[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ?zu{&aOX|  
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。 mcG$V0D <{  
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模型 OF
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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。 r2'rfpQ  
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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. =lD]sk  
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光源 <]^D({`  
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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。 %/on\*Vh3  
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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。 Af<>O$$6  
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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。 :n9^:srGZH  
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视网膜的散射 2GzpWV(  
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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。 2&URIQg*
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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。 n<*]`do,w  
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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： 3)SZVME1Z  
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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。 J}CK|}  
余下的脚本计算与屈光度有关的所有参数。 W<o0Z OO  
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分析 *rT(dp!Y  
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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。 !k9h6/b6  
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脚本代码 P.DWC'IBN  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. F9w&!yW:  
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Dim entity As T_ENTITY uD5yw#`  
Dim op As T_OPERATION 926oM77  
Dim mat As T_MODELMATERIAL Hc|U@G  
Dim A As Double [rU8 #4.  
Dim pupilDiam As Double :`1g{8.+  
Dim eID As Long k1zt|  
Dim parID As Long 2"mj=}y6  
Dim count As Integer rK|&u v*b  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8ZfIh   
Dim tlens As Double, nlens As Double \-ws[  
Dim curv As Double, conic As Double ]i2\2MTW8  
Dim ok As Long 5AU3s  
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Sub Main wkA!Jv%  
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    '用户输入对话框 }* JMc+!9@  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ?GU!ke p  
        TextBox 220,21,40,21,.TextBox1 'default: 0 'U$VOq?!  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 :G/]rDtd  
        OKButton 40,91,90,21 W[<":NX2  
        CancelButton 190,91,90,21 ! -@!u   
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ,5*xE\9G  
        TextBox 220,49,40,21,.TextBox2 'default: 4 :exuTn  
    End Dialog E,yK` mPp^  
    Dim dlg As UserDialog %=y3  
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    ok = Dialog (dlg) #)}bUNc'  
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    If ok=0 Then    'cancel button was pressed 2tm-:CPG  
        Print "Execution cancelled." \zL7j4  
        End I.1l
  
    End If KdsvZim0>  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Uy|=A7Ad c  
    If dlg.TextBox1 = "" Then -wMW@:M_  
        A = 0           'Default accommodation 2!?z%s-S  
    Else #2ASzCe  
        A = CDbl(dlg.TextBox1) [qMdOY%jx  
    End If ER1mA:8>E  
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    If dlg.TextBox2 = "" Then BM~niW;k  
        pupilDiam = 4   'Default pupil diameter 3eP0v  
    Else Kg-X]yu*0  
        pupilDiam = CDbl(dlg.TextBox2) L b;vrh;A  
    End If E9 q;>)}  
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    Print " " aZGDtzNG5h  
    Print "Accommodation = " & A & " Diopters" q%Jy
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    Print "Pupil Diameter = " & pupilDiam & " mm" 4,ynt&  
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    ' Calculate new parameters with accommodation i9k]Q(o  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness y$V)^-U>fw  

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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens zb}+ m#q  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens QF/u^|f  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens k|Yv8+XT  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens &ntP~!w  
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    tlens = 3.767 + 0.04*A                  'Lens thickness m{dyVE  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L^{;jgd&T9  
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    'Adjust parameters to account for accommodation A-C)w/7  
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    '************************************************************************* x$J
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    'Aqueous thickness (Position of Lens) L(2P|{C  
    '************************************************************************* #IGoz|m  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) T_tDpq_|  
    GetCustomElement eID, entity X+E\]X2  
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    parID = FindFullName( "Geometry.Arizona Eye" ) OK
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    ' Delete any shift(s) in z [aZ v?Z  
    count = 0 t^_{5  
    While GetOperationCount(eID)>count .>64h H  
        GetOperation eID, count, op v&b.Q:h*'  
        If op.Type="ShiftZ" Then }-q`&1!t
 
