[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 &6ZD136  
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。 FaDjLo2'o  
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模型 dep=&  
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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。 Qo;
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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. l'/R&`-n  
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光源 {>DEsO  
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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。
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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。 -* WXMzr  
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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。 @?yX!_YC  
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视网膜的散射 DU5c=rxW  
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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。 IC1NKn<k  
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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。 9Iwe2lu  
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脚本 :.Jf0  
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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： zsX1QN16  
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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。 /Z~<CbKKl  
余下的脚本计算与屈光度有关的所有参数。 'gC_)rK*  
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分析 x3 q]I8q  
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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。 LhOa{1SY  
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脚本代码 $c0h.t  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. [x+FcXb  
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Dim entity As T_ENTITY dIN$)?aB0  
Dim op As T_OPERATION _FpTFf
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Dim mat As T_MODELMATERIAL U>]$a71  
Dim A As Double Q.l}NtHwV  
Dim pupilDiam As Double 0AZ")<^~7  
Dim eID As Long =/s>Q l  
Dim parID As Long a1C{(f)  
Dim count As Integer |bTPtrT8  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double sDPs G5q<  
Dim tlens As Double, nlens As Double W42iu"@  
Dim curv As Double, conic As Double B"h#C!E  
Dim ok As Long ED=V8';D  
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Sub Main ^2Fei.?T.  
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    '用户输入对话框 #|L8tuWW  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 r_ I5.gK  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ?zh9d%R  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 @.$|w>>T  
        OKButton 40,91,90,21 /rWd=~[MO  
        CancelButton 190,91,90,21 ojaws+(& y  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 >3p\m  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Bt@^+vH ~  
    End Dialog 01wX`"I  
    Dim dlg As UserDialog cG[l!Z  
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    ok = Dialog (dlg) C 3^JAP  
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    If ok=0 Then    'cancel button was pressed VCV"S>aVf  
        Print "Execution cancelled." 6wBx;y |  
        End S0zD"T  
    End If @$ne{2J3  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ?qPo=~y01  
    If dlg.TextBox1 = "" Then ~ksi</s  
        A = 0           'Default accommodation my(2;IJ#{  
    Else mWoAO@}Y  
        A = CDbl(dlg.TextBox1) CDsSrKhx  
    End If J"!vu.[  
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    If dlg.TextBox2 = "" Then m8A#~i .  
        pupilDiam = 4   'Default pupil diameter 94h]~GqNi  
    Else -.1y(k^4E  
        pupilDiam = CDbl(dlg.TextBox2) e|)hG8FlF  
    End If `F-/QX[:  
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    Print " " i6^twK)j  
    Print "Accommodation = " & A & " Diopters" (/=f6^}  
    Print "Pupil Diameter = " & pupilDiam & " mm" /a{la8Ni  
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    ' Calculate new parameters with accommodation ,f~J`3(&  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness &Y!-%{e  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens F^WP<0C  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens p2#)A"  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {x|[p_?  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens K*%9)hq  
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    tlens = 3.767 + 0.04*A                  'Lens thickness @@R7p  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction = I:.X ;  
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    'Adjust parameters to account for accommodation I4'5P}1yp  
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    '************************************************************************* #*D)Q/k  
    'Aqueous thickness (Position of Lens) MX$0Op  
    '************************************************************************* C].iCxn  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) *{YlN}vA  
    GetCustomElement eID, entity V\>K]mwD  
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    parID = FindFullName( "Geometry.Arizona Eye" ) WYH
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    ' Delete any shift(s) in z 8NxM4$nQX  
    count = 0 7S-ys+  
    While GetOperationCount(eID)>count ]s]vZ  
        GetOperation eID, count, op ?Y
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        If op.Type="ShiftZ" Then Nkjza:f{  
            DeleteOperation eID,count xqeyD*s  
            count=count-1 VQ(jpns5  
