[技术]Arizona眼睛模型 [复制链接]

简介 GoSdo  
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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。 C6` Tck!  
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模型 \k 9EimT}  
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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。 ?2q4dx0  
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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. kD*r@s]=  
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光源 M1HGXdN*B  
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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。 VPi*9(LS  
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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。 u,~/oTgO  
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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。 vCX
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视网膜的散射 Ci9]#)"c  
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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。 &*j# [6  
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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。 c9O0YQ3&8  
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脚本 Eg+z(m$M  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： NTV@
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 M$Or|HT
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余下的脚本计算与屈光度有关的所有参数。 tRYi q  
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分析 b wqd`C  
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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。 (|dN6M-.K  
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脚本代码 |2!cPf^8  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7N8a48$8  
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Dim entity As T_ENTITY 2)T.Ci cx  
Dim op As T_OPERATION fI }v}L^  
Dim mat As T_MODELMATERIAL v=J[p;H^H  
Dim A As Double ov|/=bzro  
Dim pupilDiam As Double o2_mcJ  
Dim eID As Long e)#f`wM  
Dim parID As Long oGKk2oP  
Dim count As Integer 9B
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double chszP{-@X  
Dim tlens As Double, nlens As Double mw flx8  
Dim curv As Double, conic As Double dkAY%ztwo  
Dim ok As Long cr>"LAi  
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Sub Main u&Cu"-%=M  
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    '用户输入对话框 :\69N/uw`  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 4h$W4NJK  
        TextBox 220,21,40,21,.TextBox1 'default: 0 wq>0W4(  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 `3'4_@7s9  
        OKButton 40,91,90,21
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        CancelButton 190,91,90,21 Np2.X+  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |.{[%OJP  
        TextBox 220,49,40,21,.TextBox2 'default: 4 uoMDf{d  
    End Dialog '[`pU>9  
    Dim dlg As UserDialog !~QmY,R  
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    ok = Dialog (dlg)
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    If ok=0 Then    'cancel button was pressed SwdUElEp  
        Print "Execution cancelled." &k@r23V7r  
        End m$H(l4wB>  
    End If o 4cqLMu  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 'Ej&zh  
    If dlg.TextBox1 = "" Then >*e,+ok  
        A = 0           'Default accommodation f{ER]U  
    Else .?LP$O=  
        A = CDbl(dlg.TextBox1) hM~zO1XW  
    End If `>N_A!pr`  
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    If dlg.TextBox2 = "" Then @DniYt/  
        pupilDiam = 4   'Default pupil diameter U`)o$4Bq  
    Else 1%k$9[!l%  
        pupilDiam = CDbl(dlg.TextBox2) MtXTh*4  
    End If ,Vr'F  
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    Print " " HN~  
    Print "Accommodation = " & A & " Diopters" (@ixV$Y  
    Print "Pupil Diameter = " & pupilDiam & " mm" G;yh$n<"  
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    ' Calculate new parameters with accommodation Jwe9L^gL  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness +lED6]+%  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?nV& :~eY  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens pipqXe  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 9vw0box  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Hribk[99  
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    tlens = 3.767 + 0.04*A                  'Lens thickness cUK
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction W=ar&O~}n  
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    'Adjust parameters to account for accommodation 1@ .Eh8y  
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    '************************************************************************* J)"g`)\2+  
    'Aqueous thickness (Position of Lens) 0MX``/Z72  
    '************************************************************************* jw$[b=sa  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) %\QK/`krp  
    GetCustomElement eID, entity TF-k|##G  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 3lT>C'qq  
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    ' Delete any shift(s) in z t%Hy#z1W_  
    count = 0 oRQJ YH  
    While GetOperationCount(eID)>count gy6Pf4Yo  
        GetOperation eID, count, op GMJ</xG
  
