[技术]Arizona眼睛模型 [复制链接]

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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。 LGPg\g`  
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模型 xoNn
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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。 #4ii!ev  
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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. S")*~)N@  
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光源 JbW!V
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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。 sr`)l&t?  
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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。 z|sR `
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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。 fg~9{1B
 
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视网膜的散射 M;1B}x@  
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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。 If%**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。 Xsv^GmP+  
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脚本 F)4;:".zna  
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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： - u'
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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。 Gt5'-Hyo  
余下的脚本计算与屈光度有关的所有参数。 ICXz(?a  
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分析 p/.[cH  
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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。 {B+{2;Zk  
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脚本代码 WbDD9ZS  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ;mLbgiqQ J  
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Dim entity As T_ENTITY {1]/ok2k5  
Dim op As T_OPERATION C4/p5J  
Dim mat As T_MODELMATERIAL %<Te&6NU
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Dim A As Double u!K5jqP  
Dim pupilDiam As Double l/o 4bkV  
Dim eID As Long e-/+e64Q@  
Dim parID As Long 3rQ;}<*M  
Dim count As Integer @$%[D`Wa<  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ECEDNib  
Dim tlens As Double, nlens As Double =pR'XF%  
Dim curv As Double, conic As Double p:q?8+W-r  
Dim ok As Long U
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Sub Main lVc':,z  
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    '用户输入对话框 H@!kgaNF
 
