[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 TGU:(J'^  
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。 D|@bGN  
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模型 vBh;  
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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。 &5\^f?'b7  
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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. b4>``n  
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光源 X E|B)Q(  
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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。 q7X}MAW  
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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。 w8O" =},  
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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。 ;{vwBDV!'  
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视网膜的散射 #/Ruz'H1>  
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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。 ]' Y|Nl  
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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。 4&QUh+F  
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脚本 zuSq+pxL@  
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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： {
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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。 <$%X<sDkq  
余下的脚本计算与屈光度有关的所有参数。 x2co>.
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分析 rcV-_+KE(B  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 n]Zk;%yL  
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脚本代码 ~@T<gA9V  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ';0 qj$#  
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Dim entity As T_ENTITY @@@=}!<H=  
Dim op As T_OPERATION /kgeV4]zR  
Dim mat As T_MODELMATERIAL [}OgSP9i  
Dim A As Double Xa," 'r  
Dim pupilDiam As Double u:&o}[  
Dim eID As Long LCs__.  
Dim parID As Long {Z> M  
Dim count As Integer ^Dg<Ki  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]5}=^  
Dim tlens As Double, nlens As Double n`ViTwd]MQ  
Dim curv As Double, conic As Double &$'z  
Dim ok As Long o!OMm!  
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Sub Main 0fm*`4Q  
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    '用户输入对话框 eujK4s  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 lhH`dG D
 
        TextBox 220,21,40,21,.TextBox1 'default: 0 ST5V!jz  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 iYJZvN  
        OKButton 40,91,90,21 #*9-d/K  
        CancelButton 190,91,90,21 .B72C[' c  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 `Out(Hn  
        TextBox 220,49,40,21,.TextBox2 'default: 4 3*ixlO:qGk  
    End Dialog POAw M  
    Dim dlg As UserDialog U!(@q!>G  
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    ok = Dialog (dlg) 7j$Pt8$  
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    If ok=0 Then    'cancel button was pressed 0nJE/JZ  
        Print "Execution cancelled." xYfD()w<I  
        End eS+g|$c
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    End If :s={[KBP  
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    'Assign accommodation and pupil diameter & use defaults if field left empty @{hd{>K*  
    If dlg.TextBox1 = "" Then q%(EYM5Y  
        A = 0           'Default accommodation C NsNZJ  
    Else @I`C#~  
        A = CDbl(dlg.TextBox1) urBc=3Rz  
    End If %FZ2xyI.  
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    If dlg.TextBox2 = "" Then %" D%:  
        pupilDiam = 4   'Default pupil diameter 6$U]9D  
    Else t5B7I59  
        pupilDiam = CDbl(dlg.TextBox2) <TGn=>u  
    End If hR#-u1C  
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    Print " " 1Xu?(2;NF  
    Print "Accommodation = " & A & " Diopters" q h/F  
    Print "Pupil Diameter = " & pupilDiam & " mm" B* kcNlW  
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    ' Calculate new parameters with accommodation A4C+5R  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness x5}'7
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens !Ucjax~  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 54lu2gD'  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens cH' iA.  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens N`@NiJ(O;  
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    tlens = 3.767 + 0.04*A                  'Lens thickness b-ll  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction "@R>J?Cc+  

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    'Adjust parameters to account for accommodation d)f@ 5/<  
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    '************************************************************************* PZxAH9 S?  
    'Aqueous thickness (Position of Lens) >r`b_K  
    '************************************************************************* m!<i0thJ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) U,#yqER'r  
    GetCustomElement eID, entity }En  
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    parID = FindFullName( "Geometry.Arizona Eye" ) F+R?a+e  
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    ' Delete any shift(s) in z O[tvR:Nh  
    count = 0 k@zy  
    While GetOperationCount(eID)>count oSiMpQu08  
        GetOperation eID, count, op A.<H>=Z#O  
        If op.Type="ShiftZ" Then ;g{qYj_  
            DeleteOperation eID,count O~j> ?  
