[技术]Arizona眼睛模型 [复制链接]

简介 42>Ge>#F  
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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。 P{Q=mEQ  
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模型 UT}i0I9  
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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。 `9k0Gd  
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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. /b|0PMX  
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光源 k+1|I)z  
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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。 )Ud-}* g  
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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。 1:Si,d,wh  
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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。 %LYnxo7#C  
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视网膜的散射 a~8[<Fomj  
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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。 NH_<q"gT  
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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。 3]?#he  
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脚本 T6ENtp  
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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： 3P;>XGCxZ  
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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。 }`+B=h-dW  
余下的脚本计算与屈光度有关的所有参数。 D-N8<:cA  
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分析  ^eoLAL  
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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。 IUtx!.]4  
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脚本代码 p<:!)kt  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Qyy.IPTP  
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Dim entity As T_ENTITY awz;z?~  
Dim op As T_OPERATION "+unS)M;Y  
Dim mat As T_MODELMATERIAL 6d+p7x  
Dim A As Double $v Z$'(  
Dim pupilDiam As Double O`vTnrY  
Dim eID As Long *YlV-C<}W"  
Dim parID As Long a@R]X5[O  
Dim count As Integer Uo2GK3nT  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^i:B+ rl  
Dim tlens As Double, nlens As Double h>Hb`G<  
Dim curv As Double, conic As Double ~RWktv  
Dim ok As Long
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Sub Main @]ao"ui@/  
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    '用户输入对话框 o;?/HE%,[  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 QD%L0;j  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ~}<DG1!  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ZI=v.wa  
        OKButton 40,91,90,21 T*KMksjxm`  
        CancelButton 190,91,90,21 @lvyDu6e  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 PiA0]>  
        TextBox 220,49,40,21,.TextBox2 'default: 4 jRL<JZ1N  
    End Dialog )&!&AlLn  
    Dim dlg As UserDialog :^(>YAyHj^  
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    ok = Dialog (dlg) QV\eMuNy  
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    If ok=0 Then    'cancel button was pressed NQ6sGL  
        Print "Execution cancelled." NC38fiH_N  
        End >;[*!<pfK5  
    End If tToTxf~  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ~ yX2\i"  
    If dlg.TextBox1 = "" Then
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        A = 0           'Default accommodation w4gg@aO  
    Else !/wtYI-`  
        A = CDbl(dlg.TextBox1) IC7M$  
    End If k1!@^A  
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    If dlg.TextBox2 = "" Then ,2W8=ON  
        pupilDiam = 4   'Default pupil diameter MNV% =G  
    Else Gn&4V}F  
        pupilDiam = CDbl(dlg.TextBox2) hodgDrmO/  
    End If X*\J_  
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    Print " " )vSRHE  
    Print "Accommodation = " & A & " Diopters" S;- LIv  
    Print "Pupil Diameter = " & pupilDiam & " mm" L+i(TM=  
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    ' Calculate new parameters with accommodation y~\oTJb  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness LSRk7'0  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens *I0T{~  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens g pOC`=  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens %QP0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens `V04\05  
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    tlens = 3.767 + 0.04*A                  'Lens thickness j{Q9{}<e  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 0ik7v<:  
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    'Adjust parameters to account for accommodation ^t#&@-'(d  
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    '************************************************************************* l~$+,U&XNe  
    'Aqueous thickness (Position of Lens) %B.yW`,X  
    '************************************************************************* J G{3EWXR  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) _BP&n  
    GetCustomElement eID, entity #n8IZ3+
  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ;67x0)kn  
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    ' Delete any shift(s) in z 73\JwOn~  
    count = 0 [
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    While GetOperationCount(eID)>count k5kxQhPf  
        GetOperation eID, count, op +O?KNZ  
        If op.Type="ShiftZ" Then ]&Rx@&e*  
            DeleteOperation eID,count ys
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            count=count-1 OD!
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        End If ?BZPwGMs  
        count=count+1 ybKWOp:O  
    Wend  UWo]s.  
