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2022-02-25 09:52 |
Arizona眼睛模型
简介 }tuC} I{&[[7H 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。 uMv,zO5 8d{0rqwNE 模型 O\tb R= T<>,lQs(a 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。 M0"_^? Table 1. AZ眼睛模型的定义 [attachment=111140] zI uJ-8T" "{xrL4BtC 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. RBd7YWo\|j n&/
` 光源 VGN5<?PrN Ee#q9Cx^J 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。 W*:.Gxv] Z\rwO>3 [attachment=111141] 图1. 光源和提示信息使用 Vp\,CuQ `(;m?<% 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。 gVuFHHeUz 2[yd> (` 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。 t}4,]ms [attachment=111142] 图2. 字母F光源的设定方法光 {S\{Ii6 DCa^
u'f [attachment=111143] 图3. 字母F在视网膜上位置点列图 = svN#q5s Ix}sK"}[n 视网膜的散射 7A7?GDW JR|ck=tq 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。 372rbY N~gzDQ3 [attachment=111144] 图4. 视网膜朗伯散射设定 v1JzP# t?gic9
q 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。 r5/0u(\LB 29b9`NXt [attachment=111145] 图5. 视网膜重点采样规格设定 9FR5Jw>t gJ{)-\ 脚本 6MW{,N OT*mO&Z 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: J;e2&gB [attachment=111146] 图6. 用户对话框的创建与编辑 i]4I [! [attachment=111147] 图7. 用户对话框编辑器 gD?l-RT> "k@/3 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。 z<;HQX, 余下的脚本计算与屈光度有关的所有参数。 j$:~Rek JbbzV> 分析 $%Kfq[Q xo&_bMO 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 e*C(q~PQ [attachment=111148] 图7. 字母F在视网膜上颜色分析 #!#
l45p6 `wVyb>T 脚本代码 '<<t]kK[N {P./==^0
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. jr."I+
'H!Uh]! Dim entity As T_ENTITY am'7uy!ka~ Dim op As T_OPERATION /~?*=}c^m Dim mat As T_MODELMATERIAL )akoa,#%6c Dim A As Double m(!FHPvN Dim pupilDiam As Double j^JPZ{ej? Dim eID As Long t*u:hex Dim parID As Long * u>\57W Dim count As Integer \8cx6 G' Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double AkV#J,
3LC Dim tlens As Double, nlens As Double vE?G7%, Dim curv As Double, conic As Double >GRxHK@G Dim ok As Long 6{b>p+U n>YKa)|W` Sub Main `^&OF uee }Y\%RA '用户输入对话框 Y3b *a".X Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 @9s$4DS TextBox 220,21,40,21,.TextBox1 'default: 0 D,feF9 Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 7:1Lol-V OKButton 40,91,90,21 jLluj CancelButton 190,91,90,21 HZge!Yp< Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Rm( "=( TextBox 220,49,40,21,.TextBox2 'default: 4 &8lZNv8;(p End Dialog l_p2Riv Dim dlg As UserDialog i_%_ x* o+'6`g'8 ok = Dialog (dlg) rILYI;'o Gc|idjW4 If ok=0 Then 'cancel button was pressed 02^ rV*re Print "Execution cancelled." 4r}51 N\ End (9a^$C* End If @ 6vIap| e^voW"?% 'Assign accommodation and pupil diameter & use defaults if field left empty {IjR^J=k If dlg.TextBox1 = "" Then PW0LG^xp` A = 0 'Default accommodation !a\^Sk
/ Else 2,b$7xaf A = CDbl(dlg.TextBox1) B+`g>h End If 6gDN`e,@ *.[.
{qG( If dlg.TextBox2 = "" Then h*\%vr pupilDiam = 4 'Default pupil diameter Pq$n5fZC! Else jP.dDYc pupilDiam = CDbl(dlg.TextBox2) "tK=+f`NM End If %|oym.-I6
f o3}W^0 Print " " ~}
~4 Print "Accommodation = " & A & " Diopters" P%n>Tg80M Print "Pupil Diameter = " & pupilDiam & " mm" $`8wJf9@w tH4B:Bgj! ' Calculate new parameters with accommodation Lg hfM"g taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness %hP^%'G 2=}FBA,2 Rant = 12.0 - 0.4*A 'Radius of anterior lens fz_r7? CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens o8MZiU1Xf BgT*icd8d Rpost = -5.224557 + 0.2*A 'Radius of posterior lens UiNP3TJ'L CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens :`sUt1Fw. -{vD:Il=6 tlens = 3.767 + 0.04*A 'Lens thickness lOp`m8_= (9)Q ' 'S nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction uY*L,j^) "dlVk~ 'Adjust parameters to account for accommodation WIGi51yC.x K
8O|?x] '************************************************************************* #dHa,HUk 'Aqueous thickness (Position of Lens) eMzk3eOJ '************************************************************************* !,PWb3S eID = FindFullName( "Geometry.Arizona Eye.Lens" ) XWw804ir GetCustomElement eID, entity n6v6K1 lTsjxw
