[技术]Arizona眼睛模型 [复制链接]

简介 2$kB^g!:o  
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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。 {hJCn*m_   
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模型 xZ)K#\  
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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。 T7"QwA  
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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. %3~miP  
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光源 7%EIn9P  
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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。 K}cA%Y  
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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。 Pg8boN]}  
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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。 _hyqHvP  
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视网膜的散射 ?wPTe^Qtv  
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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。 i KQj[%O  
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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。 (kB  
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脚本 5hy7}*dR  
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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： [KYq01cj  
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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。 H @k}  
余下的脚本计算与屈光度有关的所有参数。 L`K)mCr  
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分析 *5BVL_:~J  
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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。 (^FMm1@T  
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脚本代码 XrTc5V  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. JUA%l  
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Dim entity As T_ENTITY yW1N&$n  
Dim op As T_OPERATION ,&4 [`d  
Dim mat As T_MODELMATERIAL @H$am  
Dim A As Double PSu]I?WF  
Dim pupilDiam As Double jrN 5l1np  
Dim eID As Long :KvZP:T  
Dim parID As Long EeQ8Uxb7  
Dim count As Integer *vRHF1)L  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double NiVLx_<Pr'  
Dim tlens As Double, nlens As Double ufR>*)_+  
Dim curv As Double, conic As Double #S/~1{  
Dim ok As Long j -o  
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Sub Main y@*4*4
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    '用户输入对话框 jWxa [>  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 [= E=H*j  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ;WN%tI)  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 dfVI*5[Z  
        OKButton 40,91,90,21 V4"o.G3\o  
        CancelButton 190,91,90,21 e[T3,2C  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 @]X!#&2>  
        TextBox 220,49,40,21,.TextBox2 'default: 4 TTj] _R{n  
    End Dialog nY1PRX\  
    Dim dlg As UserDialog Bq~S=bAB>R  
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    ok = Dialog (dlg) K6B6@  
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    If ok=0 Then    'cancel button was pressed ~8k`~t!
 
        Print "Execution cancelled." 5ip ZdQ^  
        End 78xiT  
    End If %iIr %P?  
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    'Assign accommodation and pupil diameter & use defaults if field left empty P!9-!+F"  
    If dlg.TextBox1 = "" Then `ZC -lAY  
        A = 0           'Default accommodation e jk?If 07  
    Else C;ha2UV0H  
        A = CDbl(dlg.TextBox1) }o GMF~  
    End If _%rkN0-(a  
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    If dlg.TextBox2 = "" Then O&.gc p!  
        pupilDiam = 4   'Default pupil diameter d<\
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    Else I %1P:-  
        pupilDiam = CDbl(dlg.TextBox2) 
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    End If fH
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    Print " " yyVJb3n5:!  
    Print "Accommodation = " & A & " Diopters" bsc b
 
