Arizona眼睛模型
简介 jw#'f%* hGD7/qTN 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。 u`K+0^)T` $ShL^g@ 模型 3(6i6 vV {EZ
; 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。 t'0r4&\ Table 1. AZ眼睛模型的定义 [attachment=111140] \wO)w@" }"Y]GH4Y 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. F!j@b!J8 ~"brfjd| 光源 HIi"zo=V b
3D:w{l 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。 <}N0y*m A
CJmy2 [attachment=111141] 图1. 光源和提示信息使用 QBY7ZT05Gt 18V*Cu 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。 )v8;\1`s: p !U#53 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。 qV8;;&8r [attachment=111142] 图2. 字母F光源的设定方法光 e+4p__TmZ @5Ril9J[b [attachment=111143] 图3. 字母F在视网膜上位置点列图 Zdj~B1 #qm<4]91 视网膜的散射 Yca9G?^\v ,LWM}L 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。 Vg6?a q.~.1
'`! [attachment=111144] 图4. 视网膜朗伯散射设定 8p>%}LX/ FhAuTZk 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。 X#1So .}c !);}zW! [attachment=111145] 图5. 视网膜重点采样规格设定 hFj.d]S Y5cUOfYT 脚本 u#la+/
noh3mi 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: : gv[X [attachment=111146] 图6. 用户对话框的创建与编辑
KW^s~j [attachment=111147] 图7. 用户对话框编辑器 q;tsA"l /2Y
Nu*v 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。 N, ;'oL+ 余下的脚本计算与屈光度有关的所有参数。 "p2 $R*ie *G>V`||RW 分析 p0`Wci 52wq<[#tK 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ?VS {,"X [attachment=111148] 图7. 字母F在视网膜上颜色分析 wToz{!n _6^ vxlF 脚本代码 n*@^c$&P 4UC/pGZY
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. =n9adq
ZCbxL.fFz Dim entity As T_ENTITY E'JVf%) Dim op As T_OPERATION 7+#^:;19` Dim mat As T_MODELMATERIAL IP&En8W+ Dim A As Double CHN!o9f Dim pupilDiam As Double N;Hrc6nin^ Dim eID As Long 4h:Oo Dim parID As Long }_@cqx:n^ Dim count As Integer REQ2pfk0 Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ,'={/)c< Dim tlens As Double, nlens As Double ~W%A8`9 Dim curv As Double, conic As Double m\"M`o
B Dim ok As Long gC<\1AIu D:8-f3 Sub Main p^5B_r: 7{8!IcR # '用户输入对话框 @<W"$_r- Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 dH#S69> TextBox 220,21,40,21,.TextBox1 'default: 0 "&Q-'L!M'/ Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 s3/->1#i OKButton 40,91,90,21 mrE^D| CancelButton 190,91,90,21 H Y.,f_m Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 onG,N1`+ TextBox 220,49,40,21,.TextBox2 'default: 4 :NA cad End Dialog {~b]6}O Dim dlg As UserDialog q+WO nTS FspI[gUN, ok = Dialog (dlg) )amdRc 3`SLMPI If ok=0 Then 'cancel button was pressed A9p$5jt7 Print "Execution cancelled." 1PjSa4 End #s(B,`?N End If P,_GTs3/G W\N-~9UA 'Assign accommodation and pupil diameter & use defaults if field left empty 8kH'ai If dlg.TextBox1 = "" Then ?u'JhZ A = 0 'Default accommodation ,XI,B\eNk Else .fUqsq A = CDbl(dlg.TextBox1) K )KE0/n End If \>23_d0 x>&1;g2r If dlg.TextBox2 = "" Then i*9eU*i|H pupilDiam = 4 'Default pupil diameter a!Z,~ V8 Else wV W+~DJ pupilDiam = CDbl(dlg.TextBox2) ;vQ7[Pv.j End If B%^B_s VskyRxfdW3 Print " " &nZ=w#_ Print "Accommodation = " & A & " Diopters" 2ZNTg@o Print "Pupil Diameter = " & pupilDiam & " mm" ~Jp\'P7* .F'Fk=N ' Calculate new parameters with accommodation n KDX=73 taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness bveNd0hN 1,,o_e\nn3 Rant = 12.0 - 0.4*A 'Radius of anterior lens QIBv}hgcy CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens 7{."Y@ .;/@k%> Rpost = -5.224557 + 0.2*A 'Radius of posterior lens yY`<t CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens hh
<=D.u 7! <cU tlens = 3.767 + 0.04*A 'Lens thickness <3Co/ .VQd vRRi"bo nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction 6>Lr 9t7_7{Q+; 'Adjust parameters to account for accommodation VSms hld -;Cl0O% '************************************************************************* )q&uvfQ1( 'Aqueous thickness (Position of Lens) 'u_'y '************************************************************************* ,)S|%tDW eID = FindFullName( "Geometry.Arizona Eye.Lens" ) DH)@8)C GetCustomElement eID, entity oKA8)~Xqou SZK~<@q5 parID = FindFullName( "Geometry.Arizona Eye" ) &wK%p/? C1r]kF ' Delete any shift(s) in z ,t*#o&+ count = 0 @e$zEj5 While GetOperationCount(eID)>count lwQI
