-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2025-04-02
- 在线时间1761小时
-
-
访问TA的空间加好友用道具
|
简介 0y3<Ho,+$ +L$,jZqS 人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 QFfKEMN M5Twulz/w 模型 f @cs<x DB>Y#2j4h 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 dTV:/QM iC{~~W6 Table 1. AZ眼睛模型的定义 P"g
Y|}| 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. +H K)A%QI hR$lX8 光源 dLSnhZ cc%O35o 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。 Y)@PGxjz _0rHxh7}q $pT%7jV} 图1. 光源和提示信息使用 QxGQF| 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。 '1}rQq Z YORFq9a{R 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。 1x0 7ua@(v !7g
E 图2. 字母F光源的设定方法光 1@ j>2>i x Qh? 图3. 字母F在视网膜上位置点列图 =oF6|\]{; 视网膜的散射 I@=h|GM mF>CH]k3 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。 !j(KbAhWZ )r2$/QF9 ~EU[? 图4. 视网膜朗伯散射设定 ~PNO|]8j 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 oPNYCE DJE/u qE NEO~|B*oDU 图5. 视网膜重点采样规格设定 'D-#,X
C 脚本 K]bS:[34 R LoG@(g&) 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: zJMKgw,i* s\&_Kbw]c 图6. 用户对话框的创建与编辑 Yf:utCvv 图7. 用户对话框编辑器 (nrrzOax 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 9ok|]d P 余下的脚本计算与屈光度有关的所有参数。 HHZ!mYr *eXO?6f%s^ 分析 K74oRKv ^+[o+ 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 dW7dMx U!a"r8u|8q 图7. 字母F在视网膜上颜色分析 G
7)D+],{Y 脚本代码 6\,^MI J'O`3!Oy/ Option Explicit 'Remove this to enable non-dimensioned variables to be used. 0iXqAa MatC2-aV1 Dim entity As T_ENTITY p 8"(z@T Dim op As T_OPERATION 8{+~3@T Dim mat As T_MODELMATERIAL fnnwe2aso Dim A As Double 1|w,Z+/ Dim pupilDiam As Double 73~Mq7~8 Dim eID As Long :,q3?l6 Dim parID As Long nu0bJ:0aLd Dim count As Integer 6sy%KO*A Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double [/uKo13 Dim tlens As Double, nlens As Double b+p!{ Dim curv As Double, conic As Double 8
(^2 Dim ok As Long ;D8Nya>% \N#)e1.0P Sub Main e+R.0E 5,AQ~_,'\ '用户输入对话框 <Awx:lw. Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 jX&&@zMq TextBox 220,21,40,21,.TextBox1 'default: 0 Y0B*.H
Ae Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g&0GO:F` OKButton 40,91,90,21 8)POEY4 CancelButton 190,91,90,21 N~>?w#?J Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9jPb-I- TextBox 220,49,40,21,.TextBox2 'default: 4 b$R>GQ?# End Dialog deTbvl Dim dlg As UserDialog 9_>4~!x` 4}LF>_+= ok = Dialog (dlg) wCt+{Y3T qfYb\b If ok=0 Then 'cancel button was pressed y]jh*KD[ Print "Execution cancelled." Ee|+uQ981> End aY:(0en]& End If Gm2rjpZeq e4)gF* 'Assign accommodation and pupil diameter & use defaults if field left empty 'c$9[|x If dlg.TextBox1 = "" Then rFy9K4D A = 0 'Default accommodation <dYk|5AdLF Else Fcr@Un' A = CDbl(dlg.TextBox1) c&Zm>Qo[
End If =-VV` Z],"<[E If dlg.TextBox2 = "" Then FoG<$9 pupilDiam = 4 'Default pupil diameter `X^e}EGWu Else \34|9#*z- pupilDiam = CDbl(dlg.TextBox2) )(L&+DDy End If Mc}x]j`f #wjBMR% Print " " M<p )@p Print "Accommodation = " & A & " Diopters" Y+j KP*ri Print "Pupil Diameter = " & pupilDiam & " mm" kTk?[BK |fI%L9 ' Calculate new parameters with accommodation Ksp;bfe taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness iE Oyc59 nDOIE)# Rant = 12.0 - 0.4*A 'Radius of anterior lens Y@4vQm+ CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens >@L
HJ61C Ur-^X(nL Rpost = -5.224557 + 0.2*A 'Radius of posterior lens V0AX1?H~ w CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens XGoy#h {;}8Z $ tlens = 3.767 + 0.04*A 'Lens thickness $($SQZK& ~+np7 nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction \S<5b&G
aOD"z7}U 'Adjust parameters to account for accommodation y%,BDyK P8VU&b\ '************************************************************************* Qm.kXlsDI 'Aqueous thickness (Position of Lens) 1}uDgz^ '************************************************************************* %pp+V1FH eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (
