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2016-02-24 12:53 |
FRED运用:Arizona眼睛模型
简介 U-Af7qO 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。 3q'K5}
_ "_nX5J9 模型 c+szU}(f6( ,3w I~j= 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。 >[Xm|A# pu\b`3C(
Table 1. AZ眼睛模型的定义 [attachment=67931] |x1$b7 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. keT?,YI 7ZF}0K$^B 光源 qJ\X~5{ iP~sft6 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。 U3mXm?f umJay/> 1k!D0f3qb
[attachment=67932] 图1. 光源和提示信息使用 bcq@N 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。 Zr\2BOcc.l 1t0bUf;(M 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。 o&CghF R!sNg
[attachment=67933] 图2. 字母F光源的设定方法光 <2n'}&F j FgZ}Xp
[attachment=67934] 图3. 字母F在视网膜上位置点列图 RM)1*l`!E 视网膜的散射 +ckMT3 z
VnIr<!8_ 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。 MNkKy(Za \U==f&G?J \V._Z>]
[attachment=67935] 图4. 视网膜朗伯散射设定 #uQrJh1o8 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。 x*:n4FZ7b HkW/G[7x& |c<XSX?ir
[attachment=67936] 图5. 视网膜重点采样规格设定 7^c2e*S 脚本 RI?NB6U FL59 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: g* %bzfk=| |__d 8a
[attachment=67937] 图6. 用户对话框的创建与编辑 ERk kSTp
[attachment=67938] 图7. 用户对话框编辑器 K3Huu!Tr 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。 Q%rVo4M#2 余下的脚本计算与屈光度有关的所有参数。 7TP$ ,Yo: &>As 分析 $Xf~# uH X )I/%{ 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ggMUdlU i"/ r)>"b
[attachment=67939] 图7. 字母F在视网膜上颜色分析
wtlB 脚本代码 Xe)Pg)J1 pH^ z Option Explicit 'Remove this to enable non-dimensioned variables to be used. {>S4#^@} #U\$@4D Dim entity As T_ENTITY 6tX.(/+L Dim op As T_OPERATION GX7VlI[ Dim mat As T_MODELMATERIAL 7Ez}k}aR< Dim A As Double HP#ki !' Dim pupilDiam As Double S
9WawI Dim eID As Long ;D:=XA% Dim parID As Long %@>YNPD`E Dim count As Integer T)`gm{T Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /\~l1.6` Dim tlens As Double, nlens As Double I I&< Dim curv As Double, conic As Double H%FM Dim ok As Long miPmpu! u]R$]&< Sub Main FZeP<Ban hX&-/fF+f '用户输入对话框 wtq,`'B Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ]XY0c6
< TextBox 220,21,40,21,.TextBox1 'default: 0 0"4J"q]& Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 >)4.$#H OKButton 40,91,90,21 K@HLIuz4t CancelButton 190,91,90,21 $khrWiX Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 li@kLh TextBox 220,49,40,21,.TextBox2 'default: 4 2f `&WUe End Dialog TWtC-wI; Dim dlg As UserDialog bZu$0IG jBS'g{y-! ok = Dialog (dlg) <H!O:Mf_p f:S}h-AL& If ok=0 Then 'cancel button was pressed 1PmX."a Print "Execution cancelled." ;>5, End lelMt= End If c+H)ed> (VEp~BW@-R 'Assign accommodation and pupil diameter & use defaults if field left empty 7O"hiDQ If dlg.TextBox1 = "" Then ZxI]I1) A = 0 'Default accommodation 2av*o~|J*: Else w\p9J0 A = CDbl(dlg.TextBox1) hw*1g m End If (N7O+3+G 5 1"8Py If dlg.TextBox2 = "" Then zqY)dk pupilDiam = 4 'Default pupil diameter Q]^Yi1PbS Else LGAX"/LX pupilDiam = CDbl(dlg.TextBox2) `wf|u M End If ]?M)NRk%S 9?$RO[vo Print " " ]b> pI; Print "Accommodation = " & A & " Diopters" {-J:4*` Print "Pupil Diameter = " & pupilDiam & " mm" 1EQvcw# Q4=|@|U0 ' Calculate new parameters with accommodation zx7#)* taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness RNvQ q1jN]H Rant = 12.0 - 0.4*A 'Radius of anterior lens v"/TmiZ CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens /e .D/;] V\"1wV~E Rpost = -5.224557 + 0.2*A 'Radius of posterior lens ",T`\8&@e CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens i2`# Vli3>K& tlens = 3.767 + 0.04*A 'Lens thickness 'Wtf>` jx'2N~$ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction m!0N"AjA K0v.3 'Adjust parameters to account for accommodation <$Z tik1 (2d3jQN` '************************************************************************* 1g~y]iQ 'Aqueous thickness (Position of Lens) z|Ap\[GS '************************************************************************* R2CQXhiJ eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 95[wM6?J GetCustomElement eID, entity W-ez[raY ljuNs@q parID = FindFullName( "Geometry.Arizona Eye" ) l^
Rm0t_ z,avQR& ' Delete any shift(s) in z Qww^P/vm count = 0 l0:5q?g While GetOperationCount(eID)>count x^X$M$o,l GetOperation eID, count, op &kiF/F 1 If op.Type="ShiftZ" Then aLYLd/ KV DeleteOperation eID,count ^EuW(
