[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 E^.y$d~dS  
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。 IT,TSs/Y  
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模型 4:\s.Z{!3  
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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。 [sC]<2
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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. "_qH+=_R  
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光源 z6)SaSYE  
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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。 G:FP9  
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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。 0]l _qxv  
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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。 AL/q6PWi  
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视网膜的散射 &pS <4  
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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。 ylF%6!V}4V  
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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。 ^[}^+  
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脚本 x^kV;^ I  
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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： `}gjfu -'\  
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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。 n7`R+4/s  
余下的脚本计算与屈光度有关的所有参数。 K!6k<  
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分析 S[rz=[7{  
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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。 K1M
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脚本代码 1.YDIB||  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. '#REbY5ev  
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Dim entity As T_ENTITY [(U:1&x&  
Dim op As T_OPERATION k3::5&  
Dim mat As T_MODELMATERIAL VSa\X~  
Dim A As Double Heatt?(RR  
Dim pupilDiam As Double 7Z0
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Dim eID As Long H(U`
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Dim parID As Long eO#Kn'5  
Dim count As Integer e[f}Lxln  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double wP.b2X_V  
Dim tlens As Double, nlens As Double UN'[sHjOnD  
Dim curv As Double, conic As Double OnE#8*
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Dim ok As Long d 6 t#4!  
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Sub Main .6Tan2[%  
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    '用户输入对话框 %"|I` m  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Tg|0!0qD]F  
        TextBox 220,21,40,21,.TextBox1 'default: 0 -J8&!S8X  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 T:&  
        OKButton 40,91,90,21 hw/:  
        CancelButton 190,91,90,21 Mz,G;x}  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 4SRX@/ #8*  
        TextBox 220,49,40,21,.TextBox2 'default: 4 EYNi`  
    End Dialog k^B<t'  
    Dim dlg As UserDialog x"q!=&>f  
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    ok = Dialog (dlg) 9<BC6M_/  
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    If ok=0 Then    'cancel button was pressed xi|T7,\X  
        Print "Execution cancelled." 2fIHFo\8  
        End g{wOq{7V  
    End If yO\.dp  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Q!7il<S  
    If dlg.TextBox1 = "" Then gX
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        A = 0           'Default accommodation m{T:<:q~  
    Else J?VMQTa/+  
        A = CDbl(dlg.TextBox1) ?`ETlFtD4  
    End If [\eh$r\
 
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    If dlg.TextBox2 = "" Then L-Io!msb  
        pupilDiam = 4   'Default pupil diameter bzYj`t?  
    Else V0 70o
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        pupilDiam = CDbl(dlg.TextBox2) QP HibPP:  
    End If 8$)xxV_zp  
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    Print " " ?wM{NVt#-  
    Print "Accommodation = " & A & " Diopters" +/+:D9j ,  
    Print "Pupil Diameter = " & pupilDiam & " mm" Z!HQ|')N5  
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    ' Calculate new parameters with accommodation kucH=96  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ndW]S7  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 44@yQ?  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens :(7icHa  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens R^u 1(SF  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens L>xecep  
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    tlens = 3.767 + 0.04*A                  'Lens thickness >#pZ`oPEAv  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \PU7,*2  
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    'Adjust parameters to account for accommodation -d'swx2aZ!  
