Arizona眼睛模型
简介 )g:,_ 1s)| 1|WpKaMoq 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。 a!y,!EB+Qu V"by9p|V` 模型 d6@jEa- ?hJsN 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。 Mev-M2A LbX6p
Table 1. AZ眼睛模型的定义 ,J(5@8(>a 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. mOgOHb2 3hXmYz( 光源 y{`(|,[ )ehB)X 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。 }K/}(zuy1Y X`3vSCn ('**nP
图1. 光源和提示信息使用 =tc`:!$ 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。 |pH*
CCA qbU1qF/ 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。 [|[sYo (' Ko#3b
图2. 字母F光源的设定方法光 [CDX CV-z C9mzg
图3. 字母F在视网膜上位置点列图 c2/R]%`)9 视网膜的散射 rO(TG Z;fm;X%4 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。 2z.8rNwT WS1&3mOd y*}vG}e%
图4. 视网膜朗伯散射设定 <E[HlL 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。 tt7PEEf "$W|/vD+ [W9e>Nsp0
图5. 视网膜重点采样规格设定 QtnM(m 脚本 Ld\LKwo 5y%un 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: GX7 eRqz > c?.r"5#
图6. 用户对话框的创建与编辑 :Hzz{'
图7. 用户对话框编辑器 *>aZc:: 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。 #h gmUa 余下的脚本计算与屈光度有关的所有参数。 s%N` {=bg5I0|a 分析 jr,&=C( {d 1N& 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 qe5tcv}u X,WQ'|rC
图7. 字母F在视网膜上颜色分析 ZDOF 脚本代码 I|g@W_ G2CZwm{/f Option Explicit 'Remove this to enable non-dimensioned variables to be used. !,Xyl}
# E!zd( Dim entity As T_ENTITY Qp kKVLi Dim op As T_OPERATION vzY'+9q1. Dim mat As T_MODELMATERIAL $` Z>Lm* Dim A As Double a^*cZ?Ta Dim pupilDiam As Double aF&r/j+}o Dim eID As Long c*x J=Gz6d Dim parID As Long UF&0&`@ Dim count As Integer ny12U;'s, Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double pqyWv; Dim tlens As Double, nlens As Double z5XYpi_;[ Dim curv As Double, conic As Double 2BoFyL* Dim ok As Long FX
HAZ2/\ ^M`>YOU2+ Sub Main n-b>m7O( <|{L[ '用户输入对话框 1YOg1 n+k Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ?,ZELpg n TextBox 220,21,40,21,.TextBox1 'default: 0 V";mWws+?# Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 5f;n<EPy OKButton 40,91,90,21 BFBR/d[& CancelButton 190,91,90,21 z.eJEK Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :3f-9aRC! TextBox 220,49,40,21,.TextBox2 'default: 4 ;_mgiKHg End Dialog x96qd%l/ Dim dlg As UserDialog K :1g" 8[8|*8xqs ok = Dialog (dlg) @GN(]t&3 3jvx2 If ok=0 Then 'cancel button was pressed nd.57@*M Print "Execution cancelled." w Y8@1>ah End Z5((1J9 End If rHvF%o M{C6rm| 'Assign accommodation and pupil diameter & use defaults if field left empty R=!kbBK>\ If dlg.TextBox1 = "" Then (C,e6r Y A = 0 'Default accommodation iaY5JEV:CA Else :lUX5j3 A = CDbl(dlg.TextBox1) 'S =sj}X End If 8O,?|c=> L
;6b+I If dlg.TextBox2 = "" Then ?q\FLb%"7 pupilDiam = 4 'Default pupil diameter ~mtTsZc Else )VNM/o%Q pupilDiam = CDbl(dlg.TextBox2) +T9Q_e* End If Vwjk[ DOL k/% #> Print " " dVa!.q_3 Print "Accommodation = " & A & " Diopters" q[-|ZA bbr Print "Pupil Diameter = " & pupilDiam & " mm" W%TQYR TI}}1ScA' ' Calculate new parameters with accommodation FC6x Fg^ taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness +a|"{ Rv98\VD" Rant = 12.0 - 0.4*A 'Radius of anterior lens *'6s63)I2 CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens Kl{-z X YQ;
cJ$ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens ^V[/(Lq CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens JjQ8|En C@1CanL@3 tlens = 3.767 + 0.04*A 'Lens thickness u^Vh.g] 1!vPc93 $$ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction WE0}$P: j.DHqHx 'Adjust parameters to account for accommodation %dc3z"u nP<S6:s: '************************************************************************* wzd`l?o, 'Aqueous thickness (Position of Lens) Ejv%,q/T( '************************************************************************* ]fZ<`w8u} eID = FindFullName( "Geometry.Arizona Eye.Lens" ) t-WjL@$F/ GetCustomElement eID, entity w!\3ICB Y(_KizBY parID = FindFullName( "Geometry.Arizona Eye" ) Wbe0ZnM] -IadHX}]t ' Delete any shift(s) in z ygN>"eP count = 0 qe?Qeh(!X While GetOperationCount(eID)>count B@ {&< GetOperation eID, count, op 4jQ'+ 2it If op.Type="ShiftZ" Then
[>f]@> DeleteOperation eID,count <?YA,"~ count=count-1 %]!adro~ End If iRNLKi count=count+1 eX"''PA Wend qy
