[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 oe1$;K>.7  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 /80RO:'7  
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模型 D"s ]dQ$r  
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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。 "xMnD(p  
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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. iFB {a?BE  
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光源 I
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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。 OR-fC  
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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。 r=^?  
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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。 \9jvQV/y  
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视网膜的散射 T.#Vma  
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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。 8al%
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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。 \6c8Lqa  
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脚本 85]3y%f9  
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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： )i*-j=  
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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。 3!0~/8!f@  
余下的脚本计算与屈光度有关的所有参数。 pv;ZR  
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分析 o[E|xw  
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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。 ubQZTAx  
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脚本代码 q[MZSg  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. sAfNu~d  
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Dim entity As T_ENTITY 4-veO3&.h  
Dim op As T_OPERATION MY"8!  
Dim mat As T_MODELMATERIAL <WRrB `nO  
Dim A As Double }D\i1/Y  
Dim pupilDiam As Double Bi$nYV)-l  
Dim eID As Long 55#s/`gd)^  
Dim parID As Long Z@{e\
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Dim count As Integer Rx%SeM2  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &'d3Yt  
Dim tlens As Double, nlens As Double :B"Y3
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Dim curv As Double, conic As Double Fl0 :Z  
Dim ok As Long <maYS2  
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Sub Main R8![ $mkU  
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    '用户输入对话框  {;| >Qn  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 RDWUy(iX  
        TextBox 220,21,40,21,.TextBox1 'default: 0 pGdo:L?  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 rf]'VJg#3  
        OKButton 40,91,90,21 TZYz`l+v  
        CancelButton 190,91,90,21 $PE{}`#g  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 sxFkpf_h  
        TextBox 220,49,40,21,.TextBox2 'default: 4 2
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    End Dialog ~s4o1^6L  
    Dim dlg As UserDialog yTwtGo&  
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    ok = Dialog (dlg) HHcWyu  
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    If ok=0 Then    'cancel button was pressed IMtfi(Y%F  
        Print "Execution cancelled." 4J${gcju  
        End /<-@8CC<  
    End If qGrUS_~q*  
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    'Assign accommodation and pupil diameter & use defaults if field left empty [OK(  
    If dlg.TextBox1 = "" Then _q<Ke/  
        A = 0           'Default accommodation E[kf%\  
    Else l11+sqg  
        A = CDbl(dlg.TextBox1) g:]X '%Ub  
    End If 0JS#{EDh+  
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    If dlg.TextBox2 = "" Then {]V+C=`  
        pupilDiam = 4   'Default pupil diameter hX&Jq%{oa  
    Else Z/~7N9?m(  
        pupilDiam = CDbl(dlg.TextBox2) FvVR \a  
    End If Xah-*]ET  
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    Print " " LZF%bJv  
    Print "Accommodation = " & A & " Diopters" O|I)HpG;  
    Print "Pupil Diameter = " & pupilDiam & " mm" !aQQq[  
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    ' Calculate new parameters with accommodation \PJpy^i  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Zm+QhnY|  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens d:SLyFD$q  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 5nSi2
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens z(g6$Y{  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens CS|al(?~  
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    tlens = 3.767 + 0.04*A                  'Lens thickness V~!lY\  

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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction (N 0kTi]b  
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    'Adjust parameters to account for accommodation rS&"UH?c7  
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    '************************************************************************* v| Yh]y  
    'Aqueous thickness (Position of Lens) SL ) ope  
    '************************************************************************* Z0#&D&2sV  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :N>n1tHL;A  
    GetCustomElement eID, entity 8LH\a.>  
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    parID = FindFullName( "Geometry.Arizona Eye" ) lNs;-`I~  
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    ' Delete any shift(s) in z 0LD$"0v/C3  
    count = 0 %(YU*Tf~  
    While GetOperationCount(eID)>count }{y(&Oy3Y  
        GetOperation eID, count, op CD:$22*]  
        If op.Type="ShiftZ" Then YQ$EN>.eO  
            DeleteOperation eID,count K);)$8K  
