[技术]Arizona眼睛模型 [复制链接]

简介 s!RA_%8/>  
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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。 zxmI/]3+/  
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模型 `]I5WTt*X  
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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。 8&[<pbN)  
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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. H?bsK~  
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光源 Z.OrHg1  
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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。 d`][1rZk  
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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。 A VG`r2T  
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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。 + d)~;I$  
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视网膜的散射  v2=!*  
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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。 r!gCh`PiK  
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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。 QgM_SY|Rj  
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脚本 &fhurzzAm  
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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： dnc!=Z89  
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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。 b'"%  
余下的脚本计算与屈光度有关的所有参数。 -"fq34v  
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分析 zk~rKQ,  
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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。 BFu9KS+@)  
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脚本代码 )L("t  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 5Cka."bQ  
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Dim entity As T_ENTITY pg`;)@  
Dim op As T_OPERATION +-137!x\q  
Dim mat As T_MODELMATERIAL B y8Tw;aL  
Dim A As Double +Z0E?,Oz  
Dim pupilDiam As Double {oeQK  
Dim eID As Long $466? oI  
Dim parID As Long .]l2)O
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Dim count As Integer 7B :aJfxM  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 1k({(\>qq  
Dim tlens As Double, nlens As Double  `.-C6!  
Dim curv As Double, conic As Double 'F~SNIay  
Dim ok As Long OyZ>R~c'B  
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Sub Main f|E'eFrFk  
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    '用户输入对话框 CU&,Kq@  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 t!C-G+It  
        TextBox 220,21,40,21,.TextBox1 'default: 0  kS9  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 $QnfpM%+=  
        OKButton 40,91,90,21 m<ruFxY  
        CancelButton 190,91,90,21 7[ji,.7  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 \H12~=p`B  
        TextBox 220,49,40,21,.TextBox2 'default: 4 rnaDo\5  
    End Dialog O,6!`\ND  
    Dim dlg As UserDialog 4w[ta?&6B  
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    ok = Dialog (dlg) :UciFIa  
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    If ok=0 Then    'cancel button was pressed go5!zSs  
        Print "Execution cancelled." =?aB@&  
        End c:TP7"vG  
    End If w!M ^p&T7  
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    'Assign accommodation and pupil diameter & use defaults if field left empty -l
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    If dlg.TextBox1 = "" Then N`MQHQ1  
        A = 0           'Default accommodation ~`.%n7  
    Else J n/=v\K@  
        A = CDbl(dlg.TextBox1) \}W.RQ^3  
    End If $ 7!GA9Bn  
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    If dlg.TextBox2 = "" Then c5pG?jr+d  
        pupilDiam = 4   'Default pupil diameter (5 hu W7v  
    Else u>#'Y+7  
        pupilDiam = CDbl(dlg.TextBox2) (#lS?+w)  
    End If OwUbm0)h^V  
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    Print " " nX'.'3  
    Print "Accommodation = " & A & " Diopters" !y.7"G*  
    Print "Pupil Diameter = " & pupilDiam & " mm" r>o6}Mx$  
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    ' Calculate new parameters with accommodation Z0KA4O$eL  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness k=}hY+/=  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Sa5y7   
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Yw0@O1Cel  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens O*7 pg  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ,fRb6s-  
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    tlens = 3.767 + 0.04*A                  'Lens thickness jL&F7itP  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction j/&7L@Y  
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    'Adjust parameters to account for accommodation ]vMft?  
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    '************************************************************************* `N+ P,  
    'Aqueous thickness (Position of Lens) Vv]mME@  
    '************************************************************************* 1)y}.y5S  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Re_.<_$  
    GetCustomElement eID, entity A[MEtI=Q J  
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    parID = FindFullName( "Geometry.Arizona Eye" ) G].Z| Z9  
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    ' Delete any shift(s) in z -L@=j  
    count = 0 }<p%PyM  
    While GetOperationCount(eID)>count w'C(? ?mH  
        GetOperation eID, count, op lx SGvvP4  
        If op.Type="ShiftZ" Then b.(^CYYQ  
            DeleteOperation eID,count I6+5mv\  
            count=count-1 fqxMTTg@  
        End If kmwFw>#  
        count=count+1 nM#\4Q[}Jh  
    Wend lUmaNZ  
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    'Set new shift in f|!
