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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 > J>|+W  
    R'1L%srTM+  
    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。 |?Bb{Es  
    pSh$#]mZ`  
    模型 l5fF.A7TT  
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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。 n9N '}z  
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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. ("-`Y'"K  
    k:k!4   
    光源 6kM'f}t[C  
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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。 2i_X{!0}  
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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。 {_<,5)c  
    J0a#QvX!  
    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。 r]'Q5l4j6"  
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    图2. 字母F光源的设定方法光 v'W`\MKY)  
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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 2*1FW v  
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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。 KXTx{R  
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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。 J~URv)g  
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    图5. 视网膜重点采样规格设定
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    脚本  e+=IGYC  
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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: zA?]AL(+YW  
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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。 8NS1*\z  
    余下的脚本计算与屈光度有关的所有参数。 NDaM;`  
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    分析 aA/.EAc7  
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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。 YDMimis\H5  
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    图7. 字母F在视网膜上颜色分析
    ' y9yx[P  
    脚本代码 <DjFMTCN  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. :$"L;"  
    1S26Y|L)  
    Dim entity As T_ENTITY zrJ/Fs+s  
    Dim op As T_OPERATION z}[qk:  
    Dim mat As T_MODELMATERIAL umo@JWr  
    Dim A As Double wWNHZ v&  
    Dim pupilDiam As Double H!NyM}jsr  
    Dim eID As Long Xu8_<%  
    Dim parID As Long 8Qg,UX  
    Dim count As Integer c#6g[TE@  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double g@jAIy]  
    Dim tlens As Double, nlens As Double B "z`X!\  
    Dim curv As Double, conic As Double L)LW5%.6  
    Dim ok As Long *4tJ|m6"Y6  
    )KLsa`RV:  
    Sub Main  `=h`:`  
    Wqu][Wa[Z  
        '用户输入对话框 NHCdf*  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 - ^sbf.  
            TextBox 220,21,40,21,.TextBox1 'default: 0 =tv,B3Mo  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Pkbx /\  
            OKButton 40,91,90,21 8,,$C7"EP  
            CancelButton 190,91,90,21 8C{mV^cn~  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 DGwN*>X  
            TextBox 220,49,40,21,.TextBox2 'default: 4 z$>_c "D  
        End Dialog x{X(Y]*1S  
        Dim dlg As UserDialog &l=%*`On  
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        ok = Dialog (dlg) 9p#Laei].  
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        If ok=0 Then    'cancel button was pressed AIvIQ$6}  
            Print "Execution cancelled." K;u<-?En  
            End {5=Iu\e  
        End If bJo)rM :m  
    SJtQK-%wK>  
        'Assign accommodation and pupil diameter & use defaults if field left empty bnz2\C9^  
        If dlg.TextBox1 = "" Then G' ~Z'  
            A = 0           'Default accommodation D9;2w7v  
        Else &_^t$To  
            A = CDbl(dlg.TextBox1) >h0iq  
        End If cVt MCgx  
    3+_ .I{  
        If dlg.TextBox2 = "" Then &;%z1b> F  
            pupilDiam = 4   'Default pupil diameter 1N_Gk&  
        Else swBgV,;   
            pupilDiam = CDbl(dlg.TextBox2) Nd.+Rs  
        End If .X;zEyd  
    3Ms ` ajJ  
        Print " " kgX"LQh;[G  
        Print "Accommodation = " & A & " Diopters" +P?!yH,n  
        Print "Pupil Diameter = " & pupilDiam & " mm" (3DjFT3 w  
    Zr0bVe+h  
        ' Calculate new parameters with accommodation Gk9Y{  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ^T[8j/9o^  
    y\DR,$Py  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens +0016UgS#  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens R#ABda9  
    6q[|U_3I@  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens (5s$vcK  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 0^41dfdE  
    2nW:|*:/p6  
        tlens = 3.767 + 0.04*A                  'Lens thickness lLO|,  
    gBzg'Z  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction [*<F   
    `.dX@<  
        'Adjust parameters to account for accommodation }Km+5'G'U  
    YRXXutm  
        '************************************************************************* uT'}_2=:  
        'Aqueous thickness (Position of Lens) g-0?8q5T6  
        '************************************************************************* Wj"\nT4  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^t&S?_DSZ  
        GetCustomElement eID, entity CbmT aEaP  
    "+oP((9  
        parID = FindFullName( "Geometry.Arizona Eye" ) )[d?&GK  
    l^ P[nQDH  
        ' Delete any shift(s) in z ,m| :U  
        count = 0 ~c&ygL3  
        While GetOperationCount(eID)>count si:p98[w  
            GetOperation eID, count, op "HCJ!  
            If op.Type="ShiftZ" Then >wz& {9ni  
                DeleteOperation eID,count tC0:w,C)  
                count=count-1 "P) f,n  
            End If LUGyc( h  
            count=count+1 Zl5cHejM  
        Wend I}djDtJ  
    v~f_~v5J!  
