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    [转载]FRED运用:Arizona眼睛模型 [复制链接]

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    离线xunjigd
     
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    只看楼主 倒序阅读 楼主  发表于: 2016-02-24
    简介 [qO5~E`;  
    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。 U]`'GM/x  
    F:[Nw#gj/  
    模型 b<29wL1  
    wsdB; 6%$  
    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。 !3b|*].B  
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    Table 1. AZ眼睛模型的定义
    Qd&d\w/  
    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.  :V5!C$QV  
    tS_xa  
    光源 /h}wM6pg  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 )sqp7["-  
    ~#IWM+I  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 mTrI""Jsu;  
    8S[ <[CH  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 @4W\RwD  
    V)WIfRs  
    图2. 字母F光源的设定方法光 cAsSN.HFS  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 >h/)r6  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 M; S-ESQ  
    :3E8`q~c1  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 ^Xt]wl*]+  
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    图5. 视网膜重点采样规格设定
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    脚本 FzsS~C$wH{  
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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: g O\f:Pg  
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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。 q)z1</B-  
    余下的脚本计算与屈光度有关的所有参数。 v0H>iKh7  
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    分析 BHRrXC\  
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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。 }ii]c Y  
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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 DY+8m8!4H  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7:R{~|R  
    [jtj~]&mO  
    Dim entity As T_ENTITY 3Oig/KZ  
    Dim op As T_OPERATION 6&xW9' 6b:  
    Dim mat As T_MODELMATERIAL Jj^<:t5{rN  
    Dim A As Double 5sV/N] !  
    Dim pupilDiam As Double Ph7(JV{  
    Dim eID As Long T$8$9D_u  
    Dim parID As Long "`1of8$X7  
    Dim count As Integer e&a[k  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double [2H(yLwO  
    Dim tlens As Double, nlens As Double W<Vzd4hR  
    Dim curv As Double, conic As Double iw]B QjK  
    Dim ok As Long WY. \<$7  
    hz~CW-47  
    Sub Main q NQ3(1xW  
    DHujpZXQ  
        '用户输入对话框 7yCx !P;  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 qwq+?fj={  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Wp9 2sm+  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 G~$M"@Q7N  
            OKButton 40,91,90,21 ]@<3 6ByM  
            CancelButton 190,91,90,21 |@bNd7=2d  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?PxYS%D_L  
            TextBox 220,49,40,21,.TextBox2 'default: 4 *mhw5Z=!  
        End Dialog RT+30Q?  
        Dim dlg As UserDialog f6_|dvY3  
    lt(-,md  
        ok = Dialog (dlg) 4`5Qt=}  
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        If ok=0 Then    'cancel button was pressed Vwh&^{Eh  
            Print "Execution cancelled." G>{:D'#  
            End !&:W1Jkp(  
        End If Z-sN4fr a  
    $q@RHcj  
        'Assign accommodation and pupil diameter & use defaults if field left empty dgqJ=+z 0y  
        If dlg.TextBox1 = "" Then 2Z9gOd<M~  
            A = 0           'Default accommodation `R=_t]ie  
        Else :>-sITeY  
            A = CDbl(dlg.TextBox1) 2] wf`9ZH  
        End If ZtK%b+MBP  
    M Ut^mu$86  
        If dlg.TextBox2 = "" Then wbF1>{/"  
            pupilDiam = 4   'Default pupil diameter rxK[CDM,  
        Else [,?A$Z*Z|  
            pupilDiam = CDbl(dlg.TextBox2) AiHDoV+-  
        End If wk <~Y 3u  
    PNxO \Rc  
        Print " " Va[dZeoy  
        Print "Accommodation = " & A & " Diopters" Q\>SF  
        Print "Pupil Diameter = " & pupilDiam & " mm" )*<d1$aM  
    lG^nT  
        ' Calculate new parameters with accommodation 7)It1i-  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness (a4y1k t-  
    D2*Q1n  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens DdZ_2B2  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens o6yZ@R  
    hD.wKX?oO  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens i2R]lE8  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 5N</Z6f'o  
    M #Ru I%  
        tlens = 3.767 + 0.04*A                  'Lens thickness `0vy+T5  
    kk./-G  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ?|rw=%  
    [67f;?b  
        'Adjust parameters to account for accommodation M]zNW{Xt  
     G/;aZ  
        '************************************************************************* Z42Suy  
        'Aqueous thickness (Position of Lens) 0_Z|y/I.  
        '************************************************************************* :qKY@-t7H  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZaV66Y>  
        GetCustomElement eID, entity ?U[nYp}"v  
    ~=]@], {  
        parID = FindFullName( "Geometry.Arizona Eye" ) Gkvd{G?F  
    _[Wrd?Z  
        ' Delete any shift(s) in z 3T^dgWXEG  
        count = 0 >!.lr9(l  
        While GetOperationCount(eID)>count &zDFf9w2{  
            GetOperation eID, count, op p" W0$t.  
