[技术]Arizona眼睛模型 [复制链接]

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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。 t,_[nu(~8%  
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模型 7j8_O@_  
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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。 dGe  
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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. T~>:8i  
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光源 [qB=OxH?  
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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。 =_Rd0,  
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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。 5]E5V@C
 
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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。 FmPF7  
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视网膜的散射 DNPK1e3a{  
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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。 x{E[qH_1Fm  
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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。 q2y:bqLWl  
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脚本 UWHC]V?  
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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： <OUAppH  
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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。 _~!,x.Dbp  
余下的脚本计算与屈光度有关的所有参数。 8'y|cF%U  
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分析 L<:ya  
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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。 #!2gxm;g  
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脚本代码 4
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. rTH@PDk>)  
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Dim entity As T_ENTITY m#Cp.|>kP4  
Dim op As T_OPERATION )~6974  
Dim mat As T_MODELMATERIAL NoMC*",b>  
Dim A As Double 3]'3{@{}H  
Dim pupilDiam As Double 7Ny>W(8  
Dim eID As Long ?@~FT1"6G  
Dim parID As Long q9OIw1xQr*  
Dim count As Integer SV.*Z|"^N  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double QwhP
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Dim tlens As Double, nlens As Double wdg[pt />  
Dim curv As Double, conic As Double HBt?cA '  
Dim ok As Long Y, P-@(  
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Sub Main 2dC)%]aLme  
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    '用户输入对话框 X**w
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ^C(AMT  
        TextBox 220,21,40,21,.TextBox1 'default: 0 k
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 BjA|H  
        OKButton 40,91,90,21 CTwP{[%Pk  
        CancelButton 190,91,90,21 8w{V[@QLn  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k=LY 6  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ?B-aj  
    End Dialog 9`xq3
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    Dim dlg As UserDialog 3}"VUS0wh  
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    ok = Dialog (dlg) toF@@%  
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    If ok=0 Then    'cancel button was pressed ar6Z?v$  
        Print "Execution cancelled." a@%FwfIu  
        End qB8<(vBP+  
    End If ^0r@",  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 6:e0?R^aD"  
    If dlg.TextBox1 = "" Then 1r;Q5[@  
        A = 0           'Default accommodation dZZ
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    Else pM>.z
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        A = CDbl(dlg.TextBox1) L|c01  
    End If oL<^m?-u  
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    If dlg.TextBox2 = "" Then .9`.\v6R  
        pupilDiam = 4   'Default pupil diameter l!`m}$  
    Else 7Q^
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        pupilDiam = CDbl(dlg.TextBox2) g
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    End If nF7Ozxm#  
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    Print " " OrzDr  
    Print "Accommodation = " & A & " Diopters" \wTWhr0  
    Print "Pupil Diameter = " & pupilDiam & " mm" C<{k[!N%zm  
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    ' Calculate new parameters with accommodation 9X!OQxmg  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness =s;7T!7!  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens eQMY3/#  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,UY],;ib  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens vRm;H|[%S  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens J.~$^
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    tlens = 3.767 + 0.04*A                  'Lens thickness ;X\,-pjv  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction x H\5T!  
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    'Adjust parameters to account for accommodation Zsaz#z|xW  
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    '************************************************************************* {gzL}KL  
    'Aqueous thickness (Position of Lens) y6;A4p>  
    '************************************************************************* ZE4~rq/W  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {D$#m  
    GetCustomElement eID, entity zxXm9zrLo  
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    parID = FindFullName( "Geometry.Arizona Eye" ) _8kZ>w(L  
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    ' Delete any shift(s) in z 1H%LUA  
    count = 0 Ow<=K:^  
    While GetOperationCount(eID)>count 5_{C \S`T  
        GetOperation eID, count, op g;vG6!;E\  
        If op.Type="ShiftZ" Then ?PLf+S  
            DeleteOperation eID,count `5Q0U%`W  
            count=count-1 &Zd!|u  
        End If K`D>
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        count=count+1 Wcw$ Zv  
    Wend !fjDO!,!  
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    'Set new shift in ?~hC.5  
    op.Type = "ShiftZ" c:M~!CXO  
    op.val1 = taq X&pK#=  
    op.parent = parID zJOL\J'  
    AddOperation eID, op YrFB~z.V  
    Print "Set aqueous humor thickness = " & taq-0.55 3 rV)
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    '************************************************************************* wm!Y5  
    'Radius and conic constant of anterior lens SVo:%mX  
    '************************************************************************* hgLwxJu  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {+!m]-s  
    GetConic eID, entity, curv, conic Ak^g#^c*  
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    SetConic eID, entity, 1/Rant, CCant 5_9mA4gs@  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant L slI!.(  
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    '************************************************************************* 
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    'Radius and conic constant of posterior lens h%9#~gJ})  
    '************************************************************************* 1!~=8FTv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +QGZ2_vW  
    GetConic eID, entity, curv, conic \x5b=~/
 
