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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 <tTNtBb  
    Lb$Uba-_  
    人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 `GqF/?i  
    /TbJCZ  
    模型 iJ58RY  
    u*l>)_HD  
    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 '*Y mYU  
    &S.p%Qe"  
    Table 1. AZ眼睛模型的定义
    w#9.U7@.  
    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. >;G_o="X  
    wa[J\lW  
    光源 1Mq"f 7X8  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 u^C\aujg  
    L~+aD2 E {  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 2pHR$GZ2  
    5Qg*j/z?  
    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。 :Dr4?6hdr  
    ,%m~OB #  
    图2. 字母F光源的设定方法光 f(}&8~&  
    )+ G0m,n  
    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 aU +uPP  
    49/2E@G4.  
    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。 e+Mm!\ ;`  
    )e[q% %ks  
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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。 OvdBUcp[  
    :1'1 n  
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    图5. 视网膜重点采样规格设定
    Mf"(P.GIS  
    脚本 ;,/G*`81B  
    6UN{Vjr%`  
    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: jz'%(6#'gW  
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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。 HU +271A8  
    余下的脚本计算与屈光度有关的所有参数。 brE%/%! e  
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    分析 T?n[1%K  
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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。 bMqS:+  
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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  M+=q"#&  
    '+|uv7|+v  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^s8JW"H  
    |c]L]PU  
    Dim entity As T_ENTITY tr 8Q{  
    Dim op As T_OPERATION >Y3zO2Cr  
    Dim mat As T_MODELMATERIAL 1{xkAy0  
    Dim A As Double &@&^k$du8q  
    Dim pupilDiam As Double GO#eI]>/r  
    Dim eID As Long 8r.MODZG/  
    Dim parID As Long jN+2+P%OL  
    Dim count As Integer p{V(! v|  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double '~6l 6wi  
    Dim tlens As Double, nlens As Double fK4O N'[R:  
    Dim curv As Double, conic As Double Zg])uM]\2i  
    Dim ok As Long ' #r^W2  
    x6yO2Yo  
    Sub Main Fw#wVs)@:  
    e+MsFXnB8  
        '用户输入对话框 j~ qm5}  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ciPaCrV  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Im`R2_(]  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \y/0)NL\  
            OKButton 40,91,90,21 6`'KM/   
            CancelButton 190,91,90,21 /P{'nI  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 i;+<5_   
            TextBox 220,49,40,21,.TextBox2 'default: 4 4,6?sTuX  
        End Dialog oW/H8q<wY  
        Dim dlg As UserDialog 1UH_"Q03  
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        ok = Dialog (dlg) ,Hc,]TPC4  
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        If ok=0 Then    'cancel button was pressed SQ`ec95',  
            Print "Execution cancelled." C Yk"  
            End }Tk*?tYt  
        End If  YP}r15P  
    %t-}dC&  
        'Assign accommodation and pupil diameter & use defaults if field left empty "CT`]:GGK  
        If dlg.TextBox1 = "" Then Z5>}  
            A = 0           'Default accommodation 3D rW[\  
        Else y{qKb:~wv  
            A = CDbl(dlg.TextBox1) Z@>WUw@ F  
        End If FiNB$A  
    D|5Fo'O^AV  
        If dlg.TextBox2 = "" Then EG!):P  
            pupilDiam = 4   'Default pupil diameter cNuBWLG  
        Else ^d/,9L\U  
            pupilDiam = CDbl(dlg.TextBox2) }D#[yE,=\  
        End If K}Pi"Le@W  
    }KL( -Ui$  
        Print " " *&yt;|y  
        Print "Accommodation = " & A & " Diopters" /\uW[mt  
        Print "Pupil Diameter = " & pupilDiam & " mm" {&Sr<d5  
    WPNvZg9*c  
        ' Calculate new parameters with accommodation ^cYt4NHXn  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness )pt#Pu  
    +QFY. >KH  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens h|&qWv  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens bMF`KRP2  
    V}"w8i+D?  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens [kg*BaG:  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens p[gq^5WuC  
    N]@e7P'9F  
        tlens = 3.767 + 0.04*A                  'Lens thickness ig,v6lqhM  
    E@$HO_;&  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction  'x\{sv  
    0--0+?  
        'Adjust parameters to account for accommodation <q#/z&F!  
