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    [分享]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 ?%`Ph ?BZl  
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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。 TE;f*!  
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    模型 Oe x   
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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。 (V&8 WN  
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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. sVr|kvn2  
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    光源 )sW!s3>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。 Zo-,TKgY'  
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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。 gaQ E'qp>  
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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。 bl&9O  
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    图2. 字母F光源的设定方法光 b+q'xnA=>  
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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 ,"5HJA4  
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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。 Y@:l!4DI  
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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。 Q|P M6ta  
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    图5. 视网膜重点采样规格设定
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    脚本 VRgckh m  
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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: \ a7m!v  
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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。 *1!'ZfT;  
    余下的脚本计算与屈光度有关的所有参数。 I L7kpH+y  
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    分析 }5n\us  
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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。 *g %bdO  
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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 _VjaTw8iM  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. )MSCyPp5  
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    Dim entity As T_ENTITY w8~R=k  
    Dim op As T_OPERATION S&-F(#CF^  
    Dim mat As T_MODELMATERIAL #g@4c3um|  
    Dim A As Double o3\^9-jmp  
    Dim pupilDiam As Double |A,.mOT  
    Dim eID As Long cUP1Uolvn  
    Dim parID As Long \!jz1`]&{  
    Dim count As Integer fj['M6+wd  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double g"Hl 30o  
    Dim tlens As Double, nlens As Double ?D7zty+}^  
    Dim curv As Double, conic As Double p %.Adxx  
    Dim ok As Long 8 %?MRRK  
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    Sub Main 2Mq@5n  
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        '用户输入对话框 2"|7 YI  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 _1O .{O  
            TextBox 220,21,40,21,.TextBox1 'default: 0 J E5qR2VA  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 _a9oHg  
            OKButton 40,91,90,21 ^\ln8!;  
            CancelButton 190,91,90,21 b@=H$"  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 z79oj\&[  
            TextBox 220,49,40,21,.TextBox2 'default: 4 tUZfQ  
        End Dialog pO fw *lD  
        Dim dlg As UserDialog +:jv )4^O  
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        ok = Dialog (dlg) K$GQc"  
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        If ok=0 Then    'cancel button was pressed [>_zV.X  
            Print "Execution cancelled." _qk&W_u  
            End TG8U=9qt  
        End If gaNe\  
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        'Assign accommodation and pupil diameter & use defaults if field left empty S76MY&Vx23  
        If dlg.TextBox1 = "" Then pRxVsOb  
            A = 0           'Default accommodation DzA'MX  
        Else 8 l= EL7  
            A = CDbl(dlg.TextBox1) T*Ge67  
        End If (RrC<5"  
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        If dlg.TextBox2 = "" Then m+7%]$  
            pupilDiam = 4   'Default pupil diameter )+Z.J]$O-  
        Else @c"s6h&  
            pupilDiam = CDbl(dlg.TextBox2) {*g{9`   
        End If ]oz>/\!  
    @].!}tz  
        Print " " `'P&={p8  
        Print "Accommodation = " & A & " Diopters" 3}3b@:<  
        Print "Pupil Diameter = " & pupilDiam & " mm" sK9RViqF\  
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        ' Calculate new parameters with accommodation )K::WqR%w)  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 7@e}rh?N-|  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens z<^LY]  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens x./"SQ=R+  
    v@2@9/  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens [4bE"u  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens vg@5`U`^h  
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        tlens = 3.767 + 0.04*A                  'Lens thickness ?dv-`)S&  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction |/8!P Km  
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        'Adjust parameters to account for accommodation cD!E.2[  
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        '************************************************************************* yt,Ky8y1  
        'Aqueous thickness (Position of Lens) ./.aLTh  
        '************************************************************************* 5{iNR4sq  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #j+cl'  
        GetCustomElement eID, entity 3QVUWhJ  
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        parID = FindFullName( "Geometry.Arizona Eye" ) T*C F5S  
    5&_")k3$*  
        ' Delete any shift(s) in z r| \""  
        count = 0 9AQ,@xP|  
        While GetOperationCount(eID)>count L *|P'  
            GetOperation eID, count, op zLg$|@E&  
            If op.Type="ShiftZ" Then *<[\|L:#]Z  
                DeleteOperation eID,count TXV^f*  
                count=count-1 Ku uiU= (L  
            End If ea`6J  
            count=count+1 d ( ru5*p  
        Wend 9H:J&'Xi7  
    "H@I~X=  
        'Set new shift in 0yMHU[):~  
        op.Type = "ShiftZ" i-p,x0th  
        op.val1 = taq ZWjje6  
        op.parent = parID Bf+~&I#E  
        AddOperation eID, op M$>Nd6,@N  
        Print "Set aqueous humor thickness = " & taq-0.55 '^7UcgugB  
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        '************************************************************************* KyP@ hhj  
        'Radius and conic constant of anterior lens vo)W ziHh  
        '************************************************************************* Lc]hwMGR*  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;p <BiC$b  
        GetConic eID, entity, curv, conic oOubqx  
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        SetConic eID, entity, 1/Rant, CCant ePaC8sd0  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant <pKOFN%m  
    1;{nU.If  
        '************************************************************************* ~q/~ u  
        'Radius and conic constant of posterior lens Nr)DU.f  
        '************************************************************************* +u5xK  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 0Ny +NE:6M  
        GetConic eID, entity, curv, conic 8ql<7RTM!  
