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2020-12-09 09:18 |
Arizona眼睛模型
简介 4..M *U c4V%>A 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。 iu.v8I;< ItD&L
)) 模型 .L@gq/x) SxI-pH' 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。 Zk ] /m l=PZlH
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Table 1. AZ眼睛模型的定义 [nASMKK0 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. H):(8/>( J!\oH%FJp 光源 aY-7K._</ K1$
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。 +3F%soum95 $W]}m"l Jo''yrJpB
图1. 光源和提示信息使用 /b7]NC% 除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 cDIZkni= Qo~|[]GE 在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 U'aJCM U#Wg"W{
图2. 字母F光源的设定方法光 46##(4RF =Hbf()cN)
图3. 字母F在视网膜上位置点列图 NHiac(&* 视网膜的散射 v`@M IOv 7epil 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 m+Kl
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图4. 视网膜朗伯散射设定 }qT{" *SC 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 \ `;1[m Tq?7-_MLC$ k+BY 3a
图5. 视网膜重点采样规格设定 *,|x
p 脚本 (q@%eor&} )FN\jo!!. 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: 9ZNzC
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图6. 用户对话框的创建与编辑 lVCnu>8
图7. 用户对话框编辑器 K0~=9/ 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。 3rBID 余下的脚本计算与屈光度有关的所有参数。 V :/v
r [y~kF?a 分析 S!rVq,| d p:V1VHT, 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 (&SPMhs_|( ~b@"ir+g4
图7. 字母F在视网膜上颜色分析 tOX-vQ 脚本代码 ++n_$Qug K~4bT= Option Explicit 'Remove this to enable non-dimensioned variables to be used. +%H=+fJ2} uFA}w:Fm Dim entity As T_ENTITY MOPHu
O{^ Dim op As T_OPERATION %l,CJd5 Dim mat As T_MODELMATERIAL `A9fanh Dim A As Double h$mGawvZ~ Dim pupilDiam As Double *R}p9;dpO Dim eID As Long m>|7&l_ Dim parID As Long jvxCCYXR Dim count As Integer 0{
_6le] Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &@FufpPw/ Dim tlens As Double, nlens As Double P%ThW9^vnj Dim curv As Double, conic As Double Jd~M q9( Dim ok As Long &dPUd~&EL I@5$ <SN Sub Main 1]9l
SE!E7 bI^F( '用户输入对话框 cc3/XBo Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 BNe>Lk o TextBox 220,21,40,21,.TextBox1 'default: 0 <*+[E!oi Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 IwBO#HR~) OKButton 40,91,90,21 6v74mIRn'? CancelButton 190,91,90,21 "_2;+@+ Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 U_hzSf TextBox 220,49,40,21,.TextBox2 'default: 4 ~!M" End Dialog ;O|u`fAqT Dim dlg As UserDialog zK I1 dd6%3L{cn ok = Dialog (dlg) p"7[heExw P,b&F If ok=0 Then 'cancel button was pressed VoQhzp6& Print "Execution cancelled." !x\\# 9 End =**Q\Sl End If F@HJ3O9 :Gzp
(@<@e 'Assign accommodation and pupil diameter & use defaults if field left empty GvvKM=1 If dlg.TextBox1 = "" Then 6oFA=CjU{ A = 0 'Default accommodation *K&
$9fah Else
3bJ|L3G A = CDbl(dlg.TextBox1) !]5V{3 End If H:
;XU $e{[fmx If dlg.TextBox2 = "" Then bR1Q77<G\ pupilDiam = 4 'Default pupil diameter TA8 Else ;@:-T/= pupilDiam = CDbl(dlg.TextBox2) rVRv*W End If |DPq~l(d dPxJ`8 Print " " Gm3`/!r Print "Accommodation = " & A & " Diopters" G{O{
p Print "Pupil Diameter = " & pupilDiam & " mm" yqtaQ0F~
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+uc;[` ' Calculate new parameters with accommodation V#+F*w?&D taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness 9Zmq7a
E rZ)7(0BBs Rant = 12.0 - 0.4*A 'Radius of anterior lens [Q\(kd*4 CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens &Nw|(z&$ P}>>$$b\Yi Rpost = -5.224557 + 0.2*A 'Radius of posterior lens ;j[:tt\k CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens O(9*VoD JoZzX{eu" tlens = 3.767 + 0.04*A 'Lens thickness e
'F:LMX V]"pM]>3X nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction =P_*.SgR O3%#Q3c>3 'Adjust parameters to account for accommodation ?AQA>D#W rYg%B6Fp '************************************************************************* la4%Vqwgu 'Aqueous thickness (Position of Lens) #?eMEws '************************************************************************* yF_/.m I eID = FindFullName( "Geometry.Arizona Eye.Lens" ) VR A+p?7- GetCustomElement eID, entity <^'IC9D] ~2yhZ parID = FindFullName( "Geometry.Arizona Eye" ) X?JtEQ~> ne 3t|JZ ' Delete any shift(s) in z B[
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s?: count = 0 ~V?\@R:g While GetOperationCount(eID)>count Nez '1 GetOperation eID, count, op +_gA"I
