[技术]Arizona眼睛模型 [复制链接]

简介 [jx0-3s:X  
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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。 "+"{+k5t  
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模型 ~IVd vm7  
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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。 -!qu"A:  
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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. hi=XYC,  
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光源 ^[:9fs  
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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。 ?q2j3e[>  
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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。 $Byj}^;1  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。
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视网膜的散射 FaT
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 }Y(]6$uS  
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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。 w^k;D,h  
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脚本 -a Gcf]6  
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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： '&O/g<Z}q  
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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。 YKZrEP4^  
余下的脚本计算与屈光度有关的所有参数。 ivgpS5 M`Y  
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分析 *="8?Z  
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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。 v<\A%  
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脚本代码 +Z2MIC|Ud  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. DH DZ_t:  
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Dim entity As T_ENTITY z7.|fE)<6  
Dim op As T_OPERATION EY`H}S!xy  
Dim mat As T_MODELMATERIAL jg 2qGC  
Dim A As Double 7DW]JK l  
Dim pupilDiam As Double pqM~l&  
Dim eID As Long s}&bJ"!Z  
Dim parID As Long m^%|ZTrwN7  
Dim count As Integer Z{IUy  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double NW|f7 ItX  
Dim tlens As Double, nlens As Double QlFZO4 P3|  
Dim curv As Double, conic As Double <BWkUZz\P|  
Dim ok As Long rRES8/  
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Sub Main Mkp/0|Q*  
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    '用户输入对话框 <O?y-$~  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 FFhtj(hVgc  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ;wiao(t>4N  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1PaUI#X"2F  
        OKButton 40,91,90,21 ^da44Qqu  
        CancelButton 190,91,90,21 HC {XX>F^  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 A|#`k{+1-  
        TextBox 220,49,40,21,.TextBox2 'default: 4 5\mTr)\R  
    End Dialog C;AA/4Ib  
    Dim dlg As UserDialog X#xFFDzN  
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    ok = Dialog (dlg) pi(-A  
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    If ok=0 Then    'cancel button was pressed js^ ,(CS  
        Print "Execution cancelled." A% Q!^d  
        End [@<sFP;g  
    End If Op.8a`XLt&  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 05Fz@31~  
    If dlg.TextBox1 = "" Then VO3pm
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        A = 0           'Default accommodation d|9b~_::V  
    Else JE5  
        A = CDbl(dlg.TextBox1) $
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    End If H?1xjY9sl  
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    If dlg.TextBox2 = "" Then I-D^>\k+  
        pupilDiam = 4   'Default pupil diameter zo{/'BnU  
    Else I:&/`K4,x,  
        pupilDiam = CDbl(dlg.TextBox2) 4nfu6Dq  
    End If +.B<Hd  
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    Print " " P`4]-5gE  
    Print "Accommodation = " & A & " Diopters" Z#d&|5Xj  
    Print "Pupil Diameter = " & pupilDiam & " mm" zr v]  
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    ' Calculate new parameters with accommodation h!@|RW&}qX  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness mM.*b@d-  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens j*@l"V>~  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 2Q7R6*<N:  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens <oKGD50#  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens #v#<itfFH  
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    tlens = 3.767 + 0.04*A                  'Lens thickness }UJv[  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction e<7.y#L  
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    'Adjust parameters to account for accommodation ]=rht9),"  
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    '************************************************************************* 1Q;}zHd  
    'Aqueous thickness (Position of Lens) z't??6  
    '************************************************************************* 9Gy  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4!Z5og1kn  
    GetCustomElement eID, entity "]'?a$\ky:  
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    parID = FindFullName( "Geometry.Arizona Eye" ) -\ZcOXpMx=  
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    ' Delete any shift(s) in z r0t^g9K0  
    count = 0 y4Z&@,_{  
    While GetOperationCount(eID)>count mE O\r|A  
        GetOperation eID, count, op o56`  
        If op.Type="ShiftZ" Then n8=5-7UT  
            DeleteOperation eID,count TlAR.cV  
            count=count-1 Xdi:1wW@p  
        End If c0c|z Ym  
        count=count+1 d\MLOXnLq;  
    Wend WH ?}~u9  
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    'Set new shift in
