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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 hgG9m[?K  
    qZdQD  
    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。 @?sRj&w  
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    模型 =jN.1}  
    .^`{1%  
    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。 T=DbBy0-  
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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. LE Nq_@$  
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    光源 zaIKdI'/e  
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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。 Wu/]MBM  
    5vQHhwO50k  
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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。 QT5TE: D  
    #lo6c;*m5  
    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。 =ZznFVJ`={  
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    图2. 字母F光源的设定方法光 :`#d:.@]o@  
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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 rgQOj^xKv^  
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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。 /U*C\ xMm  
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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。 VT)oLj/A  
    @gEUm_#HTs  
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    图5. 视网膜重点采样规格设定
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    脚本 %IA\pSE  
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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: 7aRi5  
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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。 gs[uD5oo<  
    余下的脚本计算与屈光度有关的所有参数。 7F7 {)L  
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    分析 {z5--TogJ  
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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。 2wg5#i  
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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 x+:UN'"r  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. IPKbMlV#d  
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    Dim entity As T_ENTITY ]cWUZ{puRB  
    Dim op As T_OPERATION VcYrK4  
    Dim mat As T_MODELMATERIAL d L 1tl  
    Dim A As Double u%KTNa0  
    Dim pupilDiam As Double Vb;*m5,?:  
    Dim eID As Long nNV'O(x}  
    Dim parID As Long (t K||*u  
    Dim count As Integer N)|yu1S  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~ 'cmSiz-  
    Dim tlens As Double, nlens As Double 7kLz[N6Ll  
    Dim curv As Double, conic As Double /{ l$sBUL  
    Dim ok As Long `2WFk8) F  
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    Sub Main ,eW%{[g(  
    #U4F0BdA  
        '用户输入对话框 a2O75 kWnm  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 BO ;tCEV?  
            TextBox 220,21,40,21,.TextBox1 'default: 0 4r#= *  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [Td4K.c  
            OKButton 40,91,90,21 #4% ]o%.  
            CancelButton 190,91,90,21 S~bOUdV Z  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 VBGuC c/  
            TextBox 220,49,40,21,.TextBox2 'default: 4 = `F(B  
        End Dialog ".V$~n(  
        Dim dlg As UserDialog (O?.)jEW(.  
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        ok = Dialog (dlg) Ecefi pG  
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        If ok=0 Then    'cancel button was pressed w~A{(- dx  
            Print "Execution cancelled." YeL#jtC  
            End Dlae;5 D  
        End If `Bp.RXsd*  
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        'Assign accommodation and pupil diameter & use defaults if field left empty e0zq1XcZ  
        If dlg.TextBox1 = "" Then $E~`\o%Ev  
            A = 0           'Default accommodation &*,#5.  
        Else )3}9K ^jS  
            A = CDbl(dlg.TextBox1) I\{ 1u  
        End If 7 :xfPx  
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        If dlg.TextBox2 = "" Then @7]yl&LZ  
            pupilDiam = 4   'Default pupil diameter u@UMP@"#  
        Else - t'jNR'  
            pupilDiam = CDbl(dlg.TextBox2) xb~yM%*c  
        End If 8@Q$'TT6}  
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        Print " " O!#g<`r{K  
        Print "Accommodation = " & A & " Diopters" @/.;Xw]  
        Print "Pupil Diameter = " & pupilDiam & " mm" T|eu  
     :D6 ON"6  
        ' Calculate new parameters with accommodation s}9S8@#  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness :Zbg9`d*  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens _[c0)2h  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 5|j<`()H :  
    ^R7lom.  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens fI}to&qk  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens v5#j Z$<F  
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        tlens = 3.767 + 0.04*A                  'Lens thickness *20jz<  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction v6bGjVK[  
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        'Adjust parameters to account for accommodation DS(}<HK{  
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        '************************************************************************* P|tO<t6/9*  
        'Aqueous thickness (Position of Lens) wx= $2N6  
        '************************************************************************* yy^q2P  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) qpP=K $  
        GetCustomElement eID, entity p Z|V 3  
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        parID = FindFullName( "Geometry.Arizona Eye" ) i(%W_d!  
    _?m(V=z>  
        ' Delete any shift(s) in z XH4  
        count = 0 J s@hLP `  
        While GetOperationCount(eID)>count UT~4x|b:O  
            GetOperation eID, count, op ;;OAQ`  
            If op.Type="ShiftZ" Then s 8jV(P(O  
                DeleteOperation eID,count A Ru2W1g  
                count=count-1 TCwFPlF|  
            End If GX!G>  
            count=count+1 a od-3"7[  
        Wend ~*&H$6NJS  
    -8ywO"6  
        'Set new shift in *eTqVG.  
