[技术]Arizona眼睛模型 [复制链接]

简介 4}s'xMT!  
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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。 *V4%&&{  
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模型 <p}7T]a7  
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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。 fp*6Dv_  
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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. {*P[dyu  
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光源 e^oGiL~  
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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。 6VVxpDAi:  
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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。 FvY=!U06  
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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。 NyT%S?@y<  
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视网膜的散射 )z\#  
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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。 ')0@J`  
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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。 URs]S~tk  
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脚本 9TQVgkW  
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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： G;flj}z  
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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。 2|=hF9  
余下的脚本计算与屈光度有关的所有参数。 jLM([t  
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分析 u*): D~A  
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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。 qFwt^w  
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脚本代码 !u@P\8M}  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. hNsi 8/  
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Dim entity As T_ENTITY ij;NM:|Sd  
Dim op As T_OPERATION xYCJO(&  
Dim mat As T_MODELMATERIAL A5J41yH  
Dim A As Double S4`X^a}pY  
Dim pupilDiam As Double L7;~4_M9.V  
Dim eID As Long tp}/>gU!  
Dim parID As Long v:/\;2  
Dim count As Integer
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double RSh_~qMX  
Dim tlens As Double, nlens As Double 7)V"E-6h  
Dim curv As Double, conic As Double ~qj(&[U{c\  
Dim ok As Long Hp04apM:  
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Sub Main \.}T_,I  
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    '用户输入对话框 babL.Ua8o  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 %L*EB;nK  
        TextBox 220,21,40,21,.TextBox1 'default: 0 W/bW=.d Jd  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 {%G9iOV.  
        OKButton 40,91,90,21 Qgj# k  
        CancelButton 190,91,90,21 Ajm!;LA[jO  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 O&BvWik  
        TextBox 220,49,40,21,.TextBox2 'default: 4 '0+~]4&}q  
    End Dialog 0(wu  
    Dim dlg As UserDialog t&?{+?p: 9  
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    ok = Dialog (dlg) !i~(h&z  
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    If ok=0 Then    'cancel button was pressed wQUl!s7M;  
        Print "Execution cancelled." Zh;wQCDj  
        End <[)-Q~Gg5  
    End If ;&O?4?@4  
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    'Assign accommodation and pupil diameter & use defaults if field left empty &>,]YrU  
    If dlg.TextBox1 = "" Then up'`
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        A = 0           'Default accommodation 2$5"
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    Else d,Aa8I  
        A = CDbl(dlg.TextBox1) &|{1Ws  
    End If qisvGHo  
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    If dlg.TextBox2 = "" Then v#qdq!64  
        pupilDiam = 4   'Default pupil diameter 0fXMY-$I  
    Else |-}.Y(y  
        pupilDiam = CDbl(dlg.TextBox2) o13jd NQ-  
    End If >|A,rE^Ojt  
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    Print " " ~^' ,4<K-}  
    Print "Accommodation = " & A & " Diopters" dgpE3 37Lt  
    Print "Pupil Diameter = " & pupilDiam & " mm" 49Jnp>h  
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    ' Calculate new parameters with accommodation 6]b"n'G  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness XeI2<=@%  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens y<Q"]H.CkQ  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens H9(?yI@Zr#  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens \s&Mz;:  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens y
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    tlens = 3.767 + 0.04*A                  'Lens thickness a{T.U-0   
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction :E.a.-  
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    'Adjust parameters to account for accommodation (p%|F`  
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    '************************************************************************* gQ{ #C'  
    'Aqueous thickness (Position of Lens) .U0Gm_c0  
    '************************************************************************* p3U)J&]c6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) s
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    GetCustomElement eID, entity ?z9!=A%<V~  
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    parID = FindFullName( "Geometry.Arizona Eye" ) w.
