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2021-10-22 09:55 |
Arizona眼睛模型
简介 Y00hc8< d69synEw>k 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。 C"*8bVx]$n xf7_|l 模型 />X"'G PK&\pkX 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。 %E"dha JY s?yl4\]Muf
Table 1. AZ眼睛模型的定义 +HSKFp 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. &&>Tfzh jU}iQM 光源 ]kir@NMv> qa>H@`P 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。 eJy}W / 3EA+tG4KnO gWGh:.*T
图1. 光源和提示信息使用 F@l d#O 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。 CQns:.`$` Koi-b 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 s= bP@[Gj
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图2. 字母F光源的设定方法光 ec&K}+p@
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图3. 字母F在视网膜上位置点列图 kKs}E| T 视网膜的散射 oIv\Xdc8 1 <i ";5+ 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 #/
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图4. 视网膜朗伯散射设定 1wLEkp!~ 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 uwc@~=; VT2f\d[Q )ZMR4U$+v
图5. 视网膜重点采样规格设定 -+z8bZ 脚本 7U2?in}?Qi nU,~*Us 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: ') K'Ea y1bo28
图6. 用户对话框的创建与编辑 q+U&lw|"w
图7. 用户对话框编辑器 R*l3 zn> 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。 h'"~t#r 余下的脚本计算与屈光度有关的所有参数。 >c=-uI #A 7|=E 分析 =3EE-%eF! "Ky&x$dje 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 c+ukVn`r &R,QJ4L
图7. 字母F在视网膜上颜色分析 Hn}m}A 脚本代码 j_0xE;g"] giHqc7-PaX Option Explicit 'Remove this to enable non-dimensioned variables to be used. Vtv1{/@+c t[p/65L>8 Dim entity As T_ENTITY ?D+H2[n\a
Dim op As T_OPERATION PM3fJhx Dim mat As T_MODELMATERIAL nP+jkNn3 Dim A As Double }$` PZUw> Dim pupilDiam As Double fS]Z`U" Dim eID As Long ]Q -.Y-J/O Dim parID As Long A-l[f\ Dim count As Integer ,!QtViA7 Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /pL'G` Dim tlens As Double, nlens As Double R,`3 SW() Dim curv As Double, conic As Double IweNe`Z Dim ok As Long c!a1@G >">grDX Sub Main eQJyO9$G C1x(4&h '用户输入对话框 ~_|CXPiQ8 Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 NEt_UcC TextBox 220,21,40,21,.TextBox1 'default: 0 br')%f}m Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 a)'
P/P OKButton 40,91,90,21 yL_\&v CancelButton 190,91,90,21 h*V~.H Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 \t]_UNGyW TextBox 220,49,40,21,.TextBox2 'default: 4 +J3Y}A4W3X End Dialog NY/-9W5T4 Dim dlg As UserDialog LY2QKjgP 0Om<+]).R ok = Dialog (dlg) z{nd4qOsD 7 b8pWM If ok=0 Then 'cancel button was pressed LJOJ2x Print "Execution cancelled." ]Cp`qayct End kudXwj End If I^m9(L4% GpCjoNcW{ 'Assign accommodation and pupil diameter & use defaults if field left empty _VJG@>F9- If dlg.TextBox1 = "" Then p:xVi0 A = 0 'Default accommodation nTHCb>,vM Else d5'4RYfkQ A = CDbl(dlg.TextBox1) +TN*6V{D End If "\qm +g 6|Xm8,]yRw If dlg.TextBox2 = "" Then BOme`0A pupilDiam = 4 'Default pupil diameter UB]]oC< Else )D"2Q: pupilDiam = CDbl(dlg.TextBox2) 9`Xr7gmQf End If 3aFD*S r[P+F Print " " YXIAVSnr Print "Accommodation = " & A & " Diopters" _+d*ljP)l3 Print "Pupil Diameter = " & pupilDiam & " mm" [s F/sa3 Z`>m ' Calculate new parameters with accommodation c3J12+~; taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness ]JlM/ i!+0''i{# Rant = 12.0 - 0.4*A 'Radius of anterior lens |H;+9( CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens qcoTt~\ ycrM8Mu
3 Rpost = -5.224557 + 0.2*A 'Radius of posterior lens Mh=j^ [4Q CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens _CG
ED{b@ #,;Q|)AD:e tlens = 3.767 + 0.04*A 'Lens thickness lbC9^~T+ _*n
4W^8 nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction J#?z/ 3v( |9]_<X[ic 'Adjust parameters to account for accommodation a7"Aq:IjU ?L6pB]l8b '************************************************************************* \I 7,1I 'Aqueous thickness (Position of Lens) pQk@
+r '************************************************************************* u_6x{",5I eID = FindFullName( "Geometry.Arizona Eye.Lens" ) `It3X.^} GetCustomElement eID, entity VJgYXPE
