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2022-02-25 09:52 |
Arizona眼睛模型
简介 tKx~1- /,&<6c-Q@W 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。 hwBfdZ KD7dye 模型 Rmt~,cW!\ [KaAXv
.X 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。 <~'"<HwtK Table 1. AZ眼睛模型的定义 [attachment=111140] =I;ZMJR dx{bB%?Y\= 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. GmEJhr.3`= j2.|ln"! 光源 hl (hJfp BmMGx8P 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。 |5~#&v_ 9gEwh< [attachment=111141] 图1. 光源和提示信息使用 %wvdn #;qdY[v 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] PSpUd |[ k.ii6iO 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。 `nv~NLkl [attachment=111142] 图2. 字母F光源的设定方法光 ,nLy4T&" [-k [attachment=111143] 图3. 字母F在视网膜上位置点列图 ~f1%8z {V$|3m>:* 视网膜的散射 Tx=-Bb~; E+R1 !. 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。 8 \ +T8(m w/S%YW3* [attachment=111144] 图4. 视网膜朗伯散射设定 .4M.y:F I{9QeRI 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。 wQH<gJE/: k,E{C{^M [attachment=111145] 图5. 视网膜重点采样规格设定 \fyRsa)
bv9i*] 脚本 (Hz^)5(~ \y)rt ) 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: '4Ixqb+ [attachment=111146] 图6. 用户对话框的创建与编辑 '}JhzKNj [attachment=111147] 图7. 用户对话框编辑器 !N7s dY YpZ+n*&+ 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。 DV+xg3\(>1 余下的脚本计算与屈光度有关的所有参数。 $@Rxrx_@M YEs & 分析 g\(G\ tnu> 4(~L#}:r! 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 DiScFx|rE [attachment=111148] 图7. 字母F在视网膜上颜色分析 gsvuE V!ZC( 脚本代码 /-ch`u md ?(y*nD[a
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. c74.< @w
=J]]EoX/ Dim entity As T_ENTITY z8~NZ;A Dim op As T_OPERATION ./k/KSR Dim mat As T_MODELMATERIAL k\YG^I Dim A As Double yw[g!W Dim pupilDiam As Double t#/YN.@r Dim eID As Long |zNX=mAV Dim parID As Long c9'vDTE%~ Dim count As Integer :P\7iW Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double %~JJ. & Dim tlens As Double, nlens As Double +L|?~p`V Dim curv As Double, conic As Double WZejp}x Dim ok As Long Gg3,:A_ w n Fg~< $d Sub Main dA`IEQJL 88gM?G _X '用户输入对话框 -M~:lK]n Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 -.@r#d/ TextBox 220,21,40,21,.TextBox1 'default: 0 eRstD>r Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Uq,^Wy OKButton 40,91,90,21 }wjw:M CancelButton 190,91,90,21 N1S{suic Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 uR4z&y TextBox 220,49,40,21,.TextBox2 'default: 4 qIE9$7*X End Dialog +z\^t_"f Dim dlg As UserDialog Nk
8 B_{ 3{^9]7UC ok = Dialog (dlg) Mj?`j_X g i-$ZFzB If ok=0 Then 'cancel button was pressed |`,2ri*5A Print "Execution cancelled." :WS@=sZN End m6K}|j End If +wU@ynw D~fl JR 'Assign accommodation and pupil diameter & use defaults if field left empty ,RI Gc US If dlg.TextBox1 = "" Then UiP"Ixg6 A = 0 'Default accommodation Apag{Z]^B Else LTCb@L{^i A = CDbl(dlg.TextBox1) bMu+TgAT, End If Y%aCMP9j~9 @|m/djN5x If dlg.TextBox2 = "" Then #ut pupilDiam = 4 'Default pupil diameter 7~%?# Else 8oseYH pupilDiam = CDbl(dlg.TextBox2) rjAn@!|:+ End If z}9(x.I !cLo>,4 Print " " z`}qkbvi Print "Accommodation = " & A & " Diopters" o]_dJB Print "Pupil Diameter = " & pupilDiam & " mm" t%FwXaO# w\u=)3qyVV ' Calculate new parameters with accommodation Xp% v.M taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness o#gWbAG;]b %y[h5*y* Rant = 12.0 - 0.4*A 'Radius of anterior lens hJ? O],4J CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens XS{Qnx_# ~2N"#b&J Rpost = -5.224557 + 0.2*A 'Radius of posterior lens 1Z2HUzqh. CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens ({)+3]x fk>aqm7D! tlens = 3.767 + 0.04*A 'Lens thickness .},'~NM] 3m)0z{n nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction \fdv]f 1D7`YKI9h 'Adjust parameters to account for accommodation /NFj(+&g+ ,WYPU '************************************************************************* LEf^cM=> 'Aqueous thickness (Position of Lens) u@M,qo` '************************************************************************* 0<@KG8@hI; eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~<5!?6Yt GetCustomElement eID, entity yYYSeH ncdKj} parID = FindFullName( "Geometry.Arizona Eye" ) E_wCN&`[ xml7Uarc ' Delete any shift(s) in z .
