[技术]Arizona眼睛模型 [复制链接]

简介 ]QT0sGl  
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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。 cfeX(0  
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模型 U-FA^c;  
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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。 3^Yk?kFE  
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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. RaU.yCYyu  
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光源 q<yH!  
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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。 R\.huOJh  
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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。 3(5RUI-  
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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。 J.<%E[ z  
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视网膜的散射 L|q<Bpz  
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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。 /XSPVc<  
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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。 QhGg^h%6  
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脚本 li%-9Jd  
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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： &1h3o^K  
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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。 vR)7qX}  
余下的脚本计算与屈光度有关的所有参数。 \9}5}X_x.  
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分析 %7d"()L  
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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。 7k\7G=  
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脚本代码 vLS9V/o  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. DrEtnt  
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Dim entity As T_ENTITY s =5H.q%PV  
Dim op As T_OPERATION P\s+2/  
Dim mat As T_MODELMATERIAL W<LaR,7  
Dim A As Double _Y|kX2l S@  
Dim pupilDiam As Double {@#L'i|  
Dim eID As Long 84!4Vz^  
Dim parID As Long ? g{,MP5  
Dim count As Integer vQ/\BN  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^<VE5OM  
Dim tlens As Double, nlens As Double ziycyf.d  
Dim curv As Double, conic As Double DXz8C -  
Dim ok As Long spx;QLo  
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Sub Main X}-H=1T?  
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    '用户输入对话框 |+:ZO5FaO  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2A%T!9J3  
        TextBox 220,21,40,21,.TextBox1 'default: 0 5 WppV3;  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 kVrT?  
        OKButton 40,91,90,21 GF!{SO4  
        CancelButton 190,91,90,21 v,+l xY  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 W[>TqT63  
        TextBox 220,49,40,21,.TextBox2 'default: 4 7h]R{_  
    End Dialog a1`cI5
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    Dim dlg As UserDialog nh=Us^xD  
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    ok = Dialog (dlg) L||yQH7n  
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    If ok=0 Then    'cancel button was pressed is?&%VY  
        Print "Execution cancelled." R$fIb}PDr  
        End r65
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    End If D:ugP,  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Kg`x9._2  
    If dlg.TextBox1 = "" Then I
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        A = 0           'Default accommodation %B&?D@  
    Else +@uC:3jM  
        A = CDbl(dlg.TextBox1) HCIF9{o1j>  
    End If /Z " 4[  
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    If dlg.TextBox2 = "" Then :J`!'{r  
        pupilDiam = 4   'Default pupil diameter I!7.fuO  
    Else A]?O&m|  
        pupilDiam = CDbl(dlg.TextBox2) _ 1{5~  
    End If z83:a)U  
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    Print " " z#J/*712  
    Print "Accommodation = " & A & " Diopters" f5b`gvCY,#  
    Print "Pupil Diameter = " & pupilDiam & " mm" O4PdN?  
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    ' Calculate new parameters with accommodation N^yO- xk  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness UVCMB_T  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens /^33 e+j  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens <oaBh)=7  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ls"\YSq$  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ?*R^?[  
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    tlens = 3.767 + 0.04*A                  'Lens thickness aho<w+l@  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 9h38`*Im;  
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    'Adjust parameters to account for accommodation e=]oh$]  
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    '************************************************************************* _IKP{WNB  
    'Aqueous thickness (Position of Lens) 9Oo*8wvGG  
    '************************************************************************* ]b~2Dap  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?J@?,rZQ^V  
    GetCustomElement eID, entity 88np/jvC{  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 9 /Ai(  
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    ' Delete any shift(s) in z X\^& nLa  
    count = 0 0o=6A<#x  
    While GetOperationCount(eID)>count a,57`Ks+n<  
        GetOperation eID, count, op zUEfa!#?  
        If op.Type="ShiftZ" Then R#7+  
            DeleteOperation eID,count (LT\ IJSM  
            count=count-1 @Uj_+c q  
        End If x:n9dm  
        count=count+1 ;[OJ-|Q  
    Wend jRdhLs,M9  
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    'Set new shift in hKH$AEHEU}  
    op.Type = "ShiftZ" ^0-e,d 9h  
    op.val1 = taq
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    op.parent = parID 4j@kMe;RjZ  
    AddOperation eID, op Dmm r]~  
    Print "Set aqueous humor thickness = " & taq-0.55 o9T@uWh+  
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    '************************************************************************* @RoRNat  
    'Radius and conic constant of anterior lens .i3lG( YG  
    '************************************************************************* <(bCz>o|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) *t?~)o7  
    GetConic eID, entity, curv, conic "x.6W!  
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    SetConic eID, entity, 1/Rant, CCant yYG3/Z3
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant zh{@?k  
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    '************************************************************************* |`k1zc)9  
    'Radius and conic constant of posterior lens p(H)WD  
    '************************************************************************* $||ns@F+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) y=oVUsG  
    GetConic eID, entity, curv, conic \=
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    SetConic eID, entity, 1/Rpost, CCpost w]W`R.  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 38w.sceaT  
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    '************************************************************************* ^EC)~HP@C  
    'Lens thickness (Position of posterior lens surface) ;e~{
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    '************************************************************************* }1a<{
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Y0Hq+7x  
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    ' Delete any z-shift(s) +3/k/W  
    count = 0 +gbX}jF0%  
    While GetOperationCount(eID)>count -TK|Y"  
        GetOperation eID, count, op &O+sK4P  
        If op.Type="ShiftZ" Then kW<Yda<a  
            DeleteOperation eID,count .Ca"$2  
            count=count-1 &J lpA<^s;  
        End If KdOh'OrT9.  
        count=count+1 H})Dcg3  
    Wend }@rg5$W  
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    'Set new z-shift \A'|XdQ  
    op.Type = "ShiftZ" (C-,ljY
 
