[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 )9B:Y;>)  
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。 +Juh:1H  
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模型 H'Nq#K  
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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。 o,1Dqg4P3  
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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. n}JPYu  
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光源 zW5C1:.3K  
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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。 vQgq]mA?  
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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。 $Asr`Q1i   
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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。 :b@igZ<  
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视网膜的散射 6e.[,-eU  
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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。 yQ%"U^.m  
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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。 Da_()e[9p  
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脚本 "VTF}#Uo  
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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： E oe}l   
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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。 n_23EcSy  
余下的脚本计算与屈光度有关的所有参数。 >;9NtoE  
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分析 0BK5qz  
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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。 i=#F)AD^5#  
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脚本代码 Fe!9y2Mg  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used.  uMd. j$$  
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Dim entity As T_ENTITY O|'1B>X  
Dim op As T_OPERATION >
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Dim mat As T_MODELMATERIAL 6R4<J%$P  
Dim A As Double !
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Dim pupilDiam As Double k\aK?(.RC7  
Dim eID As Long +@:L|uFU  
Dim parID As Long uM
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Dim count As Integer #ekM"p  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6N
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Dim tlens As Double, nlens As Double eR;!(Oy=A  
Dim curv As Double, conic As Double '*T]fND4  
Dim ok As Long @dEiVF`4:  
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Sub Main 4XJiIa?  
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    '用户输入对话框 T?wzwGp-[  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ar^i|`D  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Vw~\H Gs/~  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 {y-^~Q"z  
        OKButton 40,91,90,21 g0&\l}&%U  
        CancelButton 190,91,90,21 ]Kh2;>= Xj  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ,hRN\Kt)p  
        TextBox 220,49,40,21,.TextBox2 'default: 4 [TTSA2  
    End Dialog <<zI\+V  
    Dim dlg As UserDialog ;rHO
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    ok = Dialog (dlg) 'i|rjW(  
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    If ok=0 Then    'cancel button was pressed ]A+o>#n}x  
        Print "Execution cancelled." ELD!{bMT  
        End |i7a@'0)  
    End If eJ@~o{,?>  
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    'Assign accommodation and pupil diameter & use defaults if field left empty h~}.G{"  
    If dlg.TextBox1 = "" Then #&8rcu;/  
        A = 0           'Default accommodation {/8
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    Else z`3( ,V  
        A = CDbl(dlg.TextBox1) I;MD>%[W,  
    End If egR-w[{  
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    If dlg.TextBox2 = "" Then )"<8K}%!  
        pupilDiam = 4   'Default pupil diameter B80aw>M  
    Else 0C$vS`s&  
        pupilDiam = CDbl(dlg.TextBox2) ~)]} 91p  
    End If ~r*P]*51x  
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    Print " " -:Rp'SJ  
    Print "Accommodation = " & A & " Diopters" #JW+~FU`  
    Print "Pupil Diameter = " & pupilDiam & " mm" +j/~Af p5f  
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    ' Calculate new parameters with accommodation 1KE:[YQ1  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness qUJ aeQ  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens gAbD7SE  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |oFAGP1  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens $j
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens R9o-`Wz  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ``K#}3  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction YwDt.6(+,  
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    'Adjust parameters to account for accommodation k;^ :  
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    '************************************************************************* n# 7Pr/*0  
    'Aqueous thickness (Position of Lens) &, a3@i  
    '************************************************************************* N"7]R[*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >{zk qvsQ&  
    GetCustomElement eID, entity bn9;7`>.  
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    parID = FindFullName( "Geometry.Arizona Eye" ) /bRg?Q  
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    ' Delete any shift(s) in z PL=^}{r  
    count = 0 6<'K~1do:  
    While GetOperationCount(eID)>count ]ZoPQUS?  
        GetOperation eID, count, op =r.
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        If op.Type="ShiftZ" Then OjE`1h\  
            DeleteOperation eID,count _=XX~^I,  
            count=count-1 QO;4}rq  
        End If `)$_YZq|SR  
        count=count+1 G;iEo4\?  
