[技术]Arizona眼睛模型 [复制链接]

简介 RV(z>XM  
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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。 L,/i%-J3c  
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模型 uK5Px!  
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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。 Xlw=R2`)~  
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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. YR.'JF`C  
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光源 z+I-3v  
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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。 b2%[9)"I.  
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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。 t_Wn<)XA  
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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。 mio'm  
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视网膜的散射 Yv
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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(
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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。 jw[`\h}8  
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脚本 '=@x2`U/  
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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： Z}wAh|N-  
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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。 O7sn>uO  
余下的脚本计算与屈光度有关的所有参数。 j@2 hI,+  
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分析 ![V- e  
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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。 CmZ?uo+Y  
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脚本代码 ceCshxTU  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. b4wJnmC8  
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Dim entity As T_ENTITY 4hs4W,2!  
Dim op As T_OPERATION 'Bx7b(xqk  
Dim mat As T_MODELMATERIAL C@-JH\{\T#  
Dim A As Double ^ytd~iK8  
Dim pupilDiam As Double N_0O""d  
Dim eID As Long  2~)]E#9  
Dim parID As Long )94R\f  
Dim count As Integer e|LXH/H  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^9nM)[/C?  
Dim tlens As Double, nlens As Double o%.cQo=v*
 
Dim curv As Double, conic As Double rSk $]E]Z  
Dim ok As Long 0)NHjKP  
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Sub Main r/e&}!  
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    '用户输入对话框 M: 6cma5  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 \Mi< ROp5  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ^:0?R/A  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 82vx:*Ip!}  
        OKButton 40,91,90,21 bCF63(0  
        CancelButton 190,91,90,21 ZS-9|EA<  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 \WT
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        TextBox 220,49,40,21,.TextBox2 'default: 4 weOMYJO;8  
    End Dialog ZttL*KK  
    Dim dlg As UserDialog rW^&8E[  
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    ok = Dialog (dlg) =h)H`  
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    If ok=0 Then    'cancel button was pressed Du/s  
        Print "Execution cancelled." J}x5Ko@  
        End -=RXhE_{  
    End If DF~w20+  
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    'Assign accommodation and pupil diameter & use defaults if field left empty z 4-wvn<*  
    If dlg.TextBox1 = "" Then G\ofg  
        A = 0           'Default accommodation 0ePZxOSjD  
    Else CeQcnJU  
        A = CDbl(dlg.TextBox1) pd6d(  
    End If `uU@(  
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    If dlg.TextBox2 = "" Then r?Vob}'Pt]  
        pupilDiam = 4   'Default pupil diameter ax<0grK  
    Else Dt?Fs  
        pupilDiam = CDbl(dlg.TextBox2) 01Aa.i^d(  
    End If ^c5(MR7LD  
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    Print " " 8
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    Print "Accommodation = " & A & " Diopters" gUMUh]j  
    Print "Pupil Diameter = " & pupilDiam & " mm" n'gfB]H[  
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    ' Calculate new parameters with accommodation ZjcJYtD  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness uO6_lOT9n  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens K(p1+GHC  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens k5($b{  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens +$-a:zx`l  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 4MIVlg9  
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    tlens = 3.767 + 0.04*A                  'Lens thickness )Q8Q#
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !xvPG  
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    'Adjust parameters to account for accommodation T \AuL  
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    '************************************************************************* *
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    'Aqueous thickness (Position of Lens) , ^nUi c  
    '************************************************************************* /b*@dy  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) _)|!.r&)63  
    GetCustomElement eID, entity xv2;h4{<  
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    parID = FindFullName( "Geometry.Arizona Eye" ) HCu1vjU(]  
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    ' Delete any shift(s) in z rQWf
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    count = 0 7+ysE  
    While GetOperationCount(eID)>count 7Ctm({I-  
        GetOperation eID, count, op 0Zq"-  
        If op.Type="ShiftZ" Then n0m9|T&  
            DeleteOperation eID,count +)Ty^;+[1  
            count=count-1 FLWz7Rj  
        End If eQc!@*:8U  
        count=count+1 L}9@kjW  
    Wend %*uqtw8  
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    'Set new shift in QIw.`$H+  
    op.Type = "ShiftZ" =_XcG!"  
    op.val1 = taq /L~*FQQK>  
    op.parent = parID 9\xw}ph  
    AddOperation eID, op }'{(rU  
    Print "Set aqueous humor thickness = " & taq-0.55 WULj@ds\~
 
