[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ;`#R9
\C=h  
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。 7v%c.  
V,_m>$Mo  
模型 tsc`u>  
p?Azn>qBa  
模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 VQla.Y  
EpAgKzVpJ  
d>hv-nD  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 2DCQ5XewYe  
.}!.4J%q2  
光源 Gc|)4c  
*z0d~j*W;  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 gY~r{  
uMg\s\Z  
Gk
Jcd;  
Ax=HDW}  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 %rptI$^*X  
0ae8Xm3J@R  
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。 (P)G|2=  
.ImaM  
Tzex\]fw  
B`}um;T#~,  
视网膜的散射 ~w>h#{RB  
2 kDsIEA  
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。 J3_aHI  
@yuiNj.T  
y>a?<*Y+e  
_B^zm-}8|B  
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。 n"EKVw7Y  
$6"(t=%{  
F^O83[S  
jfuHZ^YA  
脚本 aas.-NT  
.Fn|Okn^gr  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： +Y%6y]8  
glMHT,  
OldOc5D  
_>- D*l  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 ;/K2h_=3z  
余下的脚本计算与屈光度有关的所有参数。 Z4] n<~o  
P3_.U8g$r  
分析 <sH}X$/  
w"^h<]b  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ^LMgOA(7  
cl~Yx4  
XNJ4T]><  
脚本代码 1^\w7Rew2  
$m4-^=  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. \/NF??k,jk  
T D_@0Rd  
Dim entity As T_ENTITY Q7s@,c!m_  
Dim op As T_OPERATION  js_`L#t  
Dim mat As T_MODELMATERIAL [oLV,O|s|j  
Dim A As Double MYAt4cHc2  
Dim pupilDiam As Double WTvUz.Et  
Dim eID As Long qyH-Z@  
Dim parID As Long YFO{i-*q  
Dim count As Integer `geHSx_  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }E 'r?N  
Dim tlens As Double, nlens As Double B 71/nt9  
Dim curv As Double, conic As Double 3A#Tn7  
Dim ok As Long `%C-7D'?  
<S@jf4  
Sub Main Wc3z7xK1@  
H9cPtP~a)  
    '用户输入对话框 P$)g=/td1  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ^Bx[%  
        TextBox 220,21,40,21,.TextBox1 'default: 0 jJ,_-ui  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 fO*jCl  
        OKButton 40,91,90,21 QZ a.c  
        CancelButton 190,91,90,21 '/W$9jm  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 P
MzPj,  
        TextBox 220,49,40,21,.TextBox2 'default: 4 yayhL DL  
    End Dialog c3vb~l)  
    Dim dlg As UserDialog %MHb  
Y=Vbs x  
    ok = Dialog (dlg) ~^mUu`@r  
/)P}[Q4  
    If ok=0 Then    'cancel button was pressed y~SVD@  
        Print "Execution cancelled." COrk (V  
        End ~3&{`9Y  
    End If :KLXrr  
}#XFa#  
    'Assign accommodation and pupil diameter & use defaults if field left empty Jup)m/  
    If dlg.TextBox1 = "" Then 4QL>LK  
        A = 0           'Default accommodation d1j9{  
    Else E[H  
        A = CDbl(dlg.TextBox1) x$Dq0FX!%_  
    End If =&HLz 7|  
,^(]zZh  
    If dlg.TextBox2 = "" Then mDB  
        pupilDiam = 4   'Default pupil diameter 'Uok<;
 
    Else LFp "Waiv  
        pupilDiam = CDbl(dlg.TextBox2) M^FY6TT4O  
    End If #+I'V\[  
IrLGAQ0  
    Print " " rwm^{Qa  
    Print "Accommodation = " & A & " Diopters" C-'hXh;hQ  
    Print "Pupil Diameter = " & pupilDiam & " mm" }lJ;|kx$  
bzgC+yT  
    ' Calculate new parameters with accommodation zG!nqSDG  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness }U_ '7_JT  
"t@p9>  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 8%?y)K^ D  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens {@Mr7*u  
[Kgb#L'{  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens uV/5f#)  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens &p0e)o~Ux  
UO/sv2CN  
    tlens = 3.767 + 0.04*A                  'Lens thickness VtreOJ+  
je4l3Hl  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction .g*j]!_]  
@f!X%)\;x  
    'Adjust parameters to account for accommodation okNo-\Dh!  
sp9gz~Kq
 
