首页 -> 登录 -> 注册 -> 回复主题 -> 发表主题
光行天下 -> 讯技光电&黉论教育 -> Arizona眼睛模型 [点此返回论坛查看本帖完整版本] [打印本页]

infotek 2021-10-22 09:55

Arizona眼睛模型

简介 ?jywW$   
!N4?>[E  
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。 : -@o3Syg  
I/ pv0  
模型 Z|YiYQl[)  
n\Z& sc  
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。 &ACM:&Ob  
!5rja-h  
Table 1. AZ眼睛模型的定义
D\~*| J  
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. lNcXBtwK@#  
1M|DaAI  
光源 *&b~cyC  
dMAd-q5{  
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。 QRs!B!Fn0  
T@PtO "r  
\vBpH'hR,'  
图1. 光源和提示信息使用
S7cxEOfAu  
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。 6m_whGosi  
ORPQ1%tu  
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。 S!0ocS!t  
wl1JKiodg  
图2. 字母F光源的设定方法光 %Lec\(-4L  
$V$|"KRcs  
图3. 字母F在视网膜上位置点列图
n3, ?klK  
视网膜的散射 :NL.#!>/  
6~Y-bn"%D5  
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。 gl/n*s#r_  
zG_e=   
;dt&* ]wA  
图4. 视网膜朗伯散射设定
xP<cF  
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。 F&r+"O)^-R  
WN?1J4H  
hcEU kD  
图5. 视网膜重点采样规格设定
V 0Ul`  
脚本 :IFTiq5a;  
rs$sAa*f  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: #87:Or1  
~c7}eTJd"  
图6. 用户对话框的创建与编辑
KQ<pQkhv  
图7. 用户对话框编辑器
^|DI9G(Bs  
如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 tp2CMJc{L  
余下的脚本计算与屈光度有关的所有参数。 {l= !  
WAlsh  
分析 M$L1!o1Xf  
"=I ioY  
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@ jW&-;  
L*tn>AO  
图7. 字母F在视网膜上颜色分析
T_CYSS|fX  
脚本代码 $FEG0&  
:(EU\yCzK  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. kQXtO)  
rt] @Z`w  
Dim entity As T_ENTITY 7-81,ADv(  
Dim op As T_OPERATION kKnz F  
Dim mat As T_MODELMATERIAL k WYjqv  
Dim A As Double >IO}}USm  
Dim pupilDiam As Double 9,y*kC  
Dim eID As Long kBd #=J  
Dim parID As Long ) 'x4#5]  
Dim count As Integer $-9m8}U(Y  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double SEQ bw](ss  
Dim tlens As Double, nlens As Double (NUwkAO M}  
Dim curv As Double, conic As Double 3e$&rpv  
Dim ok As Long /)?]vKMiI  
('!90  
Sub Main {'8a' 9\  
M H }4F  
    '用户输入对话框 H"f%\'  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 rJK3;d?E  
        TextBox 220,21,40,21,.TextBox1 'default: 0 weC$\st:D  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 D^P_3 B+  
        OKButton 40,91,90,21 E7^r3#s  
        CancelButton 190,91,90,21 iF2/:iP  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 X<J NwjM%  
        TextBox 220,49,40,21,.TextBox2 'default: 4 |) QE+|?P  
    End Dialog ,6?L.L  
    Dim dlg As UserDialog hp6S *d  
gl-O"%rMcL  
    ok = Dialog (dlg) 'VCF{0{H~  
XPE{]4 g  
    If ok=0 Then    'cancel button was pressed '~A~gK0  
        Print "Execution cancelled." NK'awv),pM  
        End y)?Sn  
    End If lCg'K(|"  
?cf9q@eAH  
    'Assign accommodation and pupil diameter & use defaults if field left empty rmutw~nHD  
    If dlg.TextBox1 = "" Then [_ESR/&N  
        A = 0           'Default accommodation -sl] funRy  
    Else "#^11o8  
        A = CDbl(dlg.TextBox1) S{aK\>>H  
    End If \'6hv>W@  
!]7r>NS>  
    If dlg.TextBox2 = "" Then DU#6%8~  
        pupilDiam = 4   'Default pupil diameter [5^"U+`{x  
    Else /qA\|'~  
        pupilDiam = CDbl(dlg.TextBox2) 2:^Dv1J)rD  
    End If TG'_1m*$  
-4{sr| lm  
    Print " " DQY*0\  
    Print "Accommodation = " & A & " Diopters" WPiQ+(pt  
    Print "Pupil Diameter = " & pupilDiam & " mm" r`}')2  
7*]O]6rP  
    ' Calculate new parameters with accommodation _!kL7qJ"  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness m[,! orq  
 U=MFNp+  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens rI)op1K  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens gq4le=,v  
smW 7zGE  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens }N!I|<"/  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens @#$5_uU8\(  
\&|)?'8rS  
    tlens = 3.767 + 0.04*A                  'Lens thickness ntE;*F yH  
X*6bsYbK-  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction s0 hD;`cm  
8R}CvzI  
    'Adjust parameters to account for accommodation ,cD(s(6+  
E$dPu  
    '************************************************************************* 4JSf t t  
    'Aqueous thickness (Position of Lens) nE#p Ry]  
    '*************************************************************************  +T02AS  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) SbI %|  
    GetCustomElement eID, entity <m:8%]%M6  
ys|a ^VnN  
    parID = FindFullName( "Geometry.Arizona Eye" ) (mIw3d8Tz  
'H- : >'k  
    ' Delete any shift(s) in z aaW(S K  
    count = 0 tb#. Y  
    While GetOperationCount(eID)>count jFfuT9oId  
        GetOperation eID, count, op Ge=+ 0W)&  
        If op.Type="ShiftZ" Then ;LM`B^Q]s  
            DeleteOperation eID,count v:kTZB  
            count=count-1 "pGSz%i-  