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    '************************************************************************* 2Kg-ZDK8  
    'Aqueous thickness (Position of Lens) s>pM+PoGYd  
    '************************************************************************* +"P!es\q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) vca]yK<u  
    GetCustomElement eID, entity ylTX  
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    parID = FindFullName( "Geometry.Arizona Eye" ) MgpjC`  
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    ' Delete any shift(s) in z <D}yqq@|  
    count = 0 fX:=_c   
    While GetOperationCount(eID)>count )h0
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        GetOperation eID, count, op I='6>+P  
        If op.Type="ShiftZ" Then *WzvPl$e  
            DeleteOperation eID,count /+ yIcE(&3  
            count=count-1 a+!r5689  
        End If C3k[ipCN  
        count=count+1 NC@L,)F  
    Wend :<QmG3F  
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    'Set new shift in 8u|F %Sg  
    op.Type = "ShiftZ" @1c[<3xJT  
    op.val1 = taq nNc>nB1  
    op.parent = parID Mp-hNO}.Z  
    AddOperation eID, op h85kQ^%  
    Print "Set aqueous humor thickness = " & taq-0.55 'lWgHmE  
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    '************************************************************************* +H**VdM6s  
    'Radius and conic constant of anterior lens b fj]Q  
    '************************************************************************* n[E/O}3& /  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) cqd}.D  
    GetConic eID, entity, curv, conic ~~iFs ,9  
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    SetConic eID, entity, 1/Rant, CCant 9]4W  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant T8t_+|( G  
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    '************************************************************************* bnzIDsw!Q  
    'Radius and conic constant of posterior lens A6S|pO1)3  
    '************************************************************************* EK8rV  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) wg}rMJoG|  
    GetConic eID, entity, curv, conic qGkD] L  
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    SetConic eID, entity, 1/Rpost, CCpost ; 8B)J<y  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost :jHDeF.A  
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    '************************************************************************* s2kom)  
    'Lens thickness (Position of posterior lens surface) lHI?GiB@  
    '************************************************************************* aGs\zCAP  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) E``\Jre@  
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    ' Delete any z-shift(s) L (@".{T  
    count = 0 X%R)  
    While GetOperationCount(eID)>count iF^   
        GetOperation eID, count, op 2t}^8  
        If op.Type="ShiftZ" Then _t-e.2a v  
            DeleteOperation eID,count d`sIgll&n  
            count=count-1 OhW o  
        End If M{)|9F  
        count=count+1 kP[LS1}*  
    Wend LXq0hI  
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    'Set new z-shift j21>\K!p  
    op.Type = "ShiftZ" p%#=OtkC  
    op.val1 = tlens Sau?Y  
    op.parent = parID /VHQ!Wi  
    AddOperation eID, op s$ZKd  
    Print "Set lens thickness = " & tlens ;y]BXW&l&  
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    '************************************************************************* J/>9
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    'Lens index of refraction 5J2tR6u-(  
    '************************************************************************* !V27ln KP+  
    eID = FindMaterial( "Lens" ) |_u|Td(n  
    GetModelMaterial eID, mat :Oh*Q(>  
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    mat.Nd = nlens A|<i7QVY  
    SetModelMaterial eID, mat a_(fqoW  
    Print "Set lens index of refraction = " & nlens YDjjhe+  
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    '************************************************************************* PL*1-t?#  
    'Pupil diameter U}c05GiQw  
    '************************************************************************* `7 3I}%?  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;.I,R NM  
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    'Adjust pupil diameter (trimming volume inner hole) <o: O<p@6  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" z+{Q(8'b]  
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    ' Adjust pupil location to just in front of the lens vC%Hc/&.}  
    parID = FindFullName( "Geometry.Arizona Eye" ) 9/dI 6P7  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) XLj|y#h  
    count = 0 PwS7!dzH-  
    While GetOperationCount(eID)>count qt=nN-AC(  
        GetOperation eID, count, op 2|JtRE+  
        If op.Type="ShiftZ" Then @,;VMO  
            DeleteOperation eID,count I`uOsZBO/  
            count=count-1 fDrjR6xV  
        End If v@Bk)Z  
        count=count+1 k{E!X  
    Wend Rd,5&X$  
    op.Type = "ShiftZ" R=<uf:ca  
    op.val1 = taq-0.01 qs3V2lvYw{  
    op.parent = parID f19'IH$n{  
    AddOperation eID, op 5K {{o''  
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    Print "Set pupil diameter = " & pupilDiam @% .;}tC  
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    'Update AZ Eye subassembly Description HC>MCwx=r  
    eID = FindFullName( "Geometry.Arizona Eye" ) ?vg|;Q  
    GetEntity eID, entity \!df)qdu  
    entity.Description = "Accommodation = " & A & "D" uU!}/mbo  
    SetEntity eID, entity =S<E[D{V`  
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    Update cjc1iciZ  
    Print "DONE!" qU+qY2S:  
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End Sub J9q[u[QZ9O  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： \PM5B"MDZ  
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Accommodation = 4 Diopters MxLi'R=  
Pupil Diameter = 4 mm r(p@{L185  
Set aqueous humor thickness = 2.81 yBnUz"  
Set anterior lens radius = 10.4 and conic constant = -2.375869 UsnIx54D3  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 RFT`r  
Set lens thickness = 3.927 ?7\$zn)v#  
Set lens index of refraction = 1.42672 e<duDW$X  
Set pupil diameter = 4 DNGj81'c  
DONE! ?xYoCn}Z  
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