o parID = FindFullName( "Geometry.Arizona Eye" ) %so]L+r2! ?JUeuNs9 ' Delete any shift(s) in z mE[y SrV count = 0 O/LXdz0B While GetOperationCount(eID)>count eS!/(#T GetOperation eID, count, op ssL\g`xe If op.Type="ShiftZ" Then :Dp0?&_ DeleteOperation eID,count w-jVC^C] count=count-1 [F7hu7zY8 End If Ys7]B9/1O count=count+1 ?7A>+EY Wend X>^fEQq" PvL[e"p 'Set new shift in 2 E=L8< op.Type = "ShiftZ" 4M T 7 `sr op.val1 = taq /wv0i3_e
op.parent = parID 7 8,n%=nG AddOperation eID, op gGuO Print "Set aqueous humor thickness = " & taq-0.55 jiGTA:v y7<|_:00 '************************************************************************* /{2,zW 'Radius and conic constant of anterior lens OTv) '************************************************************************* JGZBL{8 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) zm# ?W GetConic eID, entity, curv, conic SrJE_~i n{jGOfc SetConic eID, entity, 1/Rant, CCant /_.|E] Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant <ZW-QN4 H/Jbk*Q '************************************************************************* *^r}"in 'Radius and conic constant of posterior lens }B^tL$k '************************************************************************* |BYRe1l6l eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @9:uqsL GetConic eID, entity, curv, conic O&&~NXI\ kf9X$d6 SetConic eID, entity, 1/Rpost, CCpost y>LBl] Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =|9!vzG4 &3&HY:yF '************************************************************************* F[MFx^sT{ 'Lens thickness (Position of posterior lens surface) YZ7.1`8 '************************************************************************* #;S*V" p}P-6&k,U parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ABkl%m6xf ipz5 H* ' Delete any z-shift(s) _Ey5n!0: count = 0 [B3RfCV{ While GetOperationCount(eID)>count ^sZ,2,^ GetOperation eID, count, op [Qr"cR^ If op.Type="ShiftZ" Then ,,TnIouy DeleteOperation eID,count 31)&vf[[ count=count-1 JS77M-Ac End If t,'<gI count=count+1 TZ`SZDc7_ Wend JI5Dy>u: s^SJY{ 'Set new z-shift pot~<d`:K" op.Type = "ShiftZ" (.,G=\! op.val1 = tlens `X8F`5&U\f op.parent = parID w
= KPT''! AddOperation eID, op mc3"`+o Print "Set lens thickness = " & tlens 4P0}+ 0YHFvy) '************************************************************************* 2pAW9R#UV- 'Lens index of refraction W!<U85-#S '************************************************************************* PW4q~rc=: eID = FindMaterial( "Lens" ) ;d?R:Uw8 GetModelMaterial eID, mat G&dKY h\ W9)&!&<o mat.Nd = nlens H.0K?N&\?> SetModelMaterial eID, mat ?#fQ~ s Print "Set lens index of refraction = " & nlens n:X y6H KmF]\:sMD '************************************************************************* cnLro 'Pupil diameter oU/5 a>9~ '************************************************************************* tVjsRnb{ eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) d'2A,B~_* (w{j6).3Dj 'Adjust pupil diameter (trimming volume inner hole) YK\X+"lB qWw=8Bq SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" wS*E(IAl p#Bi>/C6 ' Adjust pupil location to just in front of the lens OKV8zO parID = FindFullName( "Geometry.Arizona Eye" ) ;\]@K6m/Ap eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #1[u(<AS count = 0 Je{ykL?N While GetOperationCount(eID)>count q:(%*sY> GetOperation eID, count, op 4m)n+ll If op.Type="ShiftZ" Then W4N{S.#! DeleteOperation eID,count u&NV,6Fj2[ count=count-1 B1STG L`nK End If h\e.e3/ count=count+1 $u.z*b_yy Wend 1"g<0
W op.Type = "ShiftZ" iB{V^ksU op.val1 = taq-0.01 AR=]=8 op.parent = parID $C\BcKlmv AddOperation eID, op ZW}_DT0 5m*,8 ]!- Print "Set pupil diameter = " & pupilDiam ys~x$ ise-O1' 'Update AZ Eye subassembly Description +0~YP*I`/ eID = FindFullName( "Geometry.Arizona Eye" ) HhpDR GetEntity eID, entity JO;Uus{? entity.Description = "Accommodation = " & A & "D" /NlGFO*Z SetEntity eID, entity /\Ef%@ Z7#+pPt! Update
$k?>DP4 Print "DONE!" ,'+kBZOv ]A"h&`Cvt End Sub G#CXs:1pd+ NgwbQ7) 如果屈光度是4,光瞳直径是4,则会输出如下数据: *Uh!>Iv;
(=$x.1 Accommodation = 4 Diopters G"6 !{4g Pupil Diameter = 4 mm zTp"AuNHN Set aqueous humor thickness = 2.81 /,dz@ Set anterior lens radius = 10.4 and conic constant = -2.375869 +%&yJ4- Set posterior lens radius = -4.424557 and conic constant = -3.081019 yr6V3],Tp Set lens thickness = 3.927 <[phnU^
8 Set lens index of refraction = 1.42672 %$I;{-LD Set pupil diameter = 4 [ }:$yg DONE!
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