-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2025-12-12
- 在线时间1894小时
-
-
访问TA的空间加好友用道具
|
简介 2tK~]0x O;VqrO 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。 bsu?Q'q
@].s^ss9_ 模型 .K~V DUu *m"@*O' 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。 k`>qb8, zk$h71<{. Table 1. AZ眼睛模型的定义 +DSbr5"VlB 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. -!+i
^r \Nik`v*Pd 光源 =Jl\^u%H(x &H# l* 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。 4mY^pQ1=L 9ls1y=M8J e[x,@P` 图1. 光源和提示信息使用 uvl91~&G 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。 7vgRNzZoq O8hx}dOjA 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。 <6]Hj2 {0j,U\ kb 图2. 字母F光源的设定方法光 $]?pAqU\ xy>$^/[$ 图3. 字母F在视网膜上位置点列图 fQ~~%#z1 视网膜的散射 BpA7
z / f|~'(~Sr 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。 `ci
P dh]Hf,OLF u@D5SkT 图4. 视网膜朗伯散射设定 0e>?!Z
E 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。 +q2\3REzx 8Ie0L3d- Y]R=z*i% 图5. 视网膜重点采样规格设定 LL:N/1ysG 脚本 nS$4[!0 CNuE9|W(vI 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示:
T\zn&6 s7E %Et 图6. 用户对话框的创建与编辑 K&._fG 图7. 用户对话框编辑器 e{2Za 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 \zVp8MMf 余下的脚本计算与屈光度有关的所有参数。 aEQrBs :zC=JvKT 分析 hQ%X0X, g0~m[[ 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 fm^tU0DY S%]4['Y 图7. 字母F在视网膜上颜色分析 2hntQ1[ 脚本代码 'lC=k7@x 4cm~oZ Option Explicit 'Remove this to enable non-dimensioned variables to be used. Lo'GfHE tm34Z''.> Dim entity As T_ENTITY +7"UF)
~k Dim op As T_OPERATION B$=1@ Dim mat As T_MODELMATERIAL /;TD n>lq Dim A As Double HU
+271A8 Dim pupilDiam As Double brE%/%!e Dim eID As Long K~&3etQF Dim parID As Long WFug-#;e Dim count As Integer %RIu'JXi Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Zjc/GO Dim tlens As Double, nlens As Double UHl1>(U Dim curv As Double, conic As Double F":dS-u&L Dim ok As Long R $/q=*k M+=q"#& Sub Main i+-=I+L3 MmfshnTN '用户输入对话框 qqYQ/4Ajw Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 u 8~5e TextBox 220,21,40,21,.TextBox1 'default: 0 Dxr4B< Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 C`oB [ OKButton 40,91,90,21 a<pEVV\NB~ CancelButton 190,91,90,21 iee`Yg!EOH Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 -RThd" TextBox 220,49,40,21,.TextBox2 'default: 4 IxlPpS9Wx End Dialog H'2o84$ Dim dlg As UserDialog sGMnm )A;jBfr ok = Dialog (dlg) FP6JfI8 0"@p|nAa If ok=0 Then 'cancel button was pressed z_&T>ME Print "Execution cancelled." G~lnX^46" End /X\:3P End If Z!?T&: K!88 Nox( 'Assign accommodation and pupil diameter & use defaults if field left empty FZ%
WD@= If dlg.TextBox1 = "" Then l~`JFWur] A = 0 'Default accommodation y3 S T"U Else 61K:SXj
A = CDbl(dlg.TextBox1) No/D"S# End If 6:TA8w| 4,6?sTuX If dlg.TextBox2 = "" Then `? f sU pupilDiam = 4 'Default pupil diameter 7
(i\? Else X 0m6<q pupilDiam = CDbl(dlg.TextBox2) <,'^dR7, End If 0vz!) 5sMyH[5zY Print " " TP/bPZY Print "Accommodation = " & A & " Diopters" zL:k(7E Print "Pupil Diameter = " & pupilDiam & " mm" k*T&>$k}^ QTI^?@+N> ' Calculate new parameters with accommodation iHOvCrp+X taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness ,6\oT;G 8x6{[Tx
Rant = 12.0 - 0.4*A 'Radius of anterior lens x8h=3e$ CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens $5yH8JU -Ly A Rpost = -5.224557 + 0.2*A 'Radius of posterior lens g>Kh? ( CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens Ils^t _k5-Wd5Ypw tlens = 3.767 + 0.04*A 'Lens thickness x@"`KiEUs 0bMbM^xV6 nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction yCye3z.
