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2021-10-22 09:55 |
Arizona眼睛模型
简介 M;Vx[s,#, U?|s/U 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。 A;kAAM +}9%Duim 模型 NmtBn^t :syR4A WM 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。 lBh {8a|2W )SDGj;j+
Table 1. AZ眼睛模型的定义 [BV{=;iD 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. 9@vY(k k ,9+@\ 光源 0W=IuPDU i,RK0q?> 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。 89 (k<m ]Uxx_1$, $k!@e M/R
图1. 光源和提示信息使用 U_I'Nz!^t 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。 I|R9@ TD3R/NP 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。 EKoCm)}d 80+"
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图2. 字母F光源的设定方法光 s` S<BX7 iSFgFJG^
图3. 字母F在视网膜上位置点列图 C8G['aQ 视网膜的散射 t<: XY $\P!P. 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 rqa;MPl y5R6/*;N. 45-pJf8F
图4. 视网膜朗伯散射设定 TS1k'<c? 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 /D~
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图5. 视网膜重点采样规格设定 '-v~HwC+/T 脚本 ZGp8$Y>r D@j `'&G 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: IPT}JX' wL%>
图6. 用户对话框的创建与编辑 }QC:!e,yG
图7. 用户对话框编辑器 &_-~kU1K^ 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。 mY%PG 余下的脚本计算与屈光度有关的所有参数。 K, 35* I.(
9{ 分析 }S42.f.p Ajq<=y`NzV 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 #D}NT*w/ W~7q&||;C
图7. 字母F在视网膜上颜色分析 Z&}94 脚本代码 sjzZl*GSy hy6px Option Explicit 'Remove this to enable non-dimensioned variables to be used. -EL"Sv? u37+B Dim entity As T_ENTITY .UJDn^@ Dim op As T_OPERATION ~w!<J-z) Dim mat As T_MODELMATERIAL 2 K`
hH Dim A As Double n7Re@'N< Dim pupilDiam As Double -$mzzYH Dim eID As Long 7qnw.7p Dim parID As Long k-w._E
< Dim count As Integer \9 ^wM>U Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double M\T6cN@m Dim tlens As Double, nlens As Double Z/2#h<zj Dim curv As Double, conic As Double ?N`W, Dim ok As Long y|1-,u.$ Ejn19{ Sub Main 3:76x %7hYl'83 '用户输入对话框 O*c+TiTb Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 /dtFB5Z"w TextBox 220,21,40,21,.TextBox1 'default: 0 .+ _x|?' Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 :x16N|z OKButton 40,91,90,21 M(5l Su CancelButton 190,91,90,21 n.Ekpq\ Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 R|5w :+=z TextBox 220,49,40,21,.TextBox2 'default: 4 "|&SC0* End Dialog m}8c.OJ>K` Dim dlg As UserDialog HhIa=,VY C/lpSe ok = Dialog (dlg) ek3/`]V: J/
4kS<c If ok=0 Then 'cancel button was pressed XFH7jHnL+U Print "Execution cancelled." \GBv@ End q?JP\_o: End If *n}{)Ef 0~"{z>s ' 'Assign accommodation and pupil diameter & use defaults if field left empty 7eZ,;
x If dlg.TextBox1 = "" Then OCF=)#}qd A = 0 'Default accommodation hfVJg7- Else f`vB$r> A = CDbl(dlg.TextBox1) ,@(lYeD" End If (LQ*U3J]_ i?||R|>;"' If dlg.TextBox2 = "" Then 4fp}`U pupilDiam = 4 'Default pupil diameter l8jm7@.E Else &@nI(PXv pupilDiam = CDbl(dlg.TextBox2) W!htCwnkF End If Br;1kQ%e C ".~,(* Print " " $M#G;W5c Print "Accommodation = " & A & " Diopters" uBH4E;[f Print "Pupil Diameter = " & pupilDiam & " mm" @2Z{en? ?>DN7je ' Calculate new parameters with accommodation V+-%$-w> taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness j%Usui<DL x7> '
1 Rant = 12.0 - 0.4*A 'Radius of anterior lens
3hGYNlQ^ CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens PA&Ev0`+ M;-PrJdyt Rpost = -5.224557 + 0.2*A 'Radius of posterior lens Wi)Y9frE CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens 9J$N5 X8"4)IZ3 tlens = 3.767 + 0.04*A 'Lens thickness ]]V|[g&aJ ?sk{(UN] nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction /&_$+Iun xN'$Yh
'Adjust parameters to account for accommodation +9<"Y6 +d>?aqI\A '************************************************************************* e?,n> 'Aqueous thickness (Position of Lens) *%E4,(T '************************************************************************* kZ>_m&g eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #~BsI/m GetCustomElement eID, entity 9$$dSN\& h'jc4mu0 parID = FindFullName( "Geometry.Arizona Eye" ) )%dxfwd6 s'b 4Me ' Delete any shift(s) in z FC@h6\+a count = 0 tp*.'p-SI While GetOperationCount(eID)>count nl5A{ s GetOperation eID, count, op w;W# 'pE If op.Type="ShiftZ" Then -M5vh~Tp DeleteOperation eID,count d<K2