            count=count-1 G%FLt[  
        End If i2&I<:  
        count=count+1 lV M)'m  
    Wend Yx3ivjX.>  
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    'Set new shift in KMll8X  
    op.Type = "ShiftZ" VV$4NV&`Q  
    op.val1 = taq Q@0Zh,l  
    op.parent = parID PL|zm5923  
    AddOperation eID, op Sk7sxy<F'  
    Print "Set aqueous humor thickness = " & taq-0.55 gUWW}*\ U  
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    '************************************************************************* %yPjPUHy  
    'Radius and conic constant of anterior lens G5,g$yNs  
    '************************************************************************* qac8zt#2 C  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) M7gb3gw6  
    GetConic eID, entity, curv, conic K'\Jnn  
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    SetConic eID, entity, 1/Rant, CCant ?mn&b G  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Bk2j|7  
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    '************************************************************************* U~I y),5  
    'Radius and conic constant of posterior lens aExt TE  
    '************************************************************************* 4H*M^?h\#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ?"-1QG  
    GetConic eID, entity, curv, conic B]#^&89wG)  
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    SetConic eID, entity, 1/Rpost, CCpost 1uco{JX<S  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ifI0s)Pn  
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    '************************************************************************* /1h ${mo~  
    'Lens thickness (Position of posterior lens surface) &N.]8x5A  
    '************************************************************************* h$l`)AH^  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" )
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    ' Delete any z-shift(s) BT^HlW<  
    count = 0 ":!1gC  
    While GetOperationCount(eID)>count u9u'!hAGH  
        GetOperation eID, count, op noZ!j>f{@l  
        If op.Type="ShiftZ" Then Mb:>  
            DeleteOperation eID,count }uiD8b{I  
            count=count-1 LZ}m;  
        End If %;,4qB  
        count=count+1 "@YtxYTW-  
    Wend zK>}x=  
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    'Set new z-shift $[0\Th  
    op.Type = "ShiftZ" Jp"[`
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    op.val1 = tlens 6Z<|L^  
    op.parent = parID oer3DD(  
    AddOperation eID, op FBeo@  
    Print "Set lens thickness = " & tlens 6%Pvh- ~_  
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    '************************************************************************* sL],@z8<k  
    'Lens index of refraction 3?Fe(!@  
    '************************************************************************* uaqV)H  
    eID = FindMaterial( "Lens" ) O`Y@U?^N  
    GetModelMaterial eID, mat M'nzoRk  
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    mat.Nd = nlens WDJ rN  
    SetModelMaterial eID, mat q{l %k  
    Print "Set lens index of refraction = " & nlens #'4Psz  
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    '************************************************************************* MDCwgNPiQW  
    'Pupil diameter K"cV7U rE  
    '************************************************************************* nT9Hw~f<j  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) n(#[[k9&Ic  
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    'Adjust pupil diameter (trimming volume inner hole) vLpIVNA]]Y  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" kTA4!654  
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    ' Adjust pupil location to just in front of the lens Ctbc!<@o  
    parID = FindFullName( "Geometry.Arizona Eye" ) rP IAu[],g  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !b?
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    count = 0 9B/iQCFtj$  
    While GetOperationCount(eID)>count C8%MKNPd  
        GetOperation eID, count, op w\a6ga!xt"  
        If op.Type="ShiftZ" Then =w7+Yt  
            DeleteOperation eID,count |3BxNFe`%  
            count=count-1  0:$pJtx"  
        End If e4FR)d0x  
        count=count+1 <B!DwMk;.  
    Wend X/h|;C*9  
    op.Type = "ShiftZ" ;Irn{O  
    op.val1 = taq-0.01 U+[h^M$U  
    op.parent = parID <vt}+uMzXv  
    AddOperation eID, op Ro=dgQ0:t  
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    Print "Set pupil diameter = " & pupilDiam q4g)/x%nc  
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    'Update AZ Eye subassembly Description 4'"WD0  
    eID = FindFullName( "Geometry.Arizona Eye" ) ~-UO^$M-  
    GetEntity eID, entity .:O($9^Ho  
    entity.Description = "Accommodation = " & A & "D" 84coi  
    SetEntity eID, entity 4m6/ba  
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    Update yp
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    Print "DONE!" K{:[0oIHc  
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End Sub S R s  
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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： 3R%y
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Accommodation = 4 Diopters v8zOY#?  
Pupil Diameter = 4 mm :3{n(~  
Set aqueous humor thickness = 2.81 yd[4l%G(zS  
Set anterior lens radius = 10.4 and conic constant = -2.375869 }*S`1IWMj  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 In8{7&iVO  
Set lens thickness = 3.927 \Nk578+AA  
Set lens index of refraction = 1.42672 <o/lK\>  
Set pupil diameter = 4 -/Zy{2 <u  
DONE! R ^ZOcONd-  
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