[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 pK<%<dIc  
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。 T7^ulG1'  
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模型 (eki X*y  
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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。 ;v%Q8  
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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. {ip=iiW2  
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光源 " \`BPN  
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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。 fVG$8tB  
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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。 p}96uaC1  
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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。 lt{lHat1  
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视网膜的散射 p(~Y" H  
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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。 (D0C#<4P  
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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。 <9ePi9D(  
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脚本 f#'8"ff*1  
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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： Jq=00fcT+  
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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。 /_$~rW  
余下的脚本计算与屈光度有关的所有参数。 6e-#XCR{  
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分析 #L_@s d  
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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。 ;3 G~["DA  
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脚本代码 Oyi;bb<#  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. }l,T~Pjb  
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Dim entity As T_ENTITY &=v/VRan[  
Dim op As T_OPERATION *eHA: A_I  
Dim mat As T_MODELMATERIAL H(X+.R,Thp  
Dim A As Double u^}7Vs .  
Dim pupilDiam As Double fn1 ?Qp|  
Dim eID As Long 4C l,Iw/;  
Dim parID As Long =#OHxM  
Dim count As Integer xP8iz?6"V  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double :hC {5!|  
Dim tlens As Double, nlens As Double @`w'   
Dim curv As Double, conic As Double W2}%zux  
Dim ok As Long Xy[4f=X}z  
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Sub Main B0-4ZT  
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    '用户输入对话框 0t5Q9#RY  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 RnMBGxa  
        TextBox 220,21,40,21,.TextBox1 'default: 0 a/`c ef  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 6Y;Y}E  
        OKButton 40,91,90,21 4a(g<5wfI  
        CancelButton 190,91,90,21 Z
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :SpG&\+  
        TextBox 220,49,40,21,.TextBox2 'default: 4 *]{9K  
    End Dialog &,W_#l{  
    Dim dlg As UserDialog "\VW.S  
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    ok = Dialog (dlg) 4q\.I+r^  
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    If ok=0 Then    'cancel button was pressed ^tm++  
        Print "Execution cancelled." l(h;e&9x  
        End L LYHr  
    End If iYO wB'z  
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    'Assign accommodation and pupil diameter & use defaults if field left empty a<OCO0irJ  
    If dlg.TextBox1 = "" Then N oX_?  
        A = 0           'Default accommodation @D.R0uM  
    Else v YRt2({}Z  
        A = CDbl(dlg.TextBox1) Z]mM  
    End If N&0uXrw  
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    If dlg.TextBox2 = "" Then ,omp F$%  
        pupilDiam = 4   'Default pupil diameter g5kYyE  
    Else MZUF! B  
        pupilDiam = CDbl(dlg.TextBox2) d8Q_6(Ar|  
    End If $\YLmG  
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    Print " " ,Az`6PW  
    Print "Accommodation = " & A & " Diopters" :GwSs'$O  
    Print "Pupil Diameter = " & pupilDiam & " mm" *_4n2<W$  
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    ' Calculate new parameters with accommodation m wRLzN  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Pe+ 8~0o=R  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens nLFx/5sL  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens *j_fG$10g  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens yNhscAMNn  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens !7IT~pO`  
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    tlens = 3.767 + 0.04*A                  'Lens thickness / K_e;(Y_  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Se^/V
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    'Adjust parameters to account for accommodation b
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    '************************************************************************* X]JpS  
    'Aqueous thickness (Position of Lens) p:[`%<j0  
    '************************************************************************* 4! Oa4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;+r)j"W  
    GetCustomElement eID, entity )AnlFO+V  
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    parID = FindFullName( "Geometry.Arizona Eye" ) wZ]BY;  
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    ' Delete any shift(s) in z L#7)X5a__  
    count = 0 F$6])F  
    While GetOperationCount(eID)>count S1H47<)UF  
        GetOperation eID, count, op Kh:#S|
  
        If op.Type="ShiftZ" Then L6[rvM|9_  
            DeleteOperation eID,count G!e}j @@  
            count=count-1 sl^s9kx;C$  
        End If \4\\575zp'  
        count=count+1 E+^} B/"  
    Wend (2O} B.6  
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    'Set new shift in 7'{Yz  
    op.Type = "ShiftZ" BuEQ^[Ex  
    op.val1 = taq |L.~Amd  
    op.parent = parID (Qx-KRH  
    AddOperation eID, op /,rF$5G,  
    Print "Set aqueous humor thickness = " & taq-0.55 aV?}+Y{#  
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    '************************************************************************* Lilk8|?#W  
    'Radius and conic constant of anterior lens ^O$[Y9~*  
    '************************************************************************* ~P]HG;$?n  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) sh
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    GetConic eID, entity, curv, conic o%4&1^ Vg  
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    SetConic eID, entity, 1/Rant, CCant wCq)w=,  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant TN |{
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    '************************************************************************* WnJLX ^;  
    'Radius and conic constant of posterior lens  &aevR^f+  
    '************************************************************************* f1
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) XY+au
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    GetConic eID, entity, curv, conic N}l]Ilm$34  
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    SetConic eID, entity, 1/Rpost, CCpost l9ifUhe  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost n6%jhv9H  
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    '************************************************************************* .~A"Wyu\  
    'Lens thickness (Position of posterior lens surface) *nsnX/e(-  
    '************************************************************************* 2LxVt@_R!%  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :`>+f.)  
