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2022-02-25 09:52 |
Arizona眼睛模型
简介 zp\8_ U@ >U F 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。 5T sU Qc 720PjQ 模型 C{TA.\ J>fQNW!{ 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。 ?X@fKAj Table 1. AZ眼睛模型的定义 [attachment=111140] ;&H4u) h(WrL 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. 2,ECYie^ YK|bXSA[ 光源 ^u3V
E G\|,5HED 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。 8XbA'% o 74!oe u.> [attachment=111141] 图1. 光源和提示信息使用 LYlDc;<A /cc\fw1+ 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。 >S$Z gV&z2S~" 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。 .<kqJ|SVi [attachment=111142] 图2. 字母F光源的设定方法光 F~A 'X \u6^Varw [attachment=111143] 图3. 字母F在视网膜上位置点列图 f~ }H ySI~{YVM 视网膜的散射 >0Q|nCx ^CwR!I.D}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。 %Uz(Vd#K R|i/lEq [attachment=111144] 图4. 视网膜朗伯散射设定 C8F 7bG8c kdGT{2u 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。 s-dLZ.9F 'X shmZ0& [attachment=111145] 图5. 视网膜重点采样规格设定 !^Q.VYY &89oO@5 脚本 '\jd#Kn'h l<M'=-Y 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: mKYeD%Pm* [attachment=111146] 图6. 用户对话框的创建与编辑 r|,i'T [attachment=111147] 图7. 用户对话框编辑器 IIy~[4dW ?-1r$31p 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 YM5fyv? 余下的脚本计算与屈光度有关的所有参数。 :;t
#\%L/ sXNb }gJ 分析 610D%F =]k {"?j 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 |!y A@y? [attachment=111148] 图7. 字母F在视网膜上颜色分析 !UFfsNiXZ z0/}
! 脚本代码 :d ~|jS %vBhLaE
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. `5H$IP1XhA
Wh&8pH: Dim entity As T_ENTITY 2)j0Ai% Dim op As T_OPERATION 9{:O{nl Dim mat As T_MODELMATERIAL \W%UZs Dim A As Double NH3cq Dim pupilDiam As Double NV#FvM/#" Dim eID As Long qc-mGmom L Dim parID As Long IgC}& Dim count As Integer cV`E>w=D0 Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double -,["c9'3 Dim tlens As Double, nlens As Double j;+?HbL Dim curv As Double, conic As Double Un6/e/6, Dim ok As Long =|=.>?t6Z0 n`4K4y%Dy} Sub Main j)
,,"54* r7Ya\0gU '用户输入对话框 Oh4AsOj@ Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $ Y 7c TextBox 220,21,40,21,.TextBox1 'default: 0 c2K:FdB Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 'g9"Qv?0{` OKButton 40,91,90,21 S(7ro]U9 CancelButton 190,91,90,21 z)uuxNv[R Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 !Kv@\4 TextBox 220,49,40,21,.TextBox2 'default: 4 BATG FS& End Dialog \%p34K\ Dim dlg As UserDialog aH#l9kCb d[;.r ok = Dialog (dlg) p6vKoI#T N~F
RM& x If ok=0 Then 'cancel button was pressed B*E2.\~ Print "Execution cancelled." iPrLwheb End YZ+RWu9K End If mq%<6/YU B4]`-mahO 'Assign accommodation and pupil diameter & use defaults if field left empty SRSvot};C If dlg.TextBox1 = "" Then `l*;t`h A = 0 'Default accommodation <r3J0)r} Else 1@lJonlF A = CDbl(dlg.TextBox1) y_.!!@, End If pT$f8xJ oP4GEr If dlg.TextBox2 = "" Then "kc/J*u-3 pupilDiam = 4 'Default pupil diameter uB7 V?A Else K5"#~\D pupilDiam = CDbl(dlg.TextBox2) M5x U9]B End If 1 1cWy+8D ;.bm6(; Print " " ,()0'h}n Print "Accommodation = " & A & " Diopters" ?h1H.s2X Print "Pupil Diameter = " & pupilDiam & " mm" 7-BvFEM; ]@Sj`J[fd ' Calculate new parameters with accommodation f#Xyoa% taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness G-T0f 'fL"txW Rant = 12.0 - 0.4*A 'Radius of anterior lens "al`$ %( CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens 4np qJ1 EJ`T$JD Rpost = -5.224557 + 0.2*A 'Radius of posterior lens U#1bp}y CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens CNww`PX,zZ X*L;.@xA tlens = 3.767 + 0.04*A 'Lens thickness F!.E5<&7= ^#0U ?9 nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction HQ{JwW!m "5A&_E }3
'Adjust parameters to account for accommodation 03j]d&P%d
wK}\_2? '************************************************************************* S'HnBn / 'Aqueous thickness (Position of Lens) CwJDmz\tk '************************************************************************* OnWx#84 eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 95<EN(oUD GetCustomElement eID, entity *~/OOH$" LjU'z# parID = FindFullName( "Geometry.Arizona Eye" ) .Udj@{ ?i`l[+G ' Delete any shift(s) in z _Ob@` count = 0 1[]&(Pa While GetOperationCount(eID)>count FCkf# GetOperation eID, count, op A0%}v* If op.Type="ShiftZ" Then &)oOeRwi]. DeleteOperation eID,count \RVW count=count-1 +<prgP`v End If !a~`Bs$'jr count=count+1 rcGb[=B f Wend !cGDy/| {3!E4"p 'Set new shift in 4ikd M/ op.Type = "ShiftZ" RyRpl*^ op.val1 = taq hb{u'= op.parent = parID YSaJeU>@ AddOperation eID, op #Mg]GeDJ{ Print "Set aqueous humor thickness = " & taq-0.55 MaD3[4@# SwU\
