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2020-12-09 09:18 |
Arizona眼睛模型
简介 9~2}hXm; "7mYs)= 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。 a|Io)Qhr WvQK$}Ax4N 模型 (LbAP9Zj#f osPJ%I`^ 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。
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Table 1. AZ眼睛模型的定义 >>oR@ 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. ~w_4
nE , 7&`V=C 光源 B8;jRY {>PN}fk2QP 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。
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图1. 光源和提示信息使用 ,#:* dl 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 yV[9 ( 5#3/ 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 QWz5iM 91d@/z
图2. 字母F光源的设定方法光 qDHiyg^u t\Pn67t
图3. 字母F在视网膜上位置点列图 ;43Ye
^= 视网膜的散射 ,WSK
' g S xK9P 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 H'7AIY} k`FCyO "h?;)Ye
图4. 视网膜朗伯散射设定 #2l6'gWE0 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 &9X`tCnL f'P}]_3( AT Dm$ *
图5. 视网膜重点采样规格设定 '?7th>pC 脚本 =.NZ{G 8fA9yQ8 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: &S[tI$ O92a*)
图6. 用户对话框的创建与编辑 'NCxVbyYD
图7. 用户对话框编辑器 ^T*^L=L_( 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。 7.g)_W{7} 余下的脚本计算与屈光度有关的所有参数。 7oaa) y
Nb&;E7 H 分析 JA0$Fz Y*nzOD$ 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 vl59|W6 }%LwaRT
图7. 字母F在视网膜上颜色分析 oEPO0O 脚本代码 Cx$C+ y\0<f `v6 Option Explicit 'Remove this to enable non-dimensioned variables to be used. Vfew )]I ER,,K._?B Dim entity As T_ENTITY wUkLe-n,dE Dim op As T_OPERATION KQ'fp:5|/@ Dim mat As T_MODELMATERIAL 0_b7*\x c Dim A As Double c*MSd Dim pupilDiam As Double *4}lV8 Dim eID As Long L-ans2? Dim parID As Long C {.{>M Dim count As Integer uV1H iv- Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Z-[nHSf Dim tlens As Double, nlens As Double w6tb vhcmU Dim curv As Double, conic As Double LL3RC6;e Dim ok As Long Kp,}7%hDw! k1;,eB Sub Main <jdS0YT T8Sgu6:*R '用户输入对话框 0_JbE Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 g*$
0G TextBox 220,21,40,21,.TextBox1 'default: 0 ^aVoH/q*C Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *]G&pmMs OKButton 40,91,90,21 ]:TX> X! CancelButton 190,91,90,21 : sIZ+3 Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1
v|+}>g TextBox 220,49,40,21,.TextBox2 'default: 4 Fs_,RXW" End Dialog 7Cf%v`B4D Dim dlg As UserDialog
(2vR8 Ycb<'M*jE ok = Dialog (dlg) !NuYx9L?L :&$4&\_F If ok=0 Then 'cancel button was pressed oiAU}iK: Print "Execution cancelled." YLk; ^? End js
)G End If }%k,PYe/ <LM<, 'Assign accommodation and pupil diameter & use defaults if field left empty 3}O.B
r| If dlg.TextBox1 = "" Then N>i1TM2 A = 0 'Default accommodation &8t?OpB =h Else (zkh`8L A = CDbl(dlg.TextBox1) I%xrDiK97 End If r$ue1bH}| }8WpX2U If dlg.TextBox2 = "" Then HN>eS Y+ pupilDiam = 4 'Default pupil diameter &*g5kh{ Else 6 .DJRY pupilDiam = CDbl(dlg.TextBox2) ;@K,>$ur- End If s%]-Sw9 W.p->,N Print " " %o<&O(Y Print "Accommodation = " & A & " Diopters" 2a*1q#MpAt Print "Pupil Diameter = " & pupilDiam & " mm" ]!H*oP8a* %kD WUJZ ' Calculate new parameters with accommodation KmV#%
d taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness SqY;2: k1>%wR Rant = 12.0 - 0.4*A 'Radius of anterior lens &:L8; m CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens 6, ag\ 'ntb.S) Rpost = -5.224557 + 0.2*A 'Radius of posterior lens q,d]i/T CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens rBs7,h pPCxa#OV tlens = 3.767 + 0.04*A 'Lens thickness E=gD{1,? uR)itmc? nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction 93fKv 9<<$uf.B 'Adjust parameters to account for accommodation Ed#%F-1sX Szi4M&!K '************************************************************************* 7=om / 'Aqueous thickness (Position of Lens) 6f6_ztTL '************************************************************************* @&+h3dV.V eID = FindFullName( "Geometry.Arizona Eye.Lens" ) `6j?2plZ GetCustomElement eID, entity FVG|5'V^ 4q@o4C<0 parID = FindFullName( "Geometry.Arizona Eye" ) W_8FzXA ?>q=Nf^ Q. ' Delete any shift(s) in z 8!>uC&bE8 count = 0 m'k`p5[=h While GetOperationCount(eID)>count Tv3 ZNh GetOperation eID, count, op doc5;?6 If op.Type="ShiftZ" Then !=&]#-;b DeleteOperation eID,count y5a^xRDw count=count-1 /Re1QS End If 2EE/xnwX count=count+1 ] >ipC,v Wend &:]_a?|*S !dhZs?/UI 'Set new shift in =i%2/kdi0b op.Type = "ShiftZ" * VW\ op.val1 = taq 1sc #!^Oo op.parent = parID 7u5B/M! AddOperation eID, op XP2=x_"y Print "Set aqueous humor thickness = " & taq-0.55 k`)LO`)) AG}'
