[技术]Arizona眼睛模型 [复制链接]

简介 b"Jr_24t3v  
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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。 .R^ R|<x  
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模型 &#OF,_6"m  
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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。 $"va8,  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. #"C
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光源 g+Y &rz  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 )~IOsTjI  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 Ml/K
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 s+^1\  
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视网膜的散射 #TcX5  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 IR32O,)  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 j"+6aD/lv  
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脚本 lB7/oa1]>  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： OaY]}4tI$  
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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。 21] K7  
余下的脚本计算与屈光度有关的所有参数。 3f:]*U+O  
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分析 9l,8:%X_  
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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。 oWggh3eXk  

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脚本代码 [=:
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. AP9\]qZ(7  
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Dim entity As T_ENTITY )=5*iWe  
Dim op As T_OPERATION }I
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Dim mat As T_MODELMATERIAL z_). -  
Dim A As Double iztgk/(+G  
Dim pupilDiam As Double )-1$y+s>  
Dim eID As Long $U2Jq@G*  
Dim parID As Long [P]M)vJ**  
Dim count As Integer 5U*${  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 1+l[P9?R[  
Dim tlens As Double, nlens As Double bHzZ4i  
Dim curv As Double, conic As Double hJX;/~L  
Dim ok As Long [TT:^F(Y  
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Sub Main X*e:MRw[  
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    '用户输入对话框 N8!e(YK_  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 #Zn+-Ih  
        TextBox 220,21,40,21,.TextBox1 'default: 0 F^!mgU X  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 p4K 8L'nZ  
        OKButton 40,91,90,21 Iapzhy2l  
        CancelButton 190,91,90,21 y;hco  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 (unJwh{7Q  
        TextBox 220,49,40,21,.TextBox2 'default: 4 HBw0
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    End Dialog j>~@vq  
    Dim dlg As UserDialog NNRKYdp,  
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    ok = Dialog (dlg) + Cq&~<B  
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    If ok=0 Then    'cancel button was pressed u7-0?  
        Print "Execution cancelled." UQtG<W]<  
        End /!y3ZzL  
    End If 1z3I^gI*i  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ]O~/k~f  
    If dlg.TextBox1 = "" Then 8)J,jh9q  
        A = 0           'Default accommodation >~&7D`O  
    Else p\xsW"=8q  
        A = CDbl(dlg.TextBox1) > !HC ?  
    End If *Oy%($'  
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    If dlg.TextBox2 = "" Then dw7h@9\y  
        pupilDiam = 4   'Default pupil diameter `$[`C/h  
    Else o2LUB)=R'  
        pupilDiam = CDbl(dlg.TextBox2) $U%N$_k?  
    End If 2f9%HX(5  
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    Print " " 3N{ ZX{}  
    Print "Accommodation = " & A & " Diopters" PmDar<m  
    Print "Pupil Diameter = " & pupilDiam & " mm" 1{wOjq(4  
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    ' Calculate new parameters with accommodation $7\hszjZ  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness }$s._)a  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens |CjdmQ u  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens w"j[c#vM  

