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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 y4aSf2   
    j]EeL=H<P  
    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。 -LL49P6  
    } h|1H  
    模型 #C1u~db  
    8kQ >M  
    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。 YEoQIR  
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    Table 1. AZ眼睛模型的定义
    sQrP,:=r#  
    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. n?*Fr sZ  
    TI-8I)  
    光源 7/lXy3B4  
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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。 1u&}Lq(  
    -QL_a8NL  
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    图1. 光源和提示信息使用
    ^)Xl7d|m+  
    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。 / %}Xiqlrd  
    u1F@VV{  
    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。 Jrd:6Z  
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    图2. 字母F光源的设定方法光 <A +VS  
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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 RiC1lCE  
    :R+}[|FV  
    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。 p\66`\\l  
    V|3}~(5=  
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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。 hER]%)#r  
    F$P8"q+  
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    图5. 视网膜重点采样规格设定
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    脚本 X(Gp3lG  
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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: ?4Z`^uy  
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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
    [F4] pR(  
    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。 /1ZRjf^  
    余下的脚本计算与屈光度有关的所有参数。 L=4%MyZ.e  
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    分析 f0+)%gO{  
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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。 U:xY~>  
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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 {\3ZmF  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. \^O&){q(9  
    %fB]N  
    Dim entity As T_ENTITY {%W'Zx  
    Dim op As T_OPERATION rEEoR'c6  
    Dim mat As T_MODELMATERIAL <7-:flQz~  
    Dim A As Double IzPnbnS}  
    Dim pupilDiam As Double D?ojxHe  
    Dim eID As Long Fd!Np7xw  
    Dim parID As Long (/TYET_H  
    Dim count As Integer  [@YeQ{  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double M?mPi 3  
    Dim tlens As Double, nlens As Double / i[F  
    Dim curv As Double, conic As Double wWjZXsOd  
    Dim ok As Long [?z`XY_-  
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    Sub Main o9I=zAGjy  
    ~n9x ,  
        '用户输入对话框 a=n* }.  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,*_=w^;Rr  
            TextBox 220,21,40,21,.TextBox1 'default: 0 MYyV{W*T>  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 fS9TDy  
            OKButton 40,91,90,21 WUnz  
            CancelButton 190,91,90,21 >@?!-Fy5  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Fo\* Cr9D  
            TextBox 220,49,40,21,.TextBox2 'default: 4 VZhtx)  
        End Dialog H,8HGL[l  
        Dim dlg As UserDialog >Pa&f20Hp  
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        ok = Dialog (dlg) _{$eOwB  
    [_kis  
        If ok=0 Then    'cancel button was pressed hO8~Rg   
            Print "Execution cancelled." 'Lm\ r+$F  
            End O^/z7,  
        End If )wT @`p"4  
    g~ubivl2  
        'Assign accommodation and pupil diameter & use defaults if field left empty ;5S'?fj  
        If dlg.TextBox1 = "" Then :Y4 m3|  
            A = 0           'Default accommodation |.]sL0; 4Z  
        Else 2h=QJgpCG  
            A = CDbl(dlg.TextBox1) oUSv)G.zb  
        End If M/<>'%sj  
    ":igYh  
        If dlg.TextBox2 = "" Then ::<v; `l  
            pupilDiam = 4   'Default pupil diameter +"P!es\q  
        Else vca]yK<u  
            pupilDiam = CDbl(dlg.TextBox2)  ylTX  
        End If M%{,?a0V  
    _z6_mmMp  
        Print " " P]h-**O  
        Print "Accommodation = " & A & " Diopters" 8&q[jxI@8  
        Print "Pupil Diameter = " & pupilDiam & " mm" PCqE9B)l  
    RX])#=Cs  
        ' Calculate new parameters with accommodation 7 &O 0  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness *WzvPl$e  
    bX*>Zm   
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,M?K3lG\g[  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens n?a?U:  
    ;*+wg5|  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens %p; 'l  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens f3;.+hJ])  
    I9VU,8~  
        tlens = 3.767 + 0.04*A                  'Lens thickness q0sdL86  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction eN,6p '&  
    q$iGeE#  
        'Adjust parameters to account for accommodation H{1'OC  
    !pJd^|4A]  
        '************************************************************************* BmhIKXE{*  
        'Aqueous thickness (Position of Lens) GS)4,.  
