[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 )%MC*Z:^  
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。 _"L6mcI6  
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模型 2M'dTXz  
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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。 BLO ]78  
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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. ){"?@1vP  
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光源 W_JO~P  
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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。 !e~[U-  
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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。 'u;O2$  
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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。 A8*zB=C  
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视网膜的散射 M\5|  
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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。 [%N?D#;  
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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。 m\0_1 #(  
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脚本 *??lwvJp  
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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： KRC"3Qt  
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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。
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余下的脚本计算与屈光度有关的所有参数。 h7UNmwj  
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分析 `IUn{I  
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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。 1d<Uwb>  
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脚本代码 bTaKB-  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. QH9t |l  
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Dim entity As T_ENTITY #Or;"}P>fB  
Dim op As T_OPERATION )_=2lu3%{  
Dim mat As T_MODELMATERIAL nOGTeKjEJ  
Dim A As Double D![v{0er  
Dim pupilDiam As Double W-n4wIj"  
Dim eID As Long Ec@n<KK#  
Dim parID As Long p2i?)+z  
Dim count As Integer WYUDD_m  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q,&Li+u|  
Dim tlens As Double, nlens As Double RDp  
Dim curv As Double, conic As Double akzGJ3g  
Dim ok As Long "+ou!YK+  
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Sub Main J{1H$[W~}  
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    '用户输入对话框 qJrT  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 j )6  
        TextBox 220,21,40,21,.TextBox1 'default: 0 
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 E5bVCAz  
        OKButton 40,91,90,21 ){5Nod{}a  
        CancelButton 190,91,90,21 LKu\Mh|  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 W-=6:y#A  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ;/j2(O^  
    End Dialog \g39>;iR  
    Dim dlg As UserDialog <h7cQ  
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    ok = Dialog (dlg) K -U}sW  
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    If ok=0 Then    'cancel button was pressed kt/,& oKI  
        Print "Execution cancelled." >1Z"5F7=  
        End l
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    End If J,2V&WuV0r  
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    'Assign accommodation and pupil diameter & use defaults if field left empty CI'RuR3y]Z  
    If dlg.TextBox1 = "" Then  p+h$]CH  
        A = 0           'Default accommodation `<C<[JP:o  
    Else f~`=I NrU  
        A = CDbl(dlg.TextBox1) uZ!YGv0^  
    End If hy5[ L`B  
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    If dlg.TextBox2 = "" Then to'7o8Z  
        pupilDiam = 4   'Default pupil diameter u5(8k_
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    Else wGc7  
        pupilDiam = CDbl(dlg.TextBox2) zfeT>S+  
    End If {{?g%mQ6  
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    Print " " o|kykxcq  
    Print "Accommodation = " & A & " Diopters" ,@`?I6nKy  
    Print "Pupil Diameter = " & pupilDiam & " mm" H@Z_P p?  
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    ' Calculate new parameters with accommodation k6(7G@@}  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness P!eo#b^S  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens +1ICX  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens m\L`$=eO8  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens $C4~v  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens $TI^8 3  
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    tlens = 3.767 + 0.04*A                  'Lens thickness s,HbW%s  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction u^" I3u8$  
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    'Adjust parameters to account for accommodation sTM;l,  
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    '************************************************************************* 6Y9N=\`  
    'Aqueous thickness (Position of Lens) No^gKh24  
    '************************************************************************* Nd~B$venh  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) X0lPRk53(  
    GetCustomElement eID, entity p['RV  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 36"n7  
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    ' Delete any shift(s) in z e97G]XLR  
    count = 0 |N.2iN:  
    While GetOperationCount(eID)>count 7oE0;'  
        GetOperation eID, count, op |R`"Zu`  
        If op.Type="ShiftZ" Then f9.?+.^_  
            DeleteOperation eID,count !J$r|IX5  
            count=count-1 sh<Q2X  
        End If $DbnPZ2$  
