[技术]Arizona眼睛模型 [复制链接]

简介 1qA;/-Zr<o  
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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。 MQ2}
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模型 @yYkti;4-  
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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。 2,b$7xaf  
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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. hZb_P\1X  
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光源 ~n_HP_Kf?  
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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。 :ws<-Qy  
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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。 $`8wJf9@w  
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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。 $??I/6  
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视网膜的散射 53h0UL  
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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。 6y<EgYzdE  
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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。 uY*L,j^)  
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脚本 EqiY\/S  
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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： a+QpM*n7Lq  
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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。 Hn:Crl y#  
余下的脚本计算与屈光度有关的所有参数。 ]M3yLYK/P  
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分析 %iB,IEw  
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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。 2g<Xtt7+o  
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脚本代码 7HWmCaa[  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. wIgS3K  
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Dim entity As T_ENTITY unxqkU/<Z  
Dim op As T_OPERATION FI.\%x  
Dim mat As T_MODELMATERIAL AZ<=o  
Dim A As Double tJmTBsn  
Dim pupilDiam As Double 6u%&<")4HP  
Dim eID As Long +C)~bb*  
Dim parID As Long fQFk+C  
Dim count As Integer V
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double VU#7%ufu&  
Dim tlens As Double, nlens As Double d-%hjy3N  
Dim curv As Double, conic As Double 2<6UwF  
Dim ok As Long TA\vZGJ('  
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Sub Main ,%y/kS]  
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    '用户输入对话框 p<%d2@lp  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 a9Vi];  
        TextBox 220,21,40,21,.TextBox1 'default: 0 \<K5ZIWV  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 "M0z(NkH  
        OKButton 40,91,90,21 ^rz_f{c]-  
        CancelButton 190,91,90,21 )%]J>&/0J  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 i~72bMwsA  
        TextBox 220,49,40,21,.TextBox2 'default: 4 jWgX_//!  
    End Dialog +|f@^-  
    Dim dlg As UserDialog 3c%caK  
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    ok = Dialog (dlg) iRBfx  
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    If ok=0 Then    'cancel button was pressed UZ";a453r  
        Print "Execution cancelled." wM{s|Ay  
        End 
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    End If I 6O  
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    'Assign accommodation and pupil diameter & use defaults if field left empty R!1p^~/  
    If dlg.TextBox1 = "" Then _dU\JD  
        A = 0           'Default accommodation 4z)]@:`}z  
    Else k{0o9,  
        A = CDbl(dlg.TextBox1) 4!$"ayGv;D  
    End If <naz+QK'  
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    If dlg.TextBox2 = "" Then |a@L}m  
        pupilDiam = 4   'Default pupil diameter ,u m|1dh  
    Else Ca-j?bb!  
        pupilDiam = CDbl(dlg.TextBox2) [Qr"
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    End If [hsds\  
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    Print " " W3RT{\  
    Print "Accommodation = " & A & " Diopters" P2Y^d#jO  
    Print "Pupil Diameter = " & pupilDiam & " mm" 6C)_  
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    ' Calculate new parameters with accommodation S>{~nOYt-`  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness X?Au/  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens IA(5?7x`<  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Ca\6v
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;kK/_%gN-G  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ho%CDz z  
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    tlens = 3.767 + 0.04*A                  'Lens thickness _B0L.eF  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction v0y(58Rz.  
