[技术]Arizona眼睛模型 [复制链接]

简介 KO/Z|I  
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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。  )z#  
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模型 =jZ}@L/+  
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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。 &t1?=F,]  
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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. |f+|OZY  
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光源 h6c0BmS{1  
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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。 (bnyT?p%  
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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。 [>l
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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。 63R?=u@  
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视网膜的散射 04{*iS95J  
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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。 +RLHe]9&  
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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。 #P[d?pY  
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脚本 a(>oQG8F  
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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： V2-fJ!  
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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。 8%-+@\=  
余下的脚本计算与屈光度有关的所有参数。 \va'>?#o1  
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分析 C4vmgl&  
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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。 |#hj O3  
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脚本代码 )*j>g38?  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. t+C9QXY  
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Dim entity As T_ENTITY <Z^P8nu  
Dim op As T_OPERATION Q4;
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Dim mat As T_MODELMATERIAL 70s.  
Dim A As Double %6-5hBzZN  
Dim pupilDiam As Double 3{wr*L1%-~  
Dim eID As Long "VEA71  
Dim parID As Long
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Dim count As Integer L< 3U)Gp  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ""LCyKu   
Dim tlens As Double, nlens As Double U;%I" p`Z/  
Dim curv As Double, conic As Double D|zlC,J,  
Dim ok As Long @KtQ~D  
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Sub Main WO=X*One  
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    '用户输入对话框 $F> #1:=v<  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 <A
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        TextBox 220,21,40,21,.TextBox1 'default: 0 ldEZ_g^  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 hEG-,   
        OKButton 40,91,90,21 |g o jb  
        CancelButton 190,91,90,21  U~%V;*|4  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 >GRL5Iow  
        TextBox 220,49,40,21,.TextBox2 'default: 4 (?luV#{5  
    End Dialog p72:oX\QI  
    Dim dlg As UserDialog /{|<3CEe  
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    ok = Dialog (dlg) 2?=R_&0Q  
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    If ok=0 Then    'cancel button was pressed Iud]*5W  
        Print "Execution cancelled." vn5X]U"  
        End M6$9-  
    End If R~9\mi5^UH  
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    'Assign accommodation and pupil diameter & use defaults if field left empty l# -4}95  
    If dlg.TextBox1 = "" Then )HLe8:PG~  
        A = 0           'Default accommodation y,I?3p|S  
    Else g[Tl#X7F  
        A = CDbl(dlg.TextBox1) m@Ziif-A  
    End If 3$cIm+  
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    If dlg.TextBox2 = "" Then Qi&!Ub]  
        pupilDiam = 4   'Default pupil diameter \W"N{N  
    Else K6vF}A|  
        pupilDiam = CDbl(dlg.TextBox2) x2@Q5|a  
    End If K|Q|v39{b  
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    Print " " wI\ n%#  
    Print "Accommodation = " & A & " Diopters" p([g/Q  
    Print "Pupil Diameter = " & pupilDiam & " mm" BU\P5uB!V  
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    ' Calculate new parameters with accommodation %}t<,ex(yO  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {Q/XV=  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens dE0 `tX  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ]QB<N|ps  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens yJ(BPSt  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ze%kP#c6!  
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    tlens = 3.767 + 0.04*A                  'Lens thickness qu}`;\9@ld  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {J`]6ba  
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    'Adjust parameters to account for accommodation p&Os5zw;|  
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    '************************************************************************* BvXA9YQ3  
    'Aqueous thickness (Position of Lens) Equj[yw%@  
    '************************************************************************* };rxpw>ms  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) O26'|w@$  
    GetCustomElement eID, entity u`%Kh_  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Ek0zFnb[Gx  
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    ' Delete any shift(s) in z vr/O%mD
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    count = 0 D..dGh.MY  
    While GetOperationCount(eID)>count _$wXHONt  
        GetOperation eID, count, op ?Cg",k'  
        If op.Type="ShiftZ" Then jm|x=s3}h  
            DeleteOperation eID,count =qQH,{]c6  
            count=count-1 {km~,]N
  
