[技术]Arizona眼睛模型 [复制链接]

简介 )-[$m%  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 akr2Os  
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模型 }(u:K}8  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 Xykoq"dbb  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. &Wa3/mWK  
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光源 NbU4|Oi  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 vd#)+  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 .yfp-n4H  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 (kO(R#M  
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视网膜的散射 C1_0 9Vc  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 l:@=9Fp>  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 QlB9m2XB  
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脚本 |$IL:W6  
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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： hC"'cUrcN  
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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。 j<!dpt  
余下的脚本计算与屈光度有关的所有参数。 qm/>\4eLt  
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分析 $2*_7_Qb  
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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。 s%R,]q  
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脚本代码 xC9?rLUZ  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ;lE=7[UJ3X  
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Dim entity As T_ENTITY TT(R<hL  
Dim op As T_OPERATION Pw]+6  
Dim mat As T_MODELMATERIAL -J6`  
Dim A As Double a3M
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Dim pupilDiam As Double .?APDr"QQH  
Dim eID As Long )d3C1Pd>  
Dim parID As Long (p#c p  
Dim count As Integer ~kV>nx2  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double *wx%jbJo  
Dim tlens As Double, nlens As Double $Lfbt=f  
Dim curv As Double, conic As Double 8q]"CFpa  
Dim ok As Long H~#$AD+H  
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Sub Main C[Q4OAFG  
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    '用户输入对话框 &?p(UY7'"  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 =os!^{p7>  
        TextBox 220,21,40,21,.TextBox1 'default: 0 8M
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 p)Q5fh0-  
        OKButton 40,91,90,21 {G3Ok++hc  
        CancelButton 190,91,90,21 uIO?4\s&G  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 J80&npsO  
        TextBox 220,49,40,21,.TextBox2 'default: 4 i4>M  
    End Dialog z7?SuJ  
    Dim dlg As UserDialog njJTEUd">  
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    ok = Dialog (dlg) KRd'!bG=1  
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    If ok=0 Then    'cancel button was pressed 6*$A/D  
        Print "Execution cancelled." EGv]K|  
        End qh}+b^Wi  
    End If .i )K#82  
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    'Assign accommodation and pupil diameter & use defaults if field left empty @JdeOL;  
    If dlg.TextBox1 = "" Then l_04b];  
        A = 0           'Default accommodation ,'YKL",  
    Else 2\64~a^  
        A = CDbl(dlg.TextBox1) %sZ3Gpi  
    End If elKp?YN  
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    If dlg.TextBox2 = "" Then +DefV,Ny  
        pupilDiam = 4   'Default pupil diameter JY:Fu  
    Else "
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        pupilDiam = CDbl(dlg.TextBox2) rKOa9M  
    End If JB5%\  
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    Print " " X}={:T+6s  
    Print "Accommodation = " & A & " Diopters" 753gcY#i  
    Print "Pupil Diameter = " & pupilDiam & " mm" lxD~l#)^ln  
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    ' Calculate new parameters with accommodation $b^niL  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness x)%"i)  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens v'`qn  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens sy(bL_%  

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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens (?T{^Hg  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Um-Xb'R*]V  
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    tlens = 3.767 + 0.04*A                  'Lens thickness %qrUP\rn  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction n sN n>{  
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    'Adjust parameters to account for accommodation \G/ZA) t  
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    '************************************************************************* `5x0p a  
    'Aqueous thickness (Position of Lens) h6`VU`pPI  
    '************************************************************************* ^{8CShUCv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) IK4(r /  
    GetCustomElement eID, entity *ZRk)  
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    parID = FindFullName( "Geometry.Arizona Eye" ) *r~6R
  
