[技术]Arizona眼睛模型 [复制链接]

简介 C+uW]]~I)  
$:%E<j4Dn  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 Y*$>d/E  
w8>h6x"  
模型 5e$1KN`  
);':aXj  
模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 tH)jEY9  
?"r=08  
iX6>u4~(  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. &n )MGg1%  
ZaU8eg7  
光源 *s*Y uY%y  
,bXZ<RY$  
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。 >iae2W`
 
chKK9SC+|  
y7M{L8{0  
e~'lWJD  
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。 ?T2>juf]5~  
E#!!tH`lgg  
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。 ^\AeX-q2v'  
.dk<?BI#H  
m<hP"j  
m9oOH5@K~  
视网膜的散射 EM*I%|n@m  
/V:9*C  
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。 NDP" @  
:${tts2g  
Q0Ft.b  
H#_Zv]  
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。 0mujf  
 d(o=)!p  
![^pAEgx  
~_vSMX
 
脚本 \jtA8o%n  
zo(#tQ-'m  
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： OALNZKP  
2Q
p}f^  
h9)fXW
 
\4q|Qno8  
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。 RkYn6  
余下的脚本计算与屈光度有关的所有参数。 Q2VF+g,  
teg5g|*  
分析 G n]qh(N>  
CpO_p%P  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Zk%@GOu\  
Z5>~l  
}+9?)f{?@  
脚本代码 SlG v  
Kd
`(^  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. 'd+fGx7i  
Mq
nUym  
Dim entity As T_ENTITY N $) G8  
Dim op As T_OPERATION <bKtAf  
Dim mat As T_MODELMATERIAL >#|%'Us  
Dim A As Double ]=00<~ l*q  
Dim pupilDiam As Double [j+:2@  
Dim eID As Long I "AjYv4R  
Dim parID As Long IC0L&;En  
Dim count As Integer xmv%O&0^}  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ;7lON-@BI  
Dim tlens As Double, nlens As Double |6*Bu1  
Dim curv As Double, conic As Double CJ\a7=*i  
Dim ok As Long )x|;%.8FX7  
{h?pvH_>  
Sub Main XMuZ
}u[U  
t]LiFpy2IC  
    '用户输入对话框 ^HSxE  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 [CI&4)#  
        TextBox 220,21,40,21,.TextBox1 'default: 0 J:m/s9r  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~?F,kmO}?  
        OKButton 40,91,90,21 ETdXk&AN  
        CancelButton 190,91,90,21 i)o;,~ee  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 !CGX\cvW  
        TextBox 220,49,40,21,.TextBox2 'default: 4 K3?5bT_{  
    End Dialog VGV-t  
    Dim dlg As UserDialog zeHF-_{  
lGd'_~'=  
    ok = Dialog (dlg) 7AV{ h[J  
KNx/1lf  
    If ok=0 Then    'cancel button was pressed zuvPV{ X  
        Print "Execution cancelled." zqeQ  
        End $Z@*!B^  
    End If hC<ROD  
_uQ]I^'D  
    'Assign accommodation and pupil diameter & use defaults if field left empty Hb=#`  
    If dlg.TextBox1 = "" Then #d-({blo<  
        A = 0           'Default accommodation y&NqVR=  
    Else nje7?Vz  
        A = CDbl(dlg.TextBox1) ~Ru\Z-q1  
    End If 4X
N \p  
)d2Z g  
    If dlg.TextBox2 = "" Then $o[-xNn1  
        pupilDiam = 4   'Default pupil diameter +/ukS6>gr  
    Else =0)|psCsM  
        pupilDiam = CDbl(dlg.TextBox2) r
Vz.Ws#  
    End If C}8#yAS9M  
aA`eKy) \  
    Print " " +:FXtO>n"  
    Print "Accommodation = " & A & " Diopters" :;+!ID_
  
