-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2026-01-20
- 在线时间1915小时
-
-
访问TA的空间加好友用道具
|
简介 #6[FGM '3 xvQFg 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。 )wQR2$x~ 9?:SxI;v 模型 <VS\z(K MS%xOB*6 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。 EX7gTf# B<T wTv Table 1. AZ眼睛模型的定义 a*0gd-e0@ 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. CP)x; /0>Cy\eN0 光源 !G.)%+Z I
$!Y 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 9s5gi+l_O ]O3[Te _'JKPD[ 图1. 光源和提示信息使用 bEfxu;Su3 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 V/j+Z1ZW #(FG+Bk 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 n a])bBn ]i3 2-8% 图2. 字母F光源的设定方法光 KGS=(z %,g6:Zc@ 图3. 字母F在视网膜上位置点列图 {<5rbsqk 视网膜的散射 m/r4f279 2u4aCfIx 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ,~`R{,N` ,kfUlv= <?5 ,3`V 图4. 视网膜朗伯散射设定 LGGC=;{} 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 &uI`Xq. dWwh?{n UbE*x2N 图5. 视网膜重点采样规格设定 x>m_ v 脚本 X3
D(2W )=V0 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: 8q{
%n m{gx\a.5 图6. 用户对话框的创建与编辑 'z0@|a 图7. 用户对话框编辑器 nKC$
KC 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。 D|}
y{~ 余下的脚本计算与屈光度有关的所有参数。 Z.Z+cFi h1} x2 分析 r%A- 4<CHwIRHY 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 }A;J-7g6 h lD0^8S 图7. 字母F在视网膜上颜色分析 3yn>9qt 脚本代码 H@GiHej q|0Lu Option Explicit 'Remove this to enable non-dimensioned variables to be used. (E )@@p7,: rTT Uhd Dim entity As T_ENTITY ^noKk6Aaa Dim op As T_OPERATION pwU
l&hwte Dim mat As T_MODELMATERIAL WQv%57+
Dim A As Double O$ui:<]dS Dim pupilDiam As Double ,E2Tw-% Dim eID As Long gF,9Kv~ Dim parID As Long #9uNJla Dim count As Integer BR*,E~% Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double E8j>Toz Dim tlens As Double, nlens As Double e$}x;&c Q Dim curv As Double, conic As Double cl:h'aG Dim ok As Long }w^Hm3Y^& p3>p1tC Sub Main s ki'I =S7Xj`/ '用户输入对话框 9;KQ3.Fa}q Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 h BD .IB TextBox 220,21,40,21,.TextBox1 'default: 0 ^u`1W^> Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *o <S{ OKButton 40,91,90,21 yU]NgG=z:- CancelButton 190,91,90,21 f-&4x_5 Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 D#R5G
TextBox 220,49,40,21,.TextBox2 'default: 4 Gv?3T Am8 End Dialog ".Z|zt6C Dim dlg As UserDialog IGqg,OEAp 1\K%^<QY ok = Dialog (dlg) ZqH.$nXP |#G.2hMFr If ok=0 Then 'cancel button was pressed <=2\xJfxB Print "Execution cancelled." Hy}oSy26 End DtLga[M End If =?hGa;/rb If[4]-dq 'Assign accommodation and pupil diameter & use defaults if field left empty uL| Wuq If dlg.TextBox1 = "" Then 91'i7&~xdG A = 0 'Default accommodation X}x"+#\<@ Else sI>I A = CDbl(dlg.TextBox1) \>,[5|GU End If &[QvMh 6Q\0v If dlg.TextBox2 = "" Then *l\wl @{ pupilDiam = 4 'Default pupil diameter cCOw7< Else 5Us$.p pupilDiam = CDbl(dlg.TextBox2) RN2^=$'. End If KWwEK] !7)` g i Print " " UqHk2h- Print "Accommodation = " & A & " Diopters" v;_m1UpuW Print "Pupil Diameter = " & pupilDiam & " mm" pK/r{/>r R.nAD{>h* ' Calculate new parameters with accommodation kF{'?R5w taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness gt]k#(S oN3DM; Rant = 12.0 - 0.4*A 'Radius of anterior lens qaE>]) CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens 'YKyY:eZ V
,#
|\ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens =zaf{0c CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens Ss>ez8q ?w/i;pp<, tlens = 3.767 + 0.04*A 'Lens thickness ~@Yiwp\" C1/qiSHsh nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction P D,s,A haTmfh_| 'Adjust parameters to account for accommodation 5D9n>K4| gl.uDO%. '************************************************************************* *GUQz 'Aqueous thickness (Position of Lens) | R\PQ/) '************************************************************************* barY13)$U eID = FindFullName( "Geometry.Arizona Eye.Lens" ) LsW7JIQd GetCustomElement eID, entity >aw`kr ;iB9\p$K) parID = FindFullName( "Geometry.Arizona Eye" ) [Q0n-b,Q *yX5g,52-| ' Delete any shift(s) in z ,oin<K count = 0 ,#/%Fn%T While GetOperationCount(eID)>count %X|fp{C GetOperation eID, count, op ]{.iv_I If op.Type="ShiftZ" Then D5Z@6RVt DeleteOperation eID,count E}qW' count=count-1 *P:!lO\| End If x`3F?[#l count=count+1 O%Hc%EfG Wend #3~ #`& r$Gz 'Set new shift in e@j&c:p(Y op.Type = "ShiftZ" s:O8d L
