[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 sV'v* 1|  
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。 *8206[y  
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模型 ji##$xC  
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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。 0Bu*g LY  
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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. FF@`+T  
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光源 9}XT'+`y  
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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。 `5<1EGJsD  
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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。 iUCwKpb9
 
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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。 /Tcb\:`9  
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视网膜的散射 9;pzzZ  
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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。 uOb2npPj  
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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。 &*ZC0V3  
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脚本 sM0c#YK?  
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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： bCt_yR  
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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。 SCI1bMf  
余下的脚本计算与屈光度有关的所有参数。 7Qt2gf  
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分析 < )Alb\Z  
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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。 "u,sRbL  
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脚本代码 .?70=8{  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. "zXGp7Q'#  
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Dim entity As T_ENTITY .r(^h/IF  
Dim op As T_OPERATION |
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Dim mat As T_MODELMATERIAL R&#[6 r(h  
Dim A As Double ~DK F%}E  
Dim pupilDiam As Double [Yn;G7cK  
Dim eID As Long jjYM3LQcdP  
Dim parID As Long G^ K*+  
Dim count As Integer 8>2&h  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double xp~YIeSg  
Dim tlens As Double, nlens As Double .Dc28F~t  
Dim curv As Double, conic As Double Th_Q owk  
Dim ok As Long HUK"OH  
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Sub Main TS/Cp{  
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    '用户输入对话框 7:#  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 5FZ47m ~{Z  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ;gdi=>S_  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 (21']x  
        OKButton 40,91,90,21 `:V}1ioX5  
        CancelButton 190,91,90,21 r(pwOOx  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :EYu 4Y  
        TextBox 220,49,40,21,.TextBox2 'default: 4 QCVsVG!sN  
    End Dialog Lf[G>0t&n  
    Dim dlg As UserDialog bkxk i@t  
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    ok = Dialog (dlg) U0!^m1U:  
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    If ok=0 Then    'cancel button was pressed Zlr{L]c  
        Print "Execution cancelled." \nrgAC-b  
        End n9N#&Q"7m  
    End If \FIa,5k8  
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    'Assign accommodation and pupil diameter & use defaults if field left empty @gH(/pFX  
    If dlg.TextBox1 = "" Then (zjz]@qJ  
        A = 0           'Default accommodation 1 ,#{X3  
    Else w/?nUp  
        A = CDbl(dlg.TextBox1) @TdQZZ}G\x  
    End If BhOXXa{B  
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    If dlg.TextBox2 = "" Then )>-77\  
        pupilDiam = 4   'Default pupil diameter x-w`KFS  
    Else Lhl$w'r  
        pupilDiam = CDbl(dlg.TextBox2) JZWgr&O<  
    End If MFf05\aDu  
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    Print " " V"w`!  
    Print "Accommodation = " & A & " Diopters" $&ex\_W  
    Print "Pupil Diameter = " & pupilDiam & " mm" #;5[('&[  
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    ' Calculate new parameters with accommodation nYI/&B{p  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 4 *Bp  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens fO[Rf_  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |h#D
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 73&]En  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens dE 3i=  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ,[Dh2fPM,  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 1mT|o_K{ T  
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    'Adjust parameters to account for accommodation 0ClX  
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    '************************************************************************* 3X88x-3  
    'Aqueous thickness (Position of Lens) \e
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    '************************************************************************* 7xLo4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) se<i5JsSV  
    GetCustomElement eID, entity l-DGy#h+z  
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    parID = FindFullName( "Geometry.Arizona Eye" ) gi1}5DR  
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    ' Delete any shift(s) in z ^2&O3s
  
    count = 0 &*jxI[  
    While GetOperationCount(eID)>count 1?/5A|?V4+  
        GetOperation eID, count, op &,m'sQ  
        If op.Type="ShiftZ" Then +Fu@I{"A  
            DeleteOperation eID,count S(g<<Te  
            count=count-1 hN>('S-cq  
        End If  IgzCh  
        count=count+1 %f_)<NP9=
 
