| infotek |
2020-12-09 09:18 |
Arizona眼睛模型
简介
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= lT+N{[kLt* 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。 84c[ Z }/VSIS@Z 模型 *}Gu'EU
++CL0S$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。 yHxi^D] -hKtd3WbT
Table 1. AZ眼睛模型的定义 +||[H)qym 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. ~!ICBF~j ^" 4u1 光源 u`wT_?%w PF]Vt 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。 XaYgl&x'!x ;Rd\yAG KDYyLkI dr
图1. 光源和提示信息使用 =ve, ! 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。 y:dwx *Q9I _R;+}1G/ 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。 ,CjJO - 3L%g2`
图2. 字母F光源的设定方法光 DZ&AwF 6N'HXL UlQ
图3. 字母F在视网膜上位置点列图 (N$$N:ac[t 视网膜的散射 UdX aC= Q J!*Pg< 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。 4W+%`x_U] u^uo=/ o/p'eY:)
图4. 视网膜朗伯散射设定 (1}"I
RX. 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。 <=&7*8u0+ ;@I}eZ,f$ 21G:!t4/?n
图5. 视网膜重点采样规格设定 gfAVxMg 脚本 \ /6m p$&6E\#7 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: .@;,'Xw1~ Nx"v|"
图6. 用户对话框的创建与编辑 5A*'@Fr'G
图7. 用户对话框编辑器 T#w *5Qf 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。 LdY aJh~h 余下的脚本计算与屈光度有关的所有参数。 8v']>5S]# ^9I^A!w= 分析 "ktC1y1 Ue0Q| h 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 k0R;1lZ0n R7!^ M
图7. 字母F在视网膜上颜色分析 <jRs/?1R 脚本代码 Y&_1U/}h O5p]E7/e Option Explicit 'Remove this to enable non-dimensioned variables to be used. P1mPC AAt<{ Dim entity As T_ENTITY =rDIU&0Y Dim op As T_OPERATION #]5|Qhrr+ Dim mat As T_MODELMATERIAL Ig6>+Mw Dim A As Double jZ>'q/ Dim pupilDiam As Double ICgyCsZ, Dim eID As Long ^NTOZ0x~# Dim parID As Long |d1%N'Ll Dim count As Integer $MG. I[h Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 0yxMIX Dim tlens As Double, nlens As Double _[W`!#" Dim curv As Double, conic As Double kV Z5>D$ Dim ok As Long ;.r > }AfK=1yOa Sub Main !S',V&Yb q>q@ztt '用户输入对话框 <ST#<
$% Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ?$^qcpJCp TextBox 220,21,40,21,.TextBox1 'default: 0 4GRmo"S Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 mckrR$> OKButton 40,91,90,21 S,,3h0$X CancelButton 190,91,90,21 l<$c.GgFd Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1
<&'r_m TextBox 220,49,40,21,.TextBox2 'default: 4 [\&Mo]"0 End Dialog ]-aeoa# Dim dlg As UserDialog $|YIr7?R uOrvmb ok = Dialog (dlg) 7o+!Gts] ^eEj
5Rh If ok=0 Then 'cancel button was pressed +mT}};-TS Print "Execution cancelled." -$4%@Z End f. =4p^ End If [@= [<
_r n]@+<TA<uA 'Assign accommodation and pupil diameter & use defaults if field left empty }x1mpPND If dlg.TextBox1 = "" Then hqY9\,.C A = 0 'Default accommodation z~xN]= Else 1a90S*M A = CDbl(dlg.TextBox1) aM9St!i End If %Ys>PzM wDZFOx0#8 If dlg.TextBox2 = "" Then 6mBX{-Z[ pupilDiam = 4 'Default pupil diameter BifA&o% Else @:xO5L}Io pupilDiam = CDbl(dlg.TextBox2) WJU`
g End If S~F:%@,* j78xMGKO Print " " v-)eT Print "Accommodation = " & A & " Diopters" /)de`k" Print "Pupil Diameter = " & pupilDiam & " mm" Md
{,@ G k&DHQvfB ' Calculate new parameters with accommodation \sC0om, taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness FV$= l
% r[Q$w> Rant = 12.0 - 0.4*A 'Radius of anterior lens fwAN9zs CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens %MP s}B &U xN.vl Rpost = -5.224557 + 0.2*A 'Radius of posterior lens p^YE"2 - CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens J6 [x(T "\BP+AF tlens = 3.767 + 0.04*A 'Lens thickness gH\r# wy| 9rao&\eH nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction /@RnCjc' Mn~A;=%qF 'Adjust parameters to account for accommodation 9$Mi/eLG2N 45j+n.9=
'************************************************************************* jD^L < 'Aqueous thickness (Position of Lens) @mJN '************************************************************************* YC=BP5^ eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Op)0D:BmR GetCustomElement eID, entity bOck^1Hk y M:`hb$k: parID = FindFullName( "Geometry.Arizona Eye" ) @LL&ggV?
