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2020-12-09 09:18 |
Arizona眼睛模型
简介 'fYF1gR4 jAdZS\?w 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。 ~? :>=x .=zBUvy 模型 trZU_eouI
tYp 185 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。 0ev='v8? L=dQ,yA
Table 1. AZ眼睛模型的定义 P1^O0) 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. 3e9UD N2 8@/MrEOW# 光源 (>uA(#Z
(aLjW= 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。 |G/U%?` pV O{7I F!g;}_s9
图1. 光源和提示信息使用 s Fx0 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。 |rI;OvZ\ qJE_4/<^! 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。 1DlXsup&?# /VD[: sU7
图2. 字母F光源的设定方法光 ]X> I(p@ 4K
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图3. 字母F在视网膜上位置点列图 PZVH=dagq 视网膜的散射 M+I9k;N6& $/
g<h 在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 xXfv({ CjEzsjqe<I qP-_xpu]R
图4. 视网膜朗伯散射设定 4X!4S6JfB 注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 ^r,0aNzAs bB)$=7\ > Edsanx
图5. 视网膜重点采样规格设定 L)qUBp@MW 脚本 qHvU4v cG&@PO]+. 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: !<out4Mz" 4I9Yr
图6. 用户对话框的创建与编辑 NKc<nYdK?
图7. 用户对话框编辑器 NLu[<u U* 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。 +F.@n_}p-I 余下的脚本计算与屈光度有关的所有参数。 N) PkE>%X `KZu/r-M9 分析 B6@q`Bmw. eaDR-g" 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 gjx-tp 1. ]^8CtgC
图7. 字母F在视网膜上颜色分析 i(;.Y 脚本代码 SAdo9m' #=)!\ Option Explicit 'Remove this to enable non-dimensioned variables to be used. Gqj(2.AY o'Fyo4Qd Dim entity As T_ENTITY RI+Y+z Dim op As T_OPERATION 8llXpe Dim mat As T_MODELMATERIAL \4>w17qng Dim A As Double xm5?C>vu( Dim pupilDiam As Double {jv+ JL"5 Dim eID As Long 5V~vND*
s Dim parID As Long JTObyAoW Dim count As Integer R"l6|9tmP Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double l-Ha*>gX[j Dim tlens As Double, nlens As Double p+5J Dim curv As Double, conic As Double oW(EV4J" Dim ok As Long $j8CF3d.6 5<e{)$C Sub Main YQyI{ [#YzU^^Ib '用户输入对话框 YQtq?&0Ct Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Jd?qvE>Pp TextBox 220,21,40,21,.TextBox1 'default: 0 6(x53y__ Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 :pNS$g[ OKButton 40,91,90,21 C]fX=~?bGQ CancelButton 190,91,90,21 sSc~q+xz Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 RNQq"c\ TextBox 220,49,40,21,.TextBox2 'default: 4 & ['L7 End Dialog EZzR"W/ Dim dlg As UserDialog ~d3@x\I? LwTdmR ok = Dialog (dlg) cNN0-<#c Z9MR"!0 If ok=0 Then 'cancel button was pressed ]Yf^O @<<> Print "Execution cancelled." !@wUARQ End X
@pm !c# End If ZJ~0o2xZ' 9HPmJ`b 'Assign accommodation and pupil diameter & use defaults if field left empty gs7_Q If dlg.TextBox1 = "" Then >56fa6=3@ A = 0 'Default accommodation CBNt
_y Else sdiWQv A = CDbl(dlg.TextBox1) 8 R7w$3pp\ End If '9zKaL ~kj96w4eAR If dlg.TextBox2 = "" Then ^Sj;~ pupilDiam = 4 'Default pupil diameter O*bzp-6\ Else zGNW5S9G pupilDiam = CDbl(dlg.TextBox2) )_n(u3' End If b|@zjh;]A7 zg@i7T Print " " x!vyjp Print "Accommodation = " & A & " Diopters" <L11s%5- Print "Pupil Diameter = " & pupilDiam & " mm" B/qN1D]U. =
Ezg3$%- ' Calculate new parameters with accommodation |(2#KMEWa taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness MM*~X"A Xit@.:a; Rant = 12.0 - 0.4*A 'Radius of anterior lens $E[M[1j CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens n~BQq-1 G@Sqg Rpost = -5.224557 + 0.2*A 'Radius of posterior lens if*~cPnN CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens 8DMqjt3B ?.uhp tlens = 3.767 + 0.04*A 'Lens thickness _L` uCjA 7'65+c[& nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction F|y0q:U %`K{0b 'Adjust parameters to account for accommodation fAz4>_4 E.sZjo1 '************************************************************************* );yZyWDV 'Aqueous thickness (Position of Lens) 6uKth mr '************************************************************************* \x:U`T eID = FindFullName( "Geometry.Arizona Eye.Lens" ) =hd0Ui>x GetCustomElement eID, entity :SW
vH- ] )V+/@ 4 parID = FindFullName( "Geometry.Arizona Eye" ) #Ef! X PC+Soh* ' Delete any shift(s) in z 3-6MGL9 count = 0 H3vnc\d~ While GetOperationCount(eID)>count NS""][# GetOperation eID, count, op iOCs%J If op.Type="ShiftZ" Then +-SO}P DeleteOperation eID,count zHg=K / count=count-1 "w0~f6o End If ?b'(39fj count=count+1 f*88k='\W Wend xdDe@G;" [`s.fkb8 'Set new shift in v@ qDR|?^ op.Type = "ShiftZ" {QmK4(k?|c op.val1 = taq ` ~^ My~f op.parent = parID y`5
? AddOperation eID, op <HTz Print "Set aqueous humor thickness = " & taq-0.55 ntB#2S aIQC[ry '************************************************************************* !>ZBb\EyK 'Radius and conic constant of anterior lens ?azLaAG '************************************************************************* ~Ym*QSD eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {Y=k`t, GetConic eID, entity, curv, conic n@h$V\&\iM #O,w{S SetConic eID, entity, 1/Rant, CCant p,|)qr:M Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant hR:i! t2.jg?`k '************************************************************************* 6(t'B!x 'Radius and conic constant of posterior lens QmGK!
