[技术]Arizona眼睛模型 [复制链接]

简介 0fn
ZR$PB  
i[^k.W3gf  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 8W-]t1O%!  
]@*tfz\YaH  
模型 TT|-aS0l(u  
b\1+kB/8  
模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 {V[Ha~b%*  
k?^%hO>[  
4$%`Qh>yA  
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. _kh>Z  
9n_ eCb)H  
光源 (tJ91SBl  
"VV914*z  
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。 +jc
df}  
^[en3aQ  
NeY"6!;k  
r k@UsHy  
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。 'yE*|Sx  
LlU'
_}>  
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。 BApa^j\?  
*7\W=-  

8,=G1c  
pw!@Q?R  
视网膜的散射 l x7Kw%  
Q5g,7ac8L  
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。 m6-76ma,hi  
b<\$d4Qy  
YQ52~M0L  
w.tW=z5  
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。 j?( c}!}  
p[u4,  
_ ~|Q4AJ  
?k"0w)8  
脚本 `%uK0qw"  
R^w}o,/  
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： .U<F6I:<md  
D{>\-]\  
^ZR8s^X  
97!H`|u <  
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。 ^=k{~  
余下的脚本计算与屈光度有关的所有参数。 (X*9w##x(  
bCzdszvg3  
分析 1ADv?+j)A/  
+mi
R3~w.  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 gd K*"U  
Gp,'kw"I  
7g5@vYS+  
脚本代码 |!oXvXU  
o'96ON0  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. Y5n>r@)m  
%w$mSG  
Dim entity As T_ENTITY KhrFg1|  
Dim op As T_OPERATION 
f -7S:,  
Dim mat As T_MODELMATERIAL of=ql  
Dim A As Double |e:rYLxm:  
Dim pupilDiam As Double h<)yJh  
Dim eID As Long bTiBmS  
Dim parID As Long 5\&]J7(  
Dim count As Integer O)`Gzx*ShU  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double A0OB$OK  
Dim tlens As Double, nlens As Double 3
tF:  
Dim curv As Double, conic As Double i$["aP~G  
Dim ok As Long 2qlIy  
T
ywK\hH  
Sub Main Si]X rub  
bH,M,xIL2  
    '用户输入对话框 6(>WGR
 
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 |WBZN1W)  
        TextBox 220,21,40,21,.TextBox1 'default: 0 7/ t:YBR  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 p.5e: i^LJ  
        OKButton 40,91,90,21 ~{$L
9;x  
        CancelButton 190,91,90,21 Sj@15 W  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 12-EDg/1  
        TextBox 220,49,40,21,.TextBox2 'default: 4 @gEr+O1K(  
    End Dialog W/=7jM   
    Dim dlg As UserDialog ~@@ Z|w  
%XR<isn  
    ok = Dialog (dlg) >;7a1+`3  
i\ "{#  
    If ok=0 Then    'cancel button was pressed 5/,Qz>QE[  
        Print "Execution cancelled." pjdo|  
        End @+E7w6>%  
    End If bM^7g  
i&*<lff  
    'Assign accommodation and pupil diameter & use defaults if field left empty ?^. Pt  
    If dlg.TextBox1 = "" Then 5#2jq<D  
        A = 0           'Default accommodation 2qjyFTT  
    Else uRpBeH]Z"  
        A = CDbl(dlg.TextBox1) l|7O)  
    End If 14-]esSa  
<S&]$?`{Wi  
    If dlg.TextBox2 = "" Then %jTw  
        pupilDiam = 4   'Default pupil diameter  E>"8/  
    Else 5D L,U(Y  
        pupilDiam = CDbl(dlg.TextBox2) [[X+P 0`r  
    End If ;Yv14{T!  
M9DgO4xl  
    Print " " h1*FPsc  
    Print "Accommodation = " & A & " Diopters" ;?`@"YG)  
    Print "Pupil Diameter = " & pupilDiam & " mm" ,Y-S
(  
ntZ~m  
    ' Calculate new parameters with accommodation &r:=KT3  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness %{"dP%|w4}  
?<6@^X"  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens lC4PKmno  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens bS%C?8  
qlvwK&W<QM  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &Sa~/!
M  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Fpf><Rn  
QAUykS8  
    tlens = 3.767 + 0.04*A                  'Lens thickness 1mix+.d  
zofx+g\(W  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 7@3sUA_Go  
p#=;)1  
    'Adjust parameters to account for accommodation ^cn@?k((A  
a'A s
 