    Wend _.)eL3OF  
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    'Set new shift in ))h6~1`  
    op.Type = "ShiftZ"  ZI>km?w  
    op.val1 = taq N@T.T=r  
    op.parent = parID k ]a*&me  
    AddOperation eID, op kAYb!h[`  
    Print "Set aqueous humor thickness = " & taq-0.55 )X+mV  
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    '************************************************************************* SI:ifR&T  
    'Radius and conic constant of anterior lens e&<yX  
    '************************************************************************* .p` pG3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )
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    GetConic eID, entity, curv, conic W&Y"K)`  
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    SetConic eID, entity, 1/Rant, CCant V&{MQWy  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant E>jh"|f:{  
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    '************************************************************************* PXKJ^fa  
    'Radius and conic constant of posterior lens YPDf Y<?v  
    '************************************************************************* Av J4\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) r),PtI0X  
    GetConic eID, entity, curv, conic }ut]\]b  
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    SetConic eID, entity, 1/Rpost, CCpost iPG0o %  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost YNdrW
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    '************************************************************************* $rB3m~c|  
    'Lens thickness (Position of posterior lens surface) 9=l.T/?sf  
    '************************************************************************* A;XOT6jv?  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1%[_`J;>Z  
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    ' Delete any z-shift(s) I,@r5tKo  
    count = 0 4<,|*hAT  
    While GetOperationCount(eID)>count E$s/]wnr[  
        GetOperation eID, count, op KxGX\   
        If op.Type="ShiftZ" Then vT^Sk;E  
            DeleteOperation eID,count Z3KO90O!8  
            count=count-1 ,U,By~s  
        End If (46 {r}_O  
        count=count+1 b,H[I!. %  
    Wend K+\nC)oG  
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    'Set new z-shift +\ _{x/u1  
    op.Type = "ShiftZ" !v|ISyK  
    op.val1 = tlens 5v.DX`"  
    op.parent = parID bp<^R  
    AddOperation eID, op |`k .y]9  
    Print "Set lens thickness = " & tlens 66&EBX}  
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    '************************************************************************* gApoX0nrv  
    'Lens index of refraction +ZsX*/TOn  
    '************************************************************************* Y qdWctUY  
    eID = FindMaterial( "Lens" ) F4#g?R::U  
    GetModelMaterial eID, mat 6SM:x]`##,  
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    mat.Nd = nlens R@Y=o].2  
    SetModelMaterial eID, mat _cH@I?B  
    Print "Set lens index of refraction = " & nlens [onqNp  
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    '************************************************************************* D0G-5}s`  
    'Pupil diameter AnsjmR:Jv  
    '************************************************************************* Fqq6^um  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) \0;(VLN'U  
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    'Adjust pupil diameter (trimming volume inner hole) &[R8Q|1j  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" hn)a@  
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    ' Adjust pupil location to just in front of the lens K/_9f'^  
    parID = FindFullName( "Geometry.Arizona Eye" ) 'm=*u SJK  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ~,6b_W p/  
    count = 0 u0)7i.!M  
    While GetOperationCount(eID)>count fIC9WbiH-  
        GetOperation eID, count, op -4#2/GXNO  
        If op.Type="ShiftZ" Then EOKzzX7 S  
            DeleteOperation eID,count 5`[n8mU  
            count=count-1 5~ 'Ie<Y_  
        End If /?-7Fg+,  
        count=count+1 we7c`1E  
    Wend 0[A9b,MMVO  
    op.Type = "ShiftZ" 9W`Frx'h1  
    op.val1 = taq-0.01 O09ke-lC  
    op.parent = parID Y
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    AddOperation eID, op aT  l c  
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    Print "Set pupil diameter = " & pupilDiam L#[]I,  
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    'Update AZ Eye subassembly Description (n{wg(R  
    eID = FindFullName( "Geometry.Arizona Eye" ) [`=LTBt  
    GetEntity eID, entity `\|ssC8u  
    entity.Description = "Accommodation = " & A & "D" )u ?' ;  
    SetEntity eID, entity &:B<Q$g#  
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    Update {NM+Oj,~'  
    Print "DONE!" f3*?MXxb16  
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End Sub =4!nFi  
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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： E .6HpIx  
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Accommodation = 4 Diopters ,hxkk`  
Pupil Diameter = 4 mm HG>j5  
Set aqueous humor thickness = 2.81 u~zs* qp  
Set anterior lens radius = 10.4 and conic constant = -2.375869 !|?e7u7  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 L];y}]:F*  
Set lens thickness = 3.927 W{cY
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Set lens index of refraction = 1.42672 *v%rMU7,  
Set pupil diameter = 4 M.}7pJ7f  
DONE! 0"k|H&  
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