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    [技术]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: 2021-10-22
    简介 'mY,>#sT  
    83 ^,'Z  
    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。 2YP"nj#  
    ZC\.};.  
    模型 c_8mQ  
    X-2S*L'  
    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。 %N_S/V0`  
    !^"!fuoNC  
    Table 1. AZ眼睛模型的定义
    |@bNd7=2d  
    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. O'sr[  
    .]P;fCQmM  
    光源 BQfAen]  
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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。 X=c ,`&^  
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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。 `R=_t]ie  
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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。 &8YI)G%  
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    图2. 字母F光源的设定方法光 'N,NG$G2  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 2dJ)4  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 WF.$gBH"  
    ]( 6vG$\  
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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。 ia.B@u1/  
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    图5. 视网膜重点采样规格设定
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    脚本  G/;aZ  
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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: I8wVvs;k  
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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。 :v ~q  
    余下的脚本计算与屈光度有关的所有参数。 @uD{`@[  
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    分析 mP+yjRw  
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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。 H LGy"P  
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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 xJ5!` #=  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. JU+'UK630  
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    Dim entity As T_ENTITY l:}4 6%  
    Dim op As T_OPERATION $ !=:ES  
    Dim mat As T_MODELMATERIAL HBGA lZ  
    Dim A As Double k}qiIMdI  
    Dim pupilDiam As Double *dgN pJ 9  
    Dim eID As Long |^!@  
    Dim parID As Long 4=cq76  
    Dim count As Integer ZJM^P'r.1c  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double xGk4KcxKs  
    Dim tlens As Double, nlens As Double ^C T}i'  
    Dim curv As Double, conic As Double "b7C0NE  
    Dim ok As Long '" yl>"  
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    Sub Main yt,;^o^  
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        '用户输入对话框 Jx?>1q=M  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ;Nij*-U4~  
            TextBox 220,21,40,21,.TextBox1 'default: 0 z|H>jit+  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ?Qk#;~\yB  
            OKButton 40,91,90,21 OO>2oH  
            CancelButton 190,91,90,21 Gjr2]t;E  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 [hbIv   
            TextBox 220,49,40,21,.TextBox2 'default: 4 ij5YV3  
        End Dialog D3ad2vH  
        Dim dlg As UserDialog uD3_'a  
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        ok = Dialog (dlg) {Wo7=aR  
    pXa? Q@ 6  
        If ok=0 Then    'cancel button was pressed V;(LeuDH|  
            Print "Execution cancelled." "dTXT  
            End 2=EKAg=S  
        End If -}o;Y)  
    ~O-8h0d3  
        'Assign accommodation and pupil diameter & use defaults if field left empty ?f&I"\y  
        If dlg.TextBox1 = "" Then ow "Xv  
            A = 0           'Default accommodation >Z% `&D~u  
        Else 63=m11 Z4  
            A = CDbl(dlg.TextBox1) K-3 _4As  
        End If g=Di2j{A  
    /jD'o>  
        If dlg.TextBox2 = "" Then 3I+pe;  
            pupilDiam = 4   'Default pupil diameter 605|*(  
        Else (6nw8vQ  
            pupilDiam = CDbl(dlg.TextBox2) >.|gmo>b  
        End If r;z A `  
    L%FL{G  
        Print " " }T,uw8?f!  
        Print "Accommodation = " & A & " Diopters" O;2 u1p'iP  
        Print "Pupil Diameter = " & pupilDiam & " mm" /eQn$ZRP,  
    >q`X%&l_  
        ' Calculate new parameters with accommodation 'Nh^SbD+_|  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness |k+^D:  
    @^O ww(I  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens h.*|4;  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens P*>V6SK>b  
    #82B`y<<y/  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 7nmo p7  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens i(WWF#N 5  
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        tlens = 3.767 + 0.04*A                  'Lens thickness :R)IaJ6)  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 9L};vkYk#  
    o#i {/# oF  
        'Adjust parameters to account for accommodation (k?OYz]c  
    c\Dv3bF  
        '************************************************************************* Z(L>~+%  
        'Aqueous thickness (Position of Lens) [# :k3aFz  
        '************************************************************************* /y}  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) nMhc3t  
        GetCustomElement eID, entity DsoF4&>g[B  
    yC[}gHv  
        parID = FindFullName( "Geometry.Arizona Eye" ) *4ID$BmO  
    Sz =z TPnO  
        ' Delete any shift(s) in z ?g'l/xuRe  
        count = 0 /vu7;xVG  
        While GetOperationCount(eID)>count `)'YU^s  
            GetOperation eID, count, op b#sO1MXv  
            If op.Type="ShiftZ" Then KLX>QR@  
                DeleteOperation eID,count z8o Sh t`+  
                count=count-1 v[m>;Ubg&  
            End If {0?76|  
            count=count+1 FX{Sb"  
        Wend ||hd(_W8  
    ~Y{K ^:wN^  
        'Set new shift in L(.5:&Y=`  
        op.Type = "ShiftZ" J&Ah52  
        op.val1 = taq [8ih-k  
        op.parent = parID JH 8^ZP:d'  
        AddOperation eID, op o!Y7y1$  
        Print "Set aqueous humor thickness = " & taq-0.55 % 74}H8q_z  
    Na4\)({  
        '************************************************************************* N)QW$iw9  
        'Radius and conic constant of anterior lens L!\I>a5C0G  
        '************************************************************************* 'Ag?#vB  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) L~\Ir  
        GetConic eID, entity, curv, conic _T1|_9b  
    _f/6bpv  
        SetConic eID, entity, 1/Rant, CCant yJ?6BLJi  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant d;K,2  
    {Wt=NI?Ow  
        '************************************************************************* LqNsQu";  
        'Radius and conic constant of posterior lens WmeV[iI  
        '************************************************************************* L:7%Wdyh  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) zpJQ7hym  
        GetConic eID, entity, curv, conic y6f YNB  
    *5u0`k^j  
        SetConic eID, entity, 1/Rpost, CCpost [&51m^  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost A\LMmg  
    d-y8c  
        '************************************************************************* V3 2F  
        'Lens thickness (Position of posterior lens surface) Lc=t,=OhGe  
        '************************************************************************* ?|kwYA$4o  
    r[K%8Y8`  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) a0~LZQ?  
