| infotek |
2022-02-25 09:52 |
Arizona眼睛模型
简介 [>E0(S] Rjf| 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。 l< Y x u8*0r{kOH 模型 s=:n<`Z2 yAOC<d9 E 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。 V4 7Fp Table 1. AZ眼睛模型的定义 [attachment=111140] /bWV`* <FP-]R) 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. Po5}Vh ,Gfnf%H\8> 光源 x{rt\OT X*T9`]l6 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。 *;Vq0a! +=R:n^r^, [attachment=111141] 图1. 光源和提示信息使用 aD4ln]sFxG -Je+7#P1 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。 ]n+:lsiV zMa`olTZ 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。 o}T]f(>} [attachment=111142] 图2. 字母F光源的设定方法光 QwhPN'U wdg[pt
/> [attachment=111143] 图3. 字母F在视网膜上位置点列图 L@/+u+j0 >,DR{A2hSB 视网膜的散射 &c]x;#-y <,m}TTq 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。 e"vEh G
5)?! [attachment=111144] 图4. 视网膜朗伯散射设定 H Q2-20 4ngiad6bR 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。 #8PjYB t*COzE [attachment=111145] 图5. 视网膜重点采样规格设定 RKe19l_V ?}W:DGudZ 脚本 .8"o&%$`V )T>a|. 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: bc+'n [attachment=111146] 图6. 用户对话框的创建与编辑 4o%hH [attachment=111147] 图7. 用户对话框编辑器 A3Su&0uaB B$\5=[U 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。 !l'Zar 余下的脚本计算与屈光度有关的所有参数。 , 7}Ri 7B'0(70 分析 j#-74{Y$
J 9Vp$A$7M 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 o:?IT/> [attachment=111148] 图7. 字母F在视网膜上颜色分析 ddw!FH2W
( Q[}mH: w 脚本代码 >9|Q,/b0 mk[n3oE1
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. V482V#BP
er 97&5 Dim entity As T_ENTITY n|(Y?`( Dim op As T_OPERATION 2^|*M@3r Dim mat As T_MODELMATERIAL A0'Yfuie Dim A As Double k(T/ydrw Dim pupilDiam As Double ^f4qs Dim eID As Long " I:j a7 Dim parID As Long r>
NgJf, Dim count As Integer HSTtDTo Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &ed.%: Dim tlens As Double, nlens As Double oqG
0 @@ Dim curv As Double, conic As Double J H6\;G6 Dim ok As Long $[IuEdc/ IuRKj8J)o Sub Main W4Zi?@L>' ^G5_d"Gr '用户输入对话框 ;0ake%v] Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ."9v1kW TextBox 220,21,40,21,.TextBox1 'default: 0 N8:vn0ww Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 y%43w4 OKButton 40,91,90,21 SC'fT! CancelButton 190,91,90,21 [7$.)}Q- Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 >YD?
pDPb/ TextBox 220,49,40,21,.TextBox2 'default: 4 tM~R?9OaJ End Dialog qRTy}FU1 Dim dlg As UserDialog |',MgA Uh*V>HA# ok = Dialog (dlg) nd-y`@z $l Y If ok=0 Then 'cancel button was pressed o4tQ9X=} Print "Execution cancelled." $dq
R]' End 5r@x$* >e End If u PjJ>v YMC*<wXN 'Assign accommodation and pupil diameter & use defaults if field left empty Fj|C+;Q. If dlg.TextBox1 = "" Then 7)z^*;x A = 0 'Default accommodation uTngDk Else s-Bpd#G>/ A = CDbl(dlg.TextBox1) LY/K,6^a End If Q!MS_
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R;Xj3]v If dlg.TextBox2 = "" Then nCJ)=P.d pupilDiam = 4 'Default pupil diameter ,{7Z OzA Else V{ECDgP pupilDiam = CDbl(dlg.TextBox2) ~gmj/PQ0 End If iq=<LOx o[0Cv* Print " " Fd9ypZs Print "Accommodation = " & A & " Diopters" Y0
Ta&TYZ0 Print "Pupil Diameter = " & pupilDiam & " mm" WM~@/J Fep#Pw1 ' Calculate new parameters with accommodation o{lR_ taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness SVo:%mX _|`S9Nms Rant = 12.0 - 0.4*A 'Radius of anterior lens ;5?$q CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens +.:- : .sgP3Ah Rpost = -5.224557 + 0.2*A 'Radius of posterior lens
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m CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens txw:m*(% ]^$3S tlens = 3.767 + 0.04*A 'Lens thickness tY~EB.% >S,yqKp37~ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction t32
FNg &82Za% 'Adjust parameters to account for accommodation Gk
g)\ 3 U@Y0 z.Y '************************************************************************* $OldHe[p 'Aqueous thickness (Position of Lens) >/9f>d?w^ '************************************************************************* v=R=K eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Q,S~+bD(z GetCustomElement eID, entity ozy~`$;c Ko|nF-r_ parID = FindFullName( "Geometry.Arizona Eye" ) wsYvbI! ~7IXJeon ' Delete any shift(s) in z Q$^oIFb count = 0 e3oHe1"hP While GetOperationCount(eID)>count yY_Zq\ GetOperation eID, count, op P>j^w#$n If op.Type="ShiftZ" Then a<*q+a(*W DeleteOperation eID,count @(<C { count=count-1 c@>Tzk%?" End If F !g>fIg count=count+1 dj>zy Wend
