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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 )9B:Y;>)  
    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。 +Juh:1H  
    <6/= y1QC)  
    模型 H'Nq#K  
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    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。 o,1Dqg4P3  
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    Table 1. AZ眼睛模型的定义
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    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. n}JPYu  
    NO2(vE  
    光源 zW5C1:.3K  
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    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。 vQgq]mA?  
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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。 $Asr`Q1i   
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 :b@igZ<  
    CW p#^1F  
    图2. 字母F光源的设定方法光 L5f$TLw h;  
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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 6e.[,-eU  
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    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。 yQ%"U^.m  
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    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。 Da_()e[9p  
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    图5. 视网膜重点采样规格设定
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    脚本 "VTF}#Uo  
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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: E oe}l   
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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
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    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。 n_23EcSy  
    余下的脚本计算与屈光度有关的所有参数。 >;9NtoE  
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    分析 0BK5qz  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 i=#F)AD^5#  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 Fe!9y2Mg  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used.  uMd. j$$  
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    Dim entity As T_ENTITY O|'1B>X  
    Dim op As T_OPERATION >cgpajx*  
    Dim mat As T_MODELMATERIAL 6R4<J% $P  
    Dim A As Double !Zjq9{t\"  
    Dim pupilDiam As Double k\aK?(.RC7  
    Dim eID As Long +@:L|uFU  
    Dim parID As Long uM S*(L_  
    Dim count As Integer #ekM"p  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6N" l{!  
    Dim tlens As Double, nlens As Double eR;!(Oy=A  
    Dim curv As Double, conic As Double '*T]fND4  
    Dim ok As Long @dEiVF`4:  
    4 b,N8  
    Sub Main 4XJiIa?  
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        '用户输入对话框 T?wzwGp-[  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ar ^i|`D  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Vw~\H Gs/~  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 {y-^~Q"z  
            OKButton 40,91,90,21 g0&\l}&%U  
            CancelButton 190,91,90,21 ]Kh2;>= Xj  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ,hRN\Kt)p  
            TextBox 220,49,40,21,.TextBox2 'default: 4 [TTSA2  
        End Dialog <<zI\+V  
        Dim dlg As UserDialog ;rHO&(h-  
    (K<9h L+X  
        ok = Dialog (dlg) 'i|rj W(  
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        If ok=0 Then    'cancel button was pressed ]A+o>#n}x  
            Print "Execution cancelled." EL D!{bMT  
            End |i7a@'0)  
        End If eJ@~o{,?>  
    U[\Vj_?(I  
        'Assign accommodation and pupil diameter & use defaults if field left empty h~} .G{"  
        If dlg.TextBox1 = "" Then #&8rcu;/  
            A = 0           'Default accommodation {/8Q)2*>0  
        Else z`3( ,V  
            A = CDbl(dlg.TextBox1) I;MD>%[W,  
        End If egR-w[{  
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        If dlg.TextBox2 = "" Then )"<8K}%!  
            pupilDiam = 4   'Default pupil diameter B80aw>M  
        Else 0C$vS`s&  
            pupilDiam = CDbl(dlg.TextBox2) ~)]} 91p  
        End If ~r*P]*51x  
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        Print " " -:Rp'SJ  
        Print "Accommodation = " & A & " Diopters" #JW+~FU`  
        Print "Pupil Diameter = " & pupilDiam & " mm" +j/~Af p5f  
    S4o$t -9l  
        ' Calculate new parameters with accommodation 1KE:[YQ1  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness qUJ aeQ  
    [iS$JG-  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens gAbD7SE  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |oFAGP1  
    z j{s}*  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens $jzFc!rs  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens R9o-`Wz  
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        tlens = 3.767 + 0.04*A                  'Lens thickness `` K#}3  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction YwDt.6(+,  
     #ToK$8  
        'Adjust parameters to account for accommodation k;^ :  
    Y3U9:VB  
        '************************************************************************* n# 7Pr/*0  
        'Aqueous thickness (Position of Lens) &, a3@i  
        '************************************************************************* N"7]R[*  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >{zk qvsQ&  
        GetCustomElement eID, entity bn9;7`>.  
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        parID = FindFullName( "Geometry.Arizona Eye" ) /bRg?Q  
    5"KlRuv%  
        ' Delete any shift(s) in z PL=^}{r  
        count = 0 6<'K~1do:  
        While GetOperationCount(eID)>count ] ZoPQUS?  
            GetOperation eID, count, op =r. >N\  
            If op.Type="ShiftZ" Then OjE` 1h\  
                DeleteOperation eID,count _=XX~^I,  
                count=count-1 QO;4}rq  
            End If `)$_YZq|SR  
            count=count+1 G;iEo4\?  
