-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2025-11-19
- 在线时间1888小时
-
-
访问TA的空间加好友用道具
|
简介 ,>bGbx [):{5hMA 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。 ?qd,> Ie G7@ 模型 ^eTDD wMH[QYb<* 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。 {h/OnBwG lj
"Z Table 1. AZ眼睛模型的定义 p3M#XC_H] 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. kfMhw M8kP TIcd
_>TW 光源 w?]ZU- z+3<$Z 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 ~-XOvKJb Fb<n0[m 1s{ISWm 图1. 光源和提示信息使用 [,OJX
N-4s 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 55 S\&Ad$ L.C
^E7;Z_ 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。 Qqd6.F ioB|*D<U2 图2. 字母F光源的设定方法光 T"L0Iy!k; !cq=)xR 图3. 字母F在视网膜上位置点列图 Zi 2o 视网膜的散射 .ocx(_3G t$U3|r 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 q+YuVQ-fx E
S#rs=" Ad dGB^7yl 图4. 视网膜朗伯散射设定 [<]Y+33 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 1 L+=|*: 4`'8fe/" Um]p&phVL 图5. 视网膜重点采样规格设定 6-mmi7IfO 脚本 Ze-MAt U8CWz!;Qz 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: GE%2/z p -'I _*fu 图6. 用户对话框的创建与编辑 UH5w7M 图7. 用户对话框编辑器 Sa%zre@ 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 uz ]E_&2 余下的脚本计算与屈光度有关的所有参数。 :=rA Yc3] 54<6Dy f 分析 aRbx RXGHD19] 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 .qSBh
hH\ ;knd7SC 图7. 字母F在视网膜上颜色分析 Nc{]zWL9 脚本代码 ;(K 1s Br.+p Option Explicit 'Remove this to enable non-dimensioned variables to be used. Hl4\M]]/& 7N>oY$&) Dim entity As T_ENTITY vT?Q^PTO Dim op As T_OPERATION CXTt(-FT Dim mat As T_MODELMATERIAL *i`v~> Dim A As Double ]\OWZ{T'j Dim pupilDiam As Double !tI=`Ml[ Dim eID As Long A^pu Dim parID As Long d4%dIR) Dim count As Integer 4py(R-8\ Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Y5HfN[u^7 Dim tlens As Double, nlens As Double I[ai: Dim curv As Double, conic As Double HeCcF+ Dim ok As Long :v`o6x8 mV<i JZh Sub Main , 7Xqte Xq|nJ|h '用户输入对话框 (B&h;U$HAH Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 UV4u.7y TextBox 220,21,40,21,.TextBox1 'default: 0 prZ55MS. Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 WE")xhV6 OKButton 40,91,90,21 K'NcTw#f CancelButton 190,91,90,21 o
w2$o\hC Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 cqEHYJ;B TextBox 220,49,40,21,.TextBox2 'default: 4 ,*dzJT$k End Dialog <{giHT Dim dlg As UserDialog BBvZeG $Y yIOLs}!SF ok = Dialog (dlg) h2% J/69 M`~!u/D7 If ok=0 Then 'cancel button was pressed $_)=8"Sn Print "Execution cancelled." +jtA&1cf End :7\9xH End If
a"QU:<-v f/ajejYo?, 'Assign accommodation and pupil diameter & use defaults if field left empty 3%^z ?_ If dlg.TextBox1 = "" Then >\ZR*CS A = 0 'Default accommodation H>.B99vp Else pW{8R^vKm A = CDbl(dlg.TextBox1) %w7m\nw@ End If i&A%"lOI9 Tw//!rpG If dlg.TextBox2 = "" Then rs:Q%V
^ pupilDiam = 4 'Default pupil diameter azo0{`S? Else _R7 w?!t8 pupilDiam = CDbl(dlg.TextBox2) B;!f<"a8 End If )r9b:c\ w>qCg XU3
Print " "
: tM?%=Q Print "Accommodation = " & A & " Diopters" c&f
y{}10 Print "Pupil Diameter = " & pupilDiam & " mm" ANMYX18M Gy!P,a)z ' Calculate new parameters with accommodation .Pw%DZ' taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness PKA }zZ 6e .v&f7( Rant = 12.0 - 0.4*A 'Radius of anterior lens Qw?+!-7TN CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens .^[_V )p8I@E Rpost = -5.224557 + 0.2*A 'Radius of posterior lens "}b'E# CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens 1zjaR4Tf %jEY3q tlens = 3.767 + 0.04*A 'Lens thickness K;U39ofW 6z?gg3GV nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction aV>aiR= m&IsDAn 'Adjust parameters to account for accommodation WJ+>e+ z<pJYpxH '************************************************************************* Km3&N 'Aqueous thickness (Position of Lens) ([ dT!B#aH '************************************************************************* 3bs4mCq eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :EZQ'3X GetCustomElement eID, entity Ftv8@l \iU] s\{). parID = FindFullName( "Geometry.Arizona Eye" ) mJC3@V
