[技术]Arizona眼睛模型 [复制链接]

简介 o6$4/I  
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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。 Bj7gQ%>H4  
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模型 5h;+Ky!I  
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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。 ;J7F J3n  
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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. .9.2Be  
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光源 av~5l4YL  
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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。 %j7XEh<'  
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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。 'F3)9&M  
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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。 7F'`CleU  
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视网膜的散射
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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。 7x<i :x3  
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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。 k?7 X3/O  
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脚本 ccL~#c0P7  
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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： {%C7EAq*  
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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。 PsZ >P|e1  
余下的脚本计算与屈光度有关的所有参数。 3g6j?yYqb  
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分析 y\x+  
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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。 ?C/Te)  
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脚本代码 =yy5D$\  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. b3VS\[p  
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Dim entity As T_ENTITY l\n@cQR  
Dim op As T_OPERATION hh[jN7K  
Dim mat As T_MODELMATERIAL k]I0o)+O.  
Dim A As Double wT{nu[=GH*  
Dim pupilDiam As Double 5v6Eii:  
Dim eID As Long y.Z?LCd<  
Dim parID As Long n-@j5w+k4  
Dim count As Integer o-Ga3i 8  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double NG6& :4!  
Dim tlens As Double, nlens As Double Q6r7.pk"SU  
Dim curv As Double, conic As Double RG4sQ0
 
Dim ok As Long L~KM=[cn  
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Sub Main _x5 3g A  
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    '用户输入对话框 W='>:H  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 lMbAs.!  
        TextBox 220,21,40,21,.TextBox1 'default: 0 f^.AD-  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ::/j$bL  
        OKButton 40,91,90,21 k Zq!&  
        CancelButton 190,91,90,21 2TA*m{\Hr  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 /ID?DtJ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 %p0xM  
    End Dialog v 7x:dcV  
    Dim dlg As UserDialog x UD-iSY  
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    ok = Dialog (dlg) PKzyV ;  
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    If ok=0 Then    'cancel button was pressed 2Roc|)-47  
        Print "Execution cancelled." }O4
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        End TG5XSy  
    End If .>IhN 5  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ,kn">k9  
    If dlg.TextBox1 = "" Then Ez-[ )44/  
        A = 0           'Default accommodation .uk>QMs1  
    Else 4tS.G  
        A = CDbl(dlg.TextBox1) =>! Y{: y(  
    End If I}vmU^Y>  
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    If dlg.TextBox2 = "" Then BV[5}  
        pupilDiam = 4   'Default pupil diameter B[4KX  
    Else =Yt R`  
        pupilDiam = CDbl(dlg.TextBox2) ]V#M%0:Q82  
    End If [n$BRk|  
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    Print " " i|m3mcI%2  
    Print "Accommodation = " & A & " Diopters" iS<I0\D  
    Print "Pupil Diameter = " & pupilDiam & " mm" 5x>}O3Q_  
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    ' Calculate new parameters with accommodation \9g+^vQ
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness jE/AA!DC#  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens wD]/{
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens i0$kit  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens CLJ;<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ch3jxgQY  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Yn G_m]  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ]f({`&K5  
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    'Adjust parameters to account for accommodation 
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    '************************************************************************* ]@Uq=?%  
    'Aqueous thickness (Position of Lens) A'&K/)Z  
    '************************************************************************* HEM9E&rL  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) aiu5}%U  
    GetCustomElement eID, entity E`uY1B[c  
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    parID = FindFullName( "Geometry.Arizona Eye" ) _c_[C*T]  
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    ' Delete any shift(s) in z ]h %Wiw  
    count = 0 PIwFF}<(  
    While GetOperationCount(eID)>count AGYc |;  
        GetOperation eID, count, op &H`jL4S  
        If op.Type="ShiftZ" Then "pRtczxOgR  
            DeleteOperation eID,count D5*q7A6  
            count=count-1 -3=#u_  
        End If c:o]d)S  
        count=count+1 !*%WuyCgr4  
    Wend F6{bjv2A  