/ op.val1 = taq ?:$aX@r op.parent = parID frh!dN
AddOperation eID, op x^sSAI( Print "Set aqueous humor thickness = " & taq-0.55 VoG_'P fpPB_P{Ua '************************************************************************* dp|VQWCq 'Radius and conic constant of anterior lens Z=KHsMnB '************************************************************************* FN+x<VXo( eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &eA!h GetConic eID, entity, curv, conic f)_k_ < XJSI/jpa@ SetConic eID, entity, 1/Rant, CCant +<})`(8 Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ._X|Ye9/ !_P-?u '************************************************************************* , tEd> 'Radius and conic constant of posterior lens 7QXp\<7 '************************************************************************* U,g)N[| eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) hJc^NU5 GetConic eID, entity, curv, conic dEu\}y| a#pM9n~a SetConic eID, entity, 1/Rpost, CCpost xo
GX&^= Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 8
*Y(wqH )x<oRHx] '************************************************************************* ?PSJQ3BC| 'Lens thickness (Position of posterior lens surface) #qcF2&a% '************************************************************************* 6uu49x_^L4 s
+Q'\? parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3vc2t6S%* G<m6Sf ' Delete any z-shift(s) o4qB0h count = 0 qX"m"ko While GetOperationCount(eID)>count qKjUp" GetOperation eID, count, op 3?x}48 If op.Type="ShiftZ" Then zI&). DeleteOperation eID,count X[E!q$ag count=count-1 P3_&( End If 3E$h
W count=count+1 FdE9k\E#/) Wend p5V.O20 ] <y3;T\~ 'Set new z-shift *7`amF- op.Type = "ShiftZ" +01bjM6F_1 op.val1 = tlens 5uAUi=XA>S op.parent = parID jQX9KwSP AddOperation eID, op )J(@e4;Rv Print "Set lens thickness = " & tlens #W2#'J:l E/Adi^ '************************************************************************* +9NI=s6 'Lens index of refraction q+1SU6x'm '************************************************************************* (U_dPf eID = FindMaterial( "Lens" ) dz"HO!9 GetModelMaterial eID, mat s g6e%
5 7: .bqRu mat.Nd = nlens d$<1Ma} SetModelMaterial eID, mat $1.l| Print "Set lens index of refraction = " & nlens JrJTIUf_ &B@qb?UE1 '*************************************************************************
3F\UEpQ 'Pupil diameter m'"Ra- '************************************************************************* Vd+5an? eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 'U{6LSaCb G1S:hw%rp 'Adjust pupil diameter (trimming volume inner hole) IEQ6J}L *OR(8; SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Mw{skK>b *rmwTD" ' Adjust pupil location to just in front of the lens W}.p, d parID = FindFullName( "Geometry.Arizona Eye" ) G}0fk]%\: eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) nTH!_S>b(Y count = 0 7p+uHm While GetOperationCount(eID)>count .9u,54t GetOperation eID, count, op
|7wiwdD" If op.Type="ShiftZ" Then od`:w[2\ DeleteOperation eID,count O/{W:hJjd count=count-1 2@+MT z End If I3D#wXW count=count+1 DOGg=`XK1 Wend #7dM % op.Type = "ShiftZ" r/BiR0$E op.val1 = taq-0.01 Nk/Ms:57y op.parent = parID M$AQZ')9 AddOperation eID, op d+Bz
pS@p *l\vqgv.Z Print "Set pupil diameter = " & pupilDiam GcA!I!j/ Ykt(%2L 'Update AZ Eye subassembly Description $jKeJn8, eID = FindFullName( "Geometry.Arizona Eye" ) Q=cbHDB GetEntity eID, entity
G##^xFx entity.Description = "Accommodation = " & A & "D" %Q[+bN[/ SetEntity eID, entity gKay3}w ||vQW\g Update `<kV)d%xEF Print "DONE!" K#],4OG 26\*x End Sub -"Q[n,"Y D:Y`{ { 如果屈光度是4,光瞳直径是4,则会输出如下数据: |
QI-gw `%M}
:T Accommodation = 4 Diopters w=H4#a?fc Pupil Diameter = 4 mm dwt<s[k Set aqueous humor thickness = 2.81 q;a#?Du o Set anterior lens radius = 10.4 and conic constant = -2.375869 hhvP*a_J Set posterior lens radius = -4.424557 and conic constant = -3.081019 bUi@4S Set lens thickness = 3.927 .1C|J Set lens index of refraction = 1.42672 :j m|) Set pupil diameter = 4 |Zo_x}0 DONE! Oz1ou[8k
|