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 {Hg.ctam  
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。 HfEU[p7)  
w'E&w)Z]  
模型 X<{kf-GP  
 Y@N-q   
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。 IGqg,OEAp  
T9N][5\  
Table 1. AZ眼睛模型的定义
[attachment=67931]
ZqH.$nXP  
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. |#G.2hMFr  
<WhdQKFf-  
光源 eK[8$1  
 5nC#<EE  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 ;zk& 7P0  
 ?Co)7}N  
IJ >qs8  
[attachment=67932]
图1. 光源和提示信息使用
M,nX@8 _h  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 Bc{j0Su  
oZm)@Vv;  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 m X2i^.zH  
/Ilve U`E  
[attachment=67933]
图2. 字母F光源的设定方法光 @$o.Z;83`r  
=Ts2a"n  
[attachment=67934]
图3. 字母F在视网膜上位置点列图
ypyqf55gK  
视网膜的散射 mcbvB5U  
.=@xTJh  
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。 5eS0 B{,c  
 {yFCGCs  
x -CTMKX  
[attachment=67935]
图4. 视网膜朗伯散射设定
;\1/4;m  
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。 /Wos{ }Z 0  
 3azyqpwU$  
C{Y0}ZrmlF  
[attachment=67936]
图5. 视网膜重点采样规格设定
DXFU~J*  
脚本 v0psth?qV  
r2dU>U*:4  
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： .T;:6/??1  
UYOveQ;  
[attachment=67937]
图6. 用户对话框的创建与编辑
rBY)rUDd4  
[attachment=67938]
图7. 用户对话框编辑器
-lICoRO#  
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。 3(?V!y{@  
余下的脚本计算与屈光度有关的所有参数。 ",&^ f  
%0-fn'  
分析 L TsX{z  
 N>a. dYXr  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 {nQ?+o3  
OGA_3|[S   
[attachment=67939]
图7. 字母F在视网膜上颜色分析
jTSN`R9@  
脚本代码 mV~aZM0'  
$qndG,([F  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. M{(g"ha  
'c]Fhe fb  
Dim entity As T_ENTITY 4\?z^^  
Dim op As T_OPERATION hD)'bd  
Dim mat As T_MODELMATERIAL p"l GR&b  
Dim A As Double ML:Zm~A1U  
Dim pupilDiam As Double N+0[p@0  
Dim eID As Long <vb%i0+b.^  
Dim parID As Long 1:Sq?=&  
Dim count As Integer r^g"%nq9/  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 3rdrNc  
Dim tlens As Double, nlens As Double \ t=ls  
Dim curv As Double, conic As Double `#g62wb,HY  
Dim ok As Long q7#4e?1  
Yee% <<S  
Sub Main +Oxw?`I$  
-e2f8PV?3  
    '用户输入对话框 ]S2F9  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 b7uxCH]Z  
        TextBox 220,21,40,21,.TextBox1 'default: 0 A r=P;6J  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 . .5s 2  
        OKButton 40,91,90,21 #B$r|rqamq  
        CancelButton 190,91,90,21 V7S[rI<<r  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 FN+x<VXo(  
        TextBox 220,49,40,21,.TextBox2 'default: 4 &eA!h  
    End Dialog )(/Bw&$  
    Dim dlg As UserDialog XJSI/jpa@  
+<})`(8  
    ok = Dialog (dlg) ._X|Ye9/  
w/49O;rV  
    If ok=0 Then    'cancel button was pressed >?L)+*^  
        Print "Execution cancelled." N9S?c  
        End t 3l-]  
    End If IE*5p6IM~  
;t xW\iy%Z  
    'Assign accommodation and pupil diameter & use defaults if field left empty 8V?*Bz-4`  
    If dlg.TextBox1 = "" Then '=V1'I*  
        A = 0           'Default accommodation AqZ()p*z  
    Else yDORL| E'  
        A = CDbl(dlg.TextBox1) hY(q@_s  
    End If dq4t@:\o0  
7`P1=`..  
    If dlg.TextBox2 = "" Then zcE` .)y  
        pupilDiam = 4   'Default pupil diameter A+QOox]<  
    Else j e;^i,&  
        pupilDiam = CDbl(dlg.TextBox2) IM(=j  
    End If 4#Rq}/h  
 qDK\MQ!  
    Print " " K&IHt?vh!  
    Print "Accommodation = " & A & " Diopters" V9\y*6#Y,  
    Print "Pupil Diameter = " & pupilDiam & " mm" Rq[VP#  
na`8ulN_  
    ' Calculate new parameters with accommodation |h 3`z  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness /ReOf<%B  
KB`">zq$u  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens b8O }XB  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens vO 3-B   
8h{;*Wr-  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;kLp}CqV  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 8eDKN9kq  
=vD}O@tN  
    tlens = 3.767 + 0.04*A                  'Lens thickness # n\|Q\W  
;/~%D(  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction @~j- -L  
'iikcf*)C  
    'Adjust parameters to account for accommodation A5 <T7~U  
JPmZ%]wA  
    '************************************************************************* qG8-UOUDt  
    'Aqueous thickness (Position of Lens) omZ bn  
    '************************************************************************* }Zp5d7(@w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Lv<)Dur0K  
    GetCustomElement eID, entity g7`uWAxZa  
*<l9d  
    parID = FindFullName( "Geometry.Arizona Eye" ) hB1Gtc4n  
J?[}h&otQ  
    ' Delete any shift(s) in z c]3^2Ag,  
    count = 0 f' &  
    While GetOperationCount(eID)>count  rT!9{uK  
        GetOperation eID, count, op +l@+e_>  
        If op.Type="ShiftZ" Then 0$I!\y\  
            DeleteOperation eID,count V?C_PMa  
            count=count-1 >vk?wY^f  
        End If I%# e\  
        count=count+1 i= s>a;*#  
    Wend 9 ?(P?H  
>YP]IQ  
    'Set new shift in od`:w[2\  
    op.Type = "ShiftZ" O/{W:hJjd  
    op.val1 = taq 2@+ MT z  
    op.parent = parID F/chE c V  
    AddOperation eID, op L}.V`v{zc  
    Print "Set aqueous humor thickness = " & taq-0.55 xOXCCf/  
F<^93a9  
    '************************************************************************* qkh.? ~  
    'Radius and conic constant of anterior lens n 7 m!   
