[技术]Arizona眼睛模型 [复制链接]

简介 >#u9W'@|  
QOT|6)Yb  
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。 jWpm"C  
\mp2LICQg  
模型 ;W~H|M  
A,PF#G(  
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。 HpCTQ\H  
C-
2{<$2k  
ZovF]jf k  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. lf`" (:./  
dbe\ YE  
光源 S
{d]0  
5MX7V4ist  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 s:/Wz39SY3  
Nflw
mMJ  
xR~9|H9a  
QgF2f/;!  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 &x"hM  
b)(si/]\  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 &s0_^5B0  
I+GP`=\  
5K#<VU*:  
r"4&.&6  
视网膜的散射 NG+%H1!$_  

"wi}/,)  
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。 9O4\DRe5c  
#Fkn-/nL  
'hNRIM1  
1sNZl&  
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。 )u?^w  
GeFu_7u!|  
$?*XPzZ  
werTwe2Q  
脚本 WF_24Mw  
?{]"UnyVE*  
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： /Z1>3=G by  
O*lMIWx  
VJbn/5+P  
iezY+`x4  
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。 H tx)MEZ  
余下的脚本计算与屈光度有关的所有参数。 ~P,@">}  
.22}=z  
分析 70F(`;  
Iy;bzHXs  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 dTVh{~/  
gg?O0W{  
4<btWbk5u*  
脚本代码 rCsH 0:l8P  
j"Z9}F@  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. cnL@j_mb  
$_+.D`vx`  
Dim entity As T_ENTITY  K)P].htw  
Dim op As T_OPERATION ,|^ lqY  
Dim mat As T_MODELMATERIAL q^Ui2  
Dim A As Double NOQSLT=  
Dim pupilDiam As Double S{S.H?{F  
Dim eID As Long k/m-jm_h  
Dim parID As Long S]<%^W'  
Dim count As Integer rPx:o}&<  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double |bX{MF  
Dim tlens As Double, nlens As Double ]
]6  
Dim curv As Double, conic As Double H|8i|vbi  
Dim ok As Long ^K?Mq1"Db  
"ZR^w5  
Sub Main w9,w?
%F  
OE(!^"5?[  
    '用户输入对话框 :^J'_  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 J%1 2Ey@6  
        TextBox 220,21,40,21,.TextBox1 'default: 0 X8~gLdv8  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 G|LcTV  
        OKButton 40,91,90,21 \w=*:Z  
        CancelButton 190,91,90,21 [J6q(}f  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 s-e<&*D[  
        TextBox 220,49,40,21,.TextBox2 'default: 4 +`+r\*C5  
    End Dialog QN8.FiiD  
    Dim dlg As UserDialog wh#x`Nc  
nD!5I@D  
    ok = Dialog (dlg) Lb0BmR%0  
*GC9o/  
    If ok=0 Then    'cancel button was pressed (R^Ca7F  
        Print "Execution cancelled." j9O"!9$vQ  
        End 4^{~MgQWK+  
    End If e)kVS}e?  
oF=UjA  
    'Assign accommodation and pupil diameter & use defaults if field left empty U,tWLX$@  
    If dlg.TextBox1 = "" Then X@^"@  
        A = 0           'Default accommodation }
^Ky)**  
    Else :eL ja*  
        A = CDbl(dlg.TextBox1) k(R&`  
    End If :=2l1Y[-G  
jbs)]fqC;  
    If dlg.TextBox2 = "" Then }x+s5a;!3/  
        pupilDiam = 4   'Default pupil diameter (nt=  
    Else \"=b8x  
        pupilDiam = CDbl(dlg.TextBox2) 0RkiD8U5  
    End If iNEE2BPp  
:'K%&e?7s  
    Print " " )jm u*D5N  
    Print "Accommodation = " & A & " Diopters" &/{x7;e  
    Print "Pupil Diameter = " & pupilDiam & " mm" hgI;^ia  
nI<Ab_EB  
    ' Calculate new parameters with accommodation mqKr+  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Bw*
6X`'Q  
=7 ${bp!  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens .>+jtp}  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens x L]Z3"p%  
vw
/X  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U Y')|2y 5  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens XZ1WY(  
p<AzpkU,A  
    tlens = 3.767 + 0.04*A                  'Lens thickness YfUUbV  
"bk'#?9  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }@NT#hD  
`'}c- Q  
    'Adjust parameters to account for accommodation |c3Yh,Sv  
[y1 x`WOk9  
    '************************************************************************* vGI?X#w3  
    'Aqueous thickness (Position of Lens) UWW_[dJr  
    '************************************************************************* YR
s32vVz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) <s(<ax30  
    GetCustomElement eID, entity B4ky%gF4  
8VLD yX2-  
    parID = FindFullName( "Geometry.Arizona Eye" ) [;8vO=Z  
N[8y+2SZ  
    ' Delete any shift(s) in z  4xnM7t\  
    count = 0 <o.?T*Q9  
    While GetOperationCount(eID)>count Sp^jC Xu  
        GetOperation eID, count, op d}_%xkC  
        If op.Type="ShiftZ" Then ?j-;;NNf  
            DeleteOperation eID,count G,JK$j>*l  
            count=count-1 J<=k [Q  
        End If _.G p}0a  
        count=count+1 IiRII)  
    Wend v %GcNjZk5  
k=r)kkO)  
    'Set new shift in n> O3p ~  
    op.Type = "ShiftZ" (N`x  
    op.val1 = taq 0F|DD8tHR  
    op.parent = parID d vTsbs/6  
    AddOperation eID, op n;,>Fv  
    Print "Set aqueous humor thickness = " & taq-0.55 {5N!udLDr5  
TWk1`1|  
    '************************************************************************* L2m~ GnP|?  
    'Radius and conic constant of anterior lens ye-R
  