H>3 '************************************************************************* H^`J(J+ eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) C`3XOth GetConic eID, entity, curv, conic J#4pA{01w \fSruhD SetConic eID, entity, 1/Rpost, CCpost |; mET
Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost {iq^CHAVK <0hVDk~ '************************************************************************* '/Vm[L$d 'Lens thickness (Position of posterior lens surface) nRw.82eK. '************************************************************************* zVe,HKF/ Oml3=TV parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5T9[a 9-&@Y ' Delete any z-shift(s) LkK[,Qj count = 0 <;>k[P' While GetOperationCount(eID)>count qK@,O\ GetOperation eID, count, op 5 ';[|f If op.Type="ShiftZ" Then xO%yjG= DeleteOperation eID,count W>?aZv count=count-1 tQyQ+1 End If |F'eT
4 count=count+1 RtxAIMzh? Wend Dp#27Yzc %iYro8g!, 'Set new z-shift *Sbc
8Y op.Type = "ShiftZ" CN-4FI)1D9 op.val1 = tlens ~R=p[h) op.parent = parID N!v>2"x8q AddOperation eID, op +]yVSns
3 Print "Set lens thickness = " & tlens [xGL0Z%)t Z$m&F0g '************************************************************************* _U*1D*kLI[ 'Lens index of refraction {- MhhRa5 '************************************************************************* )[&j&AI eID = FindMaterial( "Lens" ) $(OL#>9Ly GetModelMaterial eID, mat %wu,ce]* c$u#U~~ mat.Nd = nlens }095U(@ SetModelMaterial eID, mat 9n\v{k= Print "Set lens index of refraction = " & nlens ww%4MHPp8 ,y/m5-D! '************************************************************************* -%[6q 'Pupil diameter +, rm '************************************************************************* xs"\c7pC eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) bZQ_j#{$ AI9=?X<kh 'Adjust pupil diameter (trimming volume inner hole) ]i
`~J ~+RrL,t# SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (\%+id|/q@ NX]6RZr- ' Adjust pupil location to just in front of the lens eR3MU]zF parID = FindFullName( "Geometry.Arizona Eye" ) cyL|.2, eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ,S, R6#3G count = 0 -*?{/QmKb While GetOperationCount(eID)>count &mA{_|> GetOperation eID, count, op ,?
&$c+ If op.Type="ShiftZ" Then WS@8Z0@RD DeleteOperation eID,count ry* 9 count=count-1 E`iE]O End If tf9a- s count=count+1 H
a`V"X{} Wend
)$2h:dw_ op.Type = "ShiftZ" z KG]7 op.val1 = taq-0.01 @XKVdtG op.parent = parID ;b,
bHL AddOperation eID, op AIA4c"w.EO $')Uie<!8 Print "Set pupil diameter = " & pupilDiam ~@D!E/hZx /"1[qT\F 'Update AZ Eye subassembly Description Vt4,?" eID = FindFullName( "Geometry.Arizona Eye" ) z}7U>y6` GetEntity eID, entity <<1_rRL] entity.Description = "Accommodation = " & A & "D" S?~/
V ] SetEntity eID, entity +j6^g* elP#s5l4 Update t@`Sa< Print "DONE!" DJR r F;Ubdxwwl End Sub .ldBl 0Jm)2@ 如果屈光度是4,光瞳直径是4,则会输出如下数据: x^UAtKSy `SYq/6$VEH Accommodation = 4 Diopters 2|8$@*-\ Pupil Diameter = 4 mm '[[*(4a3 Set aqueous humor thickness = 2.81 ~T'$gl Set anterior lens radius = 10.4 and conic constant = -2.375869 X.ZY1vO Set posterior lens radius = -4.424557 and conic constant = -3.081019 ~NO'8Mr Set lens thickness = 3.927 DEpn> Set lens index of refraction = 1.42672 yrrP#F Set pupil diameter = 4 I;?np DONE! H^w Inkf> M 0RVEhX rJcZ a# QQ:2987619807 ,#80`&\%
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