[技术]Arizona眼睛模型 [复制链接]

简介 ,<Ag&*YE4  
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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。 g+(Cs  
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模型 ?=u/&3Cw  
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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。 h?Y->!'  
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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. qu8!fFQjYL  
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光源 ot%^FvQ[c  
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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。 a:q>7V|%$  
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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。 0f_+h %%=  
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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。 tfKf*Um  
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视网膜的散射 {th=MldJ?  
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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。 %#_"Ie  
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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。 Vx  Vpl@  
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脚本 $yn7XonS  
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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： =%)Y, )"  
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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。 [ pe{,lp  
余下的脚本计算与屈光度有关的所有参数。 2iWSk6%R  
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分析 Yy 8?X9r.  
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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。 f,}(=
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脚本代码 WR.>?IG2E  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. '=WPi_Z5:C  
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Dim entity As T_ENTITY @zCp/fo3  
Dim op As T_OPERATION $eq*@5B  
Dim mat As T_MODELMATERIAL R<<U(.E  
Dim A As Double mx!EuF$I  
Dim pupilDiam As Double n1Wo<$#  
Dim eID As Long Bjp4:;Bb  
Dim parID As Long ~Fe$/*v  
Dim count As Integer h(/& ;\Cr  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5$?)f&M  
Dim tlens As Double, nlens As Double KSYHG  
Dim curv As Double, conic As Double |muZv!,E  
Dim ok As Long *-';ycOvr  
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Sub Main 1\X_B`xwD  
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    '用户输入对话框 R*`=Bk0+  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 /8? u2 q  
        TextBox 220,21,40,21,.TextBox1 'default: 0 6QYHPz  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 96d&vm~m1  
        OKButton 40,91,90,21 Djr/!j
  
        CancelButton 190,91,90,21 $vLGX>H  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 RI3GAd  
        TextBox 220,49,40,21,.TextBox2 'default: 4 <'N~|B/yZ  
    End Dialog Y'+mC  
    Dim dlg As UserDialog =&"a:l  
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    ok = Dialog (dlg) ]^0mh["  
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    If ok=0 Then    'cancel button was pressed 6n:oEXM>  
        Print "Execution cancelled." )eVn1U2*z.  
        End 0<)Ep~!  
    End If !DkIM}.  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Vz]yJ:  
    If dlg.TextBox1 = "" Then )E*-  
        A = 0           'Default accommodation y
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    Else 9yK\<6}}QH  
        A = CDbl(dlg.TextBox1) ;3\'}2^|l  
    End If jSQM3+`b  
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    If dlg.TextBox2 = "" Then f%/6kz  
        pupilDiam = 4   'Default pupil diameter 7?ILmYBw  
    Else qV)hCc/ ~  
        pupilDiam = CDbl(dlg.TextBox2) \HL66%b[  
    End If 4*9BAv  
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    Print " " xQ! Va  
    Print "Accommodation = " & A & " Diopters" |,T"_R_K  
    Print "Pupil Diameter = " & pupilDiam & " mm"
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    ' Calculate new parameters with accommodation |F +n7  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness s{:Thgv,9  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens &-L9ws  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Q">wl  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens E <N%  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Xb@dQRVX  
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    tlens = 3.767 + 0.04*A                  'Lens thickness H<"EE1
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ;;N#'.xD  
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    'Adjust parameters to account for accommodation |\RN%w7E
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    '************************************************************************* P! P` MX  
    'Aqueous thickness (Position of Lens) R@KWiV  
    '************************************************************************* SC--jhDZ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) +hcJ!$J7  
    GetCustomElement eID, entity Of#"nu  
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    parID = FindFullName( "Geometry.Arizona Eye" ) tILnD1q  
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    ' Delete any shift(s) in z !1mAq+q!  
    count = 0 iV:\,<8d  
    While GetOperationCount(eID)>count y\:,.cZ+TQ  
        GetOperation eID, count, op .uB[zJc  
        If op.Type="ShiftZ" Then ]dT]25V  
            DeleteOperation eID,count RN$q,f[#  
            count=count-1 Q6n8,2*  
        End If !iAZEOkRR  
        count=count+1 Pr,C)uch  
    Wend X*a7`aL  
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    'Set new shift in /U>8vV+C  
    op.Type = "ShiftZ"
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    op.val1 = taq 'i;ofJ[.c  
    op.parent = parID ie/QSte  
    AddOperation eID, op W+.?J 60  
    Print "Set aqueous humor thickness = " & taq-0.55 GYonb)F  
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    '************************************************************************* f5R%F~
 
    'Radius and conic constant of anterior lens [-\DC*6  
    '************************************************************************* )+.AgqxI  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) :(I=z6  
    GetConic eID, entity, curv, conic G }M!  