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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {>#4{D00  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ;[-y>qU0  
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    tlens = 3.767 + 0.04*A                  'Lens thickness {7FD-Q[tS  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction =+wkjTO  
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    'Adjust parameters to account for accommodation QBT_H"[  
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    '************************************************************************* N~M-|^L  
    'Aqueous thickness (Position of Lens) L|w}#|-  
    '************************************************************************* O.P:~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) K7d]p0d'  
    GetCustomElement eID, entity <' b%  
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    parID = FindFullName( "Geometry.Arizona Eye" ) !rgdOlTR^  
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    ' Delete any shift(s) in z O7T wM Yh  
    count = 0 -"3<Ll  
    While GetOperationCount(eID)>count *AN2&>Y  
        GetOperation eID, count, op ^2um.`8  
        If op.Type="ShiftZ" Then 2<5s0GT'/  
            DeleteOperation eID,count !8>tT  
            count=count-1 `=~d^wKYJ3  
        End If WqRg/  
        count=count+1 Nv
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    Wend ,LJX  
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    'Set new shift in $+a2CZs!  
    op.Type = "ShiftZ" C$$lJ=>  
    op.val1 = taq 
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    op.parent = parID DvvjIYB~  
    AddOperation eID, op q9c:,k  
    Print "Set aqueous humor thickness = " & taq-0.55 KA$l.6&d  
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    '************************************************************************* \
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    'Radius and conic constant of anterior lens lTpmoDa%  
    '************************************************************************* S[cVoV  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) *.0#cP7 "  
    GetConic eID, entity, curv, conic bPtbU:G  
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    SetConic eID, entity, 1/Rant, CCant Y r^C+Oyg  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant @[4Tdf  
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    '************************************************************************* j*jO809%^  
    'Radius and conic constant of posterior lens 9*}?0J8  
    '************************************************************************* S_B;m1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) CvtG  
    GetConic eID, entity, curv, conic Yj^n4G(h  
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    SetConic eID, entity, 1/Rpost, CCpost 9L'R;H?L  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost wA<#E6^vG  
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    '************************************************************************* 0UvN ws  
    'Lens thickness (Position of posterior lens surface) NPM}w!  
    '************************************************************************* ?5!>k^q  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %Ot^G%34  
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    ' Delete any z-shift(s) IU`&h2KZ.  
    count = 0 V{[vIt*  
    While GetOperationCount(eID)>count lT3,G#(  
        GetOperation eID, count, op fK|F`F2V  
        If op.Type="ShiftZ" Then @iwg`j6ol  
            DeleteOperation eID,count f|1GlUA{t  
            count=count-1 S5Q$dAL  
        End If tc@([XqH  
        count=count+1 T.zUerbO  
    Wend `AA[k  
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    'Set new z-shift S&@uY#_(*T  
    op.Type = "ShiftZ" KS/1ux4x  
    op.val1 = tlens 6*/o  
    op.parent = parID DM%4V|F"  
    AddOperation eID, op nkp!kqJ09  
    Print "Set lens thickness = " & tlens L+PrV y  
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    '************************************************************************* i!30f^9D-S  
    'Lens index of refraction L s=2!  
    '************************************************************************* <=*xwI&q  
    eID = FindMaterial( "Lens" ) &zr..i4O  
    GetModelMaterial eID, mat c"3 a
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    mat.Nd = nlens I"^ `!8<q  
    SetModelMaterial eID, mat {<a(1#{  
    Print "Set lens index of refraction = " & nlens b<B|p|  
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    '************************************************************************* 
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    'Pupil diameter N6Fj}m&E  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) J}qk:xGL  
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    'Adjust pupil diameter (trimming volume inner hole) \ qc8;"@  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" \w!G  
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    ' Adjust pupil location to just in front of the lens nl|}_~4U  
    parID = FindFullName( "Geometry.Arizona Eye" ) z6vRTY  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" )
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    count = 0 XX5 ):1  
    While GetOperationCount(eID)>count N?H;fK4v  
        GetOperation eID, count, op h5G>FPM-=  
        If op.Type="ShiftZ" Then rHu#  
            DeleteOperation eID,count iq '3.-xYr  
            count=count-1 `5;O|qRq  
        End If AAkdwo  
        count=count+1 zm}4=Kz}  
    Wend %Ysu613mz  
    op.Type = "ShiftZ" 2P8JLT*Tj  
    op.val1 = taq-0.01 $Xw .iN]g  
    op.parent = parID <D4.kM  
    AddOperation eID, op +d6/*}ht  
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    Print "Set pupil diameter = " & pupilDiam `?PZvGi  
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    'Update AZ Eye subassembly Description Rx*T
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    eID = FindFullName( "Geometry.Arizona Eye" ) *Wv]DV=\  
    GetEntity eID, entity >De\2gbJ  
    entity.Description = "Accommodation = " & A & "D" o_p//S#q  
    SetEntity eID, entity e@s+]a8D-k  
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    Update 
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    Print "DONE!" |n3PznV  
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End Sub BclZsU=xn  
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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： %O;"Z`I  
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Accommodation = 4 Diopters SC`.VCfc.  
Pupil Diameter = 4 mm Dg/&m*Yl  
Set aqueous humor thickness = 2.81 AZxx%6  
Set anterior lens radius = 10.4 and conic constant = -2.375869 0ANqEQX  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 `~[zIq:}7  
Set lens thickness = 3.927 VcT(n7  
Set lens index of refraction = 1.42672 H1f){L97wR  
Set pupil diameter = 4 s,N%sO;  
DONE! ;g: TsYwM