[技术]Arizona眼睛模型 [复制链接]

简介 v=?2S  
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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。 PXk?aJ  
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模型 \6!W05[ Q  
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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。 <q2?S  
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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. l.+yn91%>  
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光源 BS1A
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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。 j\&pej  
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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。 gl%`qf6:O  
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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 Be7"^  
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视网膜的散射 s>n(`?@L  
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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。 Kg\R+i@#<  
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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。 ` uCIXb  
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脚本 V^s0fWa  
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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： )?! [}t  
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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。 [^YA=Khu  
余下的脚本计算与屈光度有关的所有参数。 SkQswH  
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分析 BqK(DH^9N  
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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。 m"eteA,"k_  
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脚本代码 O`1!  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. (.Y/  
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Dim entity As T_ENTITY I{'f|+1  
Dim op As T_OPERATION xgu `Q`~  
Dim mat As T_MODELMATERIAL >R,'5:Rw  
Dim A As Double I?#85l{>  
Dim pupilDiam As Double n"Veem[_4g  
Dim eID As Long Fh|#u:n  
Dim parID As Long ] ]U<UJ  
Dim count As Integer Bh`N[\r  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double PXoz*)tk  
Dim tlens As Double, nlens As Double X!hIwiA,t  
Dim curv As Double, conic As Double y;cUl, :v  
Dim ok As Long B_`y
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Sub Main hOv={:  
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    '用户输入对话框 Vgb *% I  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 (:V>Hjt  
        TextBox 220,21,40,21,.TextBox1 'default: 0 $q?$]k|M`  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 e1myH6$W  
        OKButton 40,91,90,21 Psura$:  
        CancelButton 190,91,90,21 p^kUs0$GS  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 6d[_G$'nk  
        TextBox 220,49,40,21,.TextBox2 'default: 4 620%Z*   
    End Dialog MB ju![n  
    Dim dlg As UserDialog bu7'oB~:V^  
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    ok = Dialog (dlg) 'nQVj  
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    If ok=0 Then    'cancel button was pressed n]_[NR) i  
        Print "Execution cancelled." 1LJuCI=~  
        End tY${M^^<J  
    End If `vG,}Pt]  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ,C.:;Ime({  
    If dlg.TextBox1 = "" Then @oF$LMD  
        A = 0           'Default accommodation  9fnA   
    Else ]?1Y e8>Y<  
        A = CDbl(dlg.TextBox1) o;a:Dd  
    End If cq&*.  
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    If dlg.TextBox2 = "" Then GDhE[of  
        pupilDiam = 4   'Default pupil diameter `i) 2nNJ"  
    Else mffn//QS  
        pupilDiam = CDbl(dlg.TextBox2) B&+`)E{KB  
    End If EFuvp
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    Print " " HmfG$Z  
    Print "Accommodation = " & A & " Diopters" 87%*+n:?*  
    Print "Pupil Diameter = " & pupilDiam & " mm" .#u_#=g?  
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    ' Calculate new parameters with accommodation |{*}|  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness OH^N" L  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens {qW~"z*  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens :WI.LKlo~  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Om'+]BBN  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens [ xOzzp4  
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    tlens = 3.767 + 0.04*A                  'Lens thickness cfox7FmW  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction P1b'%  
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    'Adjust parameters to account for accommodation 8zLY6@
  