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    ' Delete any z-shift(s) o$blPTN  
    count = 0 &Xl_sDvt  
    While GetOperationCount(eID)>count YW$x:  
        GetOperation eID, count, op od5w9E.  
        If op.Type="ShiftZ" Then UB&S 2
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            DeleteOperation eID,count J%Z)#  
            count=count-1 SbPjU50  
        End If O 44IH`SI  
        count=count+1 TJw.e/  
    Wend B'gk/^6$eg  
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    'Set new z-shift Q5Ghki  
    op.Type = "ShiftZ" S^Wqa:;  
    op.val1 = tlens Ji}IV  
    op.parent = parID bF Y)o Z  
    AddOperation eID, op [q>i  
    Print "Set lens thickness = " & tlens <R~~yW:H  
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    '************************************************************************* ^cmP  
    'Lens index of refraction FvI0 J  
    '************************************************************************* HyX4ob[X  
    eID = FindMaterial( "Lens" ) t!=~5YgKs  
    GetModelMaterial eID, mat |7'yk__m  
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    mat.Nd = nlens -< dMD_  
    SetModelMaterial eID, mat )V$!  
    Print "Set lens index of refraction = " & nlens l#vw L15  
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    '************************************************************************* XFf+efh  
    'Pupil diameter sO4}kxZ  
    '************************************************************************* g2 {?EP  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ZhbY,wJ
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    'Adjust pupil diameter (trimming volume inner hole) NK#"qK""k  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" b{|/J<Fe  
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    ' Adjust pupil location to just in front of the lens 'ZZWH  
    parID = FindFullName( "Geometry.Arizona Eye" ) q(ET)xCeD  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) )|^<woli,  
    count = 0 >->xhlL*  
    While GetOperationCount(eID)>count b}U&bFl  
        GetOperation eID, count, op ]I' xLh`  
        If op.Type="ShiftZ" Then "1`i]Y\'  
            DeleteOperation eID,count ,Qi|g'a  
            count=count-1 %K7EF_%  
        End If DdS3<3]A  
        count=count+1 O<d?'{  
    Wend I^\bS  
    op.Type = "ShiftZ" / -qt}  
    op.val1 = taq-0.01 gZ>orZL'  
    op.parent = parID M>H^<N}'A  
    AddOperation eID, op [U7,\o4w  
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    Print "Set pupil diameter = " & pupilDiam }L7F g%,  
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    'Update AZ Eye subassembly Description p$o&dQ=n[  
    eID = FindFullName( "Geometry.Arizona Eye" ) =
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    GetEntity eID, entity <QW1fE  
    entity.Description = "Accommodation = " & A & "D" f}ij=Y9  
    SetEntity eID, entity RJsG]`  
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    Update :2Rci`lp  
    Print "DONE!" ?O>JtEz~lQ  
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End Sub yY-t4WeXP  
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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： 2l/5i]Tq  
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Accommodation = 4 Diopters y~ 4nF  
Pupil Diameter = 4 mm ecI 2]aKi  
Set aqueous humor thickness = 2.81 ,Yprk%JT  
Set anterior lens radius = 10.4 and conic constant = -2.375869 otH[?c?BT  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 M*@aA XM  
Set lens thickness = 3.927 u{nWjqrM*5  
Set lens index of refraction = 1.42672 78inh
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Set pupil diameter = 4 v4a4*rBI"  
DONE! U <$xp  
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