[技术]Arizona眼睛模型 [复制链接]

简介 viJP
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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。 K)^8 :nt  
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模型 f`iDF+h<6  
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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。 z0%tBgqY(  
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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. ZZ T 9t#~  
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光源 Cu_-QE  
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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。 o$Y#C{
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 R\<d&+q@  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 de;CEm<n  
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视网膜的散射 <AK9HPxP  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 h6}rOchj  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ~,Yd.?.TI  
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脚本 itg"dGDk  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： GB;_!69I  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 g9=_^^Tg  
余下的脚本计算与屈光度有关的所有参数。 ddbQFAQQQ  
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分析 F)Z9Qlo  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Z$B%V t  
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脚本代码 8'NT_NPNb  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 9p1@Lfbj  
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Dim entity As T_ENTITY <_]W1V:0  
Dim op As T_OPERATION ~N7;. 3 7  
Dim mat As T_MODELMATERIAL _^`V0>Mh:  
Dim A As Double zbGZ\pz  
Dim pupilDiam As Double owI:Qs_/4  
Dim eID As Long V-E 77u6{0  
Dim parID As Long >;R7r|^k  
Dim count As Integer ((<\VQ,>(  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Rf2mBjJ(z  
Dim tlens As Double, nlens As Double b|;h$
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Dim curv As Double, conic As Double mIPDF1=)  
Dim ok As Long Mz86bb^J  
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Sub Main  Mz+vT0  
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    '用户输入对话框 >YsM'.EFD  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Pc7p2  
        TextBox 220,21,40,21,.TextBox1 'default: 0 cYXL3)p*Q  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 I?Z"
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        OKButton 40,91,90,21 TP~1-(M)}  
        CancelButton 190,91,90,21 IGi9YpI&K  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "@|rU4Y  
        TextBox 220,49,40,21,.TextBox2 'default: 4 tOxH9  
    End Dialog *B84Y.df  
    Dim dlg As UserDialog d @ l  
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    ok = Dialog (dlg) #{^qBP
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    If ok=0 Then    'cancel button was pressed M{jq6c  
        Print "Execution cancelled." \=`jo$S  
        End ,oPxt  
    End If pf+VYZ#)  
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    'Assign accommodation and pupil diameter & use defaults if field left empty bI_MF/r''  
    If dlg.TextBox1 = "" Then ]0[ot$Da6  
        A = 0           'Default accommodation g!o2vTt5  
    Else euW   
        A = CDbl(dlg.TextBox1) ^HtB!Xc  
    End If `e?~c'a@  
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    If dlg.TextBox2 = "" Then Qw }1mRv  
        pupilDiam = 4   'Default pupil diameter y$_]}<b  
    Else g}uSIv^  
        pupilDiam = CDbl(dlg.TextBox2) LR\8M(rtvH  
    End If 5tzO=gO[  
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    Print " " 8OO[Le]1  
    Print "Accommodation = " & A & " Diopters" fO .=i1 E}  
    Print "Pupil Diameter = " & pupilDiam & " mm" m6]6!_  
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    ' Calculate new parameters with accommodation 7s!rer>  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ' I!/I  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 412E7   
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens zMBGpqdP  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;sqxFF@  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens bR~5 :A^  
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    tlens = 3.767 + 0.04*A                  'Lens thickness q">}3`
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction yF%e)6  
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    'Adjust parameters to account for accommodation }UQ,B  
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    '************************************************************************* 0vBQzM Q  
    'Aqueous thickness (Position of Lens) pG"hZB3)  
    '************************************************************************* ;ceg:-Zqo  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) t)g%9 k^  
    GetCustomElement eID, entity T!HAE#xC  
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    parID = FindFullName( "Geometry.Arizona Eye" ) C>mFyl
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    ' Delete any shift(s) in z RrYNtc  
    count = 0 s0/m qZ]s  
    While GetOperationCount(eID)>count jp@X,HES  
        GetOperation eID, count, op csxn"Dz\  
        If op.Type="ShiftZ" Then ,dw\y/d
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            DeleteOperation eID,count Q~k|lTf  
            count=count-1 ^tWSu?9  
        End If W1t_P&i  
        count=count+1 m}zXy\  
    Wend qt/6o|V  
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    'Set new shift in *yo'Nqu  
    op.Type = "ShiftZ" a|#pl!  
