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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 H,3\0BKk  
    *a;@*  
    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。 'rp }G&m  
    }o4N<%/+  
    模型 Q_-_^J  
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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。 eV:9y  
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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. 6tHO!`}1  
    fZ04!R  
    光源 ryF7  
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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。 9EDfd NN  
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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。 ]D[DU]K  
    !tfb*@{;'  
    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。 0"2=n.##  
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    图2. 字母F光源的设定方法光 L^2FQti>  
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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 S}APQ  
    ]8q3>  
    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。 eSWL rryY  
    eP*lI<NQ1  
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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。 i1H\#;`$  
    ~\{^%~[48  
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    图5. 视网膜重点采样规格设定
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    脚本 hxCvk/7sT  
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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: pw7[y^[Qg  
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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。 O@p]KSfk  
    余下的脚本计算与屈光度有关的所有参数。 /|xra8?H[  
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    分析 D8 hr?:I9  
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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。 ^i:`ZfA#  
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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 K~@Mg1R  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. +$oF]OO  
    &f&z_WU  
    Dim entity As T_ENTITY p.LFVFPT  
    Dim op As T_OPERATION @|Rrf*J?%  
    Dim mat As T_MODELMATERIAL MEwo}=B  
    Dim A As Double #1>X58I^  
    Dim pupilDiam As Double m1Y >Nj[f  
    Dim eID As Long V}\~ugN)y  
    Dim parID As Long 8 Y5  
    Dim count As Integer ! u:Weoz  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double <=f}8a.R3  
    Dim tlens As Double, nlens As Double FJasS8  
    Dim curv As Double, conic As Double .A6(D$ O k  
    Dim ok As Long lo[.&GD  
    YW{C} NA  
    Sub Main hWX% 66  
    xQUu|gtL4  
        '用户输入对话框 tKpmm`2  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 s`0QA!G{-  
            TextBox 220,21,40,21,.TextBox1 'default: 0 kT;S4B  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 S#+h$UVh  
            OKButton 40,91,90,21 {GC?SaK  
            CancelButton 190,91,90,21 3YVi" k?2  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 2Lx3=k  
            TextBox 220,49,40,21,.TextBox2 'default: 4 :_O%/k1\@  
        End Dialog 'Fmvu   
        Dim dlg As UserDialog Yb E-6|cz  
    ^<e.]F25M  
        ok = Dialog (dlg) tg{H9tU;  
    Hla0 5N' 4  
        If ok=0 Then    'cancel button was pressed y\ a1iy  
            Print "Execution cancelled." xD6@Qk  
            End b#X^=n2  
        End If o LvZ   
    B>2tZZko  
        'Assign accommodation and pupil diameter & use defaults if field left empty Z?\2F%  
        If dlg.TextBox1 = "" Then '#k0a,<N  
            A = 0           'Default accommodation ONe# rKJ_  
        Else %"P,1&\^  
            A = CDbl(dlg.TextBox1) #FNcF>3>  
        End If ?]*^xL;x?  
    78/Zk}I]  
        If dlg.TextBox2 = "" Then uuQ(&  
            pupilDiam = 4   'Default pupil diameter ~J P=T  
        Else m@^1JlH  
            pupilDiam = CDbl(dlg.TextBox2) qTqwPWW*  
        End If L31HG H2l  
    ]wtb-PC  
        Print " " p>upA)W]  
        Print "Accommodation = " & A & " Diopters" 3? HhG  
        Print "Pupil Diameter = " & pupilDiam & " mm" Vv ?-"\Z>  
    <TP=oq?I/  
        ' Calculate new parameters with accommodation V>b\[(=s  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 5=Di<!a;  
    ~P@Q7T*  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Z /9>  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens u,UmrR  
    S;)w.  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens |>#{[wko  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ~/P&Tub^  
    |cR;{Z8?_  
        tlens = 3.767 + 0.04*A                  'Lens thickness F F|FU<  
    *m#Za<_Gv  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }nL7T'$>  
    8p:j&F  
        'Adjust parameters to account for accommodation @w?P7P<O`  
    PF53mUs4  
        '************************************************************************* .dav8n*  
        'Aqueous thickness (Position of Lens) Dp':oJC  
        '************************************************************************* R.yC(r  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 43@{JK9G  
        GetCustomElement eID, entity 2'W<h)m)z  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 7eiV{tYF  
    7D;cw\ |  
        ' Delete any shift(s) in z Gy6l<:;  
        count = 0 tfGHea)M  
        While GetOperationCount(eID)>count OEkN(wF  
            GetOperation eID, count, op @ g&ct>@y  
            If op.Type="ShiftZ" Then ;9c<K  
                DeleteOperation eID,count +>r/0b  
                count=count-1 +w+} b^4  
            End If  {PVWD7  
            count=count+1 m+Rv+_R  
        Wend LL3#5AA"k|  
    IkGfnXJ  
        'Set new shift in "\3B^ e,  
        op.Type = "ShiftZ" e8GEoD  
        op.val1 = taq 5.MGaU^Z$  
        op.parent = parID zc;|fHW~O  
        AddOperation eID, op )s%[T-uKi  
        Print "Set aqueous humor thickness = " & taq-0.55 TL}++e 7+  
    iT%} $Lu~  
        '************************************************************************* p{j.KI s7  
        'Radius and conic constant of anterior lens %'X[^W  
        '************************************************************************* PEc=\?  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) j'HZ\_  
        GetConic eID, entity, curv, conic -}KC=,]vh  
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        SetConic eID, entity, 1/Rant, CCant [rSR:V?"a  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant .p e(lP  
    `0Oh_8"  
        '************************************************************************* yge,8i)c  
        'Radius and conic constant of posterior lens !0vG|C ;'  
        '************************************************************************* *tK\R&4,4s  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) '2[albxSc  
        GetConic eID, entity, curv, conic A}3=561F?5  
    `1bv@yzq  
        SetConic eID, entity, 1/Rpost, CCpost Ndi9FD3im  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost !Ikt '5/  
    x3o ]U)^  
        '************************************************************************* ' <@3i[M  
        'Lens thickness (Position of posterior lens surface) /(.mp<s0  
        '************************************************************************* /assq+H  
    CD~z=vlK-  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) a-|*?{o  
    yrC7F` .  
