[技术]Arizona眼睛模型 [复制链接]

简介 4a 5n*6G!  
3}+/\:q*  
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。 a} /Vu"  
Dxe|4"%^  
模型 9@j~1G%^  
M&K@><6k,k  
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。 \xdt|:8  
:X!(^a;]  
WLpn,8qsY  
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. dnx}c4P  
V?"^Ff3m!  
光源 vW_A.iI"e  
^Y&Cm.w  
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。 0L1P'*LRU  
Y}Dp{  
GWhZ Mj  
pFK |4
u  
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。 kgIWgk%  
:b>|U
"ux  
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。 !69^kIi$  
`~RV  
QA3l:D}u  
<Hp"ZCN  
视网膜的散射 ^"
Y'zIL  
6?lg 6a/eO  
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。 M;9+L&p=  
NWg\{a  
7L]?)2=  
^M9oTNk2  
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。 ~ /[Cgh0  
mx[^LaR>v  
So^`L s;
S  
e.+)0)A-  
脚本 @
Otc$hj  
+,[3a%c)H  
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： q+z\Y?  
]~zJ
7I  
g?VME]:  
hq*JQb;Y}  
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。 gh}AD1TN]  
余下的脚本计算与屈光度有关的所有参数。 u s0'7|{q  
5:d2q<x:{  
分析 acZHb[w  
a7|&Tbv  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 9vTQ^*bm  
!VHIl&Mos  
ZX;k*OrW  
脚本代码 55
DzBV
  
aX%Zuyny  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. nnNg^<[k3  
w'0M>2  
Dim entity As T_ENTITY UT~2}B9fc  
Dim op As T_OPERATION ;5k|gW  
Dim mat As T_MODELMATERIAL (3h*sd5ly  
Dim A As Double ?GarD3#A  
Dim pupilDiam As Double gk1S"H  
Dim eID As Long `Cf en8  
Dim parID As Long 5)
7mjyo%  
Dim count As Integer =)YYx8
gR  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double N)*e^Nfb  
Dim tlens As Double, nlens As Double mv.I.EL  
Dim curv As Double, conic As Double I0vnd7  
Dim ok As Long X@&uu0JJ  
3x0wk9lND  
Sub Main FBAC9}V"  
&] 6T^.  
    '用户输入对话框 O`j
A-t  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 T:">,*|  
        TextBox 220,21,40,21,.TextBox1 'default: 0 UMwMXmZNJ  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *UoHzaIqz  
        OKButton 40,91,90,21 $-?5Q~  
        CancelButton 190,91,90,21 }.) 43(>]  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 xJLO\B+gM  
        TextBox 220,49,40,21,.TextBox2 'default: 4 u^$Md WP  
    End Dialog .GN$H>
')  
    Dim dlg As UserDialog 9:i,WJO  
0r ; nz]'  
    ok = Dialog (dlg) B9Q.s  
&jZ|@K?  
    If ok=0 Then    'cancel button was pressed k3[h'.ps  
        Print "Execution cancelled." ]3,.g)U*m  
        End 9*+0j2uhQ  
    End If fsc~$^.~\  
B;]5,`#!
 
    'Assign accommodation and pupil diameter & use defaults if field left empty rY?F6'}  
    If dlg.TextBox1 = "" Then NND=Zxl  
        A = 0           'Default accommodation CPNN!%-  
    Else :@`(}5F4  
        A = CDbl(dlg.TextBox1) >X,A
g  
    End If KbdfSF$  
nl9Cdi]o  
    If dlg.TextBox2 = "" Then -f2`qltjb  
        pupilDiam = 4   'Default pupil diameter *tM7>  
    Else I/V)z9  
        pupilDiam = CDbl(dlg.TextBox2) XH:gQ9FD  
    End If _#D\*0J  
>_aio4j}r  
    Print " " ,V]A63J  
    Print "Accommodation = " & A & " Diopters" 7;}3{z  
    Print "Pupil Diameter = " & pupilDiam & " mm" px}7If  
T[XP\!z]B!  
    ' Calculate new parameters with accommodation #f3;}1(  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness oUvk2]H  
T E&Q6  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens tkN3BQ  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |] !o*7"4  
y^QYlZO  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 4%fN\f  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ]]=-AuV.  
(OyY_`  
    tlens = 3.767 + 0.04*A                  'Lens thickness +8)]m<  
HCx%_9xlm  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {eswe  
rbK#a)7  
    'Adjust parameters to account for accommodation t&9as}  
V4eng "  
    '************************************************************************* j[/SXF\=  
    'Aqueous thickness (Position of Lens) mfngbFa1  
    '************************************************************************* {Bq"$M!Y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) F!)M<8jL&9  
    GetCustomElement eID, entity wyrI8UY  
xZP
>g  
    parID = FindFullName( "Geometry.Arizona Eye" ) <p^*Ydx  
YQ@dl
 
    ' Delete any shift(s) in z uZo`IKJ  
    count = 0 mS:j$$]u  
    While GetOperationCount(eID)>count c8-69hb?  
        GetOperation eID, count, op Im?= e  
        If op.Type="ShiftZ" Then "y~muE:.
 