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    'Set new shift in n74V|b6W  
    op.Type = "ShiftZ" v63"^%LX  
    op.val1 = taq Qh'ATo  
    op.parent = parID ;k>&FWEG  
    AddOperation eID, op m1Mt#@,$  
    Print "Set aqueous humor thickness = " & taq-0.55 @3C>BLI8+  
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    '************************************************************************* Gf
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    'Radius and conic constant of anterior lens 7B\Vs-d  
    '************************************************************************* .Lsavpo  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) =aBctd:eX`  
    GetConic eID, entity, curv, conic NP/Gn6fr  
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    SetConic eID, entity, 1/Rant, CCant UZJCvfi  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant &N\jG373  
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    '************************************************************************* Xy$3VU*  
    'Radius and conic constant of posterior lens li}1S  
    '************************************************************************* )E-inHD /  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 9{5&^RbCp  
    GetConic eID, entity, curv, conic 2;DuHO1  
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    SetConic eID, entity, 1/Rpost, CCpost |6K+E6H  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost @c;|G$E@3  
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    '************************************************************************* YW( Qmo7  
    'Lens thickness (Position of posterior lens surface) V`XNDNJ:  
    '************************************************************************* e'~J,(fB  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) eOs)_?}  
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    ' Delete any z-shift(s) 6sx'S?Qa*  
    count = 0 d\R,Q  
    While GetOperationCount(eID)>count { + Zd*)M[  
        GetOperation eID, count, op S/e2P|}  
        If op.Type="ShiftZ" Then "J[K 3  
            DeleteOperation eID,count j/f?"VEr  
            count=count-1 ?&63#B,iZ  
        End If j/_s"}m{  
        count=count+1 jU9$Ehg I  
    Wend -y8`yHb_  
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    'Set new z-shift VFURAYS  
    op.Type = "ShiftZ" V9{]OV%  
    op.val1 = tlens Kgi<UkFP  
    op.parent = parID +#lM  
    AddOperation eID, op $Bs {u=+w  
    Print "Set lens thickness = " & tlens iw8yb;|z;A  
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    '************************************************************************* ,y 2$cO_>  
    'Lens index of refraction i]6`LqlO  
    '************************************************************************* P3)Nl^/  
    eID = FindMaterial( "Lens" ) iS WU'K  
    GetModelMaterial eID, mat #><.oreXq  
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    mat.Nd = nlens &U5{Hm9Ynr  
    SetModelMaterial eID, mat QgU8s'e  
    Print "Set lens index of refraction = " & nlens %S*{9hm/  
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    '************************************************************************* :y%/u%L  
    'Pupil diameter Q@<S[Qh[.  
    '************************************************************************* @|63K)Xy  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $JJrSwR<h  
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    'Adjust pupil diameter (trimming volume inner hole) jr /pj?  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Y2ZT.l  
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    ' Adjust pupil location to just in front of the lens bF"G[pD  
    parID = FindFullName( "Geometry.Arizona Eye" ) w$z}r  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) UEM(@zD]  
    count = 0 #LL?IRH9^  
    While GetOperationCount(eID)>count Mc09ES  
        GetOperation eID, count, op %l}D.ml  
        If op.Type="ShiftZ" Then /%}*Xh  
            DeleteOperation eID,count JEahGzO  
            count=count-1 b&~4t/Vq  
        End If `\gnl'  
        count=count+1 l_P-j96WD  
    Wend #fM#p+v  
    op.Type = "ShiftZ" \?0&0;5  
    op.val1 = taq-0.01 / ';0H_  
    op.parent = parID ypKUkH/  
    AddOperation eID, op 6y+Kjd/D  
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    Print "Set pupil diameter = " & pupilDiam 7\$qFF-y  
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    'Update AZ Eye subassembly Description ysxb?6  
    eID = FindFullName( "Geometry.Arizona Eye" ) V5sg#|
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    GetEntity eID, entity %k-3?%&8  
    entity.Description = "Accommodation = " & A & "D" \O*-#}~\  
    SetEntity eID, entity Zhh2v>QOy  
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    Update ~P8tUhff
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    Print "DONE!" ewa wL"  
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End Sub s \;"X  
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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： yj;sSRT  
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Accommodation = 4 Diopters !MYSfPdS  
Pupil Diameter = 4 mm cC=[Saatsf  
Set aqueous humor thickness = 2.81
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Set anterior lens radius = 10.4 and conic constant = -2.375869 'Jt]7;04p  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 tZ=E')!\  
Set lens thickness = 3.927 Gn|F`F  
Set lens index of refraction = 1.42672 uD1e!oU  
Set pupil diameter = 4 4L ;% h  
DONE! +Z7th7W/,