[技术]Arizona眼睛模型 [复制链接]

简介 e<gx~N9l'  
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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@FsLHn  
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模型 EEf ]u7  
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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。 Sav`%0q?7a  
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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. Zzd/K^gg  
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光源 3/M.0}e  
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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。 :h";c"  
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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。 e-D4'lu  
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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。 Na!za'qk[o  
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视网膜的散射 WBppKj_M  
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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。 m=&j@  
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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。 [wcA.g*F  
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脚本 {tzxA_  
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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： <]#o*_aFP  
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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。 I5pp "*u  
余下的脚本计算与屈光度有关的所有参数。 P%GkcV  
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分析 zv%J=N$G
 
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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。 J@bW^>g*6u  
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脚本代码 _.f@Y`4d  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Hhf72IX  
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Dim entity As T_ENTITY OJ[rj`wrW^  
Dim op As T_OPERATION dM|g`rr E  
Dim mat As T_MODELMATERIAL :`<psvd  
Dim A As Double FX 1C e  
Dim pupilDiam As Double  <qn,  
Dim eID As Long mmN|F
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Dim parID As Long tP]q4i
 
Dim count As Integer |a(Q4 e/,  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 4[
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Dim tlens As Double, nlens As Double |e"/Mf[  
Dim curv As Double, conic As Double !"(u_dFw  
Dim ok As Long DNho%Xk  
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Sub Main J8h7e}n?  
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    '用户输入对话框 *SGlqR['\e  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 >x?2Fz.  
        TextBox 220,21,40,21,.TextBox1 'default: 0 {h^c  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 BQU/QoDY  
        OKButton 40,91,90,21 j1Fw U  
        CancelButton 190,91,90,21 fIEw(k<*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {*__B} ,N  
        TextBox 220,49,40,21,.TextBox2 'default: 4 T/7vM6u  
    End Dialog 3jg'1^c  
    Dim dlg As UserDialog x)\V lR  
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    ok = Dialog (dlg) 4f  jC  
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    If ok=0 Then    'cancel button was pressed w7ZG oh(  
        Print "Execution cancelled." zkG>u,B}  
        End ??+:vai2  
    End If 5l&jPk!=  
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    'Assign accommodation and pupil diameter & use defaults if field left empty
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    If dlg.TextBox1 = "" Then Z*h ;e;  
        A = 0           'Default accommodation .S6ji~;r  
    Else #jgqkMOd,j  
        A = CDbl(dlg.TextBox1) -XLo0  
    End If -4%]QS  
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    If dlg.TextBox2 = "" Then DOT=U _  
        pupilDiam = 4   'Default pupil diameter v<+4BjV!J}  
    Else :r^klJ(m  
        pupilDiam = CDbl(dlg.TextBox2) ?to1rFrU  
    End If ;fkSrdj  
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    Print " " #hZQ>zcF  
    Print "Accommodation = " & A & " Diopters" .5^a;`-+  
    Print "Pupil Diameter = " & pupilDiam & " mm" 3~:0?Zuq  
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    ' Calculate new parameters with accommodation QK'`=MU  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness kLq(!Gs  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens >KKeV(Ur  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens v*vn<nPAQ>  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens tw-fAMwU  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ia'x]
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    tlens = 3.767 + 0.04*A                  'Lens thickness k=ts&9\  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction =hPG_4#  
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    'Adjust parameters to account for accommodation "I@v&(Am;  
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    '************************************************************************* RA}U#D:$i  
    'Aqueous thickness (Position of Lens) NWb} OXK/  
    '************************************************************************* Y+5"uq<'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZWFG?8lJ  
    GetCustomElement eID, entity f.J9) lfb  
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    parID = FindFullName( "Geometry.Arizona Eye" ) })KJ60B  
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    ' Delete any shift(s) in z ,%[LwmET  
    count = 0 ) b
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    While GetOperationCount(eID)>count mF}c- D  
        GetOperation eID, count, op Z@}sCZ=#A  