s rg5]&<Vq8 ' Delete any shift(s) in z )NT5yF,m count = 0 ~|lIC !q While GetOperationCount(eID)>count :eOR-}p' GetOperation eID, count, op u@=?#a$$ If op.Type="ShiftZ" Then (9$"#o DeleteOperation eID,count Ht[{ryTxu count=count-1 }nud End If jtKn3m7 +p count=count+1 a3@w|KLt Wend aMK~1]Cx l#bAl/c` 'Set new shift in IfV
3fJ7 op.Type = "ShiftZ" Ct]A%=cZW op.val1 = taq [pgZbOIN37 op.parent = parID <7n]Ai@Y AddOperation eID, op 8)xt(~qF Print "Set aqueous humor thickness = " & taq-0.55 otr>3a*' pCU*@c! '************************************************************************* SwH2$:f 'Radius and conic constant of anterior lens #Hu~}zy '************************************************************************* PlCc8Zy eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) :reTJQwr GetConic eID, entity, curv, conic vR>o}%` v6uxxsI>Hm SetConic eID, entity, 1/Rant, CCant )1F<6R Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant h`5)2n+ P I*\^,ow '************************************************************************* Bct"X#W|& 'Radius and conic constant of posterior lens uQeu4$k! '************************************************************************* QH@>icAb eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) $'"8QOnJ?k GetConic eID, entity, curv, conic *'ZN:5%H o-eKAkh SetConic eID, entity, 1/Rpost, CCpost vtxvS3
Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 2KI!af[I m)&znLA '************************************************************************* O}Le]2' 'Lens thickness (Position of posterior lens surface) Bjj<\8^M '************************************************************************* 5bX6#5uP1 9E1W|KE parID = FindFullName( "Geometry.Arizona Eye.Lens" ) u oVNK HGDVOJq ' Delete any z-shift(s) S~F` count = 0 p!W[X%`) While GetOperationCount(eID)>count )\ 0F7Z GetOperation eID, count, op 5/I_w0 If op.Type="ShiftZ" Then ,&]MOe4@> DeleteOperation eID,count SR7j\1a/2A count=count-1
Xm_$
dZ End If v[S-Pi1 count=count+1
RiFw?Q+ Wend l]#!+@ ?m"|QS!!K 'Set new z-shift 'Bq ZOZw op.Type = "ShiftZ" wu~hqd op.val1 = tlens wH6u5*$p op.parent = parID k%Vv?{g AddOperation eID, op raB+,Oi$G Print "Set lens thickness = " & tlens 3$p#;a:=n Yx)o:#2 '************************************************************************* NHaMo*xQ 'Lens index of refraction ;b%{ilx: '************************************************************************* XutF"9u eID = FindMaterial( "Lens" ) :FQ1[X1xm GetModelMaterial eID, mat bEH
de*q( \54}T4R mat.Nd = nlens |V&G81sM SetModelMaterial eID, mat 3h=8"lRc Print "Set lens index of refraction = " & nlens pyB~M9Bp/ Cmd329AH '************************************************************************* M}F~_S0h 'Pupil diameter ;;&F1@3tBa '************************************************************************* r%=[},JQ eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Q~,YbZ-7
<!'M} s 'Adjust pupil diameter (trimming volume inner hole) mJ <'m6^]: SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <,8l *1C 4zc<GL3[ ' Adjust pupil location to just in front of the lens a/:XXy | parID = FindFullName( "Geometry.Arizona Eye" ) m *X7T eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) WS0JS' count = 0 Ex(3D[WmMW While GetOperationCount(eID)>count ;Ss$2V'a GetOperation eID, count, op jX
*/piSq If op.Type="ShiftZ" Then ;4~U,+Av DeleteOperation eID,count nkY@_N count=count-1 ;+_8&wbqW End If 3fkk
[U count=count+1 PEXq:TA Wend _a'A~JY op.Type = "ShiftZ" 8b&uU [ op.val1 = taq-0.01 H7&xLYQ2 op.parent = parID (H#M<N AddOperation eID, op FxU'LN<;HY *i%quMv Print "Set pupil diameter = " & pupilDiam %FA@)?~ 6Z! y 'Update AZ Eye subassembly Description T0e<Slo~C eID = FindFullName( "Geometry.Arizona Eye" ) < |