[技术]Arizona眼睛模型 [复制链接]

简介 ^\Q%V
TM  
475g-t2"@  
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。 ta PqRsvu  
UN:qE oS  
模型 J8Vzf$t};  
?32i
1F!  
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。 T7O)  
G-;EB  
y=[{:
 
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. Kxz|0l  
;cp||uO  
光源 u]ps-R_$G  
.3cD.']%  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 AR&l9R[{N  
bka%W@Y%  
OK47Q{.gh  
J |U
FuD  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 *&R|0I{>  
j#Lj<jX!xR  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 DnW/q  
`~41>mM%  
1rLxF{,  
K]|hkp&  
视网膜的散射 0<fQjXn  
+kD JZ  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 kmtkh"  
JRj{Q 1J  
>$=l;jO`n  
tAujm*|&  
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。 FT J{  
vGI)c&C>  
/;E=)(w  
]v]:8>N  
脚本 ,Ik~E&Ku2'  
E0DquVrz  
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： /WK1(B:  
6VJS l%X  
uf:'"7V7  
,^eOw
WV  
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。 Hc8!cATQk  
余下的脚本计算与屈光度有关的所有参数。 $'<$:;4b3  
EV
-# E  
分析 &yOl}?u  
lk /Ke  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 , E$f"  
\pSRG=`  
2d  YU  
脚本代码 Z J1
@z.  
L&uPNcZ`-  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. U:[CcN/~3  
cjd-B:l  
Dim entity As T_ENTITY <54KWC86)J  
Dim op As T_OPERATION x;LO{S4Z  
Dim mat As T_MODELMATERIAL G{Uqp
'=G  
Dim A As Double Vh]=sd<F  
Dim pupilDiam As Double ?@MWV  
Dim eID As Long CUBL/U\=  
Dim parID As Long _x,(576~  
Dim count As Integer %kgT=<E'  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double r
@wE?hK  
Dim tlens As Double, nlens As Double CoWT  
Dim curv As Double, conic As Double :&2%x  
Dim ok As Long 0 wDhX  
iQ
LP~Z>,T  
Sub Main ;4Xx5*E  
\]\h,Y8  
    '用户输入对话框 WHfl|e  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 cHVu6I?h  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ~SsfkM"  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 6wXy;!2  
        OKButton 40,91,90,21
=GeGlI6  
        CancelButton 190,91,90,21 g9d/nRX&  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 lh!8u<yv*  
        TextBox 220,49,40,21,.TextBox2 'default: 4 O-P`HKr  
    End Dialog w6^TwjjZ$  
    Dim dlg As UserDialog V!e*J,g  
]g
,j  
    ok = Dialog (dlg) ,jD-fL/:  
Qp2~ `hD  
    If ok=0 Then    'cancel button was pressed k ,r*xt  
        Print "Execution cancelled." s5MG#M 9  
        End Xd1+?2  
    End If fWDTP|DV  
9C5F#(uY  
    'Assign accommodation and pupil diameter & use defaults if field left empty '] _7Xa'  
    If dlg.TextBox1 = "" Then U<'z,P
x6  
        A = 0           'Default accommodation NL!xkcXO  
    Else TY` R_  
        A = CDbl(dlg.TextBox1) l}#d^S/  
    End If |O"Pb`V+  
!MmbwB
'  
    If dlg.TextBox2 = "" Then fQ_tXY  
        pupilDiam = 4   'Default pupil diameter PMvm4<
  
    Else kY'C'9p  
        pupilDiam = CDbl(dlg.TextBox2) OG
q=OW  
    End If zW.Ltz  
*0r!eD   
    Print " " k9VWyq__  
    Print "Accommodation = " & A & " Diopters" 
2j1HN  
    Print "Pupil Diameter = " & pupilDiam & " mm" ww'B!Ml>F  
i=fhK~Jd  
    ' Calculate new parameters with accommodation |t#s h  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness i"E_nN"V  
sp0_f;bC  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens :cP u  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens B>cx[.#!  
@ W q8AFo  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 'l-VWqR-  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens IQmlmu  
X6?Gxf,  
    tlens = 3.767 + 0.04*A                  'Lens thickness (?.h<v1}  
yV&]i-ey  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction a<((\c_8G  
]a:T]x6'  
    'Adjust parameters to account for accommodation hWX4 P  
bPl'?3  
    '************************************************************************* Ct3+ga$  
    'Aqueous thickness (Position of Lens) 1D~B\=LL}  
    '************************************************************************* _~*ba+
{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) vQDR;T"]  
    GetCustomElement eID, entity ^6!8)7b  
=Prz|
 
