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2022-02-25 09:52 |
Arizona眼睛模型
简介 $#0%gs/x `B^?Za,xN 人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 &<L+;k~P% ^^v\ T 模型 4u"O/rt
yy%J{; 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 (0Y6tcV]R Table 1. AZ眼睛模型的定义 [attachment=111140] K}Aaflq ZZ4W?);; 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. F n6>n04v u<):gI 光源 {At1]> aLP2p] 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 96 C|R }n8,Ga% [attachment=111141] 图1. 光源和提示信息使用 iS02uVmBZ E4WoKuE1$ 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。 2&P'rmFm 4,uH 4[7 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。 QHA<7Wg [attachment=111142] 图2. 字母F光源的设定方法光 =7Nm=5@ 2<<,aL* [attachment=111143] 图3. 字母F在视网膜上位置点列图 R$v{ p[ (2<0kqj% 视网膜的散射 #OG_OI MT a.Ubs 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。 jH\@Oc;7 D
@T,j4o [attachment=111144] 图4. 视网膜朗伯散射设定 fNQ.FAK": w!tQU9+* 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。 TVYO`9:CW U
JY`P4( [attachment=111145] 图5. 视网膜重点采样规格设定 aQkgkV;~ L{osh0 脚本 *"4
OXyV $Nnz|y 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: R$NH [Tz [attachment=111146] 图6. 用户对话框的创建与编辑 2v yB[( [attachment=111147] 图7. 用户对话框编辑器 *O+YhoR? NNS n]LP 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。 |VTm5.23 余下的脚本计算与屈光度有关的所有参数。 N#Y4nllJ Xv6z>z. 分析 oO!@s` R)ejIKtY 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 pX|\J>u) [attachment=111148] 图7. 字母F在视网膜上颜色分析 _! \X>rfz k$#
@_ 脚本代码 j2g#t ZA+$ZU^
- Option Explicit 'Remove this to enable non-dimensioned variables to be used. Q:lSKf
IZniRd; Dim entity As T_ENTITY vY6eg IO Dim op As T_OPERATION
;OE{& Dim mat As T_MODELMATERIAL \2pJ ] Dim A As Double &A]*"lt|w Dim pupilDiam As Double l8n#sGA % Dim eID As Long ,)u}8ty3j Dim parID As Long PUF"^9v Dim count As Integer ,RDxu7iT Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ,NPU0IDG> Dim tlens As Double, nlens As Double zZGPA j Dim curv As Double, conic As Double Hk(w\
Dim ok As Long vNHMe{,u AZxOq !B Sub Main ok2$ p (Sv 7^}j '用户输入对话框 JaiYVx( Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 4f'WF5S/}8 TextBox 220,21,40,21,.TextBox1 'default: 0 y2o?a6` Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 A<QYW,:| OKButton 40,91,90,21 +|r)
;>b CancelButton 190,91,90,21 Ilsh
Jo Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 /%=p-By<V TextBox 220,49,40,21,.TextBox2 'default: 4 %t`a-m End Dialog ;9/6X#;$ Dim dlg As UserDialog }ZlJ uFW4A ok = Dialog (dlg) #c./<<P5} -;_NdL@ If ok=0 Then 'cancel button was pressed X_!Sm Print "Execution cancelled." HkGzyDt End Y[X5S{H`wj End If 0+m"eGwTm 9Or3X/:o 'Assign accommodation and pupil diameter & use defaults if field left empty KSc&6UVz^ If dlg.TextBox1 = "" Then {M$mrmG A = 0 'Default accommodation 8pg?g'A~} Else #<MLW4P A = CDbl(dlg.TextBox1) AW!|xA6'`: End If VsNqYFHes& 8~Rja If dlg.TextBox2 = "" Then )p).}" pupilDiam = 4 'Default pupil diameter 9L*gxI> Else qd%5[A pupilDiam = CDbl(dlg.TextBox2) 1Hy End If kS[k*bN0 hSQP
'6 Print " " b=Zg1SqV Print "Accommodation = " & A & " Diopters" 4Q,HhqV' Print "Pupil Diameter = " & pupilDiam & " mm" plv"/K JM bv)E>%Yy ' Calculate new parameters with accommodation Z"mpE+U* taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness 7E%ehM6Y \# lh b Rant = 12.0 - 0.4*A 'Radius of anterior lens +d2+w1o^V CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens <YUc?NF =uYSZR Rpost = -5.224557 + 0.2*A 'Radius of posterior lens 7Q/v#_e( CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens s@'};E^]@r #Z"N\49 tlens = 3.767 + 0.04*A 'Lens thickness K/,
