首页 -> 登录 -> 注册 -> 回复主题 -> 发表主题
光行天下 -> FRED,VirtualLab -> FRED运用：Arizona眼睛模型 [点此返回论坛查看本帖完整版本] [打印本页]

xunjigd 2016-02-24 12:53

FRED运用：Arizona眼睛模型

简介 %t{Sb4XZ4k  
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。 a+'}XEhSC:  
Z?C4a }  
模型 }bCK  
 V0S6M^\DK  
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。 'tut4SwC  
mCK],TOA:  
Table 1. AZ眼睛模型的定义
[attachment=67931]
'DeW<Sa~  
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. ]'6'<S  
qkiJ HT  
光源 OMi02tSm  
 +`9yZOaC#  
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。 5U3qr*/;m  
 e$H|MdYIA  
Mc!2mE%47m  
[attachment=67932]
图1. 光源和提示信息使用
{dZ!I  
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。 )G^p1o;\  
5d%_Wb'  
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。 |1lf(\T_  
{uEu >D$8  
[attachment=67933]
图2. 字母F光源的设定方法光 I7A7X*  
ypgliq(  
[attachment=67934]
图3. 字母F在视网膜上位置点列图
O(WEgz  
视网膜的散射 L,E-z_<p  
Z(l9>A7!  
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。 !~?W \b\:  
 ^dheJ]n=k  
$  9S>I'  
[attachment=67935]
图4. 视网膜朗伯散射设定
yB 1I53E  
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。 CQj/e+eE4  
 qK{| Q  
t) ;   
[attachment=67936]
图5. 视网膜重点采样规格设定
dko[  
脚本 Z@<q/2).|  
FP.(E9  
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： X@i+&Nv"<  
czXI?]gg,  
[attachment=67937]
图6. 用户对话框的创建与编辑
t^`<*H  
[attachment=67938]
图7. 用户对话框编辑器
qPp1:a"   
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。 jK& Nkp  
余下的脚本计算与屈光度有关的所有参数。 ^nG1/}  
(3)C_Z  
分析 (k7;  
 }~7H2d);-  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 $I?=.:<+  
pP?<[ql[w  
[attachment=67939]
图7. 字母F在视网膜上颜色分析
v]LFZI5  
脚本代码 U'JP1\  
{LR#(q$1  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. Hj}g1"RA  
?AqrlR]5  
Dim entity As T_ENTITY T=hm#]   
Dim op As T_OPERATION f 3nnXE"  
Dim mat As T_MODELMATERIAL J>,'P^  
Dim A As Double gJWlWVeq$  
Dim pupilDiam As Double mafAC73  
Dim eID As Long BDv|~NHs  
Dim parID As Long 8eg2o$k_,#  
Dim count As Integer n?TO!5RZK  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double $i1>?pb3  
Dim tlens As Double, nlens As Double ,*9#c*'S  
Dim curv As Double, conic As Double Yke<Wy1  
Dim ok As Long e#76h;  
|THkS@Br  
Sub Main R47I\{  
-y7l?N5F>  
    '用户输入对话框 $g}/T_26  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 +oxqS&$L  
        TextBox 220,21,40,21,.TextBox1 'default: 0 'ugR!o1  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 brp N >\  
        OKButton 40,91,90,21 "GIg| 3  
        CancelButton 190,91,90,21 s5_1}KKCs  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 *YiD B?Si  
        TextBox 220,49,40,21,.TextBox2 'default: 4 J.CZR[XF#  
    End Dialog OI;L9\MJc  
    Dim dlg As UserDialog _BeX7  
ynOc~TN  
    ok = Dialog (dlg) W2X+N acD  
X:zyzEhS  
    If ok=0 Then    'cancel button was pressed y$;zTH_6j  
        Print "Execution cancelled." YV2pERl  
        End IArpCF/"8  
    End If \k$]GK-  
]9~#;M%1  
    'Assign accommodation and pupil diameter & use defaults if field left empty !T&u2=`D  
    If dlg.TextBox1 = "" Then )nbyV a  
        A = 0           'Default accommodation MO(5-R`  
    Else 6i?kkULBS  
        A = CDbl(dlg.TextBox1) ] BP^.N=  
    End If 4F 6ju6w  
.[eSKtbc)  
    If dlg.TextBox2 = "" Then ej??j<]  
