[技术]Arizona眼睛模型 [复制链接]

简介 bz@4obRqf  
{pVD`#Tl[  
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。 `.n[G~*w~1  
r8mE   
模型 $ _ gMJ\{  
ruoiG?:T  
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。 UXd\Q''  
Ji=E 1R  
zU(U^
 
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. q*2ljcb55  
uvT]MgT
  
光源 ?R";EnD  
3o6N&bQ b  
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。 ~(}zp<e|  
zdr?1=  
ifuVVFov  
%hY+%^k.  
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。 &D/_@\ 0  
TK'(\[E  
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。 eI- ~ +.  
)4j#gHN\  
 pCv=rK@  
$AoN,B>  
视网膜的散射 @}#$<6|  
Ix"uk6 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。 U:ZklDW  
Nhs]U`s(g  
Dk:Zeo]+my  
-BR&b2  
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。 ^/
c&Ud  
dw'%1g.113  
"",V\m  
w+PbT6;  
脚本 O GSJR`yT  
7)~/`w)P  
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： NFsMc0{  
&AC-?R|Dp  
%T!UEl`v  
x2;92I{5C,  
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。 ^oM*f{9  
余下的脚本计算与屈光度有关的所有参数。 C%l~qf1n  
'R= r9_%  
分析 6X)8vQH  
EY':m_7W  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 IeE+h-3p  
]x! vPIyq  
jP
hOk>m  
脚本代码 (m})V0/`  
BT>8  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. W +C\/  
!\^c9Pg|v  
Dim entity As T_ENTITY -49OE*uF  
Dim op As T_OPERATION v$lP?\P;}X  
Dim mat As T_MODELMATERIAL dX` _Y  
Dim A As Double az\;D\\  
Dim pupilDiam As Double #NwlKZ-  
Dim eID As Long
U_Id6J]8  
Dim parID As Long [[ HXOPaV  
Dim count As Integer ^<7)w2ns  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double $GPenQ~},  
Dim tlens As Double, nlens As Double $wAVM/u&  
Dim curv As Double, conic As Double Jy{A1i@4~s  
Dim ok As Long XV]`?  
i e%ZX  
Sub Main d2Bn`VI  
0~Z2$`(  
    '用户输入对话框 =2# C{u.  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 b2duC  
        TextBox 220,21,40,21,.TextBox1 'default: 0 9-
I;'  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 :^%My]>T  
        OKButton 40,91,90,21 pO4}6\1\  
        CancelButton 190,91,90,21 mq do@  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 JmtU>2z\
 
        TextBox 220,49,40,21,.TextBox2 'default: 4 /&Khk #  
    End Dialog R@u6mMX{N,  
    Dim dlg As UserDialog x4Y+?2  
7{2knm^  
    ok = Dialog (dlg) vH9/}w2  
 0'%R@|  
    If ok=0 Then    'cancel button was pressed :TxfkicN\  
        Print "Execution cancelled." eZk [6H  
        End X2/
`EN\  
    End If KzG8K 6wZ  
/k l0(='  
    'Assign accommodation and pupil diameter & use defaults if field left empty ~W_m<#K(  
    If dlg.TextBox1 = "" Then Q9]7.^l  
        A = 0           'Default accommodation VrrCW/o  
    Else :DCj2"  
        A = CDbl(dlg.TextBox1) y/
'2WO[  
    End If 0,{Dw9W:  
HFB2ep7N  
    If dlg.TextBox2 = "" Then Zm4IN3FGLv  
        pupilDiam = 4   'Default pupil diameter bo4 :|Z  
    Else [j`It4^nC  
        pupilDiam = CDbl(dlg.TextBox2) i\XOk!  
    End If uL1e
?  
3W5|Y@0  
    Print " " pdngM8n  
    Print "Accommodation = " & A & " Diopters" GTyS8`5E*  
    Print "Pupil Diameter = " & pupilDiam & " mm" 1.4]T, `  
{ %vX/Ek  
    ' Calculate new parameters with accommodation ~6Vs>E4G  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness (&=-o(  
Eo!1 WRruF  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens TwqyQ49  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 4w}\2&=  
.R#p<"$I  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens )
0 .
gW  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens MMN2X
xS  
@(,k%84z  
    tlens = 3.767 + 0.04*A                  'Lens thickness VrD?[&2pE  
?54=TA|5`F  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction #KF:(2  
kOmTji7  
    'Adjust parameters to account for accommodation wm}6$n?Za  
TxoMCN?7c  
    '************************************************************************* nw+L _b  
    'Aqueous thickness (Position of Lens) U}x2,`PI  
    '************************************************************************* Ia=wf"JS)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0m(/hK  
    GetCustomElement eID, entity 
Xai ,  
cZuZfM
DM  
    parID = FindFullName( "Geometry.Arizona Eye" ) <x,u!}5J  
x$Ko
|:-  
    ' Delete any shift(s) in z &cV$8*2b^  
    count = 0 cpF\^[D  
    While GetOperationCount(eID)>count iW(HOsA  
        GetOperation eID, count, op M}k )Ep9  
        If op.Type="ShiftZ" Then 9OuK}Ssf  
            DeleteOperation eID,count s4<[f%^  
            count=count-1 2Vxr  
        End If N)K};yMf  
        count=count+1 <*3{Twa1T  
    Wend B.-5$4*s  
Kn SXygT  
    'Set new shift in gbL99MZ@~  
    op.Type = "ShiftZ" (YVl5}V  
    op.val1 = taq OmQSNU.our  
    op.parent = parID BC ]^BKP
 
