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2022-02-25 09:52 |
Arizona眼睛模型
简介 32/MkuY^u /M3Y~l$ 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。 MBhWMCN2 /.o^R6 模型 P#XID 2; b;cdIl!3 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。 .R./0Ot tx Table 1. AZ眼睛模型的定义 [attachment=111140] Nz],IG. CJJzCVj 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. m6[0Kws& fM^qQM[lG 光源 *22nVKi{ b#hDHSdZ, 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。 fi$-;Gz 7lBAxqr2 [attachment=111141] 图1. 光源和提示信息使用 }A7j/uy}s f,:9N 5Z 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 t-0a7
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%Q^o5m 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 l33Pm/V2? [attachment=111142] 图2. 字母F光源的设定方法光 I.94v
#r ]A<~XIu [attachment=111143] 图3. 字母F在视网膜上位置点列图 {O`w,dMOI i* NH'o/
视网膜的散射 C@L$~iG Y#lk6 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。 P%(O| t<|NLk. [attachment=111144] 图4. 视网膜朗伯散射设定 oWC@w YtfVD7m 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。 UmclTGn Ndcg/d [attachment=111145] 图5. 视网膜重点采样规格设定 m/y2WlcRx KNLfp1! 脚本 ek}a}.3 { U}PiY"S< 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: Vy938qX [attachment=111146] 图6. 用户对话框的创建与编辑 2VJR$Pao [attachment=111147] 图7. 用户对话框编辑器 *UmI]E{g3( }t%!9hr5D 如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 DFd%9*N 余下的脚本计算与屈光度有关的所有参数。 371
TvZ4 5wh|=**/ 分析 thvYL.U: i2&ed_h<? 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ~tR~?b T [attachment=111148] 图7. 字母F在视网膜上颜色分析 [>1OJY.S}T *]VFvh 脚本代码 [.S#rGYk (3#Cl
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- Option Explicit 'Remove this to enable non-dimensioned variables to be used. ,J{ei7TN
K/3)g9Z&io Dim entity As T_ENTITY %ve:hym* Dim op As T_OPERATION JMz;BAHT Dim mat As T_MODELMATERIAL eZdu2.;< Dim A As Double HsHB!mQV Dim pupilDiam As Double ]5$eAYq Dim eID As Long a8i]]1Blz Dim parID As Long 0 rXx RQ Dim count As Integer 24 )(5!:" Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double U]vYV Dim tlens As Double, nlens As Double J<dVTxK12 Dim curv As Double, conic As Double <B6&I$Wc+ Dim ok As Long kLni{IYN7 .72S o T Sub Main V8HnUuz [-;_ZFS{ '用户输入对话框 <p\6AnkMr Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 0VGPEKRh TextBox 220,21,40,21,.TextBox1 'default: 0 k=B]&F Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 t$xY #: OKButton 40,91,90,21 _;~,Cgfi CancelButton 190,91,90,21 oNU0 qZ5 Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 r]l!WRn TextBox 220,49,40,21,.TextBox2 'default: 4 xgNJ eQ End Dialog L?Qg#YSd~ Dim dlg As UserDialog ])
rrG/3 '&gF> ok = Dialog (dlg) n ;$5Cq!v= *WIj4G.d If ok=0 Then 'cancel button was pressed
}f8Uc+ Print "Execution cancelled." 00SbH$SU End _',prZ* End If Z6_N$Z.A L2pp6bW 'Assign accommodation and pupil diameter & use defaults if field left empty _/s(7y! If dlg.TextBox1 = "" Then i 4%xfN A = 0 'Default accommodation hvuIxqv !y Else B]Y}Hu A = CDbl(dlg.TextBox1) NyVnA End If m"fNK$_d -t2+|J*
If dlg.TextBox2 = "" Then :w<V pupilDiam = 4 'Default pupil diameter ZP;j9T! Else p"FW&Q=PN pupilDiam = CDbl(dlg.TextBox2) E2"q3_,, End If FFH_d <q F^5?\ Print " " Bnb#{tL Print "Accommodation = " & A & " Diopters" 6q]5Es< Print "Pupil Diameter = " & pupilDiam & " mm" -GqT7`:(H4 B:e
@0049 ' Calculate new parameters with accommodation \L(*]:EP taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness Pj4/xX 1\g6)|R-+ Rant = 12.0 - 0.4*A 'Radius of anterior lens H]$)Eg%6 CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens g"?Y+j n[]tXrhU Rpost = -5.224557 + 0.2*A 'Radius of posterior lens FRS>KO=3 CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens \uXcLhXN Wt=| tlens = 3.767 + 0.04*A 'Lens thickness EC\yzH*X 1xbK'i:-S nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction LNa $
X5` ;}1xn3THCn 'Adjust parameters to account for accommodation *_KFW@bC: h-m\% |D '************************************************************************* fuA&7gNC 'Aqueous thickness (Position of Lens) raCi 8 '************************************************************************* UY <e&Npo eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Ojt`^r !V GetCustomElement eID, entity g=]u^& g*F '[Z." parID = FindFullName( "Geometry.Arizona Eye" ) HS.^y