        count=count+1 J]F&4O  
    Wend Npp YUY  
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    'Set new shift in q~ H>rC(\  
    op.Type = "ShiftZ" %5o2I_Cjz  
    op.val1 = taq YKyno?m  
    op.parent = parID cS ~OxAS  
    AddOperation eID, op  :Sq]|)  
    Print "Set aqueous humor thickness = " & taq-0.55 g6GkA.!X$  
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    '************************************************************************* cU1o$NRx  
    'Radius and conic constant of anterior lens W__ArV2Z_  
    '************************************************************************* kwI``7g8*e  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 8Q'Emw |  
    GetConic eID, entity, curv, conic >Bt82ibN  
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    SetConic eID, entity, 1/Rant, CCant u#0snw~)/  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ]G/m,Zv*:  
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    '************************************************************************* GEBSUv
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    'Radius and conic constant of posterior lens -`O{iHfM|P  
    '************************************************************************* E/;t6&6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Hfcpqa  
    GetConic eID, entity, curv, conic Pfd1[~,  
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    SetConic eID, entity, 1/Rpost, CCpost g'"~'  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost >!963>DR  
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    '************************************************************************* ~Amq1KU*Z  
    'Lens thickness (Position of posterior lens surface) 8&<mg;H,  
    '************************************************************************* afm\Iv[*  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) >3 o4 U2  
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    ' Delete any z-shift(s) ,06Sm]4L,  
    count = 0 VYk:c`E  
    While GetOperationCount(eID)>count $7x2TiAL  
        GetOperation eID, count, op -f+#j
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        If op.Type="ShiftZ" Then YT\`R  
            DeleteOperation eID,count F/5&:e?( )  
            count=count-1 Ji4p6$ .j-  
        End If 7^L  
        count=count+1 0At0`Q#  
    Wend c*bvZC^6  
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    'Set new z-shift vFPY|Vzh  
    op.Type = "ShiftZ" MIMC(<  
    op.val1 = tlens 9LR=>@Z  
    op.parent = parID [vg&E )V  
    AddOperation eID, op )Z7Vm2a  
    Print "Set lens thickness = " & tlens X9x`i  
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    '************************************************************************* u]p21)m$x  
    'Lens index of refraction ,i>`Urd  
    '************************************************************************* K<S3gb?0  
    eID = FindMaterial( "Lens" ) l;-Ml{}|0  
    GetModelMaterial eID, mat *z0!=>(  
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    mat.Nd = nlens N J3;[qJ  
    SetModelMaterial eID, mat G m~ ./-  
    Print "Set lens index of refraction = " & nlens \"lz,bT  
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    '************************************************************************* !=0h*=NOYt  
    'Pupil diameter F};R  
    '************************************************************************* hU?DLl:bXF  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 'uL4ezTtA  
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    'Adjust pupil diameter (trimming volume inner hole) f{BF%;  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" wQxI({k@  
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    ' Adjust pupil location to just in front of the lens : auR0FE  
    parID = FindFullName( "Geometry.Arizona Eye" ) 0eY!Z._^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) gOF^?M11x  
    count = 0 w~Tg?RH:  
    While GetOperationCount(eID)>count )Sn0Y B  
        GetOperation eID, count, op g=Xf&}&=x  
        If op.Type="ShiftZ" Then f$I=oN  
            DeleteOperation eID,count atL<mhRz  
            count=count-1 X[BP0:`t  
        End If O(^h_  
        count=count+1 #a
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    Wend =?5)M_6)  
    op.Type = "ShiftZ" *EWWN?d  
    op.val1 = taq-0.01 K%q5:9m  
    op.parent = parID E&U_1D9=L<  
    AddOperation eID, op EU[\D;  
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    Print "Set pupil diameter = " & pupilDiam \|=6<ZY:  
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    'Update AZ Eye subassembly Description Fh#QS'[  
    eID = FindFullName( "Geometry.Arizona Eye" ) ;(C<gt,r}  
    GetEntity eID, entity *,\v|]fc  
    entity.Description = "Accommodation = " & A & "D" X^\D"fmE.  
    SetEntity eID, entity 'ZbWr*bo  
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    Update bRAD_  
    Print "DONE!" gAAC>{Wh  
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End Sub v,w af`)J  
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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： Fp\;j\pfw  
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Accommodation = 4 Diopters \jfK']P/H  
Pupil Diameter = 4 mm ibkB>n{(  
Set aqueous humor thickness = 2.81 ucN' zq  
Set anterior lens radius = 10.4 and conic constant = -2.375869 *yBVZD|?H  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 mnm ZO}  
Set lens thickness = 3.927 VLXA6+  
Set lens index of refraction = 1.42672 JK$3qUDnI  
Set pupil diameter = 4 8$IKQNS  
DONE! jVff@)_S  
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