[技术]Arizona眼睛模型 [复制链接]

简介 ]@j"0F/`  
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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。 3<.j`JB@&  
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模型 /{#_Um0.  
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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。 rc{[\1 -N  
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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. LZAj4|~,m  
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光源 /j5- "<;.  
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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。 Q17o5##x7  
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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。 D 5wR?O  
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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。 r7BH{>-  
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视网膜的散射 %K f. F  
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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。 +Gwe%p Q  
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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。 $6x:aG*F  
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脚本 9
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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： W%<]_u[-}  
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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。 2bG4
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余下的脚本计算与屈光度有关的所有参数。 oZcwbo8  
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分析 6XCX#4'i%  
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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。 KGLhl;a  
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脚本代码 *RE-K36m|u  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. r@ *A  
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Dim entity As T_ENTITY @
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Dim op As T_OPERATION nVA'O  
Dim mat As T_MODELMATERIAL ?D 9#dGK  
Dim A As Double W%ZU& YBc  
Dim pupilDiam As Double IMw)X0z  
Dim eID As Long 0a
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Dim parID As Long }Fe{s;  
Dim count As Integer &>B>+}'
 
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double tSLl'XeN  
Dim tlens As Double, nlens As Double Z8n%=(He  
Dim curv As Double, conic As Double { RX|  
Dim ok As Long hg/&[/eodm  
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Sub Main (mr`?LI}  
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    '用户输入对话框 m)2hl~o_  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 s-S"\zX\D  
        TextBox 220,21,40,21,.TextBox1 'default: 0 MQMy Z:  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 $5(%M8qmQ  
        OKButton 40,91,90,21 
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        CancelButton 190,91,90,21 vX24W*7  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 #/=
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        TextBox 220,49,40,21,.TextBox2 'default: 4 #IA(*oM  
    End Dialog !0+Ex F  
    Dim dlg As UserDialog =zGz|YI*?  
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    ok = Dialog (dlg) ~7lvY+k)<  
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    If ok=0 Then    'cancel button was pressed K1nwv"  
        Print "Execution cancelled." qz SI cI  
        End }H^
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    End If -T6%3>h  
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    'Assign accommodation and pupil diameter & use defaults if field left empty `g1~ya(MC  
    If dlg.TextBox1 = "" Then u;1NhD<n  
        A = 0           'Default accommodation v
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    Else k~F/Ho+R&  
        A = CDbl(dlg.TextBox1) 3goJ(XI  
    End If `W S  
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    If dlg.TextBox2 = "" Then $X]v;B)J|  
        pupilDiam = 4   'Default pupil diameter X*):N]  
    Else /YR$#&N2  
        pupilDiam = CDbl(dlg.TextBox2) d0,F'?.0|  
    End If dPX>A4wp  
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    Print " " ,gD i)]  
    Print "Accommodation = " & A & " Diopters" 8{e 3  
    Print "Pupil Diameter = " & pupilDiam & " mm" Ik)Q0_<a  
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    ' Calculate new parameters with accommodation E:OeU_\  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness !A0bbJ  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #<3\}*/  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens A+8b]t_k  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 7QFEQ}  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ri`|qy6! |  
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    tlens = 3.767 + 0.04*A                  'Lens thickness __npX_4%S  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction v[GHqZ  
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    'Adjust parameters to account for accommodation r"
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    '************************************************************************* r2w7lf66!  
    'Aqueous thickness (Position of Lens) y9<Fv|Ric  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5}ah
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    GetCustomElement eID, entity $Yc9><i  
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    parID = FindFullName( "Geometry.Arizona Eye" ) _=#mmZkq  
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    ' Delete any shift(s) in z +(0eOO'\M  
    count = 0 EG6fC4rfC  
    While GetOperationCount(eID)>count #n r1- sf|  
        GetOperation eID, count, op h08T Q=n  
        If op.Type="ShiftZ" Then  5<poN)"  
            DeleteOperation eID,count HS9U.G>  
            count=count-1 k9]n/  
        End If KG@hjO  
        count=count+1 (""&$BJQ|  
    Wend s5e}X:  
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    'Set new shift in +>j_[O5Y  
    op.Type = "ShiftZ" vD t?N9  
    op.val1 = taq g^FH[(P[G  
    op.parent = parID ?=&*6H_v  
    AddOperation eID, op Sq>UMfl&  
    Print "Set aqueous humor thickness = " & taq-0.55 |Sm/Uq(c  
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    '************************************************************************* zT"#9"["  
    'Radius and conic constant of anterior lens x`&W[AA4  
    '************************************************************************* 5B6:pH6e  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ,@xZuq+K<  
    GetConic eID, entity, curv, conic t[Q\T0E  
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    SetConic eID, entity, 1/Rant, CCant Re_.<_$  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant SbY i|V,H  
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    '*************************************************************************
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    'Radius and conic constant of posterior lens l"/Os_4O  
    '************************************************************************* t)h3GM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) qI9 BAs1~}  
    GetConic eID, entity, curv, conic :O2N'vl47A  
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    SetConic eID, entity, 1/Rpost, CCpost = 4L.  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ?FyA2q!  
