[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 Y'~&%|9+T  
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。 Smux&e  
`->k7a0<b1  
模型 m{y
ON&y  
!58JK f  
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。 !Ch ya  
4>HGwk@+8  
?(=
B=a[  
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. ?!66yn  
|Wgab5D>V  
光源 ,'6GG+  
?n+\T'f!  
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。 6;*(6$;  
c2f$:XiM  
`7A@\Ha3  
F&~vD  
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。 G<
eJ0S  
FHC7\#p/9Z  
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。 qQ'@yTVN  
7q=0]Hrg(D  
yB1>83!q  
AVWrD[ wD2  
视网膜的散射 \nWpV7TSN  
"lZ<bG  
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。 n58jB:XR(  
ZB%~>  
g <o;\\  
)]R?v,9*D  
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。 0}V'\=F454  
B$Z!E%a;  
#w@Pa L iS  
]l'ki8  
脚本 DeSTo9A}!  
nE;gM1I  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 6f!mk:\T.  
h_L '_*  
pH[lj8S  
Biy 9jIWI  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 W!X]t)Ow  
余下的脚本计算与屈光度有关的所有参数。 lz 6 Aj  
PgAfR:Y!  
分析 zY+Et.lg]^  
V1`|j  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 -pu\p-Z  
9a%@j ]  
Z(M)2  
脚本代码 eHe /w9`$R  
)}!'VIe^!  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. Uzn|)OfWP  
!.$P`wKr  
Dim entity As T_ENTITY dCTpO  
Dim op As T_OPERATION &7&*As  
Dim mat As T_MODELMATERIAL T}[vfIJD  
Dim A As Double 5I,X#}K[  
Dim pupilDiam As Double {;DZ@2|  
Dim eID As Long :,,y63-f4  
Dim parID As Long %ko 8P  
Dim count As Integer L?+|%[  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double VBJ]d
|  
Dim tlens As Double, nlens As Double vq7%SEkES  
Dim curv As Double, conic As Double j//wh1  
Dim ok As Long #.YcIR)  
qL.Y_,[[  
Sub Main ^)l@7XxD  
T+h{Aeg  
    '用户输入对话框 zEfD{I  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 H>iZVE  
        TextBox 220,21,40,21,.TextBox1 'default: 0 D.R  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |qDfFGYf  
        OKButton 40,91,90,21 SVh4)}.x  
        CancelButton 190,91,90,21 guXpH
F=  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9[E$>o"%  
        TextBox 220,49,40,21,.TextBox2 'default: 4 kw ^ Sbxm  
    End Dialog E]?HCRa5R  
    Dim dlg As UserDialog /,Id_TTCO  
%
esZ}U  
    ok = Dialog (dlg) G%R`)Z]8&  
Bjj^!T/#  
    If ok=0 Then    'cancel button was pressed L6=RD<~C  
        Print "Execution cancelled." G%jJ>T4  
        End r~_ /Jj  
    End If +STzG/9#  
E*CQG;^=N  
    'Assign accommodation and pupil diameter & use defaults if field left empty 3#9r4;&  
    If dlg.TextBox1 = "" Then ]u ~Fn2  
        A = 0           'Default accommodation 4$GRCq5N;  
    Else [<a%\:c m4  
        A = CDbl(dlg.TextBox1) @b\_696.  
    End If E(+wl  
N:jiZ)  
    If dlg.TextBox2 = "" Then T8TsKjqOZ  
        pupilDiam = 4   'Default pupil diameter <?Izfl6  
    Else ~.`r(  
        pupilDiam = CDbl(dlg.TextBox2) N/{Yi _n  
    End If ~LW%lMy;^|  
Le:mMd= G  
    Print " " 7h&`BS  
    Print "Accommodation = " & A & " Diopters" '=G Ce%A  
    Print "Pupil Diameter = " & pupilDiam & " mm" 0+y~RTAVB  
tF
g'RV{  
    ' Calculate new parameters with accommodation ^_h
7!=W  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Zi
@+T  
xjq7%R_,  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ~2DV{dyj  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Q<-%jBP  
y&=19A#  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 8Pr7aT:,  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens l%U_iqL&  
(My$@l973  
    tlens = 3.767 + 0.04*A                  'Lens thickness yP9wYF^A\  
S@zkoj@  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction UQ?OD~7  
g74z]Uj.B  
    'Adjust parameters to account for accommodation r
jQhU%zv  
Cm<j*Cnl  
    '************************************************************************* ~ 9~\f  
    'Aqueous thickness (Position of Lens) \j})Ku
l  
    '************************************************************************* o"}&qA;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) B"Kce"!  
