-
UID:317649
-
- 注册时间2020-06-19
- 最后登录2025-04-02
- 在线时间1761小时
-
-
访问TA的空间加好友用道具
|
简介 2B`#c}PP O;m@fS2%3 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。 d&apu{ QxS=W2iN 模型 6-!U\R2Z> =}^J6+TVL 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。 w/UZ6fu #Rx|oSc} Table 1. AZ眼睛模型的定义 <-rw>, 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. *Z:'jV< n,vs(ZL: 光源 QnN cGH _oBJ'8R\ 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。 IyJHKDFk e_Un:r@) m2h@* 图1. 光源和提示信息使用 &8R!`uh1 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。 .lE7v -e TOC2[mc' 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。 ^p}|""\j /.>8e%) 图2. 字母F光源的设定方法光 lwj,8 G>>TB{} 图3. 字母F在视网膜上位置点列图 `%oJa` 视网膜的散射 e|2@z-Sp- ~+OAAkJ9 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。 ZA {T0: \Jy/
a- b`yb{&
,? 图4. 视网膜朗伯散射设定 'wm :Xa 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。 `j)S7KN vn"+x_ >A_:qyGk 图5. 视网膜重点采样规格设定 f:hsE 脚本 Al-;-t#Dc pS6p}S=1] 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: yDe6f(D %3;vDB*L$ 图6. 用户对话框的创建与编辑 D6L5X/# 图7. 用户对话框编辑器 r=74'g 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。 E8LA+dKN: 余下的脚本计算与屈光度有关的所有参数。 vj,OX~| R.'-jvO 分析 aTL u7C\-e ZlG|U]mM5 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 Q!*}^W rU!QXg]uD 图7. 字母F在视网膜上颜色分析 ta+MH, 脚本代码 ~4^~w#R 734f&2 Option Explicit 'Remove this to enable non-dimensioned variables to be used. ?_V&~?r b<bj5m4fz> Dim entity As T_ENTITY T0TgV Dim op As T_OPERATION orON)Sks Dim mat As T_MODELMATERIAL PXrv2q[5? Dim A As Double #Ex NiFZ Dim pupilDiam As Double :f_fp(T Dim eID As Long hb="J349 Dim parID As Long #X t|"Z Dim count As Integer w]O[{3" Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double "&Rt&S Dim tlens As Double, nlens As Double sFbN)Cx Dim curv As Double, conic As Double scQnL'\ Dim ok As Long ?%A9}"q] kWMz;{I5*w Sub Main SPN5H;{[]K [L ?^+p> '用户输入对话框 n4sO#p)' Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 uEui{_2$ TextBox 220,21,40,21,.TextBox1 'default: 0 H~:EPFi.( Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 a${<~M
hm OKButton 40,91,90,21 slTE. CancelButton 190,91,90,21 e%_J
O7 Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 'B\7P*L"p TextBox 220,49,40,21,.TextBox2 'default: 4 Q&]f9j_ End Dialog |5TzRz Dim dlg As UserDialog G$mAyK: [JVEKc ym ok = Dialog (dlg) L.?QZN%cN ~J:]cy)Q If ok=0 Then 'cancel button was pressed cXod43 Print "Execution cancelled." F87/p End ItD&L
)) End If CC
B' 1Eh6ti 'Assign accommodation and pupil diameter & use defaults if field left empty (Cb;=:3G If dlg.TextBox1 = "" Then MSaOFv_Q A = 0 'Default accommodation nq5qUErew Else JnIE6@g<y A = CDbl(dlg.TextBox1) ^_gH}~l+U End If XY^]nm-{I .]w=+~h If dlg.TextBox2 = "" Then Qg]+&8!* pupilDiam = 4 'Default pupil diameter p|+TgOYOc Else 0,whTnH| pupilDiam = CDbl(dlg.TextBox2) \,S4-~(:! End If 6,cJ3~!48 Ef$a&*)PH Print " " g{^~g Print "Accommodation = " & A & " Diopters" )uu(I5St Print "Pupil Diameter = " & pupilDiam & " mm" =}g-N)^ 74r$)\q ' Calculate new parameters with accommodation r yNe=9p taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness HtV8=.^ |*$0~mA Rant = 12.0 - 0.4*A 'Radius of anterior lens FBxg^g%PB@ CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens B~B, L*kC2 ezb*tN! Rpost = -5.224557 + 0.2*A 'Radius of posterior lens 3Fw7q" CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens MY}/h@ |Iknk, tlens = 3.767 + 0.04*A 'Lens thickness Cto>~pV GTM@9^ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction rf+Z0C0WYi hg2Ywzfm- 'Adjust parameters to account for accommodation 8]mRX~ hof>:Rk '************************************************************************* !dq$qUl/ 'Aqueous thickness (Position of Lens) a<J<Oc! '************************************************************************* ^8KxU eID = FindFullName( "Geometry.Arizona Eye.Lens" ) <JIqkGeAi GetCustomElement eID, entity I?RUVs d uP0US parID = FindFullName( "Geometry.Arizona Eye" ) ,BFw-A fV2w &:^3 ' Delete any shift(s) in z RzU9]e count = 0 _(-i46x} While GetOperationCount(eID)>count ,xg-H6Xfa{ GetOperation eID, count, op xR8y"CpE If op.Type="ShiftZ" Then {n&GZG"f DeleteOperation eID,count x_ t$* count=count-1 ZUD{V End If ~)F_FS count=count+1 rJh$>V+ ' Wend 6"?#E[ #[ g/(BV7V 'Set new shift in 5=\^DeM@
