| infotek |
2022-02-25 09:52 |
Arizona眼睛模型
简介 ~Wf&$p<| |^8l8u 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。 &0+;E-_ ggXg4~WL 模型 o.*8$$ Y Dq5%N` 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。 OpW4@le_r Table 1. AZ眼睛模型的定义 [attachment=111140] 9jCn|+ )Gh"(]-< 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. mi`!'If0) )C|[j@MD 光源 &k+jVymH /YKg.DA| 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。 ZQlja >\+c@o[ [attachment=111141] 图1. 光源和提示信息使用 h;u8{t" >;-.rJFr 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。 #/=s74.b
rF'_YYpr> 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。 S8(Y+jgk;a [attachment=111142] 图2. 字母F光源的设定方法光 |:7O (P%{Tab [attachment=111143] 图3. 字母F在视网膜上位置点列图 1MkQ$v7m omisfu_~E 视网膜的散射 F%Oy4*4 4! ]28[2B6 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。 Ro\ U T64 f*)8bZDD [attachment=111144] 图4. 视网膜朗伯散射设定 [Q9#44@{S; DyhW_PH2J 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。 (1Q G]1q 0'j/ 9vm [attachment=111145] 图5. 视网膜重点采样规格设定 sl?> X)} 1-JdQs6 脚本 oMey^]! b/"&E'5-`\ 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: >d2U=Yk! [attachment=111146] 图6. 用户对话框的创建与编辑 `#J0@ - [attachment=111147] 图7. 用户对话框编辑器 b`:n i
($s%5| 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。 gkkT<hEV= 余下的脚本计算与屈光度有关的所有参数。 pe%$(%@v 9=RfGx 分析 qrdA4S iwM$U(
9 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 :]]#X
~J [attachment=111148] 图7. 字母F在视网膜上颜色分析 "wqN,}bj\ 0o-.m 脚本代码 K3g<NC
yn`P:[v
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. 9pF@#A9p
#M/^n0E Dim entity As T_ENTITY ^\"@r%| Dim op As T_OPERATION }Zuk}Og9+ Dim mat As T_MODELMATERIAL k4i*80 Dim A As Double $tm%=g^ Dim pupilDiam As Double fGtYvl O-5 Dim eID As Long rm}%C(C{J Dim parID As Long (D5sJ$&E@\ Dim count As Integer MJ.K,e Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double qp##>c31X Dim tlens As Double, nlens As Double .dwy+BzS Dim curv As Double, conic As Double =%=lq0GF0 Dim ok As Long `xXpP"*o} ahoXQ8c:\} Sub Main NB^+Hcb$ _/c1b>kcso '用户输入对话框 #lDW? Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 '73g~T%$^* TextBox 220,21,40,21,.TextBox1 'default: 0 qdCcMcGt Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 _GbwyfA
n# OKButton 40,91,90,21 (/ qOY CancelButton 190,91,90,21 Gv(?u Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 3xX^pjk TextBox 220,49,40,21,.TextBox2 'default: 4 t@vVE{` End Dialog ^!v{
>3 Dim dlg As UserDialog m+!T
$$W ?h|&kRq ok = Dialog (dlg) p!Xn iY - _?U/k(Hi If ok=0 Then 'cancel button was pressed I6e[K(7NY Print "Execution cancelled." UTS.o#d End PP-U. End If /?Y]wY Fm#`}K_ 'Assign accommodation and pupil diameter & use defaults if field left empty ^B?brH} If dlg.TextBox1 = "" Then 4K(oOxc9. A = 0 'Default accommodation =nff;Xu Else =kP|TR!o- A = CDbl(dlg.TextBox1) L/c`t7 End If uA[c$tBe 8= "01 If dlg.TextBox2 = "" Then Ly P Cc| pupilDiam = 4 'Default pupil diameter %'w?fqk Else 5"9'=LV~ pupilDiam = CDbl(dlg.TextBox2) +mRc8 G End If SVn $!t =/e$Rp Print " " ,(3oAj\ Print "Accommodation = " & A & " Diopters" mW=9WV Print "Pupil Diameter = " & pupilDiam & " mm" 6an= C_Mb` 7e:eL5f>~ ' Calculate new parameters with accommodation ]4onY> taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness QV[#^1 j8)rz Rant = 12.0 - 0.4*A 'Radius of anterior lens yu}yON CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens 1]a\uq} `-w, 6 Rpost = -5.224557 + 0.2*A 'Radius of posterior lens ]@!3os,CNF CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens BG8`B'i \SN>Yy tlens = 3.767 + 0.04*A 'Lens thickness _BoYyJQH &Jd_@F#J nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction H X{K5 + f^)iv
]p 'Adjust parameters to account for accommodation 9@8'*a{`m }g&
KT!r '************************************************************************* u7SC_3R 'Aqueous thickness (Position of Lens) !u;gGgQF '************************************************************************* f#McTC3C eID = FindFullName( "Geometry.Arizona Eye.Lens" ) sIMN""@Y^ GetCustomElement eID, entity >8|V[-H I9e3-2THfj parID = FindFullName( "Geometry.Arizona Eye" ) Dy*K;e-+ #&b<D2d ' Delete any shift(s) in z R*?!xDJ count = 0 %~:@}C%A While GetOperationCount(eID)>count nlZJ}xZ GetOperation eID, count, op |\xTcS|d If op.Type="ShiftZ" Then .X5A7 m DeleteOperation eID,count ,$Cr9R&/ count=count-1 "xNP"S End If hW9U%-D count=count+1 .Fx3WryF Wend CzIs_/ FOhq&\nkU 'Set new shift in ?zf3AZ9 op.Type = "ShiftZ" ?Yx2q_KZk op.val1 = taq ??P%. op.parent = parID X3][C AddOperation eID, op gtIEpYN+ Print "Set aqueous humor thickness = " & taq-0.55 P@Fx6 BY9Z}/{j '************************************************************************* !K+hXQE1 'Radius and conic constant of anterior lens u08j9)
