[技术]Arizona眼睛模型 [复制链接]

简介 fBv: TC%  
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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。 kLU-4W5t  
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模型 VfP\)Rl
 
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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。 uN>5Eh&=Pf  
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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. 0_MtmmL.  
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光源 '\xE56v)F  
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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。 \x]\W#C  
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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。 v}d)uPl};  
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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。 `M 'tuQ M  
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视网膜的散射 72yJv=G  
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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。 .8!\6=iJB  
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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。 A8Fe@$<#8  
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脚本 yGAFQ|+  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： Xo/H+[;X  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 &0-oi Y  
余下的脚本计算与屈光度有关的所有参数。 "NGfT:HV  
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分析 /W BmR R  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 6uFw+Ya#  
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脚本代码 aK@ Y) Ju'  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. m:[I$b6AY  
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Dim entity As T_ENTITY 9*ZlNZ  
Dim op As T_OPERATION 9,`i[Dzp  
Dim mat As T_MODELMATERIAL a
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Dim A As Double R)Arr77  
Dim pupilDiam As Double /3~L#
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Dim eID As Long ~i>DF`w$  
Dim parID As Long prz COw  
Dim count As Integer x"NQatdq  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double U{M3QOF  
Dim tlens As Double, nlens As Double ?{B5gaU9F  
Dim curv As Double, conic As Double nM2<u[{gF  
Dim ok As Long NGl 8*Af
 
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Sub Main ~a`[p
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    '用户输入对话框 __.MS6"N  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 C:5-h(#  
        TextBox 220,21,40,21,.TextBox1 'default: 0 qfE0J;e   
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 u*)/e9C  
        OKButton 40,91,90,21 i:0v6d
  
        CancelButton 190,91,90,21 K8X7IE  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 J~]@#=,v  
        TextBox 220,49,40,21,.TextBox2 'default: 4 =N\; ?eF(  
    End Dialog L4m Vk  
    Dim dlg As UserDialog xS/W}-dPv  
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    ok = Dialog (dlg) iiIns.V  
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    If ok=0 Then    'cancel button was pressed +?o!"SJ  
        Print "Execution cancelled." e!*]y&W  
        End ?0qD(cfx<  
    End If [-_{3qq<e  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 'QT~o-U  
    If dlg.TextBox1 = "" Then Y|fD)zG_  
        A = 0           'Default accommodation K!&W}_@l  
    Else BA2"GJvfIA  
        A = CDbl(dlg.TextBox1) HdqB B
  
    End If {k_\1t(/  
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    If dlg.TextBox2 = "" Then [:cD  
        pupilDiam = 4   'Default pupil diameter bt)C+|i  
    Else : "|/  
        pupilDiam = CDbl(dlg.TextBox2) *O~y6|U?  
    End If <.n,:ir  
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    Print " " F~ 5,-atDM  
    Print "Accommodation = " & A & " Diopters" )-)rL@s.  
    Print "Pupil Diameter = " & pupilDiam & " mm" x:MwM?  
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    ' Calculate new parameters with accommodation F%|P#CaB  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness *zrGrk:l  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens HfVHjF)  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens @Z ==B%`  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens -a)1L'R  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens )Ri!  
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    tlens = 3.767 + 0.04*A                  'Lens thickness f%o[eW#  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 'cpm 4mT  
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    'Adjust parameters to account for accommodation MRt"#CO  
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    '************************************************************************* sWr;%<K  
    'Aqueous thickness (Position of Lens) (NLw#)?  
    '************************************************************************* `&D#P%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) x!_5/  
    GetCustomElement eID, entity E,6|-V;?  
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    parID = FindFullName( "Geometry.Arizona Eye" ) >SDQ@63E?  
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    ' Delete any shift(s) in z T$D(Y`zdn  
    count = 0 }9"''Z  
    While GetOperationCount(eID)>count $\NqD:fgb  
        GetOperation eID, count, op S=r0tao,!v  
        If op.Type="ShiftZ" Then -n9&W  
            DeleteOperation eID,count x8@ 4lxj  
            count=count-1 T-a>k.}y  
        End If ?A|JKOst]  
        count=count+1 00 x-  
    Wend T5u71C_wmt  
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    'Set new shift in t<` As6}  
    op.Type = "ShiftZ" "KP]3EyPc  
    op.val1 = taq <4Gy~?  
    op.parent = parID RdPk1?}K  
    AddOperation eID, op l%EvXdZuOy  
    Print "Set aqueous humor thickness = " & taq-0.55 GFdbwn5B  
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    '************************************************************************* _l7_!Il_  
    'Radius and conic constant of anterior lens >*{k~Y-G  
    '************************************************************************* 'd$R
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~-zIB=TyK  
    GetConic eID, entity, curv, conic W\zZ&*8$  
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    SetConic eID, entity, 1/Rant, CCant jV}8VK*`+  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant r"2lcNE  
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    '************************************************************************* m:h6J''<Z*  
    'Radius and conic constant of posterior lens BFW b0;+  
    '************************************************************************* ,kJ7c;:i  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) a|z-EKV  
    GetConic eID, entity, curv, conic PN93.G(W  
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    SetConic eID, entity, 1/Rpost, CCpost v%qOW)].  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost y-3'qq'E  
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    '************************************************************************* + kMj|()>\  
    'Lens thickness (Position of posterior lens surface) )=Z;H"_  
    '************************************************************************* 7zH2dqrj  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" )
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    ' Delete any z-shift(s) ikc1,o  
    count = 0 N-upNuv  
    While GetOperationCount(eID)>count gFp3=s0~  
        GetOperation eID, count, op Yc]V+NxxQ  
        If op.Type="ShiftZ" Then <ZSXOh,'  
            DeleteOperation eID,count lq:q0>vyI  
            count=count-1 3cghg._  
        End If @~$d4K y<  
        count=count+1 ] x)>q  
    Wend R/v|ZvI  
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    'Set new z-shift ;F258/J  
    op.Type = "ShiftZ" &AJ bx  
    op.val1 = tlens our ^J8
  
