[技术]Arizona眼睛模型 [复制链接]

简介 YQ; cJ$  
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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。 :4|M jn  
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模型 m+?N7  
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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。 C\7u<2c  
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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. N#4N?BBP"  
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光源 `ruNA>M  
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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。 t-WjL@$F/  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 k'Gw!p}  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 B@ {&<  
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视网膜的散射 eJHp6)2  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 >.e+S?o  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ,X68xk.'  
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脚本 F)SPaC4  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： je%ldY]/@  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 'H|~u&?  
余下的脚本计算与屈光度有关的所有参数。 w^HjZV  
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分析 [ ny6W9  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 M&KyA  
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脚本代码 8md*wEjk  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. +&5'uAe  
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Dim entity As T_ENTITY bcH_V|5
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Dim op As T_OPERATION ^:KO_{3E  
Dim mat As T_MODELMATERIAL I[d]!YI}F  
Dim A As Double X
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Dim pupilDiam As Double DMn4ll|  
Dim eID As Long  &;c>O  
Dim parID As Long 7 ^$;  
Dim count As Integer TTZe$>f  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double QR0(,e$Dl  
Dim tlens As Double, nlens As Double XRtD< jlA"  
Dim curv As Double, conic As Double qf#)lyr<D6  
Dim ok As Long ]*N1t>
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Sub Main lG:kAtx4  
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    '用户输入对话框 -SCM:j%h  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 S,{tV=&m]  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Am"(+>W21  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 S,jZ3^  
        OKButton 40,91,90,21 n V&cC  
        CancelButton 190,91,90,21 t;NV $!!  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ny*i+4Mb  
        TextBox 220,49,40,21,.TextBox2 'default: 4 vScjq5"p  
    End Dialog F<|t\KOW  
    Dim dlg As UserDialog 5,)vJ,fs  
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    ok = Dialog (dlg) k N7Bd}  
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    If ok=0 Then    'cancel button was pressed h6:#!Rg  
        Print "Execution cancelled." *ZrSiIPP  
        End uLR<FpM  
    End If B?bW1  
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    'Assign accommodation and pupil diameter & use defaults if field left empty g>J
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    If dlg.TextBox1 = "" Then 78 f$6J q  
        A = 0           'Default accommodation -NJ!g/ >mM  
    Else 9+=gke  
        A = CDbl(dlg.TextBox1) bulS&dAX  
    End If i3$$,W!  
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    If dlg.TextBox2 = "" Then W?woNt'n  
        pupilDiam = 4   'Default pupil diameter XvTCK>1  
    Else Z4b||  
        pupilDiam = CDbl(dlg.TextBox2) }H> ^o9  
    End If [iP#VM-N  
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    Print " " 64>krmVIe  
    Print "Accommodation = " & A & " Diopters" ]=pR  
    Print "Pupil Diameter = " & pupilDiam & " mm" X}ma]  
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    ' Calculate new parameters with accommodation ]6r;}1c  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ]`g@UtD9`  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 6w8">~)Z  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens MGS-4>Q#  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ZBT1Y.qA  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Zdc63fllM  
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    tlens = 3.767 + 0.04*A                  'Lens thickness m0n)dje  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Z<[<n0o1  
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    'Adjust parameters to account for accommodation @mP]*$00  
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    '************************************************************************* O/s$SX%g  
    'Aqueous thickness (Position of Lens) :}8Z@H!KkY  
    '************************************************************************* afBE{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) IYn]U4P.  
    GetCustomElement eID, entity \MC-4Yz  
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    parID = FindFullName( "Geometry.Arizona Eye" ) R0ID2:i]F  
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    ' Delete any shift(s) in z !* Ti}oIo&  
    count = 0 zi R5:d3   
    While GetOperationCount(eID)>count M>9-=$7  
        GetOperation eID, count, op o1W:ox?kO  
        If op.Type="ShiftZ" Then R'EUV0KX>Y  
            DeleteOperation eID,count %,Sf1fUJ
 
