-
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 JIeKp7;^ 01bBZWX 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。 /]pBcb|< V5$J 模型 rl#[HbPM VXr'Z 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 Ln~Z_! G's
>0 Table 1. AZ眼睛模型的定义 ci]IH]x 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. v]`}T/n +C`h*%BW 光源 Vn:BasS% -Ucj|9+(a
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 'FVh/};Y.D )"Ef* /+ n.}A
:Z 图1. 光源和提示信息使用 )C
\ %R 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 R4xoc;b \?n4d#=$o 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。 2L=+z1%I 4}mp~AXy;z 图2. 字母F光源的设定方法光 Jxyeh1zqB KC@F"/h`/ 图3. 字母F在视网膜上位置点列图 ^Kvbpi, 视网膜的散射 ']'H8Y-M dy>iIc> 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。 |$$gj[+^ N*d
)<8_ hYm$Sx(= 图4. 视网膜朗伯散射设定 ;'^5$q 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。 p#-;u1-B bf~gWzA Z_%9LxZlyj 图5. 视网膜重点采样规格设定 +kh#Jq. 脚本 Gp}:U>V) x2@Q5|a 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: xR9<I:^& /qf2LO'+ 图6. 用户对话框的创建与编辑 wI\
n%# 图7. 用户对话框编辑器 Z^Y_+)=s 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。 BU\P5uB!V 余下的脚本计算与屈光度有关的所有参数。 - v\n0Jt %}t<,ex(yO 分析 R-lB.9e#M eRI'pi[#. 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 1J(` kQ)c &C_0JyT 图7. 字母F在视网膜上颜色分析 ([Gb]0 脚本代码 Gz>M Y4+G 6\8
lx|w Option Explicit 'Remove this to enable non-dimensioned variables to be used. `RRC8 ]l *rs@6BSj Dim entity As T_ENTITY ROWb:tX} Dim op As T_OPERATION v0~'`*|& Dim mat As T_MODELMATERIAL Y[oNg>Rz Dim A As Double RR*eq.; Dim pupilDiam As Double jzRfD3_s Dim eID As Long r9),F.6, Dim parID As Long |AY`OVgcKD Dim count As Integer /h)_Q;35S; Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double W(5et5DN, Dim tlens As Double, nlens As Double Eb9 eEa<W Dim curv As Double, conic As Double B hO*Pfs Dim ok As Long ,4RmT\%T ccLTA Sub Main ;<aT|4 R`)^eqB '用户输入对话框 D..dGh.MY Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 _$wXHONt TextBox 220,21,40,21,.TextBox1 'default: 0 ?Cg",k ' Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 jm|x=s3}h OKButton 40,91,90,21 b^SQCX+P CancelButton 190,91,90,21
@P1#) Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 pS1f y] TextBox 220,49,40,21,.TextBox2 'default: 4 6 WD( End Dialog 7~gIOu Dim dlg As UserDialog zv1#PfO@) `y1nex-0 ok = Dialog (dlg) KW3Dr`A C'6yt If ok=0 Then 'cancel button was pressed }8H_^G8 Print "Execution cancelled." 9VEx0mkdd End
;oej~ End If \O*8% {_ &*"bK 'Assign accommodation and pupil diameter & use defaults if field left empty D)XV{Wit If dlg.TextBox1 = "" Then h($XR+!# A = 0 'Default accommodation .7h:/d
Y: Else 4Nz@s^9 A = CDbl(dlg.TextBox1) ;zMZ+GZ?;+ End If @
m' zm: {8!\aYI If dlg.TextBox2 = "" Then *.4VO+^ pupilDiam = 4 'Default pupil diameter ,Z2fVz~9 Else k<bA\5K pupilDiam = CDbl(dlg.TextBox2) <{t*yMr End If **oaR 8'niew
5d Print " " mes/gqrJ1I Print "Accommodation = " & A & " Diopters" |OgtAI9 Print "Pupil Diameter = " & pupilDiam & " mm" KdBE[A-1^M cO&(&*J r ' Calculate new parameters with accommodation scXY~l]I* taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness 2J>v4EWC ~9[^abz Rant = 12.0 - 0.4*A 'Radius of anterior lens 1
P0)La# CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens hI+mx S:.Vt&+NJ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens ,Pq@{i# CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens !>n^ ;u dX720/R tlens = 3.767 + 0.04*A 'Lens thickness @X$~{Vp__ !foiGZ3g nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction Hp#IOsP~ +>w %j&B 'Adjust parameters to account for accommodation i4Ps#R_wx T:~c{S4& '************************************************************************* uR;m<wPH,f 'Aqueous thickness (Position of Lens) ji8)/ '************************************************************************* }K
rQPg
eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Wu{cE;t GetCustomElement eID, entity (IE\}QcK xcVF0%wVC parID = FindFullName( "Geometry.Arizona Eye" ) ^]{)gk8P~2 sQIzcnKB ' Delete any shift(s) in z \&KfIh8 count = 0 bhqV2y*' While GetOperationCount(eID)>count \$Jz26
-n GetOperation eID, count, op 2^V/>|W>w If op.Type="ShiftZ" Then pA~eGar_J DeleteOperation eID,count O/N
