[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 G9;WO*  
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。 mSs%gL]g  
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模型 $|AxQQ%f  
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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。 0[^f9NZ>-  
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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. k2~j:&p  

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光源 u7K0m! jW  
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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。 z[th@!3  
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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。 |X>:"?4t  
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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。 ~e|~c<!z8@  
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视网膜的散射 =KkHck33  
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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。 {C [7V{4(%  
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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。 koFY7;_<?  
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脚本 vtmvvv  
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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： .hUndg  
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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。 d+$a5 [^9  
余下的脚本计算与屈光度有关的所有参数。 $Ad 5hkz  
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分析 &{99Owqg  
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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。 $5l8V  
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脚本代码 *:wu{3g}M`  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. p "u5wJ_  
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Dim entity As T_ENTITY .xS}/^8iD  
Dim op As T_OPERATION K[O'@v  
Dim mat As T_MODELMATERIAL np
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Dim A As Double b k 30d  
Dim pupilDiam As Double k1W q$KCwG  
Dim eID As Long ex1bjM7  
Dim parID As Long 1 %K^(J;  
Dim count As Integer [;%qxAB/_  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double d H]'&&M  
Dim tlens As Double, nlens As Double "*a^_tsT?i  
Dim curv As Double, conic As Double <GT&q <4w  
Dim ok As Long ZBi|BD  
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Sub Main %&0_0BU  
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    '用户输入对话框 se2ay_<F+  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Cwl#(;@  
        TextBox 220,21,40,21,.TextBox1 'default: 0 6x7pqHM  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 {dTtYL$'"  
        OKButton 40,91,90,21 l*rli[No  
        CancelButton 190,91,90,21 dX?8@uzu  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 1 :<f[l  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Tapj7/0`  
    End Dialog eJlTCXeZ|  
    Dim dlg As UserDialog ED[`Y.;  
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    ok = Dialog (dlg) *DcJ).  
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    If ok=0 Then    'cancel button was pressed v!JQ;OX  
        Print "Execution cancelled." H:TRJ.!w2  
        End W6:ei.d+NS  
    End If WW\t<O;z  
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    'Assign accommodation and pupil diameter & use defaults if field left empty n$&xVaF|  
    If dlg.TextBox1 = "" Then [oqb@J2  
        A = 0           'Default accommodation ~H`~&?  
    Else )%FRBO]  
        A = CDbl(dlg.TextBox1) '[g@A>xDvW  
    End If ZUPlMHc  
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    If dlg.TextBox2 = "" Then N{w)}me[YY  
        pupilDiam = 4   'Default pupil diameter KG=h!]Meq  
    Else H=,0p  
        pupilDiam = CDbl(dlg.TextBox2) G;Jqby8d  
    End If HY|=Z\l"  
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    Print " " no).70K  
    Print "Accommodation = " & A & " Diopters" HuzHXn)  
    Print "Pupil Diameter = " & pupilDiam & " mm" b5NPG N  
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    ' Calculate new parameters with accommodation %\<SSp^n  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 4AA3D!$  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens rRgP/E#_  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens [ed6n@/O@  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 0@ccXFE  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens x"7`,W  
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    tlens = 3.767 + 0.04*A                  'Lens thickness <?h
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction JzI/kH~  
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    'Adjust parameters to account for accommodation Bg3`w__l;  
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    '************************************************************************* A 9\]y%!  
    'Aqueous thickness (Position of Lens) >Z-f</v03  
    '************************************************************************* GO3F[l  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) "'i" @CR  
    GetCustomElement eID, entity (?[^##03MN  
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    parID = FindFullName( "Geometry.Arizona Eye" ) >d1g
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    ' Delete any shift(s) in z Rd#V,[d  
    count = 0
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    While GetOperationCount(eID)>count q4Z9;^S  
        GetOperation eID, count, op s{q)P1x  
        If op.Type="ShiftZ" Then [ QHSCF5  
            DeleteOperation eID,count Qqju6}+  
            count=count-1 oz54IO  
        End If ~ 8hAmM  
        count=count+1 YTWlR]Tr6?  
    Wend R> r@[$z+  
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    'Set new shift in WcE{1&PXx  
    op.Type = "ShiftZ" ctqXzM `  
    op.val1 = taq ~QVN^8WPg  
    op.parent = parID WrzyBG_  
    AddOperation eID, op Nhq&Sn2  
    Print "Set aqueous humor thickness = " & taq-0.55 "'M>%m u  
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    '************************************************************************* <|,0%bq)|  
    'Radius and conic constant of anterior lens DH@})TN*O  
    '************************************************************************* ?=C?3R  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) eJh4hp;x  
    GetConic eID, entity, curv, conic {OK+d#=
 