If op.Type="ShiftZ" Then AMO{ee7Po DeleteOperation eID,count zy8+~\a+Y& count=count-1 sJl>evw End If /11CC \ count=count+1 hstGe>f[6 Wend ,JTyOBB<I jqTK7b 'Set new shift in [a}Idi`
K op.Type = "ShiftZ" U!RIeC op.val1 = taq :<0lC j op.parent = parID -Ekf T_ AddOperation eID, op ljz=u;O) Print "Set aqueous humor thickness = " & taq-0.55 $?VYHkX w vI
v+Q9 '************************************************************************* D5].^*AbZ 'Radius and conic constant of anterior lens FP0GE '************************************************************************* [D?d~pB eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) v;}MHl GetConic eID, entity, curv, conic S@~ReRew2 s.KfMJ"u[ SetConic eID, entity, 1/Rant, CCant 6{g&9~V Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant iU=:YPE+. 1-.i^Hal '************************************************************************* iV\*7 'Radius and conic constant of posterior lens L}A2$@ '************************************************************************* 2Qc_TgWF eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) { Q!Xxe>6 GetConic eID, entity, curv, conic t+^__~IX ) :Px`] 5 SetConic eID, entity, 1/Rpost, CCpost ~(`MP< Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /7Q9(} y`/:E<fVk '************************************************************************* -b?s\X 'Lens thickness (Position of posterior lens surface) M~Er6Zg '************************************************************************* XXD4T9Wy r CUs parID = FindFullName( "Geometry.Arizona Eye.Lens" ) U><$p{) R[m+s=+ ' Delete any z-shift(s) ,.;{J|4P count = 0 Fa{[kJ8z While GetOperationCount(eID)>count OL@$RTh GetOperation eID, count, op y`7b3*P If op.Type="ShiftZ" Then Z]Cd> u DeleteOperation eID,count y7'9KQ count=count-1 ;D%H}+Z End If k?
,/om1 count=count+1 tU>7jo[-p Wend NZ+TTMv zP|^@Homk 'Set new z-shift /U6ry' op.Type = "ShiftZ" '
wp _U/ op.val1 = tlens ~ET XXu${I op.parent = parID
KcpQ[6\ AddOperation eID, op WP^wNi
~> Print "Set lens thickness = " & tlens x}{O9LiR _d>{Hz2 '************************************************************************* ^t`0ul]c 'Lens index of refraction Pv*]AF;9pQ '************************************************************************* /7ykmW eID = FindMaterial( "Lens" ) fOP3`G^\ GetModelMaterial eID, mat )vY )Mg w,0OO
f mat.Nd = nlens #TB
3|= SetModelMaterial eID, mat 7b8y Print "Set lens index of refraction = " & nlens FB3}M)G>M MaF4lFmS '************************************************************************* :8]y*j 'Pupil diameter '<6DLtZl '************************************************************************* on1B~?*D eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &WS'Me vu:] [2"0 'Adjust pupil diameter (trimming volume inner hole) 0E@*&Ru >^ E*7Bfp SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Z
?F_({im HY(XI u ' Adjust pupil location to just in front of the lens +.uQToqy parID = FindFullName( "Geometry.Arizona Eye" ) &fE2zTz eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) z]&?}o count = 0 p ^)3p5w While GetOperationCount(eID)>count xX.{(er GetOperation eID, count, op J"XZnb)E= If op.Type="ShiftZ" Then mgb+HNH%q\ DeleteOperation eID,count c/l^;6O/!\ count=count-1 YU\k D End If Sf2xI' count=count+1 ,G[Y< ~Hy Wend ~9@83Cs2 op.Type = "ShiftZ" {/qQ=$t op.val1 = taq-0.01 1R7tnR@[u op.parent = parID >.uIp4@( AddOperation eID, op hV
fANbs hUEA)c Print "Set pupil diameter = " & pupilDiam dq0!.gBT2 Ml'lZ) 'Update AZ Eye subassembly Description F!-%v5.y eID = FindFullName( "Geometry.Arizona Eye" ) K87yQOjPv GetEntity eID, entity RNt9Qdr4y entity.Description = "Accommodation = " & A & "D" ~y,m7%L SetEntity eID, entity BKYyc6iE bGxHzzU} Update U.Y7]#P: Print "DONE!" `A- aj<r= End Sub ^z51f>C rE0%R+4? 如果屈光度是4,光瞳直径是4,则会输出如下数据: `Q[NrOqe" ,wngS= Accommodation = 4 Diopters AHHV\r Pupil Diameter = 4 mm #5iy^?N"w Set aqueous humor thickness = 2.81 %D~Mij Set anterior lens radius = 10.4 and conic constant = -2.375869 ex66GJQe1 Set posterior lens radius = -4.424557 and conic constant = -3.081019 69`*u<{PC Set lens thickness = 3.927 yJ;Qe_up Set lens index of refraction = 1.42672 ux6p2Sk;K Set pupil diameter = 4 tYhcoV DONE! p6ryUJc6 Mq_P'/ s'bTP(wl9 QQ:2987619807 ncTMcu
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