[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 {Mj- $G"  
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。 0i"2s}^+_  
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模型 Qn|8Ic` *  
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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。 ~3-"1E>Rgy  
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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. s FJ:09L|  
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光源 }D+ b`,  
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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。 *DvX||`&  
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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。 #?+[|RS|  
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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。 j^;P=L0=  
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视网膜的散射 }Xk_ xQVt{  
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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。 "wcw`TsK  
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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。 mA$86X_  
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脚本 IiRQ-,t1  
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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： z. X hE \  

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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。 (3$DUvx7  
余下的脚本计算与屈光度有关的所有参数。 [&4+ <Nl'  
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分析 i].E1},%  
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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。 K?[Vz[-Fc  
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脚本代码 BfCM\ij  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 9d^m 7}2  
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Dim entity As T_ENTITY 9xj }<WM  
Dim op As T_OPERATION hu} vYA7ZH  
Dim mat As T_MODELMATERIAL 9B;WjXSe  
Dim A As Double [zm@hxym  
Dim pupilDiam As Double /n(0w`
 
Dim eID As Long #:N#i  
Dim parID As Long Lfcy#3!  
Dim count As Integer ,SNrcwv  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ZklpnL*!  
Dim tlens As Double, nlens As Double *P9"1K+  
Dim curv As Double, conic As Double $0K@=7ms  
Dim ok As Long T[xIn+w  
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Sub Main P(Rl/eyRM  
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    '用户输入对话框 P*?|E@;s`  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vdvnwzp!l  
        TextBox 220,21,40,21,.TextBox1 'default: 0 .%7Le|Fb"  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 L~)8Q(f  
        OKButton 40,91,90,21 Cw(ypu  
        CancelButton 190,91,90,21 YLTg(*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 1$Q[%9  
        TextBox 220,49,40,21,.TextBox2 'default: 4 GTTEg{  
    End Dialog (B$>o.
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    Dim dlg As UserDialog :<B_V<  
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    ok = Dialog (dlg) ;92xSe"Ww  
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    If ok=0 Then    'cancel button was pressed %L]sQq,  
        Print "Execution cancelled." Hcg7u7M{  
        End "0Z/|&  
    End If 6'N_bNW  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 6lg]5d2CD  
    If dlg.TextBox1 = "" Then _*?qOmf=
 