        op.Type = "ShiftZ" EPI4!3]  
        op.val1 = taq /!yU !`bY  
        op.parent = parID ,GbR!j@6  
        AddOperation eID, op ,F8Yn5h  
        Print "Set aqueous humor thickness = " & taq-0.55 n`B:;2X,  
    H7&8\ FNa  
        '************************************************************************* 0y'H~(  
        'Radius and conic constant of anterior lens \R9(x]nZ%  
        '************************************************************************* Y1W1=Uc uk  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) .nf#c.DI  
        GetConic eID, entity, curv, conic 1Ti f{i,B  
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        SetConic eID, entity, 1/Rant, CCant  L2[($l  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 2+ N]PW\V  
    b5dD/-Vj  
        '************************************************************************* hP%M?MKC  
        'Radius and conic constant of posterior lens ?|\ER#z  
        '************************************************************************* W dK #ZOR  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Tj` ,Z5vy  
        GetConic eID, entity, curv, conic 5FPM`hLT  
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        SetConic eID, entity, 1/Rpost, CCpost x*\Y)9Vgy  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost +;(c:@>@,  
    `t>l:<@%  
        '************************************************************************* A7Cm5>Y_S  
        'Lens thickness (Position of posterior lens surface) <y('hI'  
        '************************************************************************* +6M}O[LP  
    "rALt~AX  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) '5#^i:  
    `!3SF|x&  
        ' Delete any z-shift(s) aB2F C$z  
        count = 0 W s3)gvpPA  
        While GetOperationCount(eID)>count 13$%,q)  
            GetOperation eID, count, op I;,77PxD  
            If op.Type="ShiftZ" Then [: n'k  
                DeleteOperation eID,count t9GR69v:?  
                count=count-1 v|_K/|  
            End If c)6m$5]  
            count=count+1 lne4-(DJ  
        Wend ,a{P4Bq  
    RtkEGxw*^  
        'Set new z-shift DD+7V@  
        op.Type = "ShiftZ" G/y5H;<9M  
        op.val1 = tlens P[G)sA_"  
        op.parent = parID "b~+;<}Q  
        AddOperation eID, op ^&9zw\x;z  
        Print "Set lens thickness = " & tlens #X+JHl  
    n$A9_cHF7  
        '************************************************************************* T#T*Zw"+  
        'Lens index of refraction Di,^%  
        '************************************************************************* GLH0 ]  
        eID = FindMaterial( "Lens" ) hIYNhZv  
        GetModelMaterial eID, mat y;m|  
    S1T"Z{$  
        mat.Nd = nlens K(e$esLs-  
        SetModelMaterial eID, mat 9d0@wq.  
        Print "Set lens index of refraction = " & nlens Si4!R+4w  
    9R!atPz9  
        '************************************************************************* gMi0FO'  
        'Pupil diameter $8)+XmsCr  
        '************************************************************************* F>SRs=_  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) { T/[cu<  
    d~])K#oJ  
        'Adjust pupil diameter (trimming volume inner hole) Fk&c=V;SU  
    r8t}TU>C  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" `z}?"BW|  
    +qN>.y!Y  
        ' Adjust pupil location to just in front of the lens '0;l]/i.  
        parID = FindFullName( "Geometry.Arizona Eye" ) /cUO$m o  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) aL\PGdgO  
        count = 0 &N$<e(K  
        While GetOperationCount(eID)>count lf`{zc r:  
            GetOperation eID, count, op MVpGWTH@F  
            If op.Type="ShiftZ" Then w0 M>[ 4  
                DeleteOperation eID,count ~Py`P'+  
                count=count-1 B6+khuG(  
            End If B B{$&Oh  
            count=count+1 L?b~k=  
        Wend ql Ax  
        op.Type = "ShiftZ" $j%'{)gK  
        op.val1 = taq-0.01 RXMISt3+{y  
        op.parent = parID tH@Erh|%  
        AddOperation eID, op ^cC,.Fdw  
    l K{hVqpt  
        Print "Set pupil diameter = " & pupilDiam etDk35!h~,  
    BiLY(1,  
        'Update AZ Eye subassembly Description +yG~T  
        eID = FindFullName( "Geometry.Arizona Eye" ) >a<.mU|#  
        GetEntity eID, entity 6D;Sgc5"  
        entity.Description = "Accommodation = " & A & "D" vQG5*pR*w  
        SetEntity eID, entity *}qWj_RT  
    0(}t8lc  
        Update e-/&$Qq  
        Print "DONE!" )th<,Lo3#  
         @}u*|P*  
    End Sub C\3rJy(VJ  
    T3.&R#1M8-  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: S&5&];Ag  
    HQ_Ok `  
    Accommodation = 4 Diopters aH(J,XY  
    Pupil Diameter = 4 mm h]&GLb&<?  
    Set aqueous humor thickness = 2.81 Ux!p8  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 a#(?P.6  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 UBU=9a5  
    Set lens thickness = 3.927 w>&aEv/f  
    Set lens index of refraction = 1.42672 HXC ;Np  
    Set pupil diameter = 4 |*eZD-f  
    DONE!  `,*3[  
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