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2020-12-09 09:18 |
Arizona眼睛模型
简介 di;~$rI!? pvWNiW:~k 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。 5> 81Vhc, 6ZjUC1 模型 Y xnZ0MY Nt
tu)wr 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。 {_>XsB {DVMs|5;^
Table 1. AZ眼睛模型的定义 _+}o/449 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. {#=o4~u%;H 'Q*.[aJt 光源 KsTE)@F: /`qQWB5b 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。 $U&p&pgH=W uv$utu><
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图1. 光源和提示信息使用 4<EC50@. 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。 zl, Vj%d MO1H?Uhx 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。 ]:#W$9,WL &G-dxET]
图2. 字母F光源的设定方法光 75h]#k9\ 'K23oQwDB
图3. 字母F在视网膜上位置点列图 [$]-W$j+ 视网膜的散射 uxX 3wY;M RdjoVCf 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 !(S.7#-r `/G9*tIR8g Eg4&D4TGp
图4. 视网膜朗伯散射设定 f DXTedrG/ 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 1vh[sKv9% /+<G@+( M?m@o1\;W
图5. 视网膜重点采样规格设定 1Fsa}UK 脚本 1yS:` i:&$I= 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: *I9O63 X=jD^"-
图6. 用户对话框的创建与编辑 OJFWmZ(X
图7. 用户对话框编辑器 r.]IGE| 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。 L 'e|D=y 余下的脚本计算与屈光度有关的所有参数。
PmE8O }?CKE<#% 分析 R2Q1Rk# WQ{^+C9g'1 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。
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图7. 字母F在视网膜上颜色分析 b.
:2x4 脚本代码 V>4v6)N Gfepm$*% Option Explicit 'Remove this to enable non-dimensioned variables to be used. IR8qFWDZ <`BDN Dim entity As T_ENTITY R,l*@3Q Dim op As T_OPERATION k]c$SzJ> / Dim mat As T_MODELMATERIAL ;|,*zD Dim A As Double z>*\nomOn= Dim pupilDiam As Double EQy~ ^7V B Dim eID As Long C)cuy7< Dim parID As Long cf\GC2+"^$ Dim count As Integer $b) k Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double F~GIfJU Dim tlens As Double, nlens As Double ;IT'6m`@W Dim curv As Double, conic As Double 5hDm[*83 Dim ok As Long Q^'xVS_. CSzu$Hnq Sub Main pWeD,!f m&--$sr '用户输入对话框 Vzh\1cF Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 cOdgBi TextBox 220,21,40,21,.TextBox1 'default: 0 9$ixjkIg Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 C jz(-018 OKButton 40,91,90,21 NC"X{$o2 CancelButton 190,91,90,21 Upc_"mkI. Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 $F@ ,,* TextBox 220,49,40,21,.TextBox2 'default: 4 p-6T,') End Dialog iG{xDj{CKv Dim dlg As UserDialog M?qvI LKM;T- ok = Dialog (dlg) I9sQPa T?*f}J If ok=0 Then 'cancel button was pressed Bf$`Hf6 Print "Execution cancelled." l(Uwci End .6pVt_f0/ End If U ?6.UtNf /!pJ" @ 'Assign accommodation and pupil diameter & use defaults if field left empty XrGP]k6.^ If dlg.TextBox1 = "" Then 4@9xq<<5 A = 0 'Default accommodation =<r1sqf
Else +o K*5 Y A = CDbl(dlg.TextBox1) {Ok]$0L End If "8\2w]" YN7JJJ/~T If dlg.TextBox2 = "" Then 4
udW6U pupilDiam = 4 'Default pupil diameter OyIIJ!( Else 1-sG`% pupilDiam = CDbl(dlg.TextBox2) Z)<lPg!YAR End If ,b t
j6hg ` c" Print " " a-NicjV# Print "Accommodation = " & A & " Diopters" Am"&ApK Print "Pupil Diameter = " & pupilDiam & " mm" ~L"?C #1p\\Av ' Calculate new parameters with accommodation q!YAA\'31 taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness 4i+H(d n 5a5)hmO RB Rant = 12.0 - 0.4*A 'Radius of anterior lens kTm}VTr
1 CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens
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Yg8yAt Rpost = -5.224557 + 0.2*A 'Radius of posterior lens Q6xA@"GJ CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens 1YtK+,mz &W*^&0AV tlens = 3.767 + 0.04*A 'Lens thickness b[ ~-b 8Y/1+- nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction YVPLHwh/5 ]$I}r=
