[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 b'H'QY   
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。 N%y i4  
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模型 Ykbg5Z  
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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。 4`IM[DIG~  
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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.  `zwz  
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光源 OG,P"sv  
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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。 S2~cAhR|M  
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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。 THA9OXP  
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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。 Q=\ Oa(I  
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视网膜的散射 &c`-/8c  
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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。 "q4tvcK.  
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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。 G4&s_M$
 
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脚本 *
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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： k_=SDm a  
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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。 MatXhP] Fi  
余下的脚本计算与屈光度有关的所有参数。 )fH Q7  
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分析 0r]n 0?x  
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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。 sE9FT#iE  
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脚本代码 X/]@EF  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used.
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Dim entity As T_ENTITY KuNLu31%  
Dim op As T_OPERATION LyUn!zV$(  
Dim mat As T_MODELMATERIAL myx/|-V"F  
Dim A As Double q:{#kv8  
Dim pupilDiam As Double 1CtUf7 `/Q  
Dim eID As Long aCQtE,.  
Dim parID As Long }E`Y.= S  
Dim count As Integer 95;{ms[  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }v(wjD  
Dim tlens As Double, nlens As Double tobE3Od4  
Dim curv As Double, conic As Double ia6 jiW x  
Dim ok As Long Y~~Dg?e  
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Sub Main 6K2e]r  
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    '用户输入对话框 
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 k(Yz
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        TextBox 220,21,40,21,.TextBox1 'default: 0 uL'f8Pqg  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |5@Ra@0  
        OKButton 40,91,90,21 h!"2Ux3!x  
        CancelButton 190,91,90,21 F<4rn  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 I-v} DuM  
        TextBox 220,49,40,21,.TextBox2 'default: 4  ` Xc7b  
    End Dialog :XKYfc_y  
    Dim dlg As UserDialog 5f0M{J,KC  
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    ok = Dialog (dlg) +a#&W}K  
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    If ok=0 Then    'cancel button was pressed C|{Sj`,XG  
        Print "Execution cancelled." Y#U.9>h  
        End Q G)s  
    End If uLms0r\@!  
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    'Assign accommodation and pupil diameter & use defaults if field left empty dQX-s=XJ  
    If dlg.TextBox1 = "" Then ^[ae )}  
        A = 0           'Default accommodation ktu?-?#0,  
    Else dg D-"-O  
        A = CDbl(dlg.TextBox1) Sn:>|y~  
    End If ;W|kc</R*  
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    If dlg.TextBox2 = "" Then w,~*ead  
        pupilDiam = 4   'Default pupil diameter ,f03TBD}  
    Else o'Bd. B  
        pupilDiam = CDbl(dlg.TextBox2) /"m s  
    End If ZlV
 
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    Print " " SA,~q&  
    Print "Accommodation = " & A & " Diopters" '2,~'Zk  
    Print "Pupil Diameter = " & pupilDiam & " mm" /4{W
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    ' Calculate new parameters with accommodation g 2Fg  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness So5/n7  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens j
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens z:'m50'  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens a%go[_w  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens j/v>,MM  
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    tlens = 3.767 + 0.04*A                  'Lens thickness pEB3qGA  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &oL"AJU  
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    'Adjust parameters to account for accommodation qxRsq&_  
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    '************************************************************************* +|?a7qM  
    'Aqueous thickness (Position of Lens) L03I:IJ  
    '************************************************************************* `&;#A*C
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) q NGR6i  
    GetCustomElement eID, entity hB?#b`i^  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Owp]>e  
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    ' Delete any shift(s) in z +Q&l}2  
    count = 0 A-x^JC=  
    While GetOperationCount(eID)>count at>_EiS  
        GetOperation eID, count, op UG v
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        If op.Type="ShiftZ" Then r*HSi.'21  
            DeleteOperation eID,count ueg%yvO
 
            count=count-1 =i~ = |K!  
        End If &H_/`Z]Q  
        count=count+1 o HK  
    Wend DLwlA!z  
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    'Set new shift in F"Dr(V  
    op.Type = "ShiftZ" I!zoo[/)%  
    op.val1 = taq +;,{`*W+N  
    op.parent = parID 74_?@Z(  
    AddOperation eID, op -=-^rQx9  
    Print "Set aqueous humor thickness = " & taq-0.55 <h(AJX7wsD  
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    '************************************************************************* Ehy(;n)\  
    'Radius and conic constant of anterior lens yf{\^^ i(  
    '************************************************************************* U=v>gNba  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) (4Db%Iw  
    GetConic eID, entity, curv, conic ;v8TT}R  
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    SetConic eID, entity, 1/Rant, CCant M:O*_>KF  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant i7RK*{  
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    '************************************************************************* fMwF|;  
    'Radius and conic constant of posterior lens pIIp61=$  
    '************************************************************************* AB $N`+&
 