        ' Delete any z-shift(s) gk0(ANx  
        count = 0 "HDcmIXg&  
        While GetOperationCount(eID)>count @Bf%s(Uj+  
            GetOperation eID, count, op v5QqS8u_C  
            If op.Type="ShiftZ" Then ?B}{GL2)  
                DeleteOperation eID,count q)^Jj ?W  
                count=count-1 PqiB\~o@Z  
            End If f7X6fr<  
            count=count+1 qa0 yg8,<  
        Wend Yd#/1!A7u  
    =9fajRFTt  
        'Set new z-shift JNJ=e,O,  
        op.Type = "ShiftZ" k[:bQ)H  
        op.val1 = tlens 6{^E{go  
        op.parent = parID *fn*h[pV&  
        AddOperation eID, op 9*{[buZX  
        Print "Set lens thickness = " & tlens 9 mmCp&~Z  
    X ><?F|#7T  
        '************************************************************************* rjp-Fw~1w  
        'Lens index of refraction d;>#Sxf  
        '************************************************************************* `CgaS#  
        eID = FindMaterial( "Lens" ) rU2%dkTa  
        GetModelMaterial eID, mat :[hgxJu+  
    {6_|/KE9_  
        mat.Nd = nlens NqDHCI  
        SetModelMaterial eID, mat ?C&z]f3(:  
        Print "Set lens index of refraction = " & nlens oaoU _V  
    'i4_`^:+  
        '************************************************************************* w[I E  
        'Pupil diameter S&b*rA02zp  
        '************************************************************************* #nK>Z[  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) %\H|B0  
    ](wvu(y\E  
        'Adjust pupil diameter (trimming volume inner hole) /p+>NZ"b  
    &iA?+kV  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |Y[wzDYV  
    Od5JG .]  
        ' Adjust pupil location to just in front of the lens =p=rg$?  
        parID = FindFullName( "Geometry.Arizona Eye" ) /qy-qUh3h  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) @EnuJe  
        count = 0 .7.b :Dn0  
        While GetOperationCount(eID)>count .MJofE;Jn  
            GetOperation eID, count, op -wSg2'b4E  
            If op.Type="ShiftZ" Then /iJ4{p   
                DeleteOperation eID,count /$'AjIg4:&  
                count=count-1 3P^sM1  
            End If oIb|*gX^  
            count=count+1 TTt#a6eJ  
        Wend 49dd5ddr  
        op.Type = "ShiftZ" pm_u  
        op.val1 = taq-0.01 Dm-zMCf}Q  
        op.parent = parID #>mr[   
        AddOperation eID, op Ct=- 4  
    79xx2  
        Print "Set pupil diameter = " & pupilDiam jkt_5+S  
    f'VX Y-  
        'Update AZ Eye subassembly Description f=mZu1(FZ  
        eID = FindFullName( "Geometry.Arizona Eye" ) I.94v #r  
        GetEntity eID, entity ]A<~XIu  
        entity.Description = "Accommodation = " & A & "D" 6T#+V37  
        SetEntity eID, entity )XzI #iQ  
    h9Y%{v  
        Update zN:K%AiGxe  
        Print "DONE!" P)MDPI+~  
         ZsOIH<}S  
    End Sub t<|NLk.  
    A3iFI9Iv  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: YtfVD7m  
    UmclTGn  
    Accommodation = 4 Diopters 4*cU<  
    Pupil Diameter = 4 mm @vrV*!  
    Set aqueous humor thickness = 2.81 P:aJ#  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 @qnD=mE  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 86mp=6@  
    Set lens thickness = 3.927 9)gC6 IiW  
    Set lens index of refraction = 1.42672 ,}))u0q+:  
    Set pupil diameter = 4 By9*1H2R  
    DONE! ^WNrGF  
    <RG|Dx[:=  
    26k LhFS  
    QQ:2987619807 pFHz"]  
     
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