        pupilDiam = 4   'Default pupil diameter U 8 .0L  
    Else lzQ&)7`  
        pupilDiam = CDbl(dlg.TextBox2) @N:3`[oB  
    End If QKL]O*  
<T=o]M$  
    Print " " nu1w:  
    Print "Accommodation = " & A & " Diopters" |~T+f&   
    Print "Pupil Diameter = " & pupilDiam & " mm"  (t]R#2{  
+MZ2e^\F  
    ' Calculate new parameters with accommodation z;@S_0M,Z  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness H]]>sE  
O.m.]%URW  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [;kj,j  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens k?@W/}Iv9  
5"Xo R)  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens $(<*pU  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 6`{)p&9  
n$\6}\k  
    tlens = 3.767 + 0.04*A                  'Lens thickness v*T@ <]f3j  
*TMM:w|1  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction qgY(S}V  
| Y,X=Ed  
    'Adjust parameters to account for accommodation a6K$omu  
r%?}5"*  
    '************************************************************************* O'?lW~CD.>  
    'Aqueous thickness (Position of Lens) vA $BBXX  
    '************************************************************************* 8i+jFSZ$  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) l.t.,:  
    GetCustomElement eID, entity ?)ZLxLV::  
rBL_]\$7}  
    parID = FindFullName( "Geometry.Arizona Eye" ) 7[VCCI g  
MJk:s[o  
    ' Delete any shift(s) in z ?(XX  
    count = 0 lVK F^-i  
    While GetOperationCount(eID)>count [E&"9%K  
        GetOperation eID, count, op d`rDEa  
        If op.Type="ShiftZ" Then vN[m5)aT  
            DeleteOperation eID,count uc `rt"  
            count=count-1 r'}k`A 5>  
        End If Szob_IEq,  
        count=count+1 jq]\oY8y  
    Wend "q#g/T  
gcY~_'&u  
    'Set new shift in p RfHbPV?  
    op.Type = "ShiftZ" dYttse'  
    op.val1 = taq < oG\)!O  
    op.parent = parID v,O&UrZ  
    AddOperation eID, op PfMOc+ q  
    Print "Set aqueous humor thickness = " & taq-0.55 [ @71  
2LK*Cv[  
    '************************************************************************* {Eb2<;1o{  
    'Radius and conic constant of anterior lens ny;)+v?mN\  
    '************************************************************************* SF}L3/C&h  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) [ZpG+VAJ8  
    GetConic eID, entity, curv, conic t`/RcAwA  
w[7HY@[  
    SetConic eID, entity, 1/Rant, CCant "gVH;<&]  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant P xuz {  
oz7udY=]0  
    '************************************************************************* nT6iS}h  
    'Radius and conic constant of posterior lens "Kf~`0P  
    '************************************************************************* xn#I7]]G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) t7& GCZ  
    GetConic eID, entity, curv, conic MhXm-<4  
<UHf7:0V  
    SetConic eID, entity, 1/Rpost, CCpost o]k]pNO  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ~V)VGGOL$v  
K>E!W!-PJ  
    '************************************************************************* ,}$x'8v  
    'Lens thickness (Position of posterior lens surface) jF2GHyB  
    '************************************************************************* !)1Zp*  
