[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 nEd M_JPv  
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。 4Hml.|$  
L7Qo-  
模型 s`#ntset0  
gj[ >p=Wn  
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。 m)@Q_{=6M  
rkfQr9Vc  
6; 5)/q  
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. +MNSZLP]  

56Sh  
光源 p*pn@z  
0 OAqA?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。 ^V<J69ny|9  
MUbhEau?  

n5bXQ  
W>Mse[6`c  
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。 oUQGLl!V  
b&=]S(  
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。 #D`S  
DC|xilP1O  
vIVw'Z(g}  
E\R raPkQT  
视网膜的散射 _YH<YOrMh  
-l-AToO4  
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。 FNz84qVIx'  
*>e~_{F  
6Cl+KcJH  
<\, &:<  
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。 rD0k%-{{  
@Pxw
hlxa  
:v#k&Uh3y  
e
> ar  
脚本 iD%qy/I/  
'1CD- Bu  
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： GhqgRzX  
4)c+t"h  
[urH a  
LKqRvPnh  
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。 ZJ^s}  
余下的脚本计算与屈光度有关的所有参数。 yDd=& T   
"0|BoG  
分析 /K_ i8!y  
HR[Q ?rg  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 o*%3[HmV  
GS}0;x  
\4OK!6LkI  
脚本代码 n<{
aPLQ  
8]My k>  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. -&trk  
Dp!;7e s|  
Dim entity As T_ENTITY S\B5&W  
Dim op As T_OPERATION "YuZ fL`bb  
Dim mat As T_MODELMATERIAL De;,=BSp  
Dim A As Double "\`>2  
Dim pupilDiam As Double LL{t5(- _  
Dim eID As Long v-ThdE$G#  
Dim parID As Long 9U]pH%.9  
Dim count As Integer >P(eW7RL  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double wOjv[@d  
Dim tlens As Double, nlens As Double !loO%3_)  
Dim curv As Double, conic As Double e:qo_eSC^-  
Dim ok As Long w]n4KR4  
M6\7FP6G  
Sub Main h>dxBN  

8,=G1c  
    '用户输入对话框 xYmdCf@H  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 E\w+kAAf  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Fl<
(m  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 <R>Q4&we(  
        OKButton 40,91,90,21 77``8,  
        CancelButton 190,91,90,21 %Hh3u$Y,  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :#Ty^-"]1  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Pfm*<,'x"[  
    End Dialog vsH3{:&;"P  
    Dim dlg As UserDialog n-d:O\]  
VW{,:Ya  
    ok = Dialog (dlg) Ga.0Io&}C  
Cgo9
rC~]  
    If ok=0 Then    'cancel button was pressed S:#e8H_7m]  
        Print "Execution cancelled." M]1;  
        End C]/&vh7ta  
    End If 1XCmMZ  
O"qR}W  
    'Assign accommodation and pupil diameter & use defaults if field left empty HQl~Dh0DJ  
    If dlg.TextBox1 = "" Then \OP9_J(*  
        A = 0           'Default accommodation uw_H:-J  
    Else !Pw$48cg  
        A = CDbl(dlg.TextBox1) ]s_@n!  
    End If goB;EWz  
+Jdm#n?_  
    If dlg.TextBox2 = "" Then w3d34*0$  
        pupilDiam = 4   'Default pupil diameter o,J^ e_  
    Else mdaYYD=c%  
        pupilDiam = CDbl(dlg.TextBox2) G&jZ\IV  
    End If B.}cB'|  
zLL)VFCJW  
    Print " " ]Ym=+lgi  
    Print "Accommodation = " & A & " Diopters" BO"qD[S  
    Print "Pupil Diameter = " & pupilDiam & " mm" g*F~8+]Y  
+|9f%f6vp  
    ' Calculate new parameters with accommodation 6i| ~7md,  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ZEqE$:  
9l#gMFknI  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens s047"Q  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens @*SA$9/l  
l:)S 3  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens zXjwnep  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 7u|%^Ao6  
"ct58Y@  
    tlens = 3.767 + 0.04*A                  'Lens thickness -n-Z/5~ X  
?T <rt  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction FJ}gUs{m  
JDKLKHOMZ  
    'Adjust parameters to account for accommodation eKyqU9  
^iuo^
2+  
    '************************************************************************* %P;[fJ `G  
    'Aqueous thickness (Position of Lens) :kt/$S^-  
    '************************************************************************* t|_{;!^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) a5)JkC  
    GetCustomElement eID, entity 3[.3dy7,Z  
~pRs-  
    parID = FindFullName( "Geometry.Arizona Eye" ) :mP9^Do2;  
_CL
{IY  
    ' Delete any shift(s) in z 6`Lc
s
  
