[技术]Arizona眼睛模型 [复制链接]

简介 |+q_kx@?l  
|CDM(g
>%  
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。 D<6$@ZJ  
X$>F78e*  
模型 T;92M}\  
v:P]o9Oj8  
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。 l&ueD&*4&  
KMj\A d  
t2o{=!$WH  
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. x#EE_i/W  
$&as5z8  
光源 |reA`&<q  
; BN81;  
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。 o99ExQ.  
R'k`0  
vTK%4=|1}!  
<-v zS;  
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。 =HCEUB9Fs  
&u2;S?7m  
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。 2R&\qZ<  
!i;6!w  
SUc%dpXZa  
0V
1GX~2  
视网膜的散射 @:}c(j  
Hh1_z
d|  
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。 [Arf!W-QG  
='h2z"}\Bn  
@wR3L:@  
Y)1/fEM  
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。 \ASt&'E  
GOc   
;;,7Jon2  
/TpTR-\I0  
脚本 $X#y9<bW  
;7P'>j1?U  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： spV7\Gs.@  
j L|6i-?!  
l(Rn=
?  
9lb?%UFe  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 /3ohm|!rW  
余下的脚本计算与屈光度有关的所有参数。 G,)zn9X  
#d@wjQ0DW  
分析 Ol>q(-ea  
3(WijtH  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ?@rd,:'dE  
<+k&8^:bi  
i1B!oZ3q  
脚本代码 f7x2"&?vg  
7_I83$
p'  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. Ek L2nI  
%+~\I\)1  
Dim entity As T_ENTITY ]=~dyi  
Dim op As T_OPERATION 4C*ywP  
Dim mat As T_MODELMATERIAL [J,
.?'V  
Dim A As Double zS%XmS\  
Dim pupilDiam As Double OD8 fn  
Dim eID As Long [~9UsHfH  
Dim parID As Long h!w::cV  
Dim count As Integer UMGiJO\yH  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double VhO%4[Jl  
Dim tlens As Double, nlens As Double g+#awi7  
Dim curv As Double, conic As Double MKBDWLCB  
Dim ok As Long &&
&-P\3  
+u$l]~St\  
Sub Main I){4MoH.  
4'O,xC  
    '用户输入对话框 b}
K,wAx  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 *5fe
B#  
        TextBox 220,21,40,21,.TextBox1 'default: 0 HA,o2jZ?In  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 q}LDFsU  
        OKButton 40,91,90,21 .ck?JXg  
        CancelButton 190,91,90,21 gQeQy  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?Lg(,-:  
        TextBox 220,49,40,21,.TextBox2 'default: 4 *~^63Nx!  
    End Dialog c~R'`Q  
    Dim dlg As UserDialog [M\ an6h6O  
RIMSXue*Ha  
    ok = Dialog (dlg) ,\M77V  
PJ5}c!o[  
    If ok=0 Then    'cancel button was pressed  (Q8!5s  
        Print "Execution cancelled." ;%e)t[5  
        End ?AyxRbk  
    End If ~IhM(Q*mO!  
tj13!Cc}e`  
    'Assign accommodation and pupil diameter & use defaults if field left empty Xz^nm\  
    If dlg.TextBox1 = "" Then MfL7|b)  
        A = 0           'Default accommodation J0!V(  
    Else RcYUO*  
        A = CDbl(dlg.TextBox1) ]rv\sD`[  
    End If e0`z~z]6&  
cB uuq  
    If dlg.TextBox2 = "" Then ^-"I
wy  
        pupilDiam = 4   'Default pupil diameter b? ); D  
    Else \bARp z?a  
        pupilDiam = CDbl(dlg.TextBox2) A6]:BuP;c  
    End If &ksuk9M  
>PA*L(Dh%  
    Print " " ,U\s89  
    Print "Accommodation = " & A & " Diopters" zH]oAu=H  
    Print "Pupil Diameter = " & pupilDiam & " mm" Tx.N#,T|  
;I4vPh5Q  
    ' Calculate new parameters with accommodation So1
TH%  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness *)E${\1'<  
kSz+UMC-7:  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [.}qi[=n  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens d0>U-.  
~[Tcl  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens =ANr|d  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens z x-[@G  
<U3X4)r  
    tlens = 3.767 + 0.04*A                  'Lens thickness =Kkqk  
'FXM7D   
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction w % Hj'  
V}s/knd
 
