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    [分享]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 sRo%=7Z  
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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。 [Y*p I&f  
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    模型 Og%qv Bj 6  
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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。 oj@B'j  
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    Table 1. AZ眼睛模型的定义
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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. j0o_``  
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    光源 B4GgR,P@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。 Fg Qd7p  
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    图1. 光源和提示信息使用
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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。 rjQV;kX>  
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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。 vgHMVzxj  
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    图2. 字母F光源的设定方法光 >!wX% QHH  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 6I72;e ^!  
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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。 P$Xig  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 <y\>[7Y  
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    图5. 视网膜重点采样规格设定
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    脚本 {G/4#r 2>  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: `K~300-hOb  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 +I5@Gys  
    余下的脚本计算与屈光度有关的所有参数。 4At%{E  
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    分析 5"c#O U  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 I/<aY*R4  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 C\j|+s  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. g03I<<|@  
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    Dim entity As T_ENTITY V"#ie Y n  
    Dim op As T_OPERATION 4W*52*'F,  
    Dim mat As T_MODELMATERIAL w{UVo1r:  
    Dim A As Double x}i:nLhL  
    Dim pupilDiam As Double p./zW )7+  
    Dim eID As Long - {>JF  
    Dim parID As Long B5~S&HQ?B6  
    Dim count As Integer "e0$/WQ6J  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  [:  
    Dim tlens As Double, nlens As Double CbVUz<  
    Dim curv As Double, conic As Double e]'ui<`  
    Dim ok As Long :,Q\!s!  
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    Sub Main SHOg,#mV  
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        '用户输入对话框 b<P9@h~:  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Q35$GFj"jD  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Pb]: i+c)  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 >u ,Ac:  
            OKButton 40,91,90,21 G<#9`  
            CancelButton 190,91,90,21 IC{\iwO/~c  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 %YlL-*7 L  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Kp'_lKW)]q  
        End Dialog b lP@Cn2  
        Dim dlg As UserDialog y>_lxLhmO#  
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        ok = Dialog (dlg) &q^\*<B.^  
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        If ok=0 Then    'cancel button was pressed y4PR&^l?g  
            Print "Execution cancelled." D>|m8-@]  
            End $l@nk@  
        End If LuM:dJ  
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        'Assign accommodation and pupil diameter & use defaults if field left empty NGcd  
        If dlg.TextBox1 = "" Then c>#T\AEkF  
            A = 0           'Default accommodation ?`bi8 Ck  
        Else wmAZ {  
            A = CDbl(dlg.TextBox1) umhg O.!  
        End If }:<`L\8q\  
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        If dlg.TextBox2 = "" Then 8/F}vfKEN  
            pupilDiam = 4   'Default pupil diameter UmUw>+A  
        Else <ZcJC+k  
            pupilDiam = CDbl(dlg.TextBox2) dmI~$*  
        End If [-5%[ty9X  
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        Print " " @M-i$ q[4  
        Print "Accommodation = " & A & " Diopters" 4r&DW'  
        Print "Pupil Diameter = " & pupilDiam & " mm" }'L7<_  
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        ' Calculate new parameters with accommodation XVr>\T4  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness E w#UlA:"v  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens %Xc50n2Z  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens W^#HR  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens zGzeu)d  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens dO]N&'P7  
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        tlens = 3.767 + 0.04*A                  'Lens thickness HHVCw7r0  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction [d 30mVM  
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        'Adjust parameters to account for accommodation #gn{X!;-;  
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        '************************************************************************* 0<tce  
        'Aqueous thickness (Position of Lens) O&BNhuW2  
        '************************************************************************* 7q\&  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Q^13KWvuV  
        GetCustomElement eID, entity O?\UPNb:K  
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        parID = FindFullName( "Geometry.Arizona Eye" ) BNi6I\wa  
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        ' Delete any shift(s) in z )(bAi  
        count = 0 = VIU  
        While GetOperationCount(eID)>count 4`E[ WE:Q  
            GetOperation eID, count, op Q /D?U[G  
            If op.Type="ShiftZ" Then N;Hoi8W  
                DeleteOperation eID,count ]hE%Tk-  
                count=count-1 a(.q=W  
            End If 1. A@5*Q  
            count=count+1 D+4oV6}~  
        Wend P+ ejyl,  
    '`s\_Q)hG_  
        'Set new shift in T{ WJf-pI  
        op.Type = "ShiftZ" /Ne;Kdp  
        op.val1 = taq CgT5sk}  
        op.parent = parID `-_kOxe3  
        AddOperation eID, op b'AA*v,b  
        Print "Set aqueous humor thickness = " & taq-0.55 ,4W~CkLD  
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        '************************************************************************* S<*h1}V3/  
        'Radius and conic constant of anterior lens FYBW3y+AF&  
        '************************************************************************* Z7]["  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) IKo,P$ PE  
        GetConic eID, entity, curv, conic GN1Q\8)o  
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        SetConic eID, entity, 1/Rant, CCant @kst G3@  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ]mzghH:E  
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        '************************************************************************* o?,c#g  
        'Radius and conic constant of posterior lens m!Y4+KTwD`  
        '************************************************************************* C>NLZM T  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 8kdJ;%^N  
        GetConic eID, entity, curv, conic \u4`6EYF?  