x KLL;e/Gf ' Delete any shift(s) in z x#Q>J"g count = 0 ecgtUb8K While GetOperationCount(eID)>count u&9 r2R959 GetOperation eID, count, op <7n4_RlF! If op.Type="ShiftZ" Then 2OwV^-OG DeleteOperation eID,count q-`RI*1] count=count-1 IR- dU<<9O End If 9{$<0,? count=count+1 ylB7* >[ Wend jU3Z*Z)zN GHHav12][ 'Set new shift in +]|Z%;im op.Type = "ShiftZ" $YXMI",tt< op.val1 = taq r)1'ePI" op.parent = parID %uoQ9lD' AddOperation eID, op h[?O+Z^ Print "Set aqueous humor thickness = " & taq-0.55 OKP9CLg9
VL/|tL>E^ '************************************************************************* =e}H'5?! 'Radius and conic constant of anterior lens gi-Yqco '************************************************************************* -YjA+XP eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) C:uz6i1 GetConic eID, entity, curv, conic #_|sgS?1 0z[dlHi SetConic eID, entity, 1/Rant, CCant .(X
lg-H, Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant F! X}(N?t 1$2D O '************************************************************************* NFr:y<0>z 'Radius and conic constant of posterior lens eXkujjSw" '************************************************************************* 8NU`^L:1 eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ^47PLLRP GetConic eID, entity, curv, conic nD0}wiL{ [F*4EGB SetConic eID, entity, 1/Rpost, CCpost UDe |Sb Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost L3p` DEw8*MN '************************************************************************* /% I7Vc 'Lens thickness (Position of posterior lens surface) +*n-<x5" '************************************************************************* +,&O1ykY =L5GhA~ parID = FindFullName( "Geometry.Arizona Eye.Lens" ) +e-,ST&w( #k$)i[aI-
' Delete any z-shift(s) 4:sjH.u< count = 0 Cv*x2KF
G While GetOperationCount(eID)>count QeDQo GetOperation eID, count, op NB7Y{)
w If op.Type="ShiftZ" Then M@(^AK{mU DeleteOperation eID,count 9M /SH$Qy count=count-1 >;#=gM End If z*a8sr count=count+1 1TM~*<Jb Wend `Rdm-[& jS!`2li?{ 'Set new z-shift G|m1.=DJm op.Type = "ShiftZ" 20TCG0%x op.val1 = tlens Qe'g3z> op.parent = parID ?,=f\Fz! AddOperation eID, op ,=~z6[ Print "Set lens thickness = " & tlens S|zW^|YU tURc bwV '************************************************************************* BT_tOEL# 'Lens index of refraction jDRe)bo4 '************************************************************************* BYM3jXWi0v eID = FindMaterial( "Lens" ) cM&2SRBZ GetModelMaterial eID, mat %y<ejM erl:9. mat.Nd = nlens kL90&nP SetModelMaterial eID, mat o]LRzI Print "Set lens index of refraction = " & nlens M|[ZpM+ F=)&98^v$_ '************************************************************************* f7hXQ|$ 'Pupil diameter u=&Bmn_ '************************************************************************* B(DrY1ztj eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) s-W[.r| WV"jH9"[ 'Adjust pupil diameter (trimming volume inner hole) *RR[H6B^]X b}G24{ SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 70B)|<$ %vO<9fE|1 ' Adjust pupil location to just in front of the lens FZH\Q~IUV parID = FindFullName( "Geometry.Arizona Eye" ) .5Q:Xp eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) `*\{.;,]# count = 0 6e25V4e?I While GetOperationCount(eID)>count %gcc
y| GetOperation eID, count, op (X6sSO If op.Type="ShiftZ" Then 2uk x (Z
DeleteOperation eID,count 1j\aH&)GH count=count-1 Sg]
J7;] End If X['2b78k count=count+1 {6d b{ ay_ Wend 7W9~1
.SC op.Type = "ShiftZ" !7U\J] op.val1 = taq-0.01 N8!TZ~1$ op.parent = parID (D{Ys'{q AddOperation eID, op a}d6o;li R:aYL~ Print "Set pupil diameter = " & pupilDiam #vf_D?^ i_F$&?) 'Update AZ Eye subassembly Description l9/:FiJ_ eID = FindFullName( "Geometry.Arizona Eye" ) qUf)j\7"Fn GetEntity eID, entity |*,jU;NI entity.Description = "Accommodation = " & A & "D" BN@,/m9OQ% SetEntity eID, entity YCw('i(| mYNEz
@ Update y~F<9;$= Print "DONE!" "L3Xd][ hN(L@0) End Sub aEx(rLd+ L"rcv:QWZa 如果屈光度是4,光瞳直径是4,则会输出如下数据: g-yi xU *+8%kn`c Accommodation = 4 Diopters gvnj&h.GV Pupil Diameter = 4 mm bj"z8 kP Set aqueous humor thickness = 2.81 9b6!CNe! Set anterior lens radius = 10.4 and conic constant = -2.375869
o A~4p( Set posterior lens radius = -4.424557 and conic constant = -3.081019 dALK0U Set lens thickness = 3.927 9.0WKcwg Set lens index of refraction = 1.42672 daOS8_py Set pupil diameter = 4 P Tnac DONE!
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