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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 Q6eN+i2 ;  
    #>@<n3rq  
    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。 m**0rpA  
    T.J`S(oI  
    模型 Mp^^!AP9  
    tSI& "-   
    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。 _k6x=V;9g  
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    Table 1. AZ眼睛模型的定义
    FPvuzBJ  
    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. r >E\Cco  
    g'KzdG`O0  
    光源 Akv(} !g  
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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。 Q@7l"8#[t  
    qbEKp HnB  
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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。 ? 7/W>  
    t8t}7XD   
    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。 .4H_Zt[2  
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    图2. 字母F光源的设定方法光 hyJ ded&D  
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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 j?Cr31  
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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。 AGl|>f)  
    ;,<r|.6U  
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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。 @YEw^J~  
    "kcpA#uD|  
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    图5. 视网膜重点采样规格设定
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    脚本 f0/jwfL  
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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: >]:N?[Y_~}  
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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。 [B}1z  
    余下的脚本计算与屈光度有关的所有参数。 ;%BhhmR)[  
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    分析 K?5B>dv@A  
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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。 m Y$nI -P  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 ^;0~6uBEJr  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ` (7N^@  
    rF Ko E%  
    Dim entity As T_ENTITY (! xg$Kz@  
    Dim op As T_OPERATION [>b  '}4  
    Dim mat As T_MODELMATERIAL jf$JaY  
    Dim A As Double mgJShn8]  
    Dim pupilDiam As Double c+@d'yR  
    Dim eID As Long %MfGVx}nG  
    Dim parID As Long Aivu%}_|  
    Dim count As Integer cxtLy&C  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double *Te4U5F  
    Dim tlens As Double, nlens As Double 2(c<U6#C'l  
    Dim curv As Double, conic As Double a"`g"ZRx  
    Dim ok As Long =giM@MV  
    Y&?|k'7  
    Sub Main mr:kn0  
    8vz_~p9%j  
        '用户输入对话框 GOv9 2$e  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 w o-O_uZB  
            TextBox 220,21,40,21,.TextBox1 'default: 0 qWRNHUd  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ke3HK9P;  
            OKButton 40,91,90,21 PY^^^01P  
            CancelButton 190,91,90,21 844tXMtPB\  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 IUh5r(d 68  
            TextBox 220,49,40,21,.TextBox2 'default: 4 t] n(5!L(  
        End Dialog p{mxk)A  
        Dim dlg As UserDialog ^4u3Q  
     opUKrB  
        ok = Dialog (dlg) ;whFaQi 4  
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        If ok=0 Then    'cancel button was pressed pRQ fx^ On  
            Print "Execution cancelled." JVJ1Ay/be  
            End |@o]X?^  
        End If g5kYyE  
    MZUF! B  
        'Assign accommodation and pupil diameter & use defaults if field left empty d8Q_6(Ar|  
        If dlg.TextBox1 = "" Then ?=;e.qK=71  
            A = 0           'Default accommodation GibggOj2Q,  
        Else xG*lV|<7>  
            A = CDbl(dlg.TextBox1) W (=Wg|cr  
        End If 2a._?(k_y  
    -V;0_Nx7p  
        If dlg.TextBox2 = "" Then 5XSxQG@k^z  
            pupilDiam = 4   'Default pupil diameter W2r6jm!  
        Else GL;x:2XA  
            pupilDiam = CDbl(dlg.TextBox2) /%J&/2Wz  
        End If @e.OU(Bf  
    nZ`2Z7!  
        Print " " LyJTK1]#  
        Print "Accommodation = " & A & " Diopters" 2fj0 I  
        Print "Pupil Diameter = " & pupilDiam & " mm" #a7Amh\nT  
    Z]7;u>2  
        ' Calculate new parameters with accommodation lRF_ k  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness -!C Y,'3  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens [6,]9|~  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens :f?,]|]+-  
    1K? & J2  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens C0t+Q  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ? BHWzo!  
     qrkRD*a  
        tlens = 3.767 + 0.04*A                  'Lens thickness .yK\&q[<  
    zbIwH6  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction c{m ;"ZCFS  
    Z!]U&Ax`Z  
        'Adjust parameters to account for accommodation [x$eF~Kp  
    RAg|V:/M  
        '************************************************************************* [}9XHhY1O=  
        'Aqueous thickness (Position of Lens) hSx+ {4PZ  
        '************************************************************************* 9z| >roNe  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {0A[v}X ~  
        GetCustomElement eID, entity D_yY0rRM  
    /+<%,c$n  
        parID = FindFullName( "Geometry.Arizona Eye" ) 5,0 wj0l  
    K+h9bI/Sf  
        ' Delete any shift(s) in z 7kX7\[zN  
        count = 0 Zv1Bju*y  
        While GetOperationCount(eID)>count Kbz7  
            GetOperation eID, count, op  z~}StCH(  
            If op.Type="ShiftZ" Then | z(Ws  
                DeleteOperation eID,count aCUV[CPw  
                count=count-1 GqIvvnw@f  
            End If _M"$5 T  
            count=count+1 {x&jh|f`g  
        Wend 282+1X  
    +]S;U&vQ  
        'Set new shift in -h G 9  
        op.Type = "ShiftZ" HjUw[Yz+6  
        op.val1 = taq m mJ)m  
        op.parent = parID S0Bl?XsD_  
        AddOperation eID, op w371.84  
        Print "Set aqueous humor thickness = " & taq-0.55 < o'7{  
    pzt Zb  
        '************************************************************************* e&H<lT  
        'Radius and conic constant of anterior lens -;@5Ua1uf  
        '************************************************************************* YzhN|!;!k  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) W3o }.|]  
        GetConic eID, entity, curv, conic xPfnyAo?%z  
    l9ifUh e  
        SetConic eID, entity, 1/Rant, CCant n6%jhv9H  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant *(\;}JF-  
    . ~A"Wyu\  
        '************************************************************************* *nsnX/e(-  
        'Radius and conic constant of posterior lens c>U{,z  
        '************************************************************************* ek{PA!9Sk  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) %8} ksl07  
        GetConic eID, entity, curv, conic LG&Q>pt.  