    '************************************************************************* Dwi[aC+k  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) cwKOE?!  
    GetConic eID, entity, curv, conic zP;1mN  
Wg C*bp{  
    SetConic eID, entity, 1/Rant, CCant <B =!ZC=n  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant -Drm4sTpDb  
(??|\ &DTi  
    '************************************************************************* `Ef &h V  
    'Radius and conic constant of posterior lens Gj(UA1~1  
    '************************************************************************* D[iIj_CKQ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) js8GK  
    GetConic eID, entity, curv, conic K#],4OG  
uH?lj&  
    SetConic eID, entity, 1/Rpost, CCpost -"Q[n,"Y  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost k%v/&ojI  
!kg)84C[  
    '************************************************************************* R@H}n3,  
    'Lens thickness (Position of posterior lens surface) )gq(  
    '************************************************************************* )QiHe}  
[j`-R 0Np  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) # pz{,  
vXi}B  
    ' Delete any z-shift(s) Q|W!m0XO  
    count = 0 m%?b"kxL[  
    While GetOperationCount(eID)>count \ml6B6  
        GetOperation eID, count, op )iG+pP@.@  
        If op.Type="ShiftZ" Then G ]mX+?  
            DeleteOperation eID,count lt&30nf=  
            count=count-1 e`Z3{H}  
        End If > AV R3b  
        count=count+1 vDAv/l9  
    Wend 4$+9k;m'  
WsCzC_'j.  
    'Set new z-shift 8Bnw//_pT  
    op.Type = "ShiftZ" t(:6S$6{e  
    op.val1 = tlens >MIp r  
    op.parent = parID 8@a|~\3-  
    AddOperation eID, op WxS=Aip'  
    Print "Set lens thickness = " & tlens 9N'um%J3%s  
$PQlaivA  
    '************************************************************************* 5}4MXI4  
    'Lens index of refraction jdYv*/^  
    '************************************************************************* q61 rNOw_  
    eID = FindMaterial( "Lens" ) IK6XJsz$J  
    GetModelMaterial eID, mat #dGg !D  
r4xq%hy  
    mat.Nd = nlens AOaf,ZF 8  
    SetModelMaterial eID, mat 'c<@SVF{Zz  
    Print "Set lens index of refraction = " & nlens VM3H&$d(h  
cF[[_  
    '************************************************************************* dMwVgc:  
    'Pupil diameter V6d*O`  
    '************************************************************************* 9e Dji,  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) >gr6H1  
4[!&L:tR  
    'Adjust pupil diameter (trimming volume inner hole) /j' We-C  
8[FC  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" #1zWzt|DW  
Iq\sf-1E  
    ' Adjust pupil location to just in front of the lens t@/r1u|iq  
    parID = FindFullName( "Geometry.Arizona Eye" ) ^tuJM:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) cQv*lvG9>  
    count = 0 =fHt|}.K  
    While GetOperationCount(eID)>count $XI5fa4Tt  
        GetOperation eID, count, op  j>s%q .  
        If op.Type="ShiftZ" Then P N_QK Z  
            DeleteOperation eID,count w'5~GhnP+  
            count=count-1 zF]hf P0Q  
        End If zoOm[X=?3  
        count=count+1 vfegIoZ  
    Wend ;8g#"p*&  
    op.Type = "ShiftZ" 0{PK]qp7  
    op.val1 = taq-0.01 EW4XFP4 c  
    op.parent = parID -JZl?hY(  
    AddOperation eID, op !*|CIxk(  
KX<RD|=  
    Print "Set pupil diameter = " & pupilDiam %4L|#^7:  
W{;!JI7;z  
    'Update AZ Eye subassembly Description f8?K_K;\   
    eID = FindFullName( "Geometry.Arizona Eye" ) N"t, 6tH  
    GetEntity eID, entity =10t3nA1$  
    entity.Description = "Accommodation = " & A & "D" BJj~fNm1Zr  
    SetEntity eID, entity /,0t,"&Aqa  
\hM6 ykY-  
    Update MO#%w  
    Print "DONE!" r 'jVF'w  
     rP`\<}a.  
End Sub z7PPwTBa  
$z mES tcm  
如果屈光度是4，光瞳直径是4，则会输出如下数据： Ky nZzR  
Y\p yl  
Accommodation = 4 Diopters ydns_Z  
Pupil Diameter = 4 mm }UGPEf\  
Set aqueous humor thickness = 2.81 *=/XlSWF  
Set anterior lens radius = 10.4 and conic constant = -2.375869 nLtP^ 1~9H  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ;*Z w}51  
Set lens thickness = 3.927 syZ-xE]}  
Set lens index of refraction = 1.42672 =_yOX=g|  
Set pupil diameter = 4 \R-u+ci$ZY  
DONE! x(b&r g.-0  
+&?VA!}.  
（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