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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 a;jXMR  
     I0trHrX9  
    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。 $@<qaR{t\  
    }J"}5O2,b  
    模型 X YO09#>&  
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    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 Mn7nS:  
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    Table 1. AZ眼睛模型的定义
    !*_5 B'  
    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. .]}kOw:(#  
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    光源 {h5 S=b  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 !_P;4E  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 WX$mAQDV  
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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。 WlVp|s{TYP  
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    图2. 字母F光源的设定方法光 (jv!q@@2C.  
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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 !mLQdkTE  
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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。 9N5ptdP.d  
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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。 `\LhEnIwu  
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    图5. 视网膜重点采样规格设定
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    脚本 v3SH+Ej4  
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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: /Ud<4j-  
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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。 mNS7/I\  
    余下的脚本计算与屈光度有关的所有参数。 Y Y4"r\V  
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    分析 _q*4+x  
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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。 rF C6"_  
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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 "J:~Aa%_  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. H{Tt>k  
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    Dim entity As T_ENTITY V?"X0>]0  
    Dim op As T_OPERATION g}HB|$P7  
    Dim mat As T_MODELMATERIAL oL?(; `"&  
    Dim A As Double tj:3R$a  
    Dim pupilDiam As Double "[(&$ I  
    Dim eID As Long xszGao'  
    Dim parID As Long 7d&_5Tj:  
    Dim count As Integer wcGI2aflD  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double jSa9UD  
    Dim tlens As Double, nlens As Double Cw`8[)=}o  
    Dim curv As Double, conic As Double 3k)W0]:|<  
    Dim ok As Long sjh>i>t  
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    Sub Main -<rQOPH%  
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        '用户输入对话框 VA4>!t)  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 m# #( uSh  
            TextBox 220,21,40,21,.TextBox1 'default: 0 x:'M\c7  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 cI}qMc  
            OKButton 40,91,90,21 `m2e *  
            CancelButton 190,91,90,21 .XPcH(q  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 m\a_0!K  
            TextBox 220,49,40,21,.TextBox2 'default: 4 1,cd[^`.  
        End Dialog %ux%=@%  
        Dim dlg As UserDialog !e~Yp0gX#  
    ~"\qX+  
        ok = Dialog (dlg) ?v-Y1j  
    d D6I @N)X  
        If ok=0 Then    'cancel button was pressed G dZ_  
            Print "Execution cancelled." z{h#l!Edh  
            End 4o,%}bo&  
        End If +$]eA'Bh@  
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        'Assign accommodation and pupil diameter & use defaults if field left empty a*4"j2j v  
        If dlg.TextBox1 = "" Then qyXx`'e  
            A = 0           'Default accommodation t;BvKH77  
        Else q^{Z"ifL  
            A = CDbl(dlg.TextBox1) ?f1PQ  
        End If |ocIp/ $  
    +<p?i]3CHe  
        If dlg.TextBox2 = "" Then \BB(0Ah+t  
            pupilDiam = 4   'Default pupil diameter ,:yv T6)p  
        Else :uM2cc^  
            pupilDiam = CDbl(dlg.TextBox2) eIVCg-l}  
        End If ) V}q7\G~  
    NOOP_:(7H  
        Print " " /Mq]WXq[V  
        Print "Accommodation = " & A & " Diopters" *We.?"X'].  
        Print "Pupil Diameter = " & pupilDiam & " mm" 3/ sKRU  
    npcB+6  
        ' Calculate new parameters with accommodation p #vZYwe=L  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness a`}b'X:  
    m5K B#\  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens i!zh9,i>M  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \EH:FM}l,  
    d~L`*"/)[  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens c*nH=  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ?h`Ned0P  
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        tlens = 3.767 + 0.04*A                  'Lens thickness gI^);J rTE  
    /m,0H)w1  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^{<x*/nK  
    AF{k^^|H  
        'Adjust parameters to account for accommodation _Q<wb8+/  
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        '************************************************************************* 7?6?`no~JJ  
        'Aqueous thickness (Position of Lens) ]h (TZu  
        '************************************************************************* ^+Ez[S{8  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) /'|'3J]HP  
        GetCustomElement eID, entity jF}zv  
    j7;v'eA`;7  
        parID = FindFullName( "Geometry.Arizona Eye" ) |_l\.  
    GD1=Fb"&)  
        ' Delete any shift(s) in z 6T6 S9A*nT  
        count = 0 AYHfe#!  
        While GetOperationCount(eID)>count i<D}"h|  
            GetOperation eID, count, op QZufQRfr{  
            If op.Type="ShiftZ" Then Uo{h. .7?  
                DeleteOperation eID,count yjvH)t/!.  
                count=count-1 l ' ]d&  
            End If 9GnNL I{  
            count=count+1 l*[.  
