[技术]Arizona眼睛模型 [复制链接]

简介 #:E^($v  
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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。 Q;k D Jo  
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模型 7?]wAH89  
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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。 tpQ
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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. IN=l|Q$8f  
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光源 :a*F>S!  
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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。 50^CILKo7  
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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。 l'RuzBQr  
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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。 v M $Tn  
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视网膜的散射 q)!G5j3  
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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。 keS%w]87  
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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。 %iD'2e:  
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脚本 puK /;nns  
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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： | (: PX  
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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。 2KQpmNN  
余下的脚本计算与屈光度有关的所有参数。 _j?/O)M c  
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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-Wphc!m  
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脚本代码 $qk(yzY  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. J}s)#va9R  
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Dim entity As T_ENTITY uDG#L6  
Dim op As T_OPERATION YojYb]y+j  
Dim mat As T_MODELMATERIAL QW6\~l 4  
Dim A As Double 
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Dim pupilDiam As Double y0cB@pWp  
Dim eID As Long e]u3[ao  
Dim parID As Long P*6&0\af|  
Dim count As Integer \bumB<w(]  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double
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Dim tlens As Double, nlens As Double ]z5gC`E0  
Dim curv As Double, conic As Double {9YNv<3  
Dim ok As Long 5:~BGK&{Y  
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Sub Main y3pr(w9A  
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    '用户输入对话框 F<N
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 3NC-)S   
        TextBox 220,21,40,21,.TextBox1 'default: 0 "ju0S&  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 yf7$m_$C'  
        OKButton 40,91,90,21 ;c;PNihg  
        CancelButton 190,91,90,21 U#1,]a\  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 f iu?mb=*  
        TextBox 220,49,40,21,.TextBox2 'default: 4 $.-\2;U  
    End Dialog psZ #^@>mJ  
    Dim dlg As UserDialog i;8tA!  
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    ok = Dialog (dlg) Irnfr\l.  
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    If ok=0 Then    'cancel button was pressed :Vx5%4J  
        Print "Execution cancelled." 7!-y72qx  
        End RNn5,W  
    End If [_?dpaTt  
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    'Assign accommodation and pupil diameter & use defaults if field left empty '{xPdN  
    If dlg.TextBox1 = "" Then nnPY8pdjSD  
        A = 0           'Default accommodation Ff@Cs0R  
    Else a'2^kds  
        A = CDbl(dlg.TextBox1) sZ9VXnz24  
    End If QL_9a,R'r  
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    If dlg.TextBox2 = "" Then x)Ls(Xh+g  
        pupilDiam = 4   'Default pupil diameter {@w!kl~8  
    Else m'P,:S)=  
        pupilDiam = CDbl(dlg.TextBox2) I,d5Y3mC  
    End If  dr iw\  
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    Print " " ~i y]X:U  
    Print "Accommodation = " & A & " Diopters" X,"(G}KUA  
    Print "Pupil Diameter = " & pupilDiam & " mm" :gJ?3LwTf  
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    ' Calculate new parameters with accommodation -r!sY+Z>  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness bI"_hvcFp  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens >l3iAy!sZ  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens nVt,= ?_ U  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens n6Qsug$z  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens lEe<!B$d"  
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    tlens = 3.767 + 0.04*A                  'Lens thickness qu:nV"~_  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction p\ }Ep  
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    'Adjust parameters to account for accommodation *P.Dbb8vn  
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    '************************************************************************* .!pr0/9B  
    'Aqueous thickness (Position of Lens) $|V@3`0  
    '************************************************************************* kED1s's  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) shAoib?Kw:  
    GetCustomElement eID, entity TppuEC>  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ~DYv6-p%  
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    ' Delete any shift(s) in z lEWF~L5=:  
    count = 0 EkvTl-  
    While GetOperationCount(eID)>count +xc1cki_{  
        GetOperation eID, count, op 2`;&Uwt  
        If op.Type="ShiftZ" Then i=^!? i  
            DeleteOperation eID,count Fb0r(vQ^  
            count=count-1 y9xvGr[l  
        End If 0mMoDJRy  
