[技术]Arizona眼睛模型 [复制链接]

简介 pwSkwJ]  
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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。 rK;<-RE<[:  
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模型 I:al
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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。  -y_q
 
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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. .W;cz8te  
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光源 &>Y.$eW_  
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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。  cFjD*r-  
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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。 KdTWi;mV2-  
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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。 =kOo(  
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视网膜的散射 0;w 4WJJ  
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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。 Lcy6G%A  
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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。 vy-(:aH7U  
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脚本 %l%2 hvGZ  
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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： ]}&HvrOld  
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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。 9*!*n ~  
余下的脚本计算与屈光度有关的所有参数。 *xx)j:Sc2  
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分析 $RC)e7  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 7^#O{QYol  
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脚本代码 tC=K;zsXpz  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. anKflt3  
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Dim entity As T_ENTITY Smh=Q4,W  
Dim op As T_OPERATION O2lM;="  
Dim mat As T_MODELMATERIAL G;pc,\MF  
Dim A As Double G8Ow;:Ro  
Dim pupilDiam As Double m.5@qmQ  
Dim eID As Long u@Z6)r'  
Dim parID As Long \z@:OR,  
Dim count As Integer tC/+  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double au+:-Khm  
Dim tlens As Double, nlens As Double OSh'b$Z  
Dim curv As Double, conic As Double x.I?)x!C'  
Dim ok As Long lm{4x~y$h  
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Sub Main yZme
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    '用户输入对话框 dD 6
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 AJoP3Zv|?  
        TextBox 220,21,40,21,.TextBox1 'default: 0 +mO/9
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 + :b"0pu-H  
        OKButton 40,91,90,21 m_;XhO  
        CancelButton 190,91,90,21 <c,iu{:
 
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 @cG+D  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Ty
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    End Dialog (r1"!~d@  
    Dim dlg As UserDialog ZpwFC7LW  
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    ok = Dialog (dlg) F*4G@)  
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    If ok=0 Then    'cancel button was pressed (;N#Gqb6l  
        Print "Execution cancelled." 1l.HQ IS  
        End ++|e z{  
    End If 83)m#  
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    'Assign accommodation and pupil diameter & use defaults if field left empty JFkx=![  
    If dlg.TextBox1 = "" Then Z|3[Y@c\  
        A = 0           'Default accommodation |g<l|lqz|  
    Else D3+<16[,  
        A = CDbl(dlg.TextBox1) _( QW2m?K  
    End If Kj-zEl  
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    If dlg.TextBox2 = "" Then EgOiJH  
        pupilDiam = 4   'Default pupil diameter Xw162/:h  
    Else NMN&mJsmh  
        pupilDiam = CDbl(dlg.TextBox2) :p$Q3  
    End If _|COnm  
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    Print " "  "'Q~&B;@  
    Print "Accommodation = " & A & " Diopters" 8'Q&FW3"  
    Print "Pupil Diameter = " & pupilDiam & " mm" GCxmqoQ  
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    ' Calculate new parameters with accommodation ]-OF3+l4  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <^e  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens l% {<+N  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens QghL=  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens  qt.=  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens tYhNr  
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    tlens = 3.767 + 0.04*A                  'Lens thickness H_u%e*W  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction f!B\X*|  
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    'Adjust parameters to account for accommodation @3?dI@i(  
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    '************************************************************************* suN}6CI  
    'Aqueous thickness (Position of Lens) h0-CTPQ7A  
    '************************************************************************* b C"rQJg  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) l~x 6R~q  
    GetCustomElement eID, entity Z:VT%-
 
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    parID = FindFullName( "Geometry.Arizona Eye" ) $N4i)>&T2  
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    ' Delete any shift(s) in z ql_,U8Jw  
    count = 0 $KsB'BZy  
    While GetOperationCount(eID)>count
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        GetOperation eID, count, op R`%O=S*]  
        If op.Type="ShiftZ" Then Tq
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            DeleteOperation eID,count ]ia{N  
            count=count-1 uAV-wc  
        End If Ro#O{  
        count=count+1 p<Vj<6.=?  
    Wend dF+:9iiAm  
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    'Set new shift in z+j3j2  
    op.Type = "ShiftZ" 2&2t8.<  
    op.val1 = taq + $Lc'G+:  
    op.parent = parID n7bM
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    AddOperation eID, op /,+&O#SX  
    Print "Set aqueous humor thickness = " & taq-0.55 `Oe}OSxnT  
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    '************************************************************************* Qt=OiKZ  
    'Radius and conic constant of anterior lens ^:ehG9
 
