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 8}B*a;d  
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。 W|~Jl7hs8Q  
4[\$3t.L  
模型 ]m fI$p%  
 `zRE$O  
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。 ;Avz%2#c`  
{c 82bFiv  
Table 1. AZ眼睛模型的定义
[attachment=67931]
}JP0q  
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. m=s aUhI*9  
q5Bj0r[/o  
光源 ZQL4<fy'E  
 "ITC P<+  
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。 YN=dLr([<  
 Nu/D$m'PY  
,H_b@$]n8  
[attachment=67932]
图1. 光源和提示信息使用
p3m!Iota  
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。 Ou26QoT9XI  
%NyV 2W=~X  
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。 $0-}|u]5U  
FJ/>=2^B  
[attachment=67933]
图2. 字母F光源的设定方法光 b 8vyJb,K  
*\-R&8  
[attachment=67934]
图3. 字母F在视网膜上位置点列图
MC 8t"SB  
视网膜的散射 2s^9q9NS"  
t:NYsL  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 9/8#e+L  
 r>>4)<C7J  
"w PA;4VQ  
[attachment=67935]
图4. 视网膜朗伯散射设定
|8QXjzH  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 yN'< iTh  
 S!LLC{  
Sckt gp8  
[attachment=67936]
图5. 视网膜重点采样规格设定
8fG$><@  
脚本 BLepCF38  
)aV\=a |A  
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： 5s5GBJ?  
rE&` G[(b  
[attachment=67937]
图6. 用户对话框的创建与编辑
QU#u5sX A  
[attachment=67938]
图7. 用户对话框编辑器
b I%Sq+"}  
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。 ;s^br17z~  
余下的脚本计算与屈光度有关的所有参数。 4R c_C0O  
B% ]yLJ  
分析 [!g$|   
 8\AyKw  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 |D@/4B1P  
~PTqR2x  
[attachment=67939]
图7. 字母F在视网膜上颜色分析
1WTDF  
脚本代码 uVSc1 MS1  
slQxz;t  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. ""Ub^:ucD  
_mEW]9Sp  
Dim entity As T_ENTITY n?UFFi+a  
Dim op As T_OPERATION mY)Y47iL  
Dim mat As T_MODELMATERIAL : \{>+!`w  
Dim A As Double ZaNZUVBh  
Dim pupilDiam As Double %2S+G?$M?  
Dim eID As Long 0P+B-K>n  
Dim parID As Long T z`O+fx &  
Dim count As Integer TKwMgC}<[  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double u|.c?fW'3  
Dim tlens As Double, nlens As Double #4yh-D"  
Dim curv As Double, conic As Double x)]_]_vX  
Dim ok As Long ,k9@%{4 l  
2 cB){.E  
Sub Main A89n^@  
6Mh;ld@  
    '用户输入对话框 Juhi#&`T  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Tc3~~X   
        TextBox 220,21,40,21,.TextBox1 'default: 0 k2-:! IE  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 J2KULXF  
        OKButton 40,91,90,21 [|vE*&:uO  
        CancelButton 190,91,90,21 <[oPh(!V  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 u%s@B1j  
        TextBox 220,49,40,21,.TextBox2 'default: 4 'XbrO|%  
    End Dialog !{WIN%O  
    Dim dlg As UserDialog doX8Tq   
^zfO=XN  
    ok = Dialog (dlg) :xBG~D  
8Qo~zO  
    If ok=0 Then    'cancel button was pressed 7 6} a  
        Print "Execution cancelled." cn3F3@_"\  
        End q^I/  
    End If @)IHd6 R  
w,s++bV;L  
    'Assign accommodation and pupil diameter & use defaults if field left empty 2#XYR>[  
    If dlg.TextBox1 = "" Then `Z' h[-2`  
        A = 0           'Default accommodation 4/Mi-ls_  
    Else NDqvt$  
        A = CDbl(dlg.TextBox1) VEc^Ap1?'  
    End If MS=zG53y  
y8!#G-d5  
    If dlg.TextBox2 = "" Then O} &%R:  
        pupilDiam = 4   'Default pupil diameter ,$,c<M  
    Else 6^Q/D7U;s  
        pupilDiam = CDbl(dlg.TextBox2) FG6bKvEQm^  
    End If jG E=7  
P<OSm*;U:  
    Print " " ov9+6'zya  
    Print "Accommodation = " & A & " Diopters" h,!#YG@>  
    Print "Pupil Diameter = " & pupilDiam & " mm" ^'Z?BK  
$oo`]R_   
    ' Calculate new parameters with accommodation A><q-`bw  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness '=V!Y$tn  
4H]~]?F&  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens GdlzpBl  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens O^L#(8bC  
2BGS$$pP  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens }j_2K1NS{  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens G%q^8#  
j} .,|7X  
    tlens = 3.767 + 0.04*A                  'Lens thickness BB.^[:,dA  
l`wF;W!  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +%'!+r l  
xl]1{$1M  
    'Adjust parameters to account for accommodation Z+%w|Sx  
!%lcn O  
    '************************************************************************* )<+t#5"  
    'Aqueous thickness (Position of Lens) xis],.N  
    '************************************************************************* m8:9Uv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) T!F0_<  
    GetCustomElement eID, entity ';>A=m9(4%  
937 z*mh  
    parID = FindFullName( "Geometry.Arizona Eye" ) Ob~7r*q  
VUF$,F9  
    ' Delete any shift(s) in z >2)`/B9f4  
    count = 0 IHs^t/;Iv  
    While GetOperationCount(eID)>count ~B2,edkM  
        GetOperation eID, count, op |3:e$  
        If op.Type="ShiftZ" Then 4]P5k6 nV  
            DeleteOperation eID,count _=Eb:n+X  
            count=count-1 6 *GR_sMm  
        End If >[A7oH  
        count=count+1 #JD:i%  
    Wend GLpl  
5nA *'($j  
    'Set new shift in (=eJceE!  
