Arizona眼睛模型
简介 \mZB*k)+ $oJjgA xcZ 人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 v?}rA %so 'e6J&X 模型 4hYK$!"r 7jr+jNsowj 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。 qxcTY|& flz7{W
Table 1. AZ眼睛模型的定义 OB++5Wd 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. 9ph>4u(R 7\ X_%SM % 光源 =4L%A=]` ?X\uzu 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。 U lCw{:#F -=n!k^?lK +Y2D @K?)
图1. 光源和提示信息使用 ?T,a(m<i{ 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。 n0t+xvNDF_ sn
Ou 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。 HdTB[( /g8nT1k
图2. 字母F光源的设定方法光 jaIcIc=Pf r=xec@R]*
图3. 字母F在视网膜上位置点列图 K,+z^{Hvh 视网膜的散射 &x4*YMh '}OAl 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"7" i h\5~&}Hp *g9VI;X
图4. 视网膜朗伯散射设定 A+}O~,mxP8 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。 'R#MH K.Cx 9 MlLM
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图5. 视网膜重点采样规格设定 gt=@v()) 脚本 k4!p))ql T hVq5 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: (Zej\lEN -zZb]8\E
图6. 用户对话框的创建与编辑 .&Sjazk0XO
图7. 用户对话框编辑器 1_8@yO 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。 WDr=+=Zj 余下的脚本计算与屈光度有关的所有参数。 aU$8 0 Mp^G7JY, 分析 Ci[Ja#p7$h HIvSh6|0p 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 e:.D^GFi
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图7. 字母F在视网膜上颜色分析 '#yIcV$ 脚本代码 f1B t6|W% B->oTC`5 Option Explicit 'Remove this to enable non-dimensioned variables to be used. ,,g: x cnDF`7xrT Dim entity As T_ENTITY BFqM6_/J Dim op As T_OPERATION DZ:$p. Dim mat As T_MODELMATERIAL DweF8c Dim A As Double kkOjAp{<t Dim pupilDiam As Double dV^ck+ Dim eID As Long SPvKq=, Dim parID As Long +xU=7chA Dim count As Integer <2LUq@Pg Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double {+gK\Nz Dim tlens As Double, nlens As Double XAB/S8 e Dim curv As Double, conic As Double ?9T,sX: Dim ok As Long @mcP- 0OnqKgf Sub Main A>)W6|m| Y+EwBg)co '用户输入对话框 _+Uf5,.5yU Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 7p{2&YhB TextBox 220,21,40,21,.TextBox1 'default: 0 ,0?3k Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 b86c[2 OKButton 40,91,90,21 20M]gw] CancelButton 190,91,90,21 m$g{& Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Hx9lQ8 TextBox 220,49,40,21,.TextBox2 'default: 4 5X9*K End Dialog H.O&seY Dim dlg As UserDialog *N](Xtbj TUQe.oAi ok = Dialog (dlg) !3"Hn
@Dd ( If ok=0 Then 'cancel button was pressed )$O'L7I n& Print "Execution cancelled." 7+$P6[* End Q.fD3g End If oCKn iH-(_$f; 'Assign accommodation and pupil diameter & use defaults if field left empty ;v~xL!uQ If dlg.TextBox1 = "" Then iP?lP= M A = 0 'Default accommodation 2p*L~! iM Else uzT>|uu$ A = CDbl(dlg.TextBox1) l i%8X. End If j$k/oQ Wf&i{3z[ If dlg.TextBox2 = "" Then C1-Jj_XQ. pupilDiam = 4 'Default pupil diameter *[b~2 Else h~#.s*0.F pupilDiam = CDbl(dlg.TextBox2) v5L#H=P End If P_Exh]P %,udZyO3uR Print " " py\/m] Print "Accommodation = " & A & " Diopters" %kk~qvW Print "Pupil Diameter = " & pupilDiam & " mm" "ZG2olOqLI @nM+*0
$d ' Calculate new parameters with accommodation Gx(%AB~9$ taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness ?1H>k<Jp %vU*4mH Rant = 12.0 - 0.4*A 'Radius of anterior lens 92^Dn`g CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens p8z"Jn2P B,A\/%< Rpost = -5.224557 + 0.2*A 'Radius of posterior lens +F^X1 CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens oXGP6# (=tu~ ^ tlens = 3.767 + 0.04*A 'Lens thickness @SAJ*hfb0 ^>h2.AJ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction n:JG+1I >yr3C 'Adjust parameters to account for accommodation QaAMiCZFR ?xo<Fv '************************************************************************* l
i2/"~l 'Aqueous thickness (Position of Lens) z_:r&UP`" '************************************************************************* 5:l"* eID = FindFullName( "Geometry.Arizona Eye.Lens" ) _/F}y[B7d GetCustomElement eID, entity wKy4Ic+RV P1"g62R parID = FindFullName( "Geometry.Arizona Eye" ) 'V*8'? ^I!gteU; ' Delete any shift(s) in z u6P U(f count = 0 *G,r:Bnb While GetOperationCount(eID)>count !)uXCg9U GetOperation eID, count, op PML84*K - If op.Type="ShiftZ" Then 2Zi&=Zj" DeleteOperation eID,count T!Uf
PfEI count=count-1 'h{DjNSM
