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2022-02-25 09:52 |
Arizona眼睛模型
简介 s'qd%JxD *cz nokq6 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。 .(^KA{ p;zV4uSv 模型 b(+M/O>I =7wI/5iN 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。 <]xGd!x$ Table 1. AZ眼睛模型的定义 [attachment=111140] o8;>E>; ~VYZu=p 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. $OB 2ZS" N}Q%y(O^ 光源 ;NQ9A &$) t>"UenJt- 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。 "c` $U]M% N^z4I,GV( [attachment=111141] 图1. 光源和提示信息使用 f]Z%,'1^ :_V9Jwu 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 d"o5uo O?5uCh$H 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。 FFX-kS [attachment=111142] 图2. 字母F光源的设定方法光 S^(OjS uNSaw['0j [attachment=111143] 图3. 字母F在视网膜上位置点列图 .P(k |D& {2 l35K= 视网膜的散射 V,:^@ 7d n]:Xmi8p 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。 UtPFkase 9'+Eu)l: [attachment=111144] 图4. 视网膜朗伯散射设定 U|SF;T
. C'$w*^me 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。 hS&3D6Gt " E+V>V+ [attachment=111145] 图5. 视网膜重点采样规格设定 5"5!\Zo w3l2u1u 脚本 =`Ii?xo %d?.v_Hu0 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: 4P(muOS [attachment=111146] 图6. 用户对话框的创建与编辑 #C^)W/dP [attachment=111147] 图7. 用户对话框编辑器 1%Hc/N- d8D0 28d 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。 r{\c.\ 余下的脚本计算与屈光度有关的所有参数。 W
D 8 R|&jvG=| 分析 wO<.wPa` xs#g 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 |)~t^ [attachment=111148] 图7. 字母F在视网膜上颜色分析 PgOOFRwP {BV0Y.O 脚本代码 5<64 C}fE3 %M)LC>c
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. NJ]AxFG
1N\/61+aA Dim entity As T_ENTITY U]Y</>xGI
Dim op As T_OPERATION *G rYB6MT Dim mat As T_MODELMATERIAL $?P 5A E Dim A As Double ,X`w/ 2O Dim pupilDiam As Double !ZxK+Xqx[ Dim eID As Long >lPWji'4; Dim parID As Long tzIcR
#Z Dim count As Integer oRkh>yj' Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /EP
RgRX Dim tlens As Double, nlens As Double ;f?suawMv Dim curv As Double, conic As Double 8MQb5( ! Dim ok As Long L2\<iJA}c i,V,0{$ Sub Main J2ZV\8t 76oJCNY '用户输入对话框 W6c]a/ Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 X!xmto TextBox 220,21,40,21,.TextBox1 'default: 0 .9NYa |+0 Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 216=7O2F OKButton 40,91,90,21 {,+{,Ere CancelButton 190,91,90,21 UaCfXTG Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 X 0vcBHh TextBox 220,49,40,21,.TextBox2 'default: 4 6 2:FlW> End Dialog ?3
S{>+' Dim dlg As UserDialog OLS/3c
z ]\Z8MxFD ok = Dialog (dlg) jK-b#h.gL =h\unQ1T If ok=0 Then 'cancel button was pressed q0C%">>1# Print "Execution cancelled." b(_f{R7PY End *^oL$_Y End If Q}9!aB, jd`h)4 'Assign accommodation and pupil diameter & use defaults if field left empty -e4TqzRr If dlg.TextBox1 = "" Then 9Iu"DOxX% A = 0 'Default accommodation 5,R4:y ?cK Else X5pb9zRq A = CDbl(dlg.TextBox1) 5) q_Aro End If =&i#NSK + 70x0z2 If dlg.TextBox2 = "" Then VUi> ]v/e pupilDiam = 4 'Default pupil diameter eo*l^7 Else a]/KJn/B( pupilDiam = CDbl(dlg.TextBox2) s0O]vDTR,H End If Jmuyd\?,b q|{z9V< Print " " BCfmnE4% Print "Accommodation = " & A & " Diopters" n:[@#xs- Print "Pupil Diameter = " & pupilDiam & " mm" $cWt^B' _\.4ofK( ' Calculate new parameters with accommodation h/Yxm2 taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness 8y']kVg ~&aULY?)] Rant = 12.0 - 0.4*A 'Radius of anterior lens Aydpr_lp CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens
OqWm5(u&S ypgM&"eR Rpost = -5.224557 + 0.2*A 'Radius of posterior lens q3vv^~ CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens "F =NDF >F>VlRg tlens = 3.767 + 0.04*A 'Lens thickness bg!(B<!X i)$P1h nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction 182g6/, '?jsH+j+ 'Adjust parameters to account for accommodation ^TD%l8o6 UEx13!iFo '************************************************************************* t.+)g-X 'Aqueous thickness (Position of Lens) $%^](- '************************************************************************* =w* 8 eID = FindFullName( "Geometry.Arizona Eye.Lens" ) !Rc
% GetCustomElement eID, entity 0
