[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 N(W;(7  
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。 Bp`?inKBOd  
m]$!wp  
模型 ~g+?]Lk}  
N4Z%8:"pj  
模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 UHYnl]  
Wej8YF@  
w
TGH5}QZ+  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. &oTUj'$  
%W=S*"e-  
光源 !52]'yub  
;5A  
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。 gh3XC.&  
{
mK=Vig  
lz1l1.f8  
SXn1v.6  
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。  `k/hC  
O<Rm9tZ8  
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。 LoQ
m&3/  
R g7 O  

SNB>  
,mR$YT8  
视网膜的散射 'Jww}^h1  

QXnL(z  
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。 V^W
R(Q}  
B(x i  
r<38; a  
X|)Ox ,(  
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。 _4VF>#b  
y|1,h}H^n  
5 iUT#  
L\--h`~YU  
脚本 w:P$S  
}UK<tUO  
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： ,lLkAd?q  
U)%gzXTZ%  
#y }{ 'rF?  
Z> jk\[  
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。 ,rT62w*e  
余下的脚本计算与屈光度有关的所有参数。 M/XxiF  
vq|o}6Et  
分析 lL.3$Rp;  
3>Ts7 wM  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 B>}=x4-8  
;ZMm6o  
#E%0 o  
脚本代码 A`x_M!m  
fX=o,=-f  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. Sdl1k+u  
Zb<IZ)i#1  
Dim entity As T_ENTITY C=&7V  
Dim op As T_OPERATION j]\3>.  
Dim mat As T_MODELMATERIAL F3$@6J8<[z  
Dim A As Double ]5X=u(}  
Dim pupilDiam As Double OTs vox|(  
Dim eID As Long #%t&f"j2  
Dim parID As Long dGU io?  
Dim count As Integer pJ Iq`)p5  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 7/nnl0u8  
Dim tlens As Double, nlens As Double Gj^JpG  
Dim curv As Double, conic As Double J0@<6~V6o  
Dim ok As Long D7.|UG?G  
9Ml^\|  
Sub Main ^a&-GhX;  
{//;GC*  
    '用户输入对话框 +.gM"JV  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ZSCZt&2v  
        TextBox 220,21,40,21,.TextBox1 'default: 0 R#OVJ(
#  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \~|+*^e)  
        OKButton 40,91,90,21 Gq_rZo(@  
        CancelButton 190,91,90,21 UV}\#86!  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 G9y 0;br  
        TextBox 220,49,40,21,.TextBox2 'default: 4 d7 )&Z:  
    End Dialog %$K2$dq5  
    Dim dlg As UserDialog 'r;C(Gh6  
%c[Q_  
    ok = Dialog (dlg) +L(0R&C  
5g9lO]WDI  
    If ok=0 Then    'cancel button was pressed @Sb 86Ee  
        Print "Execution cancelled." 9aYDi)  
        End tHlKo0S$0  
    End If bvY'=   
sHC4iMIw  
    'Assign accommodation and pupil diameter & use defaults if field left empty \*{tAF  
    If dlg.TextBox1 = "" Then 6E~T$^Q}  
        A = 0           'Default accommodation ;Ml??B]C  
    Else ,MkldCV  
        A = CDbl(dlg.TextBox1) ATq)8Rm\  
    End If >iefEv\  
.kO!8Q-;%  
    If dlg.TextBox2 = "" Then kkfwICBI  
        pupilDiam = 4   'Default pupil diameter Z|&Y1k-h  
    Else /">A3bq  
        pupilDiam = CDbl(dlg.TextBox2) )Ih'0>=  
    End If FwU*]wx|{  
72oiO[>N'  
    Print " " L`E^BuP/  
    Print "Accommodation = " & A & " Diopters" ,0ZkE}<=w  
    Print "Pupil Diameter = " & pupilDiam & " mm" HF@K$RPK  
C1 qyjlR  
    ' Calculate new parameters with accommodation x!$Dje}  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness @.T w*t  
JN;92|x  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens DoV<p?U  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens
7gIK+1
`  
9y/gW
E  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens P$4h_dw  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens pyPS5vWG  
qkX}pQkG)h  
    tlens = 3.767 + 0.04*A                  'Lens thickness OE,uw2uaT  
V&)lS Qw  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction XAN{uD^3\%  
F$a?} }  
    'Adjust parameters to account for accommodation .;6G?8`  
nsChNwPX  
    '************************************************************************* YXC?q  
    'Aqueous thickness (Position of Lens) ni @Mqb  
    '************************************************************************* Zkn$D:
 