End If ~VJP:Y{[ count=count+1 :$oi P Wend Y1 6pT Mm#=d?YUHJ 'Set new shift in q<A,S8'm op.Type = "ShiftZ" rXnG"A op.val1 = taq DZX4c 2J op.parent = parID _2Fa.gi AddOperation eID, op b/eo]Id ] Print "Set aqueous humor thickness = " & taq-0.55 SrXuiiK M,N(be- '************************************************************************* 9;EY3[N 'Radius and conic constant of anterior lens Redxg. P '************************************************************************* Q9
RCN<! eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 0"=}d y GetConic eID, entity, curv, conic Rj,M|9Y)o ]\:l>< SetConic eID, entity, 1/Rant, CCant )jN fQ!?/ Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8R.`* JPS<e*5 '************************************************************************* XBHv V05mv 'Radius and conic constant of posterior lens OTwXc*2u] '************************************************************************* ij1g2^],4 eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Z!qF0UDj GetConic eID, entity, curv, conic WFFpW{ r#K" d SetConic eID, entity, 1/Rpost, CCpost {X>U`0P Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost , MU9p* SQx:`{O '************************************************************************* vghn+P8 'Lens thickness (Position of posterior lens surface) iMOf];O) '************************************************************************* gc{5/U9H* G3t
4$3| parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'P~6_BW }sS1p6z ' Delete any z-shift(s) JZrUl^8E count = 0 AkRZUj\ While GetOperationCount(eID)>count bLyG3~P;0 GetOperation eID, count, op M;qV%
k If op.Type="ShiftZ" Then &M^FA=J\ DeleteOperation eID,count WWYG>C[ count=count-1 nzORG End If Z'z~40Bda count=count+1 $Uxg$p qO Wend J'y*>dW t~"DQqE 'Set new z-shift EM.rO/qcW op.Type = "ShiftZ" s
*1%I$=@ op.val1 = tlens wH[}@ w op.parent = parID $U/_8^6B0 AddOperation eID, op S~DY1e54GF Print "Set lens thickness = " & tlens ~j2=hkS
n;Etn!4M '************************************************************************* >jDx-H.N 'Lens index of refraction Y_<(~eN` '************************************************************************* =Z(#j5TGvH eID = FindMaterial( "Lens" ) XS/5y(W GetModelMaterial eID, mat CiGN?1| _Uz}z#jt mat.Nd = nlens BV
HO_ SetModelMaterial eID, mat Af"vSL Print "Set lens index of refraction = " & nlens kpN'H_ . $R<eXDW6: '************************************************************************* v{2Vg 'Pupil diameter #i GRi!$h '************************************************************************* XL7jUi_4:L eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) v+Q#O[ 8; s$?*Gi 'Adjust pupil diameter (trimming volume inner hole) wfrWpz=FO 2tqO%8`_ SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" %lU$;cY &j7l#Urq ' Adjust pupil location to just in front of the lens ~L'}!'
&. parID = FindFullName( "Geometry.Arizona Eye" ) dj76YK eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ZWJFd(6 count = 0 2O5yS While GetOperationCount(eID)>count o*u A+7n GetOperation eID, count, op prY9SQd If op.Type="ShiftZ" Then t%AW0#TZ DeleteOperation eID,count /vB%gqJvX count=count-1 lA<IcW End If ngJES`0d count=count+1 d0 tN73( Wend I
-obfyije op.Type = "ShiftZ" Bv |Z)G%RR op.val1 = taq-0.01 ]eq3cwR[| op.parent = parID F#^ .L|d4 AddOperation eID, op LV 94i ;.h5; `& Print "Set pupil diameter = " & pupilDiam yXw xq(32 .n`MPx' 'Update AZ Eye subassembly Description -K/' }I eID = FindFullName( "Geometry.Arizona Eye" ) F7 7[fp GetEntity eID, entity x9HA^Rj4- entity.Description = "Accommodation = " & A & "D" !`='K
+ SetEntity eID, entity R#bg{| E4[\lX$J Update qD#-q vn Print "DONE!" _wf"E(c3D 9ffRY,1@ End Sub MnsnW{VGX !U/:!e`N 如果屈光度是4,光瞳直径是4,则会输出如下数据: ,Ql3RO, DD'<zL[ Accommodation = 4 Diopters cuquA ~ Pupil Diameter = 4 mm ^B?koU l^ Set aqueous humor thickness = 2.81 cVn7jxf Set anterior lens radius = 10.4 and conic constant = -2.375869 W9V%Xc`LQ Set posterior lens radius = -4.424557 and conic constant = -3.081019 Ye!= Set lens thickness = 3.927 !HDk] Set lens index of refraction = 1.42672 =W ! m` Set pupil diameter = 4 ASy7")5 DONE! ^ I,1kl~i
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