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2016-02-24 12:53 |
FRED运用:Arizona眼睛模型
简介 QH7 GEj] 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。 47{5{/B- sieC7raO 模型 {gu3KV }z9v*C 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。 hRB?NM ?A .ah
Table 1. AZ眼睛模型的定义 [attachment=67931] csJ)Pt?d 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. jbT{K|d- yEh{9S%6p 光源 Gi@c`lRd1 x2HISxg 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。 }{,Wha5\n tfm3IX 6'uCwAQU
[attachment=67932] 图1. 光源和提示信息使用 :p)^+AF"5 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。 3PLA*n+% T?Z^2.Pvc 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。 PX23M|$! Q3bU"f
[attachment=67933] 图2. 字母F光源的设定方法光 Lq.2vfA> |)&d9|]
[attachment=67934] 图3. 字母F在视网膜上位置点列图 N|"kuRN# 视网膜的散射 @6R6.i5d suWO:]FR 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 hz<TjWXv' j5/|1N %FqQ+0^
[attachment=67935] 图4. 视网膜朗伯散射设定 \WdSj 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 h|Qb:zEP, Ii/{xVMD <rui\/4NJ
[attachment=67936] 图5. 视网膜重点采样规格设定 cZoj|=3a 脚本 >XiT[Ru Z1$U[Tsd 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: jRDvVV/-wr [,ulz4"
[attachment=67937] 图6. 用户对话框的创建与编辑 d,
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[attachment=67938] 图7. 用户对话框编辑器 ij3W8i9' 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]K$yo 余下的脚本计算与屈光度有关的所有参数。 *6=9 8C4I =^{MyR7 分析 :.a184ax B *6ncj 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 SGy2&{\Z `*kl> }$
[attachment=67939] 图7. 字母F在视网膜上颜色分析 fsnZHL}=n 脚本代码 SG0PQ SH8zkAA7u} Option Explicit 'Remove this to enable non-dimensioned variables to be used. v7#|% a{JO8<dlm Dim entity As T_ENTITY cuy9QBB
: Dim op As T_OPERATION tW-[.Y -M, Dim mat As T_MODELMATERIAL Tj<B;f!u Dim A As Double "VoufXM: Dim pupilDiam As Double *0V'rH) Dim eID As Long yFd942 Dim parID As Long &U}8@; Dim count As Integer iG~&uEAJ Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #QSSpsF@ Dim tlens As Double, nlens As Double bt.3#aj Dim curv As Double, conic As Double Hmx.BBz Dim ok As Long kG}F/GN? Vwjic2lGI Sub Main OpIeo+^X* jk\V2x@DR '用户输入对话框 VTyj<6Y Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 E
GZiWBr TextBox 220,21,40,21,.TextBox1 'default: 0 i`vy<Dvpz Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 w5/6+@} OKButton 40,91,90,21 >@4AxV\ CancelButton 190,91,90,21 }?+tX <j Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 L?&&4%% TextBox 220,49,40,21,.TextBox2 'default: 4 S}]B |Q End Dialog ?q2Yk/P Dim dlg As UserDialog +$2`"%nBG Zv-1*hhHf ok = Dialog (dlg) mDD96y T:|p[Xbo If ok=0 Then 'cancel button was pressed ryA+Lli. Print "Execution cancelled." %,ScGQE End +bJ~S:[ End If _RZ"WA^[ |m@>AbR5dk 'Assign accommodation and pupil diameter & use defaults if field left empty %Lh+W<; If dlg.TextBox1 = "" Then :7dc;WdM A = 0 'Default accommodation ,]]IJ;:w Else QF*cdc< A = CDbl(dlg.TextBox1) )"6"g9A End If Wyeb1 YmjA!n If dlg.TextBox2 = "" Then 5tZ0zr pupilDiam = 4 'Default pupil diameter ssoE ,6kS Else y"U)&1 c% pupilDiam = CDbl(dlg.TextBox2) ZBN,%P!P0 End If sdyNJh7Jr v*<rNZI Print " " `s Pk:cNz~ Print "Accommodation = " & A & " Diopters" 87eH~&<1 Print "Pupil Diameter = " & pupilDiam & " mm" k"/Rjd(; , `EOJ"| ' Calculate new parameters with accommodation K~S*<? taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness Sl<1Rme=w Zkqq< Rant = 12.0 - 0.4*A 'Radius of anterior lens h.l.da1# CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens w1VYU> .c__T{<)[ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens b0@K ~O;g CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens uZ>q$
F gMkSl8[ tlens = 3.767 + 0.04*A 'Lens thickness Km,o+9?1gF u7Ix7`V nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction `Lavjmfr2V
_Rkvg- 'Adjust parameters to account for accommodation 8pftc) k u%I%4 gM '************************************************************************* n4}e!