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    'Set new shift in :BV6y|J9O^  
    op.Type = "ShiftZ" $arK(  
    op.val1 = taq m()RU"WY  
    op.parent = parID !*B'?|a<\  
    AddOperation eID, op
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    Print "Set aqueous humor thickness = " & taq-0.55 ia+oX~W!VR  
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    '************************************************************************* '$ t  
    'Radius and conic constant of anterior lens LAS'u"c|  
    '************************************************************************* fO[+LR 'ax  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) hJpxf,?'K  
    GetConic eID, entity, curv, conic Eu@huN*/  
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    SetConic eID, entity, 1/Rant, CCant "4{LN}`  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 2Tp1n8FV  
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    '************************************************************************* A
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    'Radius and conic constant of posterior lens ,N]H dR  
    '************************************************************************* r w2arx  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) sl`s_$J  
    GetConic eID, entity, curv, conic NRIG1v>  
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    SetConic eID, entity, 1/Rpost, CCpost l:,'j@%  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost VKG&Y_7N  
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    '************************************************************************* Enn"hdI  
    'Lens thickness (Position of posterior lens surface) /)}
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    '************************************************************************* E%,^Yvh/  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) xg;+<iW  
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    ' Delete any z-shift(s) f=r<n
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    count = 0 %Q fO8P  
    While GetOperationCount(eID)>count Y4`}y-'d  
        GetOperation eID, count, op YA_c N5p/@  
        If op.Type="ShiftZ" Then koZ*+VP=  
            DeleteOperation eID,count bB1UZ O  
            count=count-1 d\|?-hY`[  
        End If )f[ B6Y  
        count=count+1 0uOkMuy<  
    Wend "!ug_'VW  
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    'Set new z-shift AQ,' 6F9  
    op.Type = "ShiftZ" |@ s,XS  
    op.val1 = tlens K}buH\yco  
    op.parent = parID ^6MU 0Q2  
    AddOperation eID, op !Sh&3uy_qN  
    Print "Set lens thickness = " & tlens 4C61GB?Vy  
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    '************************************************************************* |y!=J$$_H  
    'Lens index of refraction ZojIR\F^  
    '************************************************************************* [B#R94  
    eID = FindMaterial( "Lens" ) 93("oBd[s(  
    GetModelMaterial eID, mat \IV1j)I"u  
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    mat.Nd = nlens 8D3OOab  
    SetModelMaterial eID, mat j,lT>/  
    Print "Set lens index of refraction = " & nlens .f%fHj  
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    '************************************************************************* =jOv] /  
    'Pupil diameter RKHyw08  
    '************************************************************************* Z'`gJ&6n  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Pq;U&,  
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    'Adjust pupil diameter (trimming volume inner hole) }Gz~nf%  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |:q=T ~x  
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    ' Adjust pupil location to just in front of the lens (C-{B[Y  
    parID = FindFullName( "Geometry.Arizona Eye" ) )t0$qd ]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *4Thd:7 `  
    count = 0 mZtCL  
    While GetOperationCount(eID)>count z;{iM/Xe  
        GetOperation eID, count, op ); !eow  
        If op.Type="ShiftZ" Then s C%&cRQD  
            DeleteOperation eID,count `w#Oih!6A|  
            count=count-1 d6}r#\  
        End If TJ_$vI  
        count=count+1 0=@?ob7  
    Wend `<``8  
    op.Type = "ShiftZ" E4`
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    op.val1 = taq-0.01 "CSsCA$/  
    op.parent = parID ddJQC|xR}  
    AddOperation eID, op !;&p"E|b#  
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    Print "Set pupil diameter = " & pupilDiam we~[] \  
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    'Update AZ Eye subassembly Description
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    eID = FindFullName( "Geometry.Arizona Eye" ) :~b3^xhc^  
    GetEntity eID, entity Xb:;</  
    entity.Description = "Accommodation = " & A & "D" m,*QP*  
    SetEntity eID, entity ?*[N_'2W+  
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    Update 5,3'=mA6  
    Print "DONE!" >:AARx%  
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End Sub 8##-EN;ag  
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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#vVD3"  
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Accommodation = 4 Diopters oX#Q<2z*  
Pupil Diameter = 4 mm 3 R=,1<  
Set aqueous humor thickness = 2.81 ]e"=$2d$  
Set anterior lens radius = 10.4 and conic constant = -2.375869 nOt&pq7  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 oRm L {UDZ  
Set lens thickness = 3.927 KSbKEA  
Set lens index of refraction = 1.42672 *]ly0nP  
Set pupil diameter = 4 YZLkL26[  
DONE! %q/62f7?