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    SetConic eID, entity, 1/Rpost, CCpost 7='lu;=,  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost gDa}8!+i  
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    '************************************************************************* Z.ky=vCt  
    'Lens thickness (Position of posterior lens surface) 1/:WA:]1,  
    '************************************************************************* 1Ue)&RW  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) KLrxlD4\  
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    ' Delete any z-shift(s) W_8N?coM  
    count = 0 SvLI%>B
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    While GetOperationCount(eID)>count $F"'=+0  
        GetOperation eID, count, op Nr8#/H2f  
        If op.Type="ShiftZ" Then SfLZVB  
            DeleteOperation eID,count b"DaLwKkz  
            count=count-1 V{+'(<SV  
        End If LVP2jTz  
        count=count+1 fP# !ywgr%  
    Wend LX2rg\a+%  
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    'Set new z-shift Dukvi;\  
    op.Type = "ShiftZ" 6}4?,r  
    op.val1 = tlens 3}~.#`QeY  
    op.parent = parID N@6+DH
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    AddOperation eID, op wyJ
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    Print "Set lens thickness = " & tlens G'<:O(Imu  
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    '************************************************************************* nI]8w6eCV  
    'Lens index of refraction cuzU*QW"g  
    '************************************************************************* A{X:p3$eN  
    eID = FindMaterial( "Lens" ) AtU%S9  
    GetModelMaterial eID, mat xU<WUfS1  
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    mat.Nd = nlens n.is+2t  
    SetModelMaterial eID, mat PgHe;^?j  
    Print "Set lens index of refraction = " & nlens m#w1?y)Z@X  
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    '************************************************************************* |z1er"zR)  
    'Pupil diameter /5M0[C E  
    '************************************************************************* *WMI<w~_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) >V1vw7Pa  
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    'Adjust pupil diameter (trimming volume inner hole) Jj%"
  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" o0ky]9 P  
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    ' Adjust pupil location to just in front of the lens jEhPx  
    parID = FindFullName( "Geometry.Arizona Eye" ) %vn"tp  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^cRAtoa  
    count = 0 A; _Zw[  
    While GetOperationCount(eID)>count qh9d.Q+n  
        GetOperation eID, count, op F-R5Ib-F*A  
        If op.Type="ShiftZ" Then (>]frlEU~  
            DeleteOperation eID,count gpT~3c;l=  
            count=count-1 eYtP396C|  
        End If Z-%zR'-?*  
        count=count+1 JsP<etX  
    Wend iy!SqC  
    op.Type = "ShiftZ" [/=Z2mtA  
    op.val1 = taq-0.01 C*X=nezq  
    op.parent = parID L0\~K~q  
    AddOperation eID, op i8w/a  
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    Print "Set pupil diameter = " & pupilDiam i1dE.f;  
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    'Update AZ Eye subassembly Description MD98N{+[|  
    eID = FindFullName( "Geometry.Arizona Eye" ) mP*Ct6628n  
    GetEntity eID, entity 1u8 k}  
    entity.Description = "Accommodation = " & A & "D" $U=j<^R}a  
    SetEntity eID, entity :%[mc-6.  
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    Update -#Bk  
    Print "DONE!" jhR`%a
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End Sub z{H=;"+rh  
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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： eC{St0  
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Accommodation = 4 Diopters WhT5NE9t  
Pupil Diameter = 4 mm b9;w3Ba  
Set aqueous humor thickness = 2.81 p!o-+@ava  
Set anterior lens radius = 10.4 and conic constant = -2.375869 z[Ah9tM%  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 A('o&H  
Set lens thickness = 3.927 `O0bba=:=  
Set lens index of refraction = 1.42672 %63s(ekU  
Set pupil diameter = 4 
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DONE! :u]QEZ@@