    'Adjust parameters to account for accommodation "u6pl);G  
H,%bKl#  
    '************************************************************************* (%B{=w}8  
    'Aqueous thickness (Position of Lens) _pTcSp3  
    '************************************************************************* :Qge1/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) )gdeFA V  
    GetCustomElement eID, entity A$@;Q5/2  
cpOt?XYR~  
    parID = FindFullName( "Geometry.Arizona Eye" ) #Pg#\v|7#>  
% G=cKM  
    ' Delete any shift(s) in z 6\7c:  
    count = 0 x {NBhq(4  
    While GetOperationCount(eID)>count .) Ej#mk  
        GetOperation eID, count, op hQ|mow@Zmz  
        If op.Type="ShiftZ" Then Ic0Sb7c  
            DeleteOperation eID,count %tVU Rj  
            count=count-1 + +L7*1t  
        End If "&={E{pQ  
        count=count+1 DSLX/uo1  
    Wend =p;cJ%#2]'  
|Y!^E %*  
    'Set new shift in d ~M;  
    op.Type = "ShiftZ" )]fiyXA  
    op.val1 = taq *ak0(yLn)  
    op.parent = parID ZD&F ,2v  
    AddOperation eID, op RnH?95n?{  
    Print "Set aqueous humor thickness = " & taq-0.55 L/u|90)L  
d#T5=5#  
    '************************************************************************* No7-fX1B  
    'Radius and conic constant of anterior lens R[m-jUL  
    '************************************************************************* ?$/::uo  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 7rdmj[vu  
    GetConic eID, entity, curv, conic %NkiYiA  
)xcjQkb  
    SetConic eID, entity, 1/Rant, CCant ;T
^s&/>E  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant h ;uzbu  
)|=1;L  
    '************************************************************************* ^|MS2'  
    'Radius and conic constant of posterior lens G u`xJ  
    '************************************************************************* @K]`
!=vUk  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +<\LY(o  
    GetConic eID, entity, curv, conic j55_wx@cA  
4pL'c@'  
    SetConic eID, entity, 1/Rpost, CCpost z- q.8~Z  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3Ws(],Q  
}Cu:BD.zQ  
    '************************************************************************* Y7S1^'E 3  
    'Lens thickness (Position of posterior lens surface) o`CM15d*7o  
    '************************************************************************* #K^hKx9  
5mAb9F8@  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) x;W!sO@$  
tpSgbGzp  
    ' Delete any z-shift(s) )cH\i91  
    count = 0 XgxO:"B  
    While GetOperationCount(eID)>count p.:|Z-W$  
        GetOperation eID, count, op N #v[YO`.  
        If op.Type="ShiftZ" Then yq.@-]ytZ  
            DeleteOperation eID,count "7sv@I_j  
            count=count-1 Qy9_tvq X  
        End If B9"d7E#wHF  
        count=count+1 l=xG<)Okb  
    Wend q#j[0,^ $  
L$Z!  
    'Set new z-shift \8#[AD*@s2  
    op.Type = "ShiftZ" ILCh1=?{9r  
    op.val1 = tlens <J d!`$  
    op.parent = parID l'l&Zqd  
    AddOperation eID, op 46vC/  
    Print "Set lens thickness = " & tlens fOMaTnm'  
p{oz}}  
    '************************************************************************* vs8[352  
    'Lens index of refraction -Jd

7  
    '************************************************************************* |gV~U~A]  
    eID = FindMaterial( "Lens" ) F+Kju2  
    GetModelMaterial eID, mat OX.5olb  
yPmo1|'X>d  
    mat.Nd = nlens \2u7>fU!  
    SetModelMaterial eID, mat &</)k|.A6\  
    Print "Set lens index of refraction = " & nlens 1a9' *[  
-)%\$z  
    '************************************************************************* Sck!w 3  
    'Pupil diameter Vw;iE=L  
    '************************************************************************* O=}w1]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) C+\z$/q  
^%*qe5J  
    'Adjust pupil diameter (trimming volume inner hole) A23K!a2u&  
Hva!6vwO%O  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Zs^zD;zU  
t_ CMsp  
    ' Adjust pupil location to just in front of the lens (f"Qz~R|6_  
    parID = FindFullName( "Geometry.Arizona Eye" )  @mw1__?  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ecm+33C  
    count = 0 BUZ74  
    While GetOperationCount(eID)>count $Ud9v4  
        GetOperation eID, count, op 53/$8=  
        If op.Type="ShiftZ" Then jA8Bmwt;w  
            DeleteOperation eID,count mmwc'-jU:  
            count=count-1 ;|T|*0vY[  
        End If Kez0Bka  
        count=count+1 s]yZ<uA  
    Wend euY+jc%  
    op.Type = "ShiftZ" w*'DlP<7  
    op.val1 = taq-0.01 \aSc2Ml]3n  
    op.parent = parID <Y /3U  
    AddOperation eID, op 0F uj-q  
=WN8><K!  
    Print "Set pupil diameter = " & pupilDiam %D-!<)z  

`!N.1RP _  
    'Update AZ Eye subassembly Description vy [7I8f{  
    eID = FindFullName( "Geometry.Arizona Eye" ) -DGuaUU  
    GetEntity eID, entity yo5-x"ze  
    entity.Description = "Accommodation = " & A & "D" #U'}g *  
    SetEntity eID, entity CWZv/>,%  
e8SAjl"}  
    Update \B 8j9  
    Print "DONE!" 
`?&C5*P  
     "@ZwDg`  
End Sub LB7$&.m'B  
@ #J2t#  
如果屈光度是4，光瞳直径是4，则会输出如下数据： Q_/UC#I8  
DM6(8df(  
Accommodation = 4 Diopters 9XUYy2{G  
Pupil Diameter = 4 mm z+fy&NPl  
Set aqueous humor thickness = 2.81 l [ m_<1L  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ;|=5)KE  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Qt"jU+Zoy  
Set lens thickness = 3.927 ~A/vP-  
Set lens index of refraction = 1.42672 Yk{4 3yw  
Set pupil diameter = 4 Y}}1]}VIK  
DONE! 1.2qh"#