        Wend _.)eL3OF  
    Jf;?XP]z  
        'Set new shift in ))h6~1`  
        op.Type = "ShiftZ"  ZI>km?w  
        op.val1 = taq N@T.T=r  
        op.parent = parID k ]a*&me  
        AddOperation eID, op kAYb!h[`  
        Print "Set aqueous humor thickness = " & taq-0.55 )X+mV  
    DvXHK  
        '************************************************************************* SI:ifR&T  
        'Radius and conic constant of anterior lens e&<yX  
        '************************************************************************* .p` pG3  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) vw>jJ  
        GetConic eID, entity, curv, conic W&Y"K)`  
    uzr\oj+>  
        SetConic eID, entity, 1/Rant, CCant V&{MQWy  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant E>jh"|f:{  
    ,L> ar)B  
        '************************************************************************* PXKJ^fa  
        'Radius and conic constant of posterior lens YPDf Y<?v  
        '************************************************************************* Av J4\  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) r),PtI0X  
        GetConic eID, entity, curv, conic }ut]\]b  
    l:B;zi`)oB  
        SetConic eID, entity, 1/Rpost, CCpost iPG0o %  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost YNdrWBf)  
    :a[Ihqfg  
        '************************************************************************* $rB3m~c|  
        'Lens thickness (Position of posterior lens surface) 9=l.T/?sf  
        '************************************************************************* A;XOT6jv?  
    5N$E()m$  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1%[_`J;>Z  
    |s+0~$O;  
        ' Delete any z-shift(s) I,@r5tK o  
        count = 0 4<,|*hAT  
        While GetOperationCount(eID)>count E$s/]wnr[  
            GetOperation eID, count, op KxGX\   
            If op.Type="ShiftZ" Then vT^Sk;E  
                DeleteOperation eID,count Z3KO90O!8  
                count=count-1 ,U,By~s  
            End If (46 {r}_O  
            count=count+1 b,H[I!. %  
        Wend K+\nC)oG  
    x+5k <Xi}  
        'Set new z-shift +\ _{x/u1  
        op.Type = "ShiftZ" !v|ISyK  
        op.val1 = tlens 5v.DX`"  
        op.parent = parID b p<^R  
        AddOperation eID, op |`k .y]9  
        Print "Set lens thickness = " & tlens 66&EBX}  
    ]:]H:U]p  
        '************************************************************************* gApoX0nrv  
        'Lens index of refraction +ZsX*/TOn  
        '************************************************************************* Y qdWctUY  
        eID = FindMaterial( "Lens" ) F4#g?R ::U  
        GetModelMaterial eID, mat 6SM:x]`##,  
    B/f0P(7  
        mat.Nd = nlens R@ Y=o].2  
        SetModelMaterial eID, mat _cH@I?B  
        Print "Set lens index of refraction = " & nlens [onqNp  
    P@}Pk  
        '************************************************************************* D0G-5}s`  
        'Pupil diameter AnsjmR:Jv  
        '************************************************************************* Fqq6^um  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) \0;(VLN'U  
    R,2=&+ e  
        'Adjust pupil diameter (trimming volume inner hole) &[R8Q|1 j  
    2RtHg_d_l  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" hn)a@  
    rZ1Hf11C  
        ' Adjust pupil location to just in front of the lens K/_9f'^  
        parID = FindFullName( "Geometry.Arizona Eye" ) 'm=*u SJK  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ~,6b_W p/  
        count = 0 u0)7i.!M  
        While GetOperationCount(eID)>count fIC9WbiH-  
            GetOperation eID, count, op -4#2/GXNO  
            If op.Type="ShiftZ" Then EOKzzX7 S  
                DeleteOperation eID,count 5`[n8mU  
                count=count-1 5~ 'Ie<Y_  
            End If /?-7Fg+,  
            count=count+1 we7c`1E  
        Wend 0[A9b,MMVO  
        op.Type = "ShiftZ" 9W`Frx'h1  
        op.val1 = taq-0.01 O09ke-lC  
        op.parent = parID Yd cK&{  
        AddOperation eID, op a T  l c  
    Oc?+M 5  
        Print "Set pupil diameter = " & pupilDiam L #[]I,  
    .ae O}^  
        'Update AZ Eye subassembly Description ( n{wg(R  
        eID = FindFullName( "Geometry.Arizona Eye" ) [`=LTBt  
        GetEntity eID, entity `\| ssC8u  
        entity.Description = "Accommodation = " & A & "D" )u ?' ;  
        SetEntity eID, entity &:B<Q$g#  
    1n*W2:,z  
        Update {NM+Oj,~'  
        Print "DONE!" f3*?MXxb16  
         ?/*~;fM  
    End Sub =4!nFi  
    d^ ZMS~\*  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: E .6HpIx  
    + A_J1iJ<  
    Accommodation = 4 Diopters ,hxkk`  
    Pupil Diameter = 4 mm HG >j5  
    Set aqueous humor thickness = 2.81 u~zs* qp  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 !|?e7u7  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 L];y}]:F*  
    Set lens thickness = 3.927 W{cY6@  
    Set lens index of refraction = 1.42672 *v%rMU7,  
    Set pupil diameter = 4 M.}7pJ7f  
    DONE! 0"k |H&  
    ?ne_m:J[  
    (文章来源:讯技光电)
     
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