    parID = FindFullName( "Geometry.Arizona Eye" ) ~4ijiw$  
LXR>M>a`  
    ' Delete any shift(s) in z (YYwn@NGj  
    count = 0 T+!0`~`  
    While GetOperationCount(eID)>count T%YN(f  
        GetOperation eID, count, op \,I{*!hw  
        If op.Type="ShiftZ" Then e.!~7c_z?  
            DeleteOperation eID,count =v{
R(IX%  
            count=count-1 X{h[   
        End If V:g
XP1P  
        count=count+1 nyG5sWMpe  
    Wend wFBSux$  
QxBH{TG  
    'Set new shift in ~AF' 6"A  
    op.Type = "ShiftZ" aZta%3`)  
    op.val1 = taq h?GE-F  
    op.parent = parID W:2]d  
    AddOperation eID, op L|A1bxt  
    Print "Set aqueous humor thickness = " & taq-0.55 G/KTF2wl7  
SMQC/t]HT  
    '************************************************************************* ^4{{ +G)j  
    'Radius and conic constant of anterior lens H\|H]:CE  
    '************************************************************************* g_"B:DR  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) G[P<!6Id!p  
    GetConic eID, entity, curv, conic op_ 1J;RF  
3tmS/tQp  
    SetConic eID, entity, 1/Rant, CCant o;pJjC]  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #}
UI  
`3dGn.M  
    '************************************************************************* os+]ct  
    'Radius and conic constant of posterior lens Mo4igP  
    '************************************************************************* *uF Iw}C/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )
c{i\F D  
    GetConic eID, entity, curv, conic 9
}d^ll&  
[?)He} _L  
    SetConic eID, entity, 1/Rpost, CCpost :IozWPs*  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost *+J`Yk7}  
Lcs?2c:%  
    '************************************************************************* {ka={7  
    'Lens thickness (Position of posterior lens surface) 3X1 U  
    '************************************************************************* ,u.A[{@py  
+a'nP=e&  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) v0%FG9Gk  
$ Vsf?ID  
    ' Delete any z-shift(s) p4Xhs@.k  
    count = 0 "s\himoa  
    While GetOperationCount(eID)>count ,Aq |IH3j  
        GetOperation eID, count, op d s}E|Q  
        If op.Type="ShiftZ" Then ESkhC
DU  
            DeleteOperation eID,count 1_)Y{3L  
            count=count-1 Dwah_ p8  
        End If !LpFK0rw  
        count=count+1 3u=>Y^wu  
    Wend u9ue>I/  
gyv@_}Y3  
    'Set new z-shift <T$rvS  
    op.Type = "ShiftZ" <\?dPRw2>  
    op.val1 = tlens ^ }|$_  
    op.parent = parID rmhL|! Y  
    AddOperation eID, op E,|OMK#   
    Print "Set lens thickness = " & tlens )oMMDHw\  
VCUsvhI  
    '************************************************************************* q>VvXUyK,  
    'Lens index of refraction >NBwtF>  
    '************************************************************************* zUJPINDb  
    eID = FindMaterial( "Lens" ) ->&amPv
 
    GetModelMaterial eID, mat C33=<r[;N<  
gCW {$d1=  
    mat.Nd = nlens EA<x$O  
    SetModelMaterial eID, mat p+:MZP -%(  
    Print "Set lens index of refraction = " & nlens 8s6^!e&  
dijHi  
    '************************************************************************* U5H5QW+  
    'Pupil diameter W%K=N-kE_  
    '************************************************************************* (.9H1aO46|  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) _z&H
O  
lD?]D&  
    'Adjust pupil diameter (trimming volume inner hole) *6]_ 6xO  
~P+;_  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 3xpygx9
 
:ZU
-Vi.b  
    ' Adjust pupil location to just in front of the lens K%NgZ(x(  
    parID = FindFullName( "Geometry.Arizona Eye" ) IlMst16q5  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) A
{\!nq_~N  
    count = 0 O29GPs  
    While GetOperationCount(eID)>count c4FU@^Vv  
        GetOperation eID, count, op Zex`n:Wl?j  
        If op.Type="ShiftZ" Then 8|IlJiJ~v  
            DeleteOperation eID,count 6Vy4]jdT5  
            count=count-1 Ly`FU)  
        End If ^ V8?6E  
        count=count+1 3aEO9v,n  
    Wend a O(&<  
    op.Type = "ShiftZ" L7$1rO<  
    op.val1 = taq-0.01 )|L#i2?:  
    op.parent = parID Yq-7!  
    AddOperation eID, op QPp>%iE@  
4Pr@<S"U  
    Print "Set pupil diameter = " & pupilDiam ddvtBAX  
J8PZVeWx  
    'Update AZ Eye subassembly Description F!ra$5u  
    eID = FindFullName( "Geometry.Arizona Eye" ) (^LR9 CW  
    GetEntity eID, entity ci{WyIh  
    entity.Description = "Accommodation = " & A & "D" Ct9*T`Gl  
    SetEntity eID, entity oJVpJA0IA  
6g%~~hX
 
    Update k3r<']S^  
    Print "DONE!" to;cF6X  
     zirnur1  
End Sub `Bv, :i  
^h"F\vIpV  
如果屈光度是4，光瞳直径是4，则会输出如下数据： K7]IAV  
n.xOu`gj  
Accommodation = 4 Diopters 7>yb8/J  
Pupil Diameter = 4 mm R ;3!?`  
Set aqueous humor thickness = 2.81 RV, cQ K  
Set anterior lens radius = 10.4 and conic constant = -2.375869 p
"=8{LrO  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &8QkGUbS<  
Set lens thickness = 3.927 >&uR=Yd  
Set lens index of refraction = 1.42672 $D(q  
Set pupil diameter = 4 %scQP{%aD  
DONE! ?E.MP7Y#V