    Wend .fio<mqi  
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    'Set new shift in ?c|`R1D  
    op.Type = "ShiftZ" 
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    op.val1 = taq 1Y H4a|bc  
    op.parent = parID kr/1Dsr4  
    AddOperation eID, op ?=/}Ft  
    Print "Set aqueous humor thickness = " & taq-0.55 [oQ`HX1g  
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    '************************************************************************* ?:#>^eWYe7  
    'Radius and conic constant of anterior lens ]>VJ--fH  
    '************************************************************************* t7U,AQ=;P5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) eZ8Y"i\!y  
    GetConic eID, entity, curv, conic EWuiaw.  
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    SetConic eID, entity, 1/Rant, CCant o*O"\/pmF  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?L<UOv7;t  
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    '************************************************************************* N=O+X~  
    'Radius and conic constant of posterior lens H#1*'e>  
    '************************************************************************* 4%',scn  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Xa?6#
  
    GetConic eID, entity, curv, conic "6I-]:K-  
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    SetConic eID, entity, 1/Rpost, CCpost 9sfB+]}h  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost (/9.+V_  
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    '************************************************************************* h+zkVRyA  
    'Lens thickness (Position of posterior lens surface) S5*~r@8h  
    '************************************************************************* Z?.p%*>`T=  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) x8SM,2ud  
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    ' Delete any z-shift(s) }C`}wS3i  
    count = 0 3zA8pI w  
    While GetOperationCount(eID)>count ReHd~G9  
        GetOperation eID, count, op v)C:E9!|  
        If op.Type="ShiftZ" Then RF,=bOr19  
            DeleteOperation eID,count /QV. U.>G  
            count=count-1 |`q)/ 08b  
        End If Ads<-.R  
        count=count+1 G+ $)W u  
    Wend !"Oj$c -  
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    'Set new z-shift %/6e"o  
    op.Type = "ShiftZ" Gw\G+T?M-  
    op.val1 = tlens J1c&"Oh  
    op.parent = parID \ ]kb&Qw  
    AddOperation eID, op DiYJlD&  
    Print "Set lens thickness = " & tlens lE2wkY9^/  
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    '************************************************************************* jnU*l\,  
    'Lens index of refraction iZkW+5
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    '************************************************************************* .Kh(F6 s  
    eID = FindMaterial( "Lens" ) H(%] Os  
    GetModelMaterial eID, mat }VGI Y>v  
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    mat.Nd = nlens x^='pEt{  
    SetModelMaterial eID, mat ~*cY& 9  
    Print "Set lens index of refraction = " & nlens yqVaA 'w5  
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    '************************************************************************* P/gb+V=g!  
    'Pupil diameter @]ptY*   
    '************************************************************************* d4/`:?w  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) gGiV1jN_  
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    'Adjust pupil diameter (trimming volume inner hole) YP\4XI  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Q,,fDBN  
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    ' Adjust pupil location to just in front of the lens
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    parID = FindFullName( "Geometry.Arizona Eye" ) Lm*LJ_+ B  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) "-j@GCme  
    count = 0 m[xf./@f{  
    While GetOperationCount(eID)>count U+RCQTo  
        GetOperation eID, count, op A^r [_dyZ  
        If op.Type="ShiftZ" Then /nMqEHCyg  
            DeleteOperation eID,count 7AtXG^lK  
            count=count-1 ^?^|Y?f2P?  
        End If HDW\S#  
        count=count+1 3]kAb`9[K2  
    Wend G$x["  
    op.Type = "ShiftZ" `.sIZku  
    op.val1 = taq-0.01 TNyY60E  
    op.parent = parID Y^*$PED?  
    AddOperation eID, op ukDH@/  
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    Print "Set pupil diameter = " & pupilDiam )oxP.K8q)U  
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    'Update AZ Eye subassembly Description zk 'e6  
    eID = FindFullName( "Geometry.Arizona Eye" ) A^Hp#b@  
    GetEntity eID, entity "w|k\1D  
    entity.Description = "Accommodation = " & A & "D" BE2\?q-  
    SetEntity eID, entity a+a%}76N  
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    Update z5*O@_r+.b  
    Print "DONE!" 4;c_%=cU  
    
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End Sub ~tj7zI6  
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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： p_40V%y^  
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Accommodation = 4 Diopters pYhI{  
Pupil Diameter = 4 mm Bzy=@]`  
Set aqueous humor thickness = 2.81 ]'ApOp  
Set anterior lens radius = 10.4 and conic constant = -2.375869 DwrCysIK  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 )RCqsFjK  
Set lens thickness = 3.927 @Kb|  
Set lens index of refraction = 1.42672 k;:u| s8NS  
Set pupil diameter = 4 /h.3<HI."*  
DONE! &qI5*aQ8T  
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