[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 LuvY<~u  
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。 sN01rtB(UT  
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模型 ={@6{-tl  
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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。 ok\vQs(a  
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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. PP33i@G  
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光源 jkF
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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。 68C%B9.b'  
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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。 <FkFs{(t  
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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。 8\A#CQ5b  
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视网膜的散射 4*cEag   
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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。 B7E:{9l~s{  
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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。 Zaf:fsj>  
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脚本 9ZsVy
 
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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： ! Y~FLA_  
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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。 |a`Sc%  
余下的脚本计算与屈光度有关的所有参数。 ?(F6#"
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分析 )e=D(qd  
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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。 Q%f^)HZGR  
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脚本代码 _P 3G
  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. n&qg;TT  
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Dim entity As T_ENTITY M@H;pJ+B  
Dim op As T_OPERATION UapC"XYJ  
Dim mat As T_MODELMATERIAL S8wLmd>  
Dim A As Double L;NvcUFn  
Dim pupilDiam As Double 7<#U(,YEA  
Dim eID As Long c&
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Dim parID As Long g._]8{K  
Dim count As Integer qHplJ "  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double H.|#c^I  
Dim tlens As Double, nlens As Double f<fXsSv(  
Dim curv As Double, conic As Double D4lG[qb  
Dim ok As Long .*?wF  
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Sub Main t?-n*9,#S  
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    '用户输入对话框 aFb==73aLw  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ~"&|W'he[  
        TextBox 220,21,40,21,.TextBox1 'default: 0 {JO  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~Z?TFg  
        OKButton 40,91,90,21 L:pYn_  
        CancelButton 190,91,90,21 r?lf($D*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ~hnQUS`A  
        TextBox 220,49,40,21,.TextBox2 'default: 4 JPc+rfF  
    End Dialog 0y" $MC v  
    Dim dlg As UserDialog FxtQXu-g  
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    ok = Dialog (dlg) G%AbC"  
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    If ok=0 Then    'cancel button was pressed NMa}{*sQ  
        Print "Execution cancelled." g1/[eoZzk  
        End `iAF3:  
    End If 6xe*E[#k\  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Ustv{:7v  
    If dlg.TextBox1 = "" Then ,.83m%i  
        A = 0           'Default accommodation iwZPpl";  
    Else <EB+1GFuI  
        A = CDbl(dlg.TextBox1) @uqd.Q  
    End If ?Wr+Q  
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    If dlg.TextBox2 = "" Then 1MP~dRZ$  
        pupilDiam = 4   'Default pupil diameter 1#V_Z^OL  
    Else \:# L)  
        pupilDiam = CDbl(dlg.TextBox2) szZr4y<8|1  
    End If ]YnD  
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    Print " " hLd^ agX  
    Print "Accommodation = " & A & " Diopters" 7 S#J>*  
    Print "Pupil Diameter = " & pupilDiam & " mm" *v jmy/3  
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    ' Calculate new parameters with accommodation JgKO|VO  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness -LoZs ru  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens uB]7G0g:  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~:rl=o}  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {3>$[bT  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Yh@JXJ>  
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    tlens = 3.767 + 0.04*A                  'Lens thickness VuhGx:Xl  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction =V,mtT  
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    'Adjust parameters to account for accommodation _UMg[Um  
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    '************************************************************************* }>pknc?  
    'Aqueous thickness (Position of Lens) '%s.^kn  
    '************************************************************************* sQUM~HD\a  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) P%V'4pc  
    GetCustomElement eID, entity zsEc(  
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    parID = FindFullName( "Geometry.Arizona Eye" ) X:f UI4  
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    ' Delete any shift(s) in z Go`vfm"S  
    count = 0 j78i#}e  
    While GetOperationCount(eID)>count VZp5)-!\  
        GetOperation eID, count, op ,uSMQS-O'4  
        If op.Type="ShiftZ" Then tVYF{3BhA  
            DeleteOperation eID,count [`#CXq'  
            count=count-1 KB3Htw%W[+  
        End If 6y-@iJ*ld;  
        count=count+1 ^]>O;iB?  
