-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2025-11-26
- 在线时间1892小时
-
-
访问TA的空间加好友用道具
|
简介 2(,
`9 g' xR$6t 人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 \Lz2"JI 2hjR'6h"Y 模型 GYx_9"J\5 (ei;Y~i 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 S<hj6A 2 us-s Table 1. AZ眼睛模型的定义 W.xlS
ZEB 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. QFI8|i@ <eObQ[mQ 光源 +&W%]KEh {|}tp<:2 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 iaqhP7! b9ON[qOMN Z=ayVsJ3 图1. 光源和提示信息使用 *3yeMxa 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 >bf29tr /\%K7\ 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 h\ (z!7t* {[~
!6&2(k 图2. 字母F光源的设定方法光 +TzF*Np "d a%@Zy 图3. 字母F在视网膜上位置点列图 [TZlvX(E 视网膜的散射 cT8`l!RD< _)J;PbK~ 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 58H [sM4> q;T3bxp+ dbkkx1{>Y 图4. 视网膜朗伯散射设定 |(gq:O 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 VrF(0,-Z`3 `"0#lZ`n dOm#NSJVd 图5. 视网膜重点采样规格设定 5Rv6+d 脚本 IT,TSs/Y |~mi6 lJ6 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: `<Z5/;a5W w ' E 图6. 用户对话框的创建与编辑 1cE3uA7 图7. 用户对话框编辑器 x1m J&D 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 ubV|s|J 余下的脚本计算与屈光度有关的所有参数。 m6BIQ(l G<kslTPyq 分析 ^h+<Q%'a' }5H3DavW 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 1 l'Wb2g>A u>Z0ug6x 图7. 字母F在视网膜上颜色分析 '`q&UPg] 脚本代码 (F$V m .:tAZZ Option Explicit 'Remove this to enable non-dimensioned variables to be used. =J0X{Ovn4z ^$):Xz Dim entity As T_ENTITY iH& Izv Dim op As T_OPERATION <|~8Ezd Dim mat As T_MODELMATERIAL 7|6uY Dim A As Double @O}%sjC1 Dim pupilDiam As Double y4aSf2 Dim eID As Long _ x&Y'X| Dim parID As Long nB ?$W4 Dim count As Integer N"2Ire Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double '>AOJaA Dim tlens As Double, nlens As Double t\nYUL-H Dim curv As Double, conic As Double .jRp.U Dim ok As Long /dpEL9K VLW<"7I 6\ Sub Main Z~^)B8 ffK A '用户输入对话框 c>~"Z-VtX Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 dxkq* TextBox 220,21,40,21,.TextBox1 'default: 0 ANEW^\ Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 A-\OB
Nh OKButton 40,91,90,21 B&&:A4 CancelButton 190,91,90,21 Hu|;cbK Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 DVxW2J TextBox 220,49,40,21,.TextBox2 'default: 4 K!6k< End Dialog /
%}Xiqlrd Dim dlg As UserDialog S[rz=[7{ !T/^zc;G ok = Dialog (dlg) K1 M s Al="ss&2 If ok=0 Then 'cancel button was pressed yTWP1 Print "Execution cancelled." PSz|I8
c End P.WEu<$ End If g+oSbC MXsSF|- 'Assign accommodation and pupil diameter & use defaults if field left empty Sw<@u+Z;% If dlg.TextBox1 = "" Then
8%]o6'd4 A = 0 'Default accommodation ;
F% 3b47 Else iJE
$3 A = CDbl(dlg.TextBox1) x5vvY End If A{mv[x-XN iE$qq~% If dlg.TextBox2 = "" Then -@{5
u d pupilDiam = 4 'Default pupil diameter \EF^Ag Else s86Ij>VLf pupilDiam = CDbl(dlg.TextBox2) t<5$85Y~ End If Jylav: Vo^
i7 Print " " [+EmV >Y Print "Accommodation = " & A & " Diopters" '{+5+ J Print "Pupil Diameter = " & pupilDiam & " mm" .$5QM& 4 {JoeIRyz ' Calculate new parameters with accommodation 7 sv
3=/` taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness $_NYu R7u &` Rant = 12.0 - 0.4*A 'Radius of anterior lens v<
qN-zG CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens e E:J
@&(0]kZ6 Rpost = -5.224557 + 0.2*A 'Radius of posterior lens $'FPsoH CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens Os--@5e T$[50~ tlens = 3.767 + 0.04*A 'Lens thickness 9?$Qk0jc I;xrw?=\L nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction 8."B W8{g<.