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Wo8.tu-2  
        TextBox 220,21,40,21,.TextBox1 'default: 0 NgPY/R>  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 @&LtIN#  
        OKButton 40,91,90,21 A%
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        CancelButton 190,91,90,21 FW7@7cVoF  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 *^b<CZd9  
        TextBox 220,49,40,21,.TextBox2 'default: 4 wUBug  
    End Dialog zM*PN|/%sH  
    Dim dlg As UserDialog { WW!P,w  
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    ok = Dialog (dlg) *{e?%!Q  
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    If ok=0 Then    'cancel button was pressed o?\v 8.n  
        Print "Execution cancelled." )/2J|LxS  
        End Af%#&r7W  
    End If nt*nTtcE  
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    'Assign accommodation and pupil diameter & use defaults if field left empty m?#J`?E  
    If dlg.TextBox1 = "" Then :ncR7:Z  
        A = 0           'Default accommodation jVhfpS[  
    Else ;'g.%  
        A = CDbl(dlg.TextBox1) {s/u[T_D2  
    End If `lA[-x~  
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    If dlg.TextBox2 = "" Then iS%md  
        pupilDiam = 4   'Default pupil diameter ^~:&/0  
    Else 1}"PLq(  
        pupilDiam = CDbl(dlg.TextBox2) pJpTOq\h  
    End If W n43TSs-  
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    Print " " `zZGL&9m`  
    Print "Accommodation = " & A & " Diopters" 6EeK5XLf,  
    Print "Pupil Diameter = " & pupilDiam & " mm" ij/5m-{6)  
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    ' Calculate new parameters with accommodation ]fgYO+  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness -w#Hy>E  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens hd E?%A  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens '7Aj0U(  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens e//q`?
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens MH8Selnv  
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    tlens = 3.767 + 0.04*A                  'Lens thickness b=-LQkcZhK  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction hz8Z)xjJ V  
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    'Adjust parameters to account for accommodation oA1d8*i^E  
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    '************************************************************************* DKGZm<G>  
    'Aqueous thickness (Position of Lens) 7<ZCeM2x  
    '************************************************************************* $sX X6K),  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 6+;B2;*3  
    GetCustomElement eID, entity Ao/KB_4f*Q  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Gap\~Z@L  
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    ' Delete any shift(s) in z i[wEH1jR  
    count = 0 /EpsJb`kj  
    While GetOperationCount(eID)>count u3>Dvl@  
        GetOperation eID, count, op [x.DwU%S  
        If op.Type="ShiftZ" Then x$
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            DeleteOperation eID,count gqi|k6V/  
            count=count-1 \?X'U:  
        End If ,Q5Z<\  
        count=count+1 D`G ;kp  
    Wend cI Byv I-  
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    'Set new shift in IO4 8sV }  
    op.Type = "ShiftZ" ct3^V M&/  
    op.val1 = taq zU7/P|Dw+  
    op.parent = parID N){/#3  
    AddOperation eID, op sP+Z
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    Print "Set aqueous humor thickness = " & taq-0.55 3;h%mkKQ+  
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    '************************************************************************* q["T6  
    'Radius and conic constant of anterior lens e
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    '************************************************************************* {{\ d5CkX  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) y,`SLgBID  
    GetConic eID, entity, curv, conic EZ.|6oug\  
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    SetConic eID, entity, 1/Rant, CCant {J}Zv5  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant u{-J?t&`  
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    '************************************************************************* ?5>Ep:{+/  
    'Radius and conic constant of posterior lens {'QA0K  
    '************************************************************************* U6pG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 1gZW~6a}  
    GetConic eID, entity, curv, conic m'Thm{Y,?n  
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    SetConic eID, entity, 1/Rpost, CCpost O'G
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost $g?`yE(K  
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    '************************************************************************* Zu$30&U  
    'Lens thickness (Position of posterior lens surface)
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    '************************************************************************* Q0}Sju+HX  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 2[Ja|W\If  
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    ' Delete any z-shift(s) %e@Jc3  
    count = 0 sKkk+-J4  
    While GetOperationCount(eID)>count W+'|zhn  
        GetOperation eID, count, op /kAu&}  
        If op.Type="ShiftZ" Then 3+%c*}KC~  
            DeleteOperation eID,count .!\NM&E  
            count=count-1 jM E==)Y  
        End If <]u~;e57  
        count=count+1 ]Y%?kQ^  
    Wend <oE(I)r4,  
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    'Set new z-shift O%(E 6 n  
    op.Type = "ShiftZ" Wa8?o~0"L  
    op.val1 = tlens O=HT3gp&  
    op.parent = parID }538vFNi  
    AddOperation eID, op ;n9r;$!f  
    Print "Set lens thickness = " & tlens QzwA*\G  
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    '************************************************************************* ?E@9Nvr  
    'Lens index of refraction 7,sslf2%K  
    '************************************************************************* L
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    eID = FindMaterial( "Lens" ) >lo,0oG  
    GetModelMaterial eID, mat kT!Y~c  
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    mat.Nd = nlens #8!xIy  
    SetModelMaterial eID, mat -N')LY  
    Print "Set lens index of refraction = " & nlens mgB7l0)b  
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    '************************************************************************* v.08,P
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    'Pupil diameter _$+lyea   
    '************************************************************************* u |hT1l  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) xp395ub6  
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    'Adjust pupil diameter (trimming volume inner hole) l3sL!D1u  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" \X=?+| 9  
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    ' Adjust pupil location to just in front of the lens xwwy9:ze*l  
    parID = FindFullName( "Geometry.Arizona Eye" ) +v 9@du  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) yW&|ZJF?  
    count = 0 nyZUf{:  
    While GetOperationCount(eID)>count 26YY1T\B)  
        GetOperation eID, count, op %|l^oC+E  
        If op.Type="ShiftZ" Then / M(A kNy  
            DeleteOperation eID,count <c[+60p"  
            count=count-1 AwhXCq|k  
        End If ,cR=W|6cQm  
        count=count+1 MCOz-8@|Y  
    Wend I/ pv0  
    op.Type = "ShiftZ" 3[Rb
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    op.val1 = taq-0.01 %)7HBj(*J  
    op.parent = parID ;:nO5VFOg  
    AddOperation eID, op N798("  

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    Print "Set pupil diameter = " & pupilDiam N7=L^]  
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    'Update AZ Eye subassembly Description 2=3pV!)4}  
    eID = FindFullName( "Geometry.Arizona Eye" ) Fm@G@W7,m  
    GetEntity eID, entity {L[n\h.4.  
    entity.Description = "Accommodation = " & A & "D" qM(n]{H  
    SetEntity eID, entity 2Uf}gG)  
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    Update #>m#i1Nu  
    Print "DONE!" i-(^t1c  
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End Sub #C+""qm  
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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： . Q3GA0O  
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Accommodation = 4 Diopters 6{rH|Z  
Pupil Diameter = 4 mm 7/.-dfEK  
Set aqueous humor thickness = 2.81 9kcp(  
Set anterior lens radius = 10.4 and conic constant = -2.375869 zG_e=  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 t_@xzt10y  
Set lens thickness = 3.927 >gAq/'.Q  
Set lens index of refraction = 1.42672 Sb=cWn P  
Set pupil diameter = 4 J1I"H<}-6  
DONE! .6Sw
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