[技术]Arizona眼睛模型 [复制链接]

简介 9qG6Pb  
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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。 e**qF=HCw  
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模型 &KRX[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。 65Yv4pNL  
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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. SI-Ops~e  
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光源 j eP  
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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。 v^ VitLC  
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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。 7%eK37@u  
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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。 ,1o FPa{?  
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视网膜的散射 8c^TT&  
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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。 + @s"zp;F  
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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。 _^%,x  
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脚本 lp%pbx43s  
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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： ^yN&ZI3P&  
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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。 Q:d]imw!O  
余下的脚本计算与屈光度有关的所有参数。 Od,qbU4O  
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分析 57  
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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。 _TQj
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脚本代码 Ig0VW)@  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6) [H?Q  
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Dim entity As T_ENTITY y(yHt=r  
Dim op As T_OPERATION v\%HPMlh  
Dim mat As T_MODELMATERIAL [MM~H0=s  
Dim A As Double 1JG'%8}#8  
Dim pupilDiam As Double x@;m8z0  
Dim eID As Long 4*cEag   
Dim parID As Long =|y9UlsD  
Dim count As Integer =ncVnW{  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double tpQ(g%  
Dim tlens As Double, nlens As Double r1{@Ucw2  
Dim curv As Double, conic As Double 0)e\`
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Dim ok As Long Zaf:fsj>  
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Sub Main hT&Y#fh  
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    '用户输入对话框 9ZsVy
 
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,K"U>&  
        TextBox 220,21,40,21,.TextBox1 'default: 0 W/bQd)Jvk  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 :zke %Yx  
        OKButton 40,91,90,21 4-y:/8  
        CancelButton 190,91,90,21 aa/(N7  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 A>
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        TextBox 220,49,40,21,.TextBox2 'default: 4 k:#!zK}  
    End Dialog 6@F9G4<Z  
    Dim dlg As UserDialog ;)z:fToh  
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    ok = Dialog (dlg) `w7v*h|P  
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    If ok=0 Then    'cancel button was pressed $$;M^WV^?.  
        Print "Execution cancelled." =M[bnq*\  
        End .K2qXw"S#  
    End If 1POmP&fI(  
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    'Assign accommodation and pupil diameter & use defaults if field left empty &P}_bx  
    If dlg.TextBox1 = "" Then BWv^zi  
        A = 0           'Default accommodation x$.^"l-vX  
    Else :B5Fdp3  
        A = CDbl(dlg.TextBox1) U175{N%3  
    End If ;yLu R  
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    If dlg.TextBox2 = "" Then
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        pupilDiam = 4   'Default pupil diameter Y^;ovH~ ve  
    Else N06OvU2>xU  
        pupilDiam = CDbl(dlg.TextBox2) S.94edQ  
    End If .*?wF  
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    Print " " t?-n*9,#S  
    Print "Accommodation = " & A & " Diopters" Ml{Z  
    Print "Pupil Diameter = " & pupilDiam & " mm" aFb==73aLw  
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    ' Calculate new parameters with accommodation {JO  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness #@9/g  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens wc NOLUl  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~hnQUS`A  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens k"T}2 7  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 0KcyLAJ  
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    tlens = 3.767 + 0.04*A                  'Lens thickness V6&!9b  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction RXpw!  
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    'Adjust parameters to account for accommodation UXc-k  
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    '************************************************************************* dGYn4i2k?  
    'Aqueous thickness (Position of Lens) 1R{!]uh  
    '************************************************************************* z0p*Z&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) /ivJsPH  
    GetCustomElement eID, entity 0neoE E  
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    parID = FindFullName( "Geometry.Arizona Eye" ) j9x<Y]  
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    ' Delete any shift(s) in z <CYd+! (  
    count = 0 L%*!`T
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    While GetOperationCount(eID)>count 
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        GetOperation eID, count, op Sz)' ogl  
        If op.Type="ShiftZ" Then SO|NaqWa  
            DeleteOperation eID,count fNli  
            count=count-1 +qtJaYf/0  
        End If zUkgG61  
        count=count+1 ^pAAzr"h
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    Wend nX6u(U  
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    'Set new shift in d6?j`~[7#-  
    op.Type = "ShiftZ" 8rnwXPBN  
    op.val1 = taq Fh?gNSWq6  
    op.parent = parID $Uq|w[LA  
    AddOperation eID, op (Ft+uuG  
    Print "Set aqueous humor thickness = " & taq-0.55 1b`1{%  
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    '************************************************************************* ~rE|%o  
    'Radius and conic constant of anterior lens }l(&}#dY  
    '************************************************************************* M)J5;^["  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) DbBcQ%  
    GetConic eID, entity, curv, conic 'NXN& {  
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    SetConic eID, entity, 1/Rant, CCant nMq,F#`3N  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant EA@.,7F  
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    '************************************************************************* GfxZ'VIn  
    'Radius and conic constant of posterior lens 9|^2",V  
    '************************************************************************* ~WeM TXF>y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Z, zWuE3  
    GetConic eID, entity, curv, conic :[p}  
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    SetConic eID, entity, 1/Rpost, CCpost qTRsZz@  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost !_]Y~[  
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    '************************************************************************* :;RMo2Tl  
    'Lens thickness (Position of posterior lens surface) @
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    '************************************************************************* ?hZAxR\  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Avge eJi  
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    ' Delete any z-shift(s) BA@lk+aW  
    count = 0 .wEd"A&j  
    While GetOperationCount(eID)>count uanhr)Ys  
        GetOperation eID, count, op (+w*[qHe  
        If op.Type="ShiftZ" Then & TCkpS  
            DeleteOperation eID,count 1jmjg~W  
            count=count-1 =J
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        End If afCW(zHp  
        count=count+1 Q
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    Wend \0^Kram>
 