        End If o8c4h<,  
        count=count+1 [`^5Zb  
    Wend 6jT+kq)  
;2 -%IA,  
    'Set new shift in !2>MaV1,  
    op.Type = "ShiftZ" O+hN?/>v  
    op.val1 = taq ` MtI>x c  
    op.parent = parID ^6tGj+D9  
    AddOperation eID, op L5 ~wX  
    Print "Set aqueous humor thickness = " & taq-0.55 V'y,{YpP  
/f2HZfj  
    '************************************************************************* ]p C/6'  
    'Radius and conic constant of anterior lens X;/~d>@  
    '************************************************************************* 70IBE[T&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) |c,,*^  
    GetConic eID, entity, curv, conic C,$$bmS =  
 <yE  
    SetConic eID, entity, 1/Rant, CCant _GSl}\  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant f&x7g.I  
_Eo$V&  
    '************************************************************************* i Qs7L y"  
    'Radius and conic constant of posterior lens = rDoXm  
    '************************************************************************* b`M  2VZu  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) . AJ(nJ)  
    GetConic eID, entity, curv, conic 1#BMc%  
;Gf,$dbWn  
    SetConic eID, entity, 1/Rpost, CCpost @ov*Fh  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ^i>Tm9vM  
#qqIOjS^w  
    '************************************************************************* z2:^Qg  
    'Lens thickness (Position of posterior lens surface) >p"ytRu^  
    '************************************************************************* l!z)gto  
tB-0wD=PR  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;la sk4|  
);X &J:-l+  
    ' Delete any z-shift(s)  vV5dW  
    count = 0 3 sUTdCnNf  
    While GetOperationCount(eID)>count 4O}ZnE1[  
        GetOperation eID, count, op ;A^Ii>`  
        If op.Type="ShiftZ" Then l0hcNEj{W  
            DeleteOperation eID,count XNODDH   
            count=count-1 Z{<&2*  
        End If UqJ}5{rt  
        count=count+1 _J' _9M?>  
    Wend PL*Mz(&bf  
i|5.DhK}  
    'Set new z-shift J0xV\O !e  
    op.Type = "ShiftZ" SvE3E$*  
    op.val1 = tlens <0R$yB  
    op.parent = parID `x b\)  
    AddOperation eID, op 9eG{"0)  
    Print "Set lens thickness = " & tlens :xqhPr]e  
UEkn@^&bg  
    '************************************************************************* X9ua&T2(l  
    'Lens index of refraction |%p;4b  
    '************************************************************************* tb#9TF  
    eID = FindMaterial( "Lens" ) B4fMD]  
    GetModelMaterial eID, mat `XT8}9z!  
V5ve  
    mat.Nd = nlens _[J @w.l(  
    SetModelMaterial eID, mat q6R``  
    Print "Set lens index of refraction = " & nlens =EE>QM  
[w>T.b  
    '************************************************************************* l~_] k  
    'Pupil diameter b A/,{R  
    '************************************************************************* Nu}x`Qkmr  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Kyn[4Bu!?  
x?5D>M/Y  
    'Adjust pupil diameter (trimming volume inner hole) G3Z>,"w;=  
yiourR)H<  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }K<% h  
I[P43>F3  
    ' Adjust pupil location to just in front of the lens V?_:-!NJ(  
    parID = FindFullName( "Geometry.Arizona Eye" ) cOhx  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) h`{agW B  
    count = 0 c)L1@qdZ  
    While GetOperationCount(eID)>count abs\Ku9  
        GetOperation eID, count, op yf 7Sz$Eq  
        If op.Type="ShiftZ" Then 45?aV@  
            DeleteOperation eID,count 6A$  Y]u  
            count=count-1 PIo8mf/  
        End If 0-s[S  
        count=count+1 397IbZ\  
    Wend SK6?;_  
    op.Type = "ShiftZ" whoM$  &  
    op.val1 = taq-0.01 KM'*+.I  
    op.parent = parID  ~OdE!!  
    AddOperation eID, op A(j9T,!  
|{STkV]  
    Print "Set pupil diameter = " & pupilDiam E2hy%y9Tp  
!Eqp,"ts7  
    'Update AZ Eye subassembly Description htgtgW9 ^P  
    eID = FindFullName( "Geometry.Arizona Eye" ) /=y _ #l  
    GetEntity eID, entity |o6g{#1  
    entity.Description = "Accommodation = " & A & "D" pUp&eH  
    SetEntity eID, entity 2cnyq$4k  
ftaGu-d%  
    Update vOF"p4 ^3  
    Print "DONE!" 0`=>/Wr39  
     PN(P$6  
End Sub k'(d$;Jgr  
1o Z!Up0  
如果屈光度是4,光瞳直径是4,则会输出如下数据: XA1gV>SJ  
tAi ~i;?  
Accommodation = 4 Diopters o.o$dg(r!  
Pupil Diameter = 4 mm m|/q o  
Set aqueous humor thickness = 2.81 Exu5|0AAE  
Set anterior lens radius = 10.4 and conic constant = -2.375869 `]T# uP<u  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ^9jrI  
Set lens thickness = 3.927 )qq5WShMJ  
Set lens index of refraction = 1.42672 b235Zm  
Set pupil diameter = 4 $vC}Fq  
DONE! n7>L&?N#y#  
查看本帖完整版本: [-- Arizona眼睛模型 --] [-- top --]

Copyright © 2005-2025 光行天下 蜀ICP备06003254号-1 网站统计