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        SetConic eID, entity, 1/Rpost, CCpost 7 TM-uA$  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Zn Rj}y  
    >){}nlQf  
        '************************************************************************* z-"P raP  
        'Lens thickness (Position of posterior lens surface) /!6 VP |  
        '************************************************************************* Al *yx_j  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) `jhbKgR[  
    10r!p: D  
        ' Delete any z-shift(s) @(N} {om  
        count = 0 LL+_zBP.   
        While GetOperationCount(eID)>count "qZTgCOY2  
            GetOperation eID, count, op 3|)cT1ej  
            If op.Type="ShiftZ" Then fT?m~W^  
                DeleteOperation eID,count $DnJ/hg;qD  
                count=count-1 as y:[r"  
            End If @ IDY7x27  
            count=count+1 JP ;SO  
        Wend 1sJz`+\  
    vtK.7AF  
        'Set new z-shift _pvt,pW  
        op.Type = "ShiftZ" ^AZv4H*~  
        op.val1 = tlens K9nW"0>  
        op.parent = parID HB.:/ 5\  
        AddOperation eID, op ^)|tf\4  
        Print "Set lens thickness = " & tlens ~qTChCXP  
    XI`s M~'  
        '*************************************************************************  zNn  
        'Lens index of refraction +~ Y.m8  
        '************************************************************************* Zk|PQfi+  
        eID = FindMaterial( "Lens" ) Y q|OX<i`K  
        GetModelMaterial eID, mat 6~?yn-Z  
    9>&p:+D  
        mat.Nd = nlens 'b>3:&  
        SetModelMaterial eID, mat 7[R`52pP  
        Print "Set lens index of refraction = " & nlens ).Iifu|ks  
    }y(cv}8Y  
        '************************************************************************* 7<2^8 `  
        'Pupil diameter SF ^$p$mC  
        '************************************************************************* @|OGxQoC  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ]]_c3LJ2`  
    C9FAX$$^(Y  
        'Adjust pupil diameter (trimming volume inner hole) #0^a-47PA<  
    {aopGu?i  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" q!h'rX=_-  
    lD# yXLaC\  
        ' Adjust pupil location to just in front of the lens rV-Xsf7Z  
        parID = FindFullName( "Geometry.Arizona Eye" ) Aaz:C5dtU  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) /:,}hy+U  
        count = 0 p"*xye x  
        While GetOperationCount(eID)>count G \$x.  
            GetOperation eID, count, op %_>8.7  
            If op.Type="ShiftZ" Then .H&XP W  
                DeleteOperation eID,count U:PtRSdn!b  
                count=count-1 <<@F{B7h  
            End If ys7 Tq+  
            count=count+1 2@N-#x '  
        Wend (&_~eYZU  
        op.Type = "ShiftZ" ]2@lyG#<<  
        op.val1 = taq-0.01 VjeF3pmBa  
        op.parent = parID =#{q#COK$  
        AddOperation eID, op rTST_$"_6  
    <Y;w I#C  
        Print "Set pupil diameter = " & pupilDiam &v:[+zw  
    :C&6M79k  
        'Update AZ Eye subassembly Description WK{F  
        eID = FindFullName( "Geometry.Arizona Eye" ) $g,v]MW  
        GetEntity eID, entity srKEtd"  
        entity.Description = "Accommodation = " & A & "D" VY=YI}E  
        SetEntity eID, entity UMPW<> z  
    tq*6]q8c>  
        Update :j32 :/u  
        Print "DONE!" '@^mesMG  
         rfh`;G5s  
    End Sub =66'33l2  
    4#B 56f8  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: _@_EQ!=  
    h=kC3ot\  
    Accommodation = 4 Diopters |#(y?! A^  
    Pupil Diameter = 4 mm t7e7q"+/  
    Set aqueous humor thickness = 2.81 uj)fah?Wg  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 oC3W_vH.%  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ~*tn|?%  
    Set lens thickness = 3.927 @qF:v]=_@  
    Set lens index of refraction = 1.42672 O6\c1ha  
    Set pupil diameter = 4 P_.AqEH  
    DONE! hij 9r z  
    rWN%j)#+  
    h5v=h>c  
    QQ:2987619807 m,rkKhXP  
     
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