/ 'Adjust parameters to account for accommodation ?7>G\0G )Y.H*ca '************************************************************************* .}
al s 'Aqueous thickness (Position of Lens) wWjZXsOd '************************************************************************* J:g4ES-/ eID = FindFullName( "Geometry.Arizona Eye.Lens" ) r'!L}^n GetCustomElement eID, entity o9I=zAGjy ~n9x
, parID = FindFullName( "Geometry.Arizona Eye" ) a=n*}. ,*_=w^;Rr ' Delete any shift(s) in z SB"Uu2)wZ count = 0 -JgN$Sf While GetOperationCount(eID)>count <y4hK3wP GetOperation eID, count, op 4mYJ i#e6x If op.Type="ShiftZ" Then -\=s+n_ZP? DeleteOperation eID,count cQM_kV??! count=count-1 WbF[4x End If /G*]3=cSe count=count+1 Eod'Esye5 Wend B?A]0S miWog 8j 'Set new shift in 5dwC~vn}c op.Type = "ShiftZ" 'x/pV5[hQ op.val1 = taq ->"Z1 op.parent = parID ~4-:;8a AddOperation eID, op t5t!-w\M$+ Print "Set aqueous humor thickness = " & taq-0.55 u*n%cXY;J/ );*:UzsC_ '************************************************************************* {\:"OcP # 'Radius and conic constant of anterior lens 1nGpW$Gx '************************************************************************* E}-Y!,v^ eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) D1G9^7:^E GetConic eID, entity, curv, conic (rTn6[* 3`
,u^ w SetConic eID, entity, 1/Rant, CCant 4^*+G]]wZ~ Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 6l Suzu 7LotN6H
'************************************************************************* C?OqS+ 'Radius and conic constant of posterior lens V.\12P '************************************************************************* _z6_mmMp eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) P]h-**O GetConic eID, entity, curv, conic 8&q[jxI@8 PCqE9B)l SetConic eID, entity, 1/Rpost, CCpost RX])#=Cs Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 7&O0 P:8qmDXo '************************************************************************* pDYcsC{p 'Lens thickness (Position of posterior lens surface) /&>vhpZ} '************************************************************************* -K%hug
A!GQ4.~% parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Sm5T/&z *'l|ws ' Delete any z-shift(s) d
U}kimz count = 0 Pl/}`H:R& While GetOperationCount(eID)>count b=$(`y GetOperation eID, count, op ja2BK\"1: If op.Type="ShiftZ" Then Ea<kc[Q DeleteOperation eID,count (JX 9c count=count-1 MP6Py@J45 End If ?"@`SEdnU2 count=count+1 YP4lizs. Wend %96l(JlJ)B 9YQYg@+R 'Set new z-shift tX.fbL@T op.Type = "ShiftZ" BbCaIt op.val1 = tlens H$M{thW op.parent = parID 4Pv Pp{Y AddOperation eID, op d_] sV4[ Print "Set lens thickness = " & tlens SoJ=[5W KAI/*G\z '************************************************************************* \2#j1/d4 'Lens index of refraction YQ$Wif:@(n '************************************************************************* p|0ZP6!| eID = FindMaterial( "Lens" ) 8M6wc394 GetModelMaterial eID, mat Sv>bU4LHf )RCva3Ul mat.Nd = nlens @3v[L<S{ SetModelMaterial eID, mat XF Cwa Print "Set lens index of refraction = " & nlens {b,#l]v }trQ<*D '************************************************************************* crlCN 'Pupil diameter /D~MHO{ '************************************************************************* W*WSjuFr2 eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 8#h~J>u. BenUyv1d 'Adjust pupil diameter (trimming volume inner hole) 8{B]_:
-: W6&mXJ^3L SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" g;-6Hg' qA>C<NL ' Adjust pupil location to just in front of the lens @.8FVF parID = FindFullName( "Geometry.Arizona Eye" ) c[zGWF#1> eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) o?`^
UG- count = 0 Aa!#=V1d While GetOperationCount(eID)>count L43]0k GetOperation eID, count, op M
$\!SXL If op.Type="ShiftZ" Then 1zGhX]z DeleteOperation eID,count []<N@a6VA> count=count-1 j`l'Mg End If "?Yf3G: \0 count=count+1 /I~(*X Wend XtftG7r9S op.Type = "ShiftZ" La8 D%N op.val1 = taq-0.01 G_v^IM#B= op.parent = parID \F8:6- AddOperation eID, op |y DaFv $Ma*q EB Print "Set pupil diameter = " & pupilDiam '9tV-whw i-M<_62c 'Update AZ Eye subassembly Description a_(fqoW eID = FindFullName( "Geometry.Arizona Eye" ) /;;$9O9 GetEntity eID, entity EY}*}- 3 entity.Description = "Accommodation = " & A & "D" f5P@PG]{ SetEntity eID, entity ?F^O7\rw 'q7&MM'oS^ Update
tk66Ggi[K Print "DONE!" Q=?YY-*$ Gq =i-I End Sub ftRzgW); |wkUnn4UB8 如果屈光度是4,光瞳直径是4,则会输出如下数据: Q7pjF`wu vC%Hc/&.} Accommodation = 4 Diopters 9/dI 6 P7 Pupil Diameter = 4 mm XLj|y#h Set aqueous humor thickness = 2.81 PwS7!dzH- Set anterior lens radius = 10.4 and conic constant = -2.375869 qt=nN-AC( Set posterior lens radius = -4.424557 and conic constant = -3.081019 2|JtRE+ Set lens thickness = 3.927 @,;VMO Set lens index of refraction = 1.42672 I.{%e;Reg Set pupil diameter = 4 rtT*2k* DONE! m/p:W/0L :$^cY>o KOit7+Q QQ:2987619807 @WTzFjv@?4
|