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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 Sc{&h8KMTb  
    aPxSC>p  
    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。 v[uVAbfQ  
    H][TH2H1  
    模型 5lHt~hB\  
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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。 xSN;vrLHR  
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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. Ag0w8F  
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    光源 2H$](k?   
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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。 $=\=80u/  
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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。 no-";{c  
    -5og)ZGVUA  
    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。 83vZRQw  
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    图2. 字母F光源的设定方法光 y g(Na  
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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 YvG$2F|_)  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ~N9k8eT  
    M/W9"N[ta  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 P51cEhf  
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    图5. 视网膜重点采样规格设定
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    脚本 :1f,%Z$,q  
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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: ^~l@ _r  
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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。 _gK}Gi?|  
    余下的脚本计算与屈光度有关的所有参数。 [4qvQ7Y !  
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    分析 OF1^_s;  
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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。 pR0 !bgC  
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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 kygj" @EX  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. .DwiIr'  
    i88 5T '  
    Dim entity As T_ENTITY ;LC|1_ '  
    Dim op As T_OPERATION ![{/V,V]~  
    Dim mat As T_MODELMATERIAL )ty>{t  
    Dim A As Double 0?FJ ~pu  
    Dim pupilDiam As Double jm&[8ApW  
    Dim eID As Long 76[ qFz  
    Dim parID As Long ok,O/|E}?  
    Dim count As Integer `TF3Ho\MC  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double nY;Sk#9  
    Dim tlens As Double, nlens As Double ~,F]~|U7l  
    Dim curv As Double, conic As Double y<IHZq`C3  
    Dim ok As Long <au_S\n  
    C4X3;l Z%S  
    Sub Main %eHr^j~w$  
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        '用户输入对话框 p{qA%D  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 v^/<2/E"?4  
            TextBox 220,21,40,21,.TextBox1 'default: 0 K7x;/O  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 - ]We|{  
            OKButton 40,91,90,21 M4 ?>x[Pw  
            CancelButton 190,91,90,21 WB (?6"  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ZrP 8/>  
            TextBox 220,49,40,21,.TextBox2 'default: 4 a]V#mF |{  
        End Dialog o^uh3,.  
        Dim dlg As UserDialog GdScYAC   
    [4;_8-[Nv  
        ok = Dialog (dlg) c-7Zk!LfD  
    "E5=AW d  
        If ok=0 Then    'cancel button was pressed k=Wt57jt  
            Print "Execution cancelled." g~|x^d^;|  
            End Kzt:rhiB  
        End If 8PeVHpZ  
    =RWY0|f  
        'Assign accommodation and pupil diameter & use defaults if field left empty # NK{]H$fd  
        If dlg.TextBox1 = "" Then <#Fex'4  
            A = 0           'Default accommodation tg%<@U`7=  
        Else +N~{6*@uz,  
            A = CDbl(dlg.TextBox1)  .;vd  
        End If i)'u!V  
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        If dlg.TextBox2 = "" Then X2~KNw  
            pupilDiam = 4   'Default pupil diameter i7\>uni  
        Else +K=RMqM-8  
            pupilDiam = CDbl(dlg.TextBox2) 3!?QQT,!)  
        End If >9g^-~X;v  
    4Im}!q5;:<  
        Print " " E}36  
        Print "Accommodation = " & A & " Diopters" ;%>X+/.y0  
        Print "Pupil Diameter = " & pupilDiam & " mm" 0icB2Jm:D}  
    Ex}TDmTu  
        ' Calculate new parameters with accommodation FNl^ lj`Y  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness "tK3h3/Xv  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ~Ty6]A  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Jju?v2y`  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens zb9vUxN [  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Gv(n2r  
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        tlens = 3.767 + 0.04*A                  'Lens thickness !VfVpi+-  
    I= z+`o8  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction BIvz55g  
    ;ov}%t>UD  
        'Adjust parameters to account for accommodation x||b :2  
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        '************************************************************************* ,.gI'YPQC  
        'Aqueous thickness (Position of Lens) fG7-0 7  
        '************************************************************************* "bjbJC&T  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) )4+uM'2%  
        GetCustomElement eID, entity r^\Wo7q  
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        parID = FindFullName( "Geometry.Arizona Eye" ) ?N%5c%oF  
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        ' Delete any shift(s) in z :~,akX$  
        count = 0 61TL]S8  
        While GetOperationCount(eID)>count y2C/DyuAY|  