    count = 0 $cu]_gu  
    While GetOperationCount(eID)>count L?Cjo4xS  
        GetOperation eID, count, op hVkO%]?  
        If op.Type="ShiftZ" Then =-5[Hn%  
            DeleteOperation eID,count M|H2kvl  
            count=count-1 ~3d*b8  
        End If (7~%B"  
        count=count+1 7VY8CcL  
    Wend #Skj#)I"  
m@[3~ 6A  
    'Set new shift in S}b~_}  
    op.Type = "ShiftZ" ;P8(Zf3wJb  
    op.val1 = taq dWUUxKC  
    op.parent = parID {m'AY)  
    AddOperation eID, op +!><5  
    Print "Set aqueous humor thickness = " & taq-0.55 \FXp*FbQ  
)P%4:P  
    '************************************************************************* '-.
wFB;  
    'Radius and conic constant of anterior lens {!r#f(?uT  
    '************************************************************************* h;nQxmJ9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 7DZTQUb"  
    GetConic eID, entity, curv, conic JRo;(wqZ  
q~M2:SN@X  
    SetConic eID, entity, 1/Rant, CCant +KP_yUq[  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant jqtVpNwM  
86qcf"?E  
    '************************************************************************* (kY@7)d'e  
    'Radius and conic constant of posterior lens ol
}`Wwy  
    '************************************************************************* %I0}4$  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ]'g:B p  
    GetConic eID, entity, curv, conic Fpf><Rn  
QAUykS8  
    SetConic eID, entity, 1/Rpost, CCpost (0}j]p'w  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost zofx+g\(W  
7@3sUA_Go  
    '************************************************************************* [8z&-'J=  
    'Lens thickness (Position of posterior lens surface) +q-c8z  
    '************************************************************************* sG1BNb_  
c=aO5(i0  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) t\%%d)d9  
[T]Bfo  
    ' Delete any z-shift(s) d"GDZ[6  
    count = 0 m9!DOL1pl  
    While GetOperationCount(eID)>count Ld~q1*7J  
        GetOperation eID, count, op Wn~ZA#  
        If op.Type="ShiftZ" Then bw5T2wYZ  
            DeleteOperation eID,count S<pk
c8  
            count=count-1 mLaCkn
  
        End If 7>&1nBh. f  
        count=count+1 tR;{.  
    Wend &mdB\Y?^  
=x#&\ui  
    'Set new z-shift IM]h*YV'  
    op.Type = "ShiftZ" dN0mYlu1|  
    op.val1 = tlens [4\aYB9N  
    op.parent = parID 6klD22b2$  
    AddOperation eID, op n.ct]+L  
    Print "Set lens thickness = " & tlens  Fs)  
snq;:n!  
    '************************************************************************* :q;R6-|.  
    'Lens index of refraction Gk 6fO  
    '************************************************************************* ?Q?598MC  
    eID = FindMaterial( "Lens" )
--A&TV  
    GetModelMaterial eID, mat 7H#2WFQ7  
b!,j
a?  
    mat.Nd = nlens  J `x}{K  
    SetModelMaterial eID, mat BUDGyl/=  
    Print "Set lens index of refraction = " & nlens 5{>>,pP&  
{#9,j]<  
    '************************************************************************* ;h9W\Se  
    'Pupil diameter tUv3jq)n%  
    '************************************************************************* RJwb@r<v  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) D:)~%wu Lt  
`@MPkCy1  
    'Adjust pupil diameter (trimming volume inner hole) \OA L Or  
Q0WY$w1<  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" K( z[}  
3fl7~Lw,  
    ' Adjust pupil location to just in front of the lens _aY.  
    parID = FindFullName( "Geometry.Arizona Eye" ) :G0+;[?N  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) V]m^7^m3  
    count = 0 YuA7r"c  
    While GetOperationCount(eID)>count 0-GKu d  
        GetOperation eID, count, op L20rv:W$h  
        If op.Type="ShiftZ" Then %p*`h43;  
            DeleteOperation eID,count C#h76fpH  
            count=count-1 g<\>; }e  
        End If sjb-Me?  
        count=count+1 1@@y]s_.a  
    Wend 6i-*N[!U  
    op.Type = "ShiftZ" "f<#.}8  
    op.val1 = taq-0.01 G:DSWW}  
    op.parent = parID .*:h9AE7vo  
    AddOperation eID, op jr:drzr{I  
*w|iu^G  
    Print "Set pupil diameter = " & pupilDiam RQ|?Ce",  
K.%z;(U  
    'Update AZ Eye subassembly Description ?Nu#]u-  
    eID = FindFullName( "Geometry.Arizona Eye" ) &1~Re.*B  
    GetEntity eID, entity v4D!7t&v"  
    entity.Description = "Accommodation = " & A & "D" j3LNnZY  
    SetEntity eID, entity Y&:/~&'  
L\YZT| K(  
    Update @ct#s:t  
    Print "DONE!" c8q G\\t[  
     Bd

8hJA  
End Sub 9\:w8M X'  
_Qg{ ;  
如果屈光度是4，光瞳直径是4，则会输出如下数据： C[g&F0 6  
Xj(>.E{~H  
Accommodation = 4 Diopters 
Lg b  
Pupil Diameter = 4 mm jOtzx"/)rE  
Set aqueous humor thickness = 2.81 6# R;HbkO  
Set anterior lens radius = 10.4 and conic constant = -2.375869 B6uf;Yc  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Rd0?zEKV  
Set lens thickness = 3.927 T%w(P ^qk  
Set lens index of refraction = 1.42672 =@%MV(  
Set pupil diameter = 4 0OEtU5lf`y  
DONE! F=VoFmF@  
ONNW.xHp