[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 7|Wst)_~j  
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。 N1y,~Z  
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模型 ey<z#Q5+  
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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。 75
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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. 4Rp[>}L  
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光源 XH!n{Of  
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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。 N7 _
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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。 +WR'\15u  
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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。 Z
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视网膜的散射 hf)RPG&  
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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。 'wBOnGi6  
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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。 //$^~}wt  
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脚本 L&5zr_  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： {pRa%DF  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 S@,x^/vT  
余下的脚本计算与屈光度有关的所有参数。 tg%Sn+:  
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分析 xTZJ5iZ17  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 IMy!8$\u  
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脚本代码 0V2~  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. yS#D$q2_  
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Dim entity As T_ENTITY f[OJqk  
Dim op As T_OPERATION dr"@2=Z  
Dim mat As T_MODELMATERIAL rO,n~|YJ  
Dim A As Double aMgg[g9>t  
Dim pupilDiam As Double =NRiro  
Dim eID As Long fL&e^Q  
Dim parID As Long RHt~:D3*  
Dim count As Integer lqoVfj'6M  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 0+rBGk  
Dim tlens As Double, nlens As Double 1eS@ihkP  
Dim curv As Double, conic As Double HN&]`cr;  
Dim ok As Long t..@69  
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Sub Main ab_EH}j1\q  
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    '用户输入对话框 0gKSjTq
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 BQ!_i*14+  
        TextBox 220,21,40,21,.TextBox1 'default: 0 <$nMqUu0  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 H]0(GLvH  
        OKButton 40,91,90,21 yMb.~A^$J  
        CancelButton 190,91,90,21 ':T"nORC  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Hg[AulNna  
        TextBox 220,49,40,21,.TextBox2 'default: 4 sQ82(N7l  
    End Dialog dM5N1$1,  
    Dim dlg As UserDialog ?,!C0ts  
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    ok = Dialog (dlg) m8v=pab e  
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    If ok=0 Then    'cancel button was pressed kx[h41|n  
        Print "Execution cancelled." wOl]N2<  
        End 1ZfhDtK(  
    End If Z&y9m@  
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    'Assign accommodation and pupil diameter & use defaults if field left empty "Ze<dB#,Y  
    If dlg.TextBox1 = "" Then Ktf lbI!  
        A = 0           'Default accommodation )G$0:-J-  
    Else ?OWJUmQ  
        A = CDbl(dlg.TextBox1) x):h|/B  
    End If }{)>aJ  
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    If dlg.TextBox2 = "" Then ;e^`r;]  
        pupilDiam = 4   'Default pupil diameter VQ`a-DL  
    Else nx`I9j\  
        pupilDiam = CDbl(dlg.TextBox2) )}R w@70L-  
    End If :]IYw!_-p  
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    Print " " ?(j:F2dU~  
    Print "Accommodation = " & A & " Diopters" -$kAWP8P4  
    Print "Pupil Diameter = " & pupilDiam & " mm" %3$EV}dp  
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    ' Calculate new parameters with accommodation {o.i\"x;  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ;PX>] r5U0  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens =(>pv,  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ]kyGm2Ty9  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens R9lb<`  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens *`wgqin  
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    tlens = 3.767 + 0.04*A                  'Lens thickness i;}mIsNBY  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction i6D66E  
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    'Adjust parameters to account for accommodation :/'oh]T|  
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    '************************************************************************* "94qBGf  
    'Aqueous thickness (Position of Lens) MFm2p?zPm  
    '************************************************************************* $y+Bril5W  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 924a1
 
    GetCustomElement eID, entity 5\eM3w'd  
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    parID = FindFullName( "Geometry.Arizona Eye" ) VRa>bS  
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    ' Delete any shift(s) in z .=<
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    count = 0 'Q F@@48  
    While GetOperationCount(eID)>count u~q6?*5  
        GetOperation eID, count, op z1 P=P%F  
        If op.Type="ShiftZ" Then L9":=  
            DeleteOperation eID,count {pyTiz#JY  
            count=count-1 ae|j#!~oi  
        End If ._
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        count=count+1 r:Rk!z*  
    Wend ~zT743  
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    'Set new shift in ]:r6
 
