[技术]Arizona眼睛模型 [复制链接]

简介 W&A22jO.1  
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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。 w3:Y]F.ot  
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模型 smoz5
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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。 </5uB' B ^  
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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.
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光源 V&-pgxf;  
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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。 j,K]TJ  
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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。 lM3UjR|@  
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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。 ]E .+)>  
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视网膜的散射 ArDkJ`DE  
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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。 N?eWf +C  
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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。
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脚本 8_US.52V  
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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： 8 ;y N  
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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。 Sc_#BD.  
余下的脚本计算与屈光度有关的所有参数。 <t>"b|fW  
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分析 jc)[5i0  
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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。 \R#]}g0!  
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脚本代码 *~~ >?  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. JE9SPFQx9M  
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Dim entity As T_ENTITY >0z(+}]3z  
Dim op As T_OPERATION RoCX*3d  
Dim mat As T_MODELMATERIAL A0Pg|M  
Dim A As Double r9G}[#DO  
Dim pupilDiam As Double [LDsn]{  
Dim eID As Long &,/_"N"?D  
Dim parID As Long ~UA:_7#\M  
Dim count As Integer 8R<2I1xn2  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 't'~p#$,F  
Dim tlens As Double, nlens As Double {XAm3's  
Dim curv As Double, conic As Double FGY4u4y  
Dim ok As Long kXK D>."E*  
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Sub Main 5]D"y Ay81  
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    '用户输入对话框 ?.Z4GWyXa
 
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 N=R|s$,Oy9  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ,$BbJQ5  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 n\Y{?x  
        OKButton 40,91,90,21 ;LSdY}*%0  
        CancelButton 190,91,90,21 L6S!?t.{Yv  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 V`Ve__5;  
        TextBox 220,49,40,21,.TextBox2 'default: 4 F)rU*i7  
    End Dialog R3=PV{`M  
    Dim dlg As UserDialog y^pzqv  
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    ok = Dialog (dlg) M_asf7|
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    If ok=0 Then    'cancel button was pressed :=9?XzCC  
        Print "Execution cancelled." !;EG<ji,gj  
        End >Wvb!8N  
    End If }Jfi"L  
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    'Assign accommodation and pupil diameter & use defaults if field left empty >~C*m `#  
    If dlg.TextBox1 = "" Then $}k
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        A = 0           'Default accommodation >HMuh)  
    Else *Xm$w  
        A = CDbl(dlg.TextBox1) !##OQ  
    End If ^W}(]jL  
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    If dlg.TextBox2 = "" Then o ;nw
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        pupilDiam = 4   'Default pupil diameter ON"F h'?  
    Else 6%'bo`S#  
        pupilDiam = CDbl(dlg.TextBox2) <*I%U]  
    End If 6XU1w  
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    Print " " \Nd8,hE  
    Print "Accommodation = " & A & " Diopters" `x%( n@g  
    Print "Pupil Diameter = " & pupilDiam & " mm" s az<NT  
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    ' Calculate new parameters with accommodation ?&v+-4%4PI  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness o\ss  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens (vL-Z[M!  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens wCT. (d_  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens X'BFR]cm  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens doeYc  
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    tlens = 3.767 + 0.04*A                  'Lens thickness YXeL7W  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 9UF
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    'Adjust parameters to account for accommodation >;|~ z\8  
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    '************************************************************************* ZY NHVR  
    'Aqueous thickness (Position of Lens) !cblmF;0  
    '************************************************************************* |"7F`M96I  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) rK^Sn7U  
    GetCustomElement eID, entity zB,Vi-)vH  
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    parID = FindFullName( "Geometry.Arizona Eye" ) T&@xgj|!)  
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    ' Delete any shift(s) in z =}SH*xi6  
    count = 0 /da5"  
    While GetOperationCount(eID)>count <K6:"  
        GetOperation eID, count, op {[Bo"a>%  
        If op.Type="ShiftZ" Then }r%
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            DeleteOperation eID,count A}./ ;[  
            count=count-1 AHa%?wb  
        End If 7t8[M(  
        count=count+1 3}U {~l!K  
    Wend >b6!*Lrhs  
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    'Set new shift in TgFj-"L\  
    op.Type = "ShiftZ" +@n8DM{b  
    op.val1 = taq x d9+P  
    op.parent = parID oRJ!J-Z]  
    AddOperation eID, op UJhmhI  
    Print "Set aqueous humor thickness = " & taq-0.55 OC(S"&D  
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    '************************************************************************* fMGL1VN  
    'Radius and conic constant of anterior lens
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    '************************************************************************* xbZx&`(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) M|HW$8V3_2  
    GetConic eID, entity, curv, conic &Nzq/~uqP  
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    SetConic eID, entity, 1/Rant, CCant `,-w+3?Al  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant xK7xAO  
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    '************************************************************************* ;F)j,Ywi)H  
    'Radius and conic constant of posterior lens UG@9X/l}  
    '************************************************************************* }8joltf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 8XS_I{}?  