,4 '************************************************************************* #guK&?Fye eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) E@6gTx* GetConic eID, entity, curv, conic A
H=%6oT2 ^Nu j/ SetConic eID, entity, 1/Rant, CCant hgbf"J6V8 Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant +_25E.>ml 1Y%lt5,* '************************************************************************* hi4-Z=pl 'Radius and conic constant of posterior lens @
'c(q=K; '************************************************************************* s8'!1rHd eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) _v(5vx_
{ GetConic eID, entity, curv, conic &kn?=NW v$+A! eo SetConic eID, entity, 1/Rpost, CCpost K7C!ZXw~ Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost VbTX;? hTWZIW@ '************************************************************************* !T2{xmHKv$ 'Lens thickness (Position of posterior lens surface) }gFa9M< '************************************************************************* WncHgz K4H27SH parID = FindFullName( "Geometry.Arizona Eye.Lens" ) `z.sWF|f!O +Z-{6C ' Delete any z-shift(s) LpI4R count = 0 k<Xb<U While GetOperationCount(eID)>count t=My=pG GetOperation eID, count, op etUfdZ If op.Type="ShiftZ" Then _/"e'@z DeleteOperation eID,count P[$idRS& count=count-1 Jr%F#/ End If q&O9W?E8dG count=count+1 lxbC 7?O Wend ]Nw]po+ L>&{<M_ 'Set new z-shift 4E}Q<?UYSt op.Type = "ShiftZ" N H:Bdl3 op.val1 = tlens ,\1Rf. op.parent = parID ~p:hqi1+<+ AddOperation eID, op ~IPATG Print "Set lens thickness = " & tlens qsN_EMgbdn #Ye0*` '************************************************************************* lp5'-Jo 'Lens index of refraction 6' \M:'<0e '************************************************************************* T~SkFZ eID = FindMaterial( "Lens" ) 9eE
FX7 GetModelMaterial eID, mat %&lwp |Q@( <'8= mat.Nd = nlens \}<J>R@ SetModelMaterial eID, mat /QCg E~ Print "Set lens index of refraction = " & nlens y5D3zqCG |5q,%9_ '************************************************************************* \{Je!# 'Pupil diameter EG_P^<z '************************************************************************* &uV|Ie8@q eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) G=CP17&h6 \<y|[ 'Adjust pupil diameter (trimming volume inner hole) Q84XmXm| )(1tDQ`L> SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 74(bo\ e(OKE7 ' Adjust pupil location to just in front of the lens y]!mN parID = FindFullName( "Geometry.Arizona Eye" ) B{S^t\T$ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) B[f:T% count = 0 OMab! While GetOperationCount(eID)>count ]C|xo.=?] GetOperation eID, count, op 8Bxb~* If op.Type="ShiftZ" Then M?n}{0E4 DeleteOperation eID,count -:Juxh count=count-1 &4M,)Q ( End If [s%uE+``S count=count+1 $z5C+K@ Wend EIg:@o&Jj op.Type = "ShiftZ" q'Y)Y(d op.val1 = taq-0.01 iRv\:.aQ. op.parent = parID 3XUsw1,[ AddOperation eID, op _PP-'^ U \@^`
G Print "Set pupil diameter = " & pupilDiam :D !/.0 0Yr-Q;O<f 'Update AZ Eye subassembly Description 3Ea/)EB] eID = FindFullName( "Geometry.Arizona Eye" ) nv:VX{% GetEntity eID, entity ag!q:6& entity.Description = "Accommodation = " & A & "D" =}F$r5] SetEntity eID, entity WtMDHfwqu\ P4s,N|bs` Update `mN5s q Print "DONE!" .bRDz:?j -8t&&fIA End Sub 1%N[DA^<\ 5d)\Z0s 如果屈光度是4,光瞳直径是4,则会输出如下数据: rp!{QG [*Vo`WgbD Accommodation = 4 Diopters "z{rC} Pupil Diameter = 4 mm QnIF{TS= Set aqueous humor thickness = 2.81 >WY\P4)k Set anterior lens radius = 10.4 and conic constant = -2.375869 xJ\>;$CY Set posterior lens radius = -4.424557 and conic constant = -3.081019 *p^*>~i9) Set lens thickness = 3.927 U%tpNWB Set lens index of refraction = 1.42672 6CNxb Set pupil diameter = 4 M#SGZ~=1r DONE!
|
|