    '************************************************************************* U!Mf]3  
    'Aqueous thickness (Position of Lens) mV;3ILO  
    '************************************************************************* m1V-%kUI  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^vaL8+  
    GetCustomElement eID, entity t}~UYG(h~  
!-,Ww[G>  
    parID = FindFullName( "Geometry.Arizona Eye" ) x_W3sS]ej  
Wc\+x1:8  
    ' Delete any shift(s) in z #R<G,"N5  
    count = 0 &F`L}#oL&  
    While GetOperationCount(eID)>count z7k$0&  
        GetOperation eID, count, op In+^V([u+_  
        If op.Type="ShiftZ" Then KSsWjF}d  
            DeleteOperation eID,count O5OXw]  
            count=count-1 (Vap7.6;_  
        End If cmIT$?J  
        count=count+1  p[Hr39o  
    Wend {2EMz|&8  
JhH`uA&  
    'Set new shift in yzg9I  
    op.Type = "ShiftZ" p&O8qAaO  
    op.val1 = taq -=sf}4A  
    op.parent = parID {G%3*=?,j  
    AddOperation eID, op
--A&TV  
    Print "Set aqueous humor thickness = " & taq-0.55 [S)G$JW  
b!,j
a?  
    '*************************************************************************  J `x}{K  
    'Radius and conic constant of anterior lens BUDGyl/=  
    '************************************************************************* XmlIj8%9[&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {#9,j]<  
    GetConic eID, entity, curv, conic ;h9W\Se  
tUv3jq)n%  
    SetConic eID, entity, 1/Rant, CCant 'e85s%ru  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant D:)~%wu Lt  
`@MPkCy1  
    '************************************************************************* \OA L Or  
    'Radius and conic constant of posterior lens Wp`C:H  
    '************************************************************************* K( z[}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 3fl7~Lw,  
    GetConic eID, entity, curv, conic _aY.  
OGGSS&5tw  
    SetConic eID, entity, 1/Rpost, CCpost V]m^7^m3  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost YuA7r"c  
0-GKu d  
    '************************************************************************* k,lqT>C  
    'Lens thickness (Position of posterior lens surface) AA2ui%  
    '************************************************************************* }7Jp :.qk  
RAwk7F3qn  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) #fN/LO  
XECikld>  
    ' Delete any z-shift(s) K-6p'|  
    count = 0 zWtj|%ts  
    While GetOperationCount(eID)>count /`}6rXnw9  
        GetOperation eID, count, op t2U$m'(A&  
        If op.Type="ShiftZ" Then =E1tgrW  
            DeleteOperation eID,count p7$3`t6u  
            count=count-1 7JS#a=D#  
        End If
8F)=n \  
        count=count+1 !?6.!2  
    Wend W8VO)3nmD  
?R282l  
    'Set new z-shift ET3,9+Gj  
    op.Type = "ShiftZ" 2^J/6R$  
    op.val1 = tlens U1jSUkqb  
    op.parent = parID GZS{
&w!  
    AddOperation eID, op [WYJrk.  
    Print "Set lens thickness = " & tlens wR(ttwxK3  
j C9<hLt  
    '************************************************************************* f}%sO  
    'Lens index of refraction DP0Z*8Ia  
    '************************************************************************* aoK4Du{  
    eID = FindMaterial( "Lens" ) soDfi-2o3  
    GetModelMaterial eID, mat kR_E6Fl  
1 0V+OIC  
    mat.Nd = nlens C`pan /t  
    SetModelMaterial eID, mat PK8V2Ttv  
    Print "Set lens index of refraction = " & nlens eWw y28t  
f@L\E>t  
    '************************************************************************* LPMb0F}"5  
    'Pupil diameter [RW,{A  
    '************************************************************************* 1&}G+y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) f!(cD80  
0$!.c~
  
    'Adjust pupil diameter (trimming volume inner hole) TZkTz P[  
dbd"pR8v  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" bu;vpNa  
[-QK$~[ g  
    ' Adjust pupil location to just in front of the lens 4">84,-N  
    parID = FindFullName( "Geometry.Arizona Eye" ) 9z5z  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) {8_:4`YZ  
    count = 0 :ECw \_"0$  
    While GetOperationCount(eID)>count 6mX:=Q  
        GetOperation eID, count, op  X+\0%|  
        If op.Type="ShiftZ" Then 8`6 LMQ  
            DeleteOperation eID,count 1/!nV  
            count=count-1 lf}?!*V`+  
        End If  POkXd^pI  
        count=count+1 Kgps_tY%  
    Wend ]D?oQ$q7  
    op.Type = "ShiftZ" 4U:DJ_GN  
    op.val1 = taq-0.01 k#BU7Exij  
    op.parent = parID 
2~+'vi  
    AddOperation eID, op N{|[R   
r*xq(\v  
    Print "Set pupil diameter = " & pupilDiam =xl7vHn7  
A-}PpH~.Z  
    'Update AZ Eye subassembly Description !:&2+%  
    eID = FindFullName( "Geometry.Arizona Eye" ) hl=oiUf[s  
    GetEntity eID, entity 54bF)<+  
    entity.Description = "Accommodation = " & A & "D" [qq`cT@  
    SetEntity eID, entity M,I68  
zjzqKdy}F  
    Update Z(#XFXd  
    Print "DONE!" zaQ$ Ht  
     Uzy;#q  
End Sub ^a: Saq-}  
@fUX
)zm>  
如果屈光度是4，光瞳直径是4，则会输出如下数据： &?&'"c{;m  
Be'?#Qe   
Accommodation = 4 Diopters `1}HWLBX.  
Pupil Diameter = 4 mm PpI+@:p[  
Set aqueous humor thickness = 2.81 &:IfhS  
Set anterior lens radius = 10.4 and conic constant = -2.375869 9N`+ O  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Fa Qu$q  
Set lens thickness = 3.927 _gis+f/8h  
Set lens index of refraction = 1.42672 [J(@$Qix  
Set pupil diameter = 4 })h'""i&xn  
DONE! uMljH@xBc