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2022-02-25 09:52 |
Arizona眼睛模型
简介 |B\76Nk _2}/rwVg 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。 9A\\2Zz6F ,A0v 5Q< 模型 9}G<\y ) .MV1@s 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。 !}"P Hby5N Table 1. AZ眼睛模型的定义 [attachment=111140] ]99;7 v/Xz.?a\jF 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. 7;sF0oB5e Te>m9Pav 光源 EPEn"{;U `2G%&R,k"D 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。 ?y~"\iP f Q2U| [attachment=111141] 图1. 光源和提示信息使用 &w^:nVgl 0(A&m , 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。 x^ Y sXzu (~#-J7 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。 aSfAu!j) [attachment=111142] 图2. 字母F光源的设定方法光 gJOD+~ u&o<>d;) [attachment=111143] 图3. 字母F在视网膜上位置点列图
X;dUlSi ~=$d>ZNQ 视网膜的散射 (^)(#CxO msZ3%L 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 Z4T{CwD`D (+bt{Ma [attachment=111144] 图4. 视网膜朗伯散射设定 p$XvVzW#< RJD(c#r$ 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。 ,Q+.kAh !G 9u_D@A"aC` [attachment=111145] 图5. 视网膜重点采样规格设定 }FkF1?C *UdP1?Y 脚本 !z+'mF?V+X mqQC`Aqx: 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: [85tZr] [attachment=111146] 图6. 用户对话框的创建与编辑 R& HkWe [attachment=111147] 图7. 用户对话框编辑器 8+&Da U1=\ `)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。 vyruUYFWe 余下的脚本计算与屈光度有关的所有参数。 7hKfxw-X@ #8B4*gAM 分析 f"G-',O< `t]8 [P5 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 TmLfH
d [attachment=111148] 图7. 字母F在视网膜上颜色分析 poS=8mN8; 3s,a%GOk 脚本代码 j=PM] jG/@kh*m
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. eeOG(@@o(
r]bG,?| Dim entity As T_ENTITY 7n'Ww=ttI Dim op As T_OPERATION ?#/~BZR! Dim mat As T_MODELMATERIAL f2i9UZ$=e! Dim A As Double Vx=tP.BO] Dim pupilDiam As Double 6oq/\D$6~ Dim eID As Long s[u*~A Dim parID As Long pT<I!,~ Dim count As Integer V`"Cd?R0Z Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double i$XT Qr0K= Dim tlens As Double, nlens As Double b'(Hwc\ t Dim curv As Double, conic As Double `s_k+ g Dim ok As Long +-MieiKv q.d
qr< Sub Main n6#z{,W<3 E-HK=D&W/ '用户输入对话框 G8Zl[8 Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 d@+u&xrd TextBox 220,21,40,21,.TextBox1 'default: 0 @8|i@S@4 Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g"X!&$& OKButton 40,91,90,21 Q6%Pp_$k CancelButton 190,91,90,21 _5v]69C# Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 vH>s2\V" TextBox 220,49,40,21,.TextBox2 'default: 4 KzLkT7,y+ End Dialog vk|xYDD Dim dlg As UserDialog }ykc
AK3U 5DVSaI$ = ok = Dialog (dlg) Eyg F,>.4 c- "# If ok=0 Then 'cancel button was pressed 4siq Print "Execution cancelled." OBnvY2)Ri End cjf_,x End If ~p\r( B7G n<DZb`/uHZ 'Assign accommodation and pupil diameter & use defaults if field left empty cf*SWKs If dlg.TextBox1 = "" Then W%<z|
A = 0 'Default accommodation }n?D#Pk, Else >ToI$~84 A = CDbl(dlg.TextBox1) wo\O0?d3{ End If 3Hh u]5 lLNI5C If dlg.TextBox2 = "" Then 2mfG:^^c pupilDiam = 4 'Default pupil diameter GT-ONwVDq Else hGU 3DKHT pupilDiam = CDbl(dlg.TextBox2) muIJeQ.C End If ZtX\E+mC (iY2d_FQ[ Print " " OA&r8WK3 Print "Accommodation = " & A & " Diopters" }}4uLGu) Print "Pupil Diameter = " & pupilDiam & " mm" sm qUFo Ft?Yc 5 ' Calculate new parameters with accommodation /=:Fw}vt taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness dG}*M25 hCB _g Rant = 12.0 - 0.4*A 'Radius of anterior lens cs)R8vuB)z CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens G PL^!_ z]1g;j Rpost = -5.224557 + 0.2*A 'Radius of posterior lens Y|-:z@n6C CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens v'SqH,=d Q@cYHFi~+ tlens = 3.767 + 0.04*A 'Lens thickness Xb1is\JB <(BIWm* nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction zz-X5PFn qex::Qf 'Adjust parameters to account for accommodation r
