[技术]Arizona眼睛模型 [复制链接]

简介 }6u2*(TmD  
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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。 OFU/gaO~  
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模型 `'S0*kMT  
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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。 K`-!uZW:B7  
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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. c3TKl/  
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光源 o4y']JSN  
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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。 1GCzy
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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。 Di.3113t  
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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。 5*g]qJF  
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视网膜的散射  AnBJ(h  
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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。 ~wm;;#_O  
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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。 /#NYi,<{X  
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脚本 "_UdBG  
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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： qy1F*kY  
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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。 J5Z%ImiT^O  
余下的脚本计算与屈光度有关的所有参数。 zw<p74DH  
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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。 G6P)C##ibn  
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脚本代码 UB`ToE|Ii  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. WS8+7O'1\  
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Dim entity As T_ENTITY g6t"mkMY L  
Dim op As T_OPERATION inb^$v  
Dim mat As T_MODELMATERIAL POI.]1i  
Dim A As Double Ox!U8g8c  
Dim pupilDiam As Double QS.>0i/7l  
Dim eID As Long g1E~+@  
Dim parID As Long +yob)%  
Dim count As Integer \`<cH#  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double <:>SGSE9  
Dim tlens As Double, nlens As Double wFh8?Z3u_  
Dim curv As Double, conic As Double n%^ LPD  
Dim ok As Long >Hb^P)3  
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Sub Main !rDdd%Z  
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    '用户输入对话框 f*{ YFg?*&  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 r~-.nb"P  
        TextBox 220,21,40,21,.TextBox1 'default: 0 v44}%$  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 V"o7jsFH6n  
        OKButton 40,91,90,21 hVT~~n`Rj  
        CancelButton 190,91,90,21 ]r!>{  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 #o/H~Iv  
        TextBox 220,49,40,21,.TextBox2 'default: 4 #ge)2  
    End Dialog 0 S_':r   
    Dim dlg As UserDialog ,21 np  
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    ok = Dialog (dlg) 0_P}z3(M  
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    If ok=0 Then    'cancel button was pressed .o1^O
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        Print "Execution cancelled." Ab%;Z5$fr  
        End $mm
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    End If 9j]sD/L5q  
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    'Assign accommodation and pupil diameter & use defaults if field left empty .roqEasu8  
    If dlg.TextBox1 = "" Then G&xo1K]  
        A = 0           'Default accommodation +x?#DH-  
    Else 4h!f/aF'  
        A = CDbl(dlg.TextBox1) 5ercD  
    End If heaRX4  
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    If dlg.TextBox2 = "" Then R3)57OyV  
        pupilDiam = 4   'Default pupil diameter l+V,DCE  
    Else 93+"D`  
        pupilDiam = CDbl(dlg.TextBox2) ;=j@, yu  
    End If 8(.mt/MR
 
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    Print " " =~Ynz7 /x  
    Print "Accommodation = " & A & " Diopters" pL1Q7&&c0  
    Print "Pupil Diameter = " & pupilDiam & " mm" n?\ nn3  
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    ' Calculate new parameters with accommodation n,eJ$2!J  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness &1l=X]%  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens RjF'x  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ONNpiK-  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens B/5=]R  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens IX: 25CEI2  
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    tlens = 3.767 + 0.04*A                  'Lens thickness }pk#!
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction l$K,#P<)  
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    'Adjust parameters to account for accommodation 6Ao%>;e*  
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    '************************************************************************* Tmh(= TB'  
    'Aqueous thickness (Position of Lens) _A<u#.yd  
    '************************************************************************* a9n^WOJ6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) VL[R(a6c <  
    GetCustomElement eID, entity ;fw1
 
