[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 n^qwE
 
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。 '< >Q20  
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模型 D]'8BS3  
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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。 e_rEu'[av  
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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. tv`c"Pb  
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光源 %7\l+g,  
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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。 |vG?H#y  
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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。 C\bJ_vl;'  
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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。 M#8_Qbvfk  
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视网膜的散射 2*n~r  
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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。 mv$gL  
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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。 }^n"t>Z8  
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脚本 =|^R<#%/  
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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： 0NvicZ7VR  
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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。 6s
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余下的脚本计算与屈光度有关的所有参数。 ^O"o-3dte  
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分析 g+4x  
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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。 zx?|5=+!  
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脚本代码 S1i~r+jf  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. m^tf=O<  
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Dim entity As T_ENTITY 9wC='  
Dim op As T_OPERATION PvxU.  
Dim mat As T_MODELMATERIAL V
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Dim A As Double ]<_v;Q<t  
Dim pupilDiam As Double Qgo|\=  
Dim eID As Long _2}/rwVg  
Dim parID As Long Z?eedVV@  
Dim count As Integer B/JMH 1r  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }[;r-5}  
Dim tlens As Double, nlens As Double M=5hp&=  
Dim curv As Double, conic As Double .&KC2#4  
Dim ok As Long 7U&<{U<  
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Sub Main @Ps1.  
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    '用户输入对话框 EM'#'fBZ>Y  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Z =*h9,MY  
        TextBox 220,21,40,21,.TextBox1 'default: 0 `TDS4Y  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 "haJwV6-  
        OKButton 40,91,90,21 u6*0% Km  
        CancelButton 190,91,90,21 LdX'V]ITh  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 v dU)
  
        TextBox 220,49,40,21,.TextBox2 'default: 4 0\o5+  
    End Dialog 7wbpQ&1_  
    Dim dlg As UserDialog CG
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    ok = Dialog (dlg) ^8g<>,$  
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    If ok=0 Then    'cancel button was pressed [](] "r  
        Print "Execution cancelled." OI^qX;#Kd  
        End zhI"++  
    End If i6:O9Km  
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    'Assign accommodation and pupil diameter & use defaults if field left empty RJD(c#r$  
    If dlg.TextBox1 = "" Then 6[a;83  
        A = 0           'Default accommodation -9q3]nmT(  
    Else VzuU0  
        A = CDbl(dlg.TextBox1) Gmmh&Uj  
    End If uNvdlY]  
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    If dlg.TextBox2 = "" Then {jEEAH)  
        pupilDiam = 4   'Default pupil diameter x 4`RKv2m  
    Else *XG.?%x*|  
        pupilDiam = CDbl(dlg.TextBox2) W`jKe-jF  
    End If kclZ+E  
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    Print " " z3|5E#m  
    Print "Accommodation = " & A & " Diopters" ~Z;.np(T  
    Print "Pupil Diameter = " & pupilDiam & " mm" Ce@"+k+w  
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    ' Calculate new parameters with accommodation ]l=iKl  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 4{ED~w|  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ua%j
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens tAS[T9B  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Tl-Ix&37  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 7,R ~2ss5z  
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    tlens = 3.767 + 0.04*A                  'Lens thickness LP//\E_]  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction RnUud\T/  
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    'Adjust parameters to account for accommodation d+IN-lR(  
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    '************************************************************************* ,o6,(jJU  
    'Aqueous thickness (Position of Lens) idY Xv)R  
    '************************************************************************* l\{r-F N  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) VJ-To}  
    GetCustomElement eID, entity E-HK=D&W/  
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    parID = FindFullName( "Geometry.Arizona Eye" ) S+-V16{i  
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    ' Delete any shift(s) in z g"X!&$
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    count = 0 Q6%Pp_$k  
    While GetOperationCount(eID)>count &B} ,xcNO  
        GetOperation eID, count, op LOe l6Ui  
        If op.Type="ShiftZ" Then ~{{@m]P  
            DeleteOperation eID,count Ihx[S!:  