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    ' Delete any shift(s) in z e%JIqKS  
    count = 0 }:IIk-JoC  
    While GetOperationCount(eID)>count NbU`_^oC  
        GetOperation eID, count, op cuQ!"iH  
        If op.Type="ShiftZ" Then U9:)qvMXe  
            DeleteOperation eID,count X 61|:E  
            count=count-1 n>ui'}L  
        End If GJ*IH9YR  
        count=count+1 7{F\b  
    Wend {Ge{@1  
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    'Set new shift in q~R8<G%YK  
    op.Type = "ShiftZ" ?@G s7'  
    op.val1 = taq Z0L($  
    op.parent = parID "@nH;Xlq  
    AddOperation eID, op X,v.1#[  
    Print "Set aqueous humor thickness = " & taq-0.55 YbP @  
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    '************************************************************************* ZW [&7[4  
    'Radius and conic constant of anterior lens =-si| 1Z  
    '************************************************************************* MQ!4"E5"j  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^L2d%d\5  
    GetConic eID, entity, curv, conic S1|u@d'  
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    SetConic eID, entity, 1/Rant, CCant 3}H{4]*%_  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant cz9J&Le>  
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    '************************************************************************* G]ek-[-  
    'Radius and conic constant of posterior lens A2 +%  
    '************************************************************************* U4!KO;Jc  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ?y-^Fq|h  
    GetConic eID, entity, curv, conic H d|p@$I  
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    SetConic eID, entity, 1/Rpost, CCpost |c/=9Bb  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost F$as#.7FF  
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    '************************************************************************* :|W=2(>  
    'Lens thickness (Position of posterior lens surface) nc;eNB  
    '************************************************************************* ,m#  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) t.9s49P  
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    ' Delete any z-shift(s) '.bf88D  
    count = 0 s:tX3X  
    While GetOperationCount(eID)>count wo0j/4o  
        GetOperation eID, count, op ,->K)Rs;  
        If op.Type="ShiftZ" Then R0RxcBtG  
            DeleteOperation eID,count 7%  D4  
            count=count-1 ^`kwSC  
        End If QR&e~rks  
        count=count+1 "UTW(~D'  
    Wend V5K/)\#  
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    'Set new z-shift RzqgN*]lY  
    op.Type = "ShiftZ" i3w
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    op.val1 = tlens 9
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    op.parent = parID v.(dOIrX  
    AddOperation eID, op %aNm j)L  
    Print "Set lens thickness = " & tlens eNd&
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    '************************************************************************* f'=u`*(b7  
    'Lens index of refraction R/oi6EKv  
    '************************************************************************* G(7%*@SX  
    eID = FindMaterial( "Lens" ) lbAhP+B  
    GetModelMaterial eID, mat Z^|N]Ej  
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    mat.Nd = nlens MZV$YD^S  
    SetModelMaterial eID, mat e\V -L_  
    Print "Set lens index of refraction = " & nlens KZ%i&w#<  
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    '************************************************************************* QCb
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    'Pupil diameter x-[ItJ% l  
    '************************************************************************* Y1h)aQ5{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  ;2C  
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    'Adjust pupil diameter (trimming volume inner hole) C7C4 eW8  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" M8~3 0L  
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    ' Adjust pupil location to just in front of the lens D./{f8
 
    parID = FindFullName( "Geometry.Arizona Eye" ) !5}}mf  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) "9_$7.q<y  
    count = 0 7FE36Ub9  
    While GetOperationCount(eID)>count i"<W6  
        GetOperation eID, count, op PuJ3#H T  
        If op.Type="ShiftZ" Then -$:;en?  
            DeleteOperation eID,count tczJ
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            count=count-1 <[[yV  
        End If VO0:4{-  
        count=count+1 2fTuIS<yr  
    Wend q}Q G<%VR  
    op.Type = "ShiftZ" $9X+dvu*  
    op.val1 = taq-0.01 GTR*3,rw  
    op.parent = parID (p5q MP]L  
    AddOperation eID, op r!&174DSR1  
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    Print "Set pupil diameter = " & pupilDiam >Hnm.?-AWl  
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    'Update AZ Eye subassembly Description 4:/V
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    eID = FindFullName( "Geometry.Arizona Eye" ) jC'h54,Mr  
    GetEntity eID, entity un 5r9  
    entity.Description = "Accommodation = " & A & "D" hP)Zm%@0f  
    SetEntity eID, entity 5REFz  
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    Update DC h !Z{I  
    Print "DONE!" \#,2#BmO"E  
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End Sub #KiJ{w'  
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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： ?"Ez  
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Accommodation = 4 Diopters 1%v6d !  
Pupil Diameter = 4 mm
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Set aqueous humor thickness = 2.81 qKD  
Set anterior lens radius = 10.4 and conic constant = -2.375869 or*{P=m+R  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 jc"sPrv5  
Set lens thickness = 3.927 66&uK|  
Set lens index of refraction = 1.42672 2jyWkAP'  
Set pupil diameter = 4 J
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DONE! )c4tGT<