[技术]Arizona眼睛模型 [复制链接]

简介 sW0<f&3  
N _|tw  
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。 fvr|<3ojo  
p]x
9hZ  
模型 GI)eq:K_U8  
gJ?Vk<hp  
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。 wg=-&
-  
V]P%@<C  
CYZ0F5+t  
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. ,_I#+XiXY  
AZfW  
光源 ~c${?uf   
%Mr^~7nN  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 ehyCAp0oI  
a$]i8AeG  
L]{1@~E:q  
&'oZ]
}^0  
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。 b
>f{o_  
V2IurDE  
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。 Y *n[*N  
XG01g3  
L(DDyA{bA  
W
bGN 5?9Q  
视网膜的散射 rixt_}aE  
Q=#N4
[W'  
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。 KLCd`vr.xf  
.?)gn]#  
d#
-'DO{k  
Z&Xp9"j,@;  
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。 w=QW8q?  
Qgxpq{y  
`!@d$*:'  
Z Z9D6+R  
脚本 @w73U;9\  
vY!'@W  
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： Xsd+5="{N  
 $M|  
?C(3TKH  
D"8?4+  
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。 4}Dfi5:   
余下的脚本计算与屈光度有关的所有参数。 2JL\1=k;  
oe,yCdPs  
分析 +MyXIWmD  
6D/K=-  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ]4eIhj?  
c|<E~_.w@  
=H;F{J"  
脚本代码 #TPS?+(  
>o )v  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. D]+]Br8  
FgnPh%[u  
Dim entity As T_ENTITY xP-\)d-.aN  
Dim op As T_OPERATION Mq52B_  
Dim mat As T_MODELMATERIAL &*#Obv  
Dim A As Double +{L=cWA"  
Dim pupilDiam As Double RiiwsnjC  
Dim eID As Long 7~!F3WT{  
Dim parID As Long #D-Ttla  
Dim count As Integer pB'{_{8aA  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double |OBh:d_B]  
Dim tlens As Double, nlens As Double D.*o^{w|  
Dim curv As Double, conic As Double  >G}g=zy@  
Dim ok As Long 85qD~o?O  

L~{3W  
Sub Main 9i+.iuE%Bu  
v
\dP  
    '用户输入对话框 W9:(P  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 1<;G oC"  
        TextBox 220,21,40,21,.TextBox1 'default: 0 $
[V-M\q  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 T!Nv  
        OKButton 40,91,90,21 :%>TM/E N  
        CancelButton 190,91,90,21 (O"-6`w
[  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 d-`z1'  
        TextBox 220,49,40,21,.TextBox2 'default: 4 '+v[z=.8]  
    End Dialog B3&C
=*y  
    Dim dlg As UserDialog 7mA:~-.u  
Kp>fOe'KW  
    ok = Dialog (dlg) T\w{&3ONm  
eS/Au[wS  
    If ok=0 Then    'cancel button was pressed z!aU85y  
        Print "Execution cancelled." @t2S"s$m  
        End th%T(D5
n  
    End If 9QHV%%  
''H;/&nDX  
    'Assign accommodation and pupil diameter & use defaults if field left empty /kAbGjp0  
    If dlg.TextBox1 = "" Then x9\]C'*sO  
        A = 0           'Default accommodation =F09@C,  
    Else _b9>ZF~  
        A = CDbl(dlg.TextBox1) b<j*;n.  
    End If `]F#j ]"  
1*?L>@Wdy  
    If dlg.TextBox2 = "" Then .*
&F  
        pupilDiam = 4   'Default pupil diameter
X3m)  
    Else Y'yGhpT~  
        pupilDiam = CDbl(dlg.TextBox2) RV)
,E:?  
    End If LerRrN}~  
C(n_*8{  
    Print " " (} wMU]!_  
    Print "Accommodation = " & A & " Diopters" b\p2yJ\  
    Print "Pupil Diameter = " & pupilDiam & " mm" ~p x2kHZ  
G UK%RC8  
    ' Calculate new parameters with accommodation =>L2~>[  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness H18pVh
 
