[技术]Arizona眼睛模型 [复制链接]

简介 T,5]EHe
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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。 ](B+ilr   
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模型 <AzvVSA,  
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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。 3g)pLW  
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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.  >.0
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光源 y&UcTE2;%(  
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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。 <-FAF:6$@@  
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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。 F0qGkMs|f  
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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。 R8sj>.I9j  
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视网膜的散射 1=}+NK!  
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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。 !Qy%sY  
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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。 !#Ub*qY1Z  
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脚本 -XRn%4EX?  
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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： B<%cqz@  
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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。 AY<(`J{  
余下的脚本计算与屈光度有关的所有参数。 MAb*4e#  
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分析 VKqIFM1b  
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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。 g0O~5.f  
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脚本代码 Se{x-vn?p  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. :7>oFz  
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Dim entity As T_ENTITY |Tv}leJF  
Dim op As T_OPERATION 'guXdX]Gu  
Dim mat As T_MODELMATERIAL u
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Dim A As Double !?)ky `S3  
Dim pupilDiam As Double >>bsr#aJ  
Dim eID As Long
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Dim parID As Long oN({X/P2j  
Dim count As Integer v]{F.N  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double VW&EdrR,S  
Dim tlens As Double, nlens As Double 6Ft?9 B(F:  
Dim curv As Double, conic As Double }$%j}F{  
Dim ok As Long EmG':K(  
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Sub Main C-)mP- |8  
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    '用户输入对话框 (w[#h9j  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 b'r</ncZ  
        TextBox 220,21,40,21,.TextBox1 'default: 0 2i0 .x  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Cf
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        OKButton 40,91,90,21 UlP2VKM1&  
        CancelButton 190,91,90,21 00SYNG!  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ^#( B4l!  
        TextBox 220,49,40,21,.TextBox2 'default: 4 8FT]B/^&m  
    End Dialog  A:b(@'h  
    Dim dlg As UserDialog f |%II,!3  
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    ok = Dialog (dlg) :Oiz|b(  
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    If ok=0 Then    'cancel button was pressed (fA>@
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        Print "Execution cancelled." #)r^ZA&E  
        End Sy@)Q[A  
    End If [g<Y,0,J  
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    'Assign accommodation and pupil diameter & use defaults if field left empty lQl!TW"aO  
    If dlg.TextBox1 = "" Then =Gv*yR*]t  
        A = 0           'Default accommodation ~7=eHU.@  
    Else zsM2R"[X  
        A = CDbl(dlg.TextBox1) ThvgYv--B  
    End If / f5q9sp8  
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    If dlg.TextBox2 = "" Then 9epMw-)k  
        pupilDiam = 4   'Default pupil diameter ej,)<*  
    Else mO=A50_&,Q  
        pupilDiam = CDbl(dlg.TextBox2) q@Aw]Kh  
    End If \E(^<Af  
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    Print " " ?kIyo  
    Print "Accommodation = " & A & " Diopters" )-\C{>  
    Print "Pupil Diameter = " & pupilDiam & " mm" x{O) n  
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    ' Calculate new parameters with accommodation 4aP 96  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness m]+~F_/  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens T>hrKn.!D:  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens tVv/G~(  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens bN\;m^xfu  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens A`~R\j  
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    tlens = 3.767 + 0.04*A                  'Lens thickness v,'k2H  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 2YDD`:R  
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    'Adjust parameters to account for accommodation =Vm3f^  
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    '************************************************************************* a&Qr7tTY"  
    'Aqueous thickness (Position of Lens) =2t=Zyp0Y  
    '************************************************************************* p*j>s\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7W'&v+\  
    GetCustomElement eID, entity ZO!h!2*  
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    parID = FindFullName( "Geometry.Arizona Eye" ) -5oYGLS$y3  
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    ' Delete any shift(s) in z 7Ll?#eun  
    count = 0 -%Rw2@vU  
    While GetOperationCount(eID)>count 6B|OKwL  
        GetOperation eID, count, op o~<jayqU  
        If op.Type="ShiftZ" Then IL`LIJ:O  
            DeleteOperation eID,count znB+RiV8  
            count=count-1 \gu8 ~zK  
        End If 7}I';>QH  
        count=count+1 :>}7^1I  
    Wend 6oa>\PDy   
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    'Set new shift in (*M0'5  
    op.Type = "ShiftZ" w~_ycY.e  
    op.val1 = taq b<!' WpY-  
    op.parent = parID \2!.  
    AddOperation eID, op qnHjwMi  
    Print "Set aqueous humor thickness = " & taq-0.55 cTz@ga;!mI  
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    '************************************************************************* oxBTm|j7  
    'Radius and conic constant of anterior lens YZ]}l%e  
    '************************************************************************* 8[.&ca/[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) S}fQis  
    GetConic eID, entity, curv, conic S\]9mHJI  
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    SetConic eID, entity, 1/Rant, CCant (t){o>l  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ;HBKOe_3  
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    '************************************************************************* :f:&B8  
    'Radius and conic constant of posterior lens HE{UgU:tY  
    '************************************************************************* dWi<U4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) yZ!~m3Q  
    GetConic eID, entity, curv, conic _k :BY  
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    SetConic eID, entity, 1/Rpost, CCpost +1I7K|M  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [ #ih o(/  
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    '************************************************************************* 3-E
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    'Lens thickness (Position of posterior lens surface) r;)31Tg  
    '************************************************************************* |Eh2#K0x4G  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~3-"1E>Rgy  
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    ' Delete any z-shift(s) W
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    count = 0 *P5\T4!+d  
    While GetOperationCount(eID)>count k]C k%[d  
        GetOperation eID, count, op 8KN3|)  
        If op.Type="ShiftZ" Then s?s,wdp  
            DeleteOperation eID,count .%dGSDru  
            count=count-1 `\|@w@f|;  
        End If l]~9BPsR  
        count=count+1 x4PzP  
    Wend }A]eC  
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    'Set new z-shift N34-z|"q  
    op.Type = "ShiftZ" WVsj  
    op.val1 = tlens ~N
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    op.parent = parID ev0>j4Q  
    AddOperation eID, op IA&V?{OE@I  
    Print "Set lens thickness = " & tlens qdy(C^(fa  
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    '************************************************************************* *59|  
    'Lens index of refraction `1n^~  
    '************************************************************************* Z m%,L$F*L  
    eID = FindMaterial( "Lens" ) gvc/Z <Y  
    GetModelMaterial eID, mat d>mT+{3  
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    mat.Nd = nlens @)0  
    SetModelMaterial eID, mat { `Z~T&}~T  
    Print "Set lens index of refraction = " & nlens -"S94<Y  
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    '************************************************************************* y$bY 8L  
    'Pupil diameter 5-ED\-  
    '************************************************************************* ;du},>T$n  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) u{va2n/  