        If op.Type="ShiftZ" Then 6NzBpur 2H  
            DeleteOperation eID,count 'YBi5_  
            count=count-1 3IGCl w(  
        End If (=`Z0)=  
        count=count+1 Z(KmS(  
    Wend c%ZeX%p  
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    'Set new shift in IF5sqv  
    op.Type = "ShiftZ" Ap%d<\,Z  
    op.val1 = taq Hw
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    op.parent = parID <{E;s)hD?  
    AddOperation eID, op Q! Kn|mnN  
    Print "Set aqueous humor thickness = " & taq-0.55 ax4*xxU  
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    '************************************************************************* xLe =d|6  
    'Radius and conic constant of anterior lens |3S'8OeCI  
    '************************************************************************* Z
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) "\4]X"3<+  
    GetConic eID, entity, curv, conic ~
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    SetConic eID, entity, 1/Rant, CCant kxygf9I!;  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant V_Xy2<V  
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    '************************************************************************* >vHH  
    'Radius and conic constant of posterior lens T_uNF8Bh  
    '************************************************************************* zpbcmQB*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ]}p2Tp;1  
    GetConic eID, entity, curv, conic ^I@ey*$  
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    SetConic eID, entity, 1/Rpost, CCpost ,c@r` x  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _t$lcOT  
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    '************************************************************************* 1a5?)D  
    'Lens thickness (Position of posterior lens surface) 03~+-h&n  
    '************************************************************************* Ok*VQKyDLH  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /z/hUa  
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    ' Delete any z-shift(s) Km[]^;6  
    count = 0 ?UxG/]",  
    While GetOperationCount(eID)>count GEhdk]<a7  
        GetOperation eID, count, op \H,V 9!B  
        If op.Type="ShiftZ" Then ^?E^']H)5u  
            DeleteOperation eID,count _2]e1_=  
            count=count-1 g!p+rq_f  
        End If c zZrP"  
        count=count+1 <+<)xwOQ ]  
    Wend 2ZU@>W  
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    'Set new z-shift &
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    op.Type = "ShiftZ" $/4Wod*l  
    op.val1 = tlens mw:3q6  
    op.parent = parID v>JB rIb$  
    AddOperation eID, op uOyLC<I/  
    Print "Set lens thickness = " & tlens )EhTM-1  
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    '************************************************************************* ' %bj9{(0  
    'Lens index of refraction d8xk&za  
    '************************************************************************* UeMnc 5y  
    eID = FindMaterial( "Lens" ) F(T=WR].o  
    GetModelMaterial eID, mat 9c"0~7v  
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    mat.Nd = nlens F?}m8ZRv  
    SetModelMaterial eID, mat d [\>'>  
    Print "Set lens index of refraction = " & nlens B$K7L'e+-  
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    '************************************************************************* @).WIs  
    'Pupil diameter o@qN#Mg?>}  
    '************************************************************************* ]+}:VaeA  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ],BJ}~v,X  
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    'Adjust pupil diameter (trimming volume inner hole) o%kSR ]V|  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _DNkdS [[  
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    ' Adjust pupil location to just in front of the lens [{6&.v  
    parID = FindFullName( "Geometry.Arizona Eye" ) PiIp<fJd$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) b|X>3(  
    count = 0 d_4n0Kh0  
    While GetOperationCount(eID)>count t:?<0yfp&  
        GetOperation eID, count, op 9`LU=Xv/  
        If op.Type="ShiftZ" Then 8r7/IGFg  
            DeleteOperation eID,count f9h:"Dnzin  
            count=count-1 8.Pcr<  
        End If {q5hF5!`)  
        count=count+1 Y;a6:>D%cT  
    Wend x]yHBc  
    op.Type = "ShiftZ" #J%h!#3g  
    op.val1 = taq-0.01 dg!1wD  
    op.parent = parID X+(aQ >y  
    AddOperation eID, op HB/ _O22  
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    Print "Set pupil diameter = " & pupilDiam `^s]?  
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    'Update AZ Eye subassembly Description !Szgph"ul  
    eID = FindFullName( "Geometry.Arizona Eye" ) x9XGCr  
    GetEntity eID, entity ~Mg8C9B?%3  
    entity.Description = "Accommodation = " & A & "D" @B>%B EC  
    SetEntity eID, entity puf;"c6e'  
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    Update 4wM$5  
    Print "DONE!" [T$$od[.  
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End Sub ?z4uze1  
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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： K'{wncumQ  
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Accommodation = 4 Diopters erAZG)  
Pupil Diameter = 4 mm &9jUf:gJ0  
Set aqueous humor thickness = 2.81 B?/12+sR  
Set anterior lens radius = 10.4 and conic constant = -2.375869 EF_h::A_  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 z-{"pI  
Set lens thickness = 3.927 ?j^?@%f0  
Set lens index of refraction = 1.42672 gZ79u  
Set pupil diameter = 4 Og%zf1)aZM  
DONE! n WO~v{h3J