[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 myR}~Cj;q  
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。 q1|! oQ  
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模型 NoR=:Q 9e  
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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。 l$>))cW!  
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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. B9Ha6kj  
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光源 $bGe1\  
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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。 6v]y\+  
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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。 Sh]g]xR  
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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。 ,{pC1A@s  
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视网膜的散射 !,I530eh7  
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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。 :epjJ1mW  
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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。 Me.t_)  
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脚本 f<Co&^A  
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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 T3wJQ5N  
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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。 s--
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余下的脚本计算与屈光度有关的所有参数。 Gp PlO]  
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分析 2&k5X-Y  
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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。 w|;kL{(W  
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脚本代码 R24ZjbKL  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. >`@c9 m  
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Dim entity As T_ENTITY VgoN=S  
Dim op As T_OPERATION 6z(eW]p  
Dim mat As T_MODELMATERIAL 3=SN;cn  
Dim A As Double ,%L>TD'48s  
Dim pupilDiam As Double ,z*-93H1  
Dim eID As Long z]d^%>Ef  
Dim parID As Long @`hnp:  
Dim count As Integer `2j \(N,  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double X5M{No>z  
Dim tlens As Double, nlens As Double ?;//%c8,.  
Dim curv As Double, conic As Double @t;WdbxB%  
Dim ok As Long w(y#{!%+  
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Sub Main N~w4|q!]  
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    '用户输入对话框 d+6 by,'  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 U;QN+fF]u  
        TextBox 220,21,40,21,.TextBox1 'default: 0 x+L G4++  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |&>!"27;w  
        OKButton 40,91,90,21 z_jTR[dY  
        CancelButton 190,91,90,21 ][b2Q>  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 pxF<L\L?:  
        TextBox 220,49,40,21,.TextBox2 'default: 4 iTt#%Fs)4M  
    End Dialog nt"8kv  
    Dim dlg As UserDialog jv"^_1  
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    ok = Dialog (dlg) ]/_GHG9  
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    If ok=0 Then    'cancel button was pressed L 1fK  
        Print "Execution cancelled." q0}
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        End &|:T+LVv$+  
    End If s 4Mi9h_  
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    'Assign accommodation and pupil diameter & use defaults if field left empty K-xmLEu  
    If dlg.TextBox1 = "" Then aWLeyXsAu  
        A = 0           'Default accommodation f>u{e~Q,  
    Else =uYz4IDB  
        A = CDbl(dlg.TextBox1) "/EE$eU  
    End If a-`OE"  
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    If dlg.TextBox2 = "" Then Ozygr?*X  
        pupilDiam = 4   'Default pupil diameter 4E Hb  
    Else .?TPoqs7Z  
        pupilDiam = CDbl(dlg.TextBox2) Kp|#04]  
    End If I)
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    Print " " Z
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    Print "Accommodation = " & A & " Diopters" ?|i6]y=D  
    Print "Pupil Diameter = " & pupilDiam & " mm" n&. bs7N2  
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    ' Calculate new parameters with accommodation [n`SXBi+n  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 5 i1T?  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens )8c`o  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 6zQ {Y"0  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens !lSxBr[dQ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens /S]W<8d  
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    tlens = 3.767 + 0.04*A                  'Lens thickness C +-<  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ?kICYtY:_b  
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    'Adjust parameters to account for accommodation (8!#<$  
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    '************************************************************************* ~3{C&c  
    'Aqueous thickness (Position of Lens) I#Q Tmg.  
    '************************************************************************* /`iBv8!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) mx#H+:}&r  
    GetCustomElement eID, entity ,w.`(?I/  
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    parID = FindFullName( "Geometry.Arizona Eye" ) jafq(t  
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    ' Delete any shift(s) in z 8gap _qTo  
    count = 0 S7Xr~5>X  
    While GetOperationCount(eID)>count r<;bArs-u  
        GetOperation eID, count, op IJ^KYho  
        If op.Type="ShiftZ" Then @<]xbWhuw  
            DeleteOperation eID,count v
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            count=count-1 &bx;GG\<4  
        End If >G2o  
        count=count+1 G"jKYW  
    Wend ^4LkKYMS  
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    'Set new shift in H_'i.t 'SS  
    op.Type = "ShiftZ" ~U:{~z  
    op.val1 = taq :&=TE2  
    op.parent = parID ]1 #&J(  
    AddOperation eID, op d"nz/$  
    Print "Set aqueous humor thickness = " & taq-0.55 b#-5b%ON  
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    '************************************************************************* QD LXfl/  
    'Radius and conic constant of anterior lens 5_+vjV;5  
    '************************************************************************* /&=E=S6
 
