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2022-02-25 09:52 |
Arizona眼睛模型
简介 slPLc w&U>w@H^ 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。 $K-od3h4= qC|$0 模型 0{0A,;b b&iJui"7k 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 7R4xJ H Table 1. AZ眼睛模型的定义 [attachment=111140] ik:fq&= HzuB.B< 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. Y#[Wv1hi :>G3N+A) 光源 iRwlK5(& e/S^Rx4W 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 8AX+s\N \7l%@ [attachment=111141] 图1. 光源和提示信息使用 7"|j.Yq$H{ 1ig#|v*+ 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。 dF
(m!P/R ]Sl]G6#Iwv 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。 f*uD9l%/ [attachment=111142] 图2. 字母F光源的设定方法光 c+_F}2)
V(/=0H/ F [attachment=111143] 图3. 字母F在视网膜上位置点列图 zLeId83> yEvuTgDv 视网膜的散射 qYi<GI*|@ d|~A>YZ 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。 B^{87YR Hf^Tok^6@] [attachment=111144] 图4. 视网膜朗伯散射设定 }3rWmo8V d7O\p(M1 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。 Td6Gu" N=?! ~n9Q- [attachment=111145] 图5. 视网膜重点采样规格设定 Y$L>tFA *CnrzrKtQ 脚本 !uno!wUIYd c2$&pZ
M 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: J &<uP)< [attachment=111146] 图6. 用户对话框的创建与编辑 QqS?- [attachment=111147] 图7. 用户对话框编辑器 P0/B!8x `/1Zy}cD 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。 8N58w)%7` 余下的脚本计算与屈光度有关的所有参数。 K9BoIHo s</llJ$ 分析 Nvef+L,v p]7Gj&a 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 tG{? [attachment=111148] 图7. 字母F在视网膜上颜色分析 /nX+*L}d/ /p&)bL 脚本代码 '
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- Option Explicit 'Remove this to enable non-dimensioned variables to be used. lQ}e"#<
wG&+*,} Dim entity As T_ENTITY /G>reG,G Dim op As T_OPERATION ,;_D~7L Dim mat As T_MODELMATERIAL ~6hG"t]: Dim A As Double H$
sNp\[{ Dim pupilDiam As Double )kE(%q:*P$ Dim eID As Long bnWKfz5 Dim parID As Long i"rrM1/r
Dim count As Integer ,0~/ Cn
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double $B
iG7,[# Dim tlens As Double, nlens As Double C~5-E{i Dim curv As Double, conic As Double `tCOe Dim ok As Long M?UlC
>Kd(.r[Er Sub Main Kk^tQwj/QE >:ZlYZ6sI '用户输入对话框 _n3Jf<Y Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 N1V qK TextBox 220,21,40,21,.TextBox1 'default: 0 ;5*)kX Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Wu
71q= OKButton 40,91,90,21 :*2+t- CancelButton 190,91,90,21 +njE Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 V zx%N. TextBox 220,49,40,21,.TextBox2 'default: 4 ,]N!I%SI End Dialog qdn\8Pn Dim dlg As UserDialog 6g ,U+~ Z{ntF ok = Dialog (dlg) 5T[9|zJs 35Jno<TP' If ok=0 Then 'cancel button was pressed C/P,W>8 Print "Execution cancelled." -S=Zsr\ End ^"w.v' sL End If HY]vaA` dkV%Pyj 'Assign accommodation and pupil diameter & use defaults if field left empty 7p?6j)rj If dlg.TextBox1 = "" Then @"}dbW <DV A = 0 'Default accommodation J! 4l-.- Else f77uqv(Y A = CDbl(dlg.TextBox1)
,i2%FW End If B;8YX>r JH~v e If dlg.TextBox2 = "" Then .P=uR8 pupilDiam = 4 'Default pupil diameter JlsRP Else *JG?^G"l pupilDiam = CDbl(dlg.TextBox2) S.+)">buH End If i3.8m=> 5 TD" Print " " _"Q
+G@@ Print "Accommodation = " & A & " Diopters" E<3hy Print "Pupil Diameter = " & pupilDiam & " mm" q{UP_6OF tUq* -9
V ' Calculate new parameters with accommodation Y2Mti-\ taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness r'hr'wZ #K7i<Bf Rant = 12.0 - 0.4*A 'Radius of anterior lens W%09.bF CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens u[U~`*i*rA vd-`?/,|| Rpost = -5.224557 + 0.2*A 'Radius of posterior lens KQ/v](77 CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens Z*kGWL \n850PS tlens = 3.767 + 0.04*A 'Lens thickness [;VNuF :~^ec|tp nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction 2
G_*Pqc DR9M8E 'Adjust parameters to account for accommodation 3V`K^X3 5(MWgC1 '************************************************************************* jh]wHG 'Aqueous thickness (Position of Lens) $*%Ml+H- '************************************************************************* .i/]1X*;r^ eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~}4o=O( GetCustomElement eID, entity uw+v]y n?pCMS| parID = FindFullName( "Geometry.Arizona Eye" ) }i/&m&VU w;'
