[技术]Arizona眼睛模型 [复制链接]

简介 ^5n#hSqZ=M  
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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*h3U@5#K  
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模型 v83@J~  
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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。 {WvYb,
  
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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. *_sSM+S  
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光源 \gFV6 H?`  
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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。 _-|+k  
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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。 #+Y%Bxf  
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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=>^ 8[0O  
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视网膜的散射 D]twid~OS  
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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。 {8"Uxj_6V  
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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。 TDX~?>P  
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脚本 +E']&v$  
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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： ^"iJ  
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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。 K!
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余下的脚本计算与屈光度有关的所有参数。 tB`IBuy9!"  
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分析 '=(D7F;  
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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。 BP@V:z  
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脚本代码 A{Qo}F<*  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. |S]T,`7u  
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Dim entity As T_ENTITY QT=i>X  
Dim op As T_OPERATION 4|UtE<<b  
Dim mat As T_MODELMATERIAL K j~!E H"  
Dim A As Double b3ys
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Dim pupilDiam As Double  `7oYXk  
Dim eID As Long 4KR$sKq$q  
Dim parID As Long d4)0G-|  
Dim count As Integer "5v^6R9e  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double L
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Dim tlens As Double, nlens As Double o1k+dJUd  
Dim curv As Double, conic As Double })j N 8px  
Dim ok As Long >`<qa!9  
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Sub Main U,lO{J
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    '用户输入对话框 y(O~=S+<  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 /4}y2JVv)  
        TextBox 220,21,40,21,.TextBox1 'default: 0 kG5Uc83#G  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^\r{72!y  
        OKButton 40,91,90,21 R5\|pC  
        CancelButton 190,91,90,21 @+a}O  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 _YN C}PUU  
        TextBox 220,49,40,21,.TextBox2 'default: 4 (C.aQ)|T  
    End Dialog ^O}J',Fm%f  
    Dim dlg As UserDialog Cq[Hh#q  
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    ok = Dialog (dlg)  &_-3>8gU  
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    If ok=0 Then    'cancel button was pressed h+S]C#X,}  
        Print "Execution cancelled." "N)InPR-  
        End >Bu_NoM  
    End If Lt i2KY}/%  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ZG?e%  
    If dlg.TextBox1 = "" Then ],{M``]q  
        A = 0           'Default accommodation Y~w1_>b  
    Else +O)ZB$w4  
        A = CDbl(dlg.TextBox1) PS0/Ok  
    End If EKS?3z%!  
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    If dlg.TextBox2 = "" Then P76gJ@#m  
        pupilDiam = 4   'Default pupil diameter >qUD_U3A  
    Else "rVM23@ tq  
        pupilDiam = CDbl(dlg.TextBox2) &*oljGt8  
    End If k5*Z@a  
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    Print " " SjIDzNI5  
    Print "Accommodation = " & A & " Diopters" I}m>t}QRI_  
    Print "Pupil Diameter = " & pupilDiam & " mm" `R!2N4|;  
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    ' Calculate new parameters with accommodation nU0##  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Qz"//=hC|H  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Kjpsz];  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens tgHN\@yj  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens T!Lv%i*|Y  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens xk3)#*  
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    tlens = 3.767 + 0.04*A                  'Lens thickness }:[MSUm5  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction >FJK$>[1:p  
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    'Adjust parameters to account for accommodation SR`A]EC(V  
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    '************************************************************************* &Aym@G|k?  
    'Aqueous thickness (Position of Lens) AP8J28I  
    '************************************************************************* 54/ZGaonz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (cI@#x  
    GetCustomElement eID, entity Cv/3-&5S  
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    parID = FindFullName( "Geometry.Arizona Eye" ) OAEa+V
 
