-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2026-01-28
- 在线时间1922小时
-
-
访问TA的空间加好友用道具
|
简介 kN'|,eKH4 J>f
/u:. 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。 E0sbU<11 <ldid]o
# 模型 )x$!K[= z{Hz;m:*_ 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 r :fwrC &M0o&C-1/ Table 1. AZ眼睛模型的定义 EsT0"{ 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 06PhrPVa!\ C$KaT3I 光源 qJ\X~5{ iP~sft6 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。 I?f"<5[0 !&@2 Ix( 6 图1. 光源和提示信息使用 D"`%|`O 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。 k
TF z_*6. Nawp t% 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。 i{<8
hLO b cC\ 图2. 字母F光源的设定方法光 n
(OjjRm X32RZ9y 图3. 字母F在视网膜上位置点列图 /DLr( 视网膜的散射 8&?^XcJ*x ,)Yao;Cvd 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。 2;&mkcK' ]MC/t5vC u
$`^H:Djr 图4. 视网膜朗伯散射设定 \V._Z>] 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 -Bl/4p uEBQoP2 5kK=S 图5. 视网膜重点采样规格设定 ^/G?QR 脚本 Xfj)gPt} 7^c2e*S 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: g+:$X- r OlIT|bzkb 图6. 用户对话框的创建与编辑 l#b:^3 图7. 用户对话框编辑器 4DvdEt 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。 OMl8 a B9 余下的脚本计算与屈光度有关的所有参数。 bAUHUPe [0K=I64
z 分析 #1MKEfv(~ A3xbT\xdg 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 {PL,VY)Z QyTh!QM~` 图7. 字母F在视网膜上颜色分析 "K8nxnq 脚本代码 C=8H)Ef,l O2C6V>Q; Option Explicit 'Remove this to enable non-dimensioned variables to be used. MY&<)|v\ pH^ z Dim entity As T_ENTITY <|otZJ'2r Dim op As T_OPERATION #U\$@4D Dim mat As T_MODELMATERIAL 6tX.(/+L Dim A As Double GX7VlI[ Dim pupilDiam As Double x 96}#0' Dim eID As Long 5Lw{0uLr Dim parID As Long KvGbDG Dim count As Integer %@>YNPD`E Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double DQcWq'yY^ Dim tlens As Double, nlens As Double ?%93b ,7 Dim curv As Double, conic As Double JW-|<CJ Dim ok As Long #&k8TY ?b5H
2W Sub Main
j|ozGO T{ok +$w2 '用户输入对话框 U8E0~[y' Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 !`Le`c TextBox 220,21,40,21,.TextBox1 'default: 0 r;9z5' Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 f7.m=lbe OKButton 40,91,90,21 ZH% we CancelButton 190,91,90,21 Sq<3Rw Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |%-YuD TextBox 220,49,40,21,.TextBox2 'default: 4 cFw3Iw"JJ End Dialog ,b$z!dvhl Dim dlg As UserDialog t~q?lT g2A"1w<-AH ok = Dialog (dlg) R \ia6 kw3+>{\ If ok=0 Then 'cancel button was pressed rj}(muM,R Print "Execution cancelled." FbmsN)mv!% End m!;G/s* End If !W(`<d]68: O6/xPeak 'Assign accommodation and pupil diameter & use defaults if field left empty S3QaYq"v If dlg.TextBox1 = "" Then G<|:605 A = 0 'Default accommodation sLNNcj(Cy> Else lz-
iCZ A = CDbl(dlg.TextBox1) 'g2vX&=$A End If \PzN XQ$ W5|j1He& If dlg.TextBox2 = "" Then (N7O+3+G pupilDiam = 4 'Default pupil diameter 5 1"8Py Else _Cj(fFL pupilDiam = CDbl(dlg.TextBox2) Q]^Yi1PbS End If PF m\[2 Xty#vI Print " " .ByU Print "Accommodation = " & A & " Diopters" O hi D Print "Pupil Diameter = " & pupilDiam & " mm" ^zHRSO 2?*||c==* ' Calculate new parameters with accommodation BK*z 4m taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness wz h.$?~ 72u db^ Rant = 12.0 - 0.4*A 'Radius of anterior lens p+vh[+yp CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens U[ bgu#P; 8sH50jeP Rpost = -5.224557 + 0.2*A 'Radius of posterior lens j!7Qw 8 CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens 2Sjt=LOc=" >GmN~"iJ tlens = 3.767 + 0.04*A 'Lens thickness t GC2
^a#~ =E!x~S;N nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction g9`[Y~ "U*5Z:8?9 'Adjust parameters to account for accommodation B 2Qp} vkuc8 li '************************************************************************* dGU8+)2cn 'Aqueous thickness (Position of Lens) HZ{n&iJ '************************************************************************* H@Q` eID = FindFullName( "Geometry.Arizona Eye.Lens" ) UDMyyVd GetCustomElement eID, entity SYeE) mI