o@LjSQ5! ' Delete any shift(s) in z N`Bt|#R count = 0 UWn}0:6t While GetOperationCount(eID)>count v[a#>!;s GetOperation eID, count, op d;<n [)@ If op.Type="ShiftZ" Then 6eDIS|/ DeleteOperation eID,count fr#lH3 count=count-1 4nl>&AV End If g=Qga09 count=count+1 @IiT8B Wend U*&ZQw 50DPzn 'Set new shift in X^|oY]D op.Type = "ShiftZ" o@>c[knJ op.val1 = taq ($S{td; op.parent = parID BRD'5 1]| AddOperation eID, op '-i
tn Print "Set aqueous humor thickness = " & taq-0.55 "j a0,%3 n/,7ryu '************************************************************************* zi?'3T%Ie 'Radius and conic constant of anterior lens n~&R_"mv( '************************************************************************* +cV!=gDT eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) K%pmE?%,8 GetConic eID, entity, curv, conic oy r2lfz* .897Z|$VB SetConic eID, entity, 1/Rant, CCant 0X0D8H(7Q Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #Y5I_:k xeI ,Kz." '************************************************************************* phc1AN=[E 'Radius and conic constant of posterior lens
l#~FeD '************************************************************************* VNYLps@4H eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) /M3D[aR<d GetConic eID, entity, curv, conic Rm*}<JN31 D+SpSO7yg SetConic eID, entity, 1/Rpost, CCpost 5./
(fgx> Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ?UfZ VyHv+ 42wcpSp '************************************************************************* R&4E7wrdP 'Lens thickness (Position of posterior lens surface) \W}EyA '************************************************************************* `U g.c
yX-xVvlv@ parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,oG"wgf uWWv`bI>x ' Delete any z-shift(s) Wl#^Eu\g1W count = 0 Z>,X$Y6< While GetOperationCount(eID)>count xF/D YXC{8 GetOperation eID, count, op lXPn]iLJ If op.Type="ShiftZ" Then UeICn@)\y DeleteOperation eID,count =+"'=o count=count-1 1}BNG ,n End If 5i^vN"J count=count+1 9/$P_Q:3 Wend &!a2%%1#N `e9uSF:9C 'Set new z-shift *h4m<\^U op.Type = "ShiftZ" ,\M_q">npc op.val1 = tlens 5qr!OEF2 op.parent = parID hX_p5a1t AddOperation eID, op O0{ Print "Set lens thickness = " & tlens yo.SPd="Vx ,xz^k/. '************************************************************************* H n!vTB 'Lens index of refraction d*>k
]X@G '************************************************************************* -{*V)J_Co eID = FindMaterial( "Lens" ) vs@:L)GW\
GetModelMaterial eID, mat S1zw'!O5 Dq?HUb^X mat.Nd = nlens 0X?fDz}jd SetModelMaterial eID, mat n`}&,UA$4 Print "Set lens index of refraction = " & nlens 5lxq-E3 +=h!?<*C8 '************************************************************************* k@aP&Z~ 'Pupil diameter 5)zB/Ta< '************************************************************************* ,&?q}M eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) v,+l xY W[>Tq T63 'Adjust pupil diameter (trimming volume inner hole) #Q@6:bBzv t60/f&A#7H SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" DP_Pqn8p&M W{+0iAYnp ' Adjust pupil location to just in front of the lens 9(F?|bfk parID = FindFullName( "Geometry.Arizona Eye" ) ijqdZ+ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) %gMpV count = 0 R{o*O_qX While GetOperationCount(eID)>count mY8=qkZE GetOperation eID, count, op ];d:z[\P If op.Type="ShiftZ" Then `7%eA9*.m DeleteOperation eID,count ?+O|mX}`- count=count-1 ,;P`Mf'YC End If jN}7BbX count=count+1 +@uC:3jM Wend b2=Q~=Wc op.Type = "ShiftZ" 1ysLZ;K op.val1 = taq-0.01 \ui^
d op.parent = parID Hs}"A,V AddOperation eID, op (I[h.\% bus=LAJt= Print "Set pupil diameter = " & pupilDiam m=.7f9 h==GdS4 'Update AZ Eye subassembly Description .&x?`pER eID = FindFullName( "Geometry.Arizona Eye" ) Kc[u}
. U GetEntity eID, entity #KNq:@wp6 entity.Description = "Accommodation = " & A & "D" SfobzX}~Jh SetEntity eID, entity '+I
2$xE CotMV^ Update @*"<U] Print "DONE!" y]YS2^ Zc3:9 End Sub 9;Pu9s[q2 =@KY A(D 如果屈光度是4,光瞳直径是4,则会输出如下数据: Bb[0\Hs7 Fl+tbF Accommodation = 4 Diopters mYjiiql~ Pupil Diameter = 4 mm y]pN=<*h5 Set aqueous humor thickness = 2.81 KaQq[a Set anterior lens radius = 10.4 and conic constant = -2.375869 K# i*9sM Set posterior lens radius = -4.424557 and conic constant = -3.081019 l&sO?P[ / Set lens thickness = 3.927 0HJqsSZ$mW Set lens index of refraction = 1.42672 r{!"%03H_ Set pupil diameter = 4 CAFE}| DONE! D@(M+u9/% 9MtJo.A h,'mN\6t QQ:2987619807 9 QCpXy
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