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    'Set new z-shift NJ%P/\ C  
    op.Type = "ShiftZ" _>o:R$ %}  
    op.val1 = tlens f$o_e90mu  
    op.parent = parID 3<e=g)F  
    AddOperation eID, op iOf<$f  
    Print "Set lens thickness = " & tlens pE3?"YO  
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    '************************************************************************* ~T"Rw2vb  
    'Lens index of refraction WqR&&gz  
    '************************************************************************* ,5P0S0*{  
    eID = FindMaterial( "Lens" ) s-NX 
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    GetModelMaterial eID, mat M:=J^0  
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    mat.Nd = nlens 9sM!`Lz{  
    SetModelMaterial eID, mat +X\FBvP&  
    Print "Set lens index of refraction = " & nlens N_LM/of|D  
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    '************************************************************************* {Ea b j  
    'Pupil diameter Q8$}@iA[  
    '************************************************************************* Ky`qskvu  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;_XFo&@  
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    'Adjust pupil diameter (trimming volume inner hole) (Nq=H)cm8  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" HRpte=`q  
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    ' Adjust pupil location to just in front of the lens 8%:Iv(UMk  
    parID = FindFullName( "Geometry.Arizona Eye" ) [XN={  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 1wii8B6  
    count = 0 9v#CE!  
    While GetOperationCount(eID)>count Mg+2. 8%  
        GetOperation eID, count, op YByLoM*  
        If op.Type="ShiftZ" Then .w:DFk^E]b  
            DeleteOperation eID,count 6u?>M9  
            count=count-1 ),_@WW;k  
        End If y1z4ik)Sd@  
        count=count+1 {aZ0;  
    Wend xKbXt;l2  
    op.Type = "ShiftZ" v<k?Vu  
    op.val1 = taq-0.01 T%+#xl  
    op.parent = parID t <~h'U  
    AddOperation eID, op -$\y_?}  
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    Print "Set pupil diameter = " & pupilDiam REQ\>UO_  
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    'Update AZ Eye subassembly Description L]7=?vN=8  
    eID = FindFullName( "Geometry.Arizona Eye" ) $Ph|e)p  
    GetEntity eID, entity ]IaMp78
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    entity.Description = "Accommodation = " & A & "D" K&u_R  
    SetEntity eID, entity $+Z[K.2J  
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    Update b\f O8{k  
    Print "DONE!" gE-tjoJ  
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End Sub 4>YR{  
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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： "> ypIR<  
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Accommodation = 4 Diopters %64)(z  
Pupil Diameter = 4 mm TT%M'5&  
Set aqueous humor thickness = 2.81 oE@a'*.\  
Set anterior lens radius = 10.4 and conic constant = -2.375869 @ 6\I~s(  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 D'>_I.  
Set lens thickness = 3.927 x%=si[P  
Set lens index of refraction = 1.42672 m<G,[Yc  
Set pupil diameter = 4 #&+{mCjs  
DONE! P.se'z)E