-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2025-12-12
- 在线时间1894小时
-
-
访问TA的空间加好友用道具
|
简介 {K/xI LR"7e 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][Tb0Ox $O\]cQD`u 模型 d,j)JnY3V ?#ywUEY* 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。 {;JFoe+ _XI,z0( Table 1. AZ眼睛模型的定义 BBl9<ne$ 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. akgvV~5 SvQj'5~< 光源 "!Hm.^1 WO+>W+|N 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。 o1&Oug OF!n}.O( Et)j6xz/F 图1. 光源和提示信息使用 #'y^@90R 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。 q\fai^_ UX?S#:h 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。 `DP4u\6_ yfAh= 图2. 字母F光源的设定方法光 Jy]}'eE?pr ~c>]kL(, 图3. 字母F在视网膜上位置点列图 eI5W; Q4 视网膜的散射 cT'<,#^/ :C#(yp 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。 :&O6Y-/B :YmFQ>e? Iw</X}#\ 图4. 视网膜朗伯散射设定 t@BhosR- 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。 m&6)Vt dJmr!bN\; nqib`U@" 图5. 视网膜重点采样规格设定 =l}XKl-> 脚本 jsw0"d( l;;"v) C8 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: W
-5wjc .W0;Vhw" 图6. 用户对话框的创建与编辑 >=L<3W1 图7. 用户对话框编辑器 p=f8A71 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。 "nn>I}jK 余下的脚本计算与屈光度有关的所有参数。 7{u1ynt %4h$/~ 分析 #)<WQZ) Sh o] ~)XX 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 e5m-7{h@ Z<[f81hE& 图7. 字母F在视网膜上颜色分析 T_4y;mf!@O 脚本代码 ^36m$J $ Q-$EBNz Option Explicit 'Remove this to enable non-dimensioned variables to be used. OQ by=} A ZfWF2%]< Dim entity As T_ENTITY rp,PhS Dim op As T_OPERATION UE%~SVi.# Dim mat As T_MODELMATERIAL <0^L L Dim A As Double /Os;, g Dim pupilDiam As Double *Zk$P.] Dim eID As Long $N17GqoC Dim parID As Long !"
7ip9a Dim count As Integer |),3`*N Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double J~1=?</ Dim tlens As Double, nlens As Double 3Qoa?* Dim curv As Double, conic As Double Eza B}BLQ9 Dim ok As Long vKcc|# )|i]"8I Sub Main uSn<]OrZo` orr6._xw '用户输入对话框 SXm Hn.? Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ; Uf]-uS TextBox 220,21,40,21,.TextBox1 'default: 0 9A9yZl t Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 6 2#dSd}HG OKButton 40,91,90,21 @m(ja@YC CancelButton 190,91,90,21 |a[Id Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 uMM?s?q TextBox 220,49,40,21,.TextBox2 'default: 4 !TdbD56 End Dialog xO` O$ie Dim dlg As UserDialog {qjw
S1v bG[)r ok = Dialog (dlg) *u`[2xmuYf vB T]a If ok=0 Then 'cancel button was pressed ;bxL$1 Print "Execution cancelled." xr'gi(.o End d(8X?k.S End If $
-n?q w ]2o? Gnn@ 'Assign accommodation and pupil diameter & use defaults if field left empty I~P]_DmM If dlg.TextBox1 = "" Then W_P&;)E A = 0 'Default accommodation s.uV,E*wu Else sT|FgB A = CDbl(dlg.TextBox1) j_2yTz"G- End If ~^pV>>LX| *#2]`G) If dlg.TextBox2 = "" Then pSlosv(6 pupilDiam = 4 'Default pupil diameter a jyuk@ Else tHV81F1J pupilDiam = CDbl(dlg.TextBox2) ('7qJkV End If GH!Lu\y\ MehMhHY Print " " [#Y7iN& Print "Accommodation = " & A & " Diopters" XrD@q Print "Pupil Diameter = " & pupilDiam & " mm" xsIuPL#_ o?l9$"\sqb ' Calculate new parameters with accommodation BVk&TGa;[$ taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness S>s{t=AY~ %uWq)D4r Rant = 12.0 - 0.4*A 'Radius of anterior lens U4hFPK< CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens !E+. ( ZdjmZx%% Rpost = -5.224557 + 0.2*A 'Radius of posterior lens Xitsbf=Gg CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens G`1FD Sx", Zb tlens = 3.767 + 0.04*A 'Lens thickness +vh 4I ;"77?) nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction D[ -Gzqh >
R5<D'cEN 'Adjust parameters to account for accommodation orcPKCz|" i{
" g7 '************************************************************************* k&h3" 'Aqueous thickness (Position of Lens) {BA1C
( '************************************************************************* qz
