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    [转载]FRED运用: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: 2016-02-24
    简介 t'BLVCu  
    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。 A$#p%y b  
    h.-@ F  
    模型 a["2VY6Eq@  
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    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 SV:4GVf  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 'rMN=1:iu"  
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    光源 )t$,e2FY  
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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。 B*4}GPQ  
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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。 XK|R8rhg8`  
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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。 0$7s^?G0  
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    图2. 字母F光源的设定方法光 X5X?&* %{  
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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 #<e\QE'!  
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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。 L3 G \  
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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。 QmLF[\Oo_  
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    图5. 视网膜重点采样规格设定
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    脚本 S,<EEtXQ  
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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: vC1v"L;[o/  
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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。 5B&;uY  
    余下的脚本计算与屈光度有关的所有参数。 0 ;b[QRmy  
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    分析 oP!;\a( SL  
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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。 AC;V m: @{  
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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 NPd%M  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. qTAc[Ko  
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    Dim entity As T_ENTITY dn }`i  
    Dim op As T_OPERATION ?Y:8eD"*  
    Dim mat As T_MODELMATERIAL %I-+Ead0i  
    Dim A As Double ;x:rZV/  
    Dim pupilDiam As Double LJOr!rWi  
    Dim eID As Long (y?I Tz9  
    Dim parID As Long p=C%Hmd5E  
    Dim count As Integer H"C[&r  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double srYJp^sC  
    Dim tlens As Double, nlens As Double mwY IJy[  
    Dim curv As Double, conic As Double $&<uT  
    Dim ok As Long ithewup  
    g8w2Vz2/  
    Sub Main "=6v&G]U4  
    [74F6Qp  
        '用户输入对话框  qNm$Fx  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2*N_5&9mE  
            TextBox 220,21,40,21,.TextBox1 'default: 0 /Nr*`l  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Pt&(npjN,  
            OKButton 40,91,90,21 AgRjr"hF*e  
            CancelButton 190,91,90,21 ,_X /Gb6)  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ^-rfvc  
            TextBox 220,49,40,21,.TextBox2 'default: 4 \MK*by  
        End Dialog F:D orE  
        Dim dlg As UserDialog #fJ] o_  
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        ok = Dialog (dlg) e]T`ot#/  
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        If ok=0 Then    'cancel button was pressed f{"8g"[[)(  
            Print "Execution cancelled." 7C$ 5  
            End G NS`.fS  
        End If ?[& 2o|  
    = <j"M85.  
        'Assign accommodation and pupil diameter & use defaults if field left empty ;U<rc'qE  
        If dlg.TextBox1 = "" Then {0;3W7  
            A = 0           'Default accommodation *dvDap|8W  
        Else w|CZ7|6  
            A = CDbl(dlg.TextBox1) Qc[3Fq,f  
        End If N<Q jdD&  
    H*bs31i{  
        If dlg.TextBox2 = "" Then ?%VI{[y#>  
            pupilDiam = 4   'Default pupil diameter M;0]u.D*=  
        Else @x eAc0.^  
            pupilDiam = CDbl(dlg.TextBox2)  Y!WG)u5  
        End If Fbu5PWhlc  
    PG8^.)]M  
        Print " " ?-tVSRKQ  
        Print "Accommodation = " & A & " Diopters" MwfOy@|N  
        Print "Pupil Diameter = " & pupilDiam & " mm" >7roe []-|  
    Ja SI^go  
        ' Calculate new parameters with accommodation .<z!3O&L  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness =l.+,|ZH!  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 1Nu1BLPm  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens xil[#W]7Ge  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens .TE?KI   
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens RZe'Kw -  
    -QyhwG =  
        tlens = 3.767 + 0.04*A                  'Lens thickness gr-fXZO  
    sz @p_Z/  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction MWNPPYww  
    ,+g&o^T  
        'Adjust parameters to account for accommodation \}~s2Y5j  
    wBQF~WY  
        '************************************************************************* &QG6!`fK}3  
        'Aqueous thickness (Position of Lens) i5>+}$1  
        '************************************************************************* +525{Tj  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) y7S4d~&  
        GetCustomElement eID, entity .XkMk|t8  
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        parID = FindFullName( "Geometry.Arizona Eye" ) k<RZKwQc  
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        ' Delete any shift(s) in z 66#"  
        count = 0 \m=?xb8 f  
        While GetOperationCount(eID)>count En&5)c+js4  
            GetOperation eID, count, op zZiJ 9 e  
            If op.Type="ShiftZ" Then &20P,8@  
                DeleteOperation eID,count cEe? *\G  
                count=count-1 *jMk/9oa<N  
            End If XE3'`D !  
            count=count+1 ^ FZ^6*  
        Wend >a1{397Y}  
    =<@\,xN>C  
        'Set new shift in W5/0`[4  
        op.Type = "ShiftZ" m^_6:Q0F!8  
        op.val1 = taq ubu?S%`  
        op.parent = parID 'a^{=+  
        AddOperation eID, op G pbC M~x  
        Print "Set aqueous humor thickness = " & taq-0.55 BZb]SoAL  
    83cW=?UgA  
        '************************************************************************* "xAWG$b  
        'Radius and conic constant of anterior lens CSV;+,Vv  
        '************************************************************************* 577:u<Yt  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) X%bFN  
        GetConic eID, entity, curv, conic hI pKJ&hm  
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        SetConic eID, entity, 1/Rant, CCant okq[ o90  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 51# "3S  
    M=xQ=j?  