q]^|Z '************************************************************************* 7$rjlVe 'Radius and conic constant of anterior lens .I@CS>j '************************************************************************* 3~#h|? eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) *9p |HX= GetConic eID, entity, curv, conic 7n90f2"m .IJ_jt-^d SetConic eID, entity, 1/Rant, CCant n$[f94d= Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant @x/T&67k S\CRG> '************************************************************************* (Y^X0yA/ 'Radius and conic constant of posterior lens IL_d:HF|1 '************************************************************************* ~y$ !48o eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) F,5r9^,_ GetConic eID, entity, curv, conic 0<TD/1wN ;}z\i SetConic eID, entity, 1/Rpost, CCpost -8N|xQ378 Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost r_YIpnJ Yhp]x '************************************************************************* %okzOKKX 'Lens thickness (Position of posterior lens surface) rDdzxrKg{ '************************************************************************* +ht|N[P +-B^Z On parID = FindFullName( "Geometry.Arizona Eye.Lens" ) e:AHVepj{ >]%8Zx[ ' Delete any z-shift(s) <[GYLN[0Q count = 0 LB/C-n.` While GetOperationCount(eID)>count ?`[NFqv_] GetOperation eID, count, op Bb{!Yh].:A If op.Type="ShiftZ" Then @/&b;s73 DeleteOperation eID,count % },Pe count=count-1 it2 a End If J1XL<7 count=count+1 Eq:2k)BE Wend G4
G5PXi @t1V
o}c 'Set new z-shift OUP?p@%]< op.Type = "ShiftZ" +PK6-c\r op.val1 = tlens 8z5# ]u; op.parent = parID "g+z !4b# AddOperation eID, op FecktD= Print "Set lens thickness = " & tlens ^h&I H| iBudmT8 '************************************************************************* xug)aE 'Lens index of refraction pG"5!42M! '************************************************************************* ?r_l8 eID = FindMaterial( "Lens" ) :D7|%KK GetModelMaterial eID, mat t4K~cK 9%sM*[A mat.Nd = nlens +%\oO/4Fs SetModelMaterial eID, mat H.G!A6bd Print "Set lens index of refraction = " & nlens F\ctu aLC O--7<Q\ '************************************************************************* V,EF'-F 'Pupil diameter wve=.n '************************************************************************* I?Q+9Rmm`J eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ^zEE6i Q)af|GW$ 'Adjust pupil diameter (trimming volume inner hole) tZ2e!<C 2AVc?
9@ SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ^/Sh=4=G j<"nO( ' Adjust pupil location to just in front of the lens <5@PWrU?[[ parID = FindFullName( "Geometry.Arizona Eye" ) ^6p'YYj"5 eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Tp<k<uKD count = 0 >5T_g2pkv While GetOperationCount(eID)>count `:M^8SYrL GetOperation eID, count, op TFDm5XJ If op.Type="ShiftZ" Then &@ 3m-Z DeleteOperation eID,count *R% wUi count=count-1 6k?`:QK/sl End If 6aOp[-Le count=count+1 N]5m(@h
Wend _x1EZ&dh op.Type = "ShiftZ" \.e4.[%[2- op.val1 = taq-0.01 G[idN3+# op.parent = parID R|!B,b( AddOperation eID, op VSOz.g> ZkB3[$4C=5 Print "Set pupil diameter = " & pupilDiam ^+?|Qfi c#xP91.m 'Update AZ Eye subassembly Description cjULX+h eID = FindFullName( "Geometry.Arizona Eye" ) d`Q7"}uZ GetEntity eID, entity }g f}eH entity.Description = "Accommodation = " & A & "D" (foBp SetEntity eID, entity =FW5Tkw0 :46h+?
Update /48 =UK Print "DONE!" e<gx~N9l' AH{^spD{7, End Sub PI5j"u UO k5+]SG`]] 如果屈光度是4,光瞳直径是4,则会输出如下数据: wX1ig '4;6u]d)2 Accommodation = 4 Diopters Uz8hANN0_ Pupil Diameter = 4 mm Tvf~P w Set aqueous humor thickness = 2.81 6!EYrX}rI[ Set anterior lens radius = 10.4 and conic constant = -2.375869 FuP/tTMU1a Set posterior lens radius = -4.424557 and conic constant = -3.081019 INMP"1 Set lens thickness = 3.927 w\|Ei( Set lens index of refraction = 1.42672 3/M.0}e Set pupil diameter = 4 B94
&elu DONE!
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