    Wend {g'(~ qv  
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    'Set new shift in YquI$PV _  
    op.Type = "ShiftZ" [SjqOTon{  
    op.val1 = taq ttaM.  
    op.parent = parID i^/T  
    AddOperation eID, op MD}w Y><C  
    Print "Set aqueous humor thickness = " & taq-0.55 !j
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    '************************************************************************* .Yamc
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    'Radius and conic constant of anterior lens bWjc'P6rx  
    '************************************************************************* Q
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) pQyK={7?`  
    GetConic eID, entity, curv, conic bbDZ#DK"  
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    SetConic eID, entity, 1/Rant, CCant ]{;gw<T  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Q4#.X=.d  
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    '************************************************************************* +r�  
    'Radius and conic constant of posterior lens rX U  
    '************************************************************************* f%A;`4`q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 7m47rJyW4  
    GetConic eID, entity, curv, conic I }a`0Y&{  
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    SetConic eID, entity, 1/Rpost, CCpost o3XvRj  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost *[Imn\hu  
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    '************************************************************************* pN,u
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    'Lens thickness (Position of posterior lens surface) 77 Q5d"sIi  
    '************************************************************************* mtpeRVcF  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^7`BP%6  
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    ' Delete any z-shift(s) 3xy<tqfr  
    count = 0 IY1//9  
    While GetOperationCount(eID)>count 3#n_?-  
        GetOperation eID, count, op ]]HNd7Vh  
        If op.Type="ShiftZ" Then "-E\[@/  
            DeleteOperation eID,count =?5]()'*n  
            count=count-1 K,tQ!kk  
        End If <q)#  
        count=count+1 p .%]Q*8  
    Wend Ml`:UrU  
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    'Set new z-shift Q*GN`07@?d  
    op.Type = "ShiftZ" H
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    op.val1 = tlens iR HQ:Y!  
    op.parent = parID 3h]g}&k  
    AddOperation eID, op 7:e{;iG  
    Print "Set lens thickness = " & tlens xPdG*OcX!  
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    '************************************************************************* V~qNyOtA]  
    'Lens index of refraction pP1|&`}ux  
    '************************************************************************* gZV
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    eID = FindMaterial( "Lens" ) n5|fHk^s  
    GetModelMaterial eID, mat hy9\57_#  
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    mat.Nd = nlens BqEI(c6  
    SetModelMaterial eID, mat _OYasJUMG  
    Print "Set lens index of refraction = " & nlens m1b?J3  
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    '************************************************************************* g%o(+d  
    'Pupil diameter Xa[.3=bV?  
    '************************************************************************* >k|5Okq g  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) )',R[|<  
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    'Adjust pupil diameter (trimming volume inner hole) z>xmRs   
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" rV.}PtcF
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    ' Adjust pupil location to just in front of the lens 5#6|j?_a  
    parID = FindFullName( "Geometry.Arizona Eye" ) W
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Fk
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    count = 0 H;is/  
    While GetOperationCount(eID)>count *YI98  
        GetOperation eID, count, op XE
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        If op.Type="ShiftZ" Then /|w6:;$;mn  
            DeleteOperation eID,count 5{TsiZh4  
            count=count-1 qfF~D0}  
        End If 3qgS&js 7  
        count=count+1 _1X!EH"  
    Wend Xc++
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    op.Type = "ShiftZ" ?Rb9|`6  
    op.val1 = taq-0.01 P.se'z)E  
    op.parent = parID N>uRf0E>  
    AddOperation eID, op VO5#
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    Print "Set pupil diameter = " & pupilDiam xh-o}8*n"  
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    'Update AZ Eye subassembly Description t
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    eID = FindFullName( "Geometry.Arizona Eye" ) ;7*[Bcj.  
    GetEntity eID, entity t3WiomNCc  
    entity.Description = "Accommodation = " & A & "D"  ,i NXK  
    SetEntity eID, entity U)TUOwF  
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    Update 5PCqYN(:B  
    Print "DONE!" e)IzQ7Zex  
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End Sub =HK!(C  
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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： iO$8:mxm0?  
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Accommodation = 4 Diopters OG~gFZr)6  
Pupil Diameter = 4 mm 5&g@3j]  
Set aqueous humor thickness = 2.81 YRk(u7:0  
Set anterior lens radius = 10.4 and conic constant = -2.375869 gk4;>}  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 f^ZRT@`O  
Set lens thickness = 3.927 wSL}`CgU  
Set lens index of refraction = 1.42672 ,oe <  
Set pupil diameter = 4 2ACCh4(/P  
DONE! [Y/} ^  
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