    op.val1 = tlens z`emKFbv  
    op.parent = parID 97qtJ(ESI  
    AddOperation eID, op J{Y6fHFi  
    Print "Set lens thickness = " & tlens O8K@&V
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    '************************************************************************* >\|kJ?h  
    'Lens index of refraction Kcs
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    '************************************************************************* 18
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    eID = FindMaterial( "Lens" ) ~_DF06G  
    GetModelMaterial eID, mat Af2=qe  
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    mat.Nd = nlens rao</jN.9  
    SetModelMaterial eID, mat I! h(`  
    Print "Set lens index of refraction = " & nlens 7ei>L]gm%  
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    '************************************************************************* p{iG{  
    'Pupil diameter "rme~
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    '************************************************************************* l^DINZU@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =y)p>3p}&  
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    'Adjust pupil diameter (trimming volume inner hole) l,*yEkU  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" !1ML%}vvB,  
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    ' Adjust pupil location to just in front of the lens $x?NNS_ "J  
    parID = FindFullName( "Geometry.Arizona Eye" ) q*~gWn>T  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Uby,Tu  
    count = 0 A)\>#Dv  
    While GetOperationCount(eID)>count [8,PO  
        GetOperation eID, count, op H7{Q@D8  
        If op.Type="ShiftZ" Then |ZS 57c:  
            DeleteOperation eID,count YS]
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            count=count-1 5;X {.2  
        End If nqZA|-}  
        count=count+1 Hu<p?mF#  
    Wend 7IA3q{P  
    op.Type = "ShiftZ" m!rwG(  
    op.val1 = taq-0.01 /h/6&R0l  
    op.parent = parID Q Oz9\,C  
    AddOperation eID, op 3LKB;  
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    Print "Set pupil diameter = " & pupilDiam w+q?T  
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    'Update AZ Eye subassembly Description V
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    eID = FindFullName( "Geometry.Arizona Eye" ) ~}h^38  
    GetEntity eID, entity fJX\'Rc\  
    entity.Description = "Accommodation = " & A & "D" y)6,0K {k  
    SetEntity eID, entity ?Q@L-H`  
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    Update u FMIY(vB  
    Print "DONE!" *Wzwbwg  
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End Sub Iph3%
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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： ?$3r5sx  
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Accommodation = 4 Diopters Y5HfN[u^7  
Pupil Diameter = 4 mm (YIhTSL"]  
Set aqueous humor thickness = 2.81 {] O`gG  
Set anterior lens radius = 10.4 and conic constant = -2.375869 L{=l#vu  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 =K:(&6f<t  
Set lens thickness = 3.927 IeVLn^?+:  
Set lens index of refraction = 1.42672 J2r1=5HS  
Set pupil diameter = 4 *9J1$Wa  
DONE! tG/1p

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