[技术]Arizona眼睛模型 [复制链接]

简介 O\=U'6@  
x3X^\Ig  
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。 iy{n"#uX  
AOh\%|}  
模型 {J`]6ba  
| rY.IbL  
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。 p&Os5zw;|  
'QR @G  
XiP xg[;  
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. +`;YK7o  

y">_$  
光源 !/1a
ot^(  
Mq!vu!  
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。 Q
ktj  
g;N)K3\2
 
*aE/\b  
b4l=Bg"  
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。 );8Nj zX1  
^qn,b/>L  
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。 fjc8@S5x9j  
f-w-K)y$ht  
&$\B&Hp@  
 ,\HZIl[8  
视网膜的散射 <!+T#)Qi  
%Tc P[<  
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。 B%~hVpm,eM  
x.=Np\#\G-  
m)5,ut/  
9Ai e$=  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 TFIP>$*_C  
~ULD{Ov'F  
(\CT "u-  
|4=Du-e  
脚本 sj"zgE)  
`k^d)9  
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： )#^5$5  
0^5*@vt  
av}Giz  
 j|Q*L<J  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 [Pn(d[$z  
余下的脚本计算与屈光度有关的所有参数。 /7s^OkQ  
+#|| w9p  
分析 v;S_7#  
OGDCC/  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 O{4G'CgN(  
/(iq^  
3Pj#k|(f[0  
脚本代码 Ukf4Q\@w  
b7thu5  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. w=dTa5  
I}?+>cf  
Dim entity As T_ENTITY 2X:OS/  
Dim op As T_OPERATION 2Hh5gD|>  
Dim mat As T_MODELMATERIAL 7GY3_`  
Dim A As Double EAPLe{qw:q  
Dim pupilDiam As Double SFj:|S=v6j  
Dim eID As Long !x%$xC^Iz  
Dim parID As Long #:UP'v=w  
Dim count As Integer 6RA4@bIG  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double kjS9?>i  
Dim tlens As Double, nlens As Double 2 Nr*  
Dim curv As Double, conic As Double IB'gY0*  
Dim ok As Long "[Z'n9C  
( 04clU^F  
Sub Main _m;H$N~I#  
nIckI!U#D  
    '用户输入对话框 K!L0|WH%!  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 z 1~2w:  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ,aA%,C.0U
 
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 :1O49g3R  
        OKButton 40,91,90,21 n7CwGN%  
        CancelButton 190,91,90,21 ><l|&&e-  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 X:0-FCT;\  
        TextBox 220,49,40,21,.TextBox2 'default: 4 dKG2f  
    End Dialog 8p91ni'  
    Dim dlg As UserDialog '}F=U(!  
x{o&nhuk[S  
    ok = Dialog (dlg) R6xJw2;_  
@4ccZ&`  
    If ok=0 Then    'cancel button was pressed AW\#)Em  
        Print "Execution cancelled." v`G[6Z  
        End i_[nW  
    End If eu^B  
Xb/W[rcs  
    'Assign accommodation and pupil diameter & use defaults if field left empty vrGx<0$  
    If dlg.TextBox1 = "" Then 9'{i |xG  
        A = 0           'Default accommodation n'i~1pM,?  
    Else 54^2=bp  
        A = CDbl(dlg.TextBox1) _e9S"``
 
    End If !_a@autj  
xDsB%~  
    If dlg.TextBox2 = "" Then JSCZX:5  
        pupilDiam = 4   'Default pupil diameter V\2&?#GZ  
    Else 3|Vh[iAa\  
        pupilDiam = CDbl(dlg.TextBox2) v 7g?  
    End If P {8d.  
*# 7 1aZ  
    Print " " uhf% zG  
    Print "Accommodation = " & A & " Diopters" axpn*
(yE  
    Print "Pupil Diameter = " & pupilDiam & " mm" %]KOxaf_z  
~HM,@5dFC
 
    ' Calculate new parameters with accommodation usFhcU  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness fxcCz 5  
?h1r6?Sug{  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens )W0zu\fL =  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ;_TPJy  
0|L%)'F  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Iu=n$H  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ~4}'R_  
C8oAl3d+h  
    tlens = 3.767 + 0.04*A                  'Lens thickness 8s@k0T<O  
m7n8{J1O2  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction |s}7<A  
9Q.}jV  
    'Adjust parameters to account for accommodation k04CSzE"%  
@/yQ4Gr  
    '************************************************************************* o;^k"bo6  
    'Aqueous thickness (Position of Lens) :jP4GCxU|  
    '************************************************************************* $HE ?B{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'xn3g;5  
    GetCustomElement eID, entity \0'0)@uziQ  
j_#oP  
    parID = FindFullName( "Geometry.Arizona Eye" ) Zf [#~4  
^j)0&}fB  
    ' Delete any shift(s) in z FKVf_Ncf%
 
