[技术]Arizona眼睛模型 [复制链接]

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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。 2YP"nj#  
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模型 c_8mQ  
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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。 %N_S/V0`  
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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. O
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光源 BQfAen]  
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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。 X=c ,`&^  
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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。 `R=_t]ie  
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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。 &8YI)G%  
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视网膜的散射 2dJ)4  
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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。 WF.$gBH"  
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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。 ia.B@u1/  
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脚本  G/;aZ  
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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： I8wVvs;k  
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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。 :v ~q  
余下的脚本计算与屈光度有关的所有参数。 @uD{`@[  
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分析 mP+yjRw  
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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。 H LGy"P  
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脚本代码 xJ5!`#=  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. JU+'UK630  
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Dim entity As T_ENTITY l:}4 6%  
Dim op As T_OPERATION $ !=:ES  
Dim mat As T_MODELMATERIAL HBGA lZ  
Dim A As Double k}qiIMdI  
Dim pupilDiam As Double *dgN
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Dim eID As Long |^!@
  
Dim parID As Long 4=cq76  
Dim count As Integer ZJM^P'r.1c  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double xGk4KcxKs  
Dim tlens As Double, nlens As Double ^C T}i'  
Dim curv As Double, conic As Double "b7C0NE  
Dim ok As Long '" yl>"  
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Sub Main yt,;^o^  
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    '用户输入对话框 Jx?>1q=M  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ;Nij*-U4~  
        TextBox 220,21,40,21,.TextBox1 'default: 0 z|H>jit+  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ?Qk#;~\yB  
        OKButton 40,91,90,21 OO>2oH  
        CancelButton 190,91,90,21 Gjr2]t;E  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 [hbIv  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ij5YV3  
    End Dialog D3ad2vH  
    Dim dlg As UserDialog uD3_'a  
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    ok = Dialog (dlg) {Wo7=a
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    If ok=0 Then    'cancel button was pressed V;(LeuDH|  
        Print "Execution cancelled." "dTXT  
        End 2=EKAg=S  
    End If -}o;Y)  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ?f&I"\y  
    If dlg.TextBox1 = "" Then ow"Xv  
        A = 0           'Default accommodation >Z%`&D~u  
    Else 63=m11Z4  
        A = CDbl(dlg.TextBox1) K-3 _4As  
    End If g=Di2j{A  
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    If dlg.TextBox2 = "" Then 3I+pe;  
        pupilDiam = 4   'Default pupil diameter 605|*(  
    Else (6nw8vQ  
        pupilDiam = CDbl(dlg.TextBox2) >.|gmo>b  
    End If r;z A `  
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    Print " " }T,uw8?f!  
    Print "Accommodation = " & A & " Diopters" O;2 u1p'iP  
    Print "Pupil Diameter = " & pupilDiam & " mm" /eQn$ZRP,  
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    ' Calculate new parameters with accommodation 'Nh^SbD+_|  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness |k+^D:  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens h.*|4;  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens P*>V6SK>b  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 7nmo p7  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens i(WWF#N5  
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    tlens = 3.767 + 0.04*A                  'Lens thickness :R)IaJ6)  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 9L}
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    'Adjust parameters to account for accommodation (k?OYz]c  
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    '************************************************************************* Z(L>~+%  
    'Aqueous thickness (Position of Lens) [#:k3aFz  
    '************************************************************************* /
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) nMhc3t  
    GetCustomElement eID, entity DsoF4&>g[B  
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    parID = FindFullName( "Geometry.Arizona Eye" ) *4ID$BmO  
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    ' Delete any shift(s) in z ?g'l/xuRe  
    count = 0 /vu7;xVG  
    While GetOperationCount(eID)>count `)'YU^s  
        GetOperation eID, count, op b#sO1MXv  
        If op.Type="ShiftZ" Then  KLX>QR@  
            DeleteOperation eID,count z8oSh t`+  
            count=count-1 v[m>;Ubg&  
        End If {0?