        '************************************************************************* XbaUmCuh  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) fk5$z0/  
        GetCustomElement eID, entity Fo.p}j+>  
    ][?@) )  
        parID = FindFullName( "Geometry.Arizona Eye" ) (qyT,K8  
    oVAY}q|wU  
        ' Delete any shift(s) in z Oaj$Z- f  
        count = 0 3'jH,17lWV  
        While GetOperationCount(eID)>count OAiSE`  
            GetOperation eID, count, op v\ <4y P  
            If op.Type="ShiftZ" Then -hU1wX%U  
                DeleteOperation eID,count *S= c0  
                count=count-1 %=*nJvYS  
            End If wSPwa,)7s  
            count=count+1 Ljs4^vy <J  
        Wend ;N?raz2mEi  
    '_fj:dy  
        'Set new shift in .~AQxsGH  
        op.Type = "ShiftZ" Va-.  
        op.val1 = taq n4A#T#D!t3  
        op.parent = parID E``\Jre@  
        AddOperation eID, op '7yVvd  
        Print "Set aqueous humor thickness = " & taq-0.55 L (@".{T  
    vxZ :l  
        '************************************************************************* bNh~=[E  
        'Radius and conic constant of anterior lens ^&!iqK2o  
        '************************************************************************* /r?EY&9G  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) :8LK}TY7  
        GetConic eID, entity, curv, conic d>gN3}tT  
    c`s ]ciC  
        SetConic eID, entity, 1/Rant, CCant  %G>  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant "QLp%B,A  
    u5I#5  
        '************************************************************************* cM Z-  
        'Radius and conic constant of posterior lens ]yV,lp  
        '************************************************************************* m#|h22^H  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) DP6>fzsl  
        GetConic eID, entity, curv, conic @3_."-d  
    *wl&Zzx  
        SetConic eID, entity, 1/Rpost, CCpost $,8}3R5}  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost >k9W+mk  
    +@BjQ|UZ  
        '************************************************************************* ojbms>a  
        'Lens thickness (Position of posterior lens surface) q c DJ  
        '************************************************************************* E HH+)mlo  
    z;lWr(-x  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) XJ6=Hg4_O  
    VpyqVbx1  
        ' Delete any z-shift(s) 8T"8C  
        count = 0 XF i!=|F  
        While GetOperationCount(eID)>count jn._4TQ*}  
            GetOperation eID, count, op i:n1Di1~E  
            If op.Type="ShiftZ" Then Lt2<3DB  
                DeleteOperation eID,count c +N\uG4  
                count=count-1 8c<OX!  
            End If >p>B-m  
            count=count+1 a+ s%9l  
        Wend W.7XShwd*2  
    %ou@Y`  
        'Set new z-shift 4YyVh.x  
        op.Type = "ShiftZ" get$ r5  
        op.val1 = tlens O`TM}  
        op.parent = parID RCY}JH>}  
        AddOperation eID, op 19*D*dkBR  
        Print "Set lens thickness = " & tlens k~=W1R%  
    H:4? sR3  
        '************************************************************************* h: Hpz  
        'Lens index of refraction k*|WI$  
        '************************************************************************* >vZ^D  
        eID = FindMaterial( "Lens" ) r%FfJM@!  
        GetModelMaterial eID, mat ^+u/Lw&  
    G~{#%i  
        mat.Nd = nlens ; G4g;YHy|  
        SetModelMaterial eID, mat 1+9}Xnxb  
        Print "Set lens index of refraction = " & nlens i _YJq;(  
    w'&QNm>  
        '*************************************************************************  Fm`c  
        'Pupil diameter iu'At7  
        '************************************************************************* Lem:zXj  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) g;\_MbfP  
    [w?v !8l  
        'Adjust pupil diameter (trimming volume inner hole) R:, |xz  
    <4RP:2#  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" g n 6@x  
    0xzS9  
        ' Adjust pupil location to just in front of the lens ~vw$Rnotz  
        parID = FindFullName( "Geometry.Arizona Eye" ) L%31>)8  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) O=\`q6l  
        count = 0 9k3RC}dEr  
        While GetOperationCount(eID)>count v 0D@`C  
            GetOperation eID, count, op >L,Pw1Y0W[  
            If op.Type="ShiftZ" Then N6w!V]b  
                DeleteOperation eID,count I0v4TjHH  
                count=count-1 4N_iHe5U  
            End If de,4M s!%  
            count=count+1 N&]_U%#Q  
        Wend *5q_fO  
        op.Type = "ShiftZ" r%vO^8FQ  
        op.val1 = taq-0.01 x?n13C  
        op.parent = parID WNo<0|X  
        AddOperation eID, op L /V;;  
    Km!~zG7<  
        Print "Set pupil diameter = " & pupilDiam Y%#r&de  
    VZCCMh-  
        'Update AZ Eye subassembly Description P"<,@Mn  
        eID = FindFullName( "Geometry.Arizona Eye" ) YTV|]xpR  
        GetEntity eID, entity e8VtKVcY  
        entity.Description = "Accommodation = " & A & "D" A?ij  
        SetEntity eID, entity y/OPN<=*  
    /<)kI(gf  
        Update Bw4 _hlm  
        Print "DONE!" #GIjU1-  
         <iN xtD0  
    End Sub C#:L.qK  
    2M*84oh8P  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: y9X1X{  
    x|U[|i,;  
    Accommodation = 4 Diopters 1wt(pkNk  
    Pupil Diameter = 4 mm ]=jpqxlx  
    Set aqueous humor thickness = 2.81 &0JCZ /e  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 f/tJ>^N5  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 }D*5PV%d  
    Set lens thickness = 3.927 *Fm#Qek  
    Set lens index of refraction = 1.42672 eWU@ @$9  
    Set pupil diameter = 4 zi= gOm  
    DONE! ["SD'  
     
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