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2021-10-22 09:55 |
Arizona眼睛模型
简介 P0PWJ^+,+ 6,9>g0y'NG 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。 9lH?-~9 e?ly H 模型 >:!X.TG$ pKrN:ExB"\ 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。 \3aoM{ztD `&sH-d4v
Table 1. AZ眼睛模型的定义 V0XvJ
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. \:ak '' *zL}&RUKM 光源 qF-@V25P X;c'[q 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。 sCb=5uI '>ssqBnI 25[I=ZdS
图1. 光源和提示信息使用 1sdLDw_)p 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。 b4ONh% H_X [t* 2 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。 "#oHYz3D CxG#"{&
图2. 字母F光源的设定方法光 2M'[,Xe +sUFv)!4
图3. 字母F在视网膜上位置点列图 hPePB= 视网膜的散射 \\dMy9M- o-OHjFfB 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。 wN-d'-z/rd |NC*7/} mFaZio0GK
图4. 视网膜朗伯散射设定 ^R
Fp8w( 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。 5BKt1%Pg O7<]U_"I LS*y
图5. 视网膜重点采样规格设定 wlk4*4dKn 脚本 b@f$nS
B [^e%@TV>d 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: kep/+J-u dCk3;XU
图6. 用户对话框的创建与编辑 j4`0hnqI
图7. 用户对话框编辑器 lP@Ki5 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 ?!cvf{a 余下的脚本计算与屈光度有关的所有参数。 Ksj -zR; LNpup`>` 分析 8'nVwb8I SY^t} A7:/ 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 kZZh"#W: L E5xzy/ZQ
图7. 字母F在视网膜上颜色分析 4^~(Mh- Mw 脚本代码 p@5`&Em, SB|Qa}62 Option Explicit 'Remove this to enable non-dimensioned variables to be used. /1Q(b 2Mmz %S'd Dim entity As T_ENTITY (Dl$k Gn Dim op As T_OPERATION u\{ g(li-I Dim mat As T_MODELMATERIAL s<_)$} Dim A As Double tEK my7'# Dim pupilDiam As Double U\;6mK)M^J Dim eID As Long RBm ;e0 Dim parID As Long JB`\G=PiL Dim count As Integer bMMh|F Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double C/kW0V7 Dim tlens As Double, nlens As Double v` 7RCg` Dim curv As Double, conic As Double [uq$5u Dim ok As Long s4SG[w!d R0vI bFwj Sub Main zN@}
#Hk >JCM.I0_| '用户输入对话框 O#k6' LN? Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 .5,(_p^ TextBox 220,21,40,21,.TextBox1 'default: 0 Vle@4]M\ Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 $!(pF OKButton 40,91,90,21 J}+6UlD CancelButton 190,91,90,21 DRgTe&+ Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 *
%M3PTY\ TextBox 220,49,40,21,.TextBox2 'default: 4 i2(1ki/|O End Dialog ;YX4:OBqr Dim dlg As UserDialog ); dT_ i Ae<&Ms ok = Dialog (dlg) {v2|g ?zVL;gVWA If ok=0 Then 'cancel button was pressed mvZw Print "Execution cancelled." 1ilBz9x*! End o=?C&f{ End If ur@Z|5 ;b(p=\i 'Assign accommodation and pupil diameter & use defaults if field left empty oifv+oY If dlg.TextBox1 = "" Then okv 1K A = 0 'Default accommodation :8+Ni d) Else aKuSd3E@# A = CDbl(dlg.TextBox1) c 8>hcV End If tAte)/0C *nsAgGKKM^ If dlg.TextBox2 = "" Then }S$@ Ez6 pupilDiam = 4 'Default pupil diameter .dQQoyR+O Else Zx bq pupilDiam = CDbl(dlg.TextBox2) WRDjh7~Efn End If me ks
RcF -'BA{#e}L Print " "
S"$m] Print "Accommodation = " & A & " Diopters" u[/m|z Print "Pupil Diameter = " & pupilDiam & " mm" HnCzbt@ I=9!Rs(QF ' Calculate new parameters with accommodation g[7#w,o taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness P(73!DT+ 8o0%@5M Rant = 12.0 - 0.4*A 'Radius of anterior lens ?Ovqp-sw CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens S'B|>!z@ q)vplV1A Rpost = -5.224557 + 0.2*A 'Radius of posterior lens H4!+q:< CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens OP|8S k6
r ~Oq +IA~9 tlens = 3.767 + 0.04*A 'Lens thickness
n>`as |{ PI102 nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction QtqfG{ y>|{YWbp? 'Adjust parameters to account for accommodation mzc
4/<th [.*;6y3 '************************************************************************* aKJQm'9Ks 'Aqueous thickness (Position of Lens) 1`9xIm*9w '************************************************************************* k`p74MWu eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #\ n8M GetCustomElement eID, entity e$uiJNS2 0,Y5KE{ parID = FindFullName( "Geometry.Arizona Eye" ) JA_BKA SdwS= (e6 ' Delete any shift(s) in z VA%Un,5h count = 0 ]$\|ktY! While GetOperationCount(eID)>count n[,w f9 GetOperation eID, count, op R
&4Z*?S If op.Type="ShiftZ" Then *(>}Y DeleteOperation eID,count { F}; n?' count=count-1 t