            GetOperation eID, count, op RQn3y-N]  
            If op.Type="ShiftZ" Then 4MgG]  
                DeleteOperation eID,count PzLV}   
                count=count-1 #|e5i9l*B  
            End If 69C ss'  
            count=count+1 -g vS 3`lX  
        Wend Od]wh  
    %A( hmC  
        'Set new shift in yD ur9Qd6  
        op.Type = "ShiftZ" t2%gS" [  
        op.val1 = taq kZ 9n@($B  
        op.parent = parID k1WyV_3  
        AddOperation eID, op 7.v{=UP  
        Print "Set aqueous humor thickness = " & taq-0.55 A'? W5~F  
    v-Uz,3  
        '************************************************************************* VzFzVeJ  
        'Radius and conic constant of anterior lens 0h2MmI#  
        '************************************************************************* E!>l@ ki  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) x\(yjNZH  
        GetConic eID, entity, curv, conic &sPu 3.p  
    QjUojHz%Z  
        SetConic eID, entity, 1/Rant, CCant =0mGfT c  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant $Jj0%?;  
    c6pGy%T-  
        '************************************************************************* !]WC~#|{B  
        'Radius and conic constant of posterior lens CQ%yki  
        '************************************************************************* $U5$*R@jo[  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) QnDLSMx)  
        GetConic eID, entity, curv, conic <Xj ,>2m;  
    2HvzMo-4  
        SetConic eID, entity, 1/Rpost, CCpost X 7"hTD  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9!6yo  
    04<T2)QgK  
        '************************************************************************* b(gcnSzM2  
        'Lens thickness (Position of posterior lens surface) u&Dd9kMz  
        '************************************************************************* F30jr6F\  
    Bc y$"F|r  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) -wV0Nv(V8  
    @-qC".CI  
        ' Delete any z-shift(s) Y~bGgd]T  
        count = 0 I*)eP||  
        While GetOperationCount(eID)>count Z})n%l8J]p  
            GetOperation eID, count, op 4&LoE~  
            If op.Type="ShiftZ" Then lf9_!`DGV  
                DeleteOperation eID,count GB_ m&t  
                count=count-1 } "ts  
            End If oWc +i U(  
            count=count+1 #3u471bp  
        Wend pNzGpCk  
    :WnXoL  
        'Set new z-shift C(*)7| m  
        op.Type = "ShiftZ" IyA8+N y  
        op.val1 = tlens 4) nQBFX  
        op.parent = parID 8M'6Kcr  
        AddOperation eID, op &gR)bNIC_=  
        Print "Set lens thickness = " & tlens w]0jq U6  
    Jid:$T>  
        '************************************************************************* Q,`Y  
        'Lens index of refraction +#<"o#gZ  
        '************************************************************************* {*C LWs4  
        eID = FindMaterial( "Lens" ) a?!Joi[  
        GetModelMaterial eID, mat s2ys>2k  
    FR@ dBcJUU  
        mat.Nd = nlens [}_ar  
        SetModelMaterial eID, mat |KC3^  
        Print "Set lens index of refraction = " & nlens G1'w50Yu  
    r4qFEFV3%  
        '************************************************************************* 5+O#5" v_  
        'Pupil diameter _?2xIo  
        '************************************************************************* :+,qvu!M7  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ),6Z1 K1  
    rbP3&L  
        'Adjust pupil diameter (trimming volume inner hole) vu.f B4  
    6A/|XwfE/v  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" /(nA)V( :  
    zj;y`ENj  
        ' Adjust pupil location to just in front of the lens 9aC>gye!  
        parID = FindFullName( "Geometry.Arizona Eye" ) t>v']a +k  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 3-8Vw$u  
        count = 0 BWX&5""  
        While GetOperationCount(eID)>count 4p~:(U[q  
            GetOperation eID, count, op e"|9%AW@<  
            If op.Type="ShiftZ" Then 5y"yd6O]O5  
                DeleteOperation eID,count Ahq^dx#o  
                count=count-1 X6<HNLgra  
            End If }Gz"og*8  
            count=count+1 ^HL#)fK2I  
        Wend T "G!H  
        op.Type = "ShiftZ" *qBMt[a  
        op.val1 = taq-0.01 knBT(x'+  
        op.parent = parID a}c(#ZLs  
        AddOperation eID, op T+4Musu{V  
    4!gyFi6$  
        Print "Set pupil diameter = " & pupilDiam  D#m+w  
    %NS]z;G  
        'Update AZ Eye subassembly Description ,?#-1uIGL>  
        eID = FindFullName( "Geometry.Arizona Eye" ) 28BiuxVW  
        GetEntity eID, entity |#2<4sd  
        entity.Description = "Accommodation = " & A & "D" Qw5M\   
        SetEntity eID, entity SqTm/ t  
    6U+#ADo  
        Update +ic~Sar  
        Print "DONE!" G:e}>'  
         sfrh+o57  
    End Sub 6OTxtk  
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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: |k+&we uY  
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    Accommodation = 4 Diopters ;LrKXp  
    Pupil Diameter = 4 mm nQ(#'9  
    Set aqueous humor thickness = 2.81 dF.T6b  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 (x$k\H  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 *BO4"3Z  
    Set lens thickness = 3.927 WAdl@){  
    Set lens index of refraction = 1.42672 &1':s|c  
    Set pupil diameter = 4 [7s5Vt|  
    DONE! P|(J]/  
    #uXOyiE  
    D@JHi'F  
    QQ:2987619807 !7 ^He3  
     
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