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    [技术]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: 2021-10-22
    简介 6"BtfQ")  
    Q2JdO 6[96  
    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。 |z.Gh1GCy  
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    模型 Dm7Y#)%8  
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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。 pem3G5 `g=  
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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. /X(@|tk:  
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    光源 :iP>z}h  
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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。 ^L>MZA ?  
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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。 FQ ;4'B^k]  
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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。 <_##YSGh,  
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    图2. 字母F光源的设定方法光 4M;sD;3  
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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 o0,UXBx  
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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。 &/b? I `  
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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。 'hwV   
    .Q=2WCv0  
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    图5. 视网膜重点采样规格设定
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    脚本 ?aK'OIo  
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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: an*]62l  
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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。 9f\aoVX  
    余下的脚本计算与屈光度有关的所有参数。 OqfhCNAY  
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    分析 J6@(X8w{j  
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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。 HGP%a1RF#  
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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 {pcf;1^t  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. d-6sC@PB  
    P?Gd}mdX?m  
    Dim entity As T_ENTITY ^%K1R;  
    Dim op As T_OPERATION +z]:CF  
    Dim mat As T_MODELMATERIAL lfU"SSQ  
    Dim A As Double d&PE,$XC  
    Dim pupilDiam As Double HMEs8.  
    Dim eID As Long F]K$u <U  
    Dim parID As Long hYP6z^  
    Dim count As Integer {#dp-5V  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Mr5('9%  
    Dim tlens As Double, nlens As Double rE1np^z7  
    Dim curv As Double, conic As Double "VT{1(]t  
    Dim ok As Long Z/V`Z* fy  
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    Sub Main kbIY%\QSO  
    *([0"  
        '用户输入对话框 \j2 : 6]Hm  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 }$&T O$LX  
            TextBox 220,21,40,21,.TextBox1 'default: 0 p"hm.=,  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 `@f hge  
            OKButton 40,91,90,21 bl:a&<F  
            CancelButton 190,91,90,21 |g7nh[  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 /I`cS%U  
            TextBox 220,49,40,21,.TextBox2 'default: 4 r)9i1rI+  
        End Dialog K,lK\^y  
        Dim dlg As UserDialog  m+72C]9  
    ~_dBND?  
        ok = Dialog (dlg) 8 7|8eU2:k  
    z{D$~ ob  
        If ok=0 Then    'cancel button was pressed i#@v_^q  
            Print "Execution cancelled." %9~kA5Qj  
            End F- !}dzO  
        End If BRo R"#'  
    DU*g~{8T$  
        'Assign accommodation and pupil diameter & use defaults if field left empty MYDf`0{$_a  
        If dlg.TextBox1 = "" Then WV,?Ge  
            A = 0           'Default accommodation |*]X\UE  
        Else ;*>QG6Fh  
            A = CDbl(dlg.TextBox1) _-|yCo  
        End If #whO2Mv  
    h|c:!VN@  
        If dlg.TextBox2 = "" Then +s+PnZ%0V  
            pupilDiam = 4   'Default pupil diameter np'M4^E;  
        Else LhVLsa(-%  
            pupilDiam = CDbl(dlg.TextBox2) ^huBqEs  
        End If q^jqLT&w  
    y:i[~y  
        Print " " eSvc/CU  
        Print "Accommodation = " & A & " Diopters" , IMT '*  
        Print "Pupil Diameter = " & pupilDiam & " mm" G(7\<x:  
    (zM+7tJH  
        ' Calculate new parameters with accommodation #RLch  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness NSiYUAu g  
     eo<~1w  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Ol/2%UJXL  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens N) V7yo?  