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    parID = FindFullName( "Geometry.Arizona Eye" ) *5zrZ]^  
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    ' Delete any shift(s) in z Lb{e,JH  
    count = 0 2j(h+?N7k  
    While GetOperationCount(eID)>count nd;fy$<J\  
        GetOperation eID, count, op ,f}UGd[a  
        If op.Type="ShiftZ" Then -",=G\XZ  
            DeleteOperation eID,count vA$o~?a]/  
            count=count-1 K =.%$A  
        End If r1ws1 rr=  
        count=count+1 !R*-R.%  
    Wend =fm]Dl9h*  
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    'Set new shift in  $Vc~/>  
    op.Type = "ShiftZ" kc7l
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    op.val1 = taq =#mTfJ   
    op.parent = parID ]zO/A4  
    AddOperation eID, op .nYUL>  
    Print "Set aqueous humor thickness = " & taq-0.55 s5RjIa0$7  
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    '************************************************************************* >7!6nF3x,  
    'Radius and conic constant of anterior lens *lef=:&,,  
    '************************************************************************* axHK_1N{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^QuiH'  
    GetConic eID, entity, curv, conic \#68;)+=  
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    SetConic eID, entity, 1/Rant, CCant pV6d Id  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant J$~<V IX  
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    '************************************************************************* USN8N (  
    'Radius and conic constant of posterior lens 9%*wb`&  
    '************************************************************************* zEZLKWm9-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) JFgoN,xn  
    GetConic eID, entity, curv, conic /-6S{hl9Ne  
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    SetConic eID, entity, 1/Rpost, CCpost =AVgIv  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost lpH=2l$>?  
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    '************************************************************************* '0$?
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    'Lens thickness (Position of posterior lens surface) )2,eFNB#n  
    '************************************************************************* pZ#ap<|>I  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %4\
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    ' Delete any z-shift(s) zI~owK)%Z  
    count = 0 1FtM>&%4  
    While GetOperationCount(eID)>count n.hv!W0  
        GetOperation eID, count, op ~}K5#<  
        If op.Type="ShiftZ" Then i(?,6)9  
            DeleteOperation eID,count ]|_\x
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            count=count-1 X-Wz:NA  
        End If tNVV)C  
        count=count+1 zrVC8Wb  
    Wend ,G#.BLH cX  
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    'Set new z-shift qyHZ M}/  
    op.Type = "ShiftZ" ?Qb<-~~ j1  
    op.val1 = tlens kt4d;4n  
    op.parent = parID jL
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    AddOperation eID, op VF&Z%O3n  
    Print "Set lens thickness = " & tlens qo)?8kx>l  
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    '************************************************************************* @|a>&~xX  
    'Lens index of refraction "U.^lkN  
    '************************************************************************* &D%(~|'  
    eID = FindMaterial( "Lens" ) 7u\*_mrv  
    GetModelMaterial eID, mat ~)?  
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    mat.Nd = nlens `si#aU  
    SetModelMaterial eID, mat *&AfR8x_z  
    Print "Set lens index of refraction = " & nlens ylKmj
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    '************************************************************************* c:83LZ  
    'Pupil diameter -/]W+[  
    '************************************************************************* nN$Y(2ZN  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) XWJwJ  
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    'Adjust pupil diameter (trimming volume inner hole) @DW[Z`X
 
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5 ,0d  
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    ' Adjust pupil location to just in front of the lens @`FCiHM  
    parID = FindFullName( "Geometry.Arizona Eye" ) 3Rm#-T s  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) PNW \*;j  
    count = 0 4`#F^2r!  
    While GetOperationCount(eID)>count +7Kyyu)y@  
        GetOperation eID, count, op Hn,:`mj4-6  
        If op.Type="ShiftZ" Then )pw&c_x  
            DeleteOperation eID,count 0'&X T^"  
            count=count-1 LtT\z<bAI  
        End If bYe;b><G  
        count=count+1 BF{w)=@/'  
    Wend = sAn,ri  
    op.Type = "ShiftZ" zU6a'tP  
    op.val1 = taq-0.01 UEak^Mm;=2  
    op.parent = parID 3Q/#T1@  
    AddOperation eID, op JcJmds  
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    Print "Set pupil diameter = " & pupilDiam MH|]\  

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    'Update AZ Eye subassembly Description ch5s<x#CE  
    eID = FindFullName( "Geometry.Arizona Eye" ) 7z_;t9Y  
    GetEntity eID, entity \qi
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    entity.Description = "Accommodation = " & A & "D" L]a`"CH:a$  
    SetEntity eID, entity OT %nrzP  
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    Update Gf8s?l  
    Print "DONE!" 'H9=J*9oG  
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End Sub 3CTX -#)vS  
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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： OPpjuIRv  
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Accommodation = 4 Diopters \EoX8b}$b0  
Pupil Diameter = 4 mm I[o*RKT'"  
Set aqueous humor thickness = 2.81 w^K^I_2ge  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ]j>i.5  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 
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Set lens thickness = 3.927 fJjgq)9  
Set lens index of refraction = 1.42672 (_* wt]"'  
Set pupil diameter = 4 l? #xAZx&_  
DONE! -6Tk<W