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2016-02-24 12:53 |
FRED运用:Arizona眼睛模型
简介 @"^(} 6 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。 3ep
L'My$ cSj(u%9} 模型 AI .2os* r<*Y1;7H' 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。 z=LO$,JW` `U;V-
Table 1. AZ眼睛模型的定义 [attachment=67931] d%Ku'Jy 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. iz-O~T/^ ?#__# 光源 $-)y59w" +@PZ3
[s 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 K$M,d-
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[attachment=67932] 图1. 光源和提示信息使用 ,aa
%{ 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。 *oIKddZh .|K\1qGW0 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。 87nsWBe !" : arK
[attachment=67933] 图2. 字母F光源的设定方法光 _[
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[attachment=67934] 图3. 字母F在视网膜上位置点列图 y)Lyo'` 视网膜的散射 5gPAX $j H ,I[A~ 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。 OZh+x`' # ix}*whW=U ..^,*
[attachment=67935] 图4. 视网膜朗伯散射设定 $E@ke: 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 5{6ebq55" 2qkC{klC^M &nZ.$UK<
[attachment=67936] 图5. 视网膜重点采样规格设定 ZZ6F0FLXJ 脚本 g:c
@ hO:X\:G 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: KBGJB`D* L:EJ+bNG
[attachment=67937] 图6. 用户对话框的创建与编辑 S[M\com'
[attachment=67938] 图7. 用户对话框编辑器 E0S[TEDa] 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。 P.1iuZ "w 余下的脚本计算与屈光度有关的所有参数。 c5rQkDW *)d|:q3 分析 cWM|COXL+ Qi7^z; 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ^ihXM]1{G BmUzsfD
[attachment=67939] 图7. 字母F在视网膜上颜色分析 _.06^5o 脚本代码 o6KBJx .]H]H *wC Option Explicit 'Remove this to enable non-dimensioned variables to be used. C 127he [I4FU7mpH Dim entity As T_ENTITY Pjb9FCA' Dim op As T_OPERATION mLY * Dim mat As T_MODELMATERIAL 5\Y/s o= Dim A As Double #CQ>d8& Dim pupilDiam As Double L
kq>>?T= Dim eID As Long r IK|} 5 Dim parID As Long A# M Dim count As Integer IfXLnD^|| Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double f|^f^Hu:{ Dim tlens As Double, nlens As Double hy )RV=X Dim curv As Double, conic As Double MM8)yCI Dim ok As Long P/PS(` xBG1up<z Sub Main _gGy(` +%Gm2e;_u '用户输入对话框 #EM'=Q%TO Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 86I* TextBox 220,21,40,21,.TextBox1 'default: 0 1a!h&!$9 Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Elq8WtS OKButton 40,91,90,21 NR[mzJv CancelButton 190,91,90,21 fIcv}Y Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 nz',Zm}, TextBox 220,49,40,21,.TextBox2 'default: 4 -?'CUm*Od End Dialog '~cEdGD9H Dim dlg As UserDialog IyuT=A~Ki ~EM];i ok = Dialog (dlg) .2P?1HpK F1=+<]! If ok=0 Then 'cancel button was pressed 8dhY"& Print "Execution cancelled." u@EM,o End :qp"Ao{M End If zef,*dQY aVYUk7_ < 'Assign accommodation and pupil diameter & use defaults if field left empty bH{aI:9Fb If dlg.TextBox1 = "" Then $(R)
=4 A = 0 'Default accommodation YeLOd Else ]EnaZWyO] A = CDbl(dlg.TextBox1) ;"
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End If d/>,U7eS[+ Fc~w`~tv If dlg.TextBox2 = "" Then C(|5,P#5 pupilDiam = 4 'Default pupil diameter [BBKj)IK Else YMTA`T(+ pupilDiam = CDbl(dlg.TextBox2) !f-o,RJ End If v`BG1&/| &>l8S lC?
