FRED运用:Arizona眼睛模型
简介 ;
KA~Z5x; 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。 %C0Dw\A*: *_e3 @g 模型 >usL*b0% @L`jk+Y0vF 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。 ,_P-$lB O<I-
Table 1. AZ眼睛模型的定义 [attachment=67931] fOHxtHM 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. bLL2 us.~G 光源 B:<VA= K@2),(z 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。 H+#FSdy# $j~RWfw- $xqa{L%B
[attachment=67932] 图1. 光源和提示信息使用 jCY%| 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。 z{543~Og59 xG 1nGO 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。 zqku e%^?- fJ\[*5eiS
[attachment=67933] 图2. 字母F光源的设定方法光 vI?, 47Hj+ 0_/[k*Re
[attachment=67934] 图3. 字母F在视网膜上位置点列图 yu|>t4#GT 视网膜的散射 3%6?g* eE Kf|I 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。 :3PH8TL
y7{?Ip4[ pYg/Zm
Jd
[attachment=67935] 图4. 视网膜朗伯散射设定 :m;p:l|W 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。 _aphkeqd ~Ei<Z`3}7" 5G#n"}T
[attachment=67936] 图5. 视网膜重点采样规格设定 4| f*eO 脚本 <aw[ XFg #Z #-Ht 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: #mT"gs UG^q9 :t
[attachment=67937] 图6. 用户对话框的创建与编辑 Iv *<La
[attachment=67938] 图7. 用户对话框编辑器 "Q<MS'a 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。 S/ *E,))m 余下的脚本计算与屈光度有关的所有参数。 n<,BmVQ &m3lXl 分析 wkq 66? NbobliC= 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 "%_+-C<L4 3Vwh|1?
[attachment=67939] 图7. 字母F在视网膜上颜色分析 (Z*!#}z` 脚本代码 #E?4E1bnB "Q0@/bYq Option Explicit 'Remove this to enable non-dimensioned variables to be used. h8P)%p `uFdwO'DD Dim entity As T_ENTITY pmM9,6P4@ Dim op As T_OPERATION >z03{=sAN Dim mat As T_MODELMATERIAL E./2jCwI(Y Dim A As Double |4JEU3\$ Dim pupilDiam As Double Q8NX)R Dim eID As Long
XX@ZQcN Dim parID As Long '%qr.T
% Dim count As Integer uH]OEz\H' Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double eRYK3W Dim tlens As Double, nlens As Double ok[i<zl;' Dim curv As Double, conic As Double 9Na$W:P
c Dim ok As Long +z( Lr=G NUZl`fu1Z4 Sub Main p ?!/+ 1^}+=~ '用户输入对话框 3Ul*QN{6 Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 =&]L00u. TextBox 220,21,40,21,.TextBox1 'default: 0 @- xjfC\d Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 %4H%?4 OKButton 40,91,90,21 !Ee:o"jG{ CancelButton 190,91,90,21 x4 yR8n( Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 \<' ?8ri# TextBox 220,49,40,21,.TextBox2 'default: 4 |N2#ItBbW End Dialog +nL[MSw Dim dlg As UserDialog uph(V ]`K2N ok = Dialog (dlg) 2 nCA<& 6t$8M[0-U If ok=0 Then 'cancel button was pressed XZ7Lk)IR Print "Execution cancelled." "[J^YKoF End WE?5ehEme End If tA;}h7/Lc~ +whDU2 " 'Assign accommodation and pupil diameter & use defaults if field left empty Tbq;h?D If dlg.TextBox1 = "" Then XTyxr A = 0 'Default accommodation KPF1cJ2N Else !a`&O-ye A = CDbl(dlg.TextBox1) ,F|f. 7; End If (HVGlw'` EwN}l If dlg.TextBox2 = "" Then iMlWM-wz>O pupilDiam = 4 'Default pupil diameter r&CiSMS* Else K-4PI+qQ\ pupilDiam = CDbl(dlg.TextBox2) t_^4`dW` End If 3w=J'(RU +%'(!A?*` Print " " XSRsGTCC= Print "Accommodation = " & A & " Diopters" aUp
g u" Print "Pupil Diameter = " & pupilDiam & " mm" A"]YM'. Psf#c:*_) ' Calculate new parameters with accommodation @C$]//; taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness >7|VR:U?B eFgA 8kY) Rant = 12.0 - 0.4*A 'Radius of anterior lens 3BI1fXT4=j CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens G\i9:7 ` Tk}]Gev Rpost = -5.224557 + 0.2*A 'Radius of posterior lens A^g(k5M* CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens 8LKiS &
21%zPm tlens = 3.767 + 0.04*A 'Lens thickness LV Ge]lD s;e\ pt nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction @{Q4^'K" /:
"1Z]@ 'Adjust parameters to account for accommodation <I?Zk80 IxU/?Zm '************************************************************************* zCZf%ATq 'Aqueous thickness (Position of Lens) dV_G1' '************************************************************************* I9Xuok!0>= eID = FindFullName( "Geometry.Arizona Eye.Lens" ) vsPu*[% GetCustomElement eID, entity }vuO$j 0J9x9j`&j parID = FindFullName( "Geometry.Arizona Eye" ) V
gWRW7Se @"A4$`Xi3 ' Delete any shift(s) in z /m1\ iM\ count = 0 Cdn J&N{ While GetOperationCount(eID)>count +7Gwg GetOperation eID, count, op Ud?Q%)X If op.Type="ShiftZ" Then .('SW\u- DeleteOperation eID,count Et$2Y-L. count=count-1 B\~}3!j End If -@'FW*b count=count+1 ^#pEPVkY Wend y[;>#j$ Q,g\ 'Set new shift in h p1Bi op.Type = "ShiftZ" z/-=%g >HA op.val1 = taq ?<!| op.parent = parID y29m/i: AddOperation eID, op Q &8-\ Print "Set aqueous humor thickness = " & taq-0.55 w)f#V s Jy)/%p~ '************************************************************************* sJZiI}Xc 'Radius and conic constant of anterior lens 6nn*]|7 '************************************************************************* K(4_a``05 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) %{W6PrY{ GetConic eID, entity, curv, conic "oyo#-5z 6ujWNf SetConic eID, entity, 1/Rant, CCant vM={V$D& Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant UQsN'r\tS hrk r'3lv '************************************************************************* E.h*g8bXe 'Radius and conic constant of posterior lens F ,kZU$ '************************************************************************* U{mYTN*:j$ eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) !