            count=count-1 Grs]d-xI  
        End If {{V8;y  
        count=count+1 |*Z$E$k:  
    Wend ? WJ> p  
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    'Set new shift in #/PAA  
    op.Type = "ShiftZ" ~wg:!VWA)  
    op.val1 = taq zvABU+{jD  
    op.parent = parID V5+SWXZ  
    AddOperation eID, op SGb;!T*  
    Print "Set aqueous humor thickness = " & taq-0.55 " \I4u{zC  
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    '************************************************************************* ;^t{Il'j  
    'Radius and conic constant of anterior lens ~l;[@jsw F  
    '************************************************************************* r0p w_j  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) d%l{V6  
    GetConic eID, entity, curv, conic %%(R@kh9  
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    SetConic eID, entity, 1/Rant, CCant {U&.D [{&  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant rG,5[/l  
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    '************************************************************************* 06jqQ-_`h  
    'Radius and conic constant of posterior lens ss;R8:5  
    '************************************************************************* +`?Y?L^ J  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) KNH1#30 K  
    GetConic eID, entity, curv, conic (sVi\R  
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    SetConic eID, entity, 1/Rpost, CCpost E=){K  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [M+f-kl  
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    '************************************************************************* 1lv2@QH9  
    'Lens thickness (Position of posterior lens surface) v[Kxja;  
    '************************************************************************* oK 6(HF'&  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) CI3XzH\IX*  
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    ' Delete any z-shift(s) @?h/B=56  
    count = 0
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    While GetOperationCount(eID)>count Y@PI {;!  
        GetOperation eID, count, op 2NB L}x  
        If op.Type="ShiftZ" Then q^6+!&"  
            DeleteOperation eID,count L(X6-M:  
            count=count-1 |_ua
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        End If 'Ei;^Y 1e  
        count=count+1 b!M"VDjQ  
    Wend 7FRmx4(!  
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    'Set new z-shift `a9L%z  
    op.Type = "ShiftZ" qKJSj   
    op.val1 = tlens TX#m&vh  
    op.parent = parID >}(CEzc8  
    AddOperation eID, op #-h\.#s  
    Print "Set lens thickness = " & tlens kI%%i>Y}  
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    '************************************************************************* Qt|c1@J  
    'Lens index of refraction A&>.74}p  
    '************************************************************************* ^iQn'++
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    eID = FindMaterial( "Lens" ) 4lZ$;:Jg  
    GetModelMaterial eID, mat Y#g4$"G9  
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    mat.Nd = nlens k__$Q9qj(  
    SetModelMaterial eID, mat dx;k`r$w  
    Print "Set lens index of refraction = " & nlens S4=R^];l  
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    '************************************************************************* E= `6-H{  
    'Pupil diameter LdB($4,  
    '************************************************************************* JMTvSXr  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) u :F~K  
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    'Adjust pupil diameter (trimming volume inner hole) 5+fLeC;  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" p019)X|vx  
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    ' Adjust pupil location to just in front of the lens *3D%<kVl  
    parID = FindFullName( "Geometry.Arizona Eye" ) , lJv  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" )  YBnA+l*  
    count = 0 `%j~|i
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    While GetOperationCount(eID)>count `)QCn<  
        GetOperation eID, count, op 5aa<qtUjH  
        If op.Type="ShiftZ" Then
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            DeleteOperation eID,count lSH6>0#B  
            count=count-1 J/3_C6U
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        End If A=kH%0s2p@  
        count=count+1 u a\,->  
    Wend }6 K^`!  
    op.Type = "ShiftZ" VM0j`bs'K*  
    op.val1 = taq-0.01 ++DG5`  
    op.parent = parID x|{IwA9  
    AddOperation eID, op R<V!%rL;;  
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    Print "Set pupil diameter = " & pupilDiam B4]`-mahO  
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    'Update AZ Eye subassembly Description sCu+Lg~f  
    eID = FindFullName( "Geometry.Arizona Eye" ) tlA"B{7  
    GetEntity eID, entity kHqztg  
    entity.Description = "Accommodation = " & A & "D" Zy09L}59P  
    SetEntity eID, entity +Y+Y6Ac[}  
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    Update *cO sv  
    Print "DONE!" SI8%M=P>  
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End Sub f0T,ul,  
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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： B7z -7&TE  
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Accommodation = 4 Diopters n>'Kp T9|  
Pupil Diameter = 4 mm @}:uu$OH  
Set aqueous humor thickness = 2.81 F0690v0mB[  
Set anterior lens radius = 10.4 and conic constant = -2.375869 `g,8-  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 `ImE% r!  
Set lens thickness = 3.927 1J'3g  
Set lens index of refraction = 1.42672 C2{lf^9:&  
Set pupil diameter = 4 FW.$5*f='  
DONE! `N5|Ho*C  
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