.{[l eID = FindFullName( "Geometry.Arizona Eye.Lens" ) )LP=IT GetCustomElement eID, entity z|:3,$~sN vdLBf+Zi parID = FindFullName( "Geometry.Arizona Eye" ) CtO `t5 hH|moj] ' Delete any shift(s) in z LyB &u() count = 0 1D/9lR, While GetOperationCount(eID)>count r(#]Z GetOperation eID, count, op d?uN6JH9 If op.Type="ShiftZ" Then sD[G?X DeleteOperation eID,count YAvOV-L count=count-1 E0Y>2HOuL End If 0$~zeG" count=count+1 XpLK0YI Wend XpH]CF muc>4!Q 'Set new shift in p*_^JU(<p op.Type = "ShiftZ" ~rWys= op.val1 = taq Vk>m/" op.parent = parID 9Rg|o CP_ AddOperation eID, op 4._U Print "Set aqueous humor thickness = " & taq-0.55 [Pnk@jIk4 G2A^+R0\ '************************************************************************* GV1SKa 'Radius and conic constant of anterior lens B?cn5 '************************************************************************* <^APq8> eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Ob"48{w$ GetConic eID, entity, curv, conic X4"D Lt" t%`GXJb SetConic eID, entity, 1/Rant, CCant Sl?@c/Ng Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?=22@Q}g KG!W,tB '************************************************************************* $Z!$E,@c 'Radius and conic constant of posterior lens 1+f>tv '************************************************************************* F"k.1. eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) #@*;Y(9Ol GetConic eID, entity, curv, conic Ch~2w)HAA EPE9HvN SetConic eID, entity, 1/Rpost, CCpost P}AfXgr Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost z)Is:LhS &ZmHR^Flz '************************************************************************* Y2)2
tzr] 'Lens thickness (Position of posterior lens surface) {Gd<+tQg '************************************************************************* _.ny<r:g U=<d;2N# parID = FindFullName( "Geometry.Arizona Eye.Lens" ) COF_a% )_vE"ryThA ' Delete any z-shift(s) PW[NW-S`c count = 0 U',9t While GetOperationCount(eID)>count J(%Jg GetOperation eID, count, op LZ97nvK If op.Type="ShiftZ" Then Y_H|Fl^ DeleteOperation eID,count k|Hxd^^I count=count-1 HR/"Nwr End If :2qUel\PEC count=count+1 $!(J4v=X Wend b?p_mQKtZ w}OJ2^ 'Set new z-shift *5\k1-$ op.Type = "ShiftZ" V8aLPJ0_ op.val1 = tlens L7_qs+ op.parent = parID eX;Tufe*(Q AddOperation eID, op 3M;[.b Print "Set lens thickness = " & tlens ~F</s. &m>yY{be '************************************************************************* 4z_ >CiA 'Lens index of refraction X"S-f;b# '************************************************************************* N^G:m~> eID = FindMaterial( "Lens" ) 8f^QO: GetModelMaterial eID, mat PWwz<AI+ "1<>c/h mat.Nd = nlens ;Y&<psQeb SetModelMaterial eID, mat !L+4YA Print "Set lens index of refraction = " & nlens d:U2b"k=/u QWo_Zg0" '************************************************************************* wTpjM@F?J| 'Pupil diameter 9^;)~ G '************************************************************************* HG1)q\Xd eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) DE{tpN muAI$IRR 'Adjust pupil diameter (trimming volume inner hole) 36NENzK ]6`]+& SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" rRTAWAs%T b'D|p/)m0S ' Adjust pupil location to just in front of the lens
FmRCTH parID = FindFullName( "Geometry.Arizona Eye" ) WBo|0(# eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ` )9nBZ count = 0 W[5a'}OV While GetOperationCount(eID)>count ;1S~'B&1Q GetOperation eID, count, op i2a""zac If op.Type="ShiftZ" Then uxGY/Zf DeleteOperation eID,count 5 A/[x$q count=count-1 &\3k(j End If =@98Gl9! count=count+1 /rKdxsI* Wend c.-/e u^| op.Type = "ShiftZ" 20 j9~+ op.val1 = taq-0.01 Q7 dXTS4H op.parent = parID bN Ub AddOperation eID, op 7^{M:kYC! *rY@(| Print "Set pupil diameter = " & pupilDiam aoLYw 9 xQ4'$rL1d 'Update AZ Eye subassembly Description Y9b|lP7! eID = FindFullName( "Geometry.Arizona Eye" ) ]Iku(<*Ya GetEntity eID, entity mA ^[S.! entity.Description = "Accommodation = " & A & "D" th@a./h" SetEntity eID, entity "bO\Wt#Mf %i7bkdcwk Update @yBg)1AL Print "DONE!" %J*z!Fe8s ;#3l&HRKH1 End Sub *O>OHX ogcEv>0 如果屈光度是4,光瞳直径是4,则会输出如下数据: `$IuN* M;BDo(1 Accommodation = 4 Diopters &WSxg&YG)\ Pupil Diameter = 4 mm zJp}JO Set aqueous humor thickness = 2.81 CNC3">Dk~9 Set anterior lens radius = 10.4 and conic constant = -2.375869 hXsd12 Set posterior lens radius = -4.424557 and conic constant = -3.081019 #Y*?kTF Set lens thickness = 3.927 7j9:s>D Set lens index of refraction = 1.42672 >900I4]I Set pupil diameter = 4 kB|jN~ DONE! E7A psi4]
|