nx{
X GetConic eID, entity, curv, conic w0.
u\ tQVVhXQ7 SetConic eID, entity, 1/Rpost, CCpost P55fL-vo|} Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %d@z39-; *~`(RV '************************************************************************* :jf3HG 'Lens thickness (Position of posterior lens surface) Py<}S-: '************************************************************************* 6BlXLQ,8q
7GGUV parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 6]N.%Y[( _c07}aQ ], ' Delete any z-shift(s) TeQV?ZQ#} count = 0 \U0Q<ot/7 While GetOperationCount(eID)>count ~*7]r`6\@ GetOperation eID, count, op , gHDx If op.Type="ShiftZ" Then Om&Dw|xG8 DeleteOperation eID,count \V:^h[ad count=count-1 H,J8M{ End If XppOU count=count+1 qs6aB0ln Wend f$( e\++ ooGM$U 'Set new z-shift AA_%<zK op.Type = "ShiftZ" <@}9Bid!o op.val1 = tlens bt *k.=p op.parent = parID N`i/mP AddOperation eID, op nN;u,}e Print "Set lens thickness = " & tlens =N@t'fOr ~[: 2I '************************************************************************* yZ:qU({KhD 'Lens index of refraction CLSK'+l '************************************************************************* Ac6=(B eID = FindMaterial( "Lens" ) & kIFcd@ GetModelMaterial eID, mat 1M-pr 8:6s Rcv9mj]l mat.Nd = nlens $>gFf}#C SetModelMaterial eID, mat zDp 2g) Print "Set lens index of refraction = " & nlens 49P4b<1 QJNFA}*> '************************************************************************* B!yr!DWv 'Pupil diameter 9L9sqZUB '************************************************************************* l6B@qYLZ eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) q4q6c")zp m|# y
>4 'Adjust pupil diameter (trimming volume inner hole) ]_Xlq_[/r Vi}_{
Cy SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 0V]s:S "b[5]Y{
U ' Adjust pupil location to just in front of the lens 0c&+|>! parID = FindFullName( "Geometry.Arizona Eye" ) )Z$!PqRw@u eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) l0]
EX>"E count = 0 Q\)F;: | While GetOperationCount(eID)>count {*KEP GetOperation eID, count, op |}1dFp If op.Type="ShiftZ" Then E4!Fupkpf DeleteOperation eID,count Al'3? count=count-1 P2!C|SLK End If ~
1 pr~ count=count+1 u>$t' Wend m*;ERK op.Type = "ShiftZ" bcR_E5x$ op.val1 = taq-0.01 DJir { \F op.parent = parID OB7hlW AddOperation eID, op fnY.ao1-s[ BHw, 4#F1; Print "Set pupil diameter = " & pupilDiam eQ"E SaCh
7 ^ 'Update AZ Eye subassembly Description IB<d eID = FindFullName( "Geometry.Arizona Eye" ) M;NX:mX9 GetEntity eID, entity r/sNrB1U"y entity.Description = "Accommodation = " & A & "D" sGb{9.WK SetEntity eID, entity __@BUK{ q m,S{p<-h Update kLY^! Print "DONE!" C>~TI,5a3 OTp]Xe/ End Sub FqifriLN {T8Kk)L 如果屈光度是4,光瞳直径是4,则会输出如下数据: iUwzs&frd ':}\4j&{E Accommodation = 4 Diopters [2koe.?( Pupil Diameter = 4 mm fLVAKn Set aqueous humor thickness = 2.81 OH"XrCX7n Set anterior lens radius = 10.4 and conic constant = -2.375869 {U1m.30n Set posterior lens radius = -4.424557 and conic constant = -3.081019 w:l"\Tm Set lens thickness = 3.927 vj*%Q(E6Pt Set lens index of refraction = 1.42672 ,PZ ge Set pupil diameter = 4 yBRC*0+Vy DONE! rbQR,Nf2x _wOt39e&
(文章来源:讯技光电)
|