infotek |
2021-10-22 09:55 |
Arizona眼睛模型
简介 z5sKV7&\[n k9c`[M 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。 =,08D^ xY }/g1 模型 >R.!Qze\G cCIs~*D 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。 3ZvQUH/{W zP/SDW
Table 1. AZ眼睛模型的定义 k\ZU%"^J 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. -cUw} ^Nysx ~6 光源 5 L-6@@/ 8P&z@E{y 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。 9A}y^=!` P%<MQg|k` {P%\& \{F
图1. 光源和提示信息使用 mk6>}z* 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。 I#W J";kqB lO}I>yo}\ 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。 '47E8PIJ| yPH5/5;,
图2. 字母F光源的设定方法光 /EL3Tt Ihl]"76q/
图3. 字母F在视网膜上位置点列图 Tcq@Q$H 视网膜的散射 &*~_ "WyU /8P7L'Rb 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 u#3Cst8Y ETfoL.d$( xI~ c~KC
图4. 视网膜朗伯散射设定 @X_)%Y-^O 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。 `<%
w4E ZPHatC B<,AI7
图5. 视网膜重点采样规格设定 S^~
lQ|D 脚本 ~sCdvBA 6h\; U5 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: ;]2d%Qt ZrWA,~;
图6. 用户对话框的创建与编辑 Qr~yHFc1y
图7. 用户对话框编辑器 |(9l_e| 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。 :/;;|lGw 余下的脚本计算与屈光度有关的所有参数。 z~;@Mo"*f Angt=q 分析 Ystd[ .?r}3Ch 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 B>
zQ[e@t ?C_Y2JY
图7. 字母F在视网膜上颜色分析 59(} D'lw> 脚本代码 @$?*UI6y Kq:vTz&< Option Explicit 'Remove this to enable non-dimensioned variables to be used. 7#9fcfL '^.3}N{Fo Dim entity As T_ENTITY *(nu0 Dim op As T_OPERATION CbT ;#0 Dim mat As T_MODELMATERIAL s18A Dim A As Double 1xsB@D Dim pupilDiam As Double |PLWF[+t8 Dim eID As Long TZ PUVOtL_ Dim parID As Long #LG<o3An Dim count As Integer A)nE+ec1 Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ymA8`k5>@ Dim tlens As Double, nlens As Double qkq^oHI Dim curv As Double, conic As Double /qXP\ a Dim ok As Long t},71Ry <z{,@Z} Sub Main R78lV-};Q 3:gF4(. '用户输入对话框 jft@ 'W53 Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 f7 zGz TextBox 220,21,40,21,.TextBox1 'default: 0 :Y&h'FGZm Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 (vbI4&r OKButton 40,91,90,21 kJ B u7 CancelButton 190,91,90,21 .vpx@_;]9 Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {uiL91j. TextBox 220,49,40,21,.TextBox2 'default: 4 SCXtBZ`.G End Dialog k
i{8f Dim dlg As UserDialog mB*;> f_> lz ok = Dialog (dlg) \2)~dV:6+ _Ns_$_ If ok=0 Then 'cancel button was pressed '6Yx03t Print "Execution cancelled." g<MCvC@ End
4-q8:5 End If <#7j~ < ~@K!>j 'Assign accommodation and pupil diameter & use defaults if field left empty N`5
mPE If dlg.TextBox1 = "" Then h)
W|~y@ A = 0 'Default accommodation 3F9AnS Else 2r#W#z%vS A = CDbl(dlg.TextBox1) 6 kAXE\T End If ;d||u +v|]RgyW) If dlg.TextBox2 = "" Then /@K1"/fqH pupilDiam = 4 'Default pupil diameter A)u,Hvn Else bH_zWk pupilDiam = CDbl(dlg.TextBox2) Y/G~P,9 End If +L#Q3}=s 6Y}Bza Print " " GP=&S|hi Print "Accommodation = " & A & " Diopters" (hIy31Pf Print "Pupil Diameter = " & pupilDiam & " mm" KoTQc0b! t
x#(K#/ ' Calculate new parameters with accommodation 0I[3%Q { taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness R8fB
8 ) RL1cx| Rant = 12.0 - 0.4*A 'Radius of anterior lens |j7{zsH CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens WB=|Ty~l &13#/ Rpost = -5.224557 + 0.2*A 'Radius of posterior lens nSh}1Arp/ CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens B}Sl1)E O\)rp!i tlens = 3.767 + 0.04*A 'Lens thickness ?-9It|R 3X}>_tj nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction C(5B/W6 |1^
!rHg 'Adjust parameters to account for accommodation 2< Q3-|/i i 9w k) '************************************************************************* ffS]%qa 'Aqueous thickness (Position of Lens) ^Euqy,8} '*************************************************************************
