[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 [qO5~E`;  
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。 U]`'GM/x  
F:[Nw#gj/  
模型 b<2
9wL1  
wsdB; 6%$  
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。 !3b|*].B  
TsFV ;Sl3  
Qd&d\w/  
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. :V5!C$QV  
tS_xa  
光源 /h}wM6pg  
bn<I#ZH2  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 )sqp7["-  
~#IWM+I  
YG}p$\R  
U#UVenp@  
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。 mTrI""Jsu;  
8S[<[CH  
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。 @4W\RwD  
V
)WIfRs  
^-csi  
5~ *'>y  
视网膜的散射 >h/)r6  
it/C y\f  
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;S-ESQ  
:3E8`q~c1  
b3y,4ke"  
's7SZ$(  
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。 ^Xt]wl*]+  

jiw`i  
ATXx? b8h  
y$r?t0
 
脚本 FzsS~C$wH{  
@4  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： g O\f:Pg  
;k63RNT,M&  
^~YmLI4  
|+$j(
YuH  
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。 q)z1</B-  
余下的脚本计算与屈光度有关的所有参数。 v0H>iKh7  
6"rFfdns  
分析 BHRrXC\  
i+T0}M<  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 }ii]cY  
CpP$HrQ  
(-G(^Tn  
脚本代码 DY+8m8!4H  
a s<q  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7:R{
~|R  
[jtj~]&mO  
Dim entity As T_ENTITY 3Oig/KZ  
Dim op As T_OPERATION 6&xW9' 6b:  
Dim mat As T_MODELMATERIAL Jj^<:t5{rN  
Dim A As Double 5sV/N] !  
Dim pupilDiam As Double Ph7(JV{  
Dim eID As Long T$8$9D_u  
Dim parID As Long "`1of8$X7  
Dim count As Integer e&a[k  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double [2H(yLwO  
Dim tlens As Double, nlens As Double W<Vzd4hR  
Dim curv As Double, conic As Double iw]BQjK  
Dim ok As Long WY.\<$7  
hz~CW-47  
Sub Main qNQ3(1xW  
DHujpZXQ  
    '用户输入对话框 7yCx !P;  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 qwq+?fj={  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Wp9 2sm+  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 G~$M"@Q7N  
        OKButton 40,91,90,21 ]@<3 6ByM  
        CancelButton 190,91,90,21 |@bNd7=2d  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?PxYS%D_L  
        TextBox 220,49,40,21,.TextBox2 'default: 4 *mhw5Z=!  
    End Dialog RT+30Q?  
    Dim dlg As UserDialog f6_|dvY3  
lt(-,md  
    ok = Dialog (dlg) 4`5Qt=}  
Xy8ie:D  
    If ok=0 Then    'cancel button was pressed Vwh&^{Eh  
        Print "Execution cancelled." G>{:D'#  
        End !&:W1Jkp(  
    End If Z-sN4fr a  
$q
@RHcj  
    'Assign accommodation and pupil diameter & use defaults if field left empty dgqJ=+z 0y  
    If dlg.TextBox1 = "" Then 2Z9gOd<M~  
        A = 0           'Default accommodation `R=_t]ie  
    Else :>-sITeY  
        A = CDbl(dlg.TextBox1) 2] wf`9ZH  
    End If ZtK%b+MBP  
MUt^mu$86  
    If dlg.TextBox2 = "" Then wbF1>{/
"  
        pupilDiam = 4   'Default pupil diameter rxK[CDM,  
    Else [,?A
$Z*Z|  
        pupilDiam = CDbl(dlg.TextBox2) AiHDoV+-  
    End If wk <~Y 3u  
PNxO\Rc  
    Print " " Va[dZeoy  
    Print "Accommodation = " & A & " Diopters" Q\>SF  
    Print "Pupil Diameter = " & pupilDiam & " mm" )*<d1
$aM  
lG^nT  
    ' Calculate new parameters with accommodation 7)It1i-  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness (a4y1k t-  
D2*Q1n  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens DdZ_2B2  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens o6yZ@R  
hD.wKX?oO  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens i2R]lE8  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 5N</Z6f'o  
M #RuI%  
    tlens = 3.767 + 0.04*A                  'Lens thickness `0vy+T5  
kk./-G  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ?|rw=%  
[67f;?b  
    'Adjust parameters to account for accommodation M]zNW{Xt  
 G/;aZ  
    '************************************************************************* Z42Suy  
    'Aqueous thickness (Position of Lens) 0_Z|y/I
.  
    '************************************************************************* :qKY@-t7H  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZaV66Y>  
    GetCustomElement eID, entity ?U[nYp}"v  
~=]@],{  
    parID = FindFullName( "Geometry.Arizona Eye" ) Gkvd{G?F  
_[Wrd?Z  
    ' Delete any shift(s) in z 3T^dgWXEG  
    count = 0 >!.lr9(l  
    While GetOperationCount(eID)>count &zDFf9w2{  
        GetOperation eID, count, op p" W0$t.  
        If op.Type="ShiftZ" Then (j Q6~1  
            DeleteOperation eID,count '"p*FN  
            count=count-1 <g1hdF0  
        End If d'nuk#r  
        count=count+1 rSCX$ @@F  
    Wend B{7/A[$%C  
Mp}NUQHE  
    'Set new shift in ^u&Khc~ y  
    op.Type = "ShiftZ" ~4gKAD  
    op.val1 = taq $ aBSr1  
    op.parent = parID iz5wUyeg  
    AddOperation eID, op TTak[e&j3  
    Print "Set aqueous humor thickness = " & taq-0.55 lD=j/  
yp'>+cLa  
    '************************************************************************* JU+'UK630  
    'Radius and conic constant of anterior lens SytDo (_=W  
    '************************************************************************* V!tBipX%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) eV}Tx;1|}  
    GetConic eID, entity, curv, conic -%$ dFq  
}r<^]Q*&p  
    SetConic eID, entity, 1/Rant, CCant !sWB
j'[>  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant %+J*oFwQu  
k}qiIMdI  
    '************************************************************************* Av4E?@R  
    'Radius and conic constant of posterior lens .Q@'Ob`  
    '************************************************************************* Qn&^.e9I  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) J, >PLQAa  
    GetConic eID, entity, curv, conic 4u7>NQUDu  
bd;f@)X  
    SetConic eID, entity, 1/Rpost, CCpost /hR]aw  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost SXF_)1QO\W  
sUMn (@r  
    '************************************************************************* '~a$f;: Dv  
    'Lens thickness (Position of posterior lens surface) GQWTQIl
]  
    '************************************************************************* a}hM}U!  
b;ZAz  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) =_3qUcOP  
(j"MsCwE  
    ' Delete any z-shift(s) %W@IB8]Vr  
    count = 0 _@76eZd  
    While GetOperationCount(eID)>count feHAZ.8rp+  
        GetOperation eID, count, op YJsi5  
        If op.Type="ShiftZ" Then 6GvnyJ{[  
            DeleteOperation eID,count L@GD$F=<0  
            count=count-1 5(Oc"0''H  
        End If VHNiTp  
        count=count+1 [)u{-  
    Wend &|] ^ u/  
H4jqF~  
    'Set new z-shift A[a+,TN{  
    op.Type = "ShiftZ" . %7A
7a  
    op.val1 = tlens ;
O>fy:$'  
    op.parent = parID ?yK\L-ad  
    AddOperation eID, op H:6$)#  
    Print "Set lens thickness = " & tlens
:"]ei@  
}FVX5/.'  
    '************************************************************************* 1fZ:^|\  
    'Lens index of refraction HbVLL`06*  
    '*************************************************************************
BZ9iy~  
    eID = FindMaterial( "Lens" ) iSHl_/I<  
    GetModelMaterial eID, mat ?C3cPt"  
gZv<_0N  
    mat.Nd = nlens ]9Hy "#Fz  
    SetModelMaterial eID, mat EM}z-@A>  
    Print "Set lens index of refraction = " & nlens Z ngJ9js  
4fswx@l  
    '************************************************************************* K-3 _4As  
    'Pupil diameter g_U6
9 z  
    '************************************************************************* ev $eM  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) |{T2|iJI  
_L":Wux  
    'Adjust pupil diameter (trimming volume inner hole) T!bu}KO  