)qQg n]  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) h.0&)t\q"  
dtXJ<1:  
    ' Delete any z-shift(s) <i @jD  
    count = 0 <\Dl#DH  
    While GetOperationCount(eID)>count k.VOS 0  
        GetOperation eID, count, op o".O#^3H%  
        If op.Type="ShiftZ" Then rY+1s^F  
            DeleteOperation eID,count T_ #oMXZ/  
            count=count-1 iK23`@&% _  
        End If JN|#   
        count=count+1 Tp.iRFFkP  
    Wend Z#t.wWSq  
=Qq^=3@h  
    'Set new z-shift 00 ,j neF  
    op.Type = "ShiftZ" @Pg@ltUd  
    op.val1 = tlens 23?0'AU  
    op.parent = parID ?d'9TOlD  
    AddOperation eID, op :9< r(22  
    Print "Set lens thickness = " & tlens L{ ^@O0S  
"+C\f)  
    '************************************************************************* M/I d\~  
    'Lens index of refraction \r&@3a.>  
    '************************************************************************* !!pi\J?sk  
    eID = FindMaterial( "Lens" ) / =<u l-K  
    GetModelMaterial eID, mat +=xRr?F  
DccsVR`7  
    mat.Nd = nlens Q(Y,p`>  
    SetModelMaterial eID, mat z-E4-\a  
    Print "Set lens index of refraction = " & nlens u$^` hzfI  
h2*&>Mc  
    '************************************************************************* u 9Tl Xn  
    'Pupil diameter `)P_X4e]`  
    '************************************************************************* ml/O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) xL"o)]a=  
*XR~fs?/*W  
    'Adjust pupil diameter (trimming volume inner hole) RlL,eU$CS  
!~kzxY  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" a-hGpYJJG  
-L3RzX  
    ' Adjust pupil location to just in front of the lens CplRnKra  
    parID = FindFullName( "Geometry.Arizona Eye" ) |ZzBCL8q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 2$UR " P  
    count = 0 _ h-X-s Y  
    While GetOperationCount(eID)>count >C66X?0cd  
        GetOperation eID, count, op (ytkq(  
        If op.Type="ShiftZ" Then .k(_ j.v  
            DeleteOperation eID,count Ku'U^=bVm:  
            count=count-1 2geC3v% 0o  
        End If qa?y lR"kA  
        count=count+1 QyQ8M1m  
    Wend oa7Hx<Y  
    op.Type = "ShiftZ" Mb!^_cS(  
    op.val1 = taq-0.01 %j; cXN  
    op.parent = parID SW, Po>Y  
    AddOperation eID, op 5Yr$dNe  
PTqS L]  
    Print "Set pupil diameter = " & pupilDiam 1i2w<VG1  
(iP,YKG1?  
    'Update AZ Eye subassembly Description n-Y'LK40Os  
    eID = FindFullName( "Geometry.Arizona Eye" ) x=)$sD-3  
    GetEntity eID, entity \]El%j4  
    entity.Description = "Accommodation = " & A & "D" RkM!BcB  
    SetEntity eID, entity bc-)y3gHU  
|SleSgS<#  
    Update n5/Q)*e0'#  
    Print "DONE!" l"8YIsir  
     P!EX;+7+x  
End Sub sxtGl^,mU:  
Tkf !Y?  
如果屈光度是4，光瞳直径是4，则会输出如下数据： U4JN,`p{  
?YO%]mTP  
Accommodation = 4 Diopters }XU- J An  
Pupil Diameter = 4 mm PMcyQ2R->  
Set aqueous humor thickness = 2.81 5c8x: e@  
Set anterior lens radius = 10.4 and conic constant = -2.375869 l<?wB|1'  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 tAUMSr|?  
Set lens thickness = 3.927 KMcP!N.I  
Set lens index of refraction = 1.42672 8b!_b2Za  
Set pupil diameter = 4 W{d/m;<@N  
DONE! ;*p} ~#2  
u!W00;`L  
（文章来源：讯技光电）
查看本帖完整版本: [-- FRED运用：Arizona眼睛模型 --] [-- top --]

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