Em 'Adjust parameters to account for accommodation -]Q\G H`rd bE '************************************************************************* W@D./Th 'Aqueous thickness (Position of Lens) s133N? '************************************************************************* l\ VrD2j8 eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #g<6ISuf GetCustomElement eID, entity &"^U=f@v 22 feYm| parID = FindFullName( "Geometry.Arizona Eye" ) [gj>ey8T U+&Eps&NI ' Delete any shift(s) in z [OR"9W& count = 0 0!M'z While GetOperationCount(eID)>count \t)`Cp6,[b GetOperation eID, count, op .sD=k3d If op.Type="ShiftZ" Then 5t-,5 DeleteOperation eID,count `yO'-(@"gY count=count-1 ]88qjKL End If >~_)2_j count=count+1 ~EU\\;1Rmq Wend -,2CMS#N e0hY 'Set new shift in 6w[EJ;=p_ op.Type = "ShiftZ" my#\(E+ op.val1 = taq me-uPm op.parent = parID fg4mP_ AddOperation eID, op d0;?GQYn: Print "Set aqueous humor thickness = " & taq-0.55 ^!gq_x M~~)tJYsu '************************************************************************* 'c# }^@G 'Radius and conic constant of anterior lens bAwKmk9C '************************************************************************* {(I":rt# eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) !;0K=~(Y^ GetConic eID, entity, curv, conic x_r*<?OZ D"%> SetConic eID, entity, 1/Rant, CCant [2E(3`-u Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant n#@ Qd!uzM mhB2l/ '************************************************************************* QWtDZ> 'Radius and conic constant of posterior lens ^b.#4i(v '************************************************************************* 2f620 eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 6@eF|GoP GetConic eID, entity, curv, conic na"!"C
s3 bkS"]q)> SetConic eID, entity, 1/Rpost, CCpost pTXF^:8 Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;#:AM; hCS} '************************************************************************* qG ? :Q 'Lens thickness (Position of posterior lens surface) B{*{9!(l9 '************************************************************************* *"OUwEl a !F.h+&^D; parID = FindFullName( "Geometry.Arizona Eye.Lens" ) xF@&wg 8KYI Hw ' Delete any z-shift(s) 1GK>&; count = 0 _54gqD2C,
While GetOperationCount(eID)>count Rc
&m4|cw7 GetOperation eID, count, op cnI5G! If op.Type="ShiftZ" Then ^39lUKL DeleteOperation eID,count Z&U:KrFH count=count-1 AV7#,+p%G End If @&Bh!_TWc count=count+1 !&9(D^ Wend ]!&$&t8. m uy^>2p 'Set new z-shift o]RZd--c< op.Type = "ShiftZ" .ESvMK~x op.val1 = tlens 7ej u%d op.parent = parID o+7)cI AddOperation eID, op Ikw@B)0} Print "Set lens thickness = " & tlens +`_0tM1 6 dV )pJd '************************************************************************* &T~X`{V]` 'Lens index of refraction 8-Y*b89 '************************************************************************* ^6 z"@+;* eID = FindMaterial( "Lens" ) ;o9ixmT<-o GetModelMaterial eID, mat X6r0+D5AvB fBj)HoHQW mat.Nd = nlens doOuc4 SetModelMaterial eID, mat 1P*hC< Print "Set lens index of refraction = " & nlens hlB\Xt IEMa/[n/ '************************************************************************* `Y5LAt: 'Pupil diameter W(R~K - '************************************************************************* 5a$EXV eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) G(TFv\`vH Dzf\m>H[ 'Adjust pupil diameter (trimming volume inner hole) Dws)
4hH ; Byt'S SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" t15{>>f4> 75zU,0"j ' Adjust pupil location to just in front of the lens t`+A;%=K] parID = FindFullName( "Geometry.Arizona Eye" ) ?'z/S5&j eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) J\Pb/9M/ count = 0 ws+ '*7 While GetOperationCount(eID)>count Q_|}~4_+ GetOperation eID, count, op &hI!mo If op.Type="ShiftZ" Then N=KtW?C DeleteOperation eID,count 9<.O=-1~ count=count-1 '<BLkr# @ End If ld@+p count=count+1 m^}|LB:5 Wend $Dj8 a\L op.Type = "ShiftZ" YWl#!"- op.val1 = taq-0.01 i[IFD]Xy!j op.parent = parID G?'^"ae"Z AddOperation eID, op 0Eb4wupo A}(]J!rc Print "Set pupil diameter = " & pupilDiam 6dR+qJa6i *k62Qz3 'Update AZ Eye subassembly Description dX cbS< eID = FindFullName( "Geometry.Arizona Eye" ) Y
b3ckktY GetEntity eID, entity 8%#8PLB2 entity.Description = "Accommodation = " & A & "D" @6>Q&GYqt SetEntity eID, entity qqf`z,u W_`]7RO8 Update <v|"eq} Print "DONE!" N7_eLhPt*8 Lc{arhN End Sub KD &nLm! J 7R(X 如果屈光度是4,光瞳直径是4,则会输出如下数据: /B@{w-N QIGU i,R Accommodation = 4 Diopters GHcx@||C? Pupil Diameter = 4 mm :}zyd;Rc Set aqueous humor thickness = 2.81 z_$c_J Set anterior lens radius = 10.4 and conic constant = -2.375869 hi1Ial\Y Set posterior lens radius = -4.424557 and conic constant = -3.081019 >0{}tRm-P& Set lens thickness = 3.927 EVX3uC}{ Set lens index of refraction = 1.42672 :S0! Set pupil diameter = 4 CvY+b^ ; DONE! g8##Be 1RYrUg"s" ][$I~nRf QQ:2987619807 ,*XB11P
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