    ka0MuQ M  
        ' Delete any z-shift(s) @kd`9Yw  
        count = 0 0.+MlyA  
        While GetOperationCount(eID)>count ]V^ >aUlj  
            GetOperation eID, count, op MaN6bM  
            If op.Type="ShiftZ" Then x.8fxogz  
                DeleteOperation eID,count DZ"'GQSg  
                count=count-1 {\hjKP  
            End If 1 8%+ Hy=  
            count=count+1 Qco8m4n  
        Wend JV ydTvc  
    IK1'" S|  
        'Set new z-shift 2{|Z?3FJ^  
        op.Type = "ShiftZ" !y+uQ_IS@  
        op.val1 = tlens -Gy=1W`09  
        op.parent = parID gWQ(B  
        AddOperation eID, op OY Sq)!:  
        Print "Set lens thickness = " & tlens :er(YWF:  
    ,<k%'a!B  
        '************************************************************************* L>LIN 1A  
        'Lens index of refraction ?zex]!R  
        '************************************************************************* xpX<iT>5u  
        eID = FindMaterial( "Lens" ) y 4U|~\]  
        GetModelMaterial eID, mat  LAkBf  
    DL`8qJ'mJs  
        mat.Nd = nlens :{+~i.*  
        SetModelMaterial eID, mat k3K*{"z  
        Print "Set lens index of refraction = " & nlens 0<7sM#sI!  
    4sRM" w;  
        '************************************************************************* Idb*,l|<  
        'Pupil diameter {n|ah{_p|  
        '************************************************************************* rY 6x):sC  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) elAWQEu s  
    a*-9n-U@[k  
        'Adjust pupil diameter (trimming volume inner hole) 7HkFDI()1  
    d(|q&b:  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 6se8`[  
    ]!ox2m_U  
        ' Adjust pupil location to just in front of the lens cI P.5)Ca  
        parID = FindFullName( "Geometry.Arizona Eye" ) & XmaGtt  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]XU4nNi  
        count = 0 hs[x\:})/  
        While GetOperationCount(eID)>count =WjHf8v;  
            GetOperation eID, count, op +}O -WX?  
            If op.Type="ShiftZ" Then 1^LdYO?g'  
                DeleteOperation eID,count u"q5 6}Q?]  
                count=count-1 <Xl#}6II  
            End If w+/`l*  
            count=count+1 kN.;;HFq#  
        Wend arDl2T,igF  
        op.Type = "ShiftZ" Rjq Xz6  
        op.val1 = taq-0.01 yI 2UmhA  
        op.parent = parID g35!a<JW  
        AddOperation eID, op z3y{0<3  
    *mzi ?3  
        Print "Set pupil diameter = " & pupilDiam `*Yw-HL  
    !{g<RS( c  
        'Update AZ Eye subassembly Description B~w$j/sWU  
        eID = FindFullName( "Geometry.Arizona Eye" ) S[1<Qrv]  
        GetEntity eID, entity sqrLys_S  
        entity.Description = "Accommodation = " & A & "D" qtExd~E  
        SetEntity eID, entity M@R"-$Z  
    A#. %7S  
        Update @khFk.LBD  
        Print "DONE!" x="Wqcnj{  
         <{isWEW9]3  
    End Sub Y~AjcqS  
    m+0yf(w  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: itg_+%^R  
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    Accommodation = 4 Diopters ob\-OMNs@  
    Pupil Diameter = 4 mm n9'3~qVZ  
    Set aqueous humor thickness = 2.81 p?i.<Z  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ( zWBrCX  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 sp,-JZD  
    Set lens thickness = 3.927 J#I RbO)  
    Set lens index of refraction = 1.42672 ij ?7MP  
    Set pupil diameter = 4 .xN<<+|_v'  
    DONE! g'7E6n"!,  
     
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