hLRQ)  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5,C,q%2  
CCV~nf  
    ' Adjust pupil location to just in front of the lens }|,y`ui\  
    parID = FindFullName( "Geometry.Arizona Eye" ) Hik[pVK@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) s9iM hCu|  
    count = 0 iq$/6!t  
    While GetOperationCount(eID)>count z{\.3G  
        GetOperation eID, count, op 4KCxhJq  
        If op.Type="ShiftZ" Then q]x@q  
            DeleteOperation eID,count tANG ]  
            count=count-1 ]_s]Q_+E  
        End If x<(h9tB  
        count=count+1 @^Oww(I  
    Wend s><co]  
    op.Type = "ShiftZ" &^.'g{\Y  
    op.val1 = taq-0.01 zlfm})+G  
    op.parent = parID 8{C3ijR  
    AddOperation eID, op $4&Ql  
q<VhP2R  
    Print "Set pupil diameter = " & pupilDiam |wDCIHzQ  
z( wXs&z;  
    'Update AZ Eye subassembly Description i(WWF#N5  
    eID = FindFullName( "Geometry.Arizona Eye" ) lK-I[i!  
    GetEntity eID, entity cc[w%jlA#  
    entity.Description = "Accommodation = " & A & "D" /03>|Juo  
    SetEntity eID, entity cF6|IlhO  
E'Bt1u  
    Update }1V&(#H2  
    Print "DONE!" C7{wI`~  
     ]l%j>Vb!L  
End Sub DjIs"5Iei  
Gkl#s7'  
如果屈光度是4，光瞳直径是4，则会输出如下数据： KjadX&JD  
p.G7Cs  
Accommodation = 4 Diopters >L%%B-  
Pupil Diameter = 4 mm XL:7$  
Set aqueous humor thickness = 2.81 !duR7a  
Set anterior lens radius = 10.4 and conic constant = -2.375869 b7-a0zaN  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 |fUSq1//  
Set lens thickness = 3.927 ?Rdi"{.wI  
Set lens index of refraction = 1.42672 <~dN23)  
Set pupil diameter = 4 4:.M*Dz  
DONE! wQ5__"D  
$)U RY~;i