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    [分享]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: 2020-12-09
    简介 'z[Sp~I\  
    o0pII )v  
    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。 ]GRWnif  
    3:C oZ  
    模型 d.P\fPSD  
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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。 c.j$9=XLBG  
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    Table 1. AZ眼睛模型的定义
    'CN|'W)g7  
    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. ;W^o@*i{>  
    Oj^,m.R  
    光源 D`VM6/iQR  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 |P%DkM*X  
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    图1. 光源和提示信息使用
    IzpZwx^3''  
    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 1+U  
    J52 o g4l  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 :at$HCaK  
    Ba/Yl  
    图2. 字母F光源的设定方法光 ~>+]%FPv  
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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 n2fbp\I  
    /\W Qx e  
    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。 2!$gyu6bpG  
    &Y^WP?HS  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 ;asP4R=  
    1)[]x9]^q'  
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    图5. 视网膜重点采样规格设定
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    脚本 57g</ p  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: :bC40@  
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    图6. 用户对话框的创建与编辑
    6A=8+R'`F  
    图7. 用户对话框编辑器
    |USX[j m\  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 HVC >9_:]  
    余下的脚本计算与屈光度有关的所有参数。 (1NA  
    44F`$.v96  
    分析 \R3H+W  
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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。 r{rQu-|.  
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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 3hK#'."`N  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. xu'yVt9RC  
    Vb'7>  
    Dim entity As T_ENTITY @-&s: Qli  
    Dim op As T_OPERATION Nq@+'<@p$  
    Dim mat As T_MODELMATERIAL ubmrlH\d  
    Dim A As Double L^{|uP15N  
    Dim pupilDiam As Double "&%#!2  
    Dim eID As Long VV9_`myN7  
    Dim parID As Long nM0[P6p  
    Dim count As Integer ?K3(D;5 &i  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double leQT-l2Bk  
    Dim tlens As Double, nlens As Double `3Uj{w/Q:L  
    Dim curv As Double, conic As Double wW%4d  
    Dim ok As Long U2%.S&wS,e  
    "1-}A(X  
    Sub Main "hdvHUz  
    p}<w#p |  
        '用户输入对话框 H~E(JLcU  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 MX ;J5(Ae  
            TextBox 220,21,40,21,.TextBox1 'default: 0 i}~SDY  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 0p@k({]<  
            OKButton 40,91,90,21 DzheoA-+L'  
            CancelButton 190,91,90,21 Q[d}J+l4{  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 5P'p2x#U  
            TextBox 220,49,40,21,.TextBox2 'default: 4 cDI [PJ9  
        End Dialog =2 *rA'im  
        Dim dlg As UserDialog =dx1/4bZl|  
    Zx d~c]n  
        ok = Dialog (dlg) po}F6m8bX  
    ZZyDG9a>7  
        If ok=0 Then    'cancel button was pressed D3x/OyG(  
            Print "Execution cancelled." YQS5P#  
            End %~QO8q_7  
        End If 7YAIA%8  
    s-S }i{Z!  
        'Assign accommodation and pupil diameter & use defaults if field left empty Rd>B0;4  
        If dlg.TextBox1 = "" Then yA3wtm/?  
            A = 0           'Default accommodation kMsnW}Nu  
        Else ~M(5Ho  
            A = CDbl(dlg.TextBox1) E!O\87[  
        End If yu;SH[{Wi  
    G\a8B#hg  
        If dlg.TextBox2 = "" Then 2mq$H_  
            pupilDiam = 4   'Default pupil diameter 7 K{Nb  
        Else 5IbJ  
            pupilDiam = CDbl(dlg.TextBox2) x+G0J8cW  
        End If _A0mxq  
    Z'k|u4ZC  
        Print " " (4%YHS8  
        Print "Accommodation = " & A & " Diopters" /o2P+Xr8"  
        Print "Pupil Diameter = " & pupilDiam & " mm" q}FVzahv  
    g%k`  
        ' Calculate new parameters with accommodation c1xrn4f@a  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness . ]8E7  
    0W%@gs5d&  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens u@3y&b  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens dCFlM&(i  
    $ F S_E  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens c   c  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens NOS>8sy  
    w%zRHf8C  
        tlens = 3.767 + 0.04*A                  'Lens thickness ]1gx#y 2  
    |G/7_+J6  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction efY8M2  
    9TAj) {U%'  
        'Adjust parameters to account for accommodation {W\T"7H  
    dgo3'ZO  
        '************************************************************************* DE IB!n   
        'Aqueous thickness (Position of Lens) d` Sr4c  
        '************************************************************************* j.:h5Y^N  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) J/6`oh?,Q  
        GetCustomElement eID, entity cc44R|Kr$$  
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        parID = FindFullName( "Geometry.Arizona Eye" ) TH&qX  
    k'X;ruQ:tF  
        ' Delete any shift(s) in z "3F;cCDv]  
        count = 0 pN&c(=If  
        While GetOperationCount(eID)>count  a1j.fA  
            GetOperation eID, count, op &Z^ l=YH,  