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    '************************************************************************* -L[K1;Xv"  
    'Radius and conic constant of anterior lens '%MIG88  
    '************************************************************************* lz(9pz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) P8EGd}2{8  
    GetConic eID, entity, curv, conic k X-AC5]  
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    SetConic eID, entity, 1/Rant, CCant g&[g?L  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Bm?Ku7}.  
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    '************************************************************************* Vlf@T  
    'Radius and conic constant of posterior lens EKt-C_)U  
    '************************************************************************* GwvxX&P  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) VjnSi  
    GetConic eID, entity, curv, conic i^> RjR  
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    SetConic eID, entity, 1/Rpost, CCpost v6rw.  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost &#;,P:.'  
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    '************************************************************************* $~-j-0 \m  
    'Lens thickness (Position of posterior lens surface) 4e(@b3y  
    '************************************************************************* EZHEJW'JnE  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0uvL,hF  
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    ' Delete any z-shift(s) >5j/4Ly  
    count = 0 spI{d!c  
    While GetOperationCount(eID)>count 3S9~rLrn?  
        GetOperation eID, count, op lL^7x  
        If op.Type="ShiftZ" Then zEGwQp<  
            DeleteOperation eID,count 07#!b~N  
            count=count-1 ~)Z`Q  
        End If ERZ[t\g)  
        count=count+1 5|b/G  
    Wend 8sg *qQ  
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    'Set new z-shift *vb)
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    op.Type = "ShiftZ" V~wmGp.e  
    op.val1 = tlens h;lnc|Hw  
    op.parent = parID `Ctj]t  
    AddOperation eID, op ?{2-,M0  
    Print "Set lens thickness = " & tlens ]+lr  
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    '************************************************************************* n5i}J/Sa2  
    'Lens index of refraction qL#R XUTP  
    '************************************************************************* Nt'5}  
    eID = FindMaterial( "Lens" ) XVfQscZe  
    GetModelMaterial eID, mat fP|\1Y?CS  
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    mat.Nd = nlens Dmw,Bi*  
    SetModelMaterial eID, mat x:xQXjJ  
    Print "Set lens index of refraction = " & nlens 3:gk:j#  
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    '************************************************************************* 71%u|k8|  
    'Pupil diameter \,Ndg*qC  
    '************************************************************************* ]'G7(Y\)f  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) pI`Ke"  
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    'Adjust pupil diameter (trimming volume inner hole) tFwlx3  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" c>g%oE  
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    ' Adjust pupil location to just in front of the lens SS`
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    parID = FindFullName( "Geometry.Arizona Eye" ) 7Tbkti;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) X]!@xlwF\  
    count = 0 hqBRh+[  
    While GetOperationCount(eID)>count !8g y)2  
        GetOperation eID, count, op RBXoU'.  
        If op.Type="ShiftZ" Then ]Oy<zU  
            DeleteOperation eID,count - \QtE}|4  
            count=count-1 -AE/,@\P  
        End If <'-me09C*  
        count=count+1 -}J8|gwwp  
    Wend R32d(2%5K  
    op.Type = "ShiftZ" [OcD#~drO  
    op.val1 = taq-0.01 DkIFvsLK  
    op.parent = parID Jj " {r{  
    AddOperation eID, op )N<!3yOz  
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    Print "Set pupil diameter = " & pupilDiam <G>PPf}  
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    'Update AZ Eye subassembly Description }>w4!  
    eID = FindFullName( "Geometry.Arizona Eye" ) \K6J{;#L  
    GetEntity eID, entity S\A[Z&k0  
    entity.Description = "Accommodation = " & A & "D" wu')Q/v  
    SetEntity eID, entity Zux2VepT  
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    Update #"_MY-  
    Print "DONE!" oB9m\o7$  
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End Sub X\%3uPQ  
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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： @XmkIm  
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Accommodation = 4 Diopters bed+Ur&  
Pupil Diameter = 4 mm R.N*G]K5  
Set aqueous humor thickness = 2.81 @Hh"Y1B  
Set anterior lens radius = 10.4 and conic constant = -2.375869 In&vh9Lw  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 /`> P|J  
Set lens thickness = 3.927 }b`*%141  
Set lens index of refraction = 1.42672 H[ q{R  
Set pupil diameter = 4 N3p3"4_]fy  
DONE! 639k&"V