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    SetConic eID, entity, 1/Rant, CCant ^7cZ9/3  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant s*blZdP  
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    '************************************************************************* N001c)*7Q  
    'Radius and conic constant of posterior lens [;IW'cXNq  
    '************************************************************************* qT U(]O1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) T!GX^nn*O  
    GetConic eID, entity, curv, conic .'+*>y!  
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    SetConic eID, entity, 1/Rpost, CCpost
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [#}A]1N  
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    '************************************************************************* /~k)#44  
    'Lens thickness (Position of posterior lens surface) }YPW@g  
    '************************************************************************* v7;zce/~  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) y-Xd~<*Ia  
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    ' Delete any z-shift(s) co <ATx  
    count = 0 p^=>N9  
    While GetOperationCount(eID)>count .iDxq8l  
        GetOperation eID, count, op %D::$,;<<  
        If op.Type="ShiftZ" Then F4=+xd >0  
            DeleteOperation eID,count K2=`.  
            count=count-1 R`7v3{  
        End If )+
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        count=count+1 j_r?4k
 
    Wend vY+{zGF  
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    'Set new z-shift .I6:iB  
    op.Type = "ShiftZ" lu]Z2xSv  
    op.val1 = tlens )p,uZ`~
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    op.parent = parID ]e*Zx;6oi  
    AddOperation eID, op H|E{n/g  
    Print "Set lens thickness = " & tlens
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    '************************************************************************* ||{V*"+\  
    'Lens index of refraction k>W5ts2+  
    '************************************************************************* |*~=w J_  
    eID = FindMaterial( "Lens" ) UKIDFDn6_  
    GetModelMaterial eID, mat t}Z*2=DO  
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    mat.Nd = nlens y:FxX8S$'e  
    SetModelMaterial eID, mat
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    Print "Set lens index of refraction = " & nlens mLa0BIP  
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    '************************************************************************* 5&
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    'Pupil diameter o6H\JCne  
    '************************************************************************* bzz{ p1e  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) V}leEf2'  
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    'Adjust pupil diameter (trimming volume inner hole) auV'`PR  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" C'iJFfgR  
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    ' Adjust pupil location to just in front of the lens "8pfLI  
    parID = FindFullName( "Geometry.Arizona Eye" ) *O`76+iZ|_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) o6@Hj+,,  
    count = 0 w(lxq:>"  
    While GetOperationCount(eID)>count c0lVt)pr/  
        GetOperation eID, count, op gk%8iT  
        If op.Type="ShiftZ" Then ?*I _'2  
            DeleteOperation eID,count ;$ot,mH?T  
            count=count-1 $VX<UK$|s  
        End If O2W EA  
        count=count+1 /eM_:H5  
    Wend %h"+J  
    op.Type = "ShiftZ" IIN"'7Z^R  
    op.val1 = taq-0.01 #MZ0Sd8]&  
    op.parent = parID _g%Wx?K9  
    AddOperation eID, op 9!XW):  
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    Print "Set pupil diameter = " & pupilDiam QlbhQkn  
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    'Update AZ Eye subassembly Description =~Ac=j!q  
    eID = FindFullName( "Geometry.Arizona Eye" ) ^1&xt(G  
    GetEntity eID, entity ;l]OmcL  
    entity.Description = "Accommodation = " & A & "D" bL=32YS  
    SetEntity eID, entity (7P{k<5  
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    Update 9]Q\Pr\Ub$  
    Print "DONE!" .O\z:GrSZz  
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End Sub 4<`x*8` ,  
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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： gE,i
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Accommodation = 4 Diopters B_u+$Odo  
Pupil Diameter = 4 mm 8T5s6EmIOW  
Set aqueous humor thickness = 2.81 b"Hg4i)  
Set anterior lens radius = 10.4 and conic constant = -2.375869 NN<kO#c+2  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 i8$tId  
Set lens thickness = 3.927 F,CQAgx  
Set lens index of refraction = 1.42672 3r=IO#  
Set pupil diameter = 4 O,Xf.O1c  
DONE! M5C}*c9  
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