            DeleteOperation eID,count 5X`w&(]m  
            count=count-1 ,qe]fo >  
        End If Tr+h$M1_Ja  
        count=count+1
I
mPu}  
    Wend 8|5Gv  
GX7 eRqz>  
    'Set new shift in c?.r"5#  
    op.Type = "ShiftZ" aYaG]&hb  
    op.val1 = taq P /c Q1  
    op.parent = parID \)^,PA3  
    AddOperation eID, op '&-5CpDUs  
    Print "Set aqueous humor thickness = " & taq-0.55 Mhv1K|4s  

]&C:>  
    '************************************************************************* ~U"by_  
    'Radius and conic constant of anterior lens ]27>a"p59Y  
    '************************************************************************* k5aa>6K  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ?qg^WDs$  
    GetConic eID, entity, curv, conic 8h&oSOkQk,  
3$?9uMl#  
    SetConic eID, entity, 1/Rant, CCant mUrS&&fu8  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant `1fJ:b/M  
7P/?wv9+n*  
    '************************************************************************* 'v\1:zi  
    'Radius and conic constant of posterior lens I&TTr7  
    '************************************************************************* ,DQGv_  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) V[o7Jr~  
    GetConic eID, entity, curv, conic DKy>]Hca  
:DtZ8$I`]C  
    SetConic eID, entity, 1/Rpost, CCpost Io$w|~x  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost V!T^w
h;  
E-UB -"6  
    '************************************************************************* _M8G3QOx  
    'Lens thickness (Position of posterior lens surface) T}n N=Q4  
    '************************************************************************* (KT38RhA  
K1?Z5X(b  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) >Z#uFt0<Pm  
k$e D(cW$  
    ' Delete any z-shift(s) 9W{,=.%MX$  
    count = 0 %f3c7\=C  
    While GetOperationCount(eID)>count w^06z,  
        GetOperation eID, count, op :/o C:z\h  
        If op.Type="ShiftZ" Then L;/9L[s,  
            DeleteOperation eID,count J[
e}  
            count=count-1 xS=_yO9-  
        End If O&`U5w  
        count=count+1 k2EHco0BG  
    Wend
,>D ja59  
/xl4ohL$a  
    'Set new z-shift Err4 %-  
    op.Type = "ShiftZ" 9@:BK;Fi  
    op.val1 = tlens }1QI"M*  
    op.parent = parID z-n>9  
    AddOperation eID, op Z5((1J9  
    Print "Set lens thickness = " & tlens rHvF%o  
M{C6rm|  
    '************************************************************************* qBT_! )h   
    'Lens index of refraction an3~'g?  
    '************************************************************************* fv|]=
e  
    eID = FindMaterial( "Lens" ) T"n{WmVQ  
    GetModelMaterial eID, mat nN>J*02(  
1TKEm9j]u  
    mat.Nd = nlens ^'m\D;
 
    SetModelMaterial eID, mat U z"sdi  
    Print "Set lens index of refraction = " & nlens d; 9*l!CF  
qs=Gj?GwGQ  
    '************************************************************************* + c`AE  
    'Pupil diameter z)}3**3'y  
    '************************************************************************* ,mBZ`X@N  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) {}V$`L8  
4w'lu"U  
    'Adjust pupil diameter (trimming volume inner hole) F"!agc2!  
YP
u9Q  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ful#Px6m  
2b5#PcKa  
    ' Adjust pupil location to just in front of the lens +}P%HH]E/p  
    parID = FindFullName( "Geometry.Arizona Eye" ) J0=7'@(p  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) q(,cY
u  
    count = 0 djWcbC=g_  
    While GetOperationCount(eID)>count 1j11|~  
        GetOperation eID, count, op ^V[/(Lq  
        If op.Type="ShiftZ" Then .Y;b)]@f  
            DeleteOperation eID,count 1@xP(XS  
            count=count-1 |+98h&U~  
        End If tv0Ha A  
        count=count+1 ny)]GvxI  
    Wend ',GV6kt_k  
    op.Type = "ShiftZ" yf!,4SUkU  
    op.val1 = taq-0.01 98GlhogWt  
    op.parent = parID u#1%P5r&X  
    AddOperation eID, op wzd`l?o,  
{;*}WPYb  
    Print "Set pupil diameter = " & pupilDiam ]fZ<`w8u}  
k0L] R5W  
    'Update AZ Eye subassembly Description r088aUO P  
    eID = FindFullName( "Geometry.Arizona Eye" ) 'TL2%T/)t  
    GetEntity eID, entity
yMb|I~k  
    entity.Description = "Accommodation = " & A & "D" ?OE#q$g  
    SetEntity eID, entity joqWh!kv7U  
K1OkZ6kl  
    Update n#4Gv|{XMD  
    Print "DONE!" b^x07lO  
     @xS]!1-  
End Sub ND5$bq Nu?  
F?9SiX[\  
如果屈光度是4，光瞳直径是4，则会输出如下数据： `?"6l5d.]  
eJHp6)2  
Accommodation = 4 Diopters ?n.)&ZIx0  
Pupil Diameter = 4 mm >.e+S?o  
Set aqueous humor thickness = 2.81 6W&_2a7*  
Set anterior lens radius = 10.4 and conic constant = -2.375869 =s;M]:  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 " !-Kd'V  
Set lens thickness = 3.927 ,X68xk.'  
Set lens index of refraction = 1.42672 OUI6 ax\[  
Set pupil diameter = 4 iCP~
O  
DONE! Ow@v"L;jF!