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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 %6HDLG6@^}  
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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。 ?< mSEgvu  
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    模型 @~xNax&^  
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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。 mRFcZ.7  
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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. 5&\Q0SX(~  
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    光源 ~~]L!P  
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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。 SX$v&L<  
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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。 ;}ileL Tl  
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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。 ]8<;,}#  
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    图2. 字母F光源的设定方法光 c4k3|=f  
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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 z;x $tO  
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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。 KAT4C 4=,  
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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。 jqh d<w  
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    图5. 视网膜重点采样规格设定
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    脚本 2xN1=ug  
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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: D9*GS_K2 t  
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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。 Ph'*s{   
    余下的脚本计算与屈光度有关的所有参数。 %qfql  
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    分析 SxdH %agM  
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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。 > SU2Jw  
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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 K3Zc>QL{  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 9 ,=7Uh#7  
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    Dim entity As T_ENTITY \BOZhXfl'  
    Dim op As T_OPERATION p,.+i[V  
    Dim mat As T_MODELMATERIAL BWamF{\d1a  
    Dim A As Double d h#4/Wa,  
    Dim pupilDiam As Double k>I[U}h  
    Dim eID As Long &=oW=g2  
    Dim parID As Long S-&[Tp+N  
    Dim count As Integer :Y`cgi0vkd  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double g} 7FR({b  
    Dim tlens As Double, nlens As Double CZcn X8P'8  
    Dim curv As Double, conic As Double +P2f<~  
    Dim ok As Long Bvj-LT=)  
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    Sub Main gs wp:82e2  
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        '用户输入对话框 .]}kOw:(#  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 # Y/ .%ch.  
            TextBox 220,21,40,21,.TextBox1 'default: 0 P~$FgAV  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 MQ>.^]B]o  
            OKButton 40,91,90,21 l=G=J(G  
            CancelButton 190,91,90,21 bU9B2'%E  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 b0|q@!z>  
            TextBox 220,49,40,21,.TextBox2 'default: 4 uKHkC.g  
        End Dialog o_>id^$>B  
        Dim dlg As UserDialog /*\pm!]._^  
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        ok = Dialog (dlg) b37P[Q3  
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        If ok=0 Then    'cancel button was pressed d5mhk[p7\J  
            Print "Execution cancelled." *)+1BYMo  
            End iLiEh2%P  
        End If *vqlY[2Ax  
    EkS7j>:  
        'Assign accommodation and pupil diameter & use defaults if field left empty YcW[BMy5h  
        If dlg.TextBox1 = "" Then '# K:e  
            A = 0           'Default accommodation SZW+<X  
        Else C,T9xm  
            A = CDbl(dlg.TextBox1) {a -bew  
        End If &(a#I]`9M  
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        If dlg.TextBox2 = "" Then h >V8YJ  
            pupilDiam = 4   'Default pupil diameter c#X9d8>  
        Else \-3\lZ3qj  
            pupilDiam = CDbl(dlg.TextBox2) | d}f\a`  
        End If LnZzY0  
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        Print " " }? j>V  
        Print "Accommodation = " & A & " Diopters" 8Yfg@"Tn  
        Print "Pupil Diameter = " & pupilDiam & " mm" z'N_9=  
    ?0k(wiF  
        ' Calculate new parameters with accommodation [C 1o9c!  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness uJ ;7]  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Z'sAu#C  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens dm;H0v+Y'  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens *((wp4b  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens q2v:lSFY  
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        tlens = 3.767 + 0.04*A                  'Lens thickness {.c(Sw}Eo  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ;4XvlcGo  
    :.5l9Ci4  
        'Adjust parameters to account for accommodation tj:3R$a  
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        '************************************************************************* 34S|[PX d  
        'Aqueous thickness (Position of Lens) *xm(K +j  
        '************************************************************************* u;1/.`NPB  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) # D8Z~U,-  
        GetCustomElement eID, entity TS0x8,'$q  
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        parID = FindFullName( "Geometry.Arizona Eye" ) zO#{qF+~;  
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        ' Delete any shift(s) in z Nu !(7  
        count = 0 hT:+x3  
        While GetOperationCount(eID)>count J[E_n;d1  
            GetOperation eID, count, op %jaB>4.A:  
            If op.Type="ShiftZ" Then B&^WRM;7t  
                DeleteOperation eID,count cBICG",TA  
                count=count-1 m8KJ~02l#  
            End If yKE[,"  
            count=count+1 0Y rdu,c  
        Wend 'u@_4wWp  
    ^`b&fb v  
        'Set new shift in |Z%I3-z_DS  
        op.Type = "ShiftZ" }$DLa#\-  
        op.val1 = taq [Xp{z tGE  
        op.parent = parID _isqk~ ul  
        AddOperation eID, op ua$H"(#c  
        Print "Set aqueous humor thickness = " & taq-0.55 }1]E=!?)&  
    HQi57QB  
        '************************************************************************* Nda,G++5(  
        'Radius and conic constant of anterior lens rMDo5Z2  
        '************************************************************************* Lg[v-b=?I  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) DG_tmDT4  
        GetConic eID, entity, curv, conic R Wa4O#  
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        SetConic eID, entity, 1/Rant, CCant :00 #l]g0q  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant rBBA`Ut@F  
    x!\FB.h4!(  
        '************************************************************************* dc#Db~v}k  
        'Radius and conic constant of posterior lens +uR|0Jo8X  
        '************************************************************************* uP,{yna(  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) rEI]{?eoF  
        GetConic eID, entity, curv, conic Z2z"K<Z W  
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        SetConic eID, entity, 1/Rpost, CCpost  =[Lo9Sg  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost -fF1vJ7L  
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        '************************************************************************* }7k!>+eQ  
        'Lens thickness (Position of posterior lens surface)  & t b  
        '************************************************************************* _ED,DM  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) &{B-a  
    z4l O  
        ' Delete any z-shift(s) RG(m:N  
        count = 0 RusC5\BUX  
        While GetOperationCount(eID)>count V\axOz!  
