[技术]Arizona眼睛模型 [复制链接]

简介 ~7;AV(\%e  
/TEE<\"  
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。 *@+E82D  
g.,_
E4L  
模型 =PM6:3aKh  
Y'&rSHI"  
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。 wk9qyv<  
$R&K-;D/8  
pB;8yz=  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. YP4lizs.  
%96l(JlJ)B  
光源 9YQYg@+R  
r,8~qHbOT  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 W ])Lc3X  
:P/0"  
T8t_+|( G  
HSG7jC'_  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 bc3 T8(  
]tsp}M@  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 `
z1E]{A  
Neb")  
; 8B)J<y  
v!WkPvU  
视网膜的散射 sZh| <2  
Fi8#r)G.  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 GNX`~%3KYc  
/RBIZ_  
;!:@3c  
0 zn }l6OS  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 qBDhCE  
jccSjGX@w  
=N^j:t  
:p
w6#yi8`  
脚本 T`W37fz0  
., =\/ C<  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： g^)8a;/c  
XCyAt;neon  
o?`^ UG-  
2]'cj  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 njGZ#{"eC  
余下的脚本计算与屈光度有关的所有参数。 L)QAI5o:3  
LB\+*P6QM  
分析 AYHefAF<w  
g!
I0UAm  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Wagb|B\  
Mh"vH0\Lj  
&]S\GnqlU]  
脚本代码 "NvB@>S  
L IN$Y  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. _%@ri]u{ov  
\H{UJ  
Dim entity As T_ENTITY #
McX  
Dim op As T_OPERATION X*< !_3  
Dim mat As T_MODELMATERIAL /#Lm)-%G  
Dim A As Double 5c 69M5  
Dim pupilDiam As Double /D,<2>o  
Dim eID As Long $TY1'#1U;  
Dim parID As Long M-zqD8D  
Dim count As Integer FB }8  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double u!TMt8+c  
Dim tlens As Double, nlens As Double /7&WFCc)(  
Dim curv As Double, conic As Double nq 9{{oe  
Dim ok As Long a"!r]=r  
=v6qr~  
Sub Main $^5c8wT  
il~A(`+YO  
    '用户输入对话框 <G /a-
Z  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 W0\ n?$ZC~  
        TextBox 220,21,40,21,.TextBox1 'default: 0 8],tGMu  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #<81`%  
        OKButton 40,91,90,21 f"aqg/l  
        CancelButton 190,91,90,21 @,;VMO  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 I`uOsZBO/  
        TextBox 220,49,40,21,.TextBox2 'default: 4 fDrjR6xV  
    End Dialog v@Bk)Z  
    Dim dlg As UserDialog k{E!X  
Rd,5&X$  
    ok = Dialog (dlg) R=<uf:ca  
tE]Y=x[Ux  
    If ok=0 Then    'cancel button was pressed UUR` m  
        Print "Execution cancelled." -m_H]<lWZ  
        End {33B%5n"  
    End If DpvMY94Qh  
`s~[q  
    'Assign accommodation and pupil diameter & use defaults if field left empty <]'1YDA
 
    If dlg.TextBox1 = "" Then DlxL:  
        A = 0           'Default accommodation jPmp=qg"q  
    Else nRh.;G  
        A = CDbl(dlg.TextBox1) Z>_F
:1x
 