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    ' Delete any shift(s) in z
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    count = 0 LX #.  
    While GetOperationCount(eID)>count \&U"7gSL  
        GetOperation eID, count, op dj}P|v/;z  
        If op.Type="ShiftZ" Then $$*0bRfd4=  
            DeleteOperation eID,count K6
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            count=count-1 NE3/>5  
        End If W .Al\!Gi  
        count=count+1 Ik@MIxLK  
    Wend %o`Cp64`Q  
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    'Set new shift in ~q}]/0-m  
    op.Type = "ShiftZ" Ri}JM3\J  
    op.val1 = taq }:1qK67S  
    op.parent = parID Vg mYm~y'  
    AddOperation eID, op 9WHarv2@  
    Print "Set aqueous humor thickness = " & taq-0.55 /b6
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    '************************************************************************* wy:euKB~   
    'Radius and conic constant of anterior lens w(ic$  
    '************************************************************************* fSGaUBiq}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Eh[NKgYL  
    GetConic eID, entity, curv, conic &yqk96z  
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    SetConic eID, entity, 1/Rant, CCant =,&{ &m)  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant v[a4d&P  
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    '************************************************************************* akwS;|SZ  
    'Radius and conic constant of posterior lens 6^FUu
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    '************************************************************************* "L9pFz</  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 9Z3Vf[n5\  
    GetConic eID, entity, curv, conic JqEo~]E]  
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    SetConic eID, entity, 1/Rpost, CCpost zCu+Oi6  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 6']WOM#  
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    '************************************************************************* ytV4qU82G  
    'Lens thickness (Position of posterior lens surface) (D\`:
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    '************************************************************************* 5rJ7CfVq  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" )
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    ' Delete any z-shift(s) C4|79UG>s  
    count = 0 j'UWgwB  
    While GetOperationCount(eID)>count !{ORFd  
        GetOperation eID, count, op 9v7}[`^  
        If op.Type="ShiftZ" Then cWI7];/d;  
            DeleteOperation eID,count Cn>t"#zs!~  
            count=count-1 :r&4/sN}<  
        End If c2d1'l]n  
        count=count+1 ETfoL.d$(  
    Wend xI~c~KC  
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    'Set new z-shift `<% w4E  
    op.Type = "ShiftZ" ,LL=b-Es  
    op.val1 = tlens jW}hLjlN  
    op.parent = parID [Fr <tKtB  
    AddOperation eID, op qc6d,z/  
    Print "Set lens thickness = " & tlens ^5-SL?E  
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    '*************************************************************************
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    'Lens index of refraction 0EC/l OS  
    '************************************************************************* yeV|j\TJI.  
    eID = FindMaterial( "Lens" ) /qd~|[Kx:  
    GetModelMaterial eID, mat P>7PO~E
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    mat.Nd = nlens "}<baz  
    SetModelMaterial eID, mat s6I/%R3  
    Print "Set lens index of refraction = " & nlens =8DS~J{  
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    '************************************************************************* nB%[\LtZ
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    'Pupil diameter ~B`H5#  
    '************************************************************************* Lx3`.F\m
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 7#9fcfL  
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    'Adjust pupil diameter (trimming volume inner hole) *(nu0  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" s18A  
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    ' Adjust pupil location to just in front of the lens Qs_]U  
    parID = FindFullName( "Geometry.Arizona Eye" ) IZZ $p{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) gE6{R+sp  
    count = 0 #LG<o3An  
    While GetOperationCount(eID)>count A)nE+ec1  
        GetOperation eID, count, op !GoHCe[10  
        If op.Type="ShiftZ" Then {)-3g~  
            DeleteOperation eID,count w#;y  
            count=count-1 GUsJF;
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        End If zHvW@A'F  
        count=count+1 M =GF@C;b  
    Wend `W4Is~VVv  
    op.Type = "ShiftZ" Q7?[@2HN  
    op.val1 = taq-0.01 aOW$H:b  
    op.parent = parID ;7g~4Uv4}  
    AddOperation eID, op >):>Pz%U  
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    Print "Set pupil diameter = " & pupilDiam e]smnf  
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    'Update AZ Eye subassembly Description s%)>O{{)  
    eID = FindFullName( "Geometry.Arizona Eye" ) <GoZ>  
    GetEntity eID, entity nkz^^q`5l7  
    entity.Description = "Accommodation = " & A & "D" m?`$NJST  
    SetEntity eID, entity p4lB#  
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    Update D;X/7 p|>  
    Print "DONE!" NQ\<~a`Eq  
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End Sub Y!_e,]GW  
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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： ]U3@V#*  
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Accommodation = 4 Diopters @5TJ]=  
Pupil Diameter = 4 mm ef -PlGn  
Set aqueous humor thickness = 2.81 bcFZ~B  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ?rgtbiSW-  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 +v|]RgyW)  
Set lens thickness = 3.927 `HsI)RmX  
Set lens index of refraction = 1.42672 A)u,Hvn  
Set pupil diameter = 4 bH_zWk  
DONE! Y/G~P,9