[技术]Arizona眼睛模型 [复制链接]

简介 ~S],)E1w  
42Gv]X  
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。 sKkk+-J4  
?G#T6$E8  
模型 L)sCc0fv7k  
\*5_gPj!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。 pV3o\bk!  
#^>5,
M2  
,pgpu !  
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. jtMN)TM  
8mCL3F  
光源 4;*o}E  

+{$NN  
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。 M=
57 d7  
J(\]39y  
Felu`@b  
kc3dWWPe  
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。 -L&FguoVB  
<V}^c/c
!  
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。 9K>
$  
5df~] -=0Y  
!;YmLJk;hN  
eQ}o;vJN  
视网膜的散射 A&
$oiLc  
f2sv$#'  
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。
JVzU'd;1!  
{jOCz1J  
/A U& X  
fNV
Nx~E  
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。 >taC_f06  
Ol,Tw=?  
X0=#e54  
>k6RmN  
脚本 (W7cQ>  
\X=?+| 9  
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： IT3xX=|b  
PD$gW`V  
6$}hb|j  
n]/7UH}(<&  
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。 o;+J3\  
余下的脚本计算与屈光度有关的所有参数。 k+au42:r  
 )"im|9  
分析 7Ca+Pe}/n,  
a'LM6A8~x  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ,FvBZ.4c3=  
YQzs0t ,  
A6APU><dm^  
脚本代码 ^K4#_H#"  
QMGMXa  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. cO,ELu  
'J&&F2O%  
Dim entity As T_ENTITY t7rz]EN  
Dim op As T_OPERATION [@U2a$k+d  
Dim mat As T_MODELMATERIAL 0ciPH:V  
Dim A As Double -q9`Btz  
Dim pupilDiam As Double \0'7p-
T6  
Dim eID As Long @$R[Js%MuO  
Dim parID As Long E\5cb[Y  
Dim count As Integer 9/rX%  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #tyHjk  
Dim tlens As Double, nlens As Double *5DOTWos  
Dim curv As Double, conic As Double $7{|  
Dim ok As Long 7l"N%e  
Cd:ofv/3  
Sub Main H7 acT  
E>j*m}b  
    '用户输入对话框 \;w+_<zE5{  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 .".xNHR#  
        TextBox 220,21,40,21,.TextBox1 'default: 0 8y!d^EQ  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *I0{1cST  
        OKButton 40,91,90,21 XG fLi  
        CancelButton 190,91,90,21 $`:/OA<.  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 mOj6 4}_`"  
        TextBox 220,49,40,21,.TextBox2 'default: 4 uf;^yQi  
    End Dialog B
_w;2ZuA  
    Dim dlg As UserDialog #un#~s 7Q  

=(kwMJ  
    ok = Dialog (dlg) A&#P=mj  
5gP#V K  
    If ok=0 Then    'cancel button was pressed 5}3Q}o#  
        Print "Execution cancelled." Z~}=q  
        End c?i=6CdD'  
    End If d[
+xLa  
-(FVTWi0
 
    'Assign accommodation and pupil diameter & use defaults if field left empty Ds|/\cI$%a  
    If dlg.TextBox1 = "" Then HFD5*Z~M  
        A = 0           'Default accommodation A~ugx~S0  
    Else _5I" %E;S  
        A = CDbl(dlg.TextBox1) JV|GEn\@N  
    End If OM!CP'u#{  
Sr)rKc  
    If dlg.TextBox2 = "" Then o/EA%q1  
        pupilDiam = 4   'Default pupil diameter ^7C?yC  
    Else cT abZc  
        pupilDiam = CDbl(dlg.TextBox2) xXl^\?HC  
    End If Ug=8:a(U.  
k~WX6rEJ  
    Print " " BJDe1W3;'  
    Print "Accommodation = " & A & " Diopters" EB'(%dH  
    Print "Pupil Diameter = " & pupilDiam & " mm" ^\kv>WBE  
W/U&w.$  
    ' Calculate new parameters with accommodation * ";A~XNx  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness f/G YDat  
*9}2Bmojv  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 7MreBs(M  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens *h Ph01  
I^'kt[P'FZ  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ]qCAog  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens :(EU\yCzK  
kQX
tO)  
    tlens = 3.767 + 0.04*A                  'Lens thickness rt] @Z`w  
7-81,ADv(  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction o >bf7+D  
b]hP;QK`U$  
    'Adjust parameters to account for accommodation %RgCU$s[>  
Ie>)U)/$  
    '************************************************************************* N<ww&GXBX  
    'Aqueous thickness (Position of Lens) w^09|k  
    '************************************************************************* 9aT#7B  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) jJ-j   
    GetCustomElement eID, entity  Z+ [Nco
 
