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2016-02-24 12:53 |
FRED运用:Arizona眼睛模型
简介 S,udpQ7 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。 GT80k]e. VC_F
Cz 模型 k {vd1,HZ wDSwcNS 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。 ]&B/rSC 9i
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Table 1. AZ眼睛模型的定义 [attachment=67931] )~S`[jV5 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. $ %|b6Gr/& $P)-o?eer 光源 XMykUr e| W5e>Z&& 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 H3pZfdh?w 2P${5WT pIug$Ke_%
[attachment=67932] 图1. 光源和提示信息使用
/J Y6S 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 7/fJQM [3ggJcUgW> 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 j|qdf3^f <g\:By^
[attachment=67933] 图2. 字母F光源的设定方法光 EP<{3fy m*h O@M
[attachment=67934] 图3. 字母F在视网膜上位置点列图 LaZ
@4/z! 视网膜的散射 |Q@( <'8= Tc>g+eS 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 G(o6/ 0r[a$p>` 0"N4WH O
[attachment=67935] 图4. 视网膜朗伯散射设定 cG 3tn&AXi 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。 }5z!FXB F9(jx#J~t ^5>W`vwp
[attachment=67936] 图5. 视网膜重点采样规格设定 3j[<nBsn. 脚本 iCGHcN^3 Lm.N
{NV' 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: `#r/L@QI &uV|Ie8@q
[attachment=67937] 图6. 用户对话框的创建与编辑 9"/=D9o9
[attachment=67938] 图7. 用户对话框编辑器 Qw_>
l}k/ 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。 .<YfnW5/K 余下的脚本计算与屈光度有关的所有参数。 hY *^rY' :xO43z 分析 `r}a:w- .vIRz-S 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 vS:=%@c>ta <]#_&Na
[attachment=67939] 图7. 字母F在视网膜上颜色分析 4(Y-TFaf 脚本代码 ycEp,V;[Z yFDt%&*n^ Option Explicit 'Remove this to enable non-dimensioned variables to be used. ]n'.}"8Kn 5-'Z.[ImB? Dim entity As T_ENTITY 9I#a{%A: Dim op As T_OPERATION ]C|xo.=?] Dim mat As T_MODELMATERIAL Lm0q/d2|\X Dim A As Double qjf4G[]! Dim pupilDiam As Double X)c0y3hk Dim eID As Long b"w2 2% Dim parID As Long :g-vy9vb Dim count As Integer e;"%h%' Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double \9sJ`,T? Dim tlens As Double, nlens As Double *Ct
^jU7 Dim curv As Double, conic As Double Q(Pc Dim ok As Long A9Pq}3U 3cNr~`7 Sub Main JiXN"s^mcb
[Z1,~(3 '用户输入对话框 iRv\:.aQ. Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 v|jwz.jM TextBox 220,21,40,21,.TextBox1 'default: 0 u2U+uD@yA Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 I=YZ!* f/` OKButton 40,91,90,21 8p/&_<mnW CancelButton 190,91,90,21 i^4i]+ Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 '(3|hh)Tl TextBox 220,49,40,21,.TextBox2 'default: 4 4]%MrSjS End Dialog fCv.$5 Dim dlg As UserDialog sE^=]N 6Q*zZ]kg ok = Dialog (dlg) G?:5L0g lXnv(3j3*s If ok=0 Then 'cancel button was pressed ag!q:6& Print "Execution cancelled." |~Vq"6` End f4|ir3oy End If Bv6~!p q~xs4?n1U 'Assign accommodation and pupil diameter & use defaults if field left empty yoBR'$-= If dlg.TextBox1 = "" Then VlxHZ A = 0 'Default accommodation <sjz_::V8R Else ;4`%?6% A = CDbl(dlg.TextBox1) bHzH0v]: End If Wr4Ob*2iD &>}f\ch/ If dlg.TextBox2 = "" Then IBh?vh pupilDiam = 4 'Default pupil diameter ksAu=X: Else ]; B`'Ia pupilDiam = CDbl(dlg.TextBox2) #[~f 6s9D End If j[fY.>yt& ]Lm?3$u$ Print " " %
+M,FgW Print "Accommodation = " & A & " Diopters" :8lqo%5 Print "Pupil Diameter = " & pupilDiam & " mm" ;7mE%1X =UZQ` { ' Calculate new parameters with accommodation ]%h|ox0 taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness Q\2~^w1V D<bHRtP Rant = 12.0 - 0.4*A 'Radius of anterior lens e:n3@T,R CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens @dvb%A&Pur )zo:Bo
.< Rpost = -5.224557 + 0.2*A 'Radius of posterior lens cN]g^ CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens M#SGZ~=1r oJ0ZZu?{D tlens = 3.767 + 0.04*A 'Lens thickness m Wh 5oOFl nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction -1]8f |6Qn/N$+f 'Adjust parameters to account for accommodation a]?o"{{+ $HFimU,V=0 '************************************************************************* XchVsA 'Aqueous thickness (Position of Lens) "pQ)5/e '*************************************************************************
g6;a2 eID = FindFullName( "Geometry.Arizona Eye.Lens" ) `4t*H>:y GetCustomElement eID, entity OUtMel_ RjGJfN{ parID = FindFullName( "Geometry.Arizona Eye" ) tS3{y*yi <io;d$=} ' Delete any shift(s) in z [xl+/F7 count = 0 |OO2>(Fj While GetOperationCount(eID)>count h@D!/PS GetOperation eID, count, op zd{\XW If op.Type="ShiftZ" Then 4+B