W '************************************************************************* \07Vh6cj 'Radius and conic constant of anterior lens a^[io1}- '************************************************************************* q(.%f3( eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 58e{WC GetConic eID, entity, curv, conic w?M*n<)
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xcM+OX1 SetConic eID, entity, 1/Rant, CCant ' 1P_* Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8x,;B_Zu fbuop&FN+q '************************************************************************* 7C2/^x P 'Radius and conic constant of posterior lens m$LZ3=v%8 '************************************************************************* D4#,9?us eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) )CR8-z1` GetConic eID, entity, curv, conic )STt3. =j;o,
J:( SetConic eID, entity, 1/Rpost, CCpost P#ru-0DD Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost $Uewv
+ &<UOi@ '************************************************************************* #i2q}/w5`C 'Lens thickness (Position of posterior lens surface) 2~J|x+
'************************************************************************* M!X@-t# 3&' STPpW parID = FindFullName( "Geometry.Arizona Eye.Lens" ) _%1.D0<~-E 5,Q('t#J ' Delete any z-shift(s) (/*-M]> count = 0 &OzJ^G\o While GetOperationCount(eID)>count 6@F Z,e GetOperation eID, count, op }f-rWe{gs> If op.Type="ShiftZ" Then sL/Lw
WH DeleteOperation eID,count n<hwstk count=count-1 7H>dv' End If ^E:;8h4$9 count=count+1 LoCxoAg Wend Yhsb$wu ,MvvW{EY 'Set new z-shift pwZ &2&| op.Type = "ShiftZ" 5~[Fh2+ op.val1 = tlens ;N1FP* op.parent = parID wy-!1wd AddOperation eID, op lJYv2EZ Print "Set lens thickness = " & tlens
?5GjH~ dO8Z {wfs '************************************************************************* X*Q7Yu 'Lens index of refraction g)p[A 4 '************************************************************************* u8,T>VNVw eID = FindMaterial( "Lens" ) Tf[]vqa`G GetModelMaterial eID, mat s~63JDy"E DHJnz>bE mat.Nd = nlens gTQ6B,`/8 SetModelMaterial eID, mat _9gn;F Print "Set lens index of refraction = " & nlens _|Dt6 4%6Q+LS']Q '************************************************************************* :iWV:0)P 'Pupil diameter ,}|V'y '************************************************************************* Q@j:b]Y9 eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 9,>M/_8> 2'}2r ~6 'Adjust pupil diameter (trimming volume inner hole) x
p$0J<2 34l=U? SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" dJ;;l7":~ n&Tv]- ' Adjust pupil location to just in front of the lens LpiLk| 2i parID = FindFullName( "Geometry.Arizona Eye" ) 0ib 6}L% eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) "l@~WE count = 0 EXi+pm While GetOperationCount(eID)>count M<L<mP} GetOperation eID, count, op xAO]u[J If op.Type="ShiftZ" Then r\1*N.O3|O DeleteOperation eID,count \G"/Myi count=count-1 (l^lS=x End If @]7\.>) count=count+1 Q:LuRE!t Wend gbh:Y}_FU op.Type = "ShiftZ" }v!6BU6<Q op.val1 = taq-0.01 ";xEuX op.parent = parID j)0R*_-B[ AddOperation eID, op ?t"PawBWE 2#[Y/p Print "Set pupil diameter = " & pupilDiam oe<Y,%u"6 9c 6V&b 'Update AZ Eye subassembly Description 0t&H1xsxX eID = FindFullName( "Geometry.Arizona Eye" ) uXC?fMWp. GetEntity eID, entity FSB$D)4z>b entity.Description = "Accommodation = " & A & "D" 4~/6d9f SetEntity eID, entity ]aR4U` D0P% .r"v Update i_@RWka< Print "DONE!" 5 6R,+sN a]k&$ End Sub %!S |{nI.> 如果屈光度是4,光瞳直径是4,则会输出如下数据: -a[{cu{ mc=*wr$ Accommodation = 4 Diopters ?x0yiV~dL Pupil Diameter = 4 mm V Y3{1Dlf Set aqueous humor thickness = 2.81 ]3,0
8JW= Set anterior lens radius = 10.4 and conic constant = -2.375869 }M9al@" Set posterior lens radius = -4.424557 and conic constant = -3.081019 a8 1%M Set lens thickness = 3.927 Dfo9jYPf Set lens index of refraction = 1.42672 X3nhqQTZ Set pupil diameter = 4 LA+MX0* DONE! gK( 4<PO' ("6W.i> r;C\eN QQ:2987619807 EHHxCq?
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