[技术]Arizona眼睛模型 [复制链接]

简介 pBP.x#|  
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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。 ]mXLg:3B  
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模型 e$uiJNS2  
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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。 JA_BKA  
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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. [mr9(m[F  
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光源 R &4Z*?S  
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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。 `VL}.h  
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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。 ]UG*r%9  
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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。 NwR}yb6  
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视网膜的散射 TSsKfexQ  
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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。 cl*PFQp9j  
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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。 BMIyskl=i  
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脚本 (x$9~;<S*d  
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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： `g1iCF  
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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。 6Ik,zQL  
余下的脚本计算与屈光度有关的所有参数。 DK&h eVIoZ  
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分析 sW^a`VM  
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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。 >u(>aV|A  
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脚本代码 9lo[&^<  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. VNtPKtx\  
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Dim entity As T_ENTITY M}hrO-C
 
Dim op As T_OPERATION w_iamqe,  
Dim mat As T_MODELMATERIAL Bz`yfl2  
Dim A As Double fXQiNm[P  
Dim pupilDiam As Double RP`2)/sMT  
Dim eID As Long ,s^<X85gp\  
Dim parID As Long Bfv.$u00p  
Dim count As Integer J%]D%2vnk`  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #9LzY  
Dim tlens As Double, nlens As Double d'9:$!oz  
Dim curv As Double, conic As Double FCc=e{  
Dim ok As Long 3v!~cC~cI  
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Sub Main -NBiW6b~  
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    '用户输入对话框 GW2')}g  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 U~2`P  
        TextBox 220,21,40,21,.TextBox1 'default: 0 #m8sK(#lo  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 wn11\j&  
        OKButton 40,91,90,21 br,+45:  
        CancelButton 190,91,90,21 ;#G%U!p  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :<~7y.*O{  
        TextBox 220,49,40,21,.TextBox2 'default: 4 $Y
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    End Dialog sst,dA V$  
    Dim dlg As UserDialog <Jp1A# %p  
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    ok = Dialog (dlg) |@o6NZ<9N  
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    If ok=0 Then    'cancel button was pressed Jll-X\O`-  
        Print "Execution cancelled." nD,{3B#  
        End *
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    End If .%0ne:5  
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    'Assign accommodation and pupil diameter & use defaults if field left empty qSO*$1i  
    If dlg.TextBox1 = "" Then X^@[G8
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        A = 0           'Default accommodation ]5v:5:H  
    Else 8Xm@r#Oy5  
        A = CDbl(dlg.TextBox1) cQFR]i  
    End If ZcryAm:I  
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    If dlg.TextBox2 = "" Then rvwy~hO"  
        pupilDiam = 4   'Default pupil diameter s!6=|SS7  
    Else ;~sr$6  
        pupilDiam = CDbl(dlg.TextBox2) wh~sZ  
    End If N)43
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    Print " " 5su.+4z\  
    Print "Accommodation = " & A & " Diopters" ibF#$&!  
    Print "Pupil Diameter = " & pupilDiam & " mm" iY.eJlfH  
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    ' Calculate new parameters with accommodation Ud3""C5B  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness S>ugRasZ$  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens H|+tC=]4IZ  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens BQjam+u6  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens c#q"\"  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 
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    tlens = 3.767 + 0.04*A                  'Lens thickness DcFCKji  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction mTEVFm  
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    'Adjust parameters to account for accommodation ~5t?C<wo  
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    '************************************************************************* =FBIrw{w  
    'Aqueous thickness (Position of Lens) b
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    '*************************************************************************  0:d
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?*K<*wBw#  
    GetCustomElement eID, entity YIDg'a+z  
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    parID = FindFullName( "Geometry.Arizona Eye" ) (G5xkygR9  
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    ' Delete any shift(s) in z <-|SIF  
    count = 0 g[!Cj,  
    While GetOperationCount(eID)>count g
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        GetOperation eID, count, op L<@&nx  
        If op.Type="ShiftZ" Then [~?M
