[技术]Arizona眼睛模型 [复制链接]

简介 1<$z-y'  
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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。 u3])_oj=  
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模型 (^9dp[2  
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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。 D!5{CQl  
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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. L1u(\zw  
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光源 o~tL;(sz  
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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。 #-9@*FFL,  
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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。 CaqqH`/E4  
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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。 LR Dj!{k{  
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视网膜的散射 cd:VFjT  
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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。 }Sv\$h  
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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。 E)]RQ~jY?  
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脚本 m 7/b.B}  
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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： J*m~fZ^  
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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。 dO|n[/qL0  
余下的脚本计算与屈光度有关的所有参数。 W}rLHAaDh  
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分析 /`VrV{\/!  
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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。 H-5h-p k  
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脚本代码 h7cE"m  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. @D7/u88|  
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Dim entity As T_ENTITY -PLh|  
Dim op As T_OPERATION j5V{,lf  
Dim mat As T_MODELMATERIAL 1y7FvD~v  
Dim A As Double TDZ p1zpXb  
Dim pupilDiam As Double {RHa1wc  
Dim eID As Long 
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Dim parID As Long :BpXi|n;  
Dim count As Integer 3"p'WZ>  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double (Qj;B)
 
Dim tlens As Double, nlens As Double *rv7#!].  
Dim curv As Double, conic As Double !X ={a{<,T  
Dim ok As Long !G~`5?CvE  
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Sub Main L#Rj~&U  
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    '用户输入对话框 xa$4P [  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 S- JD}+9  
        TextBox 220,21,40,21,.TextBox1 'default: 0 W~d^ *LZt  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Tjj-8cg  
        OKButton 40,91,90,21 zp:EssO=Q  
        CancelButton 190,91,90,21 $3yn-'o'A  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 (%SKTM  
        TextBox 220,49,40,21,.TextBox2 'default: 4 X^7n/|%*.  
    End Dialog :[!b";pR  
    Dim dlg As UserDialog ` 3h,Cy^  
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    ok = Dialog (dlg) ,^@z;xF  
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    If ok=0 Then    'cancel button was pressed m)e~HP7M  
        Print "Execution cancelled." uQO\vRh0  
        End CC|=$(PgT  
    End If Ob@HzXH  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ~w"e 2a  
    If dlg.TextBox1 = "" Then wrAcVR  
        A = 0           'Default accommodation RKD$'UWX  
    Else e1Bqd+  
        A = CDbl(dlg.TextBox1) JGQ)/(  
    End If %z"n}|%!  
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    If dlg.TextBox2 = "" Then \vF*n Z5/  
        pupilDiam = 4   'Default pupil diameter ~%QI#s?|  
    Else !;M5.Y1j&"  
        pupilDiam = CDbl(dlg.TextBox2) Eu`K2_
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    End If O[15xH,  
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    Print " " H/$oGhvl  
    Print "Accommodation = " & A & " Diopters" I;+>@Cn(g<  
    Print "Pupil Diameter = " & pupilDiam & " mm" |DLmMsS4  
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    ' Calculate new parameters with accommodation tLzKM+Ct#  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Dn@Sjsj>  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens npMPjknl  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens F~wqt7*  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens }T&~DVM  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 2!?=I'uMA  
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    tlens = 3.767 + 0.04*A                  'Lens thickness _ pO1XM  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction A?"/ >LM  
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    'Adjust parameters to account for accommodation g<^-[w4/  
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    '************************************************************************* T0"q,lrdxV  
    'Aqueous thickness (Position of Lens) gp NAM"  
    '************************************************************************* ]. 0;;v6)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :ioD*k  
    GetCustomElement eID, entity O:jaA3  
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    parID = FindFullName( "Geometry.Arizona Eye" ) d/lV+yZ  
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    ' Delete any shift(s) in z S3gd'Bahq  
    count = 0 PE<(eIr  
    While GetOperationCount(eID)>count `c?8i  
        GetOperation eID, count, op X1o=rT  
        If op.Type="ShiftZ" Then =O>E>Q  
            DeleteOperation eID,count Ti$_V_  
            count=count-1 nTCwLnX(O  
        End If kerBy