    GetCustomElement eID, entity 
po2[uJ  
5h=TV  
    parID = FindFullName( "Geometry.Arizona Eye" ) q(tGbhQ  
OC>_=i$'  
    ' Delete any shift(s) in z r{2].31'  
    count = 0 $EGRaps{j>  
    While GetOperationCount(eID)>count e=jT]i*cU  
        GetOperation eID, count, op QT= ,En  
        If op.Type="ShiftZ" Then 3)c K*8#  
            DeleteOperation eID,count ss
yd8LC#  
            count=count-1 ]F*a PV  
        End If ^0tf1pV2  
        count=count+1 K_+;"G  
    Wend i$^B-  
X*9N[#wu6  
    'Set new shift in PSf5p\<5  
    op.Type = "ShiftZ" -llx:  
    op.val1 = taq dbuJ~?D,  
    op.parent = parID q&Tn>B  
    AddOperation eID, op e
BC%2TF  
    Print "Set aqueous humor thickness = " & taq-0.55 cI%"Ynq"3  
zIm_7\e  
    '************************************************************************* I`'a'  
    'Radius and conic constant of anterior lens [&pW&>p3  
    '************************************************************************* g;!@DVF$  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) mhi90Jc  
    GetConic eID, entity, curv, conic ~'NpM#A  
\aVY>1`  
    SetConic eID, entity, 1/Rant, CCant w0j/\XN2s  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 4`U0">g
Y  
ig2+XR#%  
    '************************************************************************* ,s><kHJ  
    'Radius and conic constant of posterior lens M9s43XL(&  
    '************************************************************************* 4OOn,09  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) %t~SOkx  
    GetConic eID, entity, curv, conic (e8G (  
o`\.I&Ij  
    SetConic eID, entity, 1/Rpost, CCpost Vp]D  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost PwB g  
jH&_E'XMX  
    '************************************************************************* 6vgBqn[  
    'Lens thickness (Position of posterior lens surface) ^6aS]t  
    '************************************************************************* 5Z9~ &U  
a%T -Z.rd  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) x9)aBB  
UIf ZPf=  
    ' Delete any z-shift(s) 0Ws;|Y
g  
    count = 0 {+"g':><  
    While GetOperationCount(eID)>count hr[B^?6  
        GetOperation eID, count, op 7k]RO  
        If op.Type="ShiftZ" Then V@v1a@=W  
            DeleteOperation eID,count ,'C30A*p  
            count=count-1 ss`P QN  
        End If I%9bPQ  
        count=count+1 >sQ2@"y)s2  
    Wend `s`C{|wv  
3duG.iUlL  
    'Set new z-shift fimb]C I|x  
    op.Type = "ShiftZ" ^Ue0mC7m  
    op.val1 = tlens o#xgrMB  
    op.parent = parID wy{\/?~c  
    AddOperation eID, op w{3Q( =&  
    Print "Set lens thickness = " & tlens ,{?q^"  
':\fl.b  
    '************************************************************************* gwSN>oj &  
    'Lens index of refraction .!(,$'(@=  
    '************************************************************************* jow7t\wk  
    eID = FindMaterial( "Lens" ) I#U>5"%\a  
    GetModelMaterial eID, mat wfxOx$]zK  
gEv-
>pc  
    mat.Nd = nlens =2 &hQd   
    SetModelMaterial eID, mat g ?afX1Sg  
    Print "Set lens index of refraction = " & nlens }iilzE4oH#  
7L=T]W  
    '************************************************************************* P</s)"@  
    'Pupil diameter 8FzHNG  
    '************************************************************************* r8uqcKfU  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) {r={#mO;p  
%won=TG8  
    'Adjust pupil diameter (trimming volume inner hole) [J0*+C9P*  
6hkkNXqkf  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" vd}*_d  
UvkJ?Bu  
    ' Adjust pupil location to just in front of the lens j2|XDOf  
    parID = FindFullName( "Geometry.Arizona Eye" ) c 9rVgLqn!  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) h|bqyu  
    count = 0 cYGRy,'gH  
    While GetOperationCount(eID)>count FU%~9NKX  
        GetOperation eID, count, op N-[n\}'  
        If op.Type="ShiftZ" Then
'#v71,  
            DeleteOperation eID,count K7IyCcdB  
            count=count-1 Wk@ eV\H71  
        End If 6W5d7`A  
        count=count+1 U1l0Uke  
    Wend n0_B
(997*  
    op.Type = "ShiftZ" cDCJ]iDs  
    op.val1 = taq-0.01 ]}Pl%.  
    op.parent = parID $`|5/,M%QN  
    AddOperation eID, op z@zD .  
jm[}M  
    Print "Set pupil diameter = " & pupilDiam ?>sQF4 V"  
Aj,]n>{  
    'Update AZ Eye subassembly Description tG/aH%4S  
    eID = FindFullName( "Geometry.Arizona Eye" ) U\Ct/U&A?  
    GetEntity eID, entity Dy su{rL  
    entity.Description = "Accommodation = " & A & "D" TfJL+a0  
    SetEntity eID, entity (@ "=F6P  
l '/N3&5  
    Update tWm>j  
    Print "DONE!" 7Yuk  
     A8J8u,u9  
End Sub W9dYljnZ8i  
`)6>nPr7P  
如果屈光度是4，光瞳直径是4，则会输出如下数据： &.zj5*J  
@rF/]UJ  
Accommodation = 4 Diopters Y)|~:& tZ  
Pupil Diameter = 4 mm J{d(1gSZ  
Set aqueous humor thickness = 2.81 !2z!8kI  
Set anterior lens radius = 10.4 and conic constant = -2.375869 u+i(";\  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 !#?8BwnaZ  
Set lens thickness = 3.927 YgEM:'1f  
Set lens index of refraction = 1.42672 hyfR9~  
Set pupil diameter = 4 ~ FGe~  
DONE! E/ijvuO  
22>;vM."