            If op.Type="ShiftZ" Then (j Q6~1  
                DeleteOperation eID,count ' "p*FN  
                count=count-1 <g1hdF0  
            End If d'nuk#r  
            count=count+1 rSCX$ @@F  
        Wend B{7/A[$%C  
    Mp}NUQHE  
        'Set new shift in ^u&Khc~ y  
        op.Type = "ShiftZ" ~4gKA D  
        op.val1 = taq $ aBSr1  
        op.parent = parID iz5wUyeg  
        AddOperation eID, op TTak[e&j3  
        Print "Set aqueous humor thickness = " & taq-0.55 lD=j/    
    yp'>+cLa  
        '************************************************************************* JU+'UK630  
        'Radius and conic constant of anterior lens SytDo (_=W  
        '************************************************************************* V!tBipX%  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) eV}Tx;1|}  
        GetConic eID, entity, curv, conic -%$ dFq  
    }r<^]Q*&p  
        SetConic eID, entity, 1/Rant, CCant !sWBj'[>  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant %+J*oFwQu  
    k}qiIMdI  
        '************************************************************************* Av4E ?@R  
        'Radius and conic constant of posterior lens .Q@'Ob`  
        '************************************************************************* Qn&^.e9I  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) J, >PLQAa  
        GetConic eID, entity, curv, conic 4u7>NQUDu  
    bd;f@)X  
        SetConic eID, entity, 1/Rpost, CCpost /hR]aw  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost SXF_)1QO\W  
    sUMn (@r  
        '************************************************************************* '~a$f;: Dv  
        'Lens thickness (Position of posterior lens surface) GQWTQIl]  
        '************************************************************************* a}hM}U!  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) =_3qUcOP  
    (j"MsCwE  
        ' Delete any z-shift(s) %W@IB8]Vr  
        count = 0 _ @76eZd  
        While GetOperationCount(eID)>count feHAZ.8rp+  
            GetOperation eID, count, op YJsi5  
            If op.Type="ShiftZ" Then 6GvnyJ{[  
                DeleteOperation eID,count L@GD$F=<0  
                count=count-1 5(Oc"0''H  
            End If VHNiTp  
            count=count+1 [)u{-  
        Wend &|] ^ u/  
    H4jqF~  
        'Set new z-shift A[a+,TN {  
        op.Type = "ShiftZ" . %7A7a  
        op.val1 = tlens ;O>fy :$'  
        op.parent = parID ?yK\L-ad  
        AddOperation eID, op H:6$) #  
        Print "Set lens thickness = " & tlens :"]ei@  
    }FVX5/.'  
        '************************************************************************* 1fZ:^|\  
        'Lens index of refraction HbVLL`06*  
        '************************************************************************* BZ9iy~  
        eID = FindMaterial( "Lens" ) iSHl_/I<  
        GetModelMaterial eID, mat ?C3cPt"  
    gZv <_0N  
        mat.Nd = nlens ]9Hy "#Fz  
        SetModelMaterial eID, mat EM}z-@A>  
        Print "Set lens index of refraction = " & nlens Z ngJ9js  
    4fswx@l  
        '************************************************************************* K-3 _4As  
        'Pupil diameter g_U69 z  
        '************************************************************************* ev $eM  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) |{T2|iJI  
    _L":Wux  
        'Adjust pupil diameter (trimming volume inner hole) T!bu}KO  
    hLRQ)  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5,C,q%2  
    CCV~nf  
        ' Adjust pupil location to just in front of the lens }|,y`ui\  
        parID = FindFullName( "Geometry.Arizona Eye" ) Hik[pVK@  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) s9iM hCu|  
        count = 0 iq$/ 6!t  
        While GetOperationCount(eID)>count z{\.3G  
            GetOperation eID, count, op 4KCxhJq  
            If op.Type="ShiftZ" Then q]x@q  
                DeleteOperation eID,count tANG ]  
                count=count-1 ]_s]Q_+E  
            End If x<(h9tB  
            count=count+1 @^O ww(I  
        Wend s><co]  
        op.Type = "ShiftZ" &^.'g{\Y  
        op.val1 = taq-0.01 zlfm})+G  
        op.parent = parID 8{C3ijR  
        AddOperation eID, op $4&Ql  
    q<VhP2R  
        Print "Set pupil diameter = " & pupilDiam |w DCIHzQ  
    z( wXs&z;  
        'Update AZ Eye subassembly Description i(WWF#N 5  
        eID = FindFullName( "Geometry.Arizona Eye" ) lK-I[i!  
        GetEntity eID, entity cc[w%jlA#  
        entity.Description = "Accommodation = " & A & "D" /03>|Juo  
        SetEntity eID, entity cF6|IlhO  
    E' Bt1 u  
        Update }1V&(#H2  
        Print "DONE!" C7{wI`~  
         ]l%j>Vb!L  
    End Sub DjIs"5Iei  
    Gkl#s7'  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: KjadX&JD  
    p.G7Cs  
    Accommodation = 4 Diopters > L%%B-  
    Pupil Diameter = 4 mm XL:7$  
    Set aqueous humor thickness = 2.81 !duR7a  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 b7-a0zaN  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 |fUSq1//  
    Set lens thickness = 3.927 ?Rdi"{.wI  
    Set lens index of refraction = 1.42672 <~d N23)  
    Set pupil diameter = 4 4:.M*Dz  
    DONE! wQ5__"D  
    $)U RY~;i  
    (文章来源:讯技光电)
     
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