    '************************************************************************* -N *L1Zj  
    'Aqueous thickness (Position of Lens) eI #Gx_mg  
    '************************************************************************* P]E-Wp'p  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) QrZ#<{,J5  
    GetCustomElement eID, entity  C0rf  
n
y={OhP-  
    parID = FindFullName( "Geometry.Arizona Eye" ) ~Bd=]a$mj  
H}@:Br
i  
    ' Delete any shift(s) in z 2G8pDvBr  
    count = 0 eim+oms  
    While GetOperationCount(eID)>count C@rGa
7  
        GetOperation eID, count, op .R9Z$Kbq  
        If op.Type="ShiftZ" Then U, 6iT  
            DeleteOperation eID,count niVR!l  
            count=count-1 I`>U#x*  
        End If '`];=QY9pg  
        count=count+1 B@,9Cx564  
    Wend y4V:)@P  
v*;d  
    'Set new shift in /r}L_wI  
    op.Type = "ShiftZ" :Mf"  
    op.val1 = taq 6Rd4waj_,U  
    op.parent = parID 9 _d2u#  
    AddOperation eID, op iyskAD
S  
    Print "Set aqueous humor thickness = " & taq-0.55 EeIDlm0o  
IRdt:B|@  
    '************************************************************************* ~MpikBf  
    'Radius and conic constant of anterior lens J 3!~e+wn  
    '************************************************************************* *[Hrbln  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) XQ}Zr/f6  
    GetConic eID, entity, curv, conic S{YzHK  
)Q)qz$h@  
    SetConic eID, entity, 1/Rant, CCant ~j0rORy]  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant *bkb-nKw  
IThd\#=  
    '************************************************************************* @KG0QHyiU  
    'Radius and conic constant of posterior lens t6+m` Kq  
    '************************************************************************* _IH" SVub  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) yPyu)  
    GetConic eID, entity, curv, conic ?J[3_!"t  
xO$P C,  
    SetConic eID, entity, 1/Rpost, CCpost >r.]a`  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 0.aXg"  
'CLZ7pV  
    '************************************************************************* L`NIYH<^  
    'Lens thickness (Position of posterior lens surface) _k-_&PR  
    '************************************************************************* xNz(LZ.c  
W,q @ww u  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) M5xJ_yjG  
8:cbr/F<  
    ' Delete any z-shift(s) #6sz@XfV  
    count = 0 !Sq<_TO  
    While GetOperationCount(eID)>count Hl*v
S  
        GetOperation eID, count, op 6&3,fSP  
        If op.Type="ShiftZ" Then =:W2NN'  
            DeleteOperation eID,count DA=!AK>  
            count=count-1 $KHm5*;nd  
        End If xn8KOwX%  
        count=count+1 Obdn#Wm=  
    Wend \1EuHQ?  
<,d550GSm  
    'Set new z-shift
Bous d  
    op.Type = "ShiftZ" SnCwoxK  
    op.val1 = tlens nhI+xqfn  
    op.parent = parID  U'jt'(  
    AddOperation eID, op _=v#"l  
    Print "Set lens thickness = " & tlens t0)1;aBZ  
H`EhsYYK  
    '************************************************************************* QV4|f[Ki%  
    'Lens index of refraction ?vXgHDs^T  
    '************************************************************************* Lp`.fn8Ln  
    eID = FindMaterial( "Lens" ) lH-VqkR\  
    GetModelMaterial eID, mat s.3"2waZ=T  
!oLn=  
    mat.Nd = nlens {I
#_0Q,i  
    SetModelMaterial eID, mat ]TV_p[L0B  
    Print "Set lens index of refraction = " & nlens O&%'j  
16NHzAQ  
    '************************************************************************* V>6klA}o
 
    'Pupil diameter p8Vqy-:  
    '************************************************************************* fv+]iK<{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) -Cf)`/  
.35(MFvq!  
    'Adjust pupil diameter (trimming volume inner hole) ~uQ*u.wi  
=~^b  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" -YoL.`s1  
%"RJi?  
    ' Adjust pupil location to just in front of the lens )ycI.[C  
    parID = FindFullName( "Geometry.Arizona Eye" ) N['DqS =  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) LG}{ibB  
    count = 0 k %I83,+  
    While GetOperationCount(eID)>count bWPsfUn#  
        GetOperation eID, count, op N:j7J  
        If op.Type="ShiftZ" Then &AiAd6  
            DeleteOperation eID,count {QG.> lB  
            count=count-1 F>;Wbk&[|  
        End If osV6=  
        count=count+1  A l[ZU  
    Wend A#U! KX  
    op.Type = "ShiftZ" #~0Nk6*u  
    op.val1 = taq-0.01 *Pm
Zqe  
    op.parent = parID wMa8HeBE\  
    AddOperation eID, op |r9<aVlK  
.Rr^AGA4  
    Print "Set pupil diameter = " & pupilDiam TrI+F+;  
#UGSn:D<i  
    'Update AZ Eye subassembly Description mc{z  
    eID = FindFullName( "Geometry.Arizona Eye" ) c3]t"TA,  
    GetEntity eID, entity '%$Vmf)=  
    entity.Description = "Accommodation = " & A & "D" )
f?I{  
    SetEntity eID, entity +p u[JHF  
>%/x~UFc5  
    Update E@VQxB7+  
    Print "DONE!" ?m7:@GOE1  
     )~2\4t4|g  
End Sub S-t#d7'B  
YQ0#j'}/  
如果屈光度是4，光瞳直径是4，则会输出如下数据： 5es t  
Ek+R  
Accommodation = 4 Diopters y)kxR  
Pupil Diameter = 4 mm 6w.E Sm  
Set aqueous humor thickness = 2.81 RhWQ:l]  
Set anterior lens radius = 10.4 and conic constant = -2.375869 {}$9 70y  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 4uF.kz-cg  
Set lens thickness = 3.927 :saP :&  
Set lens index of refraction = 1.42672 W>3S%2d  
Set pupil diameter = 4 ch i=]*9  
DONE! @SfQbM##%  
7q0_lEh