        '************************************************************************* xsjO)))f  
        'Radius and conic constant of posterior lens XJ!(F#zc  
        '*************************************************************************  q{die[J  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) IMnP[WA!  
        GetConic eID, entity, curv, conic /D_+{dtE  
    .$", *d  
        SetConic eID, entity, 1/Rpost, CCpost $KjTa#[RX7  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost -ng=l;  
    Q,Z*8FH=  
        '************************************************************************* Px M!U!t  
        'Lens thickness (Position of posterior lens surface) M}DH5H"s  
        '************************************************************************* ha;l(U>  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) vRA',(](  
    BpO9As 1um  
        ' Delete any z-shift(s) 69kJC/1+l  
        count = 0 <B /5J:o<  
        While GetOperationCount(eID)>count ,jy*1Hjd  
            GetOperation eID, count, op Ip}Vb6}  
            If op.Type="ShiftZ" Then kW6%32  
                DeleteOperation eID,count Sx ] T/xq  
                count=count-1 Lc<eRVNd,  
            End If E?PGu!&u  
            count=count+1 kqvow3u  
        Wend 6Ggs JU  
    ZX b}91rzt  
        'Set new z-shift W v!<bT8r  
        op.Type = "ShiftZ" 3Dm8[o$Z  
        op.val1 = tlens DhI>p0* T  
        op.parent = parID g"Q h]:  
        AddOperation eID, op pz_e=xr  
        Print "Set lens thickness = " & tlens 1xnLB>jP#  
    v| z08\a[  
        '************************************************************************* SC#sax4N!=  
        'Lens index of refraction (}!C4S3#  
        '************************************************************************* 2aNT#J"_  
        eID = FindMaterial( "Lens" ) 7Tf]:4Y"  
        GetModelMaterial eID, mat # Oup^ o@  
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        mat.Nd = nlens Mo|wME#M  
        SetModelMaterial eID, mat TUp%FJXA|  
        Print "Set lens index of refraction = " & nlens Cd#E"dY6  
    qH%")7>  
        '************************************************************************* 7N2\8kP  
        'Pupil diameter w#G2-?aj  
        '************************************************************************* 9x~-*8aw  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) j?(!^ _!m  
    6k])KlJ2;  
        'Adjust pupil diameter (trimming volume inner hole) N4^5rrkL  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" !UV5zmS  
    $*~Iu%Az  
        ' Adjust pupil location to just in front of the lens 7CvD'QW /  
        parID = FindFullName( "Geometry.Arizona Eye" ) c"gsB!xh  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #j@OLvXh  
        count = 0 "Q+83adY4x  
        While GetOperationCount(eID)>count V*jsq[q=  
            GetOperation eID, count, op ,ul5,ygA  
            If op.Type="ShiftZ" Then >`V}U*}*H  
                DeleteOperation eID,count pe04#zQK  
                count=count-1   &LQ%  
            End If #I\Y= XCY  
            count=count+1 A{,n;;  
        Wend Z/ bB h  
        op.Type = "ShiftZ" ?;7b*Z  
        op.val1 = taq-0.01 iL?iz?+.%@  
        op.parent = parID )c tr"&-  
        AddOperation eID, op @ Gjny BJ  
    v ahoSc;sw  
        Print "Set pupil diameter = " & pupilDiam y62%26 [  
    sy<iKCM\  
        'Update AZ Eye subassembly Description lxb8xY  
        eID = FindFullName( "Geometry.Arizona Eye" ) 2wh#$zGy  
        GetEntity eID, entity XQ;I,\m  
        entity.Description = "Accommodation = " & A & "D" H/cTJ9zz  
        SetEntity eID, entity z?.(3oLT  
    k khE}qSD  
        Update -Wo15O"  
        Print "DONE!" ,-#GX{!  
         M'jXve(=yF  
    End Sub K}x/ BhE+  
    BnEdv8\,&s  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 9Vh_[^bR  
    ( )|3  
    Accommodation = 4 Diopters 6M><(1fT  
    Pupil Diameter = 4 mm Rl@$xP  
    Set aqueous humor thickness = 2.81 [e4![G&y`  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 }C~]=Z  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 "n- pl  
    Set lens thickness = 3.927 8 $ ~3ra  
    Set lens index of refraction = 1.42672 .H;B=nd*  
    Set pupil diameter = 4 <f%/px%1  
    DONE! Cd~LsdKE5  
    B?(4f2yE  
    (文章来源:讯技光电)
     
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