[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 X8C7d6ca  
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。 *z0!=>(  
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模型 -|>~I#vY  
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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。 5EYG
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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. U^m#!hp  
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光源 f{BF%;  
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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。 wh$bDTCj  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 #GzALF97  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 qTsy'y;Z  
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视网膜的散射 xo>0j#  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 GJ9>i)+h;  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 z8\YMr6o  
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脚本 l=DF)#>w  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： I&-r^6Yx  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 uw;Sfx,s  
余下的脚本计算与屈光度有关的所有参数。 4H{t6t@-:  
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分析 {&5lZ<nu8A  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 sfF~
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脚本代码 .a4,Lr#q.  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 8t!jo.g  
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Dim entity As T_ENTITY u*C*O4f>OC  
Dim op As T_OPERATION P:{Aqn~zR  
Dim mat As T_MODELMATERIAL s~M$Wo8  
Dim A As Double b A+_/1C  
Dim pupilDiam As Double 1T!o
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Dim eID As Long q?!HzZ  
Dim parID As Long `~XksyT  
Dim count As Integer s= %3`3Fo  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double H^d?(
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Dim tlens As Double, nlens As Double /.]u%;%r[  
Dim curv As Double, conic As Double xfRp_;l+R  
Dim ok As Long Kd:l8%+  
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Sub Main )7 57
 
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    '用户输入对话框 T5:Q_o]  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 8pnD6Lp>  
        TextBox 220,21,40,21,.TextBox1 'default: 0 od=hCQ1>  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 x Lan1V  
        OKButton 40,91,90,21 wAHuPQ&_Q  
        CancelButton 190,91,90,21 o`YBz~2  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 !v8
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        TextBox 220,49,40,21,.TextBox2 'default: 4 ?I+{S  
    End Dialog
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    Dim dlg As UserDialog 1KZigeHXI  
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    ok = Dialog (dlg) <$s6?
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    If ok=0 Then    'cancel button was pressed /EjXyrn2  
        Print "Execution cancelled." M-@RgWvF  
        End G_+/ e]P  
    End If cZVx4y%kz
 
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    'Assign accommodation and pupil diameter & use defaults if field left empty MT!Y!*-5  
    If dlg.TextBox1 = "" Then riW9l6s'  
        A = 0           'Default accommodation 2;gvo*k  
    Else JCcYFtW  
        A = CDbl(dlg.TextBox1) KElEGW  
    End If 8dR `T}  
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    If dlg.TextBox2 = "" Then 8UU
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        pupilDiam = 4   'Default pupil diameter x,C8):\t`B  
    Else 0/v]YK.  
        pupilDiam = CDbl(dlg.TextBox2) YE`Y t  
    End If r^5%0_F]  
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    Print " " .Y6v#VI  
    Print "Accommodation = " & A & " Diopters" lie,A  
    Print "Pupil Diameter = " & pupilDiam & " mm" C>|.0:[%  
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    ' Calculate new parameters with accommodation ~cc }yDe  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness /4T
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens /ZyMD(_J  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Ao\P|K9MyL  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens yeiIP  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ]hV!lG1_  
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    tlens = 3.767 + 0.04*A                  'Lens thickness \Y!#Y#c  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Nvd(?+c  
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    'Adjust parameters to account for accommodation 'LMj.#A<g  
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    '************************************************************************* vv.E6D^x(  
    'Aqueous thickness (Position of Lens) sT;wHtU  
    '************************************************************************* GQYR`;>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0B(s+#s  
    GetCustomElement eID, entity Rq|6d M6H  
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    parID = FindFullName( "Geometry.Arizona Eye" ) {wC*61@1  
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    ' Delete any shift(s) in z @eJ8wf]  
    count = 0 {dZ]+2Z~+  
    While GetOperationCount(eID)>count U;W9`JT<.f  
        GetOperation eID, count, op PIU@}:}  
        If op.Type="ShiftZ" Then x|m9?[ !_  
            DeleteOperation eID,count H
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            count=count-1 joI)6c  
        End If `,'/Sdr  
        count=count+1 Bf*>q*%B{  
    Wend fHd[8{;P:  
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    'Set new shift in OTF/Pu$  
    op.Type = "ShiftZ" '^TeV=  
    op.val1 = taq /K|(O^nw  
    op.parent = parID p{5m5x  
    AddOperation eID, op qHZDo[  
    Print "Set aqueous humor thickness = " & taq-0.55 PcC@}3  
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    '************************************************************************* "r46Rfa  
    'Radius and conic constant of anterior lens ]mMJ6n  
    '************************************************************************* &IN%2c  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) jMn,N9Mf  
    GetConic eID, entity, curv, conic SAdT#0J  
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    SetConic eID, entity, 1/Rant, CCant N" L&Z4Z  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ~yJ2@2I  
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    '************************************************************************* ~)f^y!PMQ  
    'Radius and conic constant of posterior lens
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    '************************************************************************* zx%WV@O9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Rq}lW.<r  
    GetConic eID, entity, curv, conic Mw0>p5+ cy  
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    SetConic eID, entity, 1/Rpost, CCpost :e7\z  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost @[lMh9`  
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    '************************************************************************* ],SQD3~9  
    'Lens thickness (Position of posterior lens surface) o=R(DK# U  
    '************************************************************************* 7}VqXUwabx  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^m%#1Zd  
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    ' Delete any z-shift(s) ] :;x,$k  
    count = 0 gl+d0<Rzw  
    While GetOperationCount(eID)>count K\2{SjL:B  
        GetOperation eID, count, op rD=D.1_   
        If op.Type="ShiftZ" Then 14 & KE3`  
            DeleteOperation eID,count uj6'T S
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            count=count-1 ?zBu`7j  
        End If ]i#p2?BR  
        count=count+1 YHEn{z7  
    Wend U|3!ixk>>w  
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    'Set new z-shift j4owo#OB-  
    op.Type = "ShiftZ" I5M\PK/  
    op.val1 = tlens ZHK>0>;  
    op.parent = parID ]$"eGHX  
    AddOperation eID, op 5VV}wR
 