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    'Adjust pupil diameter (trimming volume inner hole) l`l6Y>c*]  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" [0105l5  
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    ' Adjust pupil location to just in front of the lens N$#~&  
    parID = FindFullName( "Geometry.Arizona Eye" ) t2vm&jk  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 2}XRqa.|  
    count = 0 Cse`MP  
    While GetOperationCount(eID)>count fMUh\u3  
        GetOperation eID, count, op ! [1aP,  
        If op.Type="ShiftZ" Then *k;bkd4x  
            DeleteOperation eID,count P7zUf  
            count=count-1 +TA~RCd  
        End If @[?ZwzY:9  
        count=count+1 vf@j d}?  
    Wend !W8=\:D[  
    op.Type = "ShiftZ" kr~n5WiAZ  
    op.val1 = taq-0.01 64#Ri!RR}  
    op.parent = parID E9>z.vV   
    AddOperation eID, op u-y?i`  

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    Print "Set pupil diameter = " & pupilDiam n"aF#HR?0d  
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    'Update AZ Eye subassembly Description kvbW^pl  
    eID = FindFullName( "Geometry.Arizona Eye" ) mD.6cV  
    GetEntity eID, entity TfkGkVR  
    entity.Description = "Accommodation = " & A & "D" vV$t`PEY  
    SetEntity eID, entity 8x)i{>#i  
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    Update 6;:D!},'c  
    Print "DONE!" I}o} #OJ  
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End Sub 0Fon`3(^\  
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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： 4U}J?EB?K  
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Accommodation = 4 Diopters %{4U\4d@'  
Pupil Diameter = 4 mm 4Eu'_
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Set aqueous humor thickness = 2.81 Q|{b8K  
Set anterior lens radius = 10.4 and conic constant = -2.375869 "= %"@"<)  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ggrYf*  
Set lens thickness = 3.927 F)X`CG ;t  
Set lens index of refraction = 1.42672 Kw;gQk~R!  
Set pupil diameter = 4 <z2.A/L  
DONE! / [49iIzC