        'Set new shift in k8 !|WqfP  
        op.Type = "ShiftZ" b&AGVWhh  
        op.val1 = taq !~+"TI}_%w  
        op.parent = parID  pFfd6P  
        AddOperation eID, op {E6M_qZ  
        Print "Set aqueous humor thickness = " & taq-0.55 @>Y.s6a  
    !c}?u_Z/  
        '************************************************************************* 4e6x1`Y{xB  
        'Radius and conic constant of anterior lens td*1  
        '************************************************************************* J!O{.v  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) C|#GODA  
        GetConic eID, entity, curv, conic Y>Oh]?  
    k9>2d'Q  
        SetConic eID, entity, 1/Rant, CCant N03)G2  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant b@GL*Z  
    Rra3)i`*  
        '************************************************************************* 9 7/"5i9  
        'Radius and conic constant of posterior lens }HO3D.HE^  
        '************************************************************************* _[D6 WY+  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) (v<l9}!  
        GetConic eID, entity, curv, conic 6n[O8^  
    d']CBoK  
        SetConic eID, entity, 1/Rpost, CCpost !*[Fw1-J  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }BTK+Tk8  
    O*;$))<wX  
        '************************************************************************* F8u;C:^d  
        'Lens thickness (Position of posterior lens surface) ['<Q402:.  
        '************************************************************************* up(6/-/.7  
    PxuE(n V[  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) h(M_ K  
    RKIBFP8.  
        ' Delete any z-shift(s) ORVFp]gG  
        count = 0 R,]J~TfPK  
        While GetOperationCount(eID)>count Y[_{tS#u  
            GetOperation eID, count, op <+7]EwVcn^  
            If op.Type="ShiftZ" Then T;7=05k<_  
                DeleteOperation eID,count DC9\Sp?  
                count=count-1 |p4D!M+$7  
            End If vy:-a G  
            count=count+1 JQi+y;  
        Wend ??\1eo2gB  
    ;Jh=7wx  
        'Set new z-shift *$%ch=  
        op.Type = "ShiftZ" xIOYwVC  
        op.val1 = tlens w'[^RZW:j  
        op.parent = parID 9'$\GN{0  
        AddOperation eID, op @u@ N&{b5"  
        Print "Set lens thickness = " & tlens tu4-##{  
    Ox| ?  
        '************************************************************************* SRU }-  
        'Lens index of refraction ID{62>R  
        '************************************************************************* P\jnht  
        eID = FindMaterial( "Lens" ) )Y@E5Tuk>  
        GetModelMaterial eID, mat D8OW|wVE  
    rI'kGqU  
        mat.Nd = nlens &ikPa,A  
        SetModelMaterial eID, mat xbVvK+  
        Print "Set lens index of refraction = " & nlens 9Dat oi  
    EgE% NY~  
        '************************************************************************* vkR,Sn  
        'Pupil diameter `, lnBP3D"  
        '************************************************************************* 5`_UIYcI  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) oouhP1py,  
    be<7Vy]j  
        'Adjust pupil diameter (trimming volume inner hole) g!QX#_~Il  
    [Re.sX}$Y  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" f9%M:cl  
    =c-Y >  
        ' Adjust pupil location to just in front of the lens +.czj,Sq  
        parID = FindFullName( "Geometry.Arizona Eye" ) j1 Ns|oph1  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) +hIC N,8!  
        count = 0 vtByCu5  
        While GetOperationCount(eID)>count 3rxB]-  
            GetOperation eID, count, op e(z'u A{!  
            If op.Type="ShiftZ" Then 8|cQW-L  
                DeleteOperation eID,count nB|m!fi<  
                count=count-1 T^Lg+g+I  
            End If r_"=DLx6  
            count=count+1 > w-fsL  
        Wend oCxh[U@*D  
        op.Type = "ShiftZ" <MQTOz oj  
        op.val1 = taq-0.01 >D\jyd$wh&  
        op.parent = parID .or1*-B K  
        AddOperation eID, op (kYwD  
    ["u:_2!4P  
        Print "Set pupil diameter = " & pupilDiam <rKfL`8p  
    r|ID]}w  
        'Update AZ Eye subassembly Description .UGbo.e  
        eID = FindFullName( "Geometry.Arizona Eye" ) ML!>tCT  
        GetEntity eID, entity af>^<q  
        entity.Description = "Accommodation = " & A & "D" lZ*V.-D^]  
        SetEntity eID, entity 2lu AF2  
    d71|(`&  
        Update x:? EL)(  
        Print "DONE!" 8[B0[2O  
         mS9ITe M  
    End Sub d#U~>wr  
    4!U)a  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: W#bOx0  
    _'}Mg7,V  
    Accommodation = 4 Diopters NI^jQS M]  
    Pupil Diameter = 4 mm oc>N| ww:  
    Set aqueous humor thickness = 2.81 6JB* brO  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 r.ib"W#4  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 '}, 8x?  
    Set lens thickness = 3.927 !+)5?o  
    Set lens index of refraction = 1.42672 @Rw]boC  
    Set pupil diameter = 4 /J5)_> R:  
    DONE! =JGL~t?  
     
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