    AddOperation eID, op hZ Gr/5f  
    Print "Set aqueous humor thickness = " & taq-0.55 2f9~:.NgF  
#O6SEK|Z  
    '************************************************************************* &PI}o  
    'Radius and conic constant of anterior lens $Q{)AN;m  
    '************************************************************************* rk*Igqf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) .Qg!_C  
    GetConic eID, entity, curv, conic 7h?PVobe  
Z$ Fh4  
    SetConic eID, entity, 1/Rant, CCant "IA[;+_"  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !MSz%QcO  
PX65Z|~>_  
    '************************************************************************* <6Q]FH!6  
    'Radius and conic constant of posterior lens "#z4  
    '************************************************************************* PwU}<Hrl]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) r483"k(7  
    GetConic eID, entity, curv, conic y:WRpCZoa  
060<wjX6  
    SetConic eID, entity, 1/Rpost, CCpost JP)/ O!  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #Z;ziM:  
v%n'_2J =^  
    '************************************************************************* 3Q*K+(`{  
    'Lens thickness (Position of posterior lens surface) 4Z)`kS}=]  
    '************************************************************************* /Mb?dVwA  
\u?z:mV  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) U>7"BpC  
[7q~rcf,Z  
    ' Delete any z-shift(s) 3P3x^NI  
    count = 0 XeX0\L')R  
    While GetOperationCount(eID)>count fIN8::Cs[  
        GetOperation eID, count, op '31pb9@fH  
        If op.Type="ShiftZ" Then ny%-u&1k  
            DeleteOperation eID,count 3Wxl7"!x m  
            count=count-1 "2;$?*hO#  
        End If b)J(0,9`G"  
        count=count+1 ~z#Faed=a  
    Wend an={h,  
m:5*:Ii.  
    'Set new z-shift #qWa[k
B  
    op.Type = "ShiftZ" fp|!LU  
    op.val1 = tlens \!j{&cJ  
    op.parent = parID XmXp0b7  
    AddOperation eID, op &1YAPxX  
    Print "Set lens thickness = " & tlens XKN`{h-@  
8.HqQ:?&2t  
    '************************************************************************* cG1-.,r  
    'Lens index of refraction {c`kC]9  
    '************************************************************************* mwVH>3{j  
    eID = FindMaterial( "Lens" ) C9`#57Pp  
    GetModelMaterial eID, mat pm$,B7Q`oO  

kKAK;JQ  
    mat.Nd = nlens ,pE{N&p9  
    SetModelMaterial eID, mat " NnUu8x  
    Print "Set lens index of refraction = " & nlens li;Np5P  
"^VKs_U8o  
    '************************************************************************* KArt4+31  
    'Pupil diameter cJj4qXF  
    '************************************************************************* 3$[!BPLFO  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) )%Z<9k  
T5?@'b8F6  
    'Adjust pupil diameter (trimming volume inner hole) NF&R}7L  
unKTa*U^q  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" a<7Ui;^@  
eE5U|y)_  
    ' Adjust pupil location to just in front of the lens hd1(q33  
    parID = FindFullName( "Geometry.Arizona Eye" ) <
iVn!P  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) YA9Xe+g  
    count = 0 fvK):eCo  
    While GetOperationCount(eID)>count
Tm~a&p  
        GetOperation eID, count, op .P+om<~B  
        If op.Type="ShiftZ" Then |S[Gg  
            DeleteOperation eID,count RhIRCN9  
            count=count-1 H(9%SP@[c  
        End If S]mXfB(mh  
        count=count+1 Q laz3X,P  
    Wend .)~IoIW=  
    op.Type = "ShiftZ" 37Ux2t  
    op.val1 = taq-0.01 AeR3wua  
    op.parent = parID FB-?{78~  
    AddOperation eID, op `K37&b;`[  
IoWh&(+KdH  
    Print "Set pupil diameter = " & pupilDiam CIAHsbn.A  
aal5d_Y  
    'Update AZ Eye subassembly Description oV"#1
lp*  
    eID = FindFullName( "Geometry.Arizona Eye" ) Uu ~BErEC  
    GetEntity eID, entity 6=A
  
    entity.Description = "Accommodation = " & A & "D" H"lq!C`  
    SetEntity eID, entity rKg~H=4x2  
^[6eo8Ck>  
    Update U86bn(9K  
    Print "DONE!" Y1?wf.  
     L]
I ;{Y  
End Sub ]pr(hk  
_1_CYrUc  
如果屈光度是4，光瞳直径是4，则会输出如下数据： ,?g}->ZB  
{#"[h1  
Accommodation = 4 Diopters >KXSb@  
Pupil Diameter = 4 mm ^x(BZol
km  
Set aqueous humor thickness = 2.81 A+v6N>}*  
Set anterior lens radius = 10.4 and conic constant = -2.375869 uz-O%R-  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 mTXeIng?  
Set lens thickness = 3.927 |^p7:)cy  
Set lens index of refraction = 1.42672 >8h14uCk  
Set pupil diameter = 4 S_?{<{  
DONE! )Zud|%L