxEOfAu  
            count=count+1 Ou~|Q&f'  
        Wend 7-nz'-'  
        op.Type = "ShiftZ" l65-8  
        op.val1 = taq-0.01 U*G9fpVy  
        op.parent = parID i^[yGXtW  
        AddOperation eID, op FcnSO0G%  
    fqaysy  
        Print "Set pupil diameter = " & pupilDiam y*,3P0*z  
    %m:T?![XO  
        'Update AZ Eye subassembly Description "(uEcS2<  
        eID = FindFullName( "Geometry.Arizona Eye" ) b?#k  
        GetEntity eID, entity 'H0b1t1S%  
        entity.Description = "Accommodation = " & A & "D" {/]Ks8`Dm  
        SetEntity eID, entity v3w5+F  
    Y[=Gv6Fr  
        Update p&w XRI  
        Print "DONE!" \29a@6  
         $9v:(:!Bm  
    End Sub m^dKww  
    M6E.!Cs  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: (>*<<a22  
    |A_yr/f  
    Accommodation = 4 Diopters `nA_WS  
    Pupil Diameter = 4 mm 38IVSK_  
    Set aqueous humor thickness = 2.81 M{S7tMX  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 v~>^c1:  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 [4:_6vd7X  
    Set lens thickness = 3.927 \BC|`)0h  
    Set lens index of refraction = 1.42672 k'uN2m  
    Set pupil diameter = 4 )Yvf9dl  
    DONE! _@3?yv~ D  
    @`<vd@  
    (文章来源:讯技光电)
     
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