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        count=count+1 f[-$##S.~  
    Wend Ue(\-b\)  
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    'Set new shift in :I8HRkp  
    op.Type = "ShiftZ" c|Fu6LF a  
    op.val1 = taq M`H@ % M  
    op.parent = parID K(rWM>Jv  
    AddOperation eID, op |nmt /[  
    Print "Set aqueous humor thickness = " & taq-0.55 $fG~;`T  
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    '************************************************************************* tf6 Zz[  
    'Radius and conic constant of anterior lens g[(Eh?]Sc  
    '************************************************************************* A$-\Er+f  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) s^HI%mdf  
    GetConic eID, entity, curv, conic qqSFy>`P  
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    SetConic eID, entity, 1/Rant, CCant j> dL:V&`  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant t>h:s3c  
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    '************************************************************************* w]O,xO  
    'Radius and conic constant of posterior lens R})b%y`]  
    '************************************************************************* i=jYl  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) G#j~8`3X  
    GetConic eID, entity, curv, conic fT.MglJcb  
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    SetConic eID, entity, 1/Rpost, CCpost a([8r- zP  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Zu|qN*N4  
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    '************************************************************************* |jb,sd[=S  
    'Lens thickness (Position of posterior lens surface) q,>4#J[2;s  
    '************************************************************************* 8dwKJ3*.  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) h6Cqc}P  
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    ' Delete any z-shift(s) F~?|d0  
    count = 0 6mV^akapv  
    While GetOperationCount(eID)>count id[caP=`  
        GetOperation eID, count, op zoZ10?ojC  
        If op.Type="ShiftZ" Then ei(S&u<  
            DeleteOperation eID,count lPw`KW  
            count=count-1 
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        End If ^u> fW["[  
        count=count+1 2b&Fu\2Dmv  
    Wend ;),vUu,k  
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    'Set new z-shift vr }-u  
    op.Type = "ShiftZ" 1u~a*lO}  
    op.val1 = tlens 8~AL+*hn  
    op.parent = parID v(p<88.!m  
    AddOperation eID, op QypUBf  
    Print "Set lens thickness = " & tlens 2yV^'o)  
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    '************************************************************************* wY3|5kbDj  
    'Lens index of refraction yiMqe^zy  
    '************************************************************************* Hz j%G>  
    eID = FindMaterial( "Lens" ) 395`Wkv  
    GetModelMaterial eID, mat w%-S5#  
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    mat.Nd = nlens \|
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    SetModelMaterial eID, mat L| ;WE=  
    Print "Set lens index of refraction = " & nlens N1hj[G[H"  
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    '************************************************************************* +*wr=9>  
    'Pupil diameter Ho1V)T
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    '************************************************************************* kAq#cLprG  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) -PTfsQk  
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    'Adjust pupil diameter (trimming volume inner hole) %e(DPX  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" O]KQ]zN  
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    ' Adjust pupil location to just in front of the lens 1p8hn!V  
    parID = FindFullName( "Geometry.Arizona Eye" ) d6)+d9?<  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) t\-|J SZ  
    count = 0 sfk;c#K  
    While GetOperationCount(eID)>count 9-!GYa'Z  
        GetOperation eID, count, op bu{dT8g'U  
        If op.Type="ShiftZ" Then 1Cw HGO  
            DeleteOperation eID,count "[0.a\ d<  
            count=count-1 gv1y%(`|n(  
        End If KbMan~Pb6  
        count=count+1 Cv[1HO<  
    Wend A=wG};%_  
    op.Type = "ShiftZ" g}pD%  
    op.val1 = taq-0.01 AWi+xo|  
    op.parent = parID + ]iK^y-.r  
    AddOperation eID, op *,28@_EwY  
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    Print "Set pupil diameter = " & pupilDiam &Bqu2^^  
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    'Update AZ Eye subassembly Description J?Oeuk~[D  
    eID = FindFullName( "Geometry.Arizona Eye" ) z0Z1J8Qq6.  
    GetEntity eID, entity FH%M5RD  
    entity.Description = "Accommodation = " & A & "D" -b|"%e<'  
    SetEntity eID, entity qfjUJ/  
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    Update w~yC^`  
    Print "DONE!" '4CD }  
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End Sub k8r1)B4ab  
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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： mF4y0r0  
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Accommodation = 4 Diopters h/6^>setz  
Pupil Diameter = 4 mm #qW#>0U  
Set aqueous humor thickness = 2.81 |a%Wd  
Set anterior lens radius = 10.4 and conic constant = -2.375869 F x^X(!)~]  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 3O;"{E= <  
Set lens thickness = 3.927 '.C#"nY>1  
Set lens index of refraction = 1.42672 RhC|x,E  
Set pupil diameter = 4 | AiMx2  
DONE! 3W{!\