    Print "Pupil Diameter = " & pupilDiam & " mm" &{M-<M  
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    ' Calculate new parameters with accommodation 9WoTo ,q  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness G7-.d/8|^  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens $Ovq}Rexc  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens W7V#G(cpU  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens P)=$0kR3  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens LwQYO'X  
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    tlens = 3.767 + 0.04*A                  'Lens thickness G\f:H%[5[  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction bq5?fPBrq  
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    'Adjust parameters to account for accommodation z
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    '************************************************************************* F+Hmp\rM#  
    'Aqueous thickness (Position of Lens) ;x{J45^  
    '************************************************************************* ~|wh/]{b9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) kf",/?s2Z  
    GetCustomElement eID, entity [py/\zkn  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 8`w#)6(V  
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    ' Delete any shift(s) in z -Ze2]^#dl  
    count = 0 a,*|*Cv  
    While GetOperationCount(eID)>count c30kb  
        GetOperation eID, count, op @2A&eLwLH  
        If op.Type="ShiftZ" Then N*
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            DeleteOperation eID,count [ 3SbWwg  
            count=count-1 ?0+J"FH# W  
        End If 6k\8ulHw  
        count=count+1 }cy<$=c#E_  
    Wend %Zu+=IZ  
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    'Set new shift in .TRp74  
    op.Type = "ShiftZ" iJ`v3PP  
    op.val1 = taq =G/`r!r*0I  
    op.parent = parID /u'
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    AddOperation eID, op 3:P "6mN  
    Print "Set aqueous humor thickness = " & taq-0.55 X9uYqvP\(  
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    '************************************************************************* +Xr87x;  
    'Radius and conic constant of anterior lens 0(!=N1l  
    '************************************************************************* u#34mg..  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) mt3j$r{_  
    GetConic eID, entity, curv, conic &f>1/"lnd\  
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    SetConic eID, entity, 1/Rant, CCant 2Yd;#i)  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant h)C`w'L  
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    '************************************************************************* =dI2j@}c  
    'Radius and conic constant of posterior lens T .L>PL?=  
    '************************************************************************* #v4q:&yKf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Z0%Qy+%  
    GetConic eID, entity, curv, conic > 1&_-  
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    SetConic eID, entity, 1/Rpost, CCpost Kkds^v6  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost !"x&tF  
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    '************************************************************************* Bso3Z ^X.  
    'Lens thickness (Position of posterior lens surface) .Cf`D tK  
    '************************************************************************* !|S{e^WhbU  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) L9)
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    ' Delete any z-shift(s) ;v1&Rs  
    count = 0 h/n&&J  
    While GetOperationCount(eID)>count Vnq&lz%QqC  
        GetOperation eID, count, op |\~!oN  
        If op.Type="ShiftZ" Then [P23.`G~J  
            DeleteOperation eID,count ({AqL#x`u  
            count=count-1 PG/xX H  
        End If ep2#a#&'  
        count=count+1 a5xp[TlXn.  
    Wend 5}t}Wc8  
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    'Set new z-shift nXOJ  
    op.Type = "ShiftZ" 6>Szxkz  
    op.val1 = tlens w
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    op.parent = parID I=I'O?w  
    AddOperation eID, op (AnM_s
 
    Print "Set lens thickness = " & tlens XZFM|=%X  
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    '************************************************************************* g4 |s9RMD  
    'Lens index of refraction eO:wx.PW  
    '************************************************************************* #{kwl|c  
    eID = FindMaterial( "Lens" ) .3.oan*i  
    GetModelMaterial eID, mat \L:;~L/  
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    mat.Nd = nlens 3o=K?eOdg  
    SetModelMaterial eID, mat .UuCTH;6`  
    Print "Set lens index of refraction = " & nlens IPhV|7
 
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    '************************************************************************* "NamP\hj  
    'Pupil diameter ]%PQ3MT.  
    '************************************************************************* P+~{q.|._c  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) }t[?g)"M#-  
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    'Adjust pupil diameter (trimming volume inner hole) SGREpOlJ+  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" #X(KW&;m  
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    ' Adjust pupil location to just in front of the lens Rx22W:S=C.  
    parID = FindFullName( "Geometry.Arizona Eye" ) Q~A25Jf.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) S6r$n  
    count = 0 ;r_YEPlZ  
    While GetOperationCount(eID)>count Wa{>R2h\  
        GetOperation eID, count, op xmEmdOoD  
        If op.Type="ShiftZ" Then y[s* %yP3l  
            DeleteOperation eID,count Ck|3DiRQ  
            count=count-1 ~EVD NnHEr  
        End If f"j"ZM{~U  
        count=count+1 y%21`y&Os  
    Wend xi.L?"^/!  
    op.Type = "ShiftZ" MW^,l=kqW)  
    op.val1 = taq-0.01 SG{> t*E  
    op.parent = parID #mNM5(o  
    AddOperation eID, op ,[l
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    Print "Set pupil diameter = " & pupilDiam Q}a 1P8?S  
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    'Update AZ Eye subassembly Description ?]'Rz\70  
    eID = FindFullName( "Geometry.Arizona Eye" ) 5{Xld,zw  
    GetEntity eID, entity q89#Ftkt  
    entity.Description = "Accommodation = " & A & "D" "-'w,g  
    SetEntity eID, entity 4|Dxyb>pS  
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    Update MjAF&bD^  
    Print "DONE!" J?WT  
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End Sub .`OyC'  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： q^ {Xn-G  
dsKEWZ =  
Accommodation = 4 Diopters p4 #U:_  
Pupil Diameter = 4 mm 30(O]@f~  
Set aqueous humor thickness = 2.81 7(m4,l+(  
Set anterior lens radius = 10.4 and conic constant = -2.375869 HB+\2jEE  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 )p&FDK#ob=  
Set lens thickness = 3.927 )S
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Set lens index of refraction = 1.42672 `zNvZm-E  
Set pupil diameter = 4 E>tlY&0[$  
DONE! K<O1PrC