[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 k=}hY+/=  
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。 LLiX%XOh  
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模型 {wySH[V  
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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。 DK;-2K  
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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. |Sm/Uq(c  
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光源 zT"#9"["  
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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。 Sb.;$Be5g  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 Y!zlte|P  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 Q>$v~v?9  
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视网膜的散射 KC'{>rt7  
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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。 q=U=Y n  
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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。 Wp $\>  
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脚本 E@p9vf->  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： G6FknYj  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 7
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余下的脚本计算与屈光度有关的所有参数。 occ}|u  
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分析 [LE_lATjU  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 U<$|ET'  
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脚本代码 gO29:L[t  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. YvonZ  
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Dim entity As T_ENTITY lq7
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Dim op As T_OPERATION o}BaZ|iZ2  
Dim mat As T_MODELMATERIAL WE\V<MGS/  
Dim A As Double IIzdCa{l  
Dim pupilDiam As Double z?7pn}-  
Dim eID As Long b$hQB090  
Dim parID As Long ?(Nls.c  
Dim count As Integer /)N[tv2  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double >5\rU[H>  
Dim tlens As Double, nlens As Double Re`= B  
Dim curv As Double, conic As Double ne%ckW?ks  
Dim ok As Long qSON3Iid  
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Sub Main {B34^H:  
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    '用户输入对话框 W<t,Ivg  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1
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        TextBox 220,21,40,21,.TextBox1 'default: 0 N G4wtDa  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 f -bVcWI  
        OKButton 40,91,90,21 P:=3;d{v  
        CancelButton 190,91,90,21 I%
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1
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        TextBox 220,49,40,21,.TextBox2 'default: 4 h/d&P  
    End Dialog |VIBSty2d  
    Dim dlg As UserDialog t<rhrW75P  
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    ok = Dialog (dlg) )]'?yS"  
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    If ok=0 Then    'cancel button was pressed tR1 kn&w  
        Print "Execution cancelled." I_4'9  
        End tJc9R2  
    End If -rUn4a  
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    'Assign accommodation and pupil diameter & use defaults if field left empty uGOvZO^v  
    If dlg.TextBox1 = "" Then `zF=h#i  
        A = 0           'Default accommodation 0]&~ddL  
    Else S7@.s`_{w  
        A = CDbl(dlg.TextBox1) V1M oW;&  
    End If q*8^9
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    If dlg.TextBox2 = "" Then n>{>3?  
        pupilDiam = 4   'Default pupil diameter +v/_R{ M  
    Else *:wu{3g}M`  
        pupilDiam = CDbl(dlg.TextBox2) w[t!?(![>  
    End If p "u5wJ_  
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    Print " " .xS}/^8iD  
    Print "Accommodation = " & A & " Diopters" K[O'@v  
    Print "Pupil Diameter = " & pupilDiam & " mm" vk&C'&uV9@  
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    ' Calculate new parameters with accommodation k1W q$KCwG  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <rNCb;  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [;%qxAB/_  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens d H]'&&M  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens <GT&q <4w  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ZBi|BD  
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    tlens = 3.767 + 0.04*A                  'Lens thickness %&0_0BU  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction se2ay_<F+  
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    'Adjust parameters to account for accommodation 6x7pqHM  
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    '************************************************************************* >8\EdN59{  
    'Aqueous thickness (Position of Lens) Q
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    '************************************************************************* |p}qK Fdi  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0x*L
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    GetCustomElement eID, entity D<78Tm x  

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    parID = FindFullName( "Geometry.Arizona Eye" ) 1--_E,Su>  
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    ' Delete any shift(s) in z :_X9x{  
    count = 0 gmd-$%"  
    While GetOperationCount(eID)>count gP:
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        GetOperation eID, count, op ~RgO9p(dY  
        If op.Type="ShiftZ" Then wGr
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            DeleteOperation eID,count T*e>_\Tx  
            count=count-1 5srj|'ja  
        End If $)8b)Tb  