        Wend b6D}GuW  
    =J.)xDx*  
        'Set new shift in OwIW;8Z  
        op.Type = "ShiftZ" %UJ!(_  
        op.val1 = taq G'XlsyaWrb  
        op.parent = parID W5-p0,?[6  
        AddOperation eID, op 3j.Ft*SV  
        Print "Set aqueous humor thickness = " & taq-0.55 ~CRr)(M  
    bAeN>~WvY  
        '************************************************************************* 8F0+\40  
        'Radius and conic constant of anterior lens qF6YH  
        '************************************************************************* :W5*fE(i  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) yWIM,2x}  
        GetConic eID, entity, curv, conic $Aww5G5e  
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        SetConic eID, entity, 1/Rant, CCant GY4 :9Lub7  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant puS'9Lpp  
    <\x/Y$jm0n  
        '************************************************************************* ToJV.AdfT  
        'Radius and conic constant of posterior lens L>{E8qv>w  
        '************************************************************************* JJ56d)37.  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) BQf}S +  
        GetConic eID, entity, curv, conic Kp"mV=RG2T  
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        SetConic eID, entity, 1/Rpost, CCpost ~\hA-l36  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost N s9cx  
    VL"ZC:n)-  
        '************************************************************************* !m pRLBH  
        'Lens thickness (Position of posterior lens surface) wP1dPl_j:0  
        '************************************************************************* 9QJ=?bIC#  
    %iIryv;  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) </<_e0  
    1W-t})!a  
        ' Delete any z-shift(s) D0PP   
        count = 0 ) 0$7{3  
        While GetOperationCount(eID)>count AW6]S*rh  
            GetOperation eID, count, op ^BjwPh4Z#  
            If op.Type="ShiftZ" Then fl~k')s  
                DeleteOperation eID,count 6+IOJtj  
                count=count-1 !.L%kw7z  
            End If +IVVsVp  
            count=count+1 /exV6D r  
        Wend ;: Hfkyy]  
    8_f0P8R!y  
        'Set new z-shift -w 2!k  
        op.Type = "ShiftZ" RrLQM!~  
        op.val1 = tlens :RHNV  
        op.parent = parID .eXIbd<C  
        AddOperation eID, op HeGGAjc  
        Print "Set lens thickness = " & tlens L3nHvKA]  
    8,Yc1  
        '************************************************************************* !`,6E`Y#  
        'Lens index of refraction UuT>qWxQ8  
        '************************************************************************* dT,X8 "  
        eID = FindMaterial( "Lens" ) JU<<,0  
        GetModelMaterial eID, mat ?C.C?h6F5B  
    {exF" ap  
        mat.Nd = nlens P%pB]d.qpi  
        SetModelMaterial eID, mat  'm}~  
        Print "Set lens index of refraction = " & nlens #x#.@  
    D8h ?s  
        '************************************************************************* 3w {4G<I  
        'Pupil diameter 8c+i+gp!  
        '************************************************************************* S3hJL:3c  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  2b1LC!'U  
    ;^}cZ  
        'Adjust pupil diameter (trimming volume inner hole) o'myo.k{  
    {FQ dDIj#  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 3`#sXt9C  
    !i_5Xc H  
        ' Adjust pupil location to just in front of the lens 4OCz:t  
        parID = FindFullName( "Geometry.Arizona Eye" ) Ca+d ?IS  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 6$SsdT|8B  
        count = 0 z2!NBOv  
        While GetOperationCount(eID)>count &#.XLe\y  
            GetOperation eID, count, op w \0=L=J  
            If op.Type="ShiftZ" Then nImRU.;P  
                DeleteOperation eID,count Fxv~;o#  
                count=count-1 k6[t$|lMy  
            End If :+]6SC0ql  
            count=count+1 rVQ:7\=Z  
        Wend {+ [rJ_  
        op.Type = "ShiftZ" `{F8#    
        op.val1 = taq-0.01 a+\ Gz  
        op.parent = parID M%&`&{  
        AddOperation eID, op "793R^Tz  
    76=uk!#3{  
        Print "Set pupil diameter = " & pupilDiam 'y-IE#!5  
    xZ`t~4qR  
        'Update AZ Eye subassembly Description 'r1&zw(  
        eID = FindFullName( "Geometry.Arizona Eye" ) Vl^jTX5N  
        GetEntity eID, entity 8Mws?]\/q  
        entity.Description = "Accommodation = " & A & "D" %PlPXoG=  
        SetEntity eID, entity .RJvu$U2j  
    Yz-b~D/=}  
        Update ?/#HTg)!B  
        Print "DONE!" q#sMew\{  
         Gjy'30IF  
    End Sub \iowAo$  
    5Odi\SJ&  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ^Po\:x%o  
    s%4)}w;z  
    Accommodation = 4 Diopters s)/i_Oe$\  
    Pupil Diameter = 4 mm ,iSs2&$ m  
    Set aqueous humor thickness = 2.81 \,p)  
    Set anterior lens radius = 10.4 and conic constant = -2.375869  Kn\Oj=4  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 rQisk8 %  
    Set lens thickness = 3.927  PJk Mn  
    Set lens index of refraction = 1.42672  J|6aa  
    Set pupil diameter = 4 A.WJ#1i}E  
    DONE! 9Eg'=YJ  
     
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