        A = 0           'Default accommodation 1hCU"|VH:  
    Else D8u`6/^  
        A = CDbl(dlg.TextBox1) UCmy$aW  
    End If ebJTrh<{  
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    If dlg.TextBox2 = "" Then Rh)XYCM  
        pupilDiam = 4   'Default pupil diameter @$^4Av-  
    Else L5zCL0j`  
        pupilDiam = CDbl(dlg.TextBox2) N0^SWA|S  
    End If 4FZR }e\  
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    Print " " ^yc8is'`  
    Print "Accommodation = " & A & " Diopters" PDw+Q  
    Print "Pupil Diameter = " & pupilDiam & " mm" \xggIW.^0  
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    ' Calculate new parameters with accommodation 6Y\TVRR  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness _+aR|AEC  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens v'?o#_La+  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens #"!ga)a%L  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens v@GhwL  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens +:ms`Sr>  
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    tlens = 3.767 + 0.04*A                  'Lens thickness $'5rS$]a/  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction u&S0  
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    'Adjust parameters to account for accommodation vxk0@k_  
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    '************************************************************************* p6BDhT(RS  
    'Aqueous thickness (Position of Lens) 0U*f"5F  
    '************************************************************************* 8N"WKBj|_d  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) =8tK]lb  
    GetCustomElement eID, entity <+q`Dk  
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    parID = FindFullName( "Geometry.Arizona Eye" ) \ILNx^$EL  
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    ' Delete any shift(s) in z pL[3,.@WA  
    count = 0 3V^5 4_  
    While GetOperationCount(eID)>count yl@Nyu  
        GetOperation eID, count, op u8>aO>(bVg  
        If op.Type="ShiftZ" Then y>E:]#F  
            DeleteOperation eID,count n CX{tqy   
            count=count-1 p9 ,[kb  
        End If YRBJ(v"9  
        count=count+1 '-N5F  
    Wend MS#*3Md&y  
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    'Set new shift in -eh .Tk  
    op.Type = "ShiftZ" T*#M'H7LSQ  
    op.val1 = taq %vZHHBylu  
    op.parent = parID d(V4;8a0  
    AddOperation eID, op | Z7j s"  
    Print "Set aqueous humor thickness = " & taq-0.55 j[\:#/J  
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    '************************************************************************* &0bq3JGW  
    'Radius and conic constant of anterior lens J;wB
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    '************************************************************************* tw zV-8\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) YCb|eS^u  
    GetConic eID, entity, curv, conic
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    SetConic eID, entity, 1/Rant, CCant ZD|F"v.  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant (*6 .-Xn  
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    '************************************************************************* }s'=w]m  
    'Radius and conic constant of posterior lens C<T6l'S{?  
    '************************************************************************* iQ2}*:Jc$  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) M"p%CbcI]  
    GetConic eID, entity, curv, conic zx]r.V  
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    SetConic eID, entity, 1/Rpost, CCpost V*2*5hx  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [
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    '************************************************************************* owA8hGF  
    'Lens thickness (Position of posterior lens surface) $vO<v<I'Gb  
    '************************************************************************* }m^^6h  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) [ypE[   
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    ' Delete any z-shift(s) 80g}<Lwc  
    count = 0 >vXJ9\  
    While GetOperationCount(eID)>count "0 %fR"  
        GetOperation eID, count, op 9yTDuhJ6  
        If op.Type="ShiftZ" Then |k]]dP|:'  
            DeleteOperation eID,count :a2[d1  
            count=count-1 w;Fy/XQ  
        End If HfH_jnR*  
        count=count+1 ^q& Rl\  
    Wend PcZ<JJ16F$  
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    'Set new z-shift \/S
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    op.Type = "ShiftZ" Yuf+d-%  
    op.val1 = tlens 6+ptL-Zt<  
    op.parent = parID e2V;6N  
    AddOperation eID, op %1#|>^  
    Print "Set lens thickness = " & tlens vyWx{@  
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    '************************************************************************* NPO!J^^  
    'Lens index of refraction `.pd %\  
    '************************************************************************* Tyaqa0  
    eID = FindMaterial( "Lens" ) bYem0hzOe  
    GetModelMaterial eID, mat ) d'H&c3  
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    mat.Nd = nlens vNd
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    SetModelMaterial eID, mat =Xid"$  
    Print "Set lens index of refraction = " & nlens 9+<A7PM1
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    '************************************************************************* rbv  
    'Pupil diameter ~Hg*vCd ?  
    '************************************************************************* :wRfk*Ly  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) )`Qr=DIsW  
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    'Adjust pupil diameter (trimming volume inner hole) Ywt9^M|z;  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" GeB-4img  
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    ' Adjust pupil location to just in front of the lens yD!GgnW  
    parID = FindFullName( "Geometry.Arizona Eye" ) vg X7B4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) W:wSM*  
    count = 0 E;4dlL`*  
    While GetOperationCount(eID)>count 6kR3[]:16v  
        GetOperation eID, count, op \f Kn} ]kG  
        If op.Type="ShiftZ" Then wpQp1){%Q  
            DeleteOperation eID,count x+'Ea.^  
            count=count-1 4XiQ8
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        End If 9|@5eN:N  
        count=count+1 C~.\2D`zy  
    Wend $5\sV48f  
    op.Type = "ShiftZ" oL>o*/  
    op.val1 = taq-0.01 2p 7;v7)y  
    op.parent = parID 7rGp^  
    AddOperation eID, op 4wEkxCWp/  
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    Print "Set pupil diameter = " & pupilDiam apM)$  
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    'Update AZ Eye subassembly Description *N{k#d/  
    eID = FindFullName( "Geometry.Arizona Eye" ) cL#zE  
    GetEntity eID, entity QiV
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    entity.Description = "Accommodation = " & A & "D" `8\"3S  
    SetEntity eID, entity ) R5[aO  
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    Update LKZ<\% X  
    Print "DONE!" k
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End Sub KNP^k$=)3c  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： {VM^K1  
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Accommodation = 4 Diopters Gcxz$.(  
Pupil Diameter = 4 mm -Fop<q\b  
Set aqueous humor thickness = 2.81 W5Jb5  
Set anterior lens radius = 10.4 and conic constant = -2.375869 $|!3ks  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 6
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Set lens thickness = 3.927 .K#' Fec  
Set lens index of refraction = 1.42672 "18cD5-#  
Set pupil diameter = 4 CA$|3m9)NM  
DONE! EQHCw<e  
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