        End If H['N  
        count=count+1 UxbjA- U[  
    Wend t#V!8EpBg  
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    'Set new shift in @D.}\(  
    op.Type = "ShiftZ" Sxnpq Vbk  
    op.val1 = taq &b.=M>\9Q  
    op.parent = parID v:f}XK<  
    AddOperation eID, op -C;^3R[ O  
    Print "Set aqueous humor thickness = " & taq-0.55 5-|:^hU9  
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    '************************************************************************* aAZZ8V  
    'Radius and conic constant of anterior lens cm&nd'A't  
    '************************************************************************* '<jyw   
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;%B(_c  
    GetConic eID, entity, curv, conic cbNTj$'b2u  
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    SetConic eID, entity, 1/Rant, CCant Umz KY  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ls_'')yp  
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    '************************************************************************* 68NYIyTW9  
    'Radius and conic constant of posterior lens (lXGmx8  
    '************************************************************************* S{Kiy#ltWc  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) FTH|9OP
  
    GetConic eID, entity, curv, conic ZXu>,Jy  
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    SetConic eID, entity, 1/Rpost, CCpost )#EGTRdo  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Bgn
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    '************************************************************************* v6[!o<@"a  
    'Lens thickness (Position of posterior lens surface) \<&m&%Zs  
    '************************************************************************* cW~}:;D4  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) rK@8/?y5  
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    ' Delete any z-shift(s) ;PF`Wj  
    count = 0 gD0eFTN  
    While GetOperationCount(eID)>count l3KVW5-!gS  
        GetOperation eID, count, op dl.N.P7}4  
        If op.Type="ShiftZ" Then a_[Eh fE  
            DeleteOperation eID,count BIb4h   
            count=count-1 s6ZuM/Q  
        End If tf=6\p  
        count=count+1
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    Wend =
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    'Set new z-shift @+;$jRwq  
    op.Type = "ShiftZ" f& 0M*o,)  
    op.val1 = tlens Hj'xAtx5  
    op.parent = parID :Gv1?M  
    AddOperation eID, op b[__1E9v'  
    Print "Set lens thickness = " & tlens AG3>V+k{Lv  
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    '************************************************************************* eiuSvyY  
    'Lens index of refraction h&|[eZt?F  
    '************************************************************************* ];}Wfl  
    eID = FindMaterial( "Lens" ) PvR6 z0  
    GetModelMaterial eID, mat 7wWFr  
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    mat.Nd = nlens /;{P}-H`ei  
    SetModelMaterial eID, mat ?42<J%p  
    Print "Set lens index of refraction = " & nlens yxonRV$&  
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    '************************************************************************* ,c$,!.r  
    'Pupil diameter F^l[GdUosK  
    '************************************************************************* A_n7w  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) r~[Ia!U?  
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    'Adjust pupil diameter (trimming volume inner hole) uvg
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" rI{=WPI&WU  
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    ' Adjust pupil location to just in front of the lens cD@(/$wt  
    parID = FindFullName( "Geometry.Arizona Eye" ) w;D+y*2  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) J%8(kWQ|  
    count = 0 ::o lN  
    While GetOperationCount(eID)>count )Z[ft  
        GetOperation eID, count, op yZd +^QN  
        If op.Type="ShiftZ" Then "vA}FV%tRq  
            DeleteOperation eID,count s.EI`*xylY  
            count=count-1 O[# 27_dH  
        End If M-\Y"]sW  
        count=count+1 XV!6dh!  
    Wend X"MB|Ny  
    op.Type = "ShiftZ" dCb`xR}  
    op.val1 = taq-0.01 TPVVck-T8  
    op.parent = parID w'L\?pI  
    AddOperation eID, op U2$d%8G  
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    Print "Set pupil diameter = " & pupilDiam h"lX4  
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    'Update AZ Eye subassembly Description =5aDM\L$&  
    eID = FindFullName( "Geometry.Arizona Eye" ) >O1[:%Z1  
    GetEntity eID, entity + r!1<AAE$  
    entity.Description = "Accommodation = " & A & "D" YZP(tn  
    SetEntity eID, entity Xsa2(-  
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    Update SH3|sXH<  
    Print "DONE!" n-5W*zk1  
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End Sub aHlcfh9|  
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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： Gn&-X]Rrl  
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Accommodation = 4 Diopters A2^\q>_#  
Pupil Diameter = 4 mm W8Q|$ZJ88F  
Set aqueous humor thickness = 2.81 ttXXy3G#  
Set anterior lens radius = 10.4 and conic constant = -2.375869 yPM3a7-Bm  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 NxSu3e~PS  
Set lens thickness = 3.927 :z}MIuf  
Set lens index of refraction = 1.42672 %509\;el  
Set pupil diameter = 4 F1iGMf-8  
DONE! #G|qD  
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