*;i]owV p+8o'dl8= parID = FindFullName( "Geometry.Arizona Eye" ) r .'xqzF/ h\p!J-V ' Delete any shift(s) in z }SC&6B?G count = 0 soLW'8 While GetOperationCount(eID)>count Ab]tLz|Z GetOperation eID, count, op suzK)rJ9i If op.Type="ShiftZ" Then HUMy\u84H DeleteOperation eID,count z#Fel/L`O count=count-1 P z~jW):E End If pSb tm74 count=count+1 x|yJCs> Wend Yj'9|4%+| c9G%;U) 'Set new shift in (3K3)0fy op.Type = "ShiftZ" N,Z*d op.val1 = taq Z.&/,UU:4 op.parent = parID nw\C+1F AddOperation eID, op R:+'"dBge Print "Set aqueous humor thickness = " & taq-0.55 0zA;%oP eAo+w*D( '************************************************************************* Pro?xY$E) 'Radius and conic constant of anterior lens *RxJ8.G '************************************************************************* ~&<t++ g eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ?Wz2J3A.2t GetConic eID, entity, curv, conic [|ZFei)r xVw@pR; SetConic eID, entity, 1/Rant, CCant ?_FL
'G Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Pn^ `_ @I-,5F|r '************************************************************************* M 9-Q 'Radius and conic constant of posterior lens Yb^e7Eug '************************************************************************* #2s}s<Sc; eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) .Sn{a}XP4 GetConic eID, entity, curv, conic ^utOVi _]33Ht9 SetConic eID, entity, 1/Rpost, CCpost xhbN=L Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost nhdZC@~E0 ~h_
_Y> '************************************************************************* faDS!E' + 'Lens thickness (Position of posterior lens surface) T 5Zh2Q@ '************************************************************************* EYn?YiVFU L'r&'y[ parID = FindFullName( "Geometry.Arizona Eye.Lens" ) g=[OH o S= !6h ' Delete any z-shift(s) %SOXw8- count = 0 iphC\*F While GetOperationCount(eID)>count g3c<c S^l GetOperation eID, count, op LT<2 n.S
If op.Type="ShiftZ" Then ]y6{um8" DeleteOperation eID,count <zR{'7L/ count=count-1 L~-/'+ End If 9c[X[Qc count=count+1 Bkd$'7UT Wend uDie205 jhm/<= 'Set new z-shift \894Jqh op.Type = "ShiftZ" {iX# op.val1 = tlens 2L1y4nnbwo op.parent = parID ns%gb!FBJX AddOperation eID, op . 2$J-<O Print "Set lens thickness = " & tlens /^AH/,p o3dqsQE% '************************************************************************* Vt(Wy 'Lens index of refraction j{OA%G(I '************************************************************************* b'\Q/;oz> eID = FindMaterial( "Lens" ) jcJ 4? GetModelMaterial eID, mat D#L(ZlD4 M i& ;1!bg mat.Nd = nlens ^T!Zz"/: SetModelMaterial eID, mat =}#yi<Lt Print "Set lens index of refraction = " & nlens salC4z3 {ogBoDS '************************************************************************* GMJ4v S 'Pupil diameter @w8}]S '************************************************************************* 86OrJdD8 eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #+1|O;PB# c'i5,\ #X 'Adjust pupil diameter (trimming volume inner hole) RFL*
qd4 -}%J3j|R: SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" iT
:3e% Ob/)f)!! ' Adjust pupil location to just in front of the lens g8N"-j&@ parID = FindFullName( "Geometry.Arizona Eye" ) AOZ C D{ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 3_)I&RM count = 0 QcL@3QC While GetOperationCount(eID)>count RG{T\9]n GetOperation eID, count, op YbU8 xq If op.Type="ShiftZ" Then ;[::&qf DeleteOperation eID,count Mpojabsh count=count-1 !b+4[xky End If #"4ioTL2 count=count+1 _=~u\ $ Wend T&_&l;syA op.Type = "ShiftZ" ^[7Mp op.val1 = taq-0.01 +r3)\L{U op.parent = parID {!|4JquE_ AddOperation eID, op f256;3n Ma|4nLC} Print "Set pupil diameter = " & pupilDiam `[sFh%: Y/5M)AyJt 'Update AZ Eye subassembly Description A0Mjk eID = FindFullName( "Geometry.Arizona Eye" ) wtek5C^ GetEntity eID, entity !G3AD3 entity.Description = "Accommodation = " & A & "D" @q'kKVJs SetEntity eID, entity L(TM&
ps\- i\6CE| Update _p*9LsN$L Print "DONE!" v8ap"9b 1Z}5ykM3 End Sub S?0o[7(x* <IZt]P 如果屈光度是4,光瞳直径是4,则会输出如下数据: (zo7h rRq60A Accommodation = 4 Diopters xG/Q%A Pupil Diameter = 4 mm LDjtkD.r Set aqueous humor thickness = 2.81 n4kq=Z% Set anterior lens radius = 10.4 and conic constant = -2.375869 w~*@TG Set posterior lens radius = -4.424557 and conic constant = -3.081019 &'z_:W m Set lens thickness = 3.927 P4[kW}R Set lens index of refraction = 1.42672 ,0! 2x"Q= Set pupil diameter = 4 UGPDwgq\v DONE!
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