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        SetConic eID, entity, 1/Rpost, CCpost #'y4UN  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 5,_DM  
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        '************************************************************************* 7&`Yl[G  
        'Lens thickness (Position of posterior lens surface) P>}OwW  
        '************************************************************************* _^ZBSx09)  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) t~v_k\` {  
    L l$,"}0T  
        ' Delete any z-shift(s) YMG~k3Yb  
        count = 0 e6`g[Ap  
        While GetOperationCount(eID)>count Cfr2 ~w  
            GetOperation eID, count, op E !EENg  
            If op.Type="ShiftZ" Then pQ,|l$^m  
                DeleteOperation eID,count <`)vp0  
                count=count-1 V}aZ}m{J  
            End If Au10]b  
            count=count+1 byJR6f  
        Wend T`$!/BlZ  
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        'Set new z-shift 0<[g7BbR  
        op.Type = "ShiftZ" Um~DA  
        op.val1 = tlens Ir6(EIwx0  
        op.parent = parID Je*hyi7  
        AddOperation eID, op $Wn!vbL  
        Print "Set lens thickness = " & tlens u>\u}c  
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        '************************************************************************* ?Gnx!3Q  
        'Lens index of refraction +\x}1bNS%j  
        '************************************************************************* .Lm0$o*`  
        eID = FindMaterial( "Lens" ) \=2<< iv  
        GetModelMaterial eID, mat itmFZZh  
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        mat.Nd = nlens jn]:*i;i  
        SetModelMaterial eID, mat QTIC5cl,  
        Print "Set lens index of refraction = " & nlens { Ba_.]x  
    +.J/7 gD  
        '************************************************************************* O77^.B  
        'Pupil diameter 1|WrJ-Uf  
        '************************************************************************* !g[UFw  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) TCI)L}L|  
    jZgCDA8Mr!  
        'Adjust pupil diameter (trimming volume inner hole) *@eZt*_  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" G'T: l("l  
    Z,I0<ecaD  
        ' Adjust pupil location to just in front of the lens *&BS[0;  
        parID = FindFullName( "Geometry.Arizona Eye" ) '/F%  ff  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) }X9G(`N(}  
        count = 0 W`F?j-4  
        While GetOperationCount(eID)>count }B`T%(11=  
            GetOperation eID, count, op m%%\k \  
            If op.Type="ShiftZ" Then PI&@/+  
                DeleteOperation eID,count +>QD4z#  
                count=count-1 19;Pjo8  
            End If D[0g0>K  
            count=count+1 !BDJU  
        Wend =X3Rk)2r  
        op.Type = "ShiftZ" UT%?3}*u"  
        op.val1 = taq-0.01 B-oQjr-  
        op.parent = parID G2yQHTbl  
        AddOperation eID, op M*Ri1   
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        Print "Set pupil diameter = " & pupilDiam JN-W`2  
    s x2\  
        'Update AZ Eye subassembly Description x"~gulcz  
        eID = FindFullName( "Geometry.Arizona Eye" ) a 9!.e rM  
        GetEntity eID, entity !bBx'  
        entity.Description = "Accommodation = " & A & "D" 7OD2/{]5  
        SetEntity eID, entity AP9>_0=  
    M7.H;.?  
        Update J\E?rT  
        Print "DONE!" o&RNpP*  
         @ r/f  
    End Sub ~=t K17i  
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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: M)G|K a  
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    Accommodation = 4 Diopters &%;K_asV;  
    Pupil Diameter = 4 mm !h70<Q^  
    Set aqueous humor thickness = 2.81 Gj&`+!\  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 qS[KB\RN1  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 h| N!U/(U  
    Set lens thickness = 3.927 q|QkJr <  
    Set lens index of refraction = 1.42672 s:*" b'  
    Set pupil diameter = 4 ;:aCZ8e  
    DONE! 5GwzG<.\^_  
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    <P_B|Y4N/  
    QQ:2987619807 I(va;hG<o  
     
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