` 40%<E parID = FindFullName( "Geometry.Arizona Eye" ) `{xKU8j^ U&gI_z[ ' Delete any shift(s) in z H4uHCkj count = 0 y0,>_MS While GetOperationCount(eID)>count !_>o2 GetOperation eID, count, op e,T^8_> If op.Type="ShiftZ" Then 4oN*J +"=+ DeleteOperation eID,count )^m"fQ+ count=count-1 nc;iJ/\4 End If R,m|+[sl count=count+1 cnj32H^+ Wend "8/BVW^bv &S8,-~U 'Set new shift in Vj6w7hz op.Type = "ShiftZ" B4x@{rtER op.val1 = taq HrHtA] op.parent = parID 7-d.eNQl AddOperation eID, op &[_D'jm+S0 Print "Set aqueous humor thickness = " & taq-0.55 n= FOB0= =*KY)X '************************************************************************* a=M/0N{! 'Radius and conic constant of anterior lens '?d5L+9 '************************************************************************* ^IO\J{U{"x eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) K1zH\wH GetConic eID, entity, curv, conic !nTI(-- VUzRA"DP| SetConic eID, entity, 1/Rant, CCant bkiMF$K,K Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant %Q zk aXJ rtz ]PH '************************************************************************* jz,Gj}3; 'Radius and conic constant of posterior lens Pp`[E/
qj4 '************************************************************************* TsY
nsLQY eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) $.3J1DU GetConic eID, entity, curv, conic dlBr2 9 z4JhLef % SetConic eID, entity, 1/Rpost, CCpost X-`PF Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost A}_0iwG ow*^z78M{ '************************************************************************* lA n^)EL 'Lens thickness (Position of posterior lens surface) uLrZl0%HT~ '************************************************************************* H6<3'P [E9)Da_)i parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3z
-="_p (1)b> 6 ' Delete any z-shift(s) o':K4r; count = 0 rs,:pU While GetOperationCount(eID)>count Vsd4; GetOperation eID, count, op -=)+)9~G If op.Type="ShiftZ" Then Ted!*HKlB DeleteOperation eID,count )p[Qj58 count=count-1 &0SgEUZr End If W$:D#;jz`h count=count+1 L
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#"Yn Wend T*92 o:^ 76b2 3| 'Set new z-shift wexa\o op.Type = "ShiftZ" U3t)yr h op.val1 = tlens =4K:l}} op.parent = parID /@0 AddOperation eID, op fkD-mRKw Print "Set lens thickness = " & tlens `h<>_zpjY w$jq2?l '************************************************************************* I36ClOG 'Lens index of refraction :b<< '************************************************************************* P7*?E* eID = FindMaterial( "Lens" ) @^nE^; GetModelMaterial eID, mat n\u3$nGL1` /~P4<1 mat.Nd = nlens E+~1GKd SetModelMaterial eID, mat 56H~MnX Print "Set lens index of refraction = " & nlens 5E}!TL$ f9^MLb6) '************************************************************************* na3lbwq 'Pupil diameter ,AG k4] '************************************************************************* a@m
64l) eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Xvxj-\ - &"clBRVg 'Adjust pupil diameter (trimming volume inner hole) 4q\gFFV4
A{)p#K8 SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" NUX$)c 9a]h;r8,9z ' Adjust pupil location to just in front of the lens 4_ kg/ parID = FindFullName( "Geometry.Arizona Eye" ) Gg6<4T1 eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) a6hDw'8! count = 0 J1Oe`my While GetOperationCount(eID)>count x{1S!A^ GetOperation eID, count, op ?y,z If op.Type="ShiftZ" Then nS]Ih 0(K DeleteOperation eID,count a 9Kws[ count=count-1 \hZye20 End If vGD D count=count+1 b;"Z`/h Wend x,#? op.Type = "ShiftZ" 'v%v*Ujf[ op.val1 = taq-0.01 AP0z~e op.parent = parID YeB)]$'?u` AddOperation eID, op L+.-aB2!d :@^T^ Print "Set pupil diameter = " & pupilDiam nI,-ftMD-| ||'A9 'Update AZ Eye subassembly Description _o{w<b& eID = FindFullName( "Geometry.Arizona Eye" ) Wn5xX5H C GetEntity eID, entity .`/6[Zp entity.Description = "Accommodation = " & A & "D" 4td9=dNA+l SetEntity eID, entity d+%Rg\v SlD7 \X&~ Update AIt;~x Print "DONE!" !0Eo9bU%@ b21@iW End Sub 5KL??ao- `bjPOA(g 如果屈光度是4,光瞳直径是4,则会输出如下数据: [wM]w AV;x'H7G Accommodation = 4 Diopters _dwJ; j`2 Pupil Diameter = 4 mm 3W55m@w Set aqueous humor thickness = 2.81 B=|m._OL]n Set anterior lens radius = 10.4 and conic constant = -2.375869 ~D_Wqr Set posterior lens radius = -4.424557 and conic constant = -3.081019 077 wk Set lens thickness = 3.927 }!jn%@_y@ Set lens index of refraction = 1.42672 /N=M9i\; Set pupil diameter = 4 pZ&?uo67_ DONE! W"\O+
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