[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 L@X
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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。 JiCDY)bu  
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模型 G ,An8GR%&  
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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。 w-pdpbHV  
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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. 9;NR   
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光源 TeSF  
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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。 MPhO#;v  
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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。 "z8L}IC!e5  
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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。 J.N%=-8  
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视网膜的散射 3@f@4t@5V  
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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。 #XE`8$  
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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。 +}@1X&v:  
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脚本 \#Ez["mD  
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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： Q&S\?cKe  
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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。 1A^~gYr  
余下的脚本计算与屈光度有关的所有参数。 _1S^A0ft  
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分析 L?T%;VdG'>  
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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。 *J&XM[t  
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脚本代码 \x\_I1|  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. PZmg7N  
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Dim entity As T_ENTITY T>,3V:X  
Dim op As T_OPERATION gx~79;6  
Dim mat As T_MODELMATERIAL [9| 8p$  
Dim A As Double $Kw)BnV  
Dim pupilDiam As Double :I*G tq   
Dim eID As Long `&]<_Jc1  
Dim parID As Long QhUv(]
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Dim count As Integer x@/ N9*  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q[+&n*  
Dim tlens As Double, nlens As Double DA;,)A&=Q  
Dim curv As Double, conic As Double t ' _Au8  
Dim ok As Long ~7a(KJgvd"  
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Sub Main S3EM6`q'  
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    '用户输入对话框 G Xx7/X  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 %6rMS}  
        TextBox 220,21,40,21,.TextBox1 'default: 0 IO3`/R-  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 FaS}$-0  
        OKButton 40,91,90,21 [
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        CancelButton 190,91,90,21 v%N/mL+5L  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 `D)ay  
        TextBox 220,49,40,21,.TextBox2 'default: 4 itV
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    End Dialog CZaUrr  
    Dim dlg As UserDialog rS1mBrqD  
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    ok = Dialog (dlg) 5MUM{(C  
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    If ok=0 Then    'cancel button was pressed d67Q@')00  
        Print "Execution cancelled." k+Ew+j1_  
        End
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    End If mHc
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    'Assign accommodation and pupil diameter & use defaults if field left empty FgA'X<  
    If dlg.TextBox1 = "" Then uLFnuK  
        A = 0           'Default accommodation wV\;,(<x=%  
    Else 1HOYp*{#wP  
        A = CDbl(dlg.TextBox1) +|6 '7Z(9  
    End If lFvRXV^+f  
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    If dlg.TextBox2 = "" Then fT)u`voE,  
        pupilDiam = 4   'Default pupil diameter ACQbw)tiv}  
    Else ND);7  
        pupilDiam = CDbl(dlg.TextBox2) i"|="O0v5  
    End If |KSd@  
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    Print " " Ut"~I)S{LT  
    Print "Accommodation = " & A & " Diopters" $r0~&$T&  
    Print "Pupil Diameter = " & pupilDiam & " mm" "XQj~L  
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    ' Calculate new parameters with accommodation rzmd`)g  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 7+^9"k7  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 7kDX_,i  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Qn`$xY9mT  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens b'i-/l$  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ml &Cr  
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    tlens = 3.767 + 0.04*A                  'Lens thickness BGAqg=nDV  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction qf7:Q?+.|  
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    'Adjust parameters to account for accommodation l+# l\q%l  
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    '************************************************************************* ~pM\]OC  
    'Aqueous thickness (Position of Lens) FFE IsB"9  
    '************************************************************************* -9Iz$(>a  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ziFg+i%
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    GetCustomElement eID, entity N^,@s"g  
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    parID = FindFullName( "Geometry.Arizona Eye" ) a%3V< "f  
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    ' Delete any shift(s) in z &{#4^.Q  
    count = 0 4=]CAO=O  
    While GetOperationCount(eID)>count 6k?,'&z|~  
        GetOperation eID, count, op PbR6>'  
        If op.Type="ShiftZ" Then zk)9tm;i{  
            DeleteOperation eID,count Vs>/q
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            count=count-1 Ie3 F  
        End If pz'l9Gp;@  
        count=count+1 $i# 1<Qj  
    Wend jVh I`F{n  
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    'Set new shift in 1.+w&Y5   
    op.Type = "ShiftZ" iTb k]$  
    op.val1 = taq
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    op.parent = parID S<RJ46  
    AddOperation eID, op IfyyA  
    Print "Set aqueous humor thickness = " & taq-0.55 YyI4T/0s_  
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    '************************************************************************* 6.]x@=Wm  
    'Radius and conic constant of anterior lens XhF7%KR  
    '************************************************************************* I]S8:w![  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Q/e$Ttt4J  
    GetConic eID, entity, curv, conic 7|~j=,HU+Z  
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    SetConic eID, entity, 1/Rant, CCant ~N</;{}fL4  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant )ESF)aKMiz  
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    '************************************************************************* m%8idjnG  
    'Radius and conic constant of posterior lens h/9{E:ML  
    '************************************************************************* W'2a1E  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) *0y|0J+0  
    GetConic eID, entity, curv, conic @S3G>i  
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    SetConic eID, entity, 1/Rpost, CCpost d1=kHU4_9  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost m@K5eh  
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    '************************************************************************* +-=o16*{ !  