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    '************************************************************************* M<SdPC(+  
    'Aqueous thickness (Position of Lens) i&njqK!wS  
    '************************************************************************* >&g}7d
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) )15Z#`x  
    GetCustomElement eID, entity f)c~cJz<q  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 4Wy<?O2  
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    ' Delete any shift(s) in z MS(JR  
    count = 0 ~^
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    While GetOperationCount(eID)>count [S.ZJUns  
        GetOperation eID, count, op 9jN)I(^D6  
        If op.Type="ShiftZ" Then nJRS.xs  
            DeleteOperation eID,count J$4wL F3  
            count=count-1 Tmh(= TB'  
        End If "G-1>:   
        count=count+1 'Y$R~e^Y?  
    Wend 9_\'LJ  
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    'Set new shift in :Ih|en^w  
    op.Type = "ShiftZ" A^ _a3$,0  
    op.val1 = taq ,D\GGRw  
    op.parent = parID %}86D[PF  
    AddOperation eID, op M3p   
    Print "Set aqueous humor thickness = " & taq-0.55 >FhK#*Pa  
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    '*************************************************************************
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    'Radius and conic constant of anterior lens WwC 5!kZ  
    '************************************************************************* UA[,2MBp  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) L,d LE
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    GetConic eID, entity, curv, conic 2&+#Vsm`V  
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    SetConic eID, entity, 1/Rant, CCant $^&ig  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant yCJFo  
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    '************************************************************************* t9&cE:n  
    'Radius and conic constant of posterior lens zkTp`>9R  
    '************************************************************************* #j@71]GI  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) /h v4x9  
    GetConic eID, entity, curv, conic h25G/`  
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    SetConic eID, entity, 1/Rpost, CCpost kc/{[ME  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost \%sVHt`c  
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    '************************************************************************* :K\mN/ x  
    'Lens thickness (Position of posterior lens surface) o!:8nXw  
    '************************************************************************* K1V#cB WO  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) A2}Rl%+X]6  
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    ' Delete any z-shift(s) <foCb%$(?  
    count = 0 0!z@2[Pe66  
    While GetOperationCount(eID)>count Bl9jkq ]  
        GetOperation eID, count, op qO`)F8  
        If op.Type="ShiftZ" Then +0),xu   
            DeleteOperation eID,count :V2bS  
            count=count-1 kNu'AT#3|  
        End If O]f/r,4@  
        count=count+1 D>
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    Wend \A
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    'Set new z-shift .I}:m%zv  
    op.Type = "ShiftZ" sH[ -W-  
    op.val1 = tlens _C\[DR0n  
    op.parent = parID /6O??6g  
    AddOperation eID, op yL
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    Print "Set lens thickness = " & tlens 56l@a{  
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    '************************************************************************* l!#m&'16"  
    'Lens index of refraction 86f2'o+  
    '************************************************************************* PSawMPw  
    eID = FindMaterial( "Lens" ) nA?Hxos  
    GetModelMaterial eID, mat L6>pGx  
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    mat.Nd = nlens 8A{_GH{:  
    SetModelMaterial eID, mat cI]WrI2CQa  
    Print "Set lens index of refraction = " & nlens eMRar<)+#*  
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    '************************************************************************* _2btfY1U  
    'Pupil diameter $,xnU.n  
    '************************************************************************* Sx
   
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) uP\lCqK,  
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    'Adjust pupil diameter (trimming volume inner hole) 2iu_pjj  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" &rDM<pO #-  
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    ' Adjust pupil location to just in front of the lens y/V%&.$o=  
    parID = FindFullName( "Geometry.Arizona Eye" ) g+-;J+X8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 7FN<iI&7\  
    count = 0 ,Ma.V\T[  
    While GetOperationCount(eID)>count 1Y_w5dU  
        GetOperation eID, count, op X0{/ydGF8  
        If op.Type="ShiftZ" Then WWT",gio  
            DeleteOperation eID,count c`x7u}C  
            count=count-1 Ax oD8|  
        End If H"2uxhdLK3  
        count=count+1 %LXM+<N8  
    Wend
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    op.Type = "ShiftZ" yGg,$WM  
    op.val1 = taq-0.01 DoC(Z)o  
    op.parent = parID
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    AddOperation eID, op )'l*Tl  
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    Print "Set pupil diameter = " & pupilDiam -st7_3  
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    'Update AZ Eye subassembly Description kF7(f|*  
    eID = FindFullName( "Geometry.Arizona Eye" ) Z -%(~  
    GetEntity eID, entity bbxLBD'  
    entity.Description = "Accommodation = " & A & "D" PiFD^w  
    SetEntity eID, entity E^w:KC2@  
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    Update R];Oxe  
    Print "DONE!" 1exl0]-  
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End Sub \yrisp#`  
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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： *9ywXm&?  

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Accommodation = 4 Diopters ch5s<x#CE  
Pupil Diameter = 4 mm j?b\+rr  
Set aqueous humor thickness = 2.81 3M5#4n\v$  
Set anterior lens radius = 10.4 and conic constant = -2.375869 L]a`"CH:a$  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 OT %nrzP  
Set lens thickness = 3.927 8#R
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Set lens index of refraction = 1.42672 Gf8s?l  
Set pupil diameter = 4 'H9=J*9oG  
DONE! _<ut)G^9