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2020-12-09 09:18 |
Arizona眼睛模型
简介 NjYpNd?g kn+`2-0 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。 >/1.VT\E {-Yp~HQF 模型 tz1iabZ{ t+m$lqm 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 /LuwPM RBt"7 '
Table 1. AZ眼睛模型的定义 bi#o1jR 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. l:j9lBS hd/5*C{s 光源 A3$
rPb8 CWCE}WU>4 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。 JY9Hqf [7|}h/ c{|soc[#
图1. 光源和提示信息使用 ^L]+e 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。 C*kZ>mbc _P,fJ`w 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。 lQi2ym? Sh2q#7hf
图2. 字母F光源的设定方法光 $qg5m,1? P0'
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图3. 字母F在视网膜上位置点列图 A ;Z%-x 视网膜的散射 S U2`H7C* @iC!Q>D 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ^a<=@0| DrHMlk5 N<"_5
图4. 视网膜朗伯散射设定 uDH)0# 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 |
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图5. 视网膜重点采样规格设定 j(/"}d3osm 脚本 7 &GhJ^Ku 3~s0ux[ 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: <adu^5BI uW Q`
图6. 用户对话框的创建与编辑 }-:
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图7. 用户对话框编辑器 P*I\FV 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 (5_o H 余下的脚本计算与屈光度有关的所有参数。 lSXhHy CEqfsKrsxE 分析 tQo"$ JN}
F_YZV)q!W 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 aH'^`]'_= (Clf]\_II
图7. 字母F在视网膜上颜色分析 VR*5}Qp 脚本代码 f=}u;^ '~3(s?B Option Explicit 'Remove this to enable non-dimensioned variables to be used. \ E[0KvN;O c7wza/r> Dim entity As T_ENTITY =E4nNL? Dim op As T_OPERATION iO<O2A.F Dim mat As T_MODELMATERIAL Qbt
fKn95 Dim A As Double sE>'~+1_O Dim pupilDiam As Double 9L!Vj J Dim eID As Long ^C<dr}8 Dim parID As Long ^]E| >~\ Dim count As Integer ,A[HYc|uy Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double =jg!@H=_i Dim tlens As Double, nlens As Double .(1=iL_3e Dim curv As Double, conic As Double yMX4 f Dim ok As Long -cY/M~ z0g$+bhy Sub Main #?}Y~Oe b$rBxe\ '用户输入对话框 "TN}=^A\F Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 oY +RG|j@ TextBox 220,21,40,21,.TextBox1 'default: 0 R`TM@aaS: Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g&_0)(a\ OKButton 40,91,90,21 d=lZhqY CancelButton 190,91,90,21 pSV
8! Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 V+Cb.$@ TextBox 220,49,40,21,.TextBox2 'default: 4 #BT=
K End Dialog 4XX21<yn Dim dlg As UserDialog L d# v oC<
/}E ok = Dialog (dlg) !ZSC" rp(`V@x3 If ok=0 Then 'cancel button was pressed aASnk2DFd Print "Execution cancelled." z^Oiwzo End _ogT(uYyr End If $5il]D` ~POe0!} 'Assign accommodation and pupil diameter & use defaults if field left empty H(?z?2b p If dlg.TextBox1 = "" Then I>9rfmmTI A = 0 'Default accommodation 1AoBsEnd Else +k8><_vr} A = CDbl(dlg.TextBox1) Dk]Y\: End If <`6-J `. 3@6f%Dyj If dlg.TextBox2 = "" Then g*Cs/w pupilDiam = 4 'Default pupil diameter OP:;?Fs9` Else Kpj0IfC,10 pupilDiam = CDbl(dlg.TextBox2) x`C; End If 0{A VH/S Z~$& h Print " " tk1qgjE(? Print "Accommodation = " & A & " Diopters" !u4oo- Print "Pupil Diameter = " & pupilDiam & " mm" d&R/f Im hr]NW>; ' Calculate new parameters with accommodation 3=;iC6
` taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness CHBCi) '6h *pI3"_ Rant = 12.0 - 0.4*A 'Radius of anterior lens H+*o @0C\~ CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens 9RR1$( f )O2^?Q quS Rpost = -5.224557 + 0.2*A 'Radius of posterior lens -*?a*q/#nQ CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens ^f3F~XhY3 3fM tlens = 3.767 + 0.04*A 'Lens thickness <=19KSGFt L$(W*
PG} nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction IybMO5Mwn tYmWze.j 'Adjust parameters to account for accommodation PX]A1Kt? 4(B,aU>y '************************************************************************* L & PhABZ 'Aqueous thickness (Position of Lens) o
@*3<_e '************************************************************************* =;@5Ue
J eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 299; N GetCustomElement eID, entity <M+ZlF-` _Vp9Y:mX2 parID = FindFullName( "Geometry.Arizona Eye" ) V=E9*$b] }.`ycLW' ' Delete any shift(s) in z /H!I90 count = 0 K6|*-Wo. While GetOperationCount(eID)>count 9LCV"xgX GetOperation eID, count, op 5F
