[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 Put+<o <  
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。 1YS{; y[o  
l9SbuT$U  
模型 M/#<=XhA  
U`:$1*(`  
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。 p~M^' k=d  
p'_*>%4~  
o,X ?  
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. /r]IY.  
^Ji5)c  
光源 v'DL >Y  
lJ}lO,g  
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。 & }}o9  
@y}1%{,%  
WF:i}+g
+^  
,!Q2^R  
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。 ^Dd$8$?[  
oU{m
\r  
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。 <S5Am%vo  
\f%jN1z  
M3x%D)*  
4egq Y0A  
视网膜的散射 Z.rKV}yjY  
-x7b6o>$  
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。 Dmn6{jyP  
qL3*H\9N  
MT|}[|_  
*R8q)Q  
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。 h*&-[nSo  
friNo^v&  
LUJKR6oT{>  
}cMb0`oA  
脚本 _kgw+NA&-H  
qifX7AXHr  
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： RXLD5$s^  
41,Mt  
P b2exS(  
HPm12&8,  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 #(
!>  
余下的脚本计算与屈光度有关的所有参数。 1_*o(HR  
,%yjEO  
分析 3fM~
R+p  
hcwKi  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 h_Q9c  
(|"KsGl  
oJ>]=^?k  
脚本代码 quVTqhg
"  
WHMt$W}%  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. KR%DpQ&{'  
0Ocy$  
Dim entity As T_ENTITY hH|3s-o  
Dim op As T_OPERATION GR Rv0M  
Dim mat As T_MODELMATERIAL -dZ7;n5&_  
Dim A As Double ]xfu@''  
Dim pupilDiam As Double @9-z8PyF  
Dim eID As Long gI<TfcC  
Dim parID As Long iLNKC'  
Dim count As Integer x{j|Tf3,G  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Kbrb;r59  
Dim tlens As Double, nlens As Double 9v8{JaI3  
Dim curv As Double, conic As Double p,Qr9p3y  
Dim ok As Long 8|OsVIe%  
oxha8CF]D  
Sub Main O4S~JE3o  
5_x8!v  
    '用户输入对话框 d.3-@^P  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 VkZrb2]v  
        TextBox 220,21,40,21,.TextBox1 'default: 0 k$j>_U? P  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 YJ3aJ^m#E  
        OKButton 40,91,90,21 @GK0j"_  
        CancelButton 190,91,90,21 pMe'fC~*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "FwbhD0Gb  
        TextBox 220,49,40,21,.TextBox2 'default: 4 R6r'[-B2  
    End Dialog p
PuE-EDk  
    Dim dlg As UserDialog y
n)K1f^  
(:4N#p  
    ok = Dialog (dlg) /Q8E12  
$0~H~-  
    If ok=0 Then    'cancel button was pressed ~DPjTR  
        Print "Execution cancelled." rzsb(  
        End 
tXV9+AJ  
    End If ?~Fk_#jz,@  
q;3.pRw(  
    'Assign accommodation and pupil diameter & use defaults if field left empty p'M5]G  
    If dlg.TextBox1 = "" Then 4p\<b8(9>  
        A = 0           'Default accommodation MkEr|w'  
    Else ) wtVFG  
        A = CDbl(dlg.TextBox1) ]d=SkOq  
    End If L}T:Y).  
1JMEniB+9  
    If dlg.TextBox2 = "" Then  \09eH[  
        pupilDiam = 4   'Default pupil diameter Ne!F p  
    Else s<Px au+A  
        pupilDiam = CDbl(dlg.TextBox2) B2w\  
    End If $T.we+u  
yV,ki^^  
    Print " " TPH`{  
    Print "Accommodation = " & A & " Diopters" ?mU 3foa  
    Print "Pupil Diameter = " & pupilDiam & " mm" O$%M.C'  
fl#gWAM  
    ' Calculate new parameters with accommodation e[.c^Hw  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness bi;?)7p&ZY  
SAMP,un7  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 'Alt+O_  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens #Mkwd5S|L  
Y_tLSOD#/  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 1D%3|_id^  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens |\;oFuCv##  

(L}  
    tlens = 3.767 + 0.04*A                  'Lens thickness PeT _Ty  
$<cio X  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ,#:*dl  
yV[9 (  
    'Adjust parameters to account for accommodation 5#3/  
G- wQ weJ9  
    '************************************************************************* sLrSi  
    'Aqueous thickness (Position of Lens) F9@,T8I  
    '************************************************************************* {\3k(NdEX  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {G$I|<MD2T  
    GetCustomElement eID, entity y=7WnQc  
&~gqEl6RF  
    parID = FindFullName( "Geometry.Arizona Eye" ) itClCEOA  
q_S`@2Dzz,  
    ' Delete any shift(s) in z QFt7L  
    count = 0 K;moV| j  
    While GetOperationCount(eID)>count mCOJ1}  
        GetOperation eID, count, op =%P'?(o|  
        If op.Type="ShiftZ" Then ]k~Vh[[  
            DeleteOperation eID,count HEdOo~/~  
            count=count-1 E`s9SE  
        End If x d
DR/KS  
        count=count+1 x}o]R  
    Wend DY1?37h  
o (fZZ`6Y  
    'Set new shift in a Mp*Ap  
    op.Type = "ShiftZ" 2r;^OWwr?  
    op.val1 = taq
%~%1Is`4J  
    op.parent = parID 3S='/^l  
    AddOperation eID, op B198_T!  
