[技术]Arizona眼睛模型 [复制链接]

简介 _7
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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_S8m|%  
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模型 WbC|2!
 
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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。 =8S*t
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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. $},Y)"mI  
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光源 GFasGHAw  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 <CIJ
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 z><=F,W  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 22S4q`j  
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视网膜的散射 3a #2 }  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 nsFOtOdd  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。  f.acH]p  
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脚本 Y`jvza%  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 89T xd9X  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 U 2am1}  
余下的脚本计算与屈光度有关的所有参数。 *4#)or  
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分析 nN1\  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 JVbR5"+.  
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脚本代码 m` ^o<V&  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. *TQXE:vZ[  
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Dim entity As T_ENTITY "L^]a$&  
Dim op As T_OPERATION 9TRS#iVL+*  
Dim mat As T_MODELMATERIAL l&l&
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Dim A As Double NrH2U Jm  
Dim pupilDiam As Double yJ*`OU#  
Dim eID As Long d_s=5+Yj  
Dim parID As Long ApHs`0=(  
Dim count As Integer {`,dWjy{%  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double i]&C=X  
Dim tlens As Double, nlens As Double 5%,5Xe4p  
Dim curv As Double, conic As Double $SAq/VHI1]  
Dim ok As Long dbM~41C6  
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Sub Main AjBwj5K  
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    '用户输入对话框 ?'ID7mL  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 "D#+:ix8G|  
        TextBox 220,21,40,21,.TextBox1 'default: 0 {FRUB(68b  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |Iei!jm  
        OKButton 40,91,90,21 ~I[Z2&I  
        CancelButton 190,91,90,21 q6DuLFatc*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 278:5yC  
        TextBox 220,49,40,21,.TextBox2 'default: 4 iAD'MB  
    End Dialog D2N| A  
    Dim dlg As UserDialog u^.7zL+  
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    ok = Dialog (dlg) ~q]@Jp  
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    If ok=0 Then    'cancel button was pressed N$>.V7H&  
        Print "Execution cancelled." >g7}JI&  
        End r}351S5(  
    End If /+^7lQo\]  
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    'Assign accommodation and pupil diameter & use defaults if field left empty '}#=I 9=ss  
    If dlg.TextBox1 = "" Then kaM=Fk=t  
        A = 0           'Default accommodation %N5gQXg  
    Else fz/Ee1T\  
        A = CDbl(dlg.TextBox1) C\"nlNKw  
    End If iF]G$@rbU  
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    If dlg.TextBox2 = "" Then a#3+PB#  
        pupilDiam = 4   'Default pupil diameter <Y%km[Mh  
    Else {"{kWbXZ  
        pupilDiam = CDbl(dlg.TextBox2) "&h{+DHS  
    End If '-9B`O,&  
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    Print " " ]q!,onJ  
    Print "Accommodation = " & A & " Diopters" xvo""R/g8  
    Print "Pupil Diameter = " & pupilDiam & " mm" \S#Mc  
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    ' Calculate new parameters with accommodation %L;z~C  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness h8Wv t's  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens o[=h=&@5p  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens K4w %XVaH  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens I*h%e,yIO  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens %3p~5jhm1  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 2rxZN\gyL  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction sKE7U>mz|  
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    'Adjust parameters to account for accommodation .`w[A  
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    '************************************************************************* X8(H#Ef[  
    'Aqueous thickness (Position of Lens) cf\PG&S  
    '************************************************************************* vP k\b 3E  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) YoC{ t&rY  
    GetCustomElement eID, entity h\qQ%|X  
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    parID = FindFullName( "Geometry.Arizona Eye" ) .kbo]P  
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    ' Delete any shift(s) in z ]IF QD  
    count = 0 ?HD eiJkX  
    While GetOperationCount(eID)>count TNi4H:\  
        GetOperation eID, count, op A=N &(k  
        If op.Type="ShiftZ" Then 8]G  
            DeleteOperation eID,count ~Qg:_ @@\  
            count=count-1 <H; z4  
        End If tccw0  
        count=count+1 W#|30RU.G  
    Wend LgG7|\(-  
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    'Set new shift in L>trLD1pt  
    op.Type = "ShiftZ" R=7,F6.  