    'Lens thickness (Position of posterior lens surface) idL6*%M  
    '************************************************************************* [K2\e N~g  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) }m6zu'CV  
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    ' Delete any z-shift(s) 5w:   
    count = 0 oH/6  
    While GetOperationCount(eID)>count +8+@Az[e0  
        GetOperation eID, count, op 7%aaqQ1T  
        If op.Type="ShiftZ" Then sP1wO4M?{  
            DeleteOperation eID,count [<~1.L^I  
            count=count-1 d ]LF5*i  
        End If
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        count=count+1 R(dVE\u  
    Wend FU-YI"  
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    'Set new z-shift u!in>]^  
    op.Type = "ShiftZ" oObm5e*Z  
    op.val1 = tlens y#\jc4F_a  
    op.parent = parID ]<z4p'F1%  
    AddOperation eID, op /I2RU2|B  
    Print "Set lens thickness = " & tlens Vmj7`w&  
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    '************************************************************************* = ;sEi:HC  
    'Lens index of refraction :Mz$~o<  
    '************************************************************************* #BQ7rF7CNE  
    eID = FindMaterial( "Lens" ) hQ!slO  
    GetModelMaterial eID, mat y~)rZ-eSB  
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    mat.Nd = nlens hX#s3)87  
    SetModelMaterial eID, mat ,fS}cpV  
    Print "Set lens index of refraction = " & nlens iV
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    '************************************************************************* FYIzMp.4  
    'Pupil diameter +QcgLq  
    '************************************************************************* u|m>h(O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 5m,{?M`  
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    'Adjust pupil diameter (trimming volume inner hole) Y40Hcc+Fx  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ZA
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    ' Adjust pupil location to just in front of the lens G_EU/p<Q  
    parID = FindFullName( "Geometry.Arizona Eye" ) d4c-(ZRl  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) &IGTCTBP  
    count = 0 1 h(oty2p  
    While GetOperationCount(eID)>count $YvT* T$_  
        GetOperation eID, count, op eto3dJ!R  
        If op.Type="ShiftZ" Then TK.a6HJG  
            DeleteOperation eID,count J{$+\  
            count=count-1 X+;
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        End If nenYP0  
        count=count+1 b#h?O}  
    Wend Q+/:5Z C  
    op.Type = "ShiftZ" %)
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    op.val1 = taq-0.01 QF/A-[V
 
    op.parent = parID h4CDZ  
    AddOperation eID, op 2XJn3wPi  
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    Print "Set pupil diameter = " & pupilDiam c)8V^7
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    'Update AZ Eye subassembly Description EL+6u>\-k  
    eID = FindFullName( "Geometry.Arizona Eye" ) loVUB'OSv  
    GetEntity eID, entity MCH
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    entity.Description = "Accommodation = " & A & "D" 1aKYxjYM  
    SetEntity eID, entity 910Ym!\{:  
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    Update hQ&S*f&='  
    Print "DONE!" LjUBV_J  
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End Sub ?29zcuRaru  
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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： o)'u%m  
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Accommodation = 4 Diopters 65bLkR{0  
Pupil Diameter = 4 mm !xoN%5!  
Set aqueous humor thickness = 2.81 Ws?BAfP  
Set anterior lens radius = 10.4 and conic constant = -2.375869 e*_8B2da  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 lyiBRMiP|  
Set lens thickness = 3.927 $Gb] K{e  
Set lens index of refraction = 1.42672 g|*2O}<  
Set pupil diameter = 4 c^P8)gPf  
DONE! ^.Cfa  
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