[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 \U$:/#1Oe  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 kO\ O$J^S  
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模型 hS,&Nj+  
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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。 WML--<dU  
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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. M8~3 0L  
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光源 uN)c!='I  
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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。 hVF^"$  
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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。 (I~
  
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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。 VO0:4{-  
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视网膜的散射 N-K/jY  
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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。 *\XOQWrF  
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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。 "OenYiz  
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脚本 M=raKb?F  
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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： tpGT~Y(  
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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。 ;<M}ZL@m  
余下的脚本计算与屈光度有关的所有参数。 uA#K59E+  
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分析 oJ4HvrUO  
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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。 gHPJiiCv  
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脚本代码 )7 Mss/2T  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used.  @*eY~  
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Dim entity As T_ENTITY :Dty([  
Dim op As T_OPERATION &za }THm  
Dim mat As T_MODELMATERIAL )7& -DI1  
Dim A As Double 9I/l+IS"X  
Dim pupilDiam As Double +g g_C'"  
Dim eID As Long TO.b- ;  
Dim parID As Long ]`)5 Qe4  
Dim count As Integer p9)YRLOh.  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double q=W.82.U  
Dim tlens As Double, nlens As Double @
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Dim curv As Double, conic As Double qGA|.I9,  
Dim ok As Long ;d}>8w&tfy  
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Sub Main Q#3}AO  
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    '用户输入对话框 2OJlE) .  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 s;I @En  
        TextBox 220,21,40,21,.TextBox1 'default: 0 svmb~n&x6  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 $0 .6No_|  
        OKButton 40,91,90,21 !K(  
        CancelButton 190,91,90,21 >UCg3uFj  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?XY'<]o E  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Tv"T+!Z  
    End Dialog
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    Dim dlg As UserDialog y7>3hfn~w  
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    ok = Dialog (dlg) ]jD\4\M}  
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    If ok=0 Then    'cancel button was pressed b\0>uU  
        Print "Execution cancelled." Z5'^81m$o  
        End yzK<yvN  
    End If }B'-*)^|e{  
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    'Assign accommodation and pupil diameter & use defaults if field left empty O5r8Ghf)  
    If dlg.TextBox1 = "" Then '!^7 *@z  
        A = 0           'Default accommodation lW?}Ts~'  
    Else )>1}I_1j)  
        A = CDbl(dlg.TextBox1) )IcSdS0@M  
    End If ?7Cm+J  
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    If dlg.TextBox2 = "" Then d'W2I*Zc<  
        pupilDiam = 4   'Default pupil diameter S%MDQTM  
    Else Xr K29a  
        pupilDiam = CDbl(dlg.TextBox2) T{ @@
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    End If &lLk[/b  
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    Print " " 2FuV%\p  
    Print "Accommodation = " & A & " Diopters" B}TY+@  
    Print "Pupil Diameter = " & pupilDiam & " mm" I-^sJ@V;  
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    ' Calculate new parameters with accommodation `"65 _?B i  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ^gcB+  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens !M8_PC*a  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens YA pC|R,^  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ~u$cX1M  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9KX% O-'  

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    tlens = 3.767 + 0.04*A                  'Lens thickness /!
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction @K
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    'Adjust parameters to account for accommodation ~TH4='4W3  
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    '************************************************************************* iYBc4'X  
    'Aqueous thickness (Position of Lens) 0JtM|Mg  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) J
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    GetCustomElement eID, entity I8!>7`L  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 6MM\nIU)/  
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    ' Delete any shift(s) in z )!0}<_2  
    count = 0  jfK&CA  
    While GetOperationCount(eID)>count Tl yyJ{~  
        GetOperation eID, count, op 8TpYt)]S  
        If op.Type="ShiftZ" Then =)Hu
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            DeleteOperation eID,count >bWpj8Kv  
            count=count-1 ;@S'8  
        End If WD\Yx~o  
        count=count+1 $B?8\>_?  
    Wend %ud-3u52M8  
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    'Set new shift in 0p.MH~mx  
    op.Type = "ShiftZ" 4*Hzys[{  
    op.val1 = taq Rw `ezC#  
    op.parent = parID 8SRUqe[H]  
    AddOperation eID, op ^Lb\k|U,\  
    Print "Set aqueous humor thickness = " & taq-0.55 X~&8^?  