F;j~ ' Delete any shift(s) in z #hd<5+$U}l count = 0 AEi@t0By While GetOperationCount(eID)>count 'N5qX>Ob GetOperation eID, count, op q4 'x'8 If op.Type="ShiftZ" Then xP'IyABx DeleteOperation eID,count <_ */ count=count-1 )QTk5zt End If nl5K1!1 count=count+1 %>i7A?L Wend i TD}gC ~>D;2 S(a 'Set new shift in c0<Y017sG op.Type = "ShiftZ" $t1]w]}d op.val1 = taq 6kT
l(+ op.parent = parID #X"\:yN AddOperation eID, op |i?AtOt@f Print "Set aqueous humor thickness = " & taq-0.55 $Miii`VS9 ]Nt97eD) '************************************************************************* X@9_ukdpu 'Radius and conic constant of anterior lens 'A!Dg '************************************************************************* =Mn![ eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 30>TxL=& GetConic eID, entity, curv, conic I2j;9Qcz )0AE*S SetConic eID, entity, 1/Rant, CCant 4,s: G.g Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant )\^o<x2S ]vQo^nOo '************************************************************************* RO wbzA)]r 'Radius and conic constant of posterior lens lbg6n:@ '*************************************************************************
UUb!2sO eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ;
tvB{s_ GetConic eID, entity, curv, conic (GPJ=r (^a;2j9 SetConic eID, entity, 1/Rpost, CCpost z8Dn<h Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost (P`{0^O"} e,~c~Db*
Q '************************************************************************* jI;bVG
'Lens thickness (Position of posterior lens surface) |,sUD/rt '************************************************************************* Y[s nZ\,ZqV parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5\=9&{WjND i'e^[oZ ' Delete any z-shift(s) N%r}0 count = 0 lBG*P>; While GetOperationCount(eID)>count aGpRdF1;! GetOperation eID, count, op >j`*-(`2fa If op.Type="ShiftZ" Then QV .A.DK DeleteOperation eID,count ~iwEhF count=count-1 'R]Z9h End If RX2=
iO" count=count+1 y\0^c5} Wend |!!E5osXq E 3I'3 'Set new z-shift z%Z}vWn op.Type = "ShiftZ" 3:Z(tM&-O op.val1 = tlens lf|^^2'*2< op.parent = parID ['R=@. AddOperation eID, op J1R%w{ Print "Set lens thickness = " & tlens =r-Wy.a@ mu{%%b7|^ '************************************************************************* ,s)~Y
p?< 'Lens index of refraction 2OT6*+D '************************************************************************* VsZ_So; eID = FindMaterial( "Lens" ) &PgdCijGq; GetModelMaterial eID, mat f "&q~V4? ~!&[;EM<bm mat.Nd = nlens \~?s= LT SetModelMaterial eID, mat *(>$4$9n Print "Set lens index of refraction = " & nlens /pk;E$qv ZcWl{e4 '************************************************************************* "5y^s!/ 'Pupil diameter Bp/8 >EO` '************************************************************************* \FKIEg+(2 eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Y4714 ZDDwh&h 'Adjust pupil diameter (trimming volume inner hole) bs`/k&' =VY4y]V SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" %@xYg{ ?x[>g!r ' Adjust pupil location to just in front of the lens xK
y<o parID = FindFullName( "Geometry.Arizona Eye" ) [KE4wz+s{ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) jU#%@d6!# count = 0 `q@~78` While GetOperationCount(eID)>count \) #3S $L~ GetOperation eID, count, op HkV/+ {;S~ If op.Type="ShiftZ" Then +nZG!nP DeleteOperation eID,count R|M:6]}
count=count-1 (qG$u& End If .XE]vo count=count+1 (,TO| Wend nx+&
{hn( op.Type = "ShiftZ" '9[_w$~( op.val1 = taq-0.01 (\I =v". op.parent = parID &%bX&;ECzf AddOperation eID, op e=R}
4` :Aa^afjJw Print "Set pupil diameter = " & pupilDiam .iS]aJJ <'B^z0I, 'Update AZ Eye subassembly Description Sh*P^i.]+ eID = FindFullName( "Geometry.Arizona Eye" ) <|_Ey)1
6 GetEntity eID, entity A^Zs?<C- entity.Description = "Accommodation = " & A & "D" \mDm*UuG
SetEntity eID, entity avz 4& ie,{C Update <?g{Rn Print "DONE!" GkC88l9z !INr End Sub C;ye%&g> xV6j6k 如果屈光度是4,光瞳直径是4,则会输出如下数据: ={Hbx>p 4<Y?#bm' Accommodation = 4 Diopters *,pqpD> Pupil Diameter = 4 mm t(yv Set aqueous humor thickness = 2.81 [~o3S$C&7 Set anterior lens radius = 10.4 and conic constant = -2.375869 xle29:?l Set posterior lens radius = -4.424557 and conic constant = -3.081019 ?`XKaD!
f Set lens thickness = 3.927 Cnr48ukq Set lens index of refraction = 1.42672 `otQ'e~+t Set pupil diameter = 4 RW)C<g DONE!
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