    Print "Pupil Diameter = " & pupilDiam & " mm" NIV}hf YF  
4D?h}U /  
    ' Calculate new parameters with accommodation !mNst$-H4  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness C*Vm}|)  
3V
k8'  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens VE )D4RL  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 3(BL  
'c3
5%?]  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens T
2e-RR  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens (T%F^s5D  
KL&/Yt  
    tlens = 3.767 + 0.04*A                  'Lens thickness s@\3|e5g  
v)5;~.+%  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction vzIo2,/7  
tu -a`h_NJ  
    'Adjust parameters to account for accommodation ,h*gd^i  
n7!T{+ge  
    '************************************************************************* $plk>Khg  
    'Aqueous thickness (Position of Lens) .|,LBc!  
    '************************************************************************* mfraw2H  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >]h{[kU %4  
    GetCustomElement eID, entity )CFJXc:  
*qpu!z2m||  
    parID = FindFullName( "Geometry.Arizona Eye" ) Cj0r2^`  
C>Ik ;  
    ' Delete any shift(s) in z -<g9) CV5  
    count = 0 qed_PsI  
    While GetOperationCount(eID)>count a~_9BM41T  
        GetOperation eID, count, op 7'\.QJ!<  
        If op.Type="ShiftZ" Then =3bk=vy  
            DeleteOperation eID,count kF|$oBQ  
            count=count-1 Px_8lB/;  
        End If Ng#psN  
        count=count+1 !<w6j-S  
    Wend :\;9y3  
I-#!mFl  
    'Set new shift in L ]')=J+  
    op.Type = "ShiftZ" DsdM:u*s  
    op.val1 = taq yq~  
    op.parent = parID '}hSh  
    AddOperation eID, op !:+U-mb*  
    Print "Set aqueous humor thickness = " & taq-0.55
Thggas,  
o-<i+To%  
    '************************************************************************* {Ydhplg{  
    'Radius and conic constant of anterior lens 5Q10O
hh  
    '************************************************************************* :w^:Z$-hf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) \]
x`f3F  
    GetConic eID, entity, curv, conic LK h=jB^bT  
0F$|`v"0  
    SetConic eID, entity, 1/Rant, CCant 534pX7
dg  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant t#(NfzN  
2"6L\8hd2  
    '************************************************************************* @fd<  
    'Radius and conic constant of posterior lens Z!v,;MW  
    '************************************************************************* #]Vw$X_S  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) WAn@8!9  
    GetConic eID, entity, curv, conic !{&r|6  
2f(`HSC'  
    SetConic eID, entity, 1/Rpost, CCpost +wQ5m8E  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost N<JI^%HBgP  
SqAz((  
    '************************************************************************* I"]E}nd)  
    'Lens thickness (Position of posterior lens surface) 2tz4Ag  
    '************************************************************************* u$w.'lK  
whI4@#  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) -l=C7e  
U`*we43  
    ' Delete any z-shift(s) ihkZs3}  
    count = 0 .\bJ,of9  
    While GetOperationCount(eID)>count IR/S`HD_  
        GetOperation eID, count, op xbiprhdv  
        If op.Type="ShiftZ" Then :lu!%p<$  
            DeleteOperation eID,count |1wZ`wGZ:L  
            count=count-1 UB@(r86d  
        End If {JWixbA  
        count=count+1 i?_Q@uA~<:  
    Wend o9sQ!gptw  
b8a(.}8*  
    'Set new z-shift i7H([b<_m  
    op.Type = "ShiftZ" n
[/D>Pi  
    op.val1 = tlens rT="ciQ  
    op.parent = parID B+FTkJ0t+G  
    AddOperation eID, op t(}Y/'  
    Print "Set lens thickness = " & tlens 5T/+pC$e=  
$;g*s?F*  
    '************************************************************************* D u<P^CE  
    'Lens index of refraction 55v=Ij?M  
    '************************************************************************* Z@q1&}D!  
    eID = FindMaterial( "Lens" ) xEG:KSH  
    GetModelMaterial eID, mat H8HH) ^  
 5+GTK)D  
    mat.Nd = nlens 0Cc3NNdz  
    SetModelMaterial eID, mat [
]OS p&  
    Print "Set lens index of refraction = " & nlens S> Fb'rJ3  
OBFM70K  
    '************************************************************************* R1*&rjB  
    'Pupil diameter NiG&Lw*8  
    '************************************************************************* aR6~r^jB  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ,>6mc=p  
8\il~IFyi  
    'Adjust pupil diameter (trimming volume inner hole) ~,W|i  
$jk4H+H-  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" i@{b+5$  
.t^1
e  
    ' Adjust pupil location to just in front of the lens &IQNsJL!e  
    parID = FindFullName( "Geometry.Arizona Eye" ) El}~3|a?  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) S?DMeZ{:  
    count = 0 6heK8*.T  
    While GetOperationCount(eID)>count =>*}qen  
        GetOperation eID, count, op k8Dk;N  
        If op.Type="ShiftZ" Then *4 m]UK  
            DeleteOperation eID,count Sn97DCdk  
            count=count-1 :4:U\k;QwA  
        End If 
KjA7x  
        count=count+1 $1X
!Ecq_  
    Wend ~Q- /O~  
    op.Type = "ShiftZ" KYhL}C+  
    op.val1 = taq-0.01 af'ncZ@U  
    op.parent = parID a#0*#&?7@  
    AddOperation eID, op *<9M|H~  
TbqtT_{  
    Print "Set pupil diameter = " & pupilDiam ][f0ZMa  
9aID&b+  
    'Update AZ Eye subassembly Description rp]H&5.*  
    eID = FindFullName( "Geometry.Arizona Eye" ) _J>Ik2EF  
    GetEntity eID, entity 2Z(?pJyDM  
    entity.Description = "Accommodation = " & A & "D" JWt
@vf~  
    SetEntity eID, entity Y(JZP\Tf_N  
j1JdG<n  
    Update ,[n=PJVw/  
    Print "DONE!" lz).=N}m  
     H2_6m5[&,  
End Sub b^Do
[o}5  
nCldH|>5w  
如果屈光度是4，光瞳直径是4，则会输出如下数据： ?r0>HvUf!l  
`=TJw,q  
Accommodation = 4 Diopters LNgFk%EH  
Pupil Diameter = 4 mm OoOwEV2p_  
Set aqueous humor thickness = 2.81 k%RQf0`T  
Set anterior lens radius = 10.4 and conic constant = -2.375869 [c>YKN2qa  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Kt#X'!9/<  
Set lens thickness = 3.927 eET1f8B=L  
Set lens index of refraction = 1.42672 -OQ6;A"#  
Set pupil diameter = 4 t-FrF</0  
DONE! %H"AHkge:a