    op.Type = "ShiftZ" ?."YP[;  
    op.val1 = taq #J09Eka;J  
    op.parent = parID w_]`)$
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    AddOperation eID, op eT6T@C
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    Print "Set aqueous humor thickness = " & taq-0.55  c 1o8  
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    '************************************************************************* s'Wu \r'  
    'Radius and conic constant of anterior lens %d"d<pvx  
    '************************************************************************* 3r-oZ8/n  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) o-_H+p6a  
    GetConic eID, entity, curv, conic k~=_]sLn  
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    SetConic eID, entity, 1/Rant, CCant dNfME*"yN  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant K#!c<
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    '************************************************************************* /@QPJ~%8Ud  
    'Radius and conic constant of posterior lens ni
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    '************************************************************************* %29lDd(<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) N>Q~WXvV#  
    GetConic eID, entity, curv, conic Uon^z?0A  
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    SetConic eID, entity, 1/Rpost, CCpost GZWU=TC2{2  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ee\QK,QV  
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    '************************************************************************* Q.Xs%{B  
    'Lens thickness (Position of posterior lens surface) j9^V)\6)  
    '************************************************************************* %"CF-K@th  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) <<l1zEf@  
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    ' Delete any z-shift(s)
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    count = 0 `b?o%5V2x  
    While GetOperationCount(eID)>count d.Ep#4  
        GetOperation eID, count, op !\Vc#dslt  
        If op.Type="ShiftZ" Then _`.Wib+  
            DeleteOperation eID,count 5DxNHEuS  
            count=count-1 7*\CfqrU  
        End If It:,8  
        count=count+1 )/cf%  
    Wend IF'Tj`yD  
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    'Set new z-shift |e{ ^Yf4  
    op.Type = "ShiftZ" 0"J0JcFX  
    op.val1 = tlens K;j0
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    op.parent = parID n4InZ!)
 
    AddOperation eID, op tg6iHFa  
    Print "Set lens thickness = " & tlens {L/hhKT  
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    '************************************************************************* )0?u_Z]w9  
    'Lens index of refraction Tnoy#w}Ve  
    '************************************************************************* .oH)eD  
    eID = FindMaterial( "Lens" ) <N{Y*,^z  
    GetModelMaterial eID, mat ,s`4k?y  
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    mat.Nd = nlens -BcnJK0  
    SetModelMaterial eID, mat )m_q2xV  
    Print "Set lens index of refraction = " & nlens = P$Q;d  
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    '************************************************************************* +$$5Cv5#<&  
    'Pupil diameter +vt?3i\^.  
    '************************************************************************* N$N7aE$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 9";qR,  
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    'Adjust pupil diameter (trimming volume inner hole) oy\U\#k   
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" H5Bh?mw2  
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    ' Adjust pupil location to just in front of the lens %l[]n;
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    parID = FindFullName( "Geometry.Arizona Eye" ) :!yPR  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ~JHEr48  
    count = 0 bT15jN
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    While GetOperationCount(eID)>count >|aVGY  
        GetOperation eID, count, op 0+T:};]  
        If op.Type="ShiftZ" Then |[!7^tU*  
            DeleteOperation eID,count MU:q`DRr  
            count=count-1 '*D>/hn|:]  
        End If N\anjG  
        count=count+1 2Mu@P8O&  
    Wend 'x6rU"e$J  
    op.Type = "ShiftZ" qSt\ 6~  
    op.val1 = taq-0.01 M|fC2[]v B  
    op.parent = parID jo' V.]\  
    AddOperation eID, op W`uq,r0Xsy  
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    Print "Set pupil diameter = " & pupilDiam MM6PaD{  
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    'Update AZ Eye subassembly Description u#UtPF7q  
    eID = FindFullName( "Geometry.Arizona Eye" ) wZVLpF+7  
    GetEntity eID, entity L7[f-cK2:  
    entity.Description = "Accommodation = " & A & "D" De2$:?  
    SetEntity eID, entity ,P%i%YPj  
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    Update WO6R04+WV  
    Print "DONE!" Qb|@DMq%  
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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： 6^lix9q7  
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Accommodation = 4 Diopters a7!{`fR5  
Pupil Diameter = 4 mm i*r ag0Mw  
Set aqueous humor thickness = 2.81 B(f_~]  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ]=PkgOJD  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 tUt_Q;%yC  
Set lens thickness = 3.927 ^1yD&i'q  
Set lens index of refraction = 1.42672 l6zYiM  
Set pupil diameter = 4 J9MAnYd)i  
DONE! a"`>J!  
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