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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 {LzH&qu  
    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。 {XurC}#\  
    58xnB!h\}  
    模型  u6u=2  
    YcX/{L[9o  
    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。  kzmQm  
    zSvgKmNY  
    Table 1. AZ眼睛模型的定义
    =DbY?Q<Q  
    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. vl E z9/H  
    SzD KByi  
    光源 d5 Edu44  
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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。 tMx}*l|]  
    BKa- k!  
    #:x4DvDkR  
    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。 SAV%4  
    qm*}U3K  
    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。 0yM[Z':i'{  
    H5cV5E0  
    图2. 字母F光源的设定方法光 c?2MBtnu  
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    图3. 字母F在视网膜上位置点列图
    :K82sCy%5  
    视网膜的散射 aA`/E  
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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。 =,!\~`^  
    gwd (N  
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    图4. 视网膜朗伯散射设定
    ;^Sr"v6r>u  
    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。 VQI(Vp|  
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    图5. 视网膜重点采样规格设定
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    脚本 AGP("U'u  
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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: }U w&Ny  
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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
    Fk;o E'"D  
    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。 g$:Xuw1  
    余下的脚本计算与屈光度有关的所有参数。 5m:i6,4  
    }{9&:!uA  
    分析 <mMTD8Sx]  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 t2" (2  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 + 1IQYa|  
    I V%VU  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. \AUI|M;'  
     8@{OR"Ec  
    Dim entity As T_ENTITY 4Tc&IwR  
    Dim op As T_OPERATION y %$O-q  
    Dim mat As T_MODELMATERIAL r,goRK.  
    Dim A As Double 7+TiyY]K  
    Dim pupilDiam As Double qjAWeS/  
    Dim eID As Long _sE#)@p  
    Dim parID As Long depYqYK7G  
    Dim count As Integer ]9=h%5Ji>  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double B<8N96fx  
    Dim tlens As Double, nlens As Double Mr--4D0Hk  
    Dim curv As Double, conic As Double ;g_> ;tR/  
    Dim ok As Long 1pv}]&X  
    %u^ JpC{E  
    Sub Main MC((M,3L  
    vkS)E0s  
        '用户输入对话框  rdnno  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 XS0xLt=  
            TextBox 220,21,40,21,.TextBox1 'default: 0 22<0DhJ  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 3lLMu B+  
            OKButton 40,91,90,21 0c.s -  
            CancelButton 190,91,90,21 ~m1P_`T  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 6ZgU"!|r  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Glq85S  
        End Dialog OX%MP!#KU  
        Dim dlg As UserDialog Iq+>qX   
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        ok = Dialog (dlg) $wYtyN[  
    @cRZk`|1n  
        If ok=0 Then    'cancel button was pressed xR"M*%{@0  
            Print "Execution cancelled." +5.t. d  
            End z|?R/Gf8  
        End If S.B<pj gt  
    @`-[;?>  
        'Assign accommodation and pupil diameter & use defaults if field left empty gx03xPeu  
        If dlg.TextBox1 = "" Then 4`Nt{  
            A = 0           'Default accommodation B .TB\j  
        Else '6$*YN&5  
            A = CDbl(dlg.TextBox1) kVI#(uO  
        End If q(5j(G ;  
    B,z<%DAE  
        If dlg.TextBox2 = "" Then 1[*UYcD  
            pupilDiam = 4   'Default pupil diameter wdzOFDA  
        Else '^%~JyU  
            pupilDiam = CDbl(dlg.TextBox2) #QvMVy  
        End If wiOgyMdx  
    d|Gl`BG   
        Print " " ; )Kh;;e  
        Print "Accommodation = " & A & " Diopters" AeIrr*~]B  
        Print "Pupil Diameter = " & pupilDiam & " mm" dX8hpQ  
    PCd0 ?c   
        ' Calculate new parameters with accommodation *xf._~E  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 41#w|L \  
    =H0vE7{*  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens @4%L36k  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens VhT= l  
    xE}VTHFo'  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Ub0/r$]DK  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ej&<GM|  
    L_Q#(in  
        tlens = 3.767 + 0.04*A                  'Lens thickness |vte=)%  
    Z') pf  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 9 7%0;a8  
    I O%6 O  
        'Adjust parameters to account for accommodation cN! uV-e  
    3`O?16O  
        '************************************************************************* ~mV"i7VX  
        'Aqueous thickness (Position of Lens) Bhqft;Nuh  
        '************************************************************************* s57N) 0kP  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) }14 {2=!Q  
        GetCustomElement eID, entity U(&oj e  
    N-lGa@ j  
        parID = FindFullName( "Geometry.Arizona Eye" ) rdJm{<  
    zJa)*N  
        ' Delete any shift(s) in z [LT^sb  
        count = 0 ogM%N  
        While GetOperationCount(eID)>count |eoid?=  
            GetOperation eID, count, op #5sD{:f`  
            If op.Type="ShiftZ" Then qP!eJ6[Nh"  
                DeleteOperation eID,count Xqp|VbDca  
                count=count-1 &a!BD/  
            End If ?!w^`D0}o  
            count=count+1 ,~ ?'Ef80  
        Wend j^`X~gE  
    v,NHQyk  
        'Set new shift in ?[ly`>KpJ  
        op.Type = "ShiftZ" Y**|N8e  
        op.val1 = taq "%WgT2)m.  
        op.parent = parID Ap&)6g   
        AddOperation eID, op U5Erm6U:  
        Print "Set aqueous humor thickness = " & taq-0.55 < (RC|?  