    op.val1 = taq adCT
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    op.parent = parID *8I+D>x  
    AddOperation eID, op B|fh 4FNy  
    Print "Set aqueous humor thickness = " & taq-0.55 )Z/L  
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    '************************************************************************* AiF'*!1  
    'Radius and conic constant of anterior lens N~=,RPjq  
    '************************************************************************* jH5VrN*Q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) N}|<P[LW  
    GetConic eID, entity, curv, conic /Jcf
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    SetConic eID, entity, 1/Rant, CCant pxGDzU  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant -(oFO'Lbg  
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    '************************************************************************* "Y1]6 Zu  
    'Radius and conic constant of posterior lens k vuSE  
    '************************************************************************* ^i"~6QYE  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) :m&cm%W]ts  
    GetConic eID, entity, curv, conic xr*%:TwCta  
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    SetConic eID, entity, 1/Rpost, CCpost ~10>mg  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost (GCeD-  
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    '************************************************************************* ;q"Yz-3  
    'Lens thickness (Position of posterior lens surface) Y5/SbQYf1  
    '************************************************************************* %&Fsk]T%:  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Yl$R$u)  
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    ' Delete any z-shift(s) |_h$}~;  
    count = 0 @$*LU:[  
    While GetOperationCount(eID)>count q,Nhfo(  
        GetOperation eID, count, op u4KP;_,m  
        If op.Type="ShiftZ" Then &^7^7:Y=?  
            DeleteOperation eID,count 4Ou5Vp&y  
            count=count-1 S- N [  
        End If \jpm   
        count=count+1 2{Johqf  
    Wend K*/X{3J;  
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    'Set new z-shift \/8oua_)  
    op.Type = "ShiftZ" Sb|9U8h  
    op.val1 = tlens au;ZAXM|  
    op.parent = parID o,q47W=7$  
    AddOperation eID, op vVyX[
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    Print "Set lens thickness = " & tlens xb (Cd  
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    '************************************************************************* ll^#I/  
    'Lens index of refraction c$fYK  
    '************************************************************************* xX:N-  
    eID = FindMaterial( "Lens" ) HZl//Uq  
    GetModelMaterial eID, mat 2mt S\bAF  
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    mat.Nd = nlens FhFP M)[  
    SetModelMaterial eID, mat ,7/F?!G!J  
    Print "Set lens index of refraction = " & nlens #*tWhXU  
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    '************************************************************************* F8pP(Wl  
    'Pupil diameter U3tA"X.K  
    '************************************************************************* 1"fbQ^4`  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) U{Xx)l/o  
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    'Adjust pupil diameter (trimming volume inner hole) "Nh}_jO  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Q13>z%Rge  
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    ' Adjust pupil location to just in front of the lens *>,#'C2  
    parID = FindFullName( "Geometry.Arizona Eye" ) Z[GeU>?P  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) HxnWM\p  
    count = 0 .Gcs/PN  
    While GetOperationCount(eID)>count 9NE
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        GetOperation eID, count, op &57s//PrX  
        If op.Type="ShiftZ" Then k.6gX<T  
            DeleteOperation eID,count +\s&v!  
            count=count-1 2S@aG%-)  
        End If &fRZaq'2R  
        count=count+1 1=Y pNXX  
    Wend TD^w|U.  
    op.Type = "ShiftZ" p->b Vt  
    op.val1 = taq-0.01 ;hZ^zL  
    op.parent = parID N6<
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    AddOperation eID, op *V[6ta
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    Print "Set pupil diameter = " & pupilDiam ~\o hH  
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    'Update AZ Eye subassembly Description 5~H}%W,P  
    eID = FindFullName( "Geometry.Arizona Eye" ) iji2gWV}h  
    GetEntity eID, entity |HfN<4NL  
    entity.Description = "Accommodation = " & A & "D" I%'6IpR"d  
    SetEntity eID, entity h7 c  
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    Update i"GCm`  
    Print "DONE!" #Nv)SCc  
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End Sub %Q.|qyq  
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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： XM:Y(#?l  
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Accommodation = 4 Diopters ?>T (  
Pupil Diameter = 4 mm m-AW}1:\f  
Set aqueous humor thickness = 2.81 ){FXonVP  
Set anterior lens radius = 10.4 and conic constant = -2.375869 @lu`oyM  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 LG:Mksd8=4  
Set lens thickness = 3.927 MzpDvnI9  
Set lens index of refraction = 1.42672 ,cwjieM  
Set pupil diameter = 4 th]pqhl>  
DONE! F&)(G\