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    ' Delete any shift(s) in z JNvgUb'U  
    count = 0 b'/:e#F  
    While GetOperationCount(eID)>count KeyHxU=?  
        GetOperation eID, count, op
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        If op.Type="ShiftZ" Then eXLdb-  
            DeleteOperation eID,count U~zy;MT  
            count=count-1 5Ktll~+:#  
        End If `J{{E,y @  
        count=count+1 "KC3+
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    Wend ?WS.RBe2  
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    'Set new shift in {FC<vx{42  
    op.Type = "ShiftZ" *`bES V :  
    op.val1 = taq +).=}.k  
    op.parent = parID 0@&;JMh6<  
    AddOperation eID, op !.q#X^@>L  
    Print "Set aqueous humor thickness = " & taq-0.55 _|{pO7x]oG  
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    '************************************************************************* IMy!8$\u  
    'Radius and conic constant of anterior lens $qoal   
    '************************************************************************* !0X"^VB  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) !83 N#Y_Mz  
    GetConic eID, entity, curv, conic p+2%LYR u  
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    SetConic eID, entity, 1/Rant, CCant [S.zWPX9{  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant p5nrPL  
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    '************************************************************************* Yka>r9wr  
    'Radius and conic constant of posterior lens VhgcvS@V  
    '************************************************************************* X5Y. o&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) LXc;`]  
    GetConic eID, entity, curv, conic q6 4bP4K  
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    SetConic eID, entity, 1/Rpost, CCpost 2m&?t_W  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost # o\&G@e}  
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    '*************************************************************************  t|:XSJ9  
    'Lens thickness (Position of posterior lens surface) |'L$ogt6  
    '************************************************************************* /cD]m  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) _[hVGCS
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    ' Delete any z-shift(s) H"V)dEm  
    count = 0 BQ!_i*14+  
    While GetOperationCount(eID)>count <$nMqUu0  
        GetOperation eID, count, op z&|sks7  
        If op.Type="ShiftZ" Then <2w41QZX  
            DeleteOperation eID,count lIatM@gU  
            count=count-1 s:sk`~2<gd  
        End If WTC/mcS  
        count=count+1 0t00X/  
    Wend z-kB!~r  
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    'Set new z-shift /.1h_[K]  
    op.Type = "ShiftZ" O~F8lQ  
    op.val1 = tlens ZV:0:k.x  
    op.parent = parID N..@}}  
    AddOperation eID, op 1ZfhDtK(  
    Print "Set lens thickness = " & tlens Zu^J X/um  
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    '************************************************************************* TUR2|J@n  
    'Lens index of refraction _ 3jY,*  
    '************************************************************************* Ni61o?]Nj  
    eID = FindMaterial( "Lens" ) MSS0Sx<f  
    GetModelMaterial eID, mat a#P
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    mat.Nd = nlens OQsF$%*  
    SetModelMaterial eID, mat AkV8}>G?#A  
    Print "Set lens index of refraction = " & nlens KrD?Z2x  
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    '************************************************************************* <o_(,,P%  
    'Pupil diameter f.u+({"ql  
    '************************************************************************* ^WIGd"^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) dmE.yVI"O  
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    'Adjust pupil diameter (trimming volume inner hole) " [K>faV  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" o[K,(  
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    ' Adjust pupil location to just in front of the lens Q>>II|~;J  
    parID = FindFullName( "Geometry.Arizona Eye" ) VH$hQPP5d  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) >[gNQJ6  
    count = 0 xw&N[y5  
    While GetOperationCount(eID)>count !qVnziE,,  
        GetOperation eID, count, op 2t"&>1  
        If op.Type="ShiftZ" Then *`wgqin  
            DeleteOperation eID,count y[sO0u\  
            count=count-1 i;}mIsNBY  
        End If \TXCq@  
        count=count+1 #x5?RHX56  
    Wend qCgoB 0  
    op.Type = "ShiftZ" 97L#3L6t  
    op.val1 = taq-0.01 +HNM$yp  
    op.parent = parID H~r":A'"*  
    AddOperation eID, op "iTi+UZxe  
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    Print "Set pupil diameter = " & pupilDiam &>%9JXU  
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    'Update AZ Eye subassembly Description yMbg1+:   
    eID = FindFullName( "Geometry.Arizona Eye" ) XhG3Of-6  
    GetEntity eID, entity $[DSe~  
    entity.Description = "Accommodation = " & A & "D" )wueR5P  
    SetEntity eID, entity T:(c/>  
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    Update _mn2bc9M  
    Print "DONE!" Z`Sbq{Kx  
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End Sub w [7vxQ!-  
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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： x 2Cp{+}  
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Accommodation = 4 Diopters eJwHeG  
Pupil Diameter = 4 mm DDwm
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Set aqueous humor thickness = 2.81 VgyY7INx9  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ]:r6
 
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ]KE"|}B  
Set lens thickness = 3.927 M|xs>+r*  
Set lens index of refraction = 1.42672 MGE8
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Set pupil diameter = 4 _/`H<@B_U  
DONE! E|v9khN(].