[技术]Arizona眼睛模型 [复制链接]

简介 ,>bGbx  
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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。 ?qd,>  
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模型 ^eTDD  
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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。 {h
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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. kfMhw M8kP  
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光源 w?]ZU-  
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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。 ~-XOvKJb  
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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。 55 S\&Ad$  
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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。 Qqd6.F  
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视网膜的散射 .ocx(_3G  
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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。 q+YuVQ-fx  
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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。 1 L+=|*:  
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脚本 Ze-MAt  
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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： GE%2/z p  
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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。 uz]E_&2  
余下的脚本计算与屈光度有关的所有参数。 :=rA Yc3]  
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分析 aRbx   
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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。 .qSBh hH\  
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脚本代码 ;(K  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Hl4\M]]/&  
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Dim entity As T_ENTITY
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Dim op As T_OPERATION CXTt(-FT  
Dim mat As T_MODELMATERIAL *i`v~>  
Dim A As Double ]\OWZ{T'j  
Dim pupilDiam As Double !tI=`
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Dim eID As Long A
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Dim parID As Long d4%dIR)  
Dim count As Integer 4py(R-8\  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Y5HfN[u^7  
Dim tlens As Double, nlens As Double I[ai:   
Dim curv As Double, conic As Double HeCcF+  
Dim ok As Long :v`o6x8  
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Sub Main , 7Xqte  
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    '用户输入对话框 (B&h;U$HAH  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 UV4u.7y  
        TextBox 220,21,40,21,.TextBox1 'default: 0 prZ55MS.  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 WE")xhV6  
        OKButton 40,91,90,21 K'NcTw#f  
        CancelButton 190,91,90,21 o w2$o\hC  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 cqEHYJ;B  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ,*dzJT$k  
    End Dialog <{giHT  
    Dim dlg As UserDialog BBvZeG $Y  
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    ok = Dialog (dlg) h2% J/69  
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    If ok=0 Then    'cancel button was pressed $_)=8"Sn  
        Print "Execution cancelled." +jtA&1cf  
        End :
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    End If a"QU:<-v  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 3%^z?_  
    If dlg.TextBox1 = "" Then >\ZR*CS  
        A = 0           'Default accommodation H>.B99vp  
    Else pW{8R^vKm  
        A = CDbl(dlg.TextBox1) %w7m\nw@  
    End If i&A%"lOI9  
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    If dlg.TextBox2 = "" Then rs:Q%V ^  
        pupilDiam = 4   'Default pupil diameter azo0{`S?  
    Else _R7 w?!t8  
        pupilDiam = CDbl(dlg.TextBox2) B;!f<"a8  
    End If )r9b:c\  
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    Print " " :tM?%=Q  
    Print "Accommodation = " & A & " Diopters" c&f y{}10  
    Print "Pupil Diameter = " & pupilDiam & " mm" ANMYX18M  
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    ' Calculate new parameters with accommodation .Pw%DZ'  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness PKA }zZ  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Qw?+!-7TN  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens .^[_V  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens "}b'E#  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 1zjaR4Tf  
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    tlens = 3.767 + 0.04*A                  'Lens thickness K;U39ofW  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction aV>aiR=  
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    'Adjust parameters to account for accommodation WJ+>e+  
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    '************************************************************************* Km3&N  
    'Aqueous thickness (Position of Lens) ([ dT!B#aH  
    '************************************************************************* 3bs4mCq  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :EZQ'3X  
    GetCustomElement eID, entity Ftv8@l  
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    parID = FindFullName( "Geometry.Arizona Eye" ) mJC3@V s  
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    ' Delete any shift(s) in z )NT5yF,m  
    count = 0 ~|lIC !q  
    While GetOperationCount(eID)>count :eOR-}p'  
        GetOperation eID, count, op u@=?#a$$  
        If op.Type="ShiftZ" Then (9$"#o  
            DeleteOperation eID,count Ht[{ryTxu  
            count=count-1 }nud  
        End If jtKn3m7 +p  
        count=count+1 a3@w|KLt  
    Wend aMK~1]Cx  
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    'Set new shift in IfV 3fJ7  
    op.Type = "ShiftZ" Ct]A%=cZW  
    op.val1 = taq [pgZbOIN37  
    op.parent = parID <7n]Ai@Y  
    AddOperation eID, op 8)xt(~qF  
    Print "Set aqueous humor thickness = " & taq-0.55 otr>3a*'  
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    '************************************************************************* SwH2$:f  
    'Radius and conic constant of anterior lens #Hu~}zy  
    '************************************************************************* PlCc8Zy  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) :reTJQwr  
    GetConic eID, entity, curv, conic vR>o}%`  
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    SetConic eID, entity, 1/Rant, CCant )1F<6R  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant h`5)2n+P  
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    '************************************************************************* Bct"X#W|&  
    'Radius and conic constant of posterior lens uQeu4$k!  
