[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 uF\f>E)/N%  
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。 EN2/3~syO-  
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模型 ,[ M^rv  
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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。 #jR1ti)p  
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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. AG<TY<nqL  
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光源 &$E.rgtg  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 _^u^@.Q'i<  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 5QJ
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 !mRDzr7  
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视网膜的散射 t:.ZvA3  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 :~+m9r  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 piKR*|F  
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脚本 x$\w^h\F  
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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： 2 VGGSLr  
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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。 T hLR<\  
余下的脚本计算与屈光度有关的所有参数。 1(12`3  
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分析 f.y~Sew  
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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。 b5Pakz=jNM  
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脚本代码 koAM",5D  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. xg2 
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Dim entity As T_ENTITY D1VM_O  
Dim op As T_OPERATION t
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Dim mat As T_MODELMATERIAL rCa2$#Z
 
Dim A As Double 2r|!:^'?W  
Dim pupilDiam As Double &,B91H*#  
Dim eID As Long Z6vm!#\  
Dim parID As Long `2Oh0{x0*O  
Dim count As Integer ~ U,a?LR/  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double I!1nB\l  
Dim tlens As Double, nlens As Double #UpxF?A(  
Dim curv As Double, conic As Double L/R ES  
Dim ok As Long hMiuv_EO!  
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Sub Main \7Fkeo+  
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    '用户输入对话框 `e!hT@Xxa  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ?hQ,'M2  
        TextBox 220,21,40,21,.TextBox1 'default: 0 GxIw4m9  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [d_sd  
        OKButton 40,91,90,21 GI:$(<  
        CancelButton 190,91,90,21 Qb;5:U/x  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 br9`77J8  
        TextBox 220,49,40,21,.TextBox2 'default: 4 HBFuA.",  
    End Dialog mTW@E#)n  
    Dim dlg As UserDialog sC .R.  
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    ok = Dialog (dlg) f1RfNiW.  
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    If ok=0 Then    'cancel button was pressed UUt631  
        Print "Execution cancelled." q|A-h'  
        End +i[w& P  
    End If /B?hM&@z  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ymsqJ   
    If dlg.TextBox1 = "" Then d">Ya !W  
        A = 0           'Default accommodation \O7?!i  
    Else E+&]96*Lby  
        A = CDbl(dlg.TextBox1) =/Dp*  
    End If `f2m5qTP%  
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    If dlg.TextBox2 = "" Then (qP !x 2j  
        pupilDiam = 4   'Default pupil diameter '7<@(HO  
    Else DvuL1MeKo  
        pupilDiam = CDbl(dlg.TextBox2) 2ju1<t,8)  
    End If .F~EQ %  
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    Print " " qKL_1 ~  
    Print "Accommodation = " & A & " Diopters" |7CH  
    Print "Pupil Diameter = " & pupilDiam & " mm" ^w<:UE2a!  
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    ' Calculate new parameters with accommodation Te{L@sj  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness vR?L/G^.  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens k*4?fr  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens (!';  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Lh &L5p7  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a<V=C  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Oz9k.[j(  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction J<_&f_K0]  
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    'Adjust parameters to account for accommodation O'."ca]:5  
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    '************************************************************************* uF T\a=  
    'Aqueous thickness (Position of Lens) ^;YD3EZw  
    '************************************************************************* 'q[V*4g  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) T^GdN_qF  
    GetCustomElement eID, entity >t8eVMMa  
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    parID = FindFullName( "Geometry.Arizona Eye" ) y|KDh'Y  
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    ' Delete any shift(s) in z "0L@cOyG  
    count = 0 $^7&bQ  
    While GetOperationCount(eID)>count !*%3um  
        GetOperation eID, count, op Pr<?E[  
        If op.Type="ShiftZ" Then &TbnZnv  
            DeleteOperation eID,count hJ:Hv.{`)W  
            count=count-1 (oJ#`k:&n  
        End If i6m;2 UAa  
        count=count+1 kXX RMR  
    Wend % wRJ"T`Tt  
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    'Set new shift in o7 !@WOeZ3  
    op.Type = "ShiftZ" F{T|lTl  
    op.val1 = taq :OI!YR%"  
    op.parent = parID v;K\#uc_  
    AddOperation eID, op sCb?TyN'n  
    Print "Set aqueous humor thickness = " & taq-0.55 `%ymg8^  
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    '************************************************************************* dy`~%lX?  