        count=count+1 Y%m^V?k  
    Wend =8#$'1K,v  
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    'Set new shift in ?VaWOwWI  
    op.Type = "ShiftZ" qVjl8%)  
    op.val1 = taq {]ie|>'=C  
    op.parent = parID lC):$W  
    AddOperation eID, op /i.3v45t"  
    Print "Set aqueous humor thickness = " & taq-0.55 8&+m5xS  
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    '************************************************************************* OFH!z{*  
    'Radius and conic constant of anterior lens pu3ly&T#a_  
    '************************************************************************* tn>z%6;&Z  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) <_(UAv  
    GetConic eID, entity, curv, conic {kVhht]X  
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    SetConic eID, entity, 1/Rant, CCant W(.q.Sx>  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant F-0|&0  
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    '************************************************************************* anxZ|DE  
    'Radius and conic constant of posterior lens t|XQFb@}  
    '************************************************************************* Cp{ j+Ia  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) jr,j1K@_t  
    GetConic eID, entity, curv, conic *>"k/XUn$  
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    SetConic eID, entity, 1/Rpost, CCpost St 4YNS.|  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `q":i>FP2  
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    '************************************************************************* y{{7)G  
    'Lens thickness (Position of posterior lens surface) Ed
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    '************************************************************************* I#?NxP\S  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *|97 g*G(  
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    ' Delete any z-shift(s) X=_`$ 0  
    count = 0 5BWO7F0v"  
    While GetOperationCount(eID)>count (x"TM),Q  
        GetOperation eID, count, op tw{V7r~n  
        If op.Type="ShiftZ" Then r92C^h0  
            DeleteOperation eID,count y<#?z 8P  
            count=count-1 9'tOF  
        End If >U?U;i  
        count=count+1 0uZ'j  
    Wend B{`4"uEb$G  
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    'Set new z-shift AC'$~4  
    op.Type = "ShiftZ" 7=Vs1TVc  
    op.val1 = tlens ZMFV iE;8  
    op.parent = parID ~x}/>-d  
    AddOperation eID, op <]9%Pm#X  
    Print "Set lens thickness = " & tlens Nw74T  
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    '************************************************************************* _hK83s4  
    'Lens index of refraction I)9un|+,y  
    '************************************************************************* ah1DuTT/G  
    eID = FindMaterial( "Lens" ) gA`x-`  
    GetModelMaterial eID, mat /d<"{\o  
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    mat.Nd = nlens ]6#7TT  
    SetModelMaterial eID, mat ]gxt+'iAFS  
    Print "Set lens index of refraction = " & nlens y}TiN!M  
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    '************************************************************************* =Tdh]0  
    'Pupil diameter }1N$4@  
    '************************************************************************* +1`Zu$|  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $8kQM  
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    'Adjust pupil diameter (trimming volume inner hole) N|G=n9p  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >%vw(pt  
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    ' Adjust pupil location to just in front of the lens SHM ?32'  
    parID = FindFullName( "Geometry.Arizona Eye" ) f{]eb1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) _'g'M=E  
    count = 0 QE
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    While GetOperationCount(eID)>count [8T  
        GetOperation eID, count, op ( Lp~:p  
        If op.Type="ShiftZ" Then E="FE.%A  
            DeleteOperation eID,count b7X-mkF  
            count=count-1 ,}9G|$  
        End If 0)c9X[sG  
        count=count+1 CTqAhL 4}  
    Wend >,ThIwRN  
    op.Type = "ShiftZ" ]6PX4oK_t  
    op.val1 = taq-0.01 W6kDQ&q  
    op.parent = parID ]}K\
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    AddOperation eID, op ^iWcuh_n  
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    Print "Set pupil diameter = " & pupilDiam R`7v3{  
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    'Update AZ Eye subassembly Description j_r?4k
 
    eID = FindFullName( "Geometry.Arizona Eye" ) vY+{zGF  
    GetEntity eID, entity 0zSRk]i.f  
    entity.Description = "Accommodation = " & A & "D" .I6:iB  
    SetEntity eID, entity lu]Z2xSv  
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    Update ]e*Zx;6oi  
    Print "DONE!" .Pp;%  
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End Sub /zB;1%m-  
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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： Q}a, f75  
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Accommodation = 4 Diopters 1x\Vz\  
Pupil Diameter = 4 mm =44hI86  
Set aqueous humor thickness = 2.81 kh11Y1Q0d  
Set anterior lens radius = 10.4 and conic constant = -2.375869 y:FxX8S$'e  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 L&C<-BA/  
Set lens thickness = 3.927 ,I(PDlvtM  
Set lens index of refraction = 1.42672 Qv3g 4iJ  
Set pupil diameter = 4
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DONE! Hh/Z4`&yi  
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