    Print "Set lens thickness = " & tlens 0:v!'  
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    '************************************************************************* =3
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    'Lens index of refraction :$"{-n  
    '************************************************************************* >IIq_6Z#  
    eID = FindMaterial( "Lens" ) JjS+'A$A5  
    GetModelMaterial eID, mat mU-2s%X<.^  
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    mat.Nd = nlens w~u{"E$  
    SetModelMaterial eID, mat R->x_9y-
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    Print "Set lens index of refraction = " & nlens a|FkU%sjzZ  
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    '************************************************************************* ,m<YSMKX  
    'Pupil diameter \!\:p/f  
    '************************************************************************* J|BElBY  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) FC1rwXL(  
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    'Adjust pupil diameter (trimming volume inner hole) 6o^>q&e}%  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" W p)!G  
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    ' Adjust pupil location to just in front of the lens i%9vZ  
    parID = FindFullName( "Geometry.Arizona Eye" ) tLOGj?/r  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) eaFkDl  
    count = 0 kD#n/RBgf  
    While GetOperationCount(eID)>count  Lw\u{E@  
        GetOperation eID, count, op |<c9ZS+  
        If op.Type="ShiftZ" Then 0ZjT.Ep  
            DeleteOperation eID,count h*VDd3[#  
            count=count-1 &|XgWZS5  
        End If %<>:$4U@]  
        count=count+1 I#MPJ@*WT  
    Wend >.qFhO\1so  
    op.Type = "ShiftZ" 5b:1+5iF-  
    op.val1 = taq-0.01 ZhY{,sy?QO  
    op.parent = parID zls^JTE  
    AddOperation eID, op pX_  
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    Print "Set pupil diameter = " & pupilDiam Yd3lL:M  
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    'Update AZ Eye subassembly Description MUl`0H"tR  
    eID = FindFullName( "Geometry.Arizona Eye" ) ''9]`B,:a0  
    GetEntity eID, entity 0HWSdf|w  
    entity.Description = "Accommodation = " & A & "D" k)3N0]q6  
    SetEntity eID, entity R%3yxnM*  
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    Update >3/mV<g f  
    Print "DONE!"  b*Qd9  
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End Sub C?|sQcCE  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： ,&,%B|gT]  
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Accommodation = 4 Diopters e&x)g;bn  
Pupil Diameter = 4 mm wxHd^b  
Set aqueous humor thickness = 2.81 #+o$Tg  
Set anterior lens radius = 10.4 and conic constant = -2.375869 c$1
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 QqF<HCO  
Set lens thickness = 3.927 4vL\t uoz  
Set lens index of refraction = 1.42672 _zDS-e@  
Set pupil diameter = 4 j(y<oxh  
DONE! 7D<Aa?cv_l  
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