" count=count-1 )@_ugW-j End If gJK KR]4* count=count+1 \q,s?`+B Wend 4~Dax) -,|ha>r 'Set new shift in $
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L;j op.Type = "ShiftZ" HA1]M`& op.val1 = taq L{<7.?{Y op.parent = parID E23w *'] AddOperation eID, op q1w|'V Print "Set aqueous humor thickness = " & taq-0.55 ~$Y|ca ewym1}o '************************************************************************* 26 ?23J
; 'Radius and conic constant of anterior lens nEyIt&>9 '************************************************************************* ?&xlT+JM eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Je@k iE GetConic eID, entity, curv, conic kZv*rWAm rnH}#u+ SetConic eID, entity, 1/Rant, CCant _YLUS$Zw Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant r6MB"4xd {-h, ZdH^ '************************************************************************* 5 < GDW= 'Radius and conic constant of posterior lens Y&g&n o_ '************************************************************************* [%?y( q eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) \lW_f{X) GetConic eID, entity, curv, conic 'W(xgOP1 !UcOl0"6 SetConic eID, entity, 1/Rpost, CCpost Hd374U<8]T Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [;FofuZ cQn)^jx= '************************************************************************* ??(Kwtx{ 'Lens thickness (Position of posterior lens surface) p[-{]! '************************************************************************* jtCZfFD? `iQqhx parID = FindFullName( "Geometry.Arizona Eye.Lens" ) A9;0y jae u7#z^r ' Delete any z-shift(s) K$ AB} Fvc count = 0 puF%=i While GetOperationCount(eID)>count f?maa5S GetOperation eID, count, op c
D7FfJ If op.Type="ShiftZ" Then { *$9, DeleteOperation eID,count s:b"\7 count=count-1 C_Gzv'C"L End If W&KM/9d count=count+1 K}K)`bifw Wend vI|As+`$d I7zn>^0} 'Set new z-shift VMF|iB op.Type = "ShiftZ" Q;wB{vr$ op.val1 = tlens !+KhFC&Py op.parent = parID $H;+}VQ AddOperation eID, op )*D'csGc Print "Set lens thickness = " & tlens + Kk@Q H;y}-=J+ '************************************************************************* F~R7~ZE 'Lens index of refraction Gkmsaf> '************************************************************************* `)tA
YH eID = FindMaterial( "Lens" ) ]7vf#1i< GetModelMaterial eID, mat $:;%bjSI |7c`(. mat.Nd = nlens "-0;#&! SetModelMaterial eID, mat 2*Q3.2 Z Print "Set lens index of refraction = " & nlens u*2JUI* Q.ukY@L.' '************************************************************************* FUqt)YHi 'Pupil diameter ~-<:+9m '************************************************************************* d1bhJK eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) SH=:p^J sUciFAb 'Adjust pupil diameter (trimming volume inner hole) (}jL_E RUX8qT(Z SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" -_|]N/v\ y\z > /q ' Adjust pupil location to just in front of the lens R@n5AN( parID = FindFullName( "Geometry.Arizona Eye" ) lwJip IO eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ;"@ :}_t count = 0 I4~^TrznRa While GetOperationCount(eID)>count <T4(H[9B GetOperation eID, count, op c,$mWTC If op.Type="ShiftZ" Then e1uMR-Q DeleteOperation eID,count @ef$b?wg count=count-1 5#!ogKQ(i End If RJPcn)@l count=count+1 &^+3errO Wend i| 4_m op.Type = "ShiftZ" #_fY4vEO op.val1 = taq-0.01 a(|xw op.parent = parID )eq}MaW+j AddOperation eID, op k>>`fE\K 5~U:@Tp Print "Set pupil diameter = " & pupilDiam &CUC{t$VHX F.0d4:A+ 'Update AZ Eye subassembly Description N&x:K+Zm. eID = FindFullName( "Geometry.Arizona Eye" ) Pi){ h~B> GetEntity eID, entity -|[~sj-p entity.Description = "Accommodation = " & A & "D" ^IgS SetEntity eID, entity u~}%1 b0YNac.l Update /RqhykgZ Print "DONE!" x.\XUJ4x @/(@/*+" End Sub {MxnIg7' Bk@WW#b 如果屈光度是4,光瞳直径是4,则会输出如下数据: #TATqzA 045\i[l= Accommodation = 4 Diopters :l`i4kx Pupil Diameter = 4 mm
"l2bx Set aqueous humor thickness = 2.81 qguVaV4Y Set anterior lens radius = 10.4 and conic constant = -2.375869 {XHk6w
*- Set posterior lens radius = -4.424557 and conic constant = -3.081019 N8 M'0i? Set lens thickness = 3.927 I%i:)6Un-y Set lens index of refraction = 1.42672 G4m4k Set pupil diameter = 4 HEpM4xe$ DONE! k9&@(G[K3 Q"'V9m7
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(文章来源:讯技光电)
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