    AVv 8Hhd  
        '************************************************************************* l 7=WO#Pb  
        'Aqueous thickness (Position of Lens) FiJU *  
        '************************************************************************* f0lK ,U@P  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5l(Q#pSX  
        GetCustomElement eID, entity L%O( I  
    p^QB^HEV  
        parID = FindFullName( "Geometry.Arizona Eye" ) ZYX(Cf  
    `]:&h'  
        ' Delete any shift(s) in z v/lQ5R1  
        count = 0 -J=N  
        While GetOperationCount(eID)>count $3MYr5  
            GetOperation eID, count, op u9%)_Q!14  
            If op.Type="ShiftZ" Then VjVL/SO/  
                DeleteOperation eID,count |F#L{=B  
                count=count-1 q+-Bl  
            End If x?B8b-*  
            count=count+1 (t)a u  
        Wend DR6 OR B7  
    Tb6c]?'U  
        'Set new shift in #/ Qe7:l  
        op.Type = "ShiftZ" Mw+8p}E  
        op.val1 = taq ?]L:j  
        op.parent = parID Xz, sL  
        AddOperation eID, op T&`H )o  
        Print "Set aqueous humor thickness = " & taq-0.55 0Bpix|mq  
    B}y-zj; T  
        '************************************************************************* $w$4RQk3n  
        'Radius and conic constant of anterior lens ~?)ST?&  
        '************************************************************************* 5#U*vGVT  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) n7 S~n k  
        GetConic eID, entity, curv, conic " Q~-C|x  
    aGz <Yip  
        SetConic eID, entity, 1/Rant, CCant *Q8d &$ ^  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?0VLx,kp  
    M6b; DQ  
        '************************************************************************* }Myi0I<  
        'Radius and conic constant of posterior lens <2a7>\74E0  
        '************************************************************************* jreY'y:  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 'j+J?Y^  
        GetConic eID, entity, curv, conic tCdgtZm  
    {s=$.Kg  
        SetConic eID, entity, 1/Rpost, CCpost =K)au$BE|  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost E}$K&<J'-  
    85fBKpEe  
        '************************************************************************* `_;VD?")*l  
        'Lens thickness (Position of posterior lens surface) @:s|X  
        '************************************************************************* _YH)E^If  
    i }5 #n  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) |h,aV(Q  
    E30VKh |  
        ' Delete any z-shift(s) {]}}rx'|P  
        count = 0 !.'@3-w]  
        While GetOperationCount(eID)>count r$*p  
            GetOperation eID, count, op .hCOi<wB  
            If op.Type="ShiftZ" Then b:S#Sz$  
                DeleteOperation eID,count K6.*)7$#  
                count=count-1 l }?'U  
            End If 4V7{5:oa  
            count=count+1 '~E&^K5hr  
        Wend @,-xaZ[  
    Cp_YIcnEJ  
        'Set new z-shift (,E.1j]ji  
        op.Type = "ShiftZ" QMzBx*g(  
        op.val1 = tlens ^zv28Wq>  
        op.parent = parID r)dT,X[}F  
        AddOperation eID, op PF1m :Iz`d  
        Print "Set lens thickness = " & tlens EV@xUq!x .  
    : /9@p  
        '************************************************************************* nJYcC"f  
        'Lens index of refraction 1_7}B4  
        '************************************************************************* @Zs}8YhC  
        eID = FindMaterial( "Lens" ) 0j1I  
        GetModelMaterial eID, mat DiAPs_@  
    6M"]p  
        mat.Nd = nlens @>J4K#"  
        SetModelMaterial eID, mat :Q\b$=,:  
        Print "Set lens index of refraction = " & nlens w$7*za2  
    4b8!LzKS  
        '************************************************************************* n2R{$^JxO  
        'Pupil diameter Frt_X%  
        '************************************************************************* G Cx]VN3 &  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <BQ4x.[  
    8KD7t&H  
        'Adjust pupil diameter (trimming volume inner hole) O1@xF9<  
    iuq-M?1  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (i7]N[  
    R tn.cSd  
        ' Adjust pupil location to just in front of the lens MOyQ4<_  
        parID = FindFullName( "Geometry.Arizona Eye" ) Jjz:-Uqq2  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) K ^1bR(a  
        count = 0 <!&&Qd-d6H  
        While GetOperationCount(eID)>count z@cL<.0CE  
            GetOperation eID, count, op vcAs!ls+  
            If op.Type="ShiftZ" Then S@zsPzw  
                DeleteOperation eID,count fw_V'l#\  
                count=count-1 8 @!/%"Kt2  
            End If r9G<HKl  
            count=count+1 R{3f5**0  
        Wend |-I[{"6q$@  
        op.Type = "ShiftZ" l?B\TA^  
        op.val1 = taq-0.01 '1=t{Rw  
        op.parent = parID bzmT.!  
        AddOperation eID, op AFl]w'=  
    QdG_zK>|e  
        Print "Set pupil diameter = " & pupilDiam K!k,]90Ko  
    r9@W8](\  
        'Update AZ Eye subassembly Description }7vX4{Yn  
        eID = FindFullName( "Geometry.Arizona Eye" ) G;FY2;adK  
        GetEntity eID, entity #P- S.b  
        entity.Description = "Accommodation = " & A & "D" &&|*GAjJ  
        SetEntity eID, entity 0,nDyTS^  
    #OH-LWZh  
        Update xF5q=%n  
        Print "DONE!" c0u!V+V%  
         by& #g  
    End Sub \A _g  
    9>qR6k ?  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: T?)?"b\qz  
    BULX*eOt  
    Accommodation = 4 Diopters .wx; !9  
    Pupil Diameter = 4 mm JMw1qPJQ  
    Set aqueous humor thickness = 2.81 6Ez}A|i  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 N9Yc\?_NU_  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 y_38;8ex  
    Set lens thickness = 3.927 h{yqNl  
    Set lens index of refraction = 1.42672 8\`]T%h  
    Set pupil diameter = 4 $TL~SVHj;{  
    DONE! Nj qUUkc  
     
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