    '************************************************************************* %p^`,b}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) -8sB\E  
    GetConic eID, entity, curv, conic 5Qxm\?0J
  
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    SetConic eID, entity, 1/Rant, CCant lkb,UL;V  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8q|T`ac+N  
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    '************************************************************************* #mRT>]di`D  
    'Radius and conic constant of posterior lens 7"Q;Yi2(  
    '************************************************************************* ,veI'WHMB  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) eMUt%zvb  
    GetConic eID, entity, curv, conic E<tJ8&IGk  
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    SetConic eID, entity, 1/Rpost, CCpost DhiIKd9W  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost dK7BjZTJo  
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    '************************************************************************* B\qu
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    'Lens thickness (Position of posterior lens surface) j$r2=~1  
    '************************************************************************* :a)`iJn
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'I@l$H  
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    ' Delete any z-shift(s) {\n?IGP?wd  
    count = 0 \!4_m8?  
    While GetOperationCount(eID)>count +3r4GEa Z  
        GetOperation eID, count, op }%S#d&wh$_  
        If op.Type="ShiftZ" Then ;Lk07+3G  
            DeleteOperation eID,count evz@c)8  
            count=count-1 4u7^v1/  
        End If ]=(PtzVa  
        count=count+1 b4>1UZGW-  
    Wend 4X$|jGQ\  
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    'Set new z-shift KKNQ+'?  
    op.Type = "ShiftZ" > |(L3UA9  
    op.val1 = tlens "?s  
    op.parent = parID 7K /quJ  
    AddOperation eID, op 0W]vK$\F*  
    Print "Set lens thickness = " & tlens +
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    '************************************************************************* e9rgJJ  
    'Lens index of refraction A%.ZesjAx  
    '************************************************************************* \y+@mJWa  
    eID = FindMaterial( "Lens" ) J{PNB{v  
    GetModelMaterial eID, mat a}'dIDj  
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    mat.Nd = nlens ;AJ6I*O@+  
    SetModelMaterial eID, mat 8l >Xbz  
    Print "Set lens index of refraction = " & nlens nc.:Wm6Mj  
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    '************************************************************************* Qv1cf  
    'Pupil diameter WO[O
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    '************************************************************************* X>U _v  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 9rgvwko  
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    'Adjust pupil diameter (trimming volume inner hole) `':G92}#  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" E>bpq^;r  
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    ' Adjust pupil location to just in front of the lens 5GDg_
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    parID = FindFullName( "Geometry.Arizona Eye" ) yMJ(Sf  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) F?b"Rv  
    count = 0 Zo}vV2  
    While GetOperationCount(eID)>count Ui`#B  
        GetOperation eID, count, op .T#}3C/  
        If op.Type="ShiftZ" Then B9S@G{`  
            DeleteOperation eID,count il$eO 7
 
            count=count-1 $ <Mf#.8%  
        End If 3|4<SMm  
        count=count+1 +3]V>Mv  
    Wend N@V:nCl  
    op.Type = "ShiftZ" b8|<O:]Hp  
    op.val1 = taq-0.01 S%df'bh$  
    op.parent = parID L`"V_ "Q#0  
    AddOperation eID, op o~26<Lk  
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    Print "Set pupil diameter = " & pupilDiam 05o<fa2HE  
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    'Update AZ Eye subassembly Description "&@{f:+  
    eID = FindFullName( "Geometry.Arizona Eye" ) z+<ofZ(.  
    GetEntity eID, entity o&>aYlXd  
    entity.Description = "Accommodation = " & A & "D" xpBQ(6Y  
    SetEntity eID, entity ZNJ<@K-  
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    Update ,91n  
    Print "DONE!" ]E#W[6'VtB  
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End Sub )&qr2Cm*  
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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： $ J!PSF8PL  
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Accommodation = 4 Diopters $>rKm  
Pupil Diameter = 4 mm g1~wg$`S8S  
Set aqueous humor thickness = 2.81 -x-EU#.G  
Set anterior lens radius = 10.4 and conic constant = -2.375869 I/go$@E"  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 I?_WV_T&  
Set lens thickness = 3.927 o,{]<Sm  
Set lens index of refraction = 1.42672 5),&{k!  
Set pupil diameter = 4 '~zi~Q7M  
DONE! %uvA3N>