[技术]Arizona眼睛模型 [复制链接]

简介 bk=;=K  
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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。 u^^jt(j  
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模型 h\Y~sm?
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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。 #"TYk@whWf  
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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. =Xid"$  
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光源 q2`mu4B  
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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。 L">jSZW[[  
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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。 ~X<$l+5  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 dikX_ Q>D  
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视网膜的散射 x+%> 2qgj"  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 Dh#5-Kf%  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 gwB0/$!4"  
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脚本 f`-vnh^+  
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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： \oGU6h<  
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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。 B 'd@ms  
余下的脚本计算与屈光度有关的所有参数。 4pcIH5)z  
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分析 S @!z'$&  
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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。 `@6y Wb:X  
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脚本代码 ^ rO}'~(  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ] ONmWo77o  
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Dim entity As T_ENTITY O_ $zK  
Dim op As T_OPERATION w'xPKO$bzR  
Dim mat As T_MODELMATERIAL 4/S3hH  
Dim A As Double DI-CC[  
Dim pupilDiam As Double HG5E,^1n  
Dim eID As Long g*4^HbVxt  
Dim parID As Long 81I9xqvSd~  
Dim count As Integer \l5G   
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double X6r<#n|l  
Dim tlens As Double, nlens As Double G-vkkNj%e  
Dim curv As Double, conic As Double g~=- ,j|  
Dim ok As Long j/ARTaO1]"  
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Sub Main (v}l#M7w  
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    '用户输入对话框 ,K&L/*  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 v.,D,6qZ  
        TextBox 220,21,40,21,.TextBox1 'default: 0 \vL{f;2J  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 &RHx8zScP  
        OKButton 40,91,90,21 zE}ry!{  
        CancelButton 190,91,90,21 }^odUIj  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9r
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        TextBox 220,49,40,21,.TextBox2 'default: 4 6s
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    End Dialog A*]sN8  
    Dim dlg As UserDialog ojIGfQV  
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    ok = Dialog (dlg) <hgfgk7<  
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    If ok=0 Then    'cancel button was pressed "p>kiNu  
        Print "Execution cancelled." uF D  
        End hb)8
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    End If rZRTQ  
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    'Assign accommodation and pupil diameter & use defaults if field left empty iE ,"YCK  
    If dlg.TextBox1 = "" Then 99~-TiU  
        A = 0           'Default accommodation ,v9*|>4  
    Else g- INhzMu  
        A = CDbl(dlg.TextBox1) qUQP.4Z95  
    End If 6\QsK96_  
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    If dlg.TextBox2 = "" Then eFQz G+/  
        pupilDiam = 4   'Default pupil diameter wu}Z
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    Else AC?a:{./  
        pupilDiam = CDbl(dlg.TextBox2) j#H&~f  
    End If Y)AHM0;g  
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    Print " " [F,s=,S'M  
    Print "Accommodation = " & A & " Diopters" E@Yq2FBpnn  
    Print "Pupil Diameter = " & pupilDiam & " mm" 'f7s*VKG  
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    ' Calculate new parameters with accommodation EPEn"{;U  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness `2G%&R,k"D  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens fQ2U|  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens &w^:nVgl  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens nc#} \  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens pEG!j ~  
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    tlens = 3.767 + 0.04*A                  'Lens thickness xl(R|D))  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction S$GWY^5}{  
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    'Adjust parameters to account for accommodation /jn0Xh  
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    '************************************************************************* ~8lB#NuN  
    'Aqueous thickness (Position of Lens) t8~isuiK  
    '************************************************************************* hx}X=7w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0P4g6t}e  
    GetCustomElement eID, entity 6eK7Jv\K  
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    parID = FindFullName( "Geometry.Arizona Eye" ) lMjeq.5nP  
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    ' Delete any shift(s) in z gt(!I^LHYc  
    count = 0 A4TW`g_zm  
    While GetOperationCount(eID)>count >ZnnGX6$(  
        GetOperation eID, count, op #sf1,k5'  
        If op.Type="ShiftZ" Then BIjkW.uf  
            DeleteOperation eID,count FBA th !E  
            count=count-1 "Q1oSpF  
        End If /+
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        count=count+1 GrM`\MIO  
    Wend S@WT;Q2Z  
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    'Set new shift in Ap
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    op.Type = "ShiftZ" *V@t]d$=#  
    op.val1 = taq %Lfy!]Ru  
    op.parent = parID @`rC2-V  
    AddOperation eID, op mFuHZ)iQG  
    Print "Set aqueous humor thickness = " & taq-0.55 ?; tz  
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    '************************************************************************* -N1X=4/fg  
    'Radius and conic constant of anterior lens ,y[w`Q\  
    '************************************************************************* O _^Y*!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) e
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    GetConic eID, entity, curv, conic qfgw^2aUa  
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    SetConic eID, entity, 1/Rant, CCant U%aDkC+M  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant j k/-7
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    '************************************************************************* i$XT Qr0K=  
    'Radius and conic constant of posterior lens b'(Hwc\ t  
    '************************************************************************* `s_k+ g  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) c/-PEsk_TP  
    GetConic eID, entity, curv, conic 1,pPLc(  
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    SetConic eID, entity, 1/Rpost, CCpost 6=jL2cqx  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Lz`_&&6  
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    '************************************************************************* (iu IeJ^Z  
    'Lens thickness (Position of posterior lens surface) ,TQ;DxB}=E  
    '************************************************************************* A=BT2j'l)  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) }_9yemP  
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    ' Delete any z-shift(s) VI8/@A1Gv  
    count = 0 .;%`I  
    While GetOperationCount(eID)>count E5t /-
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        GetOperation eID, count, op *30T$_PiX|  
        If op.Type="ShiftZ" Then 2%~+c|TH.)  