'Aqueous thickness (Position of Lens) a)Pr&9I '************************************************************************* "zCT S eID = FindFullName( "Geometry.Arizona Eye.Lens" ) P4eH:0=# GetCustomElement eID, entity W|uRQA` O|^J;fS: parID = FindFullName( "Geometry.Arizona Eye" ) c14d0x{ Oe
:S1 f ' Delete any shift(s) in z |_-w{2K count = 0 F[!%,-* While GetOperationCount(eID)>count tns8B GetOperation eID, count, op k_zn>aR$F If op.Type="ShiftZ" Then `YE=B{q DeleteOperation eID,count ;FF+uK count=count-1 $ Y^0l End If [C<K~ count=count+1 ,R3TFVV!? Wend 3
v.8 / #rH18 'Set new shift in M+HhTW;I= op.Type = "ShiftZ" ,9_O4O% op.val1 = taq kS9;Tj cx op.parent = parID 3/yt AddOperation eID, op b09xf"D Print "Set aqueous humor thickness = " & taq-0.55 4#]g852 ZZTf/s* '************************************************************************* llWY7u" 'Radius and conic constant of anterior lens g7*Uuh# '************************************************************************* -38"S;M8 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;Oqf{em]; GetConic eID, entity, curv, conic 'd&d"E[ G +41D SetConic eID, entity, 1/Rant, CCant .s!0S-RkC Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant V@b7$z 4\ *:Lc,- '************************************************************************* Ldv,(ZV,< 'Radius and conic constant of posterior lens =s]2?m '************************************************************************* ^H1m8= eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Nq8 3 6HL GetConic eID, entity, curv, conic XBkaum4j KF1iYo>p SetConic eID, entity, 1/Rpost, CCpost kD%MFT4 Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost eB1NM<V !k*B-@F '************************************************************************* |uw48*t 'Lens thickness (Position of posterior lens surface) F --b,, '************************************************************************* 5p S$rf vc p{Gf|^ parID = FindFullName( "Geometry.Arizona Eye.Lens" ) @fp@1n z5(5\j] ' Delete any z-shift(s) oq!\100 count = 0 ]BjYUTNm While GetOperationCount(eID)>count b$fmU"%&| GetOperation eID, count, op YlGUd~$`"+ If op.Type="ShiftZ" Then L8f+uI DeleteOperation eID,count 0Ui_Trlc count=count-1 Us'JMZ~ End If <PuY"-`/Oc count=count+1 &y=OZ
!M Wend etiUt~W gT$WG$^i 'Set new z-shift lnyq%T[^ op.Type = "ShiftZ" d v[.u{#tP op.val1 = tlens *GBV[D[G, op.parent = parID O TlqJ AddOperation eID, op :f39)g5> Print "Set lens thickness = " & tlens ~/-SKGzo- r0lI&25w '************************************************************************* SM
RKEPwp& 'Lens index of refraction LTo!DUi` '************************************************************************* eaDZ^Z
Er eID = FindMaterial( "Lens" ) %H" GetModelMaterial eID, mat YtSYe% /*Q3=Dse] mat.Nd = nlens wzwv>@} SetModelMaterial eID, mat Q5Nbu90 Print "Set lens index of refraction = " & nlens <ml?DXT 0[%{YmI{W '************************************************************************* V61oK 'Pupil diameter ;7?oJH; '************************************************************************* Is3Y>oX eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6wwbH}*=? #xu1
eX0< 'Adjust pupil diameter (trimming volume inner hole) *K$a;2WjzG ^[HUtq SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" x,10o ]J!#"m-] ' Adjust pupil location to just in front of the lens yGt[Qvx# parID = FindFullName( "Geometry.Arizona Eye" ) +[uh);vD`G eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) zc;kNkV#1Y count = 0 *v K~t|z While GetOperationCount(eID)>count lV^:2I/ GetOperation eID, count, op 8\'tfHL If op.Type="ShiftZ" Then vvxD}p=y DeleteOperation eID,count *kK +Nvt8s count=count-1 w/(T End If L3wj vq^ count=count+1 8gE p5 Wend R0*P,~L;| op.Type = "ShiftZ" C za}cF op.val1 = taq-0.01 XBCHJj]k op.parent = parID e\[q3J AddOperation eID, op [j@i^B & OQ_<V xz Print "Set pupil diameter = " & pupilDiam tyW[i8)O} GiuE\J9i 'Update AZ Eye subassembly Description 'h6G"=+ eID = FindFullName( "Geometry.Arizona Eye" ) UF5_be,D GetEntity eID, entity TK'
5NM+4 entity.Description = "Accommodation = " & A & "D" sgK =eBE SetEntity eID, entity FO_}9 <s y4p"LD5%^ Update c)^A|{,G Print "DONE!" 0Q7<;'m G5t7KI End Sub 8w[O% ETL7|C" 如果屈光度是4,光瞳直径是4,则会输出如下数据: L{>rN`{ ;k#_/c Accommodation = 4 Diopters PZV>A!7C8n Pupil Diameter = 4 mm j1{`}\e Set aqueous humor thickness = 2.81 ti9e(Jt!O Set anterior lens radius = 10.4 and conic constant = -2.375869 'G % ]/'_U Set posterior lens radius = -4.424557 and conic constant = -3.081019 iN'T^+um= Set lens thickness = 3.927 C/N;4 Set lens index of refraction = 1.42672 5TuwXz1v Set pupil diameter = 4 MYara;k DONE! y,&[OrCm^\ &glh >9:G
(文章来源:讯技光电)
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