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    '************************************************************************* , {^g}d8  
    'Lens thickness (Position of posterior lens surface) p{Uro!J,K  
    '************************************************************************* xp= ]J UQ  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) -VL3em|0  
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    ' Delete any z-shift(s) }tN"C 3)@  
    count = 0 y$rp1||lH  
    While GetOperationCount(eID)>count c{[WOrA~#  
        GetOperation eID, count, op f`cO5lP/:)  
        If op.Type="ShiftZ" Then JXrMtSp\  
            DeleteOperation eID,count ?]S*=6  
            count=count-1 MFrVGEQBRL  
        End If zKo,B/Ke4  
        count=count+1 {dDU^7O  
    Wend [LE_lATjU  
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    'Set new z-shift U<$|ET'  
    op.Type = "ShiftZ" *:iFhKFU  
    op.val1 = tlens _ ._'\  
    op.parent = parID $|AxQQ%f  
    AddOperation eID, op ~_Aclm?  
    Print "Set lens thickness = " & tlens 0[^f9NZ>-  
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    '************************************************************************* L]Uy+[gg  
    'Lens index of refraction &12.
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    '************************************************************************* 0=NB[eG  
    eID = FindMaterial( "Lens" ) YIfbcR5  
    GetModelMaterial eID, mat yo5|~"yZY  
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    mat.Nd = nlens @>?&Mw\c  
    SetModelMaterial eID, mat (c;$^xZK  
    Print "Set lens index of refraction = " & nlens >Gkkr{s9  
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    '************************************************************************* i9Qx{f88  
    'Pupil diameter ffdyDUzQ  
    '************************************************************************* opKtSF|)  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) uXXwMc<p  
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    'Adjust pupil diameter (trimming volume inner hole) 4q2aVm  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" YkTEAI|i  
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    ' Adjust pupil location to just in front of the lens Jf2  
    parID = FindFullName( "Geometry.Arizona Eye" ) {C [7V{4(%  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 7P=j2;7 v  
    count = 0 pl5!Ih6  
    While GetOperationCount(eID)>count >k"/:g^t  
        GetOperation eID, count, op Pt E>08  
        If op.Type="ShiftZ" Then VgOj#Z?K  
            DeleteOperation eID,count 2|+**BxHD  
            count=count-1 5E$)Ip  
        End If ^$VOC>>9  
        count=count+1 Gt'%:9r  
    Wend ip~PF5  
    op.Type = "ShiftZ" J?HYN%  
    op.val1 = taq-0.01 vV8}>  
    op.parent = parID MbYAK-l.h  
    AddOperation eID, op m3,i{  
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    Print "Set pupil diameter = " & pupilDiam RV-
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    'Update AZ Eye subassembly Description B+ +:7!  
    eID = FindFullName( "Geometry.Arizona Eye" ) Ao2t=vg  
    GetEntity eID, entity ,u/GA<'#M  
    entity.Description = "Accommodation = " & A & "D" El,p}Bi.  
    SetEntity eID, entity al1Uf]xh  
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    Update [/xw5rO%  
    Print "DONE!" 7i`8 c =.  
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End Sub "YM)bc  
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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： np
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Accommodation = 4 Diopters ULj'DzlfH  
Pupil Diameter = 4 mm ex1bjM7  
Set aqueous humor thickness = 2.81 1 %K^(J;  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Qn_*(CSp  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 d H]'&&M  
Set lens thickness = 3.927 "*a^_tsT?i  
Set lens index of refraction = 1.42672 <GT&q <4w  
Set pupil diameter = 4 v<
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DONE! crG+BFi