[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ZN ?P4#ZS  
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。 'c<@SVF{Zz  
g/q$;cB  
模型 0OMyE9jJJ  
NW9k.D%  
模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 1*x4T%RF$  
CW=-@W7  
Xklp6{VH9  
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. 4[!&L:tR  
/j'We-C  
光源 [<sBnHbvQ.  
Ac.z6]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。 9&W\BQ  
5Wi5`8m  
R^F99L  
`4&\ %9  
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。 {-S0m=  
A?;/]m;  
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。 ,7M9f  
&K^h'>t'  
@/JGC%!  
?XGZp?6  
视网膜的散射 2+GF:[$  
){>;eky  
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。 `>8|  
?k_=?m  
-lMC{~h\(S  
[-$&pB>w8'  
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。 l:HO|Mq  
X2i<2N*@  

u3,b,p  
oqDW}>.  
脚本 FZA8@J|Q4  
/p>"|z  
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： ]jHB'Y  
8`VMdo9  
3<+l.Wly  
v&XG4 &  
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。 !gf&l ^)  
余下的脚本计算与屈光度有关的所有参数。 l.BSZhO$  
&9s6p6eb  
分析 hkU# lt  
il-&d]AP  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Vn/6D[}Tu  
XY4s  
RV(}\JU  
脚本代码 *=/XlSWF  
u khI#:[  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^1cqx]>E  
)edM@beY_  
Dim entity As T_ENTITY e('c9 Y  
Dim op As T_OPERATION aYj3a;EmU  
Dim mat As T_MODELMATERIAL NM8F  
Dim A As Double $e*Nr=/  
Dim pupilDiam As Double Pm?6]] 7  
Dim eID As Long ,Fr{i1Ky  
Dim parID As Long ~!A,I 9  
Dim count As Integer Pucf0 #  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 9i`LOl:;  
Dim tlens As Double, nlens As Double `P z !
H  
Dim curv As Double, conic As Double IWT##']G  
Dim ok As Long r>)\"U#  
x9_ Lt4  
Sub Main v}_$9&|S  
Q49|,ou[H  
    '用户输入对话框 "Z{^i3gN  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 {9l4 pT3  
        TextBox 220,21,40,21,.TextBox1 'default: 0 84knoC  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 bm+ Mr  
        OKButton 40,91,90,21 v%FV
z  
        CancelButton 190,91,90,21 @P.l8|w  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 2h
px%H  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ^2??]R&Q  
    End Dialog W"Rii]GK"  
    Dim dlg As UserDialog U50X`J  
rzTyHK[  
    ok = Dialog (dlg) }%1E9u  
ZbGyl}8ua  
    If ok=0 Then    'cancel button was pressed vv8$u3H  
        Print "Execution cancelled." Z0'3.D,l  
        End Yj"UD:p  
    End If { &qBr&kg  
v[|iuOU  
    'Assign accommodation and pupil diameter & use defaults if field left empty cu"%>>,,  
    If dlg.TextBox1 = "" Then eP2 yU  
        A = 0           'Default accommodation vB Jva8;Q  
    Else *m"mt  
        A = CDbl(dlg.TextBox1) A|&EI-In  
    End If T#BOrT>V  
1Jd:%+T  
    If dlg.TextBox2 = "" Then 1=D!C lcb  
        pupilDiam = 4   'Default pupil diameter :qZ^<3+:  
    Else )b7mzDp(  
        pupilDiam = CDbl(dlg.TextBox2) =['ijD4TW  
    End If cnc$^[c  

z]WT>4  
    Print " " ec0v
g.>p  
    Print "Accommodation = " & A & " Diopters" _YJwF1e+M  
    Print "Pupil Diameter = " & pupilDiam & " mm" -?(RoWv@X&  
Ya. $x~  
    ' Calculate new parameters with accommodation Lf-8G5G  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Qd./G5CC  
bk?\=4B:E  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens b?^n'0
 