,"X)^# k^%2_H 'Set new shift in {pWBwf>R C op.Type = "ShiftZ" Fi4UaJ3K op.val1 = taq )s)_XL op.parent = parID 7NJFWz! AddOperation eID, op wO7t!35 Print "Set aqueous humor thickness = " & taq-0.55 x0A7O u`_*g^5q" '************************************************************************* &+01+-1hW 'Radius and conic constant of anterior lens ]!Oue_-; '************************************************************************* *nRNg.i3D eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) yS!(Ap GetConic eID, entity, curv, conic hJf2o {:bN/zV# SetConic eID, entity, 1/Rant, CCant )#C
mQXgG Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant .po>qb6 e"k/d< '************************************************************************* _okWQvdH 'Radius and conic constant of posterior lens "$| Zr '************************************************************************* ?qmp_2:WU eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ~}'F887 f GetConic eID, entity, curv, conic dz-y}J11 )*|(i] SetConic eID, entity, 1/Rpost, CCpost )&,{?$ . Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #H~_K}Ks FJ54S '************************************************************************* .Q* 'r&n 'Lens thickness (Position of posterior lens surface) Xgat-cy'DA '************************************************************************* Zgamd1DJ[l W2]TRO parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^A9M;q !l 6dg& ' Delete any z-shift(s) Zb_apjg[4 count = 0 <+v{GF#R While GetOperationCount(eID)>count ^zr^ N?a GetOperation eID, count, op XRtD< jlA" If op.Type="ShiftZ" Then 8 lT{1ro DeleteOperation eID,count G$bJ+ count=count-1 RLVATM5 End If pHC/(6? count=count+1 0N;%2=2_E Wend 4w93}t.z 28I^$> [ 'Set new z-shift V
'.a)6 op.Type = "ShiftZ" *
F4UAQzYb op.val1 = tlens `@Oa lg op.parent = parID w7TJv4_ AddOperation eID, op rD
&D)w Print "Set lens thickness = " & tlens ezm&]F` @'6"7g '************************************************************************* ;9a 6pz< 'Lens index of refraction I&VTW8jB '************************************************************************* vXE0%QE'Q eID = FindMaterial( "Lens" ) |~0UM$OB^3 GetModelMaterial eID, mat 0~Gle: 5's~>up& mat.Nd = nlens >jg0s)RA' SetModelMaterial eID, mat 3=mr
"&]r: Print "Set lens index of refraction = " & nlens K.~q+IYP[ WXw}^v '************************************************************************* I/6)3su% 'Pupil diameter HD>q(cK_|8 '************************************************************************* YJeyIYCs< eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) d+eZub94U S\i@s_ 'Adjust pupil diameter (trimming volume inner hole) ~f\G68c 3uWkc3 SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }H> ^o9 c9"r6j2m5 ' Adjust pupil location to just in front of the lens #W>QY Tp parID = FindFullName( "Geometry.Arizona Eye" ) V)ig)(CT eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) VqSc;w count = 0 zP\7S}p7% While GetOperationCount(eID)>count w;6bD'.>; GetOperation eID, count, op KngTc(^_D If op.Type="ShiftZ" Then =FP0\cQ. DeleteOperation eID,count co8"sz0(U count=count-1 o\b- _E5"? End If "qz3u`[o count=count+1 'a6<ixgo0 Wend \y`+B*\i op.Type = "ShiftZ" W,5Hx1z R op.val1 = taq-0.01 n{*D_kM(H op.parent = parID r0;:t AddOperation eID, op {76c%<`WaP !E8X~DJ Print "Set pupil diameter = " & pupilDiam <7SpEVQ x!LQxoNF 'Update AZ Eye subassembly Description S-Y=-" eID = FindFullName( "Geometry.Arizona Eye" ) [epi#]m GetEntity eID, entity E>'a,!QPv entity.Description = "Accommodation = " & A & "D" 2Y\
d<.M SetEntity eID, entity `]Fx.)C# &Mq~T_S Update #'D"
'B Print "DONE!" ,2Q o7(A V&8VwF^- End Sub nRL. ppUI -i0(2*< 如果屈光度是4,光瞳直径是4,则会输出如下数据: ,mhQ"\ +C BS Iy+ Accommodation = 4 Diopters xsd_Uu* Pupil Diameter = 4 mm y&}E~5O Set aqueous humor thickness = 2.81 ~(!XY/0e Set anterior lens radius = 10.4 and conic constant = -2.375869 |F,R&<2 Set posterior lens radius = -4.424557 and conic constant = -3.081019 "k*PA\U Set lens thickness = 3.927 3.22"U\1: Set lens index of refraction = 1.42672 ;c~cet4 Set pupil diameter = 4 m(RXJORI DONE! k.("3R6v:
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