    '************************************************************************* QH@>icAb  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) $'"8QOnJ?k  
    GetConic eID, entity, curv, conic *'ZN:5%H  
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    SetConic eID, entity, 1/Rpost, CCpost vtxvS3   
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 2KI!
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    '************************************************************************* O}Le]2'  
    'Lens thickness (Position of posterior lens surface) Bjj<\8^M  
    '************************************************************************* 5bX6#5uP1  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) u oVNK  
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    ' Delete any z-shift(s) S~F`  
    count = 0 p!W[X%`)  
    While GetOperationCount(eID)>count )\0F7Z  
        GetOperation eID, count, op 5/I_w0  
        If op.Type="ShiftZ" Then ,&]MOe4@>  
            DeleteOperation eID,count SR7j\1a/2A  
            count=count-1 Xm_$ dZ  
        End If v[S-Pi1  
        count=count+1 RiFw?Q+  
    Wend l]#!+@  
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    'Set new z-shift 'BqZOZw  
    op.Type = "ShiftZ" wu~hqd  
    op.val1 = tlens wH6u5*$p  
    op.parent = parID k%Vv?{g  
    AddOperation eID, op raB+,Oi$G  
    Print "Set lens thickness = " & tlens 3$p#;a:=n  
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    '************************************************************************* NHaMo*xQ  
    'Lens index of refraction ;b%{ilx:  
    '************************************************************************* XutF"9u  
    eID = FindMaterial( "Lens" ) :FQ1[X1xm  
    GetModelMaterial eID, mat bEH de*q(  
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    mat.Nd = nlens |V&G81sM  
    SetModelMaterial eID, mat 3h=8"lRc  
    Print "Set lens index of refraction = " & nlens pyB~M9Bp/  
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    '************************************************************************* M}F~_S0h  
    'Pupil diameter ;;&F1@3tBa  
    '************************************************************************* r
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Q~,YbZ-7  
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    'Adjust pupil diameter (trimming volume inner hole) mJ  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <,8l *1C  
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    ' Adjust pupil location to just in front of the lens a/:XXy |  
    parID = FindFullName( "Geometry.Arizona Eye" ) m *X7T  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) WS0JS'  
    count = 0 Ex(3D[WmMW  
    While GetOperationCount(eID)>count ;Ss$2V'a  
        GetOperation eID, count, op jX */piSq  
        If op.Type="ShiftZ" Then ;4~U,+Av  
            DeleteOperation eID,count nkY@_N
 
            count=count-1 ;+_8&wbqW  
        End If 3fkk [U  
        count=count+1 PEXq:TA  
    Wend _a'A~JY  
    op.Type = "ShiftZ" 8b&uU [  
    op.val1 = taq-0.01 H7&xLYQ2  
    op.parent = parID (H#M<N  
    AddOperation eID, op FxU'LN<;HY  
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    Print "Set pupil diameter = " & pupilDiam %FA@)?~  
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    'Update AZ Eye subassembly Description T0e<Slo~C  
    eID = FindFullName( "Geometry.Arizona Eye" ) < K%j  
    GetEntity eID, entity O.+9,4A(  
    entity.Description = "Accommodation = " & A & "D" Y94MI1O5$  
    SetEntity eID, entity w G!u+  
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    Update iS: #o>  
    Print "DONE!" =_d%=m  
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End Sub [_!O<z_sB  
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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： Qi=*1QAkr  
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Accommodation = 4 Diopters AFm1t2,+;  
Pupil Diameter = 4 mm shF
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Set aqueous humor thickness = 2.81
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Set anterior lens radius = 10.4 and conic constant = -2.375869 7TWNB{ K_  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 <Oz66bTze  
Set lens thickness = 3.927 L\ j:  
Set lens index of refraction = 1.42672 +x1/-J8_sg  
Set pupil diameter = 4 =uV,bG5V1  
DONE! i/qTFQst _