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )  Z*d8b  
    GetConic eID, entity, curv, conic ,\;;1Kq  
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    SetConic eID, entity, 1/Rant, CCant n4%|F'ma  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant f
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    '************************************************************************* bz_Zk  
    'Radius and conic constant of posterior lens d"+zDc;  
    '************************************************************************* eI?<*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) *b?C%a9  
    GetConic eID, entity, curv, conic :Ia3yi#  
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    SetConic eID, entity, 1/Rpost, CCpost (Q !4\Gy  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;YxQo o>  
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    '************************************************************************* ^RG6h  
    'Lens thickness (Position of posterior lens surface) 0SV#M6`GX  
    '************************************************************************* :g3n
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'v4#mf  
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    ' Delete any z-shift(s) R2Fh WiL  
    count = 0 wJJ4F$"b  
    While GetOperationCount(eID)>count Vg/{;uLAe  
        GetOperation eID, count, op w[z^B&  
        If op.Type="ShiftZ" Then hGcq>Cvf  
            DeleteOperation eID,count a +Q9kh  
            count=count-1 y3$i?}?A  
        End If d$s1l  
        count=count+1 4VPL -":6  
    Wend @L^2VVWk^  
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    'Set new z-shift Y((s<]7  
    op.Type = "ShiftZ" cj-P&D[Ny[  
    op.val1 = tlens |@={:gRJ{x  
    op.parent = parID go/]+vD  
    AddOperation eID, op Rd;k>e  
    Print "Set lens thickness = " & tlens DF'-dh</*  
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    '************************************************************************* Lm\N`  
    'Lens index of refraction o:_}=1nh  
    '************************************************************************* `pzp(\lc  
    eID = FindMaterial( "Lens" ) aQwcPy|1R  
    GetModelMaterial eID, mat _n_lO8mK  
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    mat.Nd = nlens  ~%_$e/T  
    SetModelMaterial eID, mat 6 k+FTDL  
    Print "Set lens index of refraction = " & nlens zJ7vAL
  
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    '************************************************************************* =6imrRaaV  
    'Pupil diameter CQ2{5  
    '************************************************************************* 4)+MvKxjS  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) B;[{7J]  
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    'Adjust pupil diameter (trimming volume inner hole) O5{!CT$  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 7+JQaYO`"  
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    ' Adjust pupil location to just in front of the lens _)Q)tOW  
    parID = FindFullName( "Geometry.Arizona Eye" ) O^|dc=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 2hAu~#X  
    count = 0 QIF|pZ+^  
    While GetOperationCount(eID)>count ,K .P,z~*  
        GetOperation eID, count, op E"bYl3  
        If op.Type="ShiftZ" Then db^S@}  
            DeleteOperation eID,count vb)
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            count=count-1 k_#ra7zP  
        End If :U)q(.53  
        count=count+1 n;Tpf<*U  
    Wend ^kxkP}[Z.  
    op.Type = "ShiftZ" 7}>j
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    op.val1 = taq-0.01 esx<feP)\  
    op.parent = parID +4f>njARIb  
    AddOperation eID, op z:bxnM2\  
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    Print "Set pupil diameter = " & pupilDiam
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    'Update AZ Eye subassembly Description aB"W6[  
    eID = FindFullName( "Geometry.Arizona Eye" ) LGKkT?fcSC  
    GetEntity eID, entity X|t?{.p  
    entity.Description = "Accommodation = " & A & "D" e~=fo#*2?@  
    SetEntity eID, entity G+ PBV%gE[  
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    Update ~F^=7oq  
    Print "DONE!" -}@3,G  
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End Sub [>::@[  
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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： pa Uh+"y>  
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Accommodation = 4 Diopters kM|ak
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Pupil Diameter = 4 mm pbKDtqSnz  
Set aqueous humor thickness = 2.81 T!eeMsI
 
Set anterior lens radius = 10.4 and conic constant = -2.375869 rc1EJ(c  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 0*YLFqN  
Set lens thickness = 3.927 YUJlQ2e(  
Set lens index of refraction = 1.42672 QgO@oV*S  
Set pupil diameter = 4 (p26TN;*$5  
DONE! V;mKJ.d${  
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