    :&}odx!-!C  
        '************************************************************************* g1(Xg.  
        'Radius and conic constant of anterior lens K.tlo^#^B[  
        '************************************************************************* q<e&0u4  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Mr+@c)  
        GetConic eID, entity, curv, conic ZZ/cq:3$P  
    ;S$Ll*f>D  
        SetConic eID, entity, 1/Rant, CCant 9L%I<5i  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant zHB_{(o7  
    ocwG7J\W  
        '************************************************************************* sK$wN4k  
        'Radius and conic constant of posterior lens RnVtZ#SCh  
        '************************************************************************* s*M@%_A?  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 3HG;!D~m;  
        GetConic eID, entity, curv, conic %k f>&b,Mi  
    VeiElU3  
        SetConic eID, entity, 1/Rpost, CCpost WV;=@v  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [{[N(g&d  
    W:&R~R  
        '************************************************************************* wbbqt0un  
        'Lens thickness (Position of posterior lens surface) %/"Oxi^G  
        '************************************************************************* pvWau1ArNq  
    XCB?ll*^  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) CDMfa&;T  
    ;sdN-mb  
        ' Delete any z-shift(s) ,reJ(s  
        count = 0 # jYpVc{]  
        While GetOperationCount(eID)>count s}M= oe  
            GetOperation eID, count, op }pNX@C#De  
            If op.Type="ShiftZ" Then @}FAwv^f  
                DeleteOperation eID,count xtV[p4U  
                count=count-1 yT OyDm-  
            End If 4FeEGySow  
            count=count+1 8$P>wCK\l  
        Wend 1ZJ4*bn  
    9G?ldp8  
        'Set new z-shift AH7L.L+$M  
        op.Type = "ShiftZ" H{ M)-  
        op.val1 = tlens =?}twC$  
        op.parent = parID )9"oL!2h  
        AddOperation eID, op U SOKDDm  
        Print "Set lens thickness = " & tlens S[M4ukYK  
    u.|~   
        '************************************************************************* UP1?5Q=H]Q  
        'Lens index of refraction d<p2/aA  
        '************************************************************************* 7l8[xV  
        eID = FindMaterial( "Lens" ) O0~vf[i];  
        GetModelMaterial eID, mat l4'~}nn(Y  
    _v5t<_^N  
        mat.Nd = nlens Aw ^yH+ae  
        SetModelMaterial eID, mat Os),;W0w4  
        Print "Set lens index of refraction = " & nlens #5CI)4x0!  
    :1fagaPg  
        '************************************************************************* -<f/\U  
        'Pupil diameter H>7dND 2;  
        '************************************************************************* AMlV%U#  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <)m%*9{  
    "Tbnxx]J  
        'Adjust pupil diameter (trimming volume inner hole) G"s0GpvQ  
    tn<6:@T  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 'UwI*EW2S  
    Rc$h{0K8  
        ' Adjust pupil location to just in front of the lens w8M2N]&:  
        parID = FindFullName( "Geometry.Arizona Eye" ) q|#MB7e/  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) _+QwREP  
        count = 0 ``4wX-y  
        While GetOperationCount(eID)>count 9/TY\?U  
            GetOperation eID, count, op Eek9|i"p  
            If op.Type="ShiftZ" Then GG-[`!>.pw  
                DeleteOperation eID,count 3P=w =~e  
                count=count-1 ?T*";_o,B  
            End If >Wi s.e%b  
            count=count+1 -f>'RI95>  
        Wend x !{   
        op.Type = "ShiftZ" +cg {[f,J;  
        op.val1 = taq-0.01 R9dP,<2  
        op.parent = parID [B/0-(?  
        AddOperation eID, op z]#hWfM4B:  
    h8}8Lp(/'  
        Print "Set pupil diameter = " & pupilDiam (O5)wej   
    Wc'Ehyi;  
        'Update AZ Eye subassembly Description A3UQJ  
        eID = FindFullName( "Geometry.Arizona Eye" ) S ~|.&0"\  
        GetEntity eID, entity !oMt_k X  
        entity.Description = "Accommodation = " & A & "D" X , ZeD  
        SetEntity eID, entity tHI*,  
    Vewzo1G2  
        Update =MSu3<y,  
        Print "DONE!" R2^iSl%pj  
         F$Pp]"82'm  
    End Sub kV)' a  
    :m`/Q_y"  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 4;<DJ.XlN=  
    ])$S\fFm  
    Accommodation = 4 Diopters 1D1b"o  
    Pupil Diameter = 4 mm |~$7X  
    Set aqueous humor thickness = 2.81 'j79GC0  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 a-PGW2G  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 c4|so=  
    Set lens thickness = 3.927 &'O?es|Lb  
    Set lens index of refraction = 1.42672 0|C[-ppr  
    Set pupil diameter = 4 z\}!RBOq  
    DONE! 8~5|KO >F  
    u%opY<h  
    (文章来源:讯技光电)
     
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