<zW-; If op.Type="ShiftZ" Then 7b'XQ/rs DeleteOperation eID,count v?d~H`L count=count-1 ,)oUdwR k End If jsi\*5=9p< count=count+1 (h`||48d Wend zL)m!:_ Lxd*W2$3_ 'Set new shift in oN)K2&M0 op.Type = "ShiftZ" % YU(,83(+ op.val1 = taq 5QMu=/ op.parent = parID VCvuZU{< AddOperation eID, op p^~lQ8t Print "Set aqueous humor thickness = " & taq-0.55 O`|'2x{[O O'$:wc# '************************************************************************* X$%RJ3t e 'Radius and conic constant of anterior lens =b !f '************************************************************************* HjV83S; eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) }$iH3#E8 GetConic eID, entity, curv, conic KvktC|~? mC J/gWDY SetConic eID, entity, 1/Rant, CCant ZJ+q<n_4} Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant D!)'c(b a.c2ScXG '************************************************************************* SDdK5@1O4o 'Radius and conic constant of posterior lens yrkd#m '************************************************************************* R.>/%o eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) p,ZubRJ" GetConic eID, entity, curv, conic [/5>)HK} C {kW!|h&' SetConic eID, entity, 1/Rpost, CCpost 37M7bB0 Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #2x\d Cw Z{& '*************************************************************************
4[bw/[ 'Lens thickness (Position of posterior lens surface)
bQ '************************************************************************* c67O/ B( R2u[IVZW:- parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,'82;oP4 vbFY} ' Delete any z-shift(s) i3#]_ p{ count = 0 4S03W
While GetOperationCount(eID)>count \ m2[ GetOperation eID, count, op B.{0,bW?
If op.Type="ShiftZ" Then "FG6R' DeleteOperation eID,count a>""MC2 count=count-1 PjRKYa_U End If y .
AN0 count=count+1 5#WZXhlc} Wend I>ofSaN B;?a. 81~ 'Set new z-shift ^#gGA_H op.Type = "ShiftZ" 2R|2yAh op.val1 = tlens bumS>: op.parent = parID Xo]FOJ5 AddOperation eID, op MZ% P(5 Print "Set lens thickness = " & tlens k]I<% S{fNeK '************************************************************************* @8V8gV?zm 'Lens index of refraction bpKb<c '************************************************************************* sowkxw.^Q eID = FindMaterial( "Lens" ) 8FbBv"LI,g GetModelMaterial eID, mat |@V<}2zCZ o.y4&bC14; mat.Nd = nlens Qv']*C[!z SetModelMaterial eID, mat MIi:\m5 Print "Set lens index of refraction = " & nlens 5UjXpS Pm"
,7 '************************************************************************* 5n?fZ?6( 'Pupil diameter GT#i Y* '************************************************************************* 7j._3'M=Kc eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) .5_w^4`b ]FsPlxk6 'Adjust pupil diameter (trimming volume inner hole) ?vM{9!M b"{7f SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" YzEa?F*$ DAc jx:~ ' Adjust pupil location to just in front of the lens L88oh&M parID = FindFullName( "Geometry.Arizona Eye" ) 6VCw>x eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) syBYH5 count = 0 //|9J(B] While GetOperationCount(eID)>count 'B6D&xn'%& GetOperation eID, count, op dHd{9ftyF If op.Type="ShiftZ" Then bzB9u& DeleteOperation eID,count ?XW+&!ar count=count-1 >W 8!YOc End If W99Fb+$I count=count+1 kw?RUt0-V Wend }2JSa8 op.Type = "ShiftZ" g[:5@fI#* op.val1 = taq-0.01 KHdj#3<AR op.parent = parID &ec_jxF AddOperation eID, op hb^e2@i;Oq >Li
~Og@ Print "Set pupil diameter = " & pupilDiam !"p,9 /m9t2,KB 'Update AZ Eye subassembly Description l
^$$d8 eID = FindFullName( "Geometry.Arizona Eye" ) 21w<8:Vg GetEntity eID, entity ,!bOzth2>K entity.Description = "Accommodation = " & A & "D" ?Yz.tg SetEntity eID, entity vC+mC4~/( jS|(g##4 Update ilpg() Print "DONE!" ou96
P<B 4}#*M2wb End Sub Lf7iOW9U3 wBCnP 如果屈光度是4,光瞳直径是4,则会输出如下数据: =XudL^GF Yo(8mtYU Accommodation = 4 Diopters ~hP[[? Pupil Diameter = 4 mm .DCp)&m
l; Set aqueous humor thickness = 2.81 9lOUE Set anterior lens radius = 10.4 and conic constant = -2.375869 }2DeqY Set posterior lens radius = -4.424557 and conic constant = -3.081019 y 0M&Bh Set lens thickness = 3.927 := *>:*.Kb Set lens index of refraction = 1.42672 9 Q].cDe[ Set pupil diameter = 4 ~5]AXi'e~ DONE! P),%S9jP; I>G)wRpfR' r|rV1<d QQ:2987619807 ]FQ4v.7
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