    End If eK =v<X  
Fh~ pB>t  
    If dlg.TextBox2 = "" Then [KNA5(Y0  
        pupilDiam = 4   'Default pupil diameter 2<TpNGXM_  
    Else `8b4P>';O'  
        pupilDiam = CDbl(dlg.TextBox2) p{w:^l(  
    End If nrJW.F]S8[  
9e0t  
    Print " " !d{Ijs'T  
    Print "Accommodation = " & A & " Diopters" ^wMZG'/  
    Print "Pupil Diameter = " & pupilDiam & " mm" iE* Y@E5x0  
ldRisL  
    ' Calculate new parameters with accommodation wG",Obja  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness (x1 #_~  
uTRFeO>  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Vy@0Got5=  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens sO0j!;N  
04@?Jb1*  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Nz
G] nsw  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Cd'K~Ch3  
K yDPD'  
    tlens = 3.767 + 0.04*A                  'Lens thickness f#| wb~  
%d2\4{{S  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction aSQvtv)91  
!"s~dL,7  
    'Adjust parameters to account for accommodation B;^YHWJ6i  
aJSBG|IC  
    '************************************************************************* V@`A:Nc_>  
    'Aqueous thickness (Position of Lens) Hi#f Qji  
    '************************************************************************* <gjA(xT5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5v5K}hx  
    GetCustomElement eID, entity LNI]IITx/  
?vV&tqnx%  
    parID = FindFullName( "Geometry.Arizona Eye" ) r"=6s/q7  
_OvIi~KW+  
    ' Delete any shift(s) in z z1m$8-4  
    count = 0 ?f4jqF~Fh  
    While GetOperationCount(eID)>count 1 2J#}|  
        GetOperation eID, count, op N\W
4LO6  
        If op.Type="ShiftZ" Then k?qd -_sC  
            DeleteOperation eID,count Or"+d 5  
            count=count-1 zi= gOm  
        End If s#%P9A  
        count=count+1 =6< Am  
    Wend "Is0:au+?}  
+~!\;71:f  
    'Set new shift in Ct0YwIR*  
    op.Type = "ShiftZ" TY]-L1$  
    op.val1 = taq o 76QQ+hP  
    op.parent = parID 4NRG{FZ9  
    AddOperation eID, op g<jgR*TE`  
    Print "Set aqueous humor thickness = " & taq-0.55 EbMG9  
lWWy|r'il  
    '************************************************************************* !y-,r4\@`  
    'Radius and conic constant of anterior lens wfrSI:+>  
    '************************************************************************* JQk][3Rv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) >SaT?k1E  
    GetConic eID, entity, curv, conic ;}QM#5Xdt  
2; ~jKR[~  
    SetConic eID, entity, 1/Rant, CCant 3FE=?Q  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant jZP~!q  
iw0|A  
    '************************************************************************* UQ.DKUg  
    'Radius and conic constant of posterior lens >Z!H9]f(  
    '************************************************************************* Nk@ag)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) {p)=#Jd`.P  
    GetConic eID, entity, curv, conic 8bW,.to(?x  
y5$AAas  
    SetConic eID, entity, 1/Rpost, CCpost sq1v._^s  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ^>tqg^  
Xi"<'E3_  
    '************************************************************************* KdU&q+C^  
    'Lens thickness (Position of posterior lens surface) ,'^^
OLez  
    '************************************************************************* oV=~Q#v  
8 rA'd  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {>8u/  
hH*/[|z  
    ' Delete any z-shift(s) 4j VFzO%.  
    count = 0 #SIIhpjA(  
    While GetOperationCount(eID)>count :+$/B N:iO  
        GetOperation eID, count, op >TB Rp,;r  
        If op.Type="ShiftZ" Then xa$p,_W:'  
            DeleteOperation eID,count O[v(kH'  
            count=count-1 _MST8  
        End If s7G!4en  
        count=count+1 M?m)<vMr*  
    Wend 2%gLq  
d|RDx;rl8  
    'Set new z-shift i)mQ?Y#o  
    op.Type = "ShiftZ" e!.r- v9  
    op.val1 = tlens E!}~j  
    op.parent = parID d;WXlE;  
    AddOperation eID, op o.M.zkP a  
    Print "Set lens thickness = " & tlens *7:HO{P>Y  
8CN~o|uN  
    '************************************************************************* C Ch38qBp  
    'Lens index of refraction {((|IvP`  
    '************************************************************************* MaQ`7U5 |e  
    eID = FindMaterial( "Lens" ) XX;MoE~MM  
    GetModelMaterial eID, mat `vj"HhC  
d>r_a9 .u  
    mat.Nd = nlens 6$_//  
    SetModelMaterial eID, mat v dR6y  
    Print "Set lens index of refraction = " & nlens QZ^P2==x  


)7TuV"  
    '************************************************************************* pG0Ca](  
    'Pupil diameter ,!'L~{  
    '************************************************************************* KQv97#n1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) mb_~ "}A  
g_2EH
  
    'Adjust pupil diameter (trimming volume inner hole) |*[#Iii'  
cBz_L"5vr[  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _7qGo7bpN  
<QZ X""  
    ' Adjust pupil location to just in front of the lens l d
@B  
    parID = FindFullName( "Geometry.Arizona Eye" ) "5@k\?x"  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) fx`oe  
    count = 0 f )K(la^'  
    While GetOperationCount(eID)>count l7M![Ur  
        GetOperation eID, count, op f{j(H?5  
        If op.Type="ShiftZ" Then JMIS*njq^  
            DeleteOperation eID,count >wJt# ZB  
            count=count-1 3I%F,-r  
        End If n\G88)Dv`V  
        count=count+1 8 DE%ot  
    Wend cW*p
}hD  
    op.Type = "ShiftZ" 9]^ CD
L  
    op.val1 = taq-0.01 #V:28[  
    op.parent = parID sUEvL(%nY  
    AddOperation eID, op whdoG{/
  
Z{gJm9  
    Print "Set pupil diameter = " & pupilDiam p@Ng.HE  
 Lkl+f~m  
    'Update AZ Eye subassembly Description ]f<H?  
    eID = FindFullName( "Geometry.Arizona Eye" ) <sNkyQ  
    GetEntity eID, entity R;2q=%  
    entity.Description = "Accommodation = " & A & "D" hfQx$cv6  
    SetEntity eID, entity 4(O;lVT}  
w,qYT-R  
    Update x8q3 Njr

 
    Print "DONE!" A(dWAe,  
     k),!%6\(  
End Sub LtIw{*3  
pk5
W!K  
如果屈光度是4，光瞳直径是4，则会输出如下数据： tP;^;nw  
[sF z ;Py]  
Accommodation = 4 Diopters }'
.k  
Pupil Diameter = 4 mm ZlxJY%oeu  
Set aqueous humor thickness = 2.81 s)<^YASg  
Set anterior lens radius = 10.4 and conic constant = -2.375869 @%}4R`S0  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 cm!|A)~  
Set lens thickness = 3.927 ,j|9Bs  
Set lens index of refraction = 1.42672 %e,X7W`'2  
Set pupil diameter = 4 u{SJ#3C5  
DONE! B]-~hP