Zv1/J}+ 'Adjust parameters to account for accommodation BO=j*.YKy Q%RI;;YyA '************************************************************************* IQ}YF]I; 'Aqueous thickness (Position of Lens) fxX4 !r '************************************************************************* `lq[6[n eID = FindFullName( "Geometry.Arizona Eye.Lens" ) X=b]Whuv GetCustomElement eID, entity K"ytE2:3 X1~ B parID = FindFullName( "Geometry.Arizona Eye" ) V_7QWIdiy> N u9+b"Wr ' Delete any shift(s) in z lF1ieg"i M count = 0 qeZ*!H6- While GetOperationCount(eID)>count v/DWy(CC GetOperation eID, count, op xYWg1e$k If op.Type="ShiftZ" Then #kDJ>r |&- DeleteOperation eID,count syLpnNx= count=count-1 C")NNs= End If Q|J$R count=count+1 XB-l[4? Wend BnLE+X ~C2[5r{So 'Set new shift in 0(dXU\Y op.Type = "ShiftZ" t12 xPtN1 op.val1 = taq *6%r2l'kZ op.parent = parID f)K1j{TZ AddOperation eID, op 'gwh:8Xc Print "Set aqueous humor thickness = " & taq-0.55 <swYo<?J# .EQ1r7
9, '************************************************************************* -J=N 'Radius and conic constant of anterior lens $3MYr5
'************************************************************************* u9%)_Q!14 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) JdeGQ GetConic eID, entity, curv, conic s\dF7/b c 7uryL SetConic eID, entity, 1/Rant, CCant F45UO%/P Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant u0& dDZ K2R[u#Q '************************************************************************* x,SzZ)l-9 'Radius and conic constant of posterior lens L>EC^2\ '************************************************************************* ~'l.g^p bv eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) -=D6[DjU< GetConic eID, entity, curv, conic HJu;4O($ C|A:^6d3= SetConic eID, entity, 1/Rpost, CCpost h
.$3jNU Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost K+_$
WT_ x GHS '************************************************************************* M%8: 'Lens thickness (Position of posterior lens surface) pP6pn~} '************************************************************************* %A<|@OSdOa 0vRug|}k#% parID = FindFullName( "Geometry.Arizona Eye.Lens" ) hVcV_ [!E8 C9Q#! ' Delete any z-shift(s) -Fj:^q:@u count = 0 y$e'- v While GetOperationCount(eID)>count {~ngI< GetOperation eID, count, op <v)Ai;l, If op.Type="ShiftZ" Then CdRgI^5 DeleteOperation eID,count 5'Fh_TXTD count=count-1 9H<6k* End If 3[L)q2;}$N count=count+1 'nM)= Wend EI29; [=Yfdh
M8S 'Set new z-shift x-_!I>l& op.Type = "ShiftZ" Nz&J&\X)tD op.val1 = tlens 7QlA/iKqK op.parent = parID f}'E|:Z 7k AddOperation eID, op 04wmN Print "Set lens thickness = " & tlens J!:ss ega< {t '************************************************************************* |'2E'?\/x 'Lens index of refraction Pxj?W'| '************************************************************************* *zy0,{bl eID = FindMaterial( "Lens" ) @Ooh}V#J GetModelMaterial eID, mat Z=Oo%lM6B 46dh@&U mat.Nd = nlens ,z?Re)qm SetModelMaterial eID, mat <o_H]c-> Print "Set lens index of refraction = " & nlens q
lL6wzq, l\yFx '************************************************************************* #isBE}sT{ 'Pupil diameter j!;?=s '************************************************************************* .s_wP eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) H!ZPP8]j> ?hS n) 'Adjust pupil diameter (trimming volume inner hole) !5}Ibb X}yEMe{T SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ?.:C+*+ ]y,6 ' Adjust pupil location to just in front of the lens *fq=["O parID = FindFullName( "Geometry.Arizona Eye" ) 1(Kd/%]{ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 0j1I count = 0 j+n1k^jC While GetOperationCount(eID)>count %cD7}o:u GetOperation eID, count, op AR?J[e If op.Type="ShiftZ" Then oUm"qt_ DeleteOperation eID,count Xv'M\T}6C+ count=count-1 `n7z+ End If ,2)LH'Xx count=count+1 NwmO[pt+ Wend 'Z-jj2t} op.Type = "ShiftZ" h]<Ld9 op.val1 = taq-0.01 p3*}! ez4 op.parent = parID !9i,V{$c`" AddOperation eID, op c8gdY` 3_IuK6K2 Print "Set pupil diameter = " & pupilDiam i` Es7 } v"L<{HN 'Update AZ Eye subassembly Description }abM:O
"Y eID = FindFullName( "Geometry.Arizona Eye" ) ~?dPF;.6_ GetEntity eID, entity _.Y?BAQ entity.Description = "Accommodation = " & A & "D" +GWeu0b(~ SetEntity eID, entity @7%nMTZ@&v POc<
G^ Update kzGD* Print "DONE!" PKu+$ O~B
iqm End Sub z48,{H6h
Xi5ZQo!t 如果屈光度是4,光瞳直径是4,则会输出如下数据: . #;ZM[v 0?ZJJdI3 Accommodation = 4 Diopters qU#Gz7/ Pupil Diameter = 4 mm 7,_N9Q]rB Set aqueous humor thickness = 2.81 u9e A"\s Set anterior lens radius = 10.4 and conic constant = -2.375869 ?T70C9 Set posterior lens radius = -4.424557 and conic constant = -3.081019 K%>uSS? Set lens thickness = 3.927 lx~!FLn Set lens index of refraction = 1.42672 V$-IRdb Set pupil diameter = 4 &`<j!xlG DONE! OUe@U;l{Z G6Z2[Ej1 ?K{CjwE.M QQ:2987619807 Z*nC
;5Kd
|