Ed)H! count=count-1 |qp^4vq.p End If .%\lYk] count=count+1 =!V-V}KK- Wend E1"H(m&6 PQ}owEJ2eM 'Set new shift in F\)?Ntj)>@ op.Type = "ShiftZ" $G,#nh2 oD op.val1 = taq nQHQVcDs8 op.parent = parID ?Dr_WFNjO AddOperation eID, op 8|U-{"!O? Print "Set aqueous humor thickness = " & taq-0.55 /x2MW5H x%$as; '************************************************************************* @hz~9AII9 'Radius and conic constant of anterior lens [f8mh88r '************************************************************************* 3-%F)@n eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Qf$3!O}G GetConic eID, entity, curv, conic '1f:8 Bh%Yu*.f SetConic eID, entity, 1/Rant, CCant I<&(Dg|XQ Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ,cF
$_7M >3,t`Z: '************************************************************************* 6u6,9VG, 'Radius and conic constant of posterior lens 2Nau]y]= '************************************************************************* '^6jRI,
eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) H[;\[3 GetConic eID, entity, curv, conic =KCAHNr4? vIK+18v7 SetConic eID, entity, 1/Rpost, CCpost Jh6 z5xUV Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }Q<cE$c SI~MTUqt '************************************************************************* =Felo8+ 'Lens thickness (Position of posterior lens surface) bS2)L4MQY '************************************************************************* ej^pFo *D_p FS^l parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (&=gM )LRso>iOO ' Delete any z-shift(s) M{ count = 0 Y \oz9tf8 While GetOperationCount(eID)>count Q=}U GetOperation eID, count, op wV&UB@ If op.Type="ShiftZ" Then `yXJaTbo DeleteOperation eID,count vf&Sk` count=count-1 Mu>WS)1lS End If l`M7a9*U count=count+1 j3kcNb Wend \ld{Z;e A2xfNY< 'Set new z-shift 7c7:B2Lq op.Type = "ShiftZ" V]fsjpvlmr op.val1 = tlens Ug=)_~ op.parent = parID u@ psVt AddOperation eID, op +kdZfv> Print "Set lens thickness = " & tlens Q9C;_Up fMSB '************************************************************************* S @WzvM 'Lens index of refraction YS|Ve*t(L= '************************************************************************* q<2b,w== eID = FindMaterial( "Lens" ) tXu_o6] GetModelMaterial eID, mat rF>7
>wq z}sBx9; mat.Nd = nlens B?|url6h SetModelMaterial eID, mat Pm} Print "Set lens index of refraction = " & nlens *(pmFEc G|,'6|$jE '************************************************************************* 8`?vWJS 'Pupil diameter _1sjsGp> '************************************************************************* ~UhTy~jya eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 2uajK..b _R] qoUw; 'Adjust pupil diameter (trimming volume inner hole) q,->E<8 +:#x!i;W8[ SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" =4H"&Eu{ <T0+-]i ' Adjust pupil location to just in front of the lens YlP8fxS parID = FindFullName( "Geometry.Arizona Eye" ) =u,8(:R]s eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) k#Bq8d count = 0 +_E\Omcw While GetOperationCount(eID)>count wFHbz9|@I GetOperation eID, count, op q/N1q& If op.Type="ShiftZ" Then JF%_8Ye5 DeleteOperation eID,count hCX_^% count=count-1 A['0~tOP End If }1)tALA count=count+1 DGY?4r7>y Wend c&rS7% op.Type = "ShiftZ" lM N3;}K op.val1 = taq-0.01 I_\#( op.parent = parID ]=EYju@ AddOperation eID, op =SEgv;#KZ~ tXWhq Print "Set pupil diameter = " & pupilDiam 2xEG s Q '9R.$,N 'Update AZ Eye subassembly Description k9|8@3(h eID = FindFullName( "Geometry.Arizona Eye" ) =,4iMENm! GetEntity eID, entity =Co[pt entity.Description = "Accommodation = " & A & "D" ?-HLP%C(' SetEntity eID, entity m+7/ebj{A ]@rt/ eX Update 3gcDc~~= Print "DONE!" %Uz
5Ve 5?{ytNCY End Sub =bwuLno> btV
Tt5 如果屈光度是4,光瞳直径是4,则会输出如下数据: $afE=
qC* R3`h$`G Accommodation = 4 Diopters l)^sE) Pupil Diameter = 4 mm 9BA*e-[ Set aqueous humor thickness = 2.81 1m5=Nu Set anterior lens radius = 10.4 and conic constant = -2.375869 c%bGVRhE Set posterior lens radius = -4.424557 and conic constant = -3.081019 MMYV8;c Set lens thickness = 3.927 9jC>OZ0s Set lens index of refraction = 1.42672 ee+*&CT) Set pupil diameter = 4 ER ^#J** DONE! A3Lfh6O
|