7?%Hg GetCustomElement eID, entity op-#Ig$# o/zCXZnw# parID = FindFullName( "Geometry.Arizona Eye" ) 0hkuBQb\ ,![=_ d ' Delete any shift(s) in z ;9PM?Iy[ count = 0 UH.cn|R While GetOperationCount(eID)>count O$H150,Q GetOperation eID, count, op dvD<>{U,8 If op.Type="ShiftZ" Then SHk[X ]Uo DeleteOperation eID,count (6BCFl:/Q< count=count-1 +o End If |u{QI3#' count=count+1 mb/[2y < Wend ! -c*lb eC$v0Gtq 'Set new shift in {Pb^Lf > op.Type = "ShiftZ" K|G$s op.val1 = taq C'._}\nX op.parent = parID i-?zwVmn AddOperation eID, op lz (,;I'x Print "Set aqueous humor thickness = " & taq-0.55 jEsTw_ ]CZLaID~
'************************************************************************* V</T$V$ 'Radius and conic constant of anterior lens 0'hx w3# '************************************************************************* T]|O/ eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) I{zE73 GetConic eID, entity, curv, conic i'wF>EBz sPg6eAd~? SetConic eID, entity, 1/Rant, CCant C.E>) Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant kMl< wP/9z(US '************************************************************************* u mlZ(??. 'Radius and conic constant of posterior lens 9@Sb! 9h '************************************************************************* 3~</lAm; eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) V@:=}*E GetConic eID, entity, curv, conic 9yo[T(8 <88}+j SetConic eID, entity, 1/Rpost, CCpost P$/A! r Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost yl<$yd0Zdu W<91m* '************************************************************************* (eG]Cp@ 'Lens thickness (Position of posterior lens surface) |/^aLj^u '************************************************************************* `U_>{p&x s66XdM parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?gwbg* ~e<'t4 ' Delete any z-shift(s) #}7m'F count = 0 eBTedSM?t While GetOperationCount(eID)>count 2{kfbm-89t GetOperation eID, count, op *rz(}(r If op.Type="ShiftZ" Then $lAb6e$n DeleteOperation eID,count \G=R hx f count=count-1 jfPJ5]Z End If ICbdKgLz count=count+1 /B@%pq Wend qb>r\bc qm8n7Z/ 'Set new z-shift ]a!; `m$ op.Type = "ShiftZ" dU>R<jl!$ op.val1 = tlens J
s<MJ4r>/ op.parent = parID g~hk-nXL. AddOperation eID, op /Np"J Print "Set lens thickness = " & tlens `J#xyDL6? FR,#s^kF '************************************************************************* 6a]f&={E 'Lens index of refraction K:
o|kd '************************************************************************* qVD!/;l eID = FindMaterial( "Lens" ) =R;1vUio GetModelMaterial eID, mat PtQ# @EP{VV mat.Nd = nlens QjjJtKz SetModelMaterial eID, mat XBWSO@M' Print "Set lens index of refraction = " & nlens '"]>`=R PP[)h,ZL* '************************************************************************* JeTrMa 2 'Pupil diameter 5@>4)dk\ '************************************************************************* B,vHn2W
eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &Wv`AoV D*T$ v
'Adjust pupil diameter (trimming volume inner hole) ,gL)~6!A E}b>7L&w SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" &>zy_) qe6C|W~n ' Adjust pupil location to just in front of the lens E0)mI)RW. parID = FindFullName( "Geometry.Arizona Eye" ) `k{ ff eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) FQ|LA[~ count = 0 Hu9-<upc& While GetOperationCount(eID)>count !OoaE* s GetOperation eID, count, op GkGC4*n If op.Type="ShiftZ" Then snTJe[^d DeleteOperation eID,count K!-&Zv count=count-1 :S99}pgY End If OZC/+"\, count=count+1 X\p`pw$ Wend JM+sHHs op.Type = "ShiftZ" uU[[[LQq op.val1 = taq-0.01 |Y8Mk2,s op.parent = parID i_9Cc$Qh< AddOperation eID, op zN)|g 'x45E.wYw Print "Set pupil diameter = " & pupilDiam /[nZ#zj!3 DNm7z[t{ 'Update AZ Eye subassembly Description LN~N
Fjs eID = FindFullName( "Geometry.Arizona Eye" ) C;)Xwm>e GetEntity eID, entity 9-a2L JI entity.Description = "Accommodation = " & A & "D" ,p*ntj{ SetEntity eID, entity VO @
4A6 xu"94y+ Update x<{;1F,k3 Print "DONE!" ek(kY6x: D,GPn%Wqi End Sub h$aew63 k67i`f= 如果屈光度是4,光瞳直径是4,则会输出如下数据: :_fjml/ _
r^90 Accommodation = 4 Diopters gf3u0' $ Pupil Diameter = 4 mm +9 16ZPk Set aqueous humor thickness = 2.81 `u p-m=zA Set anterior lens radius = 10.4 and conic constant = -2.375869 -
5o<Q'( Set posterior lens radius = -4.424557 and conic constant = -3.081019 _Qm7x>NT4 Set lens thickness = 3.927 `uNvFlP Set lens index of refraction = 1.42672 y?*[}S Set pupil diameter = 4 _>jrlIfc DONE! %2Xus9;k#
|