        count=count+1 4ru-qF  
    Wend R#^.8g)t  
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    'Set new shift in qG<3H!Z!ky  
    op.Type = "ShiftZ" 7B)m/%>3s  
    op.val1 = taq 'C2X9/!,  
    op.parent = parID <lo\7p$A  
    AddOperation eID, op
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    Print "Set aqueous humor thickness = " & taq-0.55 :[r/ Y  
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    '************************************************************************* EIrAq!CA  
    'Radius and conic constant of anterior lens D02(6|  
    '************************************************************************* _*m<Z;Et  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) nUy.gAb  
    GetConic eID, entity, curv, conic N7 FndB5%  
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    SetConic eID, entity, 1/Rant, CCant js..k
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant =G,wR'M  
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    '************************************************************************* 9>6DA^
 
    'Radius and conic constant of posterior lens u$38"&cmA  
    '************************************************************************* )p^" J|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) x=M%QFe  
    GetConic eID, entity, curv, conic X;&
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    SetConic eID, entity, 1/Rpost, CCpost =f/CBYNw@V  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 2t[P-on  
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    '************************************************************************* QHDR*tB:{  
    'Lens thickness (Position of posterior lens surface) !y\r.fm!A  
    '************************************************************************* !7hjA=0  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'w z6Zt  
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    ' Delete any z-shift(s) B%^W$7 q  
    count = 0 %;eD.If}  
    While GetOperationCount(eID)>count omMOA  
        GetOperation eID, count, op 'CMbqLk#  
        If op.Type="ShiftZ" Then , UsY0YC  
            DeleteOperation eID,count 4=~+Bz  
            count=count-1 dM=45$\q  
        End If :;hz!6!  
        count=count+1 F1)5"7f  
    Wend AxtmG\o>  
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    'Set new z-shift bEKhU\@=J  
    op.Type = "ShiftZ" @xXVJWEU:  
    op.val1 = tlens @9tzk [  
    op.parent = parID ![i)_XO  
    AddOperation eID, op {sfA$ d0  
    Print "Set lens thickness = " & tlens *\(MG|S  
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    '************************************************************************* SF=TG84<  
    'Lens index of refraction GoLK 95"]  
    '************************************************************************* FS)"MDs  
    eID = FindMaterial( "Lens" ) I`f5)iF?0  
    GetModelMaterial eID, mat ]t0St~qUL)  
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    mat.Nd = nlens n_4 r'w  
    SetModelMaterial eID, mat kV+%(Gl8  
    Print "Set lens index of refraction = " & nlens 1Q/=s,{u  
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    '************************************************************************* Vw|P;LLl`  
    'Pupil diameter rQxiG[0  
    '************************************************************************* 'u:
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) PjD9D.  
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    'Adjust pupil diameter (trimming volume inner hole) `*l aUn  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ", p5}}/  
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    ' Adjust pupil location to just in front of the lens <2E|URo,#  
    parID = FindFullName( "Geometry.Arizona Eye" ) FUarI5#fwF  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) B[I9<4}  
    count = 0 )n]"~I^  
    While GetOperationCount(eID)>count >%ovL8F  
        GetOperation eID, count, op Cz)&R^  
        If op.Type="ShiftZ" Then v\[+  
            DeleteOperation eID,count 1<Sg@  
            count=count-1 &7i&"TNptP  
        End If Z5E; FGPb  
        count=count+1 8t3m$<7  
    Wend |AH>EXhv  
    op.Type = "ShiftZ" RG*Vdom  
    op.val1 = taq-0.01 n)~*B
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    op.parent = parID f S[-K?K  
    AddOperation eID, op a'-u(Bw  
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    Print "Set pupil diameter = " & pupilDiam m):*>o55  
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    'Update AZ Eye subassembly Description ~o>Gm>5!HH  
    eID = FindFullName( "Geometry.Arizona Eye" ) /)T~(o|i  
    GetEntity eID, entity XZ . T%g  
    entity.Description = "Accommodation = " & A & "D" lxm/*^  
    SetEntity eID, entity _1NK9dp:  
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    Update mU]VFPr5  
    Print "DONE!" i!zFW-*5  
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End Sub {fnx=BaG  
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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： |mP};&b  
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Accommodation = 4 Diopters <|3%}?  
Pupil Diameter = 4 mm \"1>NJn&k)  
Set aqueous humor thickness = 2.81 <n4`#d  
Set anterior lens radius = 10.4 and conic constant = -2.375869 xZP*%yM  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 l2LLM
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Set lens thickness = 3.927 r=&,2meo  
Set lens index of refraction = 1.42672 'w27Lt'V  
Set pupil diameter = 4 :{
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DONE! IH;sVT$M