s 
bV6}  
    parID = FindFullName( "Geometry.Arizona Eye" ) Z++JmD1J  
RWf4Wh?d  
    ' Delete any shift(s) in z n'ft@7>%h  
    count = 0 5S:#I5Wa  
    While GetOperationCount(eID)>count zRsG$)B  
        GetOperation eID, count, op ZK4/o  
        If op.Type="ShiftZ" Then Q}ho Y  
            DeleteOperation eID,count ?}y?e}y*xZ  
            count=count-1 dL5u-<y&  
        End If E7^r3#s  
        count=count+1 i
F2/:iP  
    Wend X<J NwjM%  
:i+Tf~k{  
    'Set new shift in jI0gQ [  
    op.Type = "ShiftZ" L}CjC>R!  
    op.val1 = taq 3B95t-  
    op.parent = parID X.V7od>  
    AddOperation eID, op "Q]`~u':  
    Print "Set aqueous humor thickness = " & taq-0.55 */ZrZ^?o  
n?vrsqmZ  
    '************************************************************************* |RX uO  
    'Radius and conic constant of anterior lens =p|,~q&i  
    '************************************************************************* N8;/Zd;^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) aLTC#c%U  
    GetConic eID, entity, curv, conic [9NzvC 9I  
O#fGHI<43[  
    SetConic eID, entity, 1/Rant, CCant %c)^8k;I  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ^'r/;(ZF*/  
GQO}E@W6C  
    '************************************************************************* !]7r>NS>  
    'Radius and conic constant of posterior lens DU
#6%8~  
    '************************************************************************* VqLqj$P  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) U#R=y:O?  
    GetConic eID, entity, curv, conic I:[^><?E  
K"-.K]O8E%  
    SetConic eID, entity, 1/Rpost, CCpost _c?&G`  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ]cLO-A  
u-0-~TwD  
    '************************************************************************* 4M'y9(  
    'Lens thickness (Position of posterior lens surface) p7}xgUxX  
    '************************************************************************* ?n9gqwO  
!_)*L+7f_  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Jj}+tQf  
l[mXbQd  
    ' Delete any z-shift(s) C]K|;VQ  
    count = 0 gq4le=,v  
    While GetOperationCount(eID)>count smW 7zGE  
        GetOperation eID, count, op Fu:VRul=5$  
        If op.Type="ShiftZ" Then eS9uKb5n(  
            DeleteOperation eID,count ZAVjq;bq  
            count=count-1 H->J.5~,K  
        End If Zoh[tO  
        count=count+1 GV'Y'  
    Wend v<N7o8  
XqMJe'%r  
    'Set new z-shift 
y`!~JL*  
    op.Type = "ShiftZ" VeidB!GyP  
    op.val1 = tlens -bT1Qh X  
    op.parent = parID )*ocX)AE  
    AddOperation eID, op G4][`C]8c  
    Print "Set lens thickness = " & tlens ;HRIB)wF  
'Y{fah  
    '************************************************************************* HM ;9%rtO  
    'Lens index of refraction )
.e_iE[&  
    '************************************************************************* ],9%QE  
    eID = FindMaterial( "Lens" ) \zCT""'i  
    GetModelMaterial eID, mat Lgl%fO/<t  
Bfwa1#%?  
    mat.Nd = nlens ^%tmHDNL.  
    SetModelMaterial eID, mat fOs}5J  
    Print "Set lens index of refraction = " & nlens Y S )Q#fP  
hOjy$Z  
    '************************************************************************* A46z2  
    'Pupil diameter daS l.:1  
    '************************************************************************* r=lhYn  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) v1wMXOR  
57*`y'CW  
    'Adjust pupil diameter (trimming volume inner hole) 9BgR@b  
Lq.aM.&;#  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" %7WGodlXW  
M:i;;)cq  
    ' Adjust pupil location to just in front of the lens udYk 6  
    parID = FindFullName( "Geometry.Arizona Eye" ) |9cJO@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]pC/6'  
    count = 0 X;/~d>@  
    While GetOperationCount(eID)>count 70IBE[T&  
        GetOperation eID, count, op |c,,*^  
        If op.Type="ShiftZ" Then W,'30:#Fr7  
            DeleteOperation eID,count ea!_/Y  
            count=count-1
d*;wHA,}F  
        End If YJi C}.4Q  
        count=count+1 <RQ
\nU  
    Wend _s{on/u  
    op.Type = "ShiftZ" J_) .Hd  
    op.val1 = taq-0.01 H]2cw
{2  
    op.parent = parID 5{?J5  
    AddOperation eID, op 2)oT\m  
QEo i9@3  
    Print "Set pupil diameter = " & pupilDiam U'8+YAgc  
3gN#[P  
    'Update AZ Eye subassembly Description NVqJN$z  
    eID = FindFullName( "Geometry.Arizona Eye" ) CsfGjqpf  
    GetEntity eID, entity GSck^o2{  
    entity.Description = "Accommodation = " & A & "D" fHK`u'  
    SetEntity eID, entity O~Eju  
GcXh V  
    Update S[g{ )p)  
    Print "DONE!" G 92\` Q  
     Y#[jDS(ip  
End Sub H4l*  
Fo  K!JX*  
如果屈光度是4，光瞳直径是4，则会输出如下数据： vV5dW  
A|3'9i
L{9  
Accommodation = 4 Diopters $2lrP]`>j.  
Pupil Diameter = 4 mm Q7uhz5oZ  
Set aqueous humor thickness = 2.81 c8'a<<sj  
Set anterior lens radius = 10.4 and conic constant = -2.375869 DL$O274uZ  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 9p|;Hh:  
Set lens thickness = 3.927 OEMYS I%  
Set lens index of refraction = 1.42672 EC
q(i(  
Set pupil diameter = 4 S3Q^K.e?  
DONE! z u53mZ