    $ vw}p.  
        SetConic eID, entity, 1/Rpost, CCpost XJxs4a1[t  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /_k hFw  
    /[0 /8f6  
        '************************************************************************* }d~FTre  
        'Lens thickness (Position of posterior lens surface) L yA(.  
        '************************************************************************* Za:BJ:  
    }%>$}4 ,  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" )  +s R *d  
    >nIcF m  
        ' Delete any z-shift(s) 8v)~J}[Bz  
        count = 0 @Pb 1QLiz  
        While GetOperationCount(eID)>count mk`cyN>m  
            GetOperation eID, count, op SG|i/K|7  
            If op.Type="ShiftZ" Then (y+5d00  
                DeleteOperation eID,count kkE)zF   
                count=count-1 2$i 0yPv  
            End If eVCkPv *  
            count=count+1 : 7DVc&0  
        Wend h$ETH1Ue  
    PM@s}(  
        'Set new z-shift _@~kYz  
        op.Type = "ShiftZ" #g`cih=QL  
        op.val1 = tlens PcSoG\- G<  
        op.parent = parID qiKtR  
        AddOperation eID, op ik:)-GV;s  
        Print "Set lens thickness = " & tlens Q!+{MsZ  
    g*AD$":  
        '************************************************************************* kJ<Xq   
        'Lens index of refraction %}]4Nsde  
        '************************************************************************* 8apKp?~yW  
        eID = FindMaterial( "Lens" ) U9p.Dh~)vG  
        GetModelMaterial eID, mat 1-]x  
    = a.n`3`Q  
        mat.Nd = nlens fddbXs0Sn  
        SetModelMaterial eID, mat UVBw;V  
        Print "Set lens index of refraction = " & nlens a9EI7pnq  
    dG~B3xg;5i  
        '************************************************************************* |e-+xX|;  
        'Pupil diameter wyzBkRg.  
        '************************************************************************* !q6V @&  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) X @jYQ.  
    < ,cIc]eX  
        'Adjust pupil diameter (trimming volume inner hole) +uiH0iGS  
    ]Y: W[p  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" h,6S$,UI  
    }Ka.bZS  
        ' Adjust pupil location to just in front of the lens x< y[na  
        parID = FindFullName( "Geometry.Arizona Eye" ) /2\= sTd  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) KjfKo;T  
        count = 0 w4MMo  
        While GetOperationCount(eID)>count 0)Xue9AS  
            GetOperation eID, count, op OTHd1PSOu  
            If op.Type="ShiftZ" Then FZ.z'3I  
                DeleteOperation eID,count Pc; 14M  
                count=count-1 ;7`um  
            End If ]-Y]Q%A4  
            count=count+1 {_X1&&>8/  
        Wend rB&j"p}Q  
        op.Type = "ShiftZ" RJs G]`  
        op.val1 = taq-0.01 eKFc W5O  
        op.parent = parID :2Rci`lp  
        AddOperation eID, op ?O>JtEz~lQ  
    .L{+O6*c  
        Print "Set pupil diameter = " & pupilDiam yY-t4WeXP  
    @NwM+^  
        'Update AZ Eye subassembly Description 2l/5i]Tq  
        eID = FindFullName( "Geometry.Arizona Eye" ) Yl~?MOk  
        GetEntity eID, entity -[7,ph  
        entity.Description = "Accommodation = " & A & "D" -5_xI)i  
        SetEntity eID, entity TN@JPoH  
    oS|~\,p"  
        Update M j%|'dZz  
        Print "DONE!" H{Y=&#%d  
         #\ S$$gP  
    End Sub -L50kk>h  
    #~-&&S4a.J  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: Wu;|(2I  
    j{-7Pf8A  
    Accommodation = 4 Diopters )Gp\_(9fc  
    Pupil Diameter = 4 mm M "P  
    Set aqueous humor thickness = 2.81 oUKbzr/C  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 'CAukk|  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 rxI&;F#  
    Set lens thickness = 3.927 Y^m=_*1g5  
    Set lens index of refraction = 1.42672 gsm^{jB  
    Set pupil diameter = 4 B|$13dHfa  
    DONE! R$&&kmJ  
     
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