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    op.Type = "ShiftZ" 8}2 `^<U  
    op.val1 = taq o
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    op.parent = parID Ex<0@Oz  
    AddOperation eID, op c)?y3LX  
    Print "Set aqueous humor thickness = " & taq-0.55 TD'1L:mv  
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    '************************************************************************* P$Nwf,d2u  
    'Radius and conic constant of anterior lens V0>,Kxk  
    '************************************************************************* 4?`7XJ0a  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) q-'zZ#  
    GetConic eID, entity, curv, conic tP3Upw"U  
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    SetConic eID, entity, 1/Rant, CCant @L0.Z1 ).  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant *:iFhKFU  
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    '************************************************************************* B4%W,F:@  
    'Radius and conic constant of posterior lens ~_Aclm?  
    '************************************************************************* 0[^f9NZ>-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) :0/I2:  
    GetConic eID, entity, curv, conic !U@[lBW  
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    SetConic eID, entity, 1/Rpost, CCpost 0=NB[eG  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost YIfbcR5  
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    '************************************************************************* b$hQB090  
    'Lens thickness (Position of posterior lens surface) @>?&Mw\c  
    '************************************************************************* (c;$^xZK  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) .M04n\  
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    ' Delete any z-shift(s) ffdyDUzQ  
    count = 0 8D-g%Aj-  
    While GetOperationCount(eID)>count E8/P D  
        GetOperation eID, count, op {B34^H:  
        If op.Type="ShiftZ" Then =4G9ev 4  
            DeleteOperation eID,count W<t,Ivg  
            count=count-1
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        End If N G4wtDa  
        count=count+1 f -bVcWI  
    Wend P:=3;d{v  
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    'Set new z-shift
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    op.Type = "ShiftZ" tcfUhSz,I  
    op.val1 = tlens |VIBSty2d  
    op.parent = parID t<rhrW75P  
    AddOperation eID, op -YD6  
    Print "Set lens thickness = " & tlens )]'?yS"  
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    '************************************************************************* Gt'%:9r  
    'Lens index of refraction dAR):ZKq?  
    '************************************************************************* +PjH2  
    eID = FindMaterial( "Lens" ) mjfU[2  
    GetModelMaterial eID, mat 99vm7"5hQ  
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    mat.Nd = nlens ))<3+^S0V\  
    SetModelMaterial eID, mat BDpeA
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    Print "Set lens index of refraction = " & nlens V1M oW;&  
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    '************************************************************************* '6WaG hvO  
    'Pupil diameter n>{>3?  
    '************************************************************************* SBs_rhe  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) *:wu{3g}M`  
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    'Adjust pupil diameter (trimming volume inner hole) p "u5wJ_  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" .xS}/^8iD  
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    ' Adjust pupil location to just in front of the lens vk&C'&uV9@  
    parID = FindFullName( "Geometry.Arizona Eye" ) b k 30d  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) k1W q$KCwG  
    count = 0 <rNCb;  
    While GetOperationCount(eID)>count 1 %K^(J;  
        GetOperation eID, count, op [;%qxAB/_  
        If op.Type="ShiftZ" Then #)z_TM07P  
            DeleteOperation eID,count "*a^_tsT?i  
            count=count-1 <GT&q <4w  
        End If SnRk` 5t  
        count=count+1 j'
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    Wend N^H~VG&D(  
    op.Type = "ShiftZ" 4
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    op.val1 = taq-0.01 BNL Q]  
    op.parent = parID a!vF;J-Zqa  
    AddOperation eID, op q3n(Z  
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    Print "Set pupil diameter = " & pupilDiam >8\EdN59{  
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    'Update AZ Eye subassembly Description |p}qK Fdi  
    eID = FindFullName( "Geometry.Arizona Eye" ) 0x*L
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    GetEntity eID, entity 0P_q
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    entity.Description = "Accommodation = " & A & "D" 3!ZndWSHV  
    SetEntity eID, entity l@Uo4b^4x  
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    Update :_X9x{  
    Print "DONE!" M:YtW5{  
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End Sub ju~js  
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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： T*e>_\Tx  
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Accommodation = 4 Diopters n$&xVaF|  
Pupil Diameter = 4 mm [oqb@J2  
Set aqueous humor thickness = 2.81 ~H`~&?  
Set anterior lens radius = 10.4 and conic constant = -2.375869 )%FRBO]  
Set posterior lens radius = -4.424557 and conic constant = -3.081019
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Set lens thickness = 3.927 dz3chy,3  
Set lens index of refraction = 1.42672 os9X)G  
Set pupil diameter = 4 9M8n  
DONE! J0K25w