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2022-02-25 09:52 |
Arizona眼睛模型
简介 fqs p1m$ v+bjC 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。 Y8{1?LO o (NyOC 模型 <7]
Y\{+ !TZ/PqcE 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。 0$ac1;7 Table 1. AZ眼睛模型的定义 [attachment=111140] W2Z]?l;vQQ &U)s%D8e;d 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. c} ET#2, n<&R"89 光源 -" K:ve(K O t<%gj;^ 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 Qnx92 K05Y;URbd [attachment=111141] 图1. 光源和提示信息使用 Q&Ahr >F_Ne)}qTQ 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 DC7}Xly( K -1~K 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 tKGsrgoV [attachment=111142] 图2. 字母F光源的设定方法光 e-)1K iPpJ`i#@+ [attachment=111143] 图3. 字母F在视网膜上位置点列图 =8_TOvSJ4p `~TGVa`D 视网膜的散射 v 8a I;:_25WGC 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 6WM_V9Tidq # |[@Due [attachment=111144] 图4. 视网膜朗伯散射设定
`.WKU"To gRI|rDC)B 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 y36aoKH --)[>6)I [attachment=111145] 图5. 视网膜重点采样规格设定 %'O(Y{$Y. |JQKxvjT 脚本 ?7a[|-
kcUt!PL 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: h1)\.F4G [attachment=111146] 图6. 用户对话框的创建与编辑 OXV@LYP@ [attachment=111147] 图7. 用户对话框编辑器 !
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4 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。 t}l<#X5 余下的脚本计算与屈光度有关的所有参数。 SX;IUvVE5 !W^II>Y 分析 x%&V!L o!S_j^p[C 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 c7wgjQ[
[attachment=111148] 图7. 字母F在视网膜上颜色分析 U6PUt'Kk@ epm|pA* 脚本代码 3i~{x[Jc pl&GFf
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- Option Explicit 'Remove this to enable non-dimensioned variables to be used. 75i)$}_1B
1+iiiVbMH Dim entity As T_ENTITY /VkJ+%}+j Dim op As T_OPERATION iJeT+} Dim mat As T_MODELMATERIAL sOmYQ{R Dim A As Double 8+F2
!IM Dim pupilDiam As Double | 'G$}]H Dim eID As Long XWV ~6" Dim parID As Long $=R\3:j Dim count As Integer o\[nGf C& Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double IYN`q'%| Dim tlens As Double, nlens As Double n\U6oJN Dim curv As Double, conic As Double rD?o97 Dim ok As Long ccAEN <h[^&CY{ Sub Main ?zqXHv#x GvY8O|a '用户输入对话框 me" <+6 Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 m`aUz}Y>c TextBox 220,21,40,21,.TextBox1 'default: 0 E)bP}:4V Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 uc8>B&B% OKButton 40,91,90,21 `h#JDcT;a CancelButton 190,91,90,21 >EjBknl Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 up6LO7drW/ TextBox 220,49,40,21,.TextBox2 'default: 4 s!Vtwp9 End Dialog |kD?^Nx Dim dlg As UserDialog ww*F}}( anYZ"GR+ ok = Dialog (dlg) HAXx`r< e2v,#3Q\ If ok=0 Then 'cancel button was pressed ZN^Q!v Print "Execution cancelled." RIlPH~
End ~ nIZg5 End If IU/*YI%W +8"H%#~ 'Assign accommodation and pupil diameter & use defaults if field left empty {S c1!2q If dlg.TextBox1 = "" Then Sw~<W%! ? A = 0 'Default accommodation 3:RZ@~u= Else 3.Qwn. A = CDbl(dlg.TextBox1) @EvnV. End If qabM@+m[ tW +I? If dlg.TextBox2 = "" Then $xqphhBg pupilDiam = 4 'Default pupil diameter G[<iVt$y Else 8u4]@tJH pupilDiam = CDbl(dlg.TextBox2) LQ._?35r End If MLJ8m Vs(;al' Print " " y}|zH Print "Accommodation = " & A & " Diopters" ~lMsD~$sO Print "Pupil Diameter = " & pupilDiam & " mm" _ h#G- 2ZnTT{]_m ' Calculate new parameters with accommodation "dt3peH taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness Sx}h$E: nt7ui*k Rant = 12.0 - 0.4*A 'Radius of anterior lens ^I^k4iw4 CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens (jXgJ" m SU:Cm:$ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens <[*s%9)'9 CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens p?%G|Q
nWh?zf#{ tlens = 3.767 + 0.04*A 'Lens thickness hFKYRZtP.8 WW&0FugY_ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction [KJm&\evp ,]+6kf 5 'Adjust parameters to account for accommodation jtA
Yp3M-$ e3[N#ryt '************************************************************************* 2'++G[z 'Aqueous thickness (Position of Lens) _A(J^;? '************************************************************************* ks!