        End If QkEIV<T&)l  
        count=count+1 'N-nFc^  
    Wend 5>E]C=maD  
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    'Set new shift in d0@&2hO  
    op.Type = "ShiftZ" J%_m`?  
    op.val1 = taq '<
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    op.parent = parID >8I?YT.  
    AddOperation eID, op ~EYsUC#B_  
    Print "Set aqueous humor thickness = " & taq-0.55 !B&OK&*  
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    '************************************************************************* QD<GXPu?N  
    'Radius and conic constant of anterior lens *]L(,_:"  
    '************************************************************************* V^n?0^o  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) J}$St|1y  
    GetConic eID, entity, curv, conic wt8?@lJ"/  
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    SetConic eID, entity, 1/Rant, CCant v)^8e0vx  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant byT@O:fL  
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    '************************************************************************* Y|*a,H"_  
    'Radius and conic constant of posterior lens aan)yP  
    '************************************************************************* aP#nK  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) q_5hKipd\b  
    GetConic eID, entity, curv, conic 7W)*IJ  
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    SetConic eID, entity, 1/Rpost, CCpost V30Om3C  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost D*!UB5<>/t  
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    '************************************************************************* s)gUvS\  
    'Lens thickness (Position of posterior lens surface) G*oqhep  
    '************************************************************************* %K9 9_Cl3  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 91|0{
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    ' Delete any z-shift(s) yvQRr75
  
    count = 0 vz\^Aa #fv  
    While GetOperationCount(eID)>count hd~3I4D  
        GetOperation eID, count, op 5,i0QT"  
        If op.Type="ShiftZ" Then kYwV
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            DeleteOperation eID,count vpnOc2 -  
            count=count-1 1FkS$ j8:  
        End If ~
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        count=count+1 M,uQ8SZA[  
    Wend !=-{$& {  
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    'Set new z-shift /t4#-vz  
    op.Type = "ShiftZ" ZxDh94w/  
    op.val1 = tlens X(YR).a~  
    op.parent = parID 1N3qMm^  
    AddOperation eID, op w=|"{-ijo  
    Print "Set lens thickness = " & tlens j'2:z#  
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    '************************************************************************* vXq2="+  
    'Lens index of refraction j9voeV|7  
    '************************************************************************* %^zGM^PD  
    eID = FindMaterial( "Lens" ) B&bQvdp  
    GetModelMaterial eID, mat 4s <|8  
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    mat.Nd = nlens ZQ MK1  
    SetModelMaterial eID, mat L/39<&W  
    Print "Set lens index of refraction = " & nlens l-~ o&n  
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    '************************************************************************* h#e((j3-2Z  
    'Pupil diameter x/)o'#d$|l  
    '************************************************************************* <kc9KE  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) kuQ+MQHs  
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    'Adjust pupil diameter (trimming volume inner hole) 4ayZ.`aK  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 3|Vh[iAa\  
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    ' Adjust pupil location to just in front of the lens P {8d.  
    parID = FindFullName( "Geometry.Arizona Eye" ) *# 7 1aZ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) %F.^cd"  
    count = 0 axpn*
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    While GetOperationCount(eID)>count %]KOxaf_z  
        GetOperation eID, count, op It@1!_tO2  
        If op.Type="ShiftZ" Then x&['g*[L0  
            DeleteOperation eID,count  4u.v7r  
            count=count-1 ?h1r6?Sug{  
        End If !#b8QER  
        count=count+1 W
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    Wend 0|L%)'F  
    op.Type = "ShiftZ" Iu=n$H  
    op.val1 = taq-0.01 ~4}'R_  
    op.parent = parID Wh7}G   
    AddOperation eID, op 8s@k0T<O  
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    Print "Set pupil diameter = " & pupilDiam |s}7<A  
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    'Update AZ Eye subassembly Description k04CSzE"%  
    eID = FindFullName( "Geometry.Arizona Eye" ) @/yQ4Gr  
    GetEntity eID, entity o;^k"bo6  
    entity.Description = "Accommodation = " & A & "D" FTk`Mq  
    SetEntity eID, entity 920 o]Dh=t  
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    Update \0'0)@uziQ  
    Print "DONE!" ky^u.+cZ  
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End Sub /z(;1$Ld6{  
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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： C3#mmiL-  
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Accommodation = 4 Diopters !#'
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Pupil Diameter = 4 mm rO;Vr},3\%  
Set aqueous humor thickness = 2.81 :}[RDF?  
Set anterior lens radius = 10.4 and conic constant = -2.375869 'U%L\v,  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 +o*&JoC  
Set lens thickness = 3.927 V+yyy-/  
Set lens index of refraction = 1.42672 o$[alh;c+W  
Set pupil diameter = 4 Ga9^+.j  
DONE! rf[w&~R