    GetConic eID, entity, curv, conic CxvL!ew  
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    SetConic eID, entity, 1/Rpost, CCpost {>x6SVF  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost FabDK :  
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    '************************************************************************* 9FGe(t<  
    'Lens thickness (Position of posterior lens surface) 1=*QMEv1G  
    '************************************************************************* q?&Ap*  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) $oPx2sb  
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    ' Delete any z-shift(s) .dbZ;`s  
    count = 0 D'Fj"&LK  
    While GetOperationCount(eID)>count pZVT:qFF  
        GetOperation eID, count, op ( o(,;  
        If op.Type="ShiftZ" Then ()Tl\  
            DeleteOperation eID,count 1" k_l.\,0  
            count=count-1 YI877T9>  
        End If C
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        count=count+1 -VC kk  
    Wend ?h$ =]  
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    'Set new z-shift /-{C,+cB  
    op.Type = "ShiftZ" F
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    op.val1 = tlens -@I+IKz  
    op.parent = parID -2D/RE7|  
    AddOperation eID, op }|KNw*h$  
    Print "Set lens thickness = " & tlens Ml"i^LR+  
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    '************************************************************************* ' F,.y6QU  
    'Lens index of refraction Ba8 s  
    '************************************************************************* ?KB+2]7m6  
    eID = FindMaterial( "Lens" ) ?Q?=I,2bP  
    GetModelMaterial eID, mat D  ,U#z  
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    mat.Nd = nlens k <EzYh  
    SetModelMaterial eID, mat >.xgo6  
    Print "Set lens index of refraction = " & nlens Y
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    '************************************************************************* pHftz-RS!  
    'Pupil diameter 6r]l8*34;  
    '************************************************************************* :j<ij]rsI  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) +46m~" ]  
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    'Adjust pupil diameter (trimming volume inner hole) }hm"49,O  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" f[XsnN2  
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    ' Adjust pupil location to just in front of the lens *LZB.84  
    parID = FindFullName( "Geometry.Arizona Eye" ) 'gaa@ !bg  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) qQ{i2D%)?f  
    count = 0 xY=%+o.?*  
    While GetOperationCount(eID)>count r8wip\[  
        GetOperation eID, count, op #~JR_oQE!  
        If op.Type="ShiftZ" Then f|r+qe  
            DeleteOperation eID,count A8zh27[w%  
            count=count-1 &tjv.t  
        End If y@'~fI!E4  
        count=count+1 E*W|>2nx]  
    Wend 'CfM'f3uu  
    op.Type = "ShiftZ" &F 3'tf?  
    op.val1 = taq-0.01 [ U`})  
    op.parent = parID wvnuE<o8  
    AddOperation eID, op .1q4Q\B<  
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    Print "Set pupil diameter = " & pupilDiam gP^p7aYwn  
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    'Update AZ Eye subassembly Description xULcS :Q  
    eID = FindFullName( "Geometry.Arizona Eye" ) .B?J@,  
    GetEntity eID, entity *?`<
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    entity.Description = "Accommodation = " & A & "D" JA]qAr  
    SetEntity eID, entity r.vezsH  
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    Update 5;:964Et  
    Print "DONE!" 'VQ mK#  
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End Sub = a54  
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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： V.?Oly  
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Accommodation = 4 Diopters ;XDGlv%  
Pupil Diameter = 4 mm TPi=!*$&  
Set aqueous humor thickness = 2.81 >$/PfyY7@#  
Set anterior lens radius = 10.4 and conic constant = -2.375869 vUD>+
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 [CAV"u)0  
Set lens thickness = 3.927 xU(yc}vw,  
Set lens index of refraction = 1.42672 *D:"I!Ho  
Set pupil diameter = 4 5n#@,V.O/  
DONE! iqAME%m