G \<I eID = FindFullName( "Geometry.Arizona Eye.Lens" ) y|X[NSA GetCustomElement eID, entity % 'P58 +Q{jV^IT9 parID = FindFullName( "Geometry.Arizona Eye" ) 1iz\8R:0 _3`{wzMA ' Delete any shift(s) in z r"xo 9&| count = 0 Fw=-gb_. While GetOperationCount(eID)>count Eh JYdO[e GetOperation eID, count, op KzhldMJ^zq If op.Type="ShiftZ" Then ^ c:(HUo# DeleteOperation eID,count 1w35H9\g count=count-1 i~4:]r22 End If Y40{v(Pi count=count+1 >2_J(vm> Wend o zv><e# d6_ CsqV 'Set new shift in a7Z PV1k op.Type = "ShiftZ" jn]{|QZ op.val1 = taq m]V5}-?al op.parent = parID m'Wz0b^BO AddOperation eID, op )wAqaG_d Print "Set aqueous humor thickness = " & taq-0.55 cU+/I>V s`&8tP '************************************************************************* Mk7#qiPo 'Radius and conic constant of anterior lens q[r|p"TGov '************************************************************************* WJ=^r@Sf eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 5gi`&t` GetConic eID, entity, curv, conic <V9L
AWeS 0,,x|g$TpT SetConic eID, entity, 1/Rant, CCant d!8`}L:=M Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 7\5;;23N4 \6*3&p '************************************************************************* fk9FR^u 'Radius and conic constant of posterior lens ZY=x$($f '************************************************************************* lQldW|S> eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) x# 0(CcKK GetConic eID, entity, curv, conic ^b'|`R+~} CpO!xj+ SetConic eID, entity, 1/Rpost, CCpost *s<FE F Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost YX,y7Uhn _yumUk-QW '************************************************************************* UuW" 'Lens thickness (Position of posterior lens surface) 2vT>hC?oHz '************************************************************************* q@H?ohIH a6fMx~ parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,ie84o
W& w-yZ ' Delete any z-shift(s) g!i\AMG? count = 0 @u#Tx% While GetOperationCount(eID)>count Pqi>,c<&mL GetOperation eID, count, op L@XhgQ If op.Type="ShiftZ" Then _m#M^<0n DeleteOperation eID,count 1
@tVfn} count=count-1 \|R P-8 End If 4#!NVI3t count=count+1 9=89)TrY Wend q3#07o_dV (g*2OS 'Set new z-shift PSNfh7g op.Type = "ShiftZ" q0,Diouq op.val1 = tlens tgKmCI op.parent = parID 43^%f-J5 AddOperation eID, op F_$eu-y Print "Set lens thickness = " & tlens -=I*{dzly iZyhj%# '************************************************************************* !inonR 'Lens index of refraction :D`ghXj '************************************************************************* R&PQU/t) eID = FindMaterial( "Lens" ) JL=MlZ GetModelMaterial eID, mat c%n[v3] FhVi|Va mat.Nd = nlens wK!4:]rhG SetModelMaterial eID, mat LzEs_B=9 Print "Set lens index of refraction = " & nlens wz3BtCx 3@f@4t@5V '************************************************************************* 2&S*> ( 'Pupil diameter F
0q#. '************************************************************************* x|&A^hQ eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) -Zh`h8gX ,Y6Me+5B 'Adjust pupil diameter (trimming volume inner hole) pn<M`,F~q }J$Q SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" D7T(B=S6 J39,x=8LL ' Adjust pupil location to just in front of the lens * _ {w0U) parID = FindFullName( "Geometry.Arizona Eye" ) VC,wQb1J/ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) C(qqGK{ count = 0 pHSq,XP- While GetOperationCount(eID)>count }%Dsy2:y GetOperation eID, count, op S4508l If op.Type="ShiftZ" Then jr29+> DeleteOperation eID,count dt%waM! count=count-1 ?]+{2&&$
End If :f<3`x' count=count+1 {L^b['h@ Wend Op%}.9 ed op.Type = "ShiftZ" ~Q}JC3f> op.val1 = taq-0.01 Q$r1beA op.parent = parID ! c,=%4Pb AddOperation eID, op s_xWvx8?4. (lBgWz Print "Set pupil diameter = " & pupilDiam Exd$v"s
Y 3}V`]B#a 'Update AZ Eye subassembly Description /<,LM8n eID = FindFullName( "Geometry.Arizona Eye" ) x@/ N9* GetEntity eID, entity Q[+&n* entity.Description = "Accommodation = " & A & "D" hqOy*!8'@ SetEntity eID, entity .4P5tIn\ ^|-*amh Update @y?<Kv}s Print "DONE!" ,w&8 &wj c@H:?s!0R End Sub #~<cp)!3 e%.Xya#\ 如果屈光度是4,光瞳直径是4,则会输出如下数据: F/GfEMSE l,5<g-r
V Accommodation = 4 Diopters wi]ya\(*yl Pupil Diameter = 4 mm 3{OY& Set aqueous humor thickness = 2.81 )*<=: Set anterior lens radius = 10.4 and conic constant = -2.375869 k/[*Wz$W Set posterior lens radius = -4.424557 and conic constant = -3.081019 baJ(Iy$XT Set lens thickness = 3.927 r,F~Vwa} Set lens index of refraction = 1.42672 1haNca_6, Set pupil diameter = 4 mqxgrb7 DONE!
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