    op.parent = parID QWOPCoUet  
    AddOperation eID, op 3tf_\E+mIi  
    Print "Set lens thickness = " & tlens u"qu!EY2  
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    '************************************************************************* sR9$=91`  
    'Lens index of refraction CBd%}il  
    '************************************************************************* )<V!lsUx'-  
    eID = FindMaterial( "Lens" ) {%3WHGr%L  
    GetModelMaterial eID, mat Vx<{cHQQ  
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    mat.Nd = nlens s8,YQ5-  
    SetModelMaterial eID, mat &5-1Cd E  
    Print "Set lens index of refraction = " & nlens 73X*|g  
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    '************************************************************************* 5.5kH$;>  
    'Pupil diameter Hes!uy  
    '************************************************************************* Ll=G+cw6P  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) .F7?}8>Z  
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    'Adjust pupil diameter (trimming volume inner hole) # QwX|x{  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ~}b0zL  
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    ' Adjust pupil location to just in front of the lens j:cu;6|  
    parID = FindFullName( "Geometry.Arizona Eye" ) >;Hx<FKxP  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) }SWfP5D@  
    count = 0 A>gZl)c  
    While GetOperationCount(eID)>count .fzyA5@l  
        GetOperation eID, count, op F8?,}5j  
        If op.Type="ShiftZ" Then =Lkn   
            DeleteOperation eID,count (m2%7f.I  
            count=count-1 IB# u
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        End If ^4`x:6m  
        count=count+1 TI3xt-/  
    Wend M%_*vD  
    op.Type = "ShiftZ" /UunWZ u%  
    op.val1 = taq-0.01 9!=4}:+  
    op.parent = parID A]m*~Vj]  
    AddOperation eID, op N>3{!K>/Y:  
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    Print "Set pupil diameter = " & pupilDiam vx?KenO}  
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    'Update AZ Eye subassembly Description %6(\Ki6I  
    eID = FindFullName( "Geometry.Arizona Eye" ) {BlTLAKm  
    GetEntity eID, entity <y?+xZM]#|  
    entity.Description = "Accommodation = " & A & "D" \{<ml n  
    SetEntity eID, entity &5K3AL  
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    Update ?H8w;Csq-  
    Print "DONE!" (QIU3EN  
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End Sub e-`9-U%6  
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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： VJ-t#q"  
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Accommodation = 4 Diopters s@~3L  
Pupil Diameter = 4 mm "oxUKT  
Set aqueous humor thickness = 2.81 \ &|xMw[  
Set anterior lens radius = 10.4 and conic constant = -2.375869 f ] *w1  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 b [HnhAI  
Set lens thickness = 3.927 vULDKJNHX  
Set lens index of refraction = 1.42672 l1zPL3"u_^  
Set pupil diameter = 4 / P@P1l|I  
DONE! xb[yy}>"L