gwDVWhq  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens dg#w!etB  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 6|QIzs<Z-X  
t:YMF$Z  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens K_%gda|l+  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens oB+Ek~{z]  
\?vn0;R
4  
    tlens = 3.767 + 0.04*A                  'Lens thickness f@0Km^aUc  
QBjvbWoIG(  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction |Q$Dj!!1P  
wQYW5X  
    'Adjust parameters to account for accommodation 4wPP/`  
{ a_&L  
    '************************************************************************* ^bEC
X<,H  
    'Aqueous thickness (Position of Lens) NmTo/5s  
    '************************************************************************* ?8YbTn1f)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) L,
sFwOWY  
    GetCustomElement eID, entity [y"Yi PK  
6L3i   
    parID = FindFullName( "Geometry.Arizona Eye" ) ,zh_-2^X  
4P?@N
Jp  
    ' Delete any shift(s) in z *fI\|%K  
    count = 0 zT")!Df>'  
    While GetOperationCount(eID)>count hfpis==  
        GetOperation eID, count, op W4=A.2[q  
        If op.Type="ShiftZ" Then :XB^IyO-A  
            DeleteOperation eID,count (#nB90E{*  
            count=count-1 W!JEl|]  
        End If Lc0=5]D  
        count=count+1 vw :&c.zd  
    Wend |}Z2YDwO/  
c
G{  
    'Set new shift in ,,;vG6^a  
    op.Type = "ShiftZ" ;_m;:<  
    op.val1 = taq :A5h<=[  
    op.parent = parID *mn"GK6  
    AddOperation eID, op ;<#=|eD2  
    Print "Set aqueous humor thickness = " & taq-0.55 |OIU)53A-  
[X ]XH  
    '************************************************************************* $`<-;kI  
    'Radius and conic constant of anterior lens .\8LL,zT  
    '************************************************************************* uCc5)
  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) );{76  
    GetConic eID, entity, curv, conic czH# ~  
Px&)kEQ  
    SetConic eID, entity, 1/Rant, CCant fzUG1|$e  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant NMESGNa)z  
7,Y+FZ  
    '************************************************************************* b?:?"  
    'Radius and conic constant of posterior lens Wz;@Rl|F  
    '************************************************************************* Kf
`/ Gc!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) $Km~x  
    GetConic eID, entity, curv, conic (V0KmNCW`  
o90[,  
    SetConic eID, entity, 1/Rpost, CCpost 9&{HD  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost SDjJ?K  
*S'?u_Y7  
    '************************************************************************* y w:=$e5  
    'Lens thickness (Position of posterior lens surface) FBa-gm<9  
    '************************************************************************* zpg5
12\y  
M,we,!B0  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) rVwW%&  
Tn?D~?a
*O  
    ' Delete any z-shift(s) e^v\K[  
    count = 0 #wJ^:r-c`  
    While GetOperationCount(eID)>count 7Ac.^rv5  
        GetOperation eID, count, op r|y\FL  
        If op.Type="ShiftZ" Then 8:K_S a%  
            DeleteOperation eID,count HahA} Q  
            count=count-1 B.~[m}  
        End If Yn>FSq^Wp-  
        count=count+1 N!<X%Ym  
    Wend mteQRgC  
S";}gw?r6  
    'Set new z-shift V-18~+F~"a  
    op.Type = "ShiftZ" f6
m h_l  
    op.val1 = tlens B/B`=%~5_^  
    op.parent = parID Nhtc^DX  
    AddOperation eID, op f7Gs1{  
    Print "Set lens thickness = " & tlens  p4P"U  
.g_^! t  
    '************************************************************************* Gz2\&rmN  
    'Lens index of refraction Rp>%umDyL  
    '************************************************************************* <3x:nH @  
    eID = FindMaterial( "Lens" ) (]-RL A>  
    GetModelMaterial eID, mat ]'Gz~Z%>F  
=-avzuy#  
    mat.Nd = nlens be [E^%  
    SetModelMaterial eID, mat Fe2t[y:8h  
    Print "Set lens index of refraction = " & nlens 
'tt4"z2  
f DPLB[  
    '************************************************************************* WA5.qw  
    'Pupil diameter [_*?~  
    '************************************************************************* tUGF8?& G  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ]2_=(N\Kt  
4D6LP*  
    'Adjust pupil diameter (trimming volume inner hole) Yw\lNhoPS  
()<?^lr33  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" hLT?aQLx  
~6{U^3  
    ' Adjust pupil location to just in front of the lens c`oW-K{  
    parID = FindFullName( "Geometry.Arizona Eye" ) ]Mv
pec_B  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" )
QFFFxaeJg  
    count = 0 j%gle%_  
    While GetOperationCount(eID)>count +5GPU 9k  
        GetOperation eID, count, op b`;Cm)@X!)  
        If op.Type="ShiftZ" Then :g{ybTSEe  
            DeleteOperation eID,count biRkqc;  
            count=count-1 ?>
My&yB  
        End If wWM[Hus  
        count=count+1 8_M"lU0[  
    Wend Ged} qXn  
    op.Type = "ShiftZ" x#hSN|'"  
    op.val1 = taq-0.01 V/RV,K1/  
    op.parent = parID  p+-IvU  
    AddOperation eID, op /)sP<WPQ6  
I~nz~U:ak  
    Print "Set pupil diameter = " & pupilDiam sAnb   
t(}g;O-  
    'Update AZ Eye subassembly Description A>)Ced!  
    eID = FindFullName( "Geometry.Arizona Eye" ) z}Um$'. =  
    GetEntity eID, entity N(P2Lo{JF  
    entity.Description = "Accommodation = " & A & "D" EtQ:x$S_  
    SetEntity eID, entity 8EU/}Ym  
wM}AWmH  
    Update #VsS C1  
    Print "DONE!" VFKFO9  
     z&\N^tBv  
End Sub 7tne/Yz  
#$l:%  
如果屈光度是4，光瞳直径是4，则会输出如下数据： Hxn#vAc  
Bve',.xH  
Accommodation = 4 Diopters AuY*x;~  
Pupil Diameter = 4 mm H#G3CD2&  
Set aqueous humor thickness = 2.81 
,:0!+1  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Hk$do`H-=Y  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 <`NtTG  
Set lens thickness = 3.927 h;R>|2A  
Set lens index of refraction = 1.42672 &w:0ad|  
Set pupil diameter = 4 x:c'ek  
DONE! FytGg[#]