            DeleteOperation eID,count VIYksv   
            count=count-1 3s_
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        End If Pn'(8bRm  
        count=count+1 2]aZe4H.  
    Wend io r [v  
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    'Set new shift in .4C[D{4  
    op.Type = "ShiftZ" Lr?4Y  
    op.val1 = taq ncJFB,4  
    op.parent = parID J6( RlHS;  
    AddOperation eID, op L+~YCat|$U  
    Print "Set aqueous humor thickness = " & taq-0.55 7?!Z+r  
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    '************************************************************************* ]%<Q:+38  
    'Radius and conic constant of anterior lens 1u"*09yZd  
    '************************************************************************* XL7;^AE^Wl  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Ns!3- Y  
    GetConic eID, entity, curv, conic L740s[,`o#  
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    SetConic eID, entity, 1/Rant, CCant {~p7*
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Ng'Z
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    '************************************************************************* `zzKD2y  
    'Radius and conic constant of posterior lens h/X5w4  
    '************************************************************************* Q%n{*py  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) =2nn "YVP  
    GetConic eID, entity, curv, conic v :+8U[x  
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    SetConic eID, entity, 1/Rpost, CCpost [UJEU~XC  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost si^4<$Nr%j  
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    '************************************************************************* A`x -L  
    'Lens thickness (Position of posterior lens surface) &vFqe,Z  
    '************************************************************************* q M_/  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) O@r.>  
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    ' Delete any z-shift(s) 'ybth
 
    count = 0 Ev+HWx~Y  
    While GetOperationCount(eID)>count 'wz\tT^  
        GetOperation eID, count, op ;J(rw  
        If op.Type="ShiftZ" Then YXX36  
            DeleteOperation eID,count :>P4L,Da]  
            count=count-1 UR1JbyT  
        End If S$jV|xKB  
        count=count+1 r:c@17  
    Wend *^@#X-NG  
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    'Set new z-shift <'}b*wUB  
    op.Type = "ShiftZ" n^iNo  
    op.val1 = tlens :Su#xI  
    op.parent = parID <?LfOSdMs^  
    AddOperation eID, op Z;GIlgK9  
    Print "Set lens thickness = " & tlens G`]v_`>  
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    '************************************************************************* @K$VV^wp  
    'Lens index of refraction 1p7cv~#95  
    '************************************************************************* =My}{n[  
    eID = FindMaterial( "Lens" ) :DdBn.  
    GetModelMaterial eID, mat +mfe*'AU  
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    mat.Nd = nlens L$+d.=]  
    SetModelMaterial eID, mat }W:*aU  
    Print "Set lens index of refraction = " & nlens jl.okWuiY  
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    '************************************************************************* W.,% 0cZ  
    'Pupil diameter 1R=)17'O  
    '************************************************************************* =tr1*s{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) `z|
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    'Adjust pupil diameter (trimming volume inner hole) {OB-J\7Y  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" jM5_8nS&d  
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    ' Adjust pupil location to just in front of the lens r]A"Og_U  
    parID = FindFullName( "Geometry.Arizona Eye" ) lLuID  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) uY^v"cw/F  
    count = 0 xS6(K  
    While GetOperationCount(eID)>count #ZG3|#Q=L  
        GetOperation eID, count, op x9&-(kBU  
        If op.Type="ShiftZ" Then B4]AFRI  
            DeleteOperation eID,count #yW.o'S+  
            count=count-1 -O|&c9W.O  
        End If EY+/.=$x  
        count=count+1 3@^MvoC  
    Wend slU  
    op.Type = "ShiftZ" qqncl
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    op.val1 = taq-0.01 eeuZUf+~]  
    op.parent = parID +>JdYV<?0  
    AddOperation eID, op ^"3\iA:  
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    Print "Set pupil diameter = " & pupilDiam L
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    'Update AZ Eye subassembly Description e8$l0gzaD  
    eID = FindFullName( "Geometry.Arizona Eye" ) TT'Ofvdc  
    GetEntity eID, entity N>
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    entity.Description = "Accommodation = " & A & "D" Lltc4Mzw  
    SetEntity eID, entity &^V~cJ  
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    Update YiD-F7hf.*  
    Print "DONE!" _p\629`  
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End Sub -x{dc7y2  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： e# t3u_  
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Accommodation = 4 Diopters R)ERxz#  
Pupil Diameter = 4 mm kr%2w  
Set aqueous humor thickness = 2.81 Y
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Set anterior lens radius = 10.4 and conic constant = -2.375869 >D 97c|?c  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 g3Z:{@m  
Set lens thickness = 3.927 7 _`L$<-n  
Set lens index of refraction = 1.42672 _@Y"$V]=Vt  
Set pupil diameter = 4 CJJD@=  
DONE! m9Ax\lf  
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