            count=count-1 U$]|~41#  
        End If 00v&lQBW  
        count=count+1 Vtc36-\1*  
    Wend ?Nf>]|K:Q  
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    'Set new shift in !tfb*@{;'  
    op.Type = "ShiftZ" 0"2=n.##  
    op.val1 = taq {~!q`Dr3?q  
    op.parent = parID F<>!kK/c  
    AddOperation eID, op r.3/
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    Print "Set aqueous humor thickness = " & taq-0.55 S5~VD?O,  
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    '************************************************************************* Gj"7s8(/K|  
    'Radius and conic constant of anterior lens (?_S6HE  
    '************************************************************************* ];.pK  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &j(+/;A  
    GetConic eID, entity, curv, conic Ox#\M0Wn$3  
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    SetConic eID, entity, 1/Rant, CCant _^Mx>hb4.  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant *Qugv^-  
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    '*************************************************************************
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    'Radius and conic constant of posterior lens ,'[<bP'%_  
    '************************************************************************* (WJ${OW  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )
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    GetConic eID, entity, curv, conic TIp:FW[  
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    SetConic eID, entity, 1/Rpost, CCpost 'cY`
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost n6s}ww)  
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    '************************************************************************* XsnF~)YW  
    'Lens thickness (Position of posterior lens surface) ,%\o4Rc'o  
    '************************************************************************* fS~;>n%R  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /~x"wo  
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    ' Delete any z-shift(s) 5:'hj$~|\1  
    count = 0 R|wGU)KEc'  
    While GetOperationCount(eID)>count K|dso]b/  
        GetOperation eID, count, op 0eK*9S]  
        If op.Type="ShiftZ" Then %Gt.m  
            DeleteOperation eID,count z5)s/;Sc  
            count=count-1 v|U(+O  
        End If (SKVuR%Jj  
        count=count+1 os/vtyP:a  
    Wend 0
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    'Set new z-shift T49zcJf;  
    op.Type = "ShiftZ" zN  [2YJ$  
    op.val1 = tlens 6/rFHY2q  
    op.parent = parID cJ54s}  
    AddOperation eID, op lP<:tR~K  
    Print "Set lens thickness = " & tlens NH+(?TN  
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    '************************************************************************* *zr(Zv  
    'Lens index of refraction N^3N[l
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    '************************************************************************* !?|Th5e  
    eID = FindMaterial( "Lens" ) {mAU3x  
    GetModelMaterial eID, mat o7|eMe?<t  
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    mat.Nd = nlens qi_Jywd:w  
    SetModelMaterial eID, mat OF\rgz
 
    Print "Set lens index of refraction = " & nlens I'|$}/\`  
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    '************************************************************************* U"
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    'Pupil diameter vd8{c7g:n  
    '************************************************************************* )E~79!  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) L'F<ev  
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    'Adjust pupil diameter (trimming volume inner hole) u9N 1pZ~  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" b,CaWg  
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    ' Adjust pupil location to just in front of the lens J>\B`E  
    parID = FindFullName( "Geometry.Arizona Eye" ) ub|V\M{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) f"<O0Qw  
    count = 0 ~$~5qwl  
    While GetOperationCount(eID)>count B'fb^n<  
        GetOperation eID, count, op K"r*M.P>  
        If op.Type="ShiftZ" Then kXf'5p1  
            DeleteOperation eID,count a[ex[TRKe  
            count=count-1 gSh+}r<7  
        End If d+'p@!W_  
        count=count+1 0zi~p>*nJC  
    Wend l(02W  
    op.Type = "ShiftZ" +(h\fm7*-  
    op.val1 = taq-0.01 5F~'gLH/F-  
    op.parent = parID 7x@A%2J  
    AddOperation eID, op Bro9YP4<  
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    Print "Set pupil diameter = " & pupilDiam 62Z#YQ}x  
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    'Update AZ Eye subassembly Description R=|{n'n$0|  
    eID = FindFullName( "Geometry.Arizona Eye" ) sD=n95`v  
    GetEntity eID, entity $g sxO!G  
    entity.Description = "Accommodation = " & A & "D" 8|" XSN  
    SetEntity eID, entity :3I@(k\PY  
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    Update O<,\^[x  
    Print "DONE!" \ioH\9  
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End Sub Pqn@ST  
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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： &sU?Ok6  
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Accommodation = 4 Diopters #Jw1IcuH
 
Pupil Diameter = 4 mm =W"F[fD  
Set aqueous humor thickness = 2.81 pim!.=vN/U  
Set anterior lens radius = 10.4 and conic constant = -2.375869 2n
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 i{`;R  
Set lens thickness = 3.927 /\hzb/  
Set lens index of refraction = 1.42672 D8xmE2%  
Set pupil diameter = 4 6E^.7%3  
DONE! D/Mi^5H)