6^l `6:p End If C2w2252T count=count+1 &0 BdUU+:< Wend .eO?Z^ wL^%w9q- 'Set new shift in pdEiqLhH op.Type = "ShiftZ" $4T2z- op.val1 = taq {E0z@D)U- op.parent = parID 0W()lQ AddOperation eID, op 3#45m+D Print "Set aqueous humor thickness = " & taq-0.55 F5qFYL; z>06hBv(?Y '************************************************************************* N#_GJSG_| 'Radius and conic constant of anterior lens 5rV(( '************************************************************************* k') E/n eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) = }:)y0L GetConic eID, entity, curv, conic FsGlJ $VQtwuYt SetConic eID, entity, 1/Rant, CCant y{a$y}7#X Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant *cg(
?yg ?[MsQQd~ '************************************************************************* `3'0I /d"z 'Radius and conic constant of posterior lens Iu35#j '************************************************************************* Ep4Hqx $ eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) C}*cx$. GetConic eID, entity, curv, conic oo$MWN8a>r [J0v&{)? SetConic eID, entity, 1/Rpost, CCpost ' 2-oh Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost &X]\)`j0 leiW4Fj '************************************************************************* %&\ jOq~ 'Lens thickness (Position of posterior lens surface) =0'q!}._! '************************************************************************* 5Fm=/o1 sfVf@0g parID = FindFullName( "Geometry.Arizona Eye.Lens" ) eb8w~
l"zUv ' Delete any z-shift(s) 8g>b count = 0 0J8K9rP;z While GetOperationCount(eID)>count {3Vk p5%l GetOperation eID, count, op *AIEl"29 If op.Type="ShiftZ" Then =)OC|?9C\ DeleteOperation eID,count Fequm+ count=count-1 ^-M^gYBR End If \ M/6m^zS count=count+1 ,s^<X85gp\ Wend "XLe3n sF+=KH 'Set new z-shift ksjUr 1o op.Type = "ShiftZ" 1Ee>S\9t op.val1 = tlens te4= S
op.parent = parID '~wpP=<yyF AddOperation eID, op -NBiW6b~ Print "Set lens thickness = " & tlens Us~ X9n_F ^aRgMuU '************************************************************************* 7CB#YP?E 'Lens index of refraction kDz>r#% '************************************************************************* ]^\8U2q} eID = FindMaterial( "Lens" ) Q:|w%L*E
GetModelMaterial eID, mat K$REZe s-VSH mat.Nd = nlens !1uzX
Kb SetModelMaterial eID, mat (a6?s{( Print "Set lens index of refraction = " & nlens b]]N{: I NgB 7?]vu '************************************************************************* ^`qPs/b 'Pupil diameter .]}N55M '************************************************************************* T_OF7? eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) [ev-^[ XvSIWs 'Adjust pupil diameter (trimming volume inner hole) Z]:BYX' a1MFjmq SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" []&(D_e" =<<3Pkv7@ ' Adjust pupil location to just in front of the lens 8Xm@r#Oy5 parID = FindFullName( "Geometry.Arizona Eye" ) ev>oC~>s eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ZcryAm:I count = 0 (=T$_-Dj`} While GetOperationCount(eID)>count | D.C!/69 GetOperation eID, count, op n!N\zx8 If op.Type="ShiftZ" Then Dr"/3xm DeleteOperation eID,count 04y!\ count=count-1 o+g4p:Mf End If w&lZ42(mF count=count+1 xKJ>gr"w# Wend a`Z{
xme= op.Type = "ShiftZ" CJqc\I~ op.val1 = taq-0.01 :LV.G0)# op.parent = parID ^@}#me@ AddOperation eID, op pX<a2FP nJVp.*S Print "Set pupil diameter = " & pupilDiam *PM}"s R.7#zhC`4 'Update AZ Eye subassembly Description TV{)n'aA eID = FindFullName( "Geometry.Arizona Eye" ) cj(X2L GetEntity eID, entity =wA5P@ entity.Description = "Accommodation = " & A & "D" ?TuI:dC SetEntity eID, entity ^&:'NR M g!ra" Update %N~;{!![p Print "DONE!" 2;N@aZX !.+"4TF End Sub 7>x;B u3wL<$2[8 如果屈光度是4,光瞳直径是4,则会输出如下数据: 6D9o08 ~Ob8i 1S> Accommodation = 4 Diopters +?e}<#vd'? Pupil Diameter = 4 mm YhgUCF# Set aqueous humor thickness = 2.81 v"k4ATWP Set anterior lens radius = 10.4 and conic constant = -2.375869 9oq)X[ Set posterior lens radius = -4.424557 and conic constant = -3.081019 s -Y +x Set lens thickness = 3.927 <"I?jgo Set lens index of refraction = 1.42672 RWahsJTu Set pupil diameter = 4 ${e&A^h DONE! R|t;p!T
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