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            DeleteOperation eID,count caD5Pod4  
            count=count-1 $GF&x>]]  
        End If #^\}xn"[  
        count=count+1 6`"ZsO  
    Wend #'NY}6cb$  
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    'Set new shift in +{xG<Wkltz  
    op.Type = "ShiftZ" tQ0=p| T]  
    op.val1 = taq lS3 _Ild  
    op.parent = parID B,0+HoP  
    AddOperation eID, op 3o7xN=N  
    Print "Set aqueous humor thickness = " & taq-0.55 |E|T%i^}./  
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    '************************************************************************* B*Cb6'Q  
    'Radius and conic constant of anterior lens +UaO<L  
    '************************************************************************* &enlAV'#)O  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) e3rfXhp  
    GetConic eID, entity, curv, conic nh|EZp]  
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    SetConic eID, entity, 1/Rant, CCant 2))t*9;h  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 'WzUu MCx  
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    '************************************************************************* y7; 5xF?q  
    'Radius and conic constant of posterior lens s7Qyfe&>  
    '************************************************************************* Wy,"cT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) *cy.*@d  
    GetConic eID, entity, curv, conic T`mEO\f  
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    SetConic eID, entity, 1/Rpost, CCpost w}b<D#0XC  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost eHROBxH&  
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    '************************************************************************* }1\?()rB  
    'Lens thickness (Position of posterior lens surface) a}GAB@YI  
    '************************************************************************* Qf~| S9,  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) PoY>5  
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    ' Delete any z-shift(s) m^c%]5$  
    count = 0 ty9rH=1  
    While GetOperationCount(eID)>count %)dI2 J^Xf  
        GetOperation eID, count, op %8g$T6E[<2  
        If op.Type="ShiftZ" Then ev*c4^z:
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            DeleteOperation eID,count ,iohfZz  
            count=count-1 5A;"jp^ Z  
        End If 1S^'C2/b  
        count=count+1 $;ch82UiX  
    Wend *\C}Ok=  
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    'Set new z-shift uq]iMz>  
    op.Type = "ShiftZ" 3lyQn"  
    op.val1 = tlens w4`!Te  
    op.parent = parID -D$3!ccX  
    AddOperation eID, op dY 6B%V  
    Print "Set lens thickness = " & tlens frk7^5  
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    '************************************************************************* oNrEIgaA(+  
    'Lens index of refraction DwTi_8m;  
    '************************************************************************* -aA<.+  
    eID = FindMaterial( "Lens" ) '>"`)-  
    GetModelMaterial eID, mat M44_us  
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    mat.Nd = nlens kzW\z4f  
    SetModelMaterial eID, mat R+k=Ea&x  
    Print "Set lens index of refraction = " & nlens ~igRg~k:/  
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    '************************************************************************* uFMs^^#  
    'Pupil diameter f*UBigk  
    '************************************************************************* W&WB@)ie  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Xl
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    'Adjust pupil diameter (trimming volume inner hole) %+/f'6
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" iM4mkCdOO  
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    ' Adjust pupil location to just in front of the lens aS3P(s L  
    parID = FindFullName( "Geometry.Arizona Eye" ) (Be$$W  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) aA7S'[NjB  
    count = 0 K lPm=  
    While GetOperationCount(eID)>count ::kpl2r\c  
        GetOperation eID, count, op 27}.s0{D  
        If op.Type="ShiftZ" Then wEZqkV  
            DeleteOperation eID,count ~:R4))qpg  
            count=count-1 :Fw *r|  
        End If 6(!,H<bON  
        count=count+1 B/kcb
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    Wend :zRB)hd  
    op.Type = "ShiftZ" k?!
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    op.val1 = taq-0.01 ")fOup@ ^a  
    op.parent = parID ,^UcRZ8.H  
    AddOperation eID, op 3 (Gygq#  
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    Print "Set pupil diameter = " & pupilDiam 1uK)1%vK  
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    'Update AZ Eye subassembly Description F Bd+=bx,Z  
    eID = FindFullName( "Geometry.Arizona Eye" ) yz54:q?  
    GetEntity eID, entity M80}3mgP~  
    entity.Description = "Accommodation = " & A & "D" [YL sEo=  
    SetEntity eID, entity &Z;Eu'ia  
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    Update c80"8r  
    Print "DONE!" D'U\]'.  
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End Sub RlG'|xaT  
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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： s?1-$|*  
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Accommodation = 4 Diopters Pl`Bd0  
Pupil Diameter = 4 mm n^g-
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Set aqueous humor thickness = 2.81 <v1_F;{n  
Set anterior lens radius = 10.4 and conic constant = -2.375869 s (l+{b &  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 [346w <  
Set lens thickness = 3.927 zIX}[l4EW~  
Set lens index of refraction = 1.42672 ?j},O=JFn  
Set pupil diameter = 4 Y9lbf_51  
DONE! 6|>"0[4S