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    '************************************************************************* 0?ab'vYcp  
    'Radius and conic constant of anterior lens q`PA~C];  
    '************************************************************************* jR}EBaI}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) pNd`fV#jX  
    GetConic eID, entity, curv, conic :q3w;B~  
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    SetConic eID, entity, 1/Rant, CCant )U|V|yem'  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Gjeb)Y6N  
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    '************************************************************************* ym5@SBqIx  
    'Radius and conic constant of posterior lens .aO6Y+Y  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @+t|Aa^g  
    GetConic eID, entity, curv, conic ! (lF#MG}  
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    SetConic eID, entity, 1/Rpost, CCpost Es#:0KH].v  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Z":m(}u O  
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    '************************************************************************* 5uG^`H@X  
    'Lens thickness (Position of posterior lens surface) 3.Mpd  
    '************************************************************************* .lj5pmD  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4A"nm6  
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    ' Delete any z-shift(s) ?i_
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    count = 0 #Pk{emYW  
    While GetOperationCount(eID)>count F|6"-*[RS  
        GetOperation eID, count, op I}u\ov_Su  
        If op.Type="ShiftZ" Then 5\zR>Tg".  
            DeleteOperation eID,count s%y<FXUj  
            count=count-1 5JaLE5-  
        End If h-"q <eY"  
        count=count+1 ':}9>B3 S  
    Wend K:-jn}i?/  
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    'Set new z-shift +dLUq2  
    op.Type = "ShiftZ" M 2| k.  
    op.val1 = tlens n;. M5}O  
    op.parent = parID ,&3+w~Ua  
    AddOperation eID, op p:b{>lM  
    Print "Set lens thickness = " & tlens Oto8?4[n  
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    '************************************************************************* >{(c\oMD  
    'Lens index of refraction du}HTrsC  
    '************************************************************************* -[vw 8  
    eID = FindMaterial( "Lens" ) 3}g>/F~  
    GetModelMaterial eID, mat 2HVqJib4Yn  
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    mat.Nd = nlens }@6yROy.  
    SetModelMaterial eID, mat !Z>,dN  
    Print "Set lens index of refraction = " & nlens -*[)CR-{  
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    '************************************************************************* QqF*SaO>  
    'Pupil diameter i@6g9\x+  
    '************************************************************************* 0LC]%x+"  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )
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    'Adjust pupil diameter (trimming volume inner hole) :(OV{ u  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 6(?@B^S>2  
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    ' Adjust pupil location to just in front of the lens Am3j:|>*  
    parID = FindFullName( "Geometry.Arizona Eye" ) o$->|k  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) A #SO}c  
    count = 0 Na]Z%#~  
    While GetOperationCount(eID)>count 4MDVR/Z7  
        GetOperation eID, count, op K)l*$h&-  
        If op.Type="ShiftZ" Then R~A))
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            DeleteOperation eID,count >cjxu9Vr1K  
            count=count-1  h8p{  
        End If ZTqt4H  
        count=count+1 H/[(T%]o  
    Wend S.iUiS"  
    op.Type = "ShiftZ" ,1|=_M31  
    op.val1 = taq-0.01 hiVDN"$$  
    op.parent = parID v@2?X4n  
    AddOperation eID, op QHje}  
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    Print "Set pupil diameter = " & pupilDiam 8KP  
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    'Update AZ Eye subassembly Description ~ cu+QR)  
    eID = FindFullName( "Geometry.Arizona Eye" ) p}GTOJT}  
    GetEntity eID, entity OmK0-fa/  
    entity.Description = "Accommodation = " & A & "D" 2y$DTMu  
    SetEntity eID, entity xzMpTZQ  
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    Update nx`W!|g$`  
    Print "DONE!" {hO|{vz  
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End Sub jMR9E@>~E  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： %^I
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Accommodation = 4 Diopters )('{q}JxV  
Pupil Diameter = 4 mm 7~MWp4.  
Set aqueous humor thickness = 2.81 DT;;4-{  
Set anterior lens radius = 10.4 and conic constant = -2.375869 YE"MtL {  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 T8T,G4Q  
Set lens thickness = 3.927 '@hnqcqXq  
Set lens index of refraction = 1.42672 RC"xnnIJv  
Set pupil diameter = 4 |
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DONE! :/Y4I)'  
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