[技术]Arizona眼睛模型 [复制链接]

简介 p%#=OtkC  
/VHQ!Wi  
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。 <tI_
u ~P  

t2_pwd*B  
模型 XtftG7r9S  
La8D%N  
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。 G_v^IM#B=  
*5z"Xy3J  
EHH+)mlo  
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. <7*d2  
tdOox87YK  
光源 9?I?;l{  
Xmv^O  
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。 EY}*}-3  
f5P@PG]{  
?F^O7\rw  
`7 3I}%?  
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。 P*g:rg  
%'&_Po
\  
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。 J|@kF!6  
+z O.|`+  
XGSgx  
<G /a-
Z  
视网膜的散射 W0\ n?$ZC~  
8],tGMu  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 #<81`%  
&d@N3y  
0I7 r{T  
.9$ 7 +  
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。 i'MpS  
eeCrH
t4;  
KA{JSi  
CH] +S>$  
脚本 @WTzFjv@?4  
^ Q  
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： 1+9}Xnxb  
i _YJq;(  
UO}Yr8Z;  
@%gth@8  
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。 H{+[ ,l  
余下的脚本计算与屈光度有关的所有参数。 OYj~"-3y)
 
O>/&-Wk=  
分析 N'=b8J-fF  
VL8yL`~zc.  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 li  
M&5De{LS}  
2T3b6  
脚本代码 Fh~ pB>t  
[KNA5(Y0  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. kA{eT  
VY j pl  
Dim entity As T_ENTITY p{w:^l(  
Dim op As T_OPERATION nrJW.F]S8[  
Dim mat As T_MODELMATERIAL s/0~!0  
Dim A As Double !d{Ijs'T  
Dim pupilDiam As Double ^wMZG'/  
Dim eID As Long de,4Ms!%  
Dim parID As Long N&]_U%#Q  
Dim count As Integer Qkx}A7sK  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double r%vO^8FQ  
Dim tlens As Double, nlens As Double x?n13C  
Dim curv As Double, conic As Double WNo<0|X  
Dim ok As Long L /V;;  
#s0Wx47~  
Sub Main Y%#r&de  
VZCCMh-  
    '用户输入对话框 F~zrg+VDjL  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 YTV|]xpR  
        TextBox 220,21,40,21,.TextBox1 'default: 0 e8Vt
KVcY  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 I@l }%L  
        OKButton 40,91,90,21 y/OPN<=*  
        CancelButton 190,91,90,21 c-=z<:Kf  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 cp L'  
        TextBox 220,49,40,21,.TextBox2 'default: 4 <gjA(xT5  
    End Dialog }J(o!2.  
    Dim dlg As UserDialog IpKpj"eoLy  
lvk r2Meu<  
    ok = Dialog (dlg) *IV_evgM7  
t+2,;G  
    If ok=0 Then    'cancel button was pressed dobqYd
4`  
        Print "Execution cancelled." M:cW/&ZJ  
        End <a)L5<#  
    End If ghDOz 3  
w/Y6m.i1  
    'Assign accommodation and pupil diameter & use defaults if field left empty F.@U X
{J  
    If dlg.TextBox1 = "" Then <S(`e/#[  
        A = 0           'Default accommodation %C~LKs5oH  
    Else /=~o|-n8@  
        A = CDbl(dlg.TextBox1) #6F/:j;  
    End If a:}&v^v  
0/,Dy2h  
    If dlg.TextBox2 = "" Then faPgp  
        pupilDiam = 4   'Default pupil diameter ;*q  
    Else q+cx.Rc#  
        pupilDiam = CDbl(dlg.TextBox2) Z{rD4S@^  
    End If !y-,r4\@`  
YZQF*fj  
    Print " " >SaT?k1E  
    Print "Accommodation = " & A & " Diopters" ;}QM#5Xdt  
    Print "Pupil Diameter = " & pupilDiam & " mm" GcC
MCR3  
B|.8+Q  
    ' Calculate new parameters with accommodation Pef$-3aP>E  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness DY?;Z98P?  
hp!. P1b  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens q+?>shqsZ  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ))eQZ3ap9  
y)0wM~E;2  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens g"|Z1iy|9  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Oj0,Urs7  
N]7#Q.(~  
    tlens = 3.767 + 0.04*A                  'Lens thickness }4wIfI83K,  
$}z%}v  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction khS >  
RZ GD5`n  
    'Adjust parameters to account for accommodation :%kJ9zW  
dBM> ;S;v  
    '************************************************************************* U!Eo*?LU$  
    'Aqueous thickness (Position of Lens) m5KAKpCR,  
    '************************************************************************* _~a5;[~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) hH*/[|z  
    GetCustomElement eID, entity 4j VFzO%.  
#SIIhpjA(  
    parID = FindFullName( "Geometry.Arizona Eye" ) :+$/B N:iO  
ns`njx}C  
    ' Delete any shift(s) in z xa$p,_W:'  
    count = 0 O[v(kH'  
    While GetOperationCount(eID)>count _MST8  
        GetOperation eID, count, op s7G!4en  
        If op.Type="ShiftZ" Then qTi%].F"G  
            DeleteOperation eID,count 2%gLq  
            count=count-1 d|RDx;rl8  
        End If i)mQ?Y#o  
        count=count+1 qe_59'K  
    Wend Ld$e -dB  
d;WXlE;  
    'Set new shift in o.M.zkP a  
    op.Type = "ShiftZ" *7:HO{P>Y  
    op.val1 = taq ;+Uc}=  
    op.parent = parID C Ch38qBp  
    AddOperation eID, op %MUh_63bB  
    Print "Set aqueous humor thickness = " & taq-0.55 a?5R;I B  
5"o)^8!>  
    '************************************************************************* } D0Y8  
    'Radius and conic constant of anterior lens #Y;tobB  
    '************************************************************************* A.>TD
=Nz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &<\i37y  
    GetConic eID, entity, curv, conic N9jSiRJ  
\o2cztl=  
    SetConic eID, entity, 1/Rant, CCant "j] r  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant iQj2aK Gs  
Ub9p&=]h  
    '************************************************************************* o u*`~K|R  
    'Radius and conic constant of posterior lens \Czuf   
    '************************************************************************* ds|L'7  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) UKf
poDhEe  
    GetConic eID, entity, curv, conic DP<[Uz&  
$9m>(b/;n  
    SetConic eID, entity, 1/Rpost, CCpost ]5`Y^hS_g  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ._5"FUg  
BjsF5~+\  
    '************************************************************************* }!n90 9L  
    'Lens thickness (Position of posterior lens surface) t9(sSl  
    '************************************************************************* gW(7jFl  
B`1"4[{  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) =abBD   
;0 No@G;z  
    ' Delete any z-shift(s) <oP"kh<D4  
    count = 0 ,[t>N>10TH  
    While GetOperationCount(eID)>count B9(e"cMm  
        GetOperation eID, count, op PShluhY  
        If op.Type="ShiftZ" Then Al1BnFB  
            DeleteOperation eID,count wS%aN@ay3  
            count=count-1 XEvDtDR  
        End If Z{gJm9  
        count=count+1 p@Ng.HE  
    Wend  Lkl+f~m  
;*=MI/"N  
    'Set new z-shift <sNkyQ  
    op.Type = "ShiftZ" g9K7_T #W  
    op.val1 = tlens yYri.n  
    op.parent = parID lIDGL05f'  
    AddOperation eID, op +M %zOX/  
    Print "Set lens thickness = " & tlens $Z!7@_Ys  
_(.,<R5  
    '************************************************************************* yB~`A>~M  
    'Lens index of refraction &hri4p/  
    '************************************************************************* =i:6&Y~VGq  
    eID = FindMaterial( "Lens" ) O!=ae|  
    GetModelMaterial eID, mat F^bzE5#  
U#{^29ik=o  
    mat.Nd = nlens @& vtY._  
    SetModelMaterial eID, mat '4J];Nj0  
    Print "Set lens index of refraction = " & nlens U9ZWSDs  
d9>k5!  
    '************************************************************************* ?}D|]i34  
    'Pupil diameter Q $5U5hb
 