        If op.Type="ShiftZ" Then 7-`iI(N<  
            DeleteOperation eID,count <{kr5<  
            count=count-1 0VBbSn}Z<  
        End If yx&'W_Q@  
        count=count+1 P8=!/L2?  
    Wend |A%Jx__  
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    'Set new shift in YMfjTt@Q  
    op.Type = "ShiftZ" mOE%:xq9-  
    op.val1 = taq _pe_w{V-b6  
    op.parent = parID xIb^x=|h  
    AddOperation eID, op TX7]$Wj  
    Print "Set aqueous humor thickness = " & taq-0.55 VdetY\  
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    '************************************************************************* %YbcI|i]<0  
    'Radius and conic constant of anterior lens LH]<+Zren  
    '************************************************************************* WZ]f \S  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) B`i5lD  
    GetConic eID, entity, curv, conic csNB \  
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    SetConic eID, entity, 1/Rant, CCant AHl1{* [  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant }Rx`
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    '************************************************************************* /Xo8 kC  
    'Radius and conic constant of posterior lens M9scZuj  
    '************************************************************************* Od5I:p]N  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 0}d^UGD  
    GetConic eID, entity, curv, conic TqN4OkCm/  
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    SetConic eID, entity, 1/Rpost, CCpost 2qkZ B0[  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost @ky<5r*JU(  
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    '************************************************************************* !.}ZlA  
    'Lens thickness (Position of posterior lens surface) |NoTwK  
    '************************************************************************* l6O8:XI  

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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) do>,ELS+m  
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    ' Delete any z-shift(s) F:B8J4/  
    count = 0 4UV<Q*B\F  
    While GetOperationCount(eID)>count -IF3'VG  
        GetOperation eID, count, op s%c
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        If op.Type="ShiftZ" Then Sh+$w=vC  
            DeleteOperation eID,count isiehKkD
 
            count=count-1 O<EFm}Ae  
        End If \)'o{l&  
        count=count+1 (Sd8S`xO  
    Wend |>U:Pb(  
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    'Set new z-shift CW)JS3}W"  
    op.Type = "ShiftZ" o<Z  
    op.val1 = tlens bxrT[]  
    op.parent = parID 9KgGK cy%  
    AddOperation eID, op *~>}*  
    Print "Set lens thickness = " & tlens vz1yH%~E  
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    '************************************************************************* ~aZy52H_#.  
    'Lens index of refraction >ukn
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    '************************************************************************* :psP|7%|  
    eID = FindMaterial( "Lens" ) i3[%]_eP.  
    GetModelMaterial eID, mat D{)K00mm  
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    mat.Nd = nlens a6<UMJ  
    SetModelMaterial eID, mat fC7rs5  
    Print "Set lens index of refraction = " & nlens K\3N_ztu  
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    '************************************************************************* *\!>22*  
    'Pupil diameter `EJ.L6j$'  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) EpsjaOmAF  
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    'Adjust pupil diameter (trimming volume inner hole) A$=h'!$  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" HkL`- c0  

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    ' Adjust pupil location to just in front of the lens c`E0sgp  
    parID = FindFullName( "Geometry.Arizona Eye" ) |@*3 nb8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) i] I{7k  
    count = 0 gL(_!mcwu  
    While GetOperationCount(eID)>count :H(wW   
        GetOperation eID, count, op Z&![W@m@0N  
        If op.Type="ShiftZ" Then =lOdg3#\a  
            DeleteOperation eID,count d"0=.sA  
            count=count-1 )kpNg:2p  
        End If uK;&
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        count=count+1 6a!b20IZh  
    Wend pg9feIW1  
    op.Type = "ShiftZ" =73aME}  
    op.val1 = taq-0.01 WM8])}<L  
    op.parent = parID ][TA7pDPV  
    AddOperation eID, op h7a/]~  
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    Print "Set pupil diameter = " & pupilDiam 6F8TiR&  
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    'Update AZ Eye subassembly Description a9N$I@bi]  
    eID = FindFullName( "Geometry.Arizona Eye" ) ~LF1$Cai  
    GetEntity eID, entity qvC2BQ  
    entity.Description = "Accommodation = " & A & "D" ?[!_f$50]P  
    SetEntity eID, entity =_=0l+\}  
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    Update 3'zL,WW  
    Print "DONE!" @=NTr  
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End Sub ym;I(TC+  
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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： j^)=<+Q;=  
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Accommodation = 4 Diopters yW]>v>l:Eg  
Pupil Diameter = 4 mm 8O| w(z  
Set aqueous humor thickness = 2.81 dthtWnB@  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ecMpU8}rR  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 E|"QYsi.Ck  
Set lens thickness = 3.927 -_^#7]  
Set lens index of refraction = 1.42672 %{B4M#~  
Set pupil diameter = 4 ZYLPk<<  
DONE! |<2<`3