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) G/tah@N[7  
    GetCustomElement eID, entity 4{2)ZI#  
b}P5*}$:9"  
    parID = FindFullName( "Geometry.Arizona Eye" ) <.c@l,[.z  
9:tvkl  
    ' Delete any shift(s) in z
1iOQ
8hD  
    count = 0 6 isz  
    While GetOperationCount(eID)>count =}@
m$g  
        GetOperation eID, count, op N_jCx*.G  
        If op.Type="ShiftZ" Then }@Mx@ S  
            DeleteOperation eID,count ~'/I[y4t  
            count=count-1 ;1Kxqpz_i  
        End If i*16kdI.  
        count=count+1 5gpqN)|)[  
    Wend F">>,Oc)U"  
.HTX7mA3  
    'Set new shift in t(SSrM]  
    op.Type = "ShiftZ" #A|~s;s>N  
    op.val1 = taq ~<0!sE&y  
    op.parent = parID 7h?yAgDv~  
    AddOperation eID, op I+ipTeB^  
    Print "Set aqueous humor thickness = " & taq-0.55 ,6[}qw)*  
QC:/xP  
    '************************************************************************* B7Um G)C  
    'Radius and conic constant of anterior lens  )]2yTG[  
    '************************************************************************* =2%EIZ0oW  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) F\.n42Tz  
    GetConic eID, entity, curv, conic h3^
&,U  
zdA:K25"  
    SetConic eID, entity, 1/Rant, CCant 0`X%&  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Ov{f
O  
v2<roG6.V  
    '************************************************************************* l'~]8Wo1  
    'Radius and conic constant of posterior lens )Qve[O  
    '************************************************************************* 9E{Bn#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) \mZ\1wzn'{  
    GetConic eID, entity, curv, conic ?i4}[q  
hA`>SkO  
    SetConic eID, entity, 1/Rpost, CCpost ZyqTtA!A  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `~( P  
\K 01F  
    '************************************************************************* @URLFMFi  
    'Lens thickness (Position of posterior lens surface) SEY  
    '************************************************************************* ki6`d?  
C]UBu-]#S  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) NF=FbvNe  
to Ei4u)m  
    ' Delete any z-shift(s) `+b>@2D_  
    count = 0 n5_r 3{  
    While GetOperationCount(eID)>count J
H!qGV1  
        GetOperation eID, count, op o a,Ju  
        If op.Type="ShiftZ" Then R<mLG $  
            DeleteOperation eID,count ]>@; 2%YvY  
            count=count-1 {jzN  
        End If mQ#@"9l%  
        count=count+1 RIX0AE  
    Wend ~MY7Ic%  
=5&)^  
    'Set new z-shift xM%E;  
    op.Type = "ShiftZ" $4kc i@.  
    op.val1 = tlens !D%*s,t\'  
    op.parent = parID ~c!zTe  
    AddOperation eID, op ( DwIAO/S  
    Print "Set lens thickness = " & tlens Sm#;fx+  

Pi6C1uY6  
    '************************************************************************* @u/<^j3Q  
    'Lens index of refraction 32:,g4!~6  
    '************************************************************************* S6H=(l58  
    eID = FindMaterial( "Lens" ) PKC``+Ki  
    GetModelMaterial eID, mat ?{qw /&  
k=Ef)'  
    mat.Nd = nlens  49 3ik  
    SetModelMaterial eID, mat tZ[BfO  
    Print "Set lens index of refraction = " & nlens ~0?p @8  
&RXd1>|c2  
    '************************************************************************* ZP?k|sEH  
    'Pupil diameter 6f=/vRAh$  
    '************************************************************************* 8BNsh[+  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ?9X#{p>q  
xpyb&A  
    'Adjust pupil diameter (trimming volume inner hole) "<6pp4*I  
iCN@G&rVw  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" P0Na<)\'Y!  
CV4V_G  
    ' Adjust pupil location to just in front of the lens L5yxaF{]  
    parID = FindFullName( "Geometry.Arizona Eye" ) 1s\10 hK1c  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 1:7>Em<s  
    count = 0 |]A{8BBC  
    While GetOperationCount(eID)>count }p t
5.'l  
        GetOperation eID, count, op '*>LZo4  
        If op.Type="ShiftZ" Then &X+V}
 
            DeleteOperation eID,count =&"Vf!7YR7  
            count=count-1 QY+#Vp<`  
        End If kRiWNEw  
        count=count+1 V@>?lv(\  
    Wend A&9l|b-"  
    op.Type = "ShiftZ" e%bERds  
    op.val1 = taq-0.01 CX':nai  
    op.parent = parID %~p_bKd~  
    AddOperation eID, op ZX-9BJ`Q  
.ET;wK  
    Print "Set pupil diameter = " & pupilDiam eiEZtu  
pw>AQ  
    'Update AZ Eye subassembly Description H.idL6*G  
    eID = FindFullName( "Geometry.Arizona Eye" ) gn%#2:=pVu  
    GetEntity eID, entity MVt#n\_BZV  
    entity.Description = "Accommodation = " & A & "D" a #@Q.wL  
    SetEntity eID, entity 8.pz?{**T  
+8^9:w0}  
    Update Sa,N1r  
    Print "DONE!" pDkT_6Q  
     |~\K:[T&  
End Sub sF+0v p  
$+
Pv fQ  
如果屈光度是4，光瞳直径是4，则会输出如下数据： #0`"gR#+  
1.,mNY^UN  
Accommodation = 4 Diopters Ysr{1!K  
Pupil Diameter = 4 mm e_1mO 5z  
Set aqueous humor thickness = 2.81 ]3={o3[:  
Set anterior lens radius = 10.4 and conic constant = -2.375869 M8[YW|VkP  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 "[[fQpe4@  
Set lens thickness = 3.927 @0 -B&w  
Set lens index of refraction = 1.42672 C9=f=sGL  
Set pupil diameter = 4 e<9nt [  
DONE! 'R,d?ikY  
#eUfwd6.Y