9U[O2 GetOperation eID, count, op $N+a4 If op.Type="ShiftZ" Then LPO3B W DeleteOperation eID,count H.|FEV@ count=count-1 (!W:-|[K\ End If _4x X}Z; count=count+1 |1T2<ZT Wend %I&Hx<Hj 7=Ew[MOmM 'Set new shift in `<b 3e(A op.Type = "ShiftZ" h+t{z"Ic= op.val1 = taq !yG{`#NZZ op.parent = parID 3xp%o5K AddOperation eID, op D!TS/J1S;u Print "Set aqueous humor thickness = " & taq-0.55 `:-{8Vo7 wrac\. '************************************************************************* ?9OiF-:n 'Radius and conic constant of anterior lens hi`\3B '************************************************************************* -P(q<T2MV' eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) T%
Kj >- GetConic eID, entity, curv, conic v?-pAA)ht cqRIi~` SetConic eID, entity, 1/Rant, CCant j:O=9 Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant }yK_2zak5i -9.S?N'T>; '************************************************************************* !@W1d|{lu 'Radius and conic constant of posterior lens &r/a\t,8n '************************************************************************* Beiz*2-}a eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) {S'xZ._= GetConic eID, entity, curv, conic A_CEpG] t
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y"N# SetConic eID, entity, 1/Rpost, CCpost ZiSy&r:( Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;rV0 B&O931E7 '************************************************************************* ]lXTIej`dy 'Lens thickness (Position of posterior lens surface) *&% kkbA '************************************************************************* N6Vn/7I5% ~+q$TV parID = FindFullName( "Geometry.Arizona Eye.Lens" ) TsfOod esLPJx ' Delete any z-shift(s) O-U_Zx0zd count = 0 \3O#H While GetOperationCount(eID)>count \2L%%M GetOperation eID, count, op .px*.e s If op.Type="ShiftZ" Then m!$"-nh9 DeleteOperation eID,count s@jzu count=count-1 OzA"i y End If ,fT5I6l count=count+1 H9xxId?3u Wend `Ft.Rwj2:m cPPE8}PVH 'Set new z-shift q/ 6d^& op.Type = "ShiftZ" <DvpqlT op.val1 = tlens ;Tvy)*{ op.parent = parID =L
7scv%i AddOperation eID, op 8]YFlW9 Print "Set lens thickness = " & tlens "6gu6f H8`K?SXU '************************************************************************* V+nqQ~pJ& 'Lens index of refraction 0"ZB|^c= '************************************************************************* V2u^sy eID = FindMaterial( "Lens" ) :eo2t>zF-< GetModelMaterial eID, mat Hd
U1gV> eg3zpgZ mat.Nd = nlens k =ru)
_$2 SetModelMaterial eID, mat QukLsl]U Print "Set lens index of refraction = " & nlens so9h6K{qcp S"!nM]2L '************************************************************************* ([qw#!;w; 'Pupil diameter B;SYO>.W '************************************************************************* Ja4O*C< eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) JrQd7 %i]q} M 'Adjust pupil diameter (trimming volume inner hole) _Su?
VxU $Dxz21|P7 SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" pfe9n[ JY(_}AAu ' Adjust pupil location to just in front of the lens Zoh2m`6 parID = FindFullName( "Geometry.Arizona Eye" ) xm6=l".%z eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) J)6RXt*! count = 0 +`r;3kH .. While GetOperationCount(eID)>count Egi<m GetOperation eID, count, op )|~pocXt< If op.Type="ShiftZ" Then razVO]]E DeleteOperation eID,count wcspqC" _ count=count-1 w`bojM@e1 End If )V*Z|,#no count=count+1 fLa 7d?4 Wend ;[R{oW
Nw op.Type = "ShiftZ" r{pTMcDS op.val1 = taq-0.01 I8d#AVF2 op.parent = parID 9KN75<n AddOperation eID, op ex
@e-< }oIA*:5 Print "Set pupil diameter = " & pupilDiam ryy".'v w^s|YF=c 'Update AZ Eye subassembly Description i(Cd#1< eID = FindFullName( "Geometry.Arizona Eye" ) 6D_3Hwrs GetEntity eID, entity z4D[>2* entity.Description = "Accommodation = " & A & "D" g)u
~GA*= SetEntity eID, entity \{ r%.G /XEUJC4 Update OGw =e{ Print "DONE!" ftw\oGrS 2%y}El^+_ End Sub YDE;mIW .E-)R 如果屈光度是4,光瞳直径是4,则会输出如下数据: Q&}`( ]k cY
^>` Accommodation = 4 Diopters Q|q.~x<RQ Pupil Diameter = 4 mm 7%)
F] Set aqueous humor thickness = 2.81 J+r\EN^9 Set anterior lens radius = 10.4 and conic constant = -2.375869 6nV]Ec~3[ Set posterior lens radius = -4.424557 and conic constant = -3.081019 >T[1=;o] Set lens thickness = 3.927 DF|(CQs9 Set lens index of refraction = 1.42672 |_@ '_ Set pupil diameter = 4 Oz<{B]pEul DONE!
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