[技术]Arizona眼睛模型 [复制链接]

简介 _EOQ*K#=Ct  
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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。 s} ,p>8  
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模型 PKu+$  
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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。 .8CR \-
  
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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. S 1|[}nYP  
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光源 U\y];\~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。 8|?$KLz?F>  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 uA:|#mO  
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视网膜的散射 cI'&gT5  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 %?_pSH}$!  
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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。 29pIO]8;  
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脚本 veAGUE %3  
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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： qp^O\>c  
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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。 "kz``6C  
余下的脚本计算与屈光度有关的所有参数。 Wj/.rG&tE  
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分析 U/m6% )Yx(  
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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。 1-1x,U7w  
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脚本代码 //\ORJ
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. m]+g[L?-  
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Dim entity As T_ENTITY UBrYN'QRNt  
Dim op As T_OPERATION pRD8/7@(B{  
Dim mat As T_MODELMATERIAL Z'>Xn^  
Dim A As Double j\("d4n%C  
Dim pupilDiam As Double  RN'|./N  
Dim eID As Long /fWVgyW>6  
Dim parID As Long nfq  
Dim count As Integer c</d1xT  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /);cl;"  
Dim tlens As Double, nlens As Double B5IS-d  
Dim curv As Double, conic As Double /<9VKMR_k  
Dim ok As Long DT8|2"H  
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Sub Main vX]\Jqy  
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    '用户输入对话框 vAbMU  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 AiykIER/  
        TextBox 220,21,40,21,.TextBox1 'default: 0 G?{BVWtl}  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 gXZ.je)NM  
        OKButton 40,91,90,21 K~5QL/=1  
        CancelButton 190,91,90,21 8=FP92X  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 #{1w#Iz;  
        TextBox 220,49,40,21,.TextBox2 'default: 4 =2BGS\$#  
    End Dialog KcglpKV`  
    Dim dlg As UserDialog Pq>r|/~_  
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    ok = Dialog (dlg) # nwEF QA  
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    If ok=0 Then    'cancel button was pressed }a,j1r_Hl&  
        Print "Execution cancelled." ^<'5 V)  
        End 9; HR  
    End If DF-`nD  
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    'Assign accommodation and pupil diameter & use defaults if field left empty _|bIl%W;\'  
    If dlg.TextBox1 = "" Then "GEJ9_a[  
        A = 0           'Default accommodation M2(+}gv;7p  
    Else 3XYCtp8  
        A = CDbl(dlg.TextBox1) +u#;k!B/>  
    End If ZWQrG'$?o8  
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    If dlg.TextBox2 = "" Then sWP5=t(i+9  
        pupilDiam = 4   'Default pupil diameter n$g g$<  
    Else !5wm9I!5^  
        pupilDiam = CDbl(dlg.TextBox2) K4YpE}]u  
    End If 2--"@@  
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    Print " " %|}obiV)  
    Print "Accommodation = " & A & " Diopters" R"EX$Zj^E  
    Print "Pupil Diameter = " & pupilDiam & " mm" .8S6;xnkC  
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    ' Calculate new parameters with accommodation +VkhM;'"C  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness m{  .'55  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens , \|S BS  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens <UOx>=h  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens BoE;,s>]NW  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens m_\w)  
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    tlens = 3.767 + 0.04*A                  'Lens thickness >!MOgLO3  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 0f}zm8p7.  
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    'Adjust parameters to account for accommodation Fq>=0 )  
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    '************************************************************************* U~n>k<`sr  
    'Aqueous thickness (Position of Lens) ,)e&u1'  
    '************************************************************************* \Z-T)7S  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 19Xc0ez  
    GetCustomElement eID, entity r!N)pt<g  
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    parID = FindFullName( "Geometry.Arizona Eye" ) l2QO\O I9m  
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    ' Delete any shift(s) in z j/`-x  
    count = 0 rVgz+'rFD[  
    While GetOperationCount(eID)>count x%ju(B>  
        GetOperation eID, count, op 4bLk+EY4A  
        If op.Type="ShiftZ" Then ~G|u
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            DeleteOperation eID,count 99w;Q 2k  
            count=count-1 LW<DhMV  
        End If S*-n%D0q5  
        count=count+1 WJbdsPs  
    Wend 64;F g/t  
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    'Set new shift in ]#=43  
    op.Type = "ShiftZ" 1ThONrxu  
    op.val1 = taq gKy@$at&  
    op.parent = parID g^ZsV:D  
    AddOperation eID, op ~WXT0-,  
    Print "Set aqueous humor thickness = " & taq-0.55 6X2>zUHR  
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    '************************************************************************* ?tS=rqc8oW  
    'Radius and conic constant of anterior lens P=PcO>  
    '************************************************************************* y^7;I-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) -6a4H?L  
    GetConic eID, entity, curv, conic 5ws|4V  
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    SetConic eID, entity, 1/Rant, CCant 2<HG=iSf  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant d\Cx(Lb[  
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    '************************************************************************* EV{kd.=f  
    'Radius and conic constant of posterior lens 1cPm $=B  
    '************************************************************************* ;/+VHZP;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) mi9BC9W(  
    GetConic eID, entity, curv, conic 8:^`rw4a0  
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    SetConic eID, entity, 1/Rpost, CCpost "^E/N},%u5  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ?mKj+Bk2  
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    '************************************************************************* E +\?|q !T  
    'Lens thickness (Position of posterior lens surface) k$ k/U  
    '************************************************************************* B;Pws$J  