ZJ9x6|q parID = FindFullName( "Geometry.Arizona Eye" ) \@8*T S =tn Tdp0F ' Delete any shift(s) in z RT/qcS^Oz count = 0 b9DR%hO: While GetOperationCount(eID)>count nGns}\!7' GetOperation eID, count, op /h7.oD8CU If op.Type="ShiftZ" Then ODek%0= DeleteOperation eID,count ~GA8_B count=count-1 5N1}Ns End If p&\K9hfi count=count+1 e6 2y Wend BKX9SL] >(OYK}ZN 'Set new shift in \q,s?`+B op.Type = "ShiftZ" i%MA"I\9 op.val1 = taq dqxd3,Z op.parent = parID L_k9g12 AddOperation eID, op %Ci^*zb Print "Set aqueous humor thickness = " & taq-0.55 O)1E$#~ j %H`0 '************************************************************************* F3Dt7q 'Radius and conic constant of anterior lens bNXAU\M^ '************************************************************************* nPOO3!<{ eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 3p&jLFphL GetConic eID, entity, curv, conic /p 5=i VKNp,Lf SetConic eID, entity, 1/Rant, CCant .&PzkqWZ Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant V~[:*WOX Yg&`
U^7]B '************************************************************************* gApz:K[l 'Radius and conic constant of posterior lens f1J%]g! '************************************************************************* 6g~+( ({lQ eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @mNJ=mEV GetConic eID, entity, curv, conic JjQVzkE RG&6FRoq SetConic eID, entity, 1/Rpost, CCpost [%?y( q Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }PZ=`w*O 'W(xgOP1 '************************************************************************* !UcOl0"6 'Lens thickness (Position of posterior lens surface) 4w;~4#ZPp '************************************************************************* T
.hb#oO $kl$D"*0 parID = FindFullName( "Geometry.Arizona Eye.Lens" ) nP;;MX:B -X8eabb ' Delete any z-shift(s) LipxAE?O count = 0 k}U
JVH21k While GetOperationCount(eID)>count )88nMH- GetOperation eID, count, op Um\0i;7 ~4 If op.Type="ShiftZ" Then ;s}3e#$L DeleteOperation eID,count $rB6< count=count-1 i.M2E$b| End If lQL:3U0DjU count=count+1 R8 jovr Wend ($SLb6 dyO E6Ex 'Set new z-shift GS4_jvD- op.Type = "ShiftZ" Pr/]0<s op.val1 = tlens 6c &Y op.parent = parID :Eo8v$W\RB AddOperation eID, op V7@
{D Print "Set lens thickness = " & tlens { 8p\Y VMF|iB '************************************************************************* Onw24& 'Lens index of refraction ]Uh1l.O '************************************************************************* 6v>z h eID = FindMaterial( "Lens" ) oCuV9dA. GetModelMaterial eID, mat 8^vArS; o%qkq K1 mat.Nd = nlens 7kd|K
b( SetModelMaterial eID, mat CL1;Inzl Print "Set lens index of refraction = " & nlens xqv[?
? Ow)R|/e/ '************************************************************************* tN2 W8d 'Pupil diameter (3W&AM '************************************************************************* |[LE9Lq/ eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ?bI?GvSh D:m#d.m 'Adjust pupil diameter (trimming volume inner hole) FUqt)YHi ~-<:+9m SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 75AslL?t P7r4ePtLk{ ' Adjust pupil location to just in front of the lens eXG57<t ON parID = FindFullName( "Geometry.Arizona Eye" ) U|?,N0%Z1 eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Rsn^eR6^ count = 0 "@)lH While GetOperationCount(eID)>count zo44^=~% GetOperation eID, count, op 6#|qg*OS If op.Type="ShiftZ" Then mPG7Zy$z DeleteOperation eID,count vi|Zit count=count-1 Ay%:@j(E End If j)";:v count=count+1 n1 v,#GE Wend afUTAP@ op.Type = "ShiftZ" Rcf=J){D6 op.val1 = taq-0.01 &I)\*Ue2t op.parent = parID Nb1J ~v AddOperation eID, op HfZtL Abf1"#YImy Print "Set pupil diameter = " & pupilDiam j+Zt.KXjT 9wMEvX70 'Update AZ Eye subassembly Description tW(+xu36 eID = FindFullName( "Geometry.Arizona Eye" ) +?V0:Kz] GetEntity eID, entity )Mi'(C; entity.Description = "Accommodation = " & A & "D" r<|nwFJ SetEntity eID, entity -[$&s FD F.0d4:A+ Update N&x:K+Zm. Print "DONE!" ]QS](BbD: ?K<ZkYw? End Sub BSDk9Oc zX~}]?|9 如果屈光度是4,光瞳直径是4,则会输出如下数据: [Xh\mDU. ugxw!cj Accommodation = 4 Diopters V{GXc:= Pupil Diameter = 4 mm [-58Ezyr Set aqueous humor thickness = 2.81 HlRAD|]\ Set anterior lens radius = 10.4 and conic constant = -2.375869 ;
8E; Set posterior lens radius = -4.424557 and conic constant = -3.081019 Ut_mrb+W Set lens thickness = 3.927 6(.H3bu Set lens index of refraction = 1.42672 <I1y Set pupil diameter = 4 w+Vk3c5uI) DONE! !qw4mN
|