    count = 0 4^>FN"Ve`B  
    While GetOperationCount(eID)>count T=-$ok`G  
        GetOperation eID, count, op 2(%C  
        If op.Type="ShiftZ" Then :TTZ@
q  
            DeleteOperation eID,count !92zC._  
            count=count-1 Ic,V,#my  
        End If $Lf-Gi  
        count=count+1 fdCN?p[_  
    Wend u,f$c
R  
5Y}=,v*h}  
    'Set new shift in ] 1:p
nd  
    op.Type = "ShiftZ" !}$,) ~<+H  
    op.val1 = taq zo{WmV7[|  
    op.parent = parID $SAk|  
    AddOperation eID, op So^;5tG  
    Print "Set aqueous humor thickness = " & taq-0.55 A@H
Cd&h  
@4ECz>Q  
    '************************************************************************* ^|+;~3<J  
    'Radius and conic constant of anterior lens )K"7=TvY  
    '************************************************************************* sfuA {c'v  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) J-3%.fX,  
    GetConic eID, entity, curv, conic >kN%R8*Sx  
Qjl.O HO  
    SetConic eID, entity, 1/Rant, CCant _w\A=6=q|  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ,FP<# 0F*a  
D)my@W0,  
    '************************************************************************* { :~&#D  
    'Radius and conic constant of posterior lens 5[\LQtM  
    '************************************************************************* h,u?3}Knnb  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) {:!CA/0Jx  
    GetConic eID, entity, curv, conic teDO,
$  
8E:d!?<^&I  
    SetConic eID, entity, 1/Rpost, CCpost F\"`^`(O  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Bf-KCqC".  
l^,"^vz  
    '************************************************************************* j1Q"s(  
    'Lens thickness (Position of posterior lens surface) p\&Lbuzv  
    '************************************************************************* O,+ZD^  
P+j5_V{\b  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) <JyF5  
[ {|868  
    ' Delete any z-shift(s) F]4JemSjK  
    count = 0 iXJ3B&x  
    While GetOperationCount(eID)>count &qO#EEqG]  
        GetOperation eID, count, op JJ=%\j  
        If op.Type="ShiftZ" Then UOwEA9q%  
            DeleteOperation eID,count +l8`oQuG  
            count=count-1 UW?(-_8  
        End If BA 9c-Ay  
        count=count+1 q(C<w  
    Wend 0K*|B.O  
+YA,HhX9  
    'Set new z-shift g AZe&"K  
    op.Type = "ShiftZ" SJXA  
    op.val1 = tlens j$u=7Z&E  
    op.parent = parID m+ww  
    AddOperation eID, op "dN4EA
&QJ  
    Print "Set lens thickness = " & tlens wP: w8O  
-T0@b8  
    '************************************************************************* rbEUq.Yk]~  
    'Lens index of refraction /l)|
B  
    '************************************************************************* !eH9LRp  
    eID = FindMaterial( "Lens" ) R | &+g\{;  
    GetModelMaterial eID, mat U/|;u;H=  
!9/1_Bjv  
    mat.Nd = nlens erW[q  
    SetModelMaterial eID, mat J_H=GHMp}  
    Print "Set lens index of refraction = " & nlens
0OrT{jo  
;:/<XfZ  
    '************************************************************************* 8>KBh)q  
    'Pupil diameter {f9jK@%Gy  
    '************************************************************************* G+$A|'<`z  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) :nPLQqXGQ  
9AGf4tuy  
    'Adjust pupil diameter (trimming volume inner hole) 7 z#Xf  
\`!M5FJ  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :{YOJD
tR  
ox2?d<dC6  
    ' Adjust pupil location to just in front of the lens >Wbt_%dKy  
    parID = FindFullName( "Geometry.Arizona Eye" ) #go!"HL  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) sr*3uI-)L  
    count = 0 '0juZ~>}  
    While GetOperationCount(eID)>count 4 )U,A~!  
        GetOperation eID, count, op rz  
        If op.Type="ShiftZ" Then !|1GraiS  
            DeleteOperation eID,count k^vsQ'TD  
            count=count-1 T,sArKBI  
        End If iO 9fg  
        count=count+1 <1
L?Xhoc6  
    Wend aUBGp: (  
    op.Type = "ShiftZ" *u|bmt  
    op.val1 = taq-0.01 DAPbFY9  
    op.parent = parID )l|/lj  
    AddOperation eID, op )0Lno|l  
aIA
9rn  
    Print "Set pupil diameter = " & pupilDiam E`DsRR <  
b\dzB\,&  
    'Update AZ Eye subassembly Description *&m{)cTs  
    eID = FindFullName( "Geometry.Arizona Eye" ) )<vU F]e~  
    GetEntity eID, entity @ z{E  
    entity.Description = "Accommodation = " & A & "D" <DM /"^*  
    SetEntity eID, entity g
iDe  
!='?+Ysxs  
    Update |K H&,  
    Print "DONE!" (eOzntp8  
     vwlPFrLl  
End Sub 
G/w&yd4  
vuOixAkw  
如果屈光度是4，光瞳直径是4，则会输出如下数据： |Zn|?#F  
xux
j
 
Accommodation = 4 Diopters CfSpwkg  
Pupil Diameter = 4 mm %s^2m"ca}=  
Set aqueous humor thickness = 2.81 .sO.Y<-fl  
Set anterior lens radius = 10.4 and conic constant = -2.375869 \R6D'Yt  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 _aR_[  
Set lens thickness = 3.927 
ex-0@  
Set lens index of refraction = 1.42672 ncGg@$E  
Set pupil diameter = 4 ?(up!3S'x  
DONE! |#6B<'e'