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        count=count+1 FX{Sb"  
    Wend ||hd(_W8  
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    'Set new shift in L(.5:&Y=`  
    op.Type = "ShiftZ"
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    op.val1 = taq [8ih-k  
    op.parent = parID JH 8^ZP:d'  
    AddOperation eID, op o!Y7y1$  
    Print "Set aqueous humor thickness = " & taq-0.55 % 74}H8q_z  
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    '************************************************************************* N)QW$iw9  
    'Radius and conic constant of anterior lens L!\I>a5C0G  
    '************************************************************************* 'Ag?#vB  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) L~\Ir  
    GetConic eID, entity, curv, conic _T1|_9b  
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    SetConic eID, entity, 1/Rant, CCant yJ?6BLJi  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant d;K,2  
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    '************************************************************************* LqNsQu";  
    'Radius and conic constant of posterior lens WmeV[iI  
    '************************************************************************* L:7%Wd
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) zpJQ7hym  
    GetConic eID, entity, curv, conic y6fYNB  
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    SetConic eID, entity, 1/Rpost, CCpost [&51m^  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost A\LMmg  
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    '************************************************************************* V3 2F  
    'Lens thickness (Position of posterior lens surface) Lc=t,=OhGe  
    '************************************************************************* ?|kwYA$4o  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) a0~LZQ?  
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    ' Delete any z-shift(s) @kd`9Yw  
    count = 0 0.+MlyA  
    While GetOperationCount(eID)>count ]V^ >aUlj  
        GetOperation eID, count, op MaN6bM  
        If op.Type="ShiftZ" Then x.8fxogz  
            DeleteOperation eID,count DZ"'GQSg  
            count=count-1 {\hjKP   
        End If 1 8%+ Hy=  
        count=count+1 Qco8m4n  
    Wend JVydTvc  
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    'Set new z-shift 2{|Z?3FJ^  
    op.Type = "ShiftZ" !y+uQ_IS@  
    op.val1 = tlens -Gy=1W`09  
    op.parent = parID gWQ(
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    AddOperation eID, op OYSq)!:  
    Print "Set lens thickness = " & tlens :er(YWF:  
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    '************************************************************************* L>LIN 1
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    'Lens index of refraction ?zex]!R  
    '************************************************************************* xpX<iT>5u  
    eID = FindMaterial( "Lens" ) y4U|~\]  
    GetModelMaterial eID, mat  LAkBf  
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    mat.Nd = nlens :{+~i.*  
    SetModelMaterial eID, mat k3K*{"z  
    Print "Set lens index of refraction = " & nlens 0<7sM#sI!  
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    '************************************************************************* Idb*,l|<  
    'Pupil diameter {n|ah{_p|  
    '************************************************************************* rY6x):sC  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) elAWQEus  
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    'Adjust pupil diameter (trimming volume inner hole) 7HkFDI()1  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 6se8`[  
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    ' Adjust pupil location to just in front of the lens cI P.5)Ca  
    parID = FindFullName( "Geometry.Arizona Eye" ) & XmaGtt  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]XU4nNi  
    count = 0 hs[x\:
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    While GetOperationCount(eID)>count =WjHf8v;  
        GetOperation eID, count, op +}O -WX?  
        If op.Type="ShiftZ" Then 1^LdYO?g'  
            DeleteOperation eID,count u"q56}Q?]  
            count=count-1 <Xl#}6II  
        End If w+/`l*  
        count=count+1 kN.;;HFq#  
    Wend arDl2T,igF  
    op.Type = "ShiftZ" Rjq Xz6  
    op.val1 = taq-0.01 yI 2UmhA  
    op.parent = parID g35!a<JW  
    AddOperation eID, op z3y{0<3  
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    Print "Set pupil diameter = " & pupilDiam `*Yw-HL  
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    'Update AZ Eye subassembly Description B~w$j/sWU  
    eID = FindFullName( "Geometry.Arizona Eye" ) S[1<Qrv]  
    GetEntity eID, entity sqrLys_S  
    entity.Description = "Accommodation = " & A & "D" qtExd~E  
    SetEntity eID, entity M@R"-$Z  
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    Update @khFk.LBD  
    Print "DONE!" x="Wqcnj{  
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End Sub Y~AjcqS  
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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： itg_+%^R  
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Accommodation = 4 Diopters ob\-OMNs@  
Pupil Diameter = 4 mm n9'3~qVZ  
Set aqueous humor thickness = 2.81 p?i.<Z  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ( zWBrCX  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 sp,-JZD  
Set lens thickness = 3.927 J#I RbO)  
Set lens index of refraction = 1.42672 ij ?7MP  
Set pupil diameter = 4 .xN<<+|_v'  
DONE! g'7E6n"!,