            count=count-1 Gs(;&fw  
        End If Y?JB%%WWI  
        count=count+1 zB#.EW  
    Wend C&RZdh,$  
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    'Set new shift in 18ON`j  
    op.Type = "ShiftZ" d+&w7/F  
    op.val1 = taq (bGk=q=M  
    op.parent = parID WTu1t]  
    AddOperation eID, op |:LklpdYe  
    Print "Set aqueous humor thickness = " & taq-0.55 kC/An@J^#  
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    '************************************************************************* BYb"[qPV  
    'Radius and conic constant of anterior lens {R5_=MG  
    '************************************************************************* w)"F=33}5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) zKNac[:  
    GetConic eID, entity, curv, conic r/RX|M  
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    SetConic eID, entity, 1/Rant, CCant dIk9C|-.  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant co>IJzg  
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    '************************************************************************* snyA  
    'Radius and conic constant of posterior lens 
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    '************************************************************************* `/o|1vv@_  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) #[sJKW  
    GetConic eID, entity, curv, conic $~'G<YYF4  
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    SetConic eID, entity, 1/Rpost, CCpost fY 10a_@x  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost cs)R8vuB)z  
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    '************************************************************************* *xDV8iu_  
    'Lens thickness (Position of posterior lens surface) :qtg`zM/4  
    '************************************************************************* FQ]5W |e  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) XZj3x',;  
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    ' Delete any z-shift(s) ])vqXjN6"  
    count = 0 Kj#h9e  
    While GetOperationCount(eID)>count Eg$Er*)h8  
        GetOperation eID, count, op /D;cm  
        If op.Type="ShiftZ" Then iy|xF~  
            DeleteOperation eID,count 6\6g-1B`  
            count=count-1 ,sltB3f  
        End If {"\pMY'7  
        count=count+1 P7;q^jlB  
    Wend z=qxZuFkDs  
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    'Set new z-shift xhncQhf\  
    op.Type = "ShiftZ" 'o1lJ?~kH  
    op.val1 = tlens kDc/]Zb%  
    op.parent = parID cEEnR1  
    AddOperation eID, op X'usd$[.  
    Print "Set lens thickness = " & tlens |i- S}M  
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    '************************************************************************* W ZW:q  
    'Lens index of refraction +(oExp(!  
    '************************************************************************* zu``F]B  
    eID = FindMaterial( "Lens" ) ^aY,Wq  
    GetModelMaterial eID, mat P8GGN  
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    mat.Nd = nlens K#]FUUnj=  
    SetModelMaterial eID, mat %wIb@km  
    Print "Set lens index of refraction = " & nlens hu:x,;`9H  
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    '************************************************************************* C40W@*6S2  
    'Pupil diameter m<|fdS'@  
    '************************************************************************* ^PowL:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 3q`Uq`t4mR  
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    'Adjust pupil diameter (trimming volume inner hole) H@`lM~T[  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" gOkum_  
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    ' Adjust pupil location to just in front of the lens @0iXqM#jH  
    parID = FindFullName( "Geometry.Arizona Eye" ) 6R!AIOD>  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 8%^W<.Y  
    count = 0 Lg+cHaA  
    While GetOperationCount(eID)>count (sEZNo5n  
        GetOperation eID, count, op 5hp)Z7  
        If op.Type="ShiftZ" Then +$B#] ,  
            DeleteOperation eID,count 9HD5A$  
            count=count-1 d&%}u1 .  
        End If tdnd~WSR  
        count=count+1 =[`gfw  
    Wend -<^3!C >  
    op.Type = "ShiftZ" 3 /LW6W|  
    op.val1 = taq-0.01 :bz;_DZP  
    op.parent = parID }*56DX  
    AddOperation eID, op ~0Mw\p%}  
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    Print "Set pupil diameter = " & pupilDiam ilFS9A3P  
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    'Update AZ Eye subassembly Description P.O/ZW>g  
    eID = FindFullName( "Geometry.Arizona Eye" ) N-}|!pqb  
    GetEntity eID, entity Vet<,;Te  
    entity.Description = "Accommodation = " & A & "D" zA@w[.  
    SetEntity eID, entity ` NWmwmWB"  
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    Update ux>LciNq  
    Print "DONE!" | @p  
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End Sub 2G}@s.iE  
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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： wO"ezQ  
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Accommodation = 4 Diopters TV(%e4U=  
Pupil Diameter = 4 mm !&Us^Q^  
Set aqueous humor thickness = 2.81 +!"7=?}  
Set anterior lens radius = 10.4 and conic constant = -2.375869 (t"rzH  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 s7:w>,v/  
Set lens thickness = 3.927 'z">4{5  
Set lens index of refraction = 1.42672 5S&^mj-9  
Set pupil diameter = 4 10$:^  
DONE! :6}cczQE|O  
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