H op.Type = "ShiftZ" WcQkeh3n op.val1 = taq 8"TlWHF` op.parent = parID 4V c``Um AddOperation eID, op P%ThW9^vnj Print "Set aqueous humor thickness = " & taq-0.55 Jd~M q9( &dPUd~&EL '************************************************************************* I@5$ <SN 'Radius and conic constant of anterior lens 1]9l
SE!E7 '************************************************************************* bI^F( eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) cc3/XBo GetConic eID, entity, curv, conic BNe>Lk o TqSjL{l% SetConic eID, entity, 1/Rant, CCant 5`@yX[G Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /;vHAtt;f b6xz\zCL '************************************************************************* cY Qm8TR< 'Radius and conic constant of posterior lens v_WF.sb~ '************************************************************************* EEMRy eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @-Y,9mM GetConic eID, entity, curv, conic re,}}' zK I1 SetConic eID, entity, 1/Rpost, CCpost R#i`H(N Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost bN6i *)} tt
CC]
Q '************************************************************************* O \gVB!x 'Lens thickness (Position of posterior lens surface) ;VE KrVD '************************************************************************* scTt53v^ *CbV/j"P? parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;.<HpDfG_ rxs:)# ?A ' Delete any z-shift(s) R\Ckk;<$ count = 0 u{w,y.l1h While GetOperationCount(eID)>count #2lvRJB GetOperation eID, count, op E^A!k=> If op.Type="ShiftZ" Then ]826k pq_ DeleteOperation eID,count G*,7pc count=count-1 ef!f4u\ End If aK]AhOG count=count+1 4CtWEq Wend |lk:(~DM Jw>na _FJ 'Set new z-shift m>3\1`ZF~< op.Type = "ShiftZ" :6Tv4ZUvcG op.val1 = tlens So75h*e op.parent = parID u#`51Hr$ AddOperation eID, op KV-h~C Print "Set lens thickness = " & tlens 6'x3g2C/ ^N7 C/" p '************************************************************************* O4:_c-V2 'Lens index of refraction :Rnwyj]) '************************************************************************* ic4hO>p& eID = FindMaterial( "Lens" ) zD<8.AIGC GetModelMaterial eID, mat ];5Auh0o r:Q=6j, mat.Nd = nlens B9Wd
' SetModelMaterial eID, mat G'';VoW= Print "Set lens index of refraction = " & nlens I~Qi):&x
w~jm0jK] '************************************************************************* LU8:]zOY 'Pupil diameter Ct zWdo. '************************************************************************* +\u\BJ!LAJ eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) FQE(qltf, pSEaE9AX% 'Adjust pupil diameter (trimming volume inner hole) DO9K o}f$?{)| SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }W(t>> O(9*VoD ' Adjust pupil location to just in front of the lens NB86+2stu parID = FindFullName( "Geometry.Arizona Eye" ) lDF7~N9J_ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) rhX?\_7o count = 0 :7 JP(j2 While GetOperationCount(eID)>count PfB9 .f{ GetOperation eID, count, op 94]i|2qj* If op.Type="ShiftZ" Then U.b|3E/^ DeleteOperation eID,count *UXa.kT@ count=count-1 Fey^hx
w = End If jGo\_O<of count=count+1 /[ft{:#&t Wend
;O5Iu op.Type = "ShiftZ" &3xda1H op.val1 = taq-0.01 jxt]Z3a ~0 op.parent = parID <b\8<mTr AddOperation eID, op .2_xTt f^F"e'1 Print "Set pupil diameter = " & pupilDiam (H:A|Lw 84i0h$ZZo 'Update AZ Eye subassembly Description 4L4u< eID = FindFullName( "Geometry.Arizona Eye" ) =W2I0nr. GetEntity eID, entity hd[t&?{= entity.Description = "Accommodation = " & A & "D" wlslG^^(! SetEntity eID, entity I3i zLi Fpwhyls Update Nez '1 Print "DONE!" _JA)""l% ^gNbcWc7CU End Sub 0]$-}AYM -/*VR$c 如果屈光度是4,光瞳直径是4,则会输出如下数据: g:U
-kK!i SJ:Teab Accommodation = 4 Diopters sJl>evw Pupil Diameter = 4 mm )7Qp9Fxo Set aqueous humor thickness = 2.81 C@-cLk Set anterior lens radius = 10.4 and conic constant = -2.375869 b^()[4M; Set posterior lens radius = -4.424557 and conic constant = -3.081019 yJlRW!@&: Set lens thickness = 3.927 )KkV< |