    op.val1 = taq P4c3kO0  
    op.parent = parID #o9CC)q5G  
    AddOperation eID, op :(tK
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    Print "Set aqueous humor thickness = " & taq-0.55 OYn5k6  
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    '************************************************************************* l @@pXg3  
    'Radius and conic constant of anterior lens F MYcZ+4  
    '************************************************************************* @PhAg  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6Yt3Oq<U  
    GetConic eID, entity, curv, conic :,j^ei  
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    SetConic eID, entity, 1/Rant, CCant @\xEK5SG  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8x7TK2r  
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    '************************************************************************* :,
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    'Radius and conic constant of posterior lens .h4
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    '************************************************************************* E?|NYu#I6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) b&1hj[`)  
    GetConic eID, entity, curv, conic u|u)8;'9(  
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    SetConic eID, entity, 1/Rpost, CCpost H1KXAy`&  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Gv }  
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    '************************************************************************* O&~ @ior  
    'Lens thickness (Position of posterior lens surface) 7Q~W}`Qv'  
    '************************************************************************* hb/Z{T'  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) |E||e10wR  
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    ' Delete any z-shift(s) >c
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    count = 0 b].U/=Hs  
    While GetOperationCount(eID)>count [eTEK W]  
        GetOperation eID, count, op 7M5HvG#w%  
        If op.Type="ShiftZ" Then p} 
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            DeleteOperation eID,count US-f<Wq  
            count=count-1 
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        End If *`/4KMrq  
        count=count+1 -ik((qx_  
    Wend D(dV{^} 9  
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    'Set new z-shift [
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    op.Type = "ShiftZ" BC1smSlJ  
    op.val1 = tlens lU&2K$`  
    op.parent = parID +
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    AddOperation eID, op ~HT:BO$  
    Print "Set lens thickness = " & tlens n-qle5sj  
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    '************************************************************************* US9@/V*2  
    'Lens index of refraction R3)ccom  
    '************************************************************************* v~._]f$:  
    eID = FindMaterial( "Lens" ) aYHs35  
    GetModelMaterial eID, mat ^"vmIC.h  
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    mat.Nd = nlens VAyAXN~  
    SetModelMaterial eID, mat j>v8i bS(  
    Print "Set lens index of refraction = " & nlens .N\t3\9}  
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    '************************************************************************* mYXL  
    'Pupil diameter qvhG^b0h  
    '*************************************************************************  z{V#_(  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) YWV)C?5x&  
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    'Adjust pupil diameter (trimming volume inner hole) fmUrwI1 %  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 9Q\B1Q  
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    ' Adjust pupil location to just in front of the lens \X]I: 0^j  
    parID = FindFullName( "Geometry.Arizona Eye" ) Pmr'W\aIR  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) q1r-xsjV=  
    count = 0 F%%mcmHD#  
    While GetOperationCount(eID)>count ,5 
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        GetOperation eID, count, op ('d,Sh  
        If op.Type="ShiftZ" Then ,MHF  
            DeleteOperation eID,count /!/Pk'p=/  
            count=count-1 B/hQvA;(  
        End If gssEdJ  
        count=count+1 ;9J6)zg !n  
    Wend G-]_ d  
    op.Type = "ShiftZ" b0se-#+  
    op.val1 = taq-0.01 G[OJ<px  
    op.parent = parID Eb29tq  
    AddOperation eID, op 9~K+
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    Print "Set pupil diameter = " & pupilDiam
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    'Update AZ Eye subassembly Description ']OT7)_
 
    eID = FindFullName( "Geometry.Arizona Eye" ) :inVwc  
    GetEntity eID, entity j[t2Bp  
    entity.Description = "Accommodation = " & A & "D" hW;n^\lF#e  
    SetEntity eID, entity EgzdRB\Cf  
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    Update ;LKYA?=/V  
    Print "DONE!" F^}d>2W(  
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End Sub ,&Zk63V  
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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： 2:yXeSeA  
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Accommodation = 4 Diopters O\%0D.HEz  
Pupil Diameter = 4 mm v`6vc)>8  
Set aqueous humor thickness = 2.81 OsYZa`$,  
Set anterior lens radius = 10.4 and conic constant = -2.375869 @x*,fk  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &{q'$oF  
Set lens thickness = 3.927 yaHkWkl =  
Set lens index of refraction = 1.42672 '?X?'_3  
Set pupil diameter = 4 C}9|e?R[Rz  
DONE! \3F)M`g