            DeleteOperation eID,count wRe2sjM  
            count=count-1 JYa3xeC;  
        End If d+&w7/F  
        count=count+1 (bGk=q=M  
    Wend WTu1t]  

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    'Set new z-shift eZmwF@  
    op.Type = "ShiftZ" r.v.y[u  
    op.val1 = tlens 3F{R$M}  
    op.parent = parID >$;,1N $bd  
    AddOperation eID, op 9]^NAlno  
    Print "Set lens thickness = " & tlens D]+@pKb  
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    '************************************************************************* v)LSH;<  
    'Lens index of refraction Q`z2SYz>  
    '************************************************************************* ~f?brQ?  
    eID = FindMaterial( "Lens" ) <l$ vnq  
    GetModelMaterial eID, mat w,;ox2  
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    mat.Nd = nlens QTjnXg?Ri  
    SetModelMaterial eID, mat 9Q&]5|x  
    Print "Set lens index of refraction = " & nlens /Ca M(^W   
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    '************************************************************************* \}; 4rm}V  
    'Pupil diameter ;H"OZRQ  
    '************************************************************************* \N)!]jq  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 9oj0X>| 1  
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    'Adjust pupil diameter (trimming volume inner hole) ]t_ Wl1*|  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Fuo.8  
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    ' Adjust pupil location to just in front of the lens fTd":F  
    parID = FindFullName( "Geometry.Arizona Eye" ) HK`r9frn  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Kj#h9e  
    count = 0 Eg$Er*)h8  
    While GetOperationCount(eID)>count /D;cm  
        GetOperation eID, count, op %WtF\p  
        If op.Type="ShiftZ" Then `i6q\-12n  
            DeleteOperation eID,count #QiNSS  
            count=count-1 &IkHP/  
        End If \d QRQL{LL  
        count=count+1 )?k~E=&o  
    Wend #kAk d-QY6  
    op.Type = "ShiftZ" bJFqyK:6  
    op.val1 = taq-0.01 gTg[!}_;\N  
    op.parent = parID 5 $.az  
    AddOperation eID, op K9S(Xip  
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    Print "Set pupil diameter = " & pupilDiam ^*WO*f>y  
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    'Update AZ Eye subassembly Description 0t)5KO  
    eID = FindFullName( "Geometry.Arizona Eye" ) j]6YLM@5$  
    GetEntity eID, entity z<8WN[fB  
    entity.Description = "Accommodation = " & A & "D" 10m`LG  
    SetEntity eID, entity CjLiLB  
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    Update [V41 Gk  
    Print "DONE!" *.+N?%sAP)  
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End Sub 2.&%mSN  
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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： sh}eKwh  
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Accommodation = 4 Diopters lt#3&@<v  
Pupil Diameter = 4 mm G[Jz(/yNH  
Set aqueous humor thickness = 2.81 R5fZ}C7  
Set anterior lens radius = 10.4 and conic constant = -2.375869 _sF Ad`  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 cfPQcB>A  
Set lens thickness = 3.927 r\m2Oo)]  
Set lens index of refraction = 1.42672 HLl"=m1/>  
Set pupil diameter = 4 g3\13<  
DONE! # 0/,teJk