Print " " ~,68S^nP)H Print "Accommodation = " & A & " Diopters" ] <3?=$ Print "Pupil Diameter = " & pupilDiam & " mm" <WJ0St ;
,<J:%s ' Calculate new parameters with accommodation 5]l7Z35 taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness |S:!+[ 5I1J)K; Rant = 12.0 - 0.4*A 'Radius of anterior lens \_AEuz3
F CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens |u r~s$8y- _|B&v Rpost = -5.224557 + 0.2*A 'Radius of posterior lens ~hslLUE CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens aSkx#mV G5#}Ed4 tlens = 3.767 + 0.04*A 'Lens thickness @) ZO$h uQ]]]Z(H' nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction zWs*kTtA #7-@k-<| 'Adjust parameters to account for accommodation 5f'g3' ,&&M|,NQ&s '************************************************************************* Tj21YK.mk 'Aqueous thickness (Position of Lens) `XSc > '************************************************************************* aXbNDj
][ eID = FindFullName( "Geometry.Arizona Eye.Lens" ) M2E87w GetCustomElement eID, entity (vAv^A*i} RmWfV parID = FindFullName( "Geometry.Arizona Eye" ) 3$N %iE6 P%+or * ' Delete any shift(s) in z .D,?u"fk| count = 0 4Wla&yy While GetOperationCount(eID)>count :-u-hO5*8 GetOperation eID, count, op A?Nn>xF9X If op.Type="ShiftZ" Then m c\ C DeleteOperation eID,count -|Yh/ count=count-1 >{ECyh; End If dF{6>8D=5B count=count+1 nR o=J5tY Wend L7Qo- 4\1wyN /}M 'Set new shift in mX@j op.Type = "ShiftZ" xHv|ca.E op.val1 = taq t}]9VD9
op.parent = parID ?-8y4
Ex AddOperation eID, op :/@k5#DY Print "Set aqueous humor thickness = " & taq-0.55 nY{i>Y B:O+*3j '************************************************************************* { r6]MS#l1 'Radius and conic constant of anterior lens }c`
?0FQ '************************************************************************* k;;nE o~6 eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) X2\E9hJg GetConic eID, entity, curv, conic ;Ze"<U BgJkrv7~ SetConic eID, entity, 1/Rant, CCant 4ef*9|^x# Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant yy1>r }L +"YTCzv;t '*************************************************************************
Z $!C= 'Radius and conic constant of posterior lens :v#k&Uh3y '************************************************************************* ,'FD}yw4v eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) A#Xj]^-* GetConic eID, entity, curv, conic H9%l?r5 LKqRvPnh SetConic eID, entity, 1/Rpost, CCpost d@-wi%,^ Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost gWFL r~)VGdB+ '************************************************************************* TkA9tFi 'Lens thickness (Position of posterior lens surface) jEZ
" '************************************************************************* NmjzDN yrO?Np parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9n_ eCb)H PPN q:, ' Delete any z-shift(s) [FB&4>V/ count = 0 7.%f01/i While GetOperationCount(eID)>count !loO%3_) GetOperation eID, count, op BApa^j\? If op.Type="ShiftZ" Then %njOX#.w DeleteOperation eID,count F\JLbY{x] count=count-1 #De(*&y2 End If pNuqT* count=count+1 .
/Y&\< Wend zgK;4
22$m ,`<]>;s 'Set new z-shift XHy? op.Type = "ShiftZ" 7 xUE,)? op.val1 = tlens Im6U_JsNZh op.parent = parID t{~@I AddOperation eID, op z=B<
`}@3 Print "Set lens thickness = " & tlens cu<y8
:U< W;.{]x.0 '************************************************************************* {f-XyF1` 'Lens index of refraction .W$
sxVXB '************************************************************************* U3/8A:$y eID = FindMaterial( "Lens" ) /V#7=,, GetModelMaterial eID, mat B7|c`7x( |e:rYLxm: mat.Nd = nlens )&Mq,@ SetModelMaterial eID, mat OMvT;Vgg Print "Set lens index of refraction = " & nlens LaclC]yLU hD*(AJ '************************************************************************* 7x(v? 'Pupil diameter <}cZi4l' '************************************************************************* hox< vr4 eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) l77'Lne fQO
""qh 'Adjust pupil diameter (trimming volume inner hole) .+HcA x{/2 %7 /,m SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" e+{BJN
vz &*A:[b\ ' Adjust pupil location to just in front of the lens ~XKZXGw parID = FindFullName( "Geometry.Arizona Eye" ) _-RyHgX eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) >9MS"t count = 0 FllX za) While GetOperationCount(eID)>count G1/Gq.< GetOperation eID, count, op Hr&Ere8.4p If op.Type="ShiftZ" Then o[oqPN3$Y DeleteOperation eID,count ?aFZOc4
count=count-1 ($'V&x8T End If )P%4:P count=count+1 {!r#f(?uT Wend D7gHE op.Type = "ShiftZ" 7 OWsHlU op.val1 = taq-0.01 %{"dP%|w4} op.parent = parID
#Z0-8<\ AddOperation eID, op d>/Tu_ y ]'g:B p Print "Set pupil diameter = " & pupilDiam G A EZY }uiPvO+&p 'Update AZ Eye subassembly Description *uU4^E( eID = FindFullName( "Geometry.Arizona Eye" ) \447]<u GetEntity eID, entity Zw24f1iY entity.Description = "Accommodation = " & A & "D" SBL+e]P SetEntity eID, entity _r5wF(Y?7 _Jy,yMQ^[_ Update ?;RD u[eD Print "DONE!" In+^V([u+_ Qt~B#R.
V End Sub Z'ao[CG ~ k<SbFp 如果屈光度是4,光瞳直径是4,则会输出如下数据: 9rS,? p&O8qAaO Accommodation = 4 Diopters UFf,+4q Pupil Diameter = 4 mm \HD-vINV; Set aqueous humor thickness = 2.81 Man^<T%F Set anterior lens radius = 10.4 and conic constant = -2.375869 ;j!UY.i Set posterior lens radius = -4.424557 and conic constant = -3.081019 M}KZG'7 Set lens thickness = 3.927 KC]tY9 FK Set lens index of refraction = 1.42672 'e85s%ru Set pupil diameter = 4 `@MPkCy1 DONE! _Fxe|"<^ y+RRg[6|
(文章来源:讯技光电)
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