    2t]! {L  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens b]so9aCz  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens T_oW)G  
    -pU\"$nuxH  
        tlens = 3.767 + 0.04*A                  'Lens thickness }'w^<:RSy  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction fdCxMKlu;  
    e $/Zb`k  
        'Adjust parameters to account for accommodation 2\z`G  
    VvM U)  
        '************************************************************************* A\PV@w%A i  
        'Aqueous thickness (Position of Lens) vU \w3  
        '************************************************************************* ('o; M:  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) @|\s$L  
        GetCustomElement eID, entity x9&tlKKxf  
    9/X v&<Tn  
        parID = FindFullName( "Geometry.Arizona Eye" ) !g8.8(/t)  
    9%)& }KK|  
        ' Delete any shift(s) in z &' Nk2{  
        count = 0 ]uj.uWD  
        While GetOperationCount(eID)>count xt<, (4u  
            GetOperation eID, count, op g6a3MJV`  
            If op.Type="ShiftZ" Then 9V4V}[%  
                DeleteOperation eID,count a,0o{* (u$  
                count=count-1 7"CH\*%  
            End If ["#A-S  
            count=count+1 q2j}64o _S  
        Wend ss*2TE7  
    tpx3:|  
        'Set new shift in 4K?H-Jco  
        op.Type = "ShiftZ" g!kRa.`u1  
        op.val1 = taq 4iPua"8  
        op.parent = parID )S;Xy`vO  
        AddOperation eID, op G/RheH G  
        Print "Set aqueous humor thickness = " & taq-0.55 <2@<r t{  
    ?BWvF]p5/  
        '************************************************************************* o}^vREO  
        'Radius and conic constant of anterior lens W!Ct[t  
        '************************************************************************* C;:1CK  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~3-YxCn%  
        GetConic eID, entity, curv, conic aab4c^Ms=  
    Kp=3\)&  
        SetConic eID, entity, 1/Rant, CCant U-]PWt?C{  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant YDzF( ']o:  
    . =foXN  
        '************************************************************************* HI?~t| [y  
        'Radius and conic constant of posterior lens X)R] a]1A  
        '************************************************************************* PS<tS_.  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ]#7Y @Yo  
        GetConic eID, entity, curv, conic Mp @(/  
    vM3|Ti>a'  
        SetConic eID, entity, 1/Rpost, CCpost `zsk*W1GA  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3L!&~'.Ro  
    d<cbp [3F  
        '*************************************************************************  [;LPeO  
        'Lens thickness (Position of posterior lens surface) OFAqP1o{$  
        '************************************************************************* O>):^$-K%  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7Caap/L:  
    E~O>m8hF  
        ' Delete any z-shift(s) :)V0zHo&(  
        count = 0 %Ja{IWz9L  
        While GetOperationCount(eID)>count md +`#-D\O  
            GetOperation eID, count, op fF]&{b~wk  
            If op.Type="ShiftZ" Then m=l3O:~J  
                DeleteOperation eID,count /t6u"I~  
                count=count-1 X1z0'gvh  
            End If 9M~$W-5  
            count=count+1 Eq.zCD8A  
        Wend Pc ?G^ Xol  
    2uR4~XjF  
        'Set new z-shift nz?BLO=  
        op.Type = "ShiftZ" 4Jy,IKPp  
        op.val1 = tlens NeZYchR  
        op.parent = parID }~,cCtg:o  
        AddOperation eID, op $mg h.3z0  
        Print "Set lens thickness = " & tlens pO+wJ|f  
    a|{<#<6n(  
        '************************************************************************* eS%6 h U b  
        'Lens index of refraction (>lqp%G~  
        '************************************************************************* ZTz(NS EK  
        eID = FindMaterial( "Lens" ) *8eh%3_$h  
        GetModelMaterial eID, mat v&,VC~RN-J  
    mb6?$1j  
        mat.Nd = nlens =<uz'\Ytv%  
        SetModelMaterial eID, mat DmA!+  
        Print "Set lens index of refraction = " & nlens x=|@AFI  
    ZrT|~$*m`  
        '************************************************************************* xfQ;5n  
        'Pupil diameter \J g#X:d  
        '************************************************************************* Fm~}A4  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 5{f/H] P  
    Y$5v3E\uc  
        'Adjust pupil diameter (trimming volume inner hole) &`y_R'  
    ),FN29mZu  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 7Ki7N{K t  
    f5XcBW9E  
        ' Adjust pupil location to just in front of the lens JKv4}bv  
        parID = FindFullName( "Geometry.Arizona Eye" ) 7uH{UpslJ  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) %31K*i/]  
        count = 0 w|*G`~l09  
        While GetOperationCount(eID)>count TbM*?\7  
            GetOperation eID, count, op h0QQP  
            If op.Type="ShiftZ" Then zq>"a&Y,  
                DeleteOperation eID,count |L-juT X9  
                count=count-1 xH-k~#  
            End If 6>7LFV1tvy  
            count=count+1 -mdPqVIJn:  
        Wend j-E>*N}-_  
        op.Type = "ShiftZ" e%7P$.  
        op.val1 = taq-0.01 UsKn4Kh  
        op.parent = parID 5 : >  
        AddOperation eID, op *3oQS"8  
    wpMQ 7:j  
        Print "Set pupil diameter = " & pupilDiam DuZ]g#  
    E*"E{E7  
        'Update AZ Eye subassembly Description I=I%e3GEm  
        eID = FindFullName( "Geometry.Arizona Eye" ) "2j~3aWj  
        GetEntity eID, entity }eK*)  
        entity.Description = "Accommodation = " & A & "D" v xZUtyJfe  
        SetEntity eID, entity @TG~fJSA12  
    `G{t<7[[;  
        Update ^?`,f>`M  
        Print "DONE!" 'v)+S;oB  
         pDN,(Ip  
    End Sub 1#RA+d(  
    RtEkd_2  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ho<#i(  
    'm ((G4  
    Accommodation = 4 Diopters ;:1mv  
    Pupil Diameter = 4 mm cne[-E  
    Set aqueous humor thickness = 2.81 YR#1[fe*_  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ~qxc!k!w4  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 D4T+Gk"n  
    Set lens thickness = 3.927 AG=1TZI"  
    Set lens index of refraction = 1.42672 nJw1Sl5  
    Set pupil diameter = 4 _CT|5wQF<  
    DONE! -p~B -,  
     
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