            GetOperation eID, count, op ibDMhW$n  
            If op.Type="ShiftZ" Then 5j(3pV`_  
                DeleteOperation eID,count ]:* 8 Mb#  
                count=count-1 Qxds]5WB/  
            End If aQax85  
            count=count+1 Q;O\tl  
        Wend F",]*> r  
    :SxOQ(n  
        'Set new z-shift UN`F|~@v  
        op.Type = "ShiftZ" U^_'e_)  
        op.val1 = tlens 75Xi%mlE7  
        op.parent = parID "cerg?ix  
        AddOperation eID, op Q(lj &!?1k  
        Print "Set lens thickness = " & tlens VdpkE0  
    ?f+w:FO  
        '************************************************************************* U\S%Jq*  
        'Lens index of refraction 1j*I`xZ  
        '************************************************************************* fn|l9k~<O  
        eID = FindMaterial( "Lens" ) %gd=d0vm  
        GetModelMaterial eID, mat I\R5Cb<p  
    1jZ:@M :  
        mat.Nd = nlens 66\0JsT?3  
        SetModelMaterial eID, mat f~Dl;f~H_;  
        Print "Set lens index of refraction = " & nlens { .KCK_ d  
    u>;#.N/  
        '************************************************************************* H[o'j@0  
        'Pupil diameter yhr\eiJ@6  
        '************************************************************************* bhXH<=  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) `Rj<qz^7  
    ]Jj\**  
        'Adjust pupil diameter (trimming volume inner hole) sg 12C  
    gF% lwq  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" UTQ$sg|7p  
    cOUsbxYTD  
        ' Adjust pupil location to just in front of the lens Du>dTi~  
        parID = FindFullName( "Geometry.Arizona Eye" ) owe362q  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) AqVTHyCu  
        count = 0 'l\V{0;mp  
        While GetOperationCount(eID)>count woZ'T  
            GetOperation eID, count, op uR"srn;^  
            If op.Type="ShiftZ" Then `>RJ*_aKEI  
                DeleteOperation eID,count .<v0y"amJ  
                count=count-1 ^DHFP-G?e  
            End If dQ^>,(  
            count=count+1 x]%e_  
        Wend ?8Cxt|o>  
        op.Type = "ShiftZ" Kzxzz6R?  
        op.val1 = taq-0.01 !lE (!d3M  
        op.parent = parID ]+[ NX)=  
        AddOperation eID, op y]=v+Q*+  
    zQ xZR}'  
        Print "Set pupil diameter = " & pupilDiam P,!W\N%3  
    o_U=]mEDY  
        'Update AZ Eye subassembly Description MoA2Cp;8X  
        eID = FindFullName( "Geometry.Arizona Eye" ) h 88iZK  
        GetEntity eID, entity .hgc1  
        entity.Description = "Accommodation = " & A & "D" 1rC8] M.N  
        SetEntity eID, entity q /|<>s  
    n6WSTh  
        Update AW6]S*rh  
        Print "DONE!" WX 79V  
         ltt%X].[  
    End Sub ))!Z2PfD  
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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: Kv+E"2d  
    u7@|fND 7  
    Accommodation = 4 Diopters ~/[cZY @  
    Pupil Diameter = 4 mm df#DKV:  
    Set aqueous humor thickness = 2.81 !'ajpK  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 1*?IDYB  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 PiI ):B>  
    Set lens thickness = 3.927 'O]_A57  
    Set lens index of refraction = 1.42672 ,e>C)wq;  
    Set pupil diameter = 4 5gI@~h S  
    DONE! EBw}/y{Kt  
    -'{ioHt&X/  
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