['zp=9 UW-`k1 '************************************************************************* hGo/Ve+@ 'Aqueous thickness (Position of Lens) X92I==-w '************************************************************************* ~?KbpB| eID = FindFullName( "Geometry.Arizona Eye.Lens" ) b:x*Hjf GetCustomElement eID, entity _`xhP-,`S )H%RwV# parID = FindFullName( "Geometry.Arizona Eye" ) `k3sl
0z% -8&P1jrI ' Delete any shift(s) in z [q(}~0{"- count = 0 \;!g@?CA While GetOperationCount(eID)>count E=qfI>2U& GetOperation eID, count, op +l>X Z If op.Type="ShiftZ" Then /cx
Ei6I- DeleteOperation eID,count @mEB=X(-l= count=count-1 EP6@5PNZ End If U
sV?} count=count+1 h BzZJ/jn Wend /@6T~XY M sUpSXG-W/@ 'Set new shift in ?r^>Vk} op.Type = "ShiftZ" uEyu s96 + op.val1 = taq n/+G^:~_ op.parent = parID ^1X
6DH` AddOperation eID, op #Z}YQ$g Print "Set aqueous humor thickness = " & taq-0.55 oC(.u ? C40W@*6S2 '************************************************************************* 2jyxP6t 'Radius and conic constant of anterior lens {$v>3FG '************************************************************************* q(}#{OO eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Fc a_(jw GetConic eID, entity, curv, conic cfPQcB>A r\m2Oo)] SetConic eID, entity, 1/Rant, CCant HLl"=m1/> Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /(Ryh6M #
0/,teJk '************************************************************************* 5>rjL; 'Radius and conic constant of posterior lens S|T*-?| '************************************************************************* BU=Ta$#BZ eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) -m Sf`1l0 GetConic eID, entity, curv, conic ]wV_xZ)l^A )7a
4yTg!~ SetConic eID, entity, 1/Rpost, CCpost USbFUHdDc Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `B7? F$J j Ysg'Rl '************************************************************************* 3s Mmg` 'Lens thickness (Position of posterior lens surface) %DhLU~VX '************************************************************************* |JTDwmR qz|xow/ns@ parID = FindFullName( "Geometry.Arizona Eye.Lens" ) L7s
_3\ _&PF (/w ' Delete any z-shift(s) 5} 1qo7; count = 0 9D51@b6k While GetOperationCount(eID)>count xd]7?L@h.I GetOperation eID, count, op \"$jj<gc If op.Type="ShiftZ" Then Vet<,;Te DeleteOperation eID,count zA@w[. count=count-1 J24H}^~na End If !-q)9K? count=count+1 hr/|Fn+kA Wend iI!g1 tMr$N[@r 'Set new z-shift NucLf6 op.Type = "ShiftZ" ]0;,M op.val1 = tlens LgA>,. op.parent = parID dlc'=M AddOperation eID, op D?r% Y Print "Set lens thickness = " & tlens QykHB
k ~{!,ZnO* '************************************************************************* n2&M?MGX 'Lens index of refraction BmCBC,j<v> '************************************************************************* mH!\]fmR~ eID = FindMaterial( "Lens" ) ~JohcU}d GetModelMaterial eID, mat a>Xq qnf\K} mat.Nd = nlens IYB;X SetModelMaterial eID, mat <u2iXH5w Print "Set lens index of refraction = " & nlens j9 &0/
~/ _OR[RGy '************************************************************************* T$s )aM 'Pupil diameter n16TQe"8 '************************************************************************* e[t1V/ah eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) u|\K kk WvWZzlw 'Adjust pupil diameter (trimming volume inner hole) 8rSu,&< $EPDa?$* SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >2;KPV0H Y~I6ee,\ ' Adjust pupil location to just in front of the lens t2&} parID = FindFullName( "Geometry.Arizona Eye" ) 30L/-+r1 eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ??XtN.]7 count = 0 dsA::jR0P6 While GetOperationCount(eID)>count L'}^Av_+ GetOperation eID, count, op _<l 9j;6 If op.Type="ShiftZ" Then bv'Z~@<c DeleteOperation eID,count 9XW[NY#)# count=count-1 Ui;PmwQc& End If 8Nxyc>8K~ count=count+1 D }EH9d Wend nF{>RD op.Type = "ShiftZ" T( sEk op.val1 = taq-0.01 4t0-L]v4.* op.parent = parID 'K3%@,O AddOperation eID, op
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