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    'Adjust parameters to account for accommodation n`KY9[0U=  
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    '************************************************************************* =">NQ)98u  
    'Aqueous thickness (Position of Lens) g .\[o@H  
    '************************************************************************* ~s{$WL&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) D,6:EV"sa  
    GetCustomElement eID, entity n:X y6H  
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    parID = FindFullName( "Geometry.Arizona Eye" ) _-\#i  
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    ' Delete any shift(s) in z nP$9CA  
    count = 0 d'2A,B~_*  
    While GetOperationCount(eID)>count DI%saw  
        GetOperation eID, count, op y}H!c;  
        If op.Type="ShiftZ" Then qWw=8Bq  
            DeleteOperation eID,count YzWz|  
            count=count-1 Q.[0ct  
        End If (#
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        count=count+1 /
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    Wend K%d&EYoW]  
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    'Set new shift in :pUtSs7p}  
    op.Type = "ShiftZ" h$*!8=M  
    op.val1 = taq [gB+C84%%  
    op.parent = parID F5Va+z,jg  
    AddOperation eID, op 8-i#8'/x  
    Print "Set aqueous humor thickness = " & taq-0.55 l^qI,M  
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    '************************************************************************* @.C2LIb  
    'Radius and conic constant of anterior lens {8OCXus3m  
    '************************************************************************* ]{iQ21`a-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) f<H2-
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    GetConic eID, entity, curv, conic HP=+<]?{G  
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    SetConic eID, entity, 1/Rant, CCant #F#%`Rv1  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant RpF&\x>  
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    '************************************************************************* =fbWz  
    'Radius and conic constant of posterior lens o@Oqm>]SS  
    '************************************************************************* ]oxZ77ciL  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +0~YP*I`/  
    GetConic eID, entity, curv, conic ]! dTG  
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    SetConic eID, entity, 1/Rpost, CCpost "8RSvT<W^5  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost OH88n69  
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    '************************************************************************* 6-I'>\U~  
    'Lens thickness (Position of posterior lens surface) jF>[?L  
    '************************************************************************* : 'c&,oLY  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) `g,..Ns-r  
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    ' Delete any z-shift(s) J1vR5wbu  
    count = 0 25T18&R  
    While GetOperationCount(eID)>count Q@niNDaW2  
        GetOperation eID, count, op y^k$Us  
        If op.Type="ShiftZ" Then ~BF&rx5Q  
            DeleteOperation eID,count SIllU  
            count=count-1 <UI [%yXj  
        End If Tk>#G{Wb-  
        count=count+1 H[gWGbPq7  
    Wend %RVZD#zr  
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    'Set new z-shift a}d@ T  
    op.Type = "ShiftZ" 4JE
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    op.val1 = tlens [e q&C_|D  
    op.parent = parID 4W])}C%  
    AddOperation eID, op !W\+#ez  
    Print "Set lens thickness = " & tlens SKtrtm  
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    '************************************************************************* mR~&)QBP.  
    'Lens index of refraction s.#`&Sd>  
    '************************************************************************* 92c HwWZ!  
    eID = FindMaterial( "Lens" ) omFz@  
    GetModelMaterial eID, mat @c#(.=  
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    mat.Nd = nlens [RL9>n8f  
    SetModelMaterial eID, mat ,I9bNO,%JK  
    Print "Set lens index of refraction = " & nlens 5tnlrqC  
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    '*************************************************************************  bLL2  
    'Pupil diameter us.~G  
    '************************************************************************* QnDg6m)+  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) D=$)n_F  
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    'Adjust pupil diameter (trimming volume inner hole) Fcx&hj1gQ  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" C^){.UGmJ  
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    ' Adjust pupil location to just in front of the lens ~~.}ah/_d  
    parID = FindFullName( "Geometry.Arizona Eye" ) b$7 +;I;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) {vj)76%y  
    count = 0 YR70BOxK  
    While GetOperationCount(eID)>count [ )F<V!  
        GetOperation eID, count, op 5(2;|I,T  
        If op.Type="ShiftZ" Then "7 yD0T)2  
            DeleteOperation eID,count 7=uj2.J6  
            count=count-1 JC"z&ka  
        End If QPx^_jA  
        count=count+1 +t.b` U`-  
    Wend IBGrt^$M  
    op.Type = "ShiftZ" h1RSVp+?n  
    op.val1 = taq-0.01 54,er$$V  
    op.parent = parID / 1RpM]d  
    AddOperation eID, op jdN`mosJ  
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    Print "Set pupil diameter = " & pupilDiam F@t3!bj9  
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    'Update AZ Eye subassembly Description qK+5NF|  
    eID = FindFullName( "Geometry.Arizona Eye" )
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    GetEntity eID, entity mDWG7Asp  
    entity.Description = "Accommodation = " & A & "D" im8CmQ  
    SetEntity eID, entity VTM/hJmwJ  
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    Update '"^'MXa  
    Print "DONE!" bcyzhK=  
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End Sub VVZ'i.*_3?  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： @~e5<:|5#  
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Accommodation = 4 Diopters 6863xOv{T  
Pupil Diameter = 4 mm mw!F{pw  
Set aqueous humor thickness = 2.81 7pd$\$  
Set anterior lens radius = 10.4 and conic constant = -2.375869 3]>| i  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 /z!%d%"  
Set lens thickness = 3.927 F2WKd1U  
Set lens index of refraction = 1.42672 qM`}{ /i  
Set pupil diameter = 4 [
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DONE! sB</DS