T)?:q MH7 n@.t 'Set new shift in wVX]"o op.Type = "ShiftZ" <[Oe.0SGu op.val1 = taq &c>%E%!" op.parent = parID G<:_O-cPSv AddOperation eID, op ]-]K4*{ Print "Set aqueous humor thickness = " & taq-0.55 H\H4AAP5F$ yq]= +X>( '************************************************************************* jMr [UZ 'Radius and conic constant of anterior lens *oZ]k`-!8 '*************************************************************************
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eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) '-c
*S]: r GetConic eID, entity, curv, conic o{MF'B# [QwEidX| SetConic eID, entity, 1/Rant, CCant "%]<Co<S Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant v,]-;V~< a8nqzuI '************************************************************************* 5argw+2s4$ 'Radius and conic constant of posterior lens 5,dKha '************************************************************************* GYH{_Fq eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) fSc)PqLP GetConic eID, entity, curv, conic b$FK}D5 ~P!\;S SetConic eID, entity, 1/Rpost, CCpost =`<9N% Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost lidVe]> !r^fX=X>' '************************************************************************* r c++c,= 'Lens thickness (Position of posterior lens surface) D]tI's1 '************************************************************************* JX!z,X?r4 ak1?MKV. parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *'&]DJj R|D%1@i] ' Delete any z-shift(s) qh9d.Q+n count = 0 F-R5Ib-F*A While GetOperationCount(eID)>count dbga >j GetOperation eID, count, op gpT~3c;l= If op.Type="ShiftZ" Then eYtP396C| DeleteOperation eID,count Z-%zR'-?* count=count-1 JsP<etX End If (}B3df count=count+1 [/=Z2mtA Wend -XASS% /aV;EkyO, 'Set new z-shift ~cv322N op.Type = "ShiftZ" mY=Q#nG op.val1 = tlens 8yCt(ms op.parent = parID _w}l, AddOperation eID, op B)/L[ )S Print "Set lens thickness = " & tlens qt{lZ_$ s,CN<`/>x '*************************************************************************
^t}1$H 'Lens index of refraction 3s\}|LqX# '************************************************************************* t1`.M$ eID = FindMaterial( "Lens" ) "%I<yUP]U GetModelMaterial eID, mat @ /.w% w%1-_;.aU6 mat.Nd = nlens @#r6->%W SetModelMaterial eID, mat S:lie*Aux* Print "Set lens index of refraction = " & nlens &M>o -xXdT$Xd '************************************************************************* 3d`u!i?/ 'Pupil diameter u']}Z%A9` '************************************************************************* m)l'i!Y eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Np"~1z.(b I:6H65(& 'Adjust pupil diameter (trimming volume inner hole) 7!F -.kG D wfw|h SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" #=V\WQb (nu;o!mo9 ' Adjust pupil location to just in front of the lens xs6kr parID = FindFullName( "Geometry.Arizona Eye" ) e_YTh^wU eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) =odK i "-6 count = 0 QXu[<V While GetOperationCount(eID)>count M3G ecjR GetOperation eID, count, op s^> >] If op.Type="ShiftZ" Then ~KQiNkA\|l DeleteOperation eID,count B3|G&Kg count=count-1 BgT(~8' End If [*J?TNk count=count+1 SM8f"H28 Wend )DGJr/) op.Type = "ShiftZ"
x7xMSy op.val1 = taq-0.01 1'!D
op.parent = parID d@%PTSX AddOperation eID, op _WR/]1R :6:,s#av Print "Set pupil diameter = " & pupilDiam bU \T pAws{3(Q 'Update AZ Eye subassembly Description )(9[> _+40 eID = FindFullName( "Geometry.Arizona Eye" ) "$/1.SX;] GetEntity eID, entity E!RlH3}) entity.Description = "Accommodation = " & A & "D" #-i#mbZ e SetEntity eID, entity O"X:3srJ` ]!]B7|JFJ Update Wo(m:q(Om Print "DONE!" ce[
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nDS\2 End Sub &hUEOif y=0)vi{] 如果屈光度是4,光瞳直径是4,则会输出如下数据: JEs@ky?{z ^ (s(4| Accommodation = 4 Diopters 7p-
RPC Pupil Diameter = 4 mm n[B[hAT Set aqueous humor thickness = 2.81 Qz89=#W Set anterior lens radius = 10.4 and conic constant = -2.375869 ~Ajst!Y7= Set posterior lens radius = -4.424557 and conic constant = -3.081019 Zoy)2E{ Set lens thickness = 3.927 {+]tx46$ Set lens index of refraction = 1.42672 j#U,zsv: Set pupil diameter = 4 |e<$ DONE!
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