\:P{} count=count-1 \2)D
End If Swa0TiT( count=count+1 0Un?[O Wend ,cE yV74 `%; Hj _X} 'Set new shift in B>.x@(}V~ op.Type = "ShiftZ" 0v+-yEkw op.val1 = taq FJ,"a%m/Q op.parent = parID /9ctmW1!< AddOperation eID, op >m]LV}">O Print "Set aqueous humor thickness = " & taq-0.55 ,_iq$I; aKjP{Z0k$ '************************************************************************* Rjp7H 'Radius and conic constant of anterior lens M8nfbc^ '************************************************************************* ;NU-\<Q{ eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) @,Z0u2WLl6 GetConic eID, entity, curv, conic .DNPL5[v xt_:R~/[ SetConic eID, entity, 1/Rant, CCant V6Mt;e)C Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant y+3+iT@i % IHIXncv[ '************************************************************************* *4/FN TC 'Radius and conic constant of posterior lens >)F "lR:o '************************************************************************* `AYq,3V eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) /sfJ:KP0 GetConic eID, entity, curv, conic ?4A/?Z]ub hw$!LTB2 SetConic eID, entity, 1/Rpost, CCpost L!>nl4O>` Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost '2GnA ws^ F~q(@.b '************************************************************************* jp_|pC' 'Lens thickness (Position of posterior lens surface) Kci. ,I '************************************************************************* >H^#!eaqw ],_+J* parID = FindFullName( "Geometry.Arizona Eye.Lens" ) fuzB;Ea h5SJVa ' Delete any z-shift(s) l+[:Cni count = 0 ~wa6S? While GetOperationCount(eID)>count *,mI=1 GetOperation eID, count, op (`S^6-^ If op.Type="ShiftZ" Then k,[*h-{8 DeleteOperation eID,count DY -5(6X count=count-1 ^|H={pd'c0 End If h%:rJ_#Zl count=count+1 V(_1q Wend "$XX4w
M RWc<CQcL" 'Set new z-shift RFMPh<Ac op.Type = "ShiftZ" xNzGp5H op.val1 = tlens /TyGZ@S>m op.parent = parID <XIIT-b[ AddOperation eID, op <q8@a0e@ Print "Set lens thickness = " & tlens |RFBhB/u >~SS^I0 '************************************************************************* nq)F$@ 'Lens index of refraction ,;_+o] '************************************************************************* T1]?E]m{ eID = FindMaterial( "Lens" ) 1h&`mqY)L. GetModelMaterial eID, mat MF8-q'upyT HR}O:2' mat.Nd = nlens G
5;6q SetModelMaterial eID, mat ")T\_ME Print "Set lens index of refraction = " & nlens ]K"&Vd 1@DC#2hPr '************************************************************************* uMJ\ 'Pupil diameter 6RnzT d '************************************************************************* qOwql(vX eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Ix5&B6L8 9 3>4n\ 'Adjust pupil diameter (trimming volume inner hole) [ QiG0D_'= rZ~w_DK* SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" .\n` 4A1z l~6K}g? ' Adjust pupil location to just in front of the lens )th[fUC( parID = FindFullName( "Geometry.Arizona Eye" ) U[@y8yN6M eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) {_QdB;VwH count = 0 .UG`pRC While GetOperationCount(eID)>count jN\u}!\O GetOperation eID, count, op TmsIyDcD~ If op.Type="ShiftZ" Then zxbfh/= DeleteOperation eID,count Jsz!ro count=count-1 rO'DT{Yt End If ''y.4dvX count=count+1 mQj=-\p Wend K#0TD(" op.Type = "ShiftZ" CkT(\6B- op.val1 = taq-0.01 i[o 2(d, op.parent = parID 1~5DIU^ AddOperation eID, op Bq q=2lj ;mkkaW,D* Print "Set pupil diameter = " & pupilDiam
c0oHE8@ #Wk=y?sn 'Update AZ Eye subassembly Description Zt `Tg7m eID = FindFullName( "Geometry.Arizona Eye" ) hF%M!otcJ- GetEntity eID, entity o~Se[p entity.Description = "Accommodation = " & A & "D" E/P~HE{ SetEntity eID, entity Mo,&h?VOM? ZJYn[\] Update =V^-@ji)b Print "DONE!" Gv:~P_vBH[ CMa6':~ End Sub VdLoi\-/L CXa[%{[n 如果屈光度是4,光瞳直径是4,则会输出如下数据: JVZ-nHf(9 E}@C4pS Accommodation = 4 Diopters 6':iW~iI Pupil Diameter = 4 mm T] zEcx+e Set aqueous humor thickness = 2.81 3k Ci5C Set anterior lens radius = 10.4 and conic constant = -2.375869 d*gAL<M7E Set posterior lens radius = -4.424557 and conic constant = -3.081019 {& o^p! Set lens thickness = 3.927 |#oS7oV( Set lens index of refraction = 1.42672 d1b]+A G4 Set pupil diameter = 4 c{z$^)A/ DONE! H_+n_r*
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