    'Radius and conic constant of anterior lens EoY#D'[  
    '************************************************************************* T  |j^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6ldDt?iSg  
    GetConic eID, entity, curv, conic 3!$rp- !<)  
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    SetConic eID, entity, 1/Rant, CCant 5?vIkf  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant [=E<iPl  
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    '************************************************************************* *
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    'Radius and conic constant of posterior lens mI`dZ3h  
    '************************************************************************* F37,u|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 7SqsVq`[~  
    GetConic eID, entity, curv, conic x@k9]6/zs  
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    SetConic eID, entity, 1/Rpost, CCpost f:utw T  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Ta[}k/zW  
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    '************************************************************************* lMO0d_:b1  
    'Lens thickness (Position of posterior lens surface) ,zw  
    '************************************************************************* zR<jZwo]#  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) yz+r@I5  
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    ' Delete any z-shift(s) yWK[@;S]%  
    count = 0 Y.C*|p#  
    While GetOperationCount(eID)>count /V*eAn8>  
        GetOperation eID, count, op z`_N|iEd  
        If op.Type="ShiftZ" Then FP\[7?ZLn  
            DeleteOperation eID,count D>1D
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            count=count-1 7xd}J(l  
        End If >ab=LDoM  
        count=count+1 Je*gMq:D  
    Wend {"y6l  
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    'Set new z-shift 5
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    op.Type = "ShiftZ" `150$*K&B  
    op.val1 = tlens ~gAx  
    op.parent = parID R`<E3J\*  
    AddOperation eID, op 6RtpB\hq  
    Print "Set lens thickness = " & tlens /;>EyWW  
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    '************************************************************************* d8K^`k+x  
    'Lens index of refraction }$UFc1He\J  
    '************************************************************************* 2]'ozs$|v  
    eID = FindMaterial( "Lens" ) jW*A(bK8:  
    GetModelMaterial eID, mat _8`|KY  
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    mat.Nd = nlens {p/m+m  
    SetModelMaterial eID, mat cP Y^Bf5)  
    Print "Set lens index of refraction = " & nlens j?,$*Fi  
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    '************************************************************************* <*\J 6:^n  
    'Pupil diameter xphqgOc12,  
    '************************************************************************* _96&P7  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) .6hH}BM  
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    'Adjust pupil diameter (trimming volume inner hole) )Qc$UI8L  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" xWMMHIu  
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    ' Adjust pupil location to just in front of the lens 83n: h08  
    parID = FindFullName( "Geometry.Arizona Eye" ) ?b0\[  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) p)ONw
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    count = 0 68SM br  
    While GetOperationCount(eID)>count OwEz(pj@  
        GetOperation eID, count, op MoA{ /{  
        If op.Type="ShiftZ" Then f0F$*"#G  
            DeleteOperation eID,count N4:'X6u;  
            count=count-1 (!b: gG  
        End If F~Li.qF  
        count=count+1 `#]\Wnp~y  
    Wend Vh<`MS0X  
    op.Type = "ShiftZ" s5pY)6)  
    op.val1 = taq-0.01 0v_8YsZ!`$  
    op.parent = parID W< n`[  
    AddOperation eID, op
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    Print "Set pupil diameter = " & pupilDiam /F_ :@#H  
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    'Update AZ Eye subassembly Description Yx"z&J9p  
    eID = FindFullName( "Geometry.Arizona Eye" ) Vo%d;>!G\;  
    GetEntity eID, entity VC.?]'OqD  
    entity.Description = "Accommodation = " & A & "D" X=3@M_Jzo  
    SetEntity eID, entity g|P hNo  
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    Update e-VLU;  
    Print "DONE!" "|.(yN  
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End Sub ZwMw g t  
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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：
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Accommodation = 4 Diopters "7HB3?2>W  
Pupil Diameter = 4 mm /Uc*7Y5j  
Set aqueous humor thickness = 2.81 Ps7%:|K]
  
Set anterior lens radius = 10.4 and conic constant = -2.375869 )hug<D *h  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 z m'jk D|  
Set lens thickness = 3.927 0U>Q<I}  
Set lens index of refraction = 1.42672 R%%`wmG)"  
Set pupil diameter = 4 `y`xk<q  
DONE! k3 l  
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