OS ~ DeleteOperation eID,count HH7Bg0=( count=count-1 42.y.LtZ End If HD8*>p. count=count+1 Q=F4ZrNqD Wend 4So
,m0v =(p]L 'Set new shift in n4DKLAl op.Type = "ShiftZ" jmn<gJ2Of op.val1 = taq o=I.i>c op.parent = parID !2]'S=Y AddOperation eID, op n_P2l<F~/x Print "Set aqueous humor thickness = " & taq-0.55 Cg];UB}k ,qK3
3Bn '************************************************************************* =g$>]AE 'Radius and conic constant of anterior lens t@3y9U$ '************************************************************************* :lp
V eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) '2xfU GetConic eID, entity, curv, conic Kb*X2#;* {4HcecT SetConic eID, entity, 1/Rant, CCant ,];QzENw Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?m:,hI ~cb7]^#u1l '************************************************************************* U6LENY+Ja 'Radius and conic constant of posterior lens 0z`-fQfK '************************************************************************* NrWgaPO)i eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )
i5Dq'wp GetConic eID, entity, curv, conic 9"b =W@ ko`.nSZ-k SetConic eID, entity, 1/Rpost, CCpost mD go@f Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [IPXU9&Q ,*d<hBGbh '************************************************************************* Xx
e07J~ 'Lens thickness (Position of posterior lens surface) R9)"%SO<y '************************************************************************* i
3i !6l}s$1i| parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z:Y_{YAD ]r(s02 ' Delete any z-shift(s) @Avve8S count = 0 +$
0wBU While GetOperationCount(eID)>count ]T1\gv1~ GetOperation eID, count, op o ^Ro 54i If op.Type="ShiftZ" Then %v,a3^Qu DeleteOperation eID,count wlw`%z-B2 count=count-1 V~"-\@ End If USJk
* count=count+1 R 9b0D>Lxt Wend ^H~g7&f9?N JNxrs~} 'Set new z-shift =.ReM_. op.Type = "ShiftZ" pMLTXqL op.val1 = tlens '0
J*9 op.parent = parID a?8boN( AddOperation eID, op ANq3r( Print "Set lens thickness = " & tlens ['Y"6[1
G:i>MJbxT '************************************************************************* /#g
P#Z% 'Lens index of refraction MWJ} '************************************************************************* (e_ l1O? eID = FindMaterial( "Lens" ) uXo? GetModelMaterial eID, mat 't3&,:Y -xL^UcG0 mat.Nd = nlens 7,"y!\ SetModelMaterial eID, mat A#8J6xcSrL Print "Set lens index of refraction = " & nlens |}isSCt i 2l/y,UX '************************************************************************* \"1%>O* 'Pupil diameter T$*#q('1"} '************************************************************************* @!p0<&R@x eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) \%|%C U%rq(`;
'Adjust pupil diameter (trimming volume inner hole) DLD 5> }j;G`mV2 SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" j] J-#J mKuY=#R P ' Adjust pupil location to just in front of the lens 2U@:.S'K parID = FindFullName( "Geometry.Arizona Eye" ) UT_kw}1o eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) __|Y59J% count = 0 dheobD While GetOperationCount(eID)>count iCtS<"@Yx GetOperation eID, count, op rr]-$]Q If op.Type="ShiftZ" Then _f"KB=A_x DeleteOperation eID,count d9q`IZqee count=count-1 *=X61`0 End If sQBKzvFO3 count=count+1 ;e0-FF+ Wend D-LQQ{!D5 op.Type = "ShiftZ" `APeS=<
& op.val1 = taq-0.01 QzS=oiL op.parent = parID
z-_$P)[c AddOperation eID, op <RuLIu "xAIK Print "Set pupil diameter = " & pupilDiam jM:|%o &[P(}??Y\ 'Update AZ Eye subassembly Description Egmp8:nZl@ eID = FindFullName( "Geometry.Arizona Eye" ) +h@ZnFp3 GetEntity eID, entity /Xl(>^|& entity.Description = "Accommodation = " & A & "D" Q'rgh+6 SetEntity eID, entity 8(g}/%1mt3 sGG
q~7 Update mC}
b>\ Print "DONE!" )zkr[;j~` $bl<mG%#9 End Sub Mh]4K"cs Q7-'5s 如果屈光度是4,光瞳直径是4,则会输出如下数据: $kc cM&B T&'LQZM8 Accommodation = 4 Diopters U#:N/ts*( Pupil Diameter = 4 mm yVWt%o/ Set aqueous humor thickness = 2.81 2TgS
) Set anterior lens radius = 10.4 and conic constant = -2.375869 80K"u[ Set posterior lens radius = -4.424557 and conic constant = -3.081019 $}B&u ) Set lens thickness = 3.927 SB,#y>Zv? Set lens index of refraction = 1.42672 \%_sL#? Set pupil diameter = 4 kn+@)3W:* DONE! mYbu1542'n VFq7nV/O
(文章来源:讯技光电)
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