B fu?>O/Gn/ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction I`5F&8J{ r%&hiobMYs 'Adjust parameters to account for accommodation Qo0okir VX[{X8PkS '************************************************************************* @lc1Ipfk" 'Aqueous thickness (Position of Lens) (|I0C 'Ki '************************************************************************* >6@*%LM eID = FindFullName( "Geometry.Arizona Eye.Lens" ) CDO_A \ GetCustomElement eID, entity [f:>tRdH Ra;e#)7X parID = FindFullName( "Geometry.Arizona Eye" ) *J 7>6N:- 'i%Azzv ' Delete any shift(s) in z i6h:%n]Io count = 0 XaR(q2s While GetOperationCount(eID)>count .Xg%><{~ GetOperation eID, count, op 7Aq4YjbX If op.Type="ShiftZ" Then /?9e{,\s DeleteOperation eID,count |*Z'WUv count=count-1 X:j&+d2g0/ End If 23U9+ count=count+1 Yu9Ccj` Wend 1;?b-FEq: /:z}WAW 'Set new shift in @>ONp|}@qI op.Type = "ShiftZ" U@BVVH?,o op.val1 = taq VS%8f.7ep op.parent = parID D4c}z#}*0 AddOperation eID, op Ud*.[GRD~ Print "Set aqueous humor thickness = " & taq-0.55 VrQw;-rQ DL2e9 '************************************************************************* E IsA2 f 'Radius and conic constant of anterior lens f]J?-ks '************************************************************************* ?Xlmt$Jp eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) vJtQ&,zG GetConic eID, entity, curv, conic l!~8 nm*1JA.: SetConic eID, entity, 1/Rant, CCant pn{.oXomf Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant @H]g_yw [: o-("S|A- '*************************************************************************
vF]?i 'Radius and conic constant of posterior lens zbl h_6 '************************************************************************* RgRyo
eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 85w
D<bN27 GetConic eID, entity, curv, conic Kcsje_I-M IW$&V``v SetConic eID, entity, 1/Rpost, CCpost h:a5FK@ Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3543[W#a ag:#82C '************************************************************************* wAF>C[ <\ 'Lens thickness (Position of posterior lens surface) 1Q#hanh_` '************************************************************************* \X
Nb 9- AWh{dM parID = FindFullName( "Geometry.Arizona Eye.Lens" ) =y0!-y HTQ.kV ' Delete any z-shift(s) }{bO~L7 count = 0 t=xO12Z While GetOperationCount(eID)>count NO`LSF GetOperation eID, count, op h'MX{Wm. If op.Type="ShiftZ" Then v srce DeleteOperation eID,count .NQoqXR count=count-1 rYJt;/RtR} End If :2 QA# count=count+1 ##}a0\x| Wend UF D_ UF,T 'Set new z-shift Y0&w;P op.Type = "ShiftZ" Q]{DhDz?+ op.val1 = tlens z* zLK[t+ op.parent = parID }b)?o@9}: AddOperation eID, op va~:oA Print "Set lens thickness = " & tlens \@MGOaR] M}(4>W '************************************************************************* h*_r='
E 'Lens index of refraction }{=%j~V;& '************************************************************************* &y3_>!L eID = FindMaterial( "Lens" ) Wq&TbWR GetModelMaterial eID, mat o~mY,7@a qe`W~a9x mat.Nd = nlens g RSM~< SetModelMaterial eID, mat q'C'S#qqn Print "Set lens index of refraction = " & nlens b]hRmW :3Ty%W&& '************************************************************************* #uu wzE*M_ 'Pupil diameter r/:9j(yxr '************************************************************************* _$MoMg{uJH eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) XfViLBY(
> 2>ce(4Gky 'Adjust pupil diameter (trimming volume inner hole) C\$7C5/ OFQsfW3O SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" X k<X:,T m[ifcDZ(e ' Adjust pupil location to just in front of the lens x*Z"~'DI parID = FindFullName( "Geometry.Arizona Eye" ) <:q]t6]$ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !6f#OAP\ count = 0 `.L8<
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