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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Q-([3%  
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    ' Delete any z-shift(s) jO xH'1I  
    count = 0 YI05?J}  
    While GetOperationCount(eID)>count YT7,=k_  
        GetOperation eID, count, op Sh'>
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        If op.Type="ShiftZ" Then C@+"d3  
            DeleteOperation eID,count lrSdFJ%  
            count=count-1 %gj's-!!  
        End If l%"[857  
        count=count+1 b]S4\BBT  
    Wend FlJ(V  
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    'Set new z-shift w5*?P4P  
    op.Type = "ShiftZ" XQC
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    op.val1 = tlens |Y'xtOMX  
    op.parent = parID ]~S,K}T  
    AddOperation eID, op #N%ATV  
    Print "Set lens thickness = " & tlens ;\(Wz5Ok&J  
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    '************************************************************************* 9_Tk8L#  
    'Lens index of refraction VsS.\1  
    '************************************************************************* bz!9\D|h  
    eID = FindMaterial( "Lens" ) Co6ghH7T  
    GetModelMaterial eID, mat (I3:u-A  
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    mat.Nd = nlens XVXiiQ^  
    SetModelMaterial eID, mat d>"t*>i]>  
    Print "Set lens index of refraction = " & nlens 8joJe>9VJ  
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    '************************************************************************* -$Bom  
    'Pupil diameter AWlR" p2  
    '************************************************************************* w)I!q&`Y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 0{|ib !  
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    'Adjust pupil diameter (trimming volume inner hole) > Q1r^  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ?DP]#9/4  
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    ' Adjust pupil location to just in front of the lens ow:}NI  
    parID = FindFullName( "Geometry.Arizona Eye" ) I"awvUP]a[  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) I#(D.\P  
    count = 0 h
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    While GetOperationCount(eID)>count M$O}roOa  
        GetOperation eID, count, op 0gNwC~IA8  
        If op.Type="ShiftZ" Then vn;_|NeSf  
            DeleteOperation eID,count )W^Wqa8mG|  
            count=count-1 n"B"Aysz  
        End If arf`%9M  
        count=count+1 W-mi1l^H{  
    Wend nA8]/r1k  
    op.Type = "ShiftZ" }>:v  
    op.val1 = taq-0.01 zo66=vE!  
    op.parent = parID +gb2>fei&  
    AddOperation eID, op /|] %0B  
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    Print "Set pupil diameter = " & pupilDiam S!gV\gEbDj  
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    'Update AZ Eye subassembly Description ;c73:'e  
    eID = FindFullName( "Geometry.Arizona Eye" ) K~$o2a e  
    GetEntity eID, entity Zyqh
  
    entity.Description = "Accommodation = " & A & "D" .v[8ie  
    SetEntity eID, entity [sG=(~B
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    Update @ ?y(\>  
    Print "DONE!" 31mY]Jve"  
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End Sub Q7]:vs)%  
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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： +=I_3Wtth  
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Accommodation = 4 Diopters k!E`Xeob  
Pupil Diameter = 4 mm k^I4z^O=-;  
Set aqueous humor thickness = 2.81 xy`aR< L  
Set anterior lens radius = 10.4 and conic constant = -2.375869 (1\!6  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 qA:CV(Z  
Set lens thickness = 3.927 Cec!{]DL&  
Set lens index of refraction = 1.42672 Q%4>okj,  
Set pupil diameter = 4 vW6Pf^yJ  
DONE! ?bbu^;2*f