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) f y|JE9Io_  
    GetConic eID, entity, curv, conic U/c+j{=~  
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    SetConic eID, entity, 1/Rpost, CCpost X&Oo[Z  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %>&~?zrq  
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    '************************************************************************* ErN[maix#  
    'Lens thickness (Position of posterior lens surface)
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    '************************************************************************* dC<%D'L*  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) +s}!+I8P  
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    ' Delete any z-shift(s) *wAX&+);  
    count = 0 +sJ{9#6  
    While GetOperationCount(eID)>count tE>FL  
        GetOperation eID, count, op ^uo,LTq+  
        If op.Type="ShiftZ" Then %2RXrH2&H  
            DeleteOperation eID,count .0nT*LF  
            count=count-1 N+V#=Uy  
        End If ?23J(;)s  
        count=count+1 DN9x<
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    Wend d%@0xsU1  
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    'Set new z-shift W}F~vx.  
    op.Type = "ShiftZ" [6@bsXiw  
    op.val1 = tlens T7YJC,^m  
    op.parent = parID 6oKlr,.  
    AddOperation eID, op .KYs5Qu  
    Print "Set lens thickness = " & tlens lBn<\Y!^  
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    '*************************************************************************
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    'Lens index of refraction oe6Ex5h  
    '************************************************************************* w2$ L;q  
    eID = FindMaterial( "Lens" ) 4PC'7V=S  
    GetModelMaterial eID, mat )YCH>Za  
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    mat.Nd = nlens zt((TD2  
    SetModelMaterial eID, mat C&q}&=3r  
    Print "Set lens index of refraction = " & nlens
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    '************************************************************************* ;[zZI~wh  
    'Pupil diameter 6 y"r'  
    '************************************************************************* E.'6p \  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) yyPj!<.MGP  
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    'Adjust pupil diameter (trimming volume inner hole) mGz'%?zj  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 7F~Jz*,B*W  
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    ' Adjust pupil location to just in front of the lens yokZ>+jb  
    parID = FindFullName( "Geometry.Arizona Eye" ) a"+/fC`  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) w6 Y+Y;,'f  
    count = 0 fk#Ggp<  
    While GetOperationCount(eID)>count 11$v~<M  
        GetOperation eID, count, op xZAg  
        If op.Type="ShiftZ" Then a$"Z\F:x  
            DeleteOperation eID,count J_ h\tM  
            count=count-1 ?#5)TAW  
        End If $ z+ =lF  
        count=count+1 cP21x<n  
    Wend r|jBKq~  
    op.Type = "ShiftZ" ;r;>4+zn\  
    op.val1 = taq-0.01 Yk4ah$}%-^  
    op.parent = parID RXPl~]k#i  
    AddOperation eID, op rI:]''PR  
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    Print "Set pupil diameter = " & pupilDiam (ds*$]  
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    'Update AZ Eye subassembly Description 7")&njQ/x  
    eID = FindFullName( "Geometry.Arizona Eye" ) i;)r|L`V?  
    GetEntity eID, entity UR`pZ.U?  
    entity.Description = "Accommodation = " & A & "D" oRn5blj  
    SetEntity eID, entity 5OFb9YX  
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    Update .|ZnU]~T  
    Print "DONE!" ,"5p=JX`  
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End Sub =2wy;@f  
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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： z:$TW{%M  
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Accommodation = 4 Diopters nYY'hjZ  
Pupil Diameter = 4 mm 3TD!3p8
  
Set aqueous humor thickness = 2.81 :n?}G0y  
Set anterior lens radius = 10.4 and conic constant = -2.375869 '$OLU[(
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 _`94CC:  
Set lens thickness = 3.927 E}w<-]8  
Set lens index of refraction = 1.42672 ?@_,_gTQ  
Set pupil diameter = 4 )&elr,b/y  
DONE! [TpW$E0H  
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