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    op.Type = "ShiftZ" ~AYN  
    op.val1 = taq a8u9aEB  
    op.parent = parID :.(;<b<\  
    AddOperation eID, op ?1L
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    Print "Set aqueous humor thickness = " & taq-0.55 GWsE;  
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    '************************************************************************* 4${jr\q]  
    'Radius and conic constant of anterior lens V$0dtvGvH  
    '************************************************************************* (npj_s!.C)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) .)1_Ew  
    GetConic eID, entity, curv, conic tqAd$:L  
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    SetConic eID, entity, 1/Rant, CCant hLJM%on  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant }(a+aHH  
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    '************************************************************************* 6s,uXn  
    'Radius and conic constant of posterior lens a{!QOX%K  
    '************************************************************************* PFUO8>!pA\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) GdB.4s^  
    GetConic eID, entity, curv, conic VxP&j0M>  
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    SetConic eID, entity, 1/Rpost, CCpost V)Z70J<'  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost EM>}0V  
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    '************************************************************************* I%|>2}-_U  
    'Lens thickness (Position of posterior lens surface) mw_Ew]&  
    '************************************************************************* Y|8vO  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z*G(5SqUh"  
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    ' Delete any z-shift(s) (E,T#uc{  
    count = 0 R+gz<H.Q  
    While GetOperationCount(eID)>count B?VhIP e  
        GetOperation eID, count, op dEBcfya  
        If op.Type="ShiftZ" Then oJ#
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            DeleteOperation eID,count |t$Ma'P  
            count=count-1 Zmbfq8K  
        End If .q+0pj  
        count=count+1 CctJFcEZ  
    Wend &A#~)i5gF  
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    'Set new z-shift `1:{0p2q  
    op.Type = "ShiftZ" (EPsTox  
    op.val1 = tlens lKk/p^:  
    op.parent = parID ?` SUQm  
    AddOperation eID, op `y#UJYXQE  
    Print "Set lens thickness = " & tlens d1[ZHio2c?  
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    '************************************************************************* s3Cc;#  
    'Lens index of refraction UMX@7a,[3  
    '************************************************************************* 0M\D[mg  
    eID = FindMaterial( "Lens" ) r1RGTEkD  
    GetModelMaterial eID, mat !3T&4t  
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    mat.Nd = nlens G "P4-  
    SetModelMaterial eID, mat ybp 
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    Print "Set lens index of refraction = " & nlens iQ{G(^sZN  
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    '************************************************************************* r'gOVi4t1*  
    'Pupil diameter Z|}G6]h  
    '************************************************************************* `~eUee3b.~  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) |7x\m t  
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    'Adjust pupil diameter (trimming volume inner hole) I%urz!CNE*  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" e{Z &d  
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    ' Adjust pupil location to just in front of the lens 1;VHM'  
    parID = FindFullName( "Geometry.Arizona Eye" ) $.]l!cmi%Q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Ar~"R4!  
    count = 0 ]l8^KX'  
    While GetOperationCount(eID)>count -W>'^1cR  
        GetOperation eID, count, op b86}% FM  
        If op.Type="ShiftZ" Then F2X0%te  
            DeleteOperation eID,count Z0l+1iMx  
            count=count-1 ?6'rBH/w  
        End If [=~pe|8:  
        count=count+1 #:SNHM^><  
    Wend _UuC,Pl3  
    op.Type = "ShiftZ" 47J5oPT2'  
    op.val1 = taq-0.01 7`u$  
    op.parent = parID v0L\0&+  
    AddOperation eID, op 4*$G & TX  
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    Print "Set pupil diameter = " & pupilDiam NO :a;  
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    'Update AZ Eye subassembly Description m8.U &0  
    eID = FindFullName( "Geometry.Arizona Eye" ) y+7PwBo%e  
    GetEntity eID, entity <tioJG{OT  
    entity.Description = "Accommodation = " & A & "D" u]OW8rc  
    SetEntity eID, entity ~g.$|^,.O/  
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    Update :,)lm.}]t  
    Print "DONE!" ({o'd=nO  
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End Sub /&4U6a  

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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： 0V?F'<qy  
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Accommodation = 4 Diopters K<>sOWZ'S  
Pupil Diameter = 4 mm {p,]oOq\  
Set aqueous humor thickness = 2.81 \QB;Ja
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Set anterior lens radius = 10.4 and conic constant = -2.375869 0iJue&  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 33}oO,}t,  
Set lens thickness = 3.927 C`q@X(_  
Set lens index of refraction = 1.42672 A~mum+[5  
Set pupil diameter = 4 G+F:
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DONE! sq'Pyz[[