iI count = 0 ]^7@}Ce_ While GetOperationCount(eID)>count s`8= 3]w GetOperation eID, count, op UHkMn If op.Type="ShiftZ" Then =R|HV;9 h DeleteOperation eID,count }C?'BRX count=count-1 Tv=mgH=b End If P>D)7V9Hh count=count+1 =BAr .m+" Wend AKfDXy o[w:1q7 'Set new shift in HM1Fz\Sf op.Type = "ShiftZ" ~jk|4`I?T op.val1 = taq p)-^;=<B3 op.parent = parID o#Dk&
cH AddOperation eID, op rJ4S%6w Print "Set aqueous humor thickness = " & taq-0.55 v{N`.~,^ *OsQ}onv '************************************************************************* Y\P8v 'Radius and conic constant of anterior lens AeM^73t '************************************************************************* |aS.a&vwR eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) H$t_Xw== GetConic eID, entity, curv, conic xm~`7~nFR 4E+e}\r:6 SetConic eID, entity, 1/Rant, CCant k]|~>9eY] Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant T3<4B!UB& 7xlkZF '************************************************************************* vn8aFA 'Radius and conic constant of posterior lens U< fGGCw '*************************************************************************
Pmx-8w eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) cqkV9f8Ro GetConic eID, entity, curv, conic pah'>dAL z&\a:fJ& SetConic eID, entity, 1/Rpost, CCpost 'JE`(xD Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /36:ms A {S)6;|ua' '************************************************************************* u&vf+6=9Dd 'Lens thickness (Position of posterior lens surface) =y*IfG9b '************************************************************************* CK@@HSm}l g:@#@1rB6 parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (5YM?QAd s ll\g ' Delete any z-shift(s) h;"4+uw count = 0 Sz`,X0a While GetOperationCount(eID)>count 4pF*"B GetOperation eID, count, op zC!t;*8a If op.Type="ShiftZ" Then <'oQ \eB DeleteOperation eID,count H*R"ntI?w count=count-1 V}CG:9; End If cV6D<,) count=count+1 #trK^( Wend !e<^?
r4 0s[Hkhls 'Set new z-shift
UI0VtR] op.Type = "ShiftZ" (w3YvG. op.val1 = tlens wwZ ,;\ op.parent = parID Yj49t_$b AddOperation eID, op M6jy\<a Print "Set lens thickness = " & tlens C&%_a~ bI1N@= '************************************************************************* tyFzSrfc 'Lens index of refraction XpHrt XD '************************************************************************* #;yZ eID = FindMaterial( "Lens" ) 1))8
A@, GetModelMaterial eID, mat gwMNYMI
}my`K mat.Nd = nlens 8nV+e~-w SetModelMaterial eID, mat oMa6(3T?E Print "Set lens index of refraction = " & nlens lymCH g) jYFfGfH '************************************************************************* Vc Z3
X4/ 'Pupil diameter $U~]=.n '************************************************************************* TvbE2Q;/UL eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) aW7^d'ZZ\ gM:".Ee 'Adjust pupil diameter (trimming volume inner hole) 46h<,na?, wmLs/:~ SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" #_p\Ie*rd UCj ld ' Adjust pupil location to just in front of the lens Iefn$ parID = FindFullName( "Geometry.Arizona Eye" ) Wne@<+mX eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) kxv1Hn"`{E count = 0 x%B/ While GetOperationCount(eID)>count b\2
ds, GetOperation eID, count, op c^W)07-X5y If op.Type="ShiftZ" Then j\M?~=*w DeleteOperation eID,count z2GY:<s count=count-1 G 3ptx!
D End If gcT%c|. count=count+1 s$j,9uRr Wend f@!.mDm] op.Type = "ShiftZ" P&Vv/D op.val1 = taq-0.01 (4nq>;$3 op.parent = parID Q$"D]!G AddOperation eID, op |sE'XT4ag T>W,'H Print "Set pupil diameter = " & pupilDiam S
f#
R0SA abVmkdP_s 'Update AZ Eye subassembly Description f/?P514h eID = FindFullName( "Geometry.Arizona Eye" ) H Pz+Dm GetEntity eID, entity w7L)'9 entity.Description = "Accommodation = " & A & "D" G3T]`Atf SetEntity eID, entity 9\(|
D# Mi_$">1-W Update
[$UI8tV Print "DONE!" qHsA1<wg C0Z=~Q% End Sub q)
KKvO JucY[`|JV 如果屈光度是4,光瞳直径是4,则会输出如下数据: mt.))#1 8z\xrY Accommodation = 4 Diopters E]r?{t`] Pupil Diameter = 4 mm 0"z9Q\{} Set aqueous humor thickness = 2.81 F!K>K z Set anterior lens radius = 10.4 and conic constant = -2.375869 |_U= z;Y Set posterior lens radius = -4.424557 and conic constant = -3.081019 u*9V&>o Set lens thickness = 3.927 'J|_2* Set lens index of refraction = 1.42672 .=;
; Set pupil diameter = 4 (/]
J3 DONE!
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