    '************************************************************************* Fu6~8uDV{{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) yHt `kb2  
    GetConic eID, entity, curv, conic .*+KQA8  
X'KkIo :  
    SetConic eID, entity, 1/Rant, CCant ?f ]!~  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Bq)aA)gF  
5Sfz0  
    '************************************************************************* o6~9.~_e  
    'Radius and conic constant of posterior lens X__>r ?oJ  
    '************************************************************************* H&3i[D!p  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) -)2sR>`A%  
    GetConic eID, entity, curv, conic #}U*gVYe  
t:<dirw,o  
    SetConic eID, entity, 1/Rpost, CCpost H<bK9k)E  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost XP'7+/A  
9Di@r!Db  
    '************************************************************************* g4fe(.?c,  
    'Lens thickness (Position of posterior lens surface) iQnIk|8  
    '************************************************************************* XexslzI  
{Y#
$  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) nax(V  
G,6Zy-Y9  
    ' Delete any z-shift(s) "Ooc;xD3<  
    count = 0 e$+/;MRq  
    While GetOperationCount(eID)>count 3(/J(8  
        GetOperation eID, count, op !1s^TB>N  
        If op.Type="ShiftZ" Then XK7$Xbd  
            DeleteOperation eID,count Q-,,Kn  
            count=count-1 GI40Ztms  
        End If [~_()i=Y  
        count=count+1 ;`P}\Q{  
    Wend uh_2yw_  
2UGnRZ8:1Y  
    'Set new z-shift lImg+r T{  
    op.Type = "ShiftZ" 16N+  
    op.val1 = tlens nC>'kgRt  
    op.parent = parID K@UQ O  
    AddOperation eID, op C
YCG5)<9  
    Print "Set lens thickness = " & tlens @|cfFT W  
C0bOPn  
    '************************************************************************* }co*%F{1  
    'Lens index of refraction Zg#VZg1 2  
    '************************************************************************* 3.^Tm+ C  
    eID = FindMaterial( "Lens" ) ?U;KwS]%  
    GetModelMaterial eID, mat Qso"jYl<  
|`50Tf\J  
    mat.Nd = nlens JO `KNI  
    SetModelMaterial eID, mat 8^FAeV#  
    Print "Set lens index of refraction = " & nlens n6f  
^
KeJ=VT  
    '************************************************************************* QIg.r\>o  
    'Pupil diameter uK5&HdoM  
    '************************************************************************* z#!}4@_i3  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =Hs[peO*  
rL=_z^.P  
    'Adjust pupil diameter (trimming volume inner hole) *+wGXm  
wC~ra:/?:7  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :jc ?T  
b
im 82<F  
    ' Adjust pupil location to just in front of the lens 'l| e}eti>  
    parID = FindFullName( "Geometry.Arizona Eye" ) xc HG5bg|  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ."#M X!  
    count = 0 E =7m@"0  
    While GetOperationCount(eID)>count 8 FqhSzw  
        GetOperation eID, count, op b+g(=z+  
        If op.Type="ShiftZ" Then |Qe#[Q7  
            DeleteOperation eID,count =h<LlI^v  
            count=count-1 ?pAO?5Z:}  
        End If Z.]=u(=a  
        count=count+1 _FJ,, /~  
    Wend TL?(0]Hfe  
    op.Type = "ShiftZ" mx'!I7b(L/  
    op.val1 = taq-0.01 .1&~@e%=-  
    op.parent = parID ZM~kc|&  
    AddOperation eID, op <e s>FD  
y[W<vb+F  
    Print "Set pupil diameter = " & pupilDiam ?1G7=R  
;hsem,C h7  
    'Update AZ Eye subassembly Description ,>^6ztM  
    eID = FindFullName( "Geometry.Arizona Eye" ) u6,NQ^4  
    GetEntity eID, entity }c"1;C&{  
    entity.Description = "Accommodation = " & A & "D" (np %urx!  
    SetEntity eID, entity P9\!JH!  
@vC7j>*4B  
    Update Q^iE,_Zq  
    Print "DONE!" p..O;_U  
     J9kmIMq-C  
End Sub >brf7h  
J*lKXFq7  
如果屈光度是4，光瞳直径是4，则会输出如下数据： c:R`]4o  
n8!qz:z/  
Accommodation = 4 Diopters ):Vzv  
Pupil Diameter = 4 mm A@W/  
Set aqueous humor thickness = 2.81 *7ggw[~  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Gg\805L@  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 }nQni?  
Set lens thickness = 3.927 `o.DuvQ E  
Set lens index of refraction = 1.42672 JMUk=p<\  
Set pupil diameter = 4 A
V%?8-  
DONE! _msV3JBr