    '************************************************************************* $&l} ABn  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Dd:;8Xo  
@cz\'v6E  
    'Adjust pupil diameter (trimming volume inner hole) tbr1mw'G  
8LZmr|/F*  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 0>KW94  
JE$aYs<(TF  
    ' Adjust pupil location to just in front of the lens q;{# ~<"+  
    parID = FindFullName( "Geometry.Arizona Eye" ) EX.`6,:+2  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) +o94w^'^$b  
    count = 0 5\6S5JyIL  
    While GetOperationCount(eID)>count (g>>   
        GetOperation eID, count, op yu>DVD  
        If op.Type="ShiftZ" Then u_~*)w+mS@  
            DeleteOperation eID,count 4LfD{-_uW  
            count=count-1 ',<Bo{  
        End If Ka$YKY,  
        count=count+1 ~c*$w O\  
    Wend Np?%pB!Q  
    op.Type = "ShiftZ" B-`,h pp  
    op.val1 = taq-0.01 3TS(il9A  
    op.parent = parID %1Pn;bUU!  
    AddOperation eID, op ?%Pd:~4D  
qbwX*E~;  
    Print "Set pupil diameter = " & pupilDiam zYW+Goz/C  
f4Yn=D=_  
    'Update AZ Eye subassembly Description `J(im  
    eID = FindFullName( "Geometry.Arizona Eye" ) ee0)%hc1t  
    GetEntity eID, entity )`sEdVxbr  
    entity.Description = "Accommodation = " & A & "D" G?t<4MTv  
    SetEntity eID, entity }%;o#!<N(@  
tAM t7p-  
    Update x?unE@?\S  
    Print "DONE!" MI,b`pQ  
     N7b+GqYpF>  
End Sub v[O}~E7'  
!&k}YF  
如果屈光度是4，光瞳直径是4，则会输出如下数据： ? !dy  
j m]d:=4_  
Accommodation = 4 Diopters scsN2#D7U/  
Pupil Diameter = 4 mm N5SePA\ ,?  
Set aqueous humor thickness = 2.81 ^=lh|C\#  
Set anterior lens radius = 10.4 and conic constant = -2.375869 VW[!%<  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 RzOs,  
Set lens thickness = 3.927 g2&%bNQ-5  
Set lens index of refraction = 1.42672 1JFCYJy  
Set pupil diameter = 4 $z>L $,c>  
DONE! 5ZXP$.