    op.Type = "ShiftZ" v{44`tR   
    op.val1 = taq jY|fP!?[  
    op.parent = parID \v]esIP5R'  
    AddOperation eID, op 5IJm_oy  
    Print "Set aqueous humor thickness = " & taq-0.55 ,jc')#]9B  
\YZ7  
    '************************************************************************* 1<(('H  
    'Radius and conic constant of anterior lens # ^q87y  
    '************************************************************************* y~Ts9AE  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) /T\'&s3D+  
    GetConic eID, entity, curv, conic 921m'WE  
N\nxo0sl  
    SetConic eID, entity, 1/Rant, CCant 9:v0gE+.  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9V0@!M8S  
62D UF  
    '************************************************************************* ,VYUQE>\  
    'Radius and conic constant of posterior lens 0Uf.aP  
    '************************************************************************* hziPHuK9,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ar[I| Q_  
    GetConic eID, entity, curv, conic 7mT iO?/y<  
BufXnMh.  
    SetConic eID, entity, 1/Rpost, CCpost Iss)7I  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost >2BWie?T  
ygo4.  
    '************************************************************************* 6>)oG6  
    'Lens thickness (Position of posterior lens surface) Po*G/RKu4W  
    '************************************************************************* A1p87o>  
;QS(`SK l  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *Ud=x^JxO  
J`d_=C?J  
    ' Delete any z-shift(s) ODFCA. t  
    count = 0 sgfci{~  
    While GetOperationCount(eID)>count ?qt.+2:  
        GetOperation eID, count, op *P; cSx?2  
        If op.Type="ShiftZ" Then , #nYHD  
            DeleteOperation eID,count #e*jP&1S  
            count=count-1 3 [r9v!l  
        End If K*sav?c  
        count=count+1 /BQB7vL  
    Wend ggL^*MV  
o$rA;^2X  
    'Set new z-shift AA &>6JB{  
    op.Type = "ShiftZ" N% !TFQf  
    op.val1 = tlens !eP)"YWI3  
    op.parent = parID H-C$Jy)f"  
    AddOperation eID, op */)O8`}2  
    Print "Set lens thickness = " & tlens UpFm3gKF  
h#~\-j9>  
    '************************************************************************* 4T??8J-J  
    'Lens index of refraction ~Iz{@Ep*  
    '************************************************************************* VBq|j"o0"  
    eID = FindMaterial( "Lens" ) L )53o!  
    GetModelMaterial eID, mat EC`=nGF  
8$~^-_>n/  
    mat.Nd = nlens 8~j1  
    SetModelMaterial eID, mat M;j)F  
    Print "Set lens index of refraction = " & nlens "STd ;vR  
zXZXp~7)  
    '************************************************************************* }l<:^lX  
    'Pupil diameter 9NC?J@&B  
    '************************************************************************* r~YxtBZH+  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ep)O|_=  
&[W53Lqa  
    'Adjust pupil diameter (trimming volume inner hole) G/N1[)  
4'# ?"I  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 'B9q&k%<  
}'WEqNuE  
    ' Adjust pupil location to just in front of the lens >!3r7LgK  
    parID = FindFullName( "Geometry.Arizona Eye" ) " 7g\X$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) z]HaE|j}S  
    count = 0 pB:/oHV  
    While GetOperationCount(eID)>count <^(>o  
        GetOperation eID, count, op %?m_;iv  
        If op.Type="ShiftZ" Then :y1,OR/k  
            DeleteOperation eID,count k@|Go )~  
            count=count-1 1"S~#  
        End If FSD~Q&9&  
        count=count+1 ,lDOo+eE%:  
    Wend c|s7 cG$+-  
    op.Type = "ShiftZ" Y6RbRcJw  
    op.val1 = taq-0.01 [79iC$8B|  
    op.parent = parID :kKdda<g#  
    AddOperation eID, op o0 |T<_  
+lw8YH  
    Print "Set pupil diameter = " & pupilDiam cnz+%Y N  
2*5pjd{Kt  
    'Update AZ Eye subassembly Description `5 Iaz  
    eID = FindFullName( "Geometry.Arizona Eye" ) Q" G;L  
    GetEntity eID, entity S+bpWA  
    entity.Description = "Accommodation = " & A & "D" G]zyx"0Sqb  
    SetEntity eID, entity H (tT8Q5i  
D9JHx+Xf>  
    Update O"~CZh,:r}  
    Print "DONE!" m[qW)N:w  
     a: 2ezxP  
End Sub 88On{Kk.v  
yY_#fJj  
如果屈光度是4，光瞳直径是4，则会输出如下数据： 9@>Q7AUCQ  
,}/6Za  
Accommodation = 4 Diopters 8EY]<#PN  
Pupil Diameter = 4 mm Ya;y@44  
Set aqueous humor thickness = 2.81 7;9 Jn  
Set anterior lens radius = 10.4 and conic constant = -2.375869 LnPG+<  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ^@f.~4P*I  
Set lens thickness = 3.927 k]rc -c-  
Set lens index of refraction = 1.42672 >e!Y63`  
Set pupil diameter = 4 {ObUJ3  
DONE! F^CR$L& K  
d}<-G.&_  
（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