+`Ypc eID = FindFullName( "Geometry.Arizona Eye.Lens" ) MbjMO"} GetCustomElement eID, entity 5<L+T `'M}.q,k~ parID = FindFullName( "Geometry.Arizona Eye" ) |fg{Fpc @j?)uJ0Q ' Delete any shift(s) in z =aE!y5 count = 0 hha^:, While GetOperationCount(eID)>count 0|@*`-:VO GetOperation eID, count, op YCEdt>5PA If op.Type="ShiftZ" Then KcNh3CR DeleteOperation eID,count UqaV9 count=count-1 @b"J FB| End If q~*> count=count+1 Dg2=;)"L Wend #&ZwQw 5t~p99#? 'Set new shift in O%?d0K op.Type = "ShiftZ" <hSrx7o op.val1 = taq DZ~qk+,I op.parent = parID x6={)tj AddOperation eID, op i$!-mYi+Q! Print "Set aqueous humor thickness = " & taq-0.55 ZF6?N?t}h8 .YcI . '************************************************************************* WaYT7 : 'Radius and conic constant of anterior lens Erd)P '************************************************************************* 1lLL9l{UVw eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) j^'op|l GetConic eID, entity, curv, conic }qOj^pkJ *%wfR7G[B SetConic eID, entity, 1/Rant, CCant 9>na3ISh Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant p?,: YFY$iN~B, '************************************************************************* ]K(>r#'nH 'Radius and conic constant of posterior lens (:2,Rr1" '************************************************************************* ^%pM$3ov eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 1rmK#ld"=Z GetConic eID, entity, curv, conic ,/>hWAx `$odxo+ SetConic eID, entity, 1/Rpost, CCpost t^zmvPDK Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost DYKJ Vn7w NWq>Z!x` '************************************************************************* 7$&3(#!N 'Lens thickness (Position of posterior lens surface) O>j_x W]V '************************************************************************* =Vm"2g,aA W{!GL parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %t:pG}A>:C ``p()^zT ' Delete any z-shift(s) UfUboxT count = 0 &hb:~> While GetOperationCount(eID)>count mgxoM|n6 GetOperation eID, count, op {q-<1|xj/J If op.Type="ShiftZ" Then *6trK`tx^ DeleteOperation eID,count xF4>G0 count=count-1 vS{zLXg End If 8I`t`C/4 count=count+1 b=Y:`&o=[ Wend r-];@ :"4Pr/}rT 'Set new z-shift W%xg;uzp op.Type = "ShiftZ" wtY*{m2 op.val1 = tlens 8- U1Y
op.parent = parID }bxW@(bs AddOperation eID, op ]'2;6%.4 Print "Set lens thickness = " & tlens <[eE5X( 30fsVwE2 '************************************************************************* !F_BLHig 'Lens index of refraction 9$u'2TV '************************************************************************* Gx]J6Z8 eID = FindMaterial( "Lens" ) _*SA_.0 GetModelMaterial eID, mat y.l`NTT]< (A\p5@ht mat.Nd = nlens lo%:$2*'p SetModelMaterial eID, mat Gs% cod Print "Set lens index of refraction = " & nlens EN =oA P pS3TD"p '************************************************************************* _'yN4>=6u 'Pupil diameter .9< i '************************************************************************* $~[k?D eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) oP$l( k oTPPYi[r 'Adjust pupil diameter (trimming volume inner hole) 4nfpPNt #Tjv(O[& SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" py9HUyr5eZ $:#{Y;d ' Adjust pupil location to just in front of the lens `Eijy3>h parID = FindFullName( "Geometry.Arizona Eye" ) e*7nq~ B5 eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) &3SQVOW ~T count = 0 u7oHqo` While GetOperationCount(eID)>count b0A*zQA_) GetOperation eID, count, op ]5+db0 If op.Type="ShiftZ" Then Jv|uI1V DeleteOperation eID,count Iq@: n_~ count=count-1 "t-u=aDl-. End If B} %B4&Ij count=count+1 nty^De% Wend H WOl79- op.Type = "ShiftZ" &:i|;^^2 op.val1 = taq-0.01 '8Q:}{ op.parent = parID f
xWW"B*A AddOperation eID, op _k0X)N+li Q]Ymv:M, Print "Set pupil diameter = " & pupilDiam iBq|] RJo"yB$1e6 'Update AZ Eye subassembly Description ^r u1QDT eID = FindFullName( "Geometry.Arizona Eye" ) u*I=. GetEntity eID, entity :
"|M entity.Description = "Accommodation = " & A & "D" rNgFsFQ>. SetEntity eID, entity D5wy7`c z$VA]tI( Update VOkEDH Print "DONE!" |a(%a43fC TTS.wBpR, End Sub s&<6{AU(id D;pfogK @ 如果屈光度是4,光瞳直径是4,则会输出如下数据: ^^u{W|'CaH -'j_JJ Accommodation = 4 Diopters :N \j@yJK Pupil Diameter = 4 mm ewNzRH,b Set aqueous humor thickness = 2.81 l(EDe Set anterior lens radius = 10.4 and conic constant = -2.375869 "k)}qI{ Set posterior lens radius = -4.424557 and conic constant = -3.081019 @WV}VKm Set lens thickness = 3.927 mVg$z Set lens index of refraction = 1.42672 N3D{t\hg Set pupil diameter = 4 Sn I-dXNF DONE! MeXzWLH
|
|