            If op.Type="ShiftZ" Then sFDG)  
                DeleteOperation eID,count bOI3^T  
                count=count-1 ;<Km 3  
            End If 5TUNX^AW  
            count=count+1 @d&/?^dp6  
        Wend RB?V7uX  
    %5\3Aw  
        'Set new shift in Yif*"oO  
        op.Type = "ShiftZ" \VSATL:]  
        op.val1 = taq ~l~Tk6EM  
        op.parent = parID mNYl@+:psj  
        AddOperation eID, op ai*b:Q  
        Print "Set aqueous humor thickness = " & taq-0.55 tU/k-W3X  
    i5F:r|  
        '************************************************************************* w-$[>R[hw  
        'Radius and conic constant of anterior lens G9g6.8*&  
        '************************************************************************* +([!A6:  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ,1/}^f6  
        GetConic eID, entity, curv, conic NcM>{{8  
    !Ss HAE|  
        SetConic eID, entity, 1/Rant, CCant :"o o>  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant l\$ +7|W  
    rbqo"g`  
        '************************************************************************* 4l8BQz}sb  
        'Radius and conic constant of posterior lens V,ZY*f0  
        '************************************************************************* _;RVe"tR#  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Pgp {$ID  
        GetConic eID, entity, curv, conic rp7W }P+uU  
    XUV!C 7  
        SetConic eID, entity, 1/Rpost, CCpost gBk5wk_j|  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost <f~Fl^^8  
    =22ALlxk  
        '************************************************************************* kJ)gP2E  
        'Lens thickness (Position of posterior lens surface) AAUyy :  
        '************************************************************************* zX7q:Pt  
    nkeI60  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) FnHi(S|A  
    C+N F9N  
        ' Delete any z-shift(s) vs&8wbS)  
        count = 0 kD.pzx EM  
        While GetOperationCount(eID)>count uM(UO,X  
            GetOperation eID, count, op %zo= K}u  
            If op.Type="ShiftZ" Then _2vd`k  
                DeleteOperation eID,count I]}>|  
                count=count-1 5 ZfP  
            End If qI3NkVA'C  
            count=count+1 p D=w >"  
        Wend z"F*\xa  
    #NRh\Wj|  
        'Set new z-shift ")lw9t`  
        op.Type = "ShiftZ" b*,3< 9  
        op.val1 = tlens }{],GHCjQ  
        op.parent = parID gY9\o#)<  
        AddOperation eID, op ~0-g%C?R  
        Print "Set lens thickness = " & tlens t"s5\;IJ  
    ] y1fM0  
        '************************************************************************* _`a&9i &  
        'Lens index of refraction XY+y}D %  
        '************************************************************************* 2>hz_o{5',  
        eID = FindMaterial( "Lens" ) (xyS7q]m  
        GetModelMaterial eID, mat keqcV23k  
    %c6E-4b  
        mat.Nd = nlens 0-2"FdeQU  
        SetModelMaterial eID, mat yFpySvj }  
        Print "Set lens index of refraction = " & nlens Yr&Ka:  
    @Z\~  
        '************************************************************************* mrZ`Lm#>pS  
        'Pupil diameter &$ p[  
        '************************************************************************* IjZ@U%g@;  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) z \?UGxu}  
    E20 :uZ7\  
        'Adjust pupil diameter (trimming volume inner hole) !0fI"3P@r  
    KAb(NZK  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ^b53}f8H  
    yBn_Kd  
        ' Adjust pupil location to just in front of the lens v:d9o.h  
        parID = FindFullName( "Geometry.Arizona Eye" ) T{S4|G1R6  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) m@ oUvxcd  
        count = 0 D[>W{g $  
        While GetOperationCount(eID)>count HcJE0-"  
            GetOperation eID, count, op k90B!kg  
            If op.Type="ShiftZ" Then W^xZ+]  
                DeleteOperation eID,count 9 qH[o?]  
                count=count-1  *W^=XbG  
            End If [b`6v`x  
            count=count+1 lfy7w|  
        Wend =s[ &;B`s  
        op.Type = "ShiftZ"  Tb#  
        op.val1 = taq-0.01 %D^bah f  
        op.parent = parID v.`+I-\.z)  
        AddOperation eID, op KU2$5[~j  
    yDtOpM8<{  
        Print "Set pupil diameter = " & pupilDiam F1}  
    o =9'  
        'Update AZ Eye subassembly Description QHQj/)J8  
        eID = FindFullName( "Geometry.Arizona Eye" ) r'd/qnd  
        GetEntity eID, entity aJ2H.E  
        entity.Description = "Accommodation = " & A & "D" /2h][zrZ[.  
        SetEntity eID, entity 5\G)Q<A]*L  
    %c1FwAC  
        Update !0dX@V'r  
        Print "DONE!" k!13=Gh  
         cV]y=q 6  
    End Sub NW De-<fQ  
    pbdF]>\  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ve%l({  
    ^/{4'\p  
    Accommodation = 4 Diopters 4e/cqN 6  
    Pupil Diameter = 4 mm 0P9Wy!f7  
    Set aqueous humor thickness = 2.81 <bX 1,}?  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 yqBa_XPV8  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 DR{] sG  
    Set lens thickness = 3.927 5&qY3@I7l  
    Set lens index of refraction = 1.42672 [|<EDR  
    Set pupil diameter = 4 )KE_t^$  
    DONE! b_ JWnh  
     h,hL?imD  
    2[BA( B  
    QQ:2987619807 (txt8q  
     
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