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    SetConic eID, entity, 1/Rant, CCant 5;[0Q  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 3]>YBbXvE  
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    '************************************************************************* #Z]<E6<=9  
    'Radius and conic constant of posterior lens !9^GkFR6n  
    '************************************************************************* YGi_7fTyc=  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 7A  
    GetConic eID, entity, curv, conic VKi3z%kwK  
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    SetConic eID, entity, 1/Rpost, CCpost Ds\f?\Em  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /sl
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    '************************************************************************* iz-O~T/^  
    'Lens thickness (Position of posterior lens surface) mW)"~sA  
    '************************************************************************* ~5Rh7   
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) &0mhO+g
 
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    ' Delete any z-shift(s) XB%`5wwd  
    count = 0 JM*rPzp  
    While GetOperationCount(eID)>count 'eoI~*}3WQ  
        GetOperation eID, count, op h#8{fr)6  
        If op.Type="ShiftZ" Then tI2p-d9B  
            DeleteOperation eID,count CzT_$v_  
            count=count-1 <pUc( tPoz  
        End If m>b i$Y  
        count=count+1  ^9kdd[  
    Wend <zu)=W'R]  
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    'Set new z-shift ||?wRMV  
    op.Type = "ShiftZ" <7X+-%yb;  
    op.val1 = tlens wSs78c=  
    op.parent = parID yNQ 9~P2  
    AddOperation eID, op sQT,@'"  
    Print "Set lens thickness = " & tlens 3*b!]^d:D  
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    '************************************************************************* !Jo.Un7  
    'Lens index of refraction UmQ'=@^kR  
    '************************************************************************* wT\dzp>/  
    eID = FindMaterial( "Lens" ) .LNqU#a  
    GetModelMaterial eID, mat q}5&B=2pM  
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    mat.Nd = nlens lc0ZfC  
    SetModelMaterial eID, mat GG_A'eX:I  
    Print "Set lens index of refraction = " & nlens SHPZXJ{  
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    '************************************************************************* dkbKnY&  
    'Pupil diameter ;d
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    '************************************************************************* sfNAGez  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) jfrUOl'l  
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    'Adjust pupil diameter (trimming volume inner hole) O~&l.>??  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" xE.=\UzJ  
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    ' Adjust pupil location to just in front of the lens DSHpM/7  
    parID = FindFullName( "Geometry.Arizona Eye" ) ("BFI  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Yui:=GgUrr  
    count = 0 ( ]o6Pi  
    While GetOperationCount(eID)>count +NEP*mk  
        GetOperation eID, count, op 7f td2lv  
        If op.Type="ShiftZ" Then VbX$i!>8  
            DeleteOperation eID,count mwTn}h3N  
            count=count-1 9P)
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        End If )u&_}6z  
        count=count+1 Bf88f<Z  
    Wend PX'I:B]x*  
    op.Type = "ShiftZ" +e"}"]n  
    op.val1 = taq-0.01 Dl/_jM  
    op.parent = parID p:ST$1 K  
    AddOperation eID, op 4%j&]PASa1  
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    Print "Set pupil diameter = " & pupilDiam 49Ue2=PP#  
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    'Update AZ Eye subassembly Description jIc;jjAF  
    eID = FindFullName( "Geometry.Arizona Eye" ) IJXH_H_%*  
    GetEntity eID, entity c\4n7m,y  
    entity.Description = "Accommodation = " & A & "D" Bv@m)$9\+3  
    SetEntity eID, entity AQ 7e  
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    Update |:r
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    Print "DONE!" KwQO,($,]  
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End Sub <Cmsn
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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： PewPl0  
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Accommodation = 4 Diopters [Iihk5TT  
Pupil Diameter = 4 mm iK%Rq  
Set aqueous humor thickness = 2.81 o>`/,-!  
Set anterior lens radius = 10.4 and conic constant = -2.375869 X)f"`$  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 nLfnikw&  
Set lens thickness = 3.927 YJ16vb9  
Set lens index of refraction = 1.42672 M9OFK\)  
Set pupil diameter = 4 -6tF   
DONE! C${TC+z