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens +?<jSmGW  
QCo^#-   
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens l>iU Q&V  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens r%#qbsN  
F,zJdJ  
    tlens = 3.767 + 0.04*A                  'Lens thickness /7#
&q
x8  
Yru[{h8hw`  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction xH0/R LK3J  
4{?x(~  
    'Adjust parameters to account for accommodation %;5hHRA  
[Ok8l='  
    '************************************************************************* $>
UzXhf}\  
    'Aqueous thickness (Position of Lens) hJ<2bgQo  
    '************************************************************************* dF,FH-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) r&[~/m8zl  
    GetCustomElement eID, entity ~<%cc+;`  
UE4#j\  
    parID = FindFullName( "Geometry.Arizona Eye" ) W% [
5~N  
,54<U~Lg:  
    ' Delete any shift(s) in z x\DkS,O  
    count = 0 wl%1B64  
    While GetOperationCount(eID)>count hF~B&^dd.  
        GetOperation eID, count, op f3>/6C  
        If op.Type="ShiftZ" Then _:L*{=N  
            DeleteOperation eID,count H1[aNwLr  
            count=count-1 ~roHnJ>  
        End If R}>Do=hAO  
        count=count+1 `O{Uz?#*x  
    Wend l)8V:MK  
>DRs(~|V#  
    'Set new shift in +7^Ul6BB#K  
    op.Type = "ShiftZ" ^ztf:'l@C  
    op.val1 = taq O5Lv:qAa  
    op.parent = parID 0Nu]N)H5<l  
    AddOperation eID, op *ls6#j@  
    Print "Set aqueous humor thickness = " & taq-0.55 a{+oN $  
}'W^Ki$  
    '************************************************************************* }WbN)  
    'Radius and conic constant of anterior lens l.x }I"tf  
    '************************************************************************* FQFENq''B  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 8j}
m\^si  
    GetConic eID, entity, curv, conic 6dL>Rzl$Dk  
\bOjb\ w$  
    SetConic eID, entity, 1/Rant, CCant r!^\Q7  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant b-?o?}*  
w8 $Qh%J'<  
    '************************************************************************* %SGO"*_  
    'Radius and conic constant of posterior lens <.b$ gX  
    '************************************************************************* ^wa9zs2s;/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) [,^dM:E/  
    GetConic eID, entity, curv, conic Lf
#G?]@  
Y14R"*t~  
    SetConic eID, entity, 1/Rpost, CCpost 1Q SIZoK7  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost >@U<?
wP  
Rda1X~-g  
    '************************************************************************* p2vBj.*J  
    'Lens thickness (Position of posterior lens surface) Nr9[Vz?$P  
    '************************************************************************* /8}+#h)[  
S I7B6c  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) \`&pk-uW  
Y:%)cUxA  
    ' Delete any z-shift(s) +^?
-}v  
    count = 0 N[bN"'U/1  
    While GetOperationCount(eID)>count dyzwJ70K  
        GetOperation eID, count, op OLNn3 J  
        If op.Type="ShiftZ" Then /K) b0QX  
            DeleteOperation eID,count <IyL
LQ+v  
            count=count-1 ^-GX&O
Da  
        End If Qz+d[%Q}x  
        count=count+1 @>2rz  
    Wend xm|4\H&Bg  
m5w9l"U]H  
    'Set new z-shift )8 :RiG2B  
    op.Type = "ShiftZ" ~'J 
=!Xy  
    op.val1 = tlens I`W-RWZ  
    op.parent = parID :ECK $Cu  
    AddOperation eID, op Y-q@~vZ]  
    Print "Set lens thickness = " & tlens BhW]Oq&  
x}<G
!*3  
    '************************************************************************* &8+6!T
N7  
    'Lens index of refraction ,{?bM  
    '************************************************************************* d Zz^9:C+  
    eID = FindMaterial( "Lens" ) CY3\:D0I  
    GetModelMaterial eID, mat &n]Z1e}5  
:Q ?J}N  
    mat.Nd = nlens OF<n T  
    SetModelMaterial eID, mat o|qeh<2=x  
    Print "Set lens index of refraction = " & nlens 'Z2N{65  
QP5:M!O<)  
    '************************************************************************* EO/cW<uV'  
    'Pupil diameter "1!.^<V*  
    '************************************************************************* V,XP&,no\j  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 8U2wH  
B:- KZuO  
    'Adjust pupil diameter (trimming volume inner hole) ~|Ih JzDt  
EB2^]?  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ;}eEG{`Y  
7tl)4A6  
    ' Adjust pupil location to just in front of the lens K;y\[2;}e,  
    parID = FindFullName( "Geometry.Arizona Eye" ) !|<f%UO  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Wqs.oh  
    count = 0 :qCm71*  
    While GetOperationCount(eID)>count I0l.KiBm  
        GetOperation eID, count, op DAMpR3  
        If op.Type="ShiftZ" Then _UBJPb@=U  
            DeleteOperation eID,count /cL9?k;o  
            count=count-1 [wy3Ld  
        End If ;h-G3>Il  
        count=count+1 /[|}rqX(  
    Wend U.pr} hq  
    op.Type = "ShiftZ" e(n2+S#N  
    op.val1 = taq-0.01 TFJ{fLG  
    op.parent = parID Sa[EnC  
    AddOperation eID, op j |'#5H`  
v[,v{5b  
    Print "Set pupil diameter = " & pupilDiam P96Cw~<Q?  
7:VEM;[d  
    'Update AZ Eye subassembly Description S0.- >"L  
    eID = FindFullName( "Geometry.Arizona Eye" ) U/3e,`c  
    GetEntity eID, entity k\Z;Cmh>  
    entity.Description = "Accommodation = " & A & "D" cu479VzPx:  
    SetEntity eID, entity 0K$WSGB?6j  
^;)SFmjg%  
    Update (Y'UvZlM%P  
    Print "DONE!" q-3J.VLJ5H  
     SA`J.4yn  
End Sub Pa+AF  
v E3{H  
如果屈光度是4，光瞳直径是4，则会输出如下数据： c+E//X|  
DV7<n&P  
Accommodation = 4 Diopters k5fH;  
Pupil Diameter = 4 mm rY[3_NG%  
Set aqueous humor thickness = 2.81 sxN>+v11z  
Set anterior lens radius = 10.4 and conic constant = -2.375869 m0BG9~p|  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 a8bX"#OR&N  
Set lens thickness = 3.927  +eDN,iv  
Set lens index of refraction = 1.42672 ^B<PD]  
Set pupil diameter = 4 {hs2?#p  
DONE! ubzb  
kH>vD =q>