    Print "Set aqueous humor thickness = " & taq-0.55 BkfWZ O{7  
5c6CH k`:  
    '************************************************************************* $T* ##kyE9  
    'Radius and conic constant of anterior lens 9Br2}!Ny  
    '************************************************************************* dv3+x\`9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) $__e7  
    GetConic eID, entity, curv, conic ]}z;!D>  
K|*Cka{  
    SetConic eID, entity, 1/Rant, CCant Y#'mALC2  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant cy)b/4h@  
fq-$u;~h  
    '************************************************************************* G#n99X@-  
    'Radius and conic constant of posterior lens N}{CL(xi  
    '************************************************************************* [?TQ!l}8A  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) OdX-.FFl  
    GetConic eID, entity, curv, conic ,])@?TJb@  
'TclH80  
    SetConic eID, entity, 1/Rpost, CCpost bm1+|gssn  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 'G z>X :  

il^SGH  
    '************************************************************************* ),`MAevp  
    'Lens thickness (Position of posterior lens surface) 3$f%{
~3  
    '************************************************************************* .UNh\R?r  
,Ie~zZE&  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4eb<SNi  
N{n}]Js1D-  
    ' Delete any z-shift(s) a(CZGIB  
    count = 0 E\!:MCL  
    While GetOperationCount(eID)>count KLBV(`MS  
        GetOperation eID, count, op /bA\O   
        If op.Type="ShiftZ" Then Sd'Meebu  
            DeleteOperation eID,count lh
`inAt)"  
            count=count-1 kfb+OE:7  
        End If Gjuc"JR7  
        count=count+1 $hB;r  
    Wend ;aYPv8s~,:  
20g
Px;  
    'Set new z-shift 'R6D+Vk/  
    op.Type = "ShiftZ" =DT
n9}u  
    op.val1 = tlens #|*;~:fz  
    op.parent = parID HN>eS Y+  
    AddOperation eID, op =0xuH>WY}w  
    Print "Set lens thickness = " & tlens cqeId&Cg  
2^Gl;3  
    '************************************************************************* n`f},.NM|  
    'Lens index of refraction ?!(/;RU1  
    '************************************************************************* G8|[.n  
    eID = FindMaterial( "Lens" ) Lc^nNUzPo  
    GetModelMaterial eID, mat QQ@, v@j5  
s<0yQ-=.?N  
    mat.Nd = nlens jsTb0  
    SetModelMaterial eID, mat o*/\oVOq  
    Print "Set lens index of refraction = " & nlens SqY;2:  
sw*k(i  
    '************************************************************************* | (P%<  
    'Pupil diameter sBp|Lo  
    '************************************************************************* C|"T!1MlY4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) XboOvdt^|  
GN{\ccej  
    'Adjust pupil diameter (trimming volume inner hole) i2b\` 805  
Cq1t[a  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" T,(IdVlJ  
Kbx(^f12  
    ' Adjust pupil location to just in front of the lens Wf_aEW&n  
    parID = FindFullName( "Geometry.Arizona Eye" ) dv4)fG]W;_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) IC[SJVH;  
    count = 0 P>euUVMPz4  
    While GetOperationCount(eID)>count do*`-SDy  
        GetOperation eID, count, op aGp <%d  
        If op.Type="ShiftZ" Then 8s8q`_.)(  
            DeleteOperation eID,count 3f's>+,#%  
            count=count-1 F~a5yW:R=)  
        End If b7v] g]*  
        count=count+1 0
5*_h0}  
    Wend A4';((OXy  
    op.Type = "ShiftZ" u!g=>zEu  
    op.val1 = taq-0.01 8q7KqYu  
    op.parent = parID cv:nlq)  
    AddOperation eID, op }3:TPW5S  
eJ{"\c(  
    Print "Set pupil diameter = " & pupilDiam SfJ/(q  
lGG
1d  
    'Update AZ Eye subassembly Description H#
U{i  
    eID = FindFullName( "Geometry.Arizona Eye" ) "+nURdicO  
    GetEntity eID, entity toTAWT
D  
    entity.Description = "Accommodation = " & A & "D" voQ,K9  
    SetEntity eID, entity *-+~H1tP  
!::k\}DS  
    Update {KwLcSn  
    Print "DONE!" nS?HH6H  
     3}g?d/^E3  
End Sub ?0[%+AD hM  
b,T=0W  
如果屈光度是4，光瞳直径是4，则会输出如下数据： >jl"Yr#  
N_pJE?  
Accommodation = 4 Diopters [%l+ C~m  
Pupil Diameter = 4 mm Q
k-y0  
Set aqueous humor thickness = 2.81 |&n dQ(!l  
Set anterior lens radius = 10.4 and conic constant = -2.375869 e@]cI/j  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 vW$]:).  
Set lens thickness = 3.927 R~RY:[5?w  
Set lens index of refraction = 1.42672 Rz=]K
eZu  
Set pupil diameter = 4 tY# F8a&  
DONE! m$LZ3=v%8  
D4#,9?us