[技术]Arizona眼睛模型 [复制链接]

简介 @7%.7LK  
yyjw?#\8  
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。 jQ|:I7y  
=DC3a3&%  
模型 s%O Y<B@V2  
|kc@L`7s  
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。 V9Hl1\j^  
"W5rx8a  
e}e6r3faz  
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. ?2ItTrlB  
W+\?~L.  
光源 T)~!mifX  
YQ7@D]#  
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。 0<Q*7aY  
!b63ik15O~  
BPewc9RxV  
r**f
,PDZ  
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。 !D;c,{Oz  
VX!hv`E  
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。 \7 Gz\=\LR  
bcn7,ht  
@vt$MiOi  
#x)8f3I  
视网膜的散射 = ^s$ <  
(v^Z BM_  
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。 MMd.0JuaO  
V&iS~V0.  
|IN[uQ  
j^nu|  
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。 ~b6GrY"vB  
%Kl(>{N  
e2wvc/gG6  
0>FE%  
脚本 'Wp@b678  
;MPKJS68@  
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： RG1\=J$:E  
o(fyd)t  

F>-}*o  
``4?a7!!  
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。 !iJipe5  
余下的脚本计算与屈光度有关的所有参数。 P)hi||[  
w & P&7  
分析 "V}qf3qU  
9!#EwPD$#  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 kceyuD$3G  
s[X B#)H4  
$r15gfne>  
脚本代码 ShGp^xVj  
g "*;nHI D  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. cmDT +$s  
QNg\4%  
Dim entity As T_ENTITY T5e^J"   
Dim op As T_OPERATION 1tGgDbJU  
Dim mat As T_MODELMATERIAL ix*muVBj.  
Dim A As Double ag;dc  
Dim pupilDiam As Double 8,*3zVk-  
Dim eID As Long 6bL~6-h%)  
Dim parID As Long (a#pvEY  
Dim count As Integer NwpS)6<-  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ti2  
Dim tlens As Double, nlens As Double =/}X$,@2  
Dim curv As Double, conic As Double HeozJ^u\?  
Dim ok As Long mb{q(WEPP  
H~Uq?
!=b  
Sub Main <5IQc[3]aP  
p6[ (81  
    '用户输入对话框 ri=+(NKo-  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 {y-`QS  
        TextBox 220,21,40,21,.TextBox1 'default: 0
h<NRE0-  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ,YB1 y)x  
        OKButton 40,91,90,21  zy>}L #  
        CancelButton 190,91,90,21 "% Y u wMY  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 u)~s4tP4  
        TextBox 220,49,40,21,.TextBox2 'default: 4 vYnftJK&  
    End Dialog WeVi]n  
    Dim dlg As UserDialog .NnGVxc5*  
rQj~[Y.c  
    ok = Dialog (dlg) BIfi:7I;Q  
vgThK9{m;  
    If ok=0 Then    'cancel button was pressed hSMV&Cs  
        Print "Execution cancelled." W[|[;{  
        End
DsQ/aG9c%  
    End If BX3lPv  
RL&lKHA  
    'Assign accommodation and pupil diameter & use defaults if field left empty OKPJuV`y6  
    If dlg.TextBox1 = "" Then %rcFT_  
        A = 0           'Default accommodation i!,HB|wQ  
    Else m =k%,J_  
        A = CDbl(dlg.TextBox1) r/PKrw sC  
    End If .@k*p>K  
"&-C$J5 Id  
    If dlg.TextBox2 = "" Then 7>,rvW:]  
        pupilDiam = 4   'Default pupil diameter TB#Nk5  
    Else PAoX$q  
        pupilDiam = CDbl(dlg.TextBox2) Ef,Cd[]b  
    End If K\^&+7&zVg  
[@2s&
Ct;  
    Print " " w+_Wc~f  
    Print "Accommodation = " & A & " Diopters" aU(tu2  
    Print "Pupil Diameter = " & pupilDiam & " mm" t?3BCm$Mi  
HcO5?{2  
    ' Calculate new parameters with accommodation f:vD`Fz1  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness yekRwo|  
Euu ,mleM  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #T"64%dX  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 3cThu43c  
q%S8\bt  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens I
?M@5u  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ML=z<u+  
d?7BxYa
a  
    tlens = 3.767 + 0.04*A                  'Lens thickness 5;Ia$lm=y  
sykFSPy`'  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {^m5#f 0"  
61:9(*4~!F  
    'Adjust parameters to account for accommodation x'i0KF   

MaErx\  
    '************************************************************************* P)1
EA;  
    'Aqueous thickness (Position of Lens) VDiOO  
    '************************************************************************* 2AK}D%jfc  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (\& 62B1  
    GetCustomElement eID, entity !Uy>eji}  
6~@5X}^<0  
    parID = FindFullName( "Geometry.Arizona Eye" ) Z4@y?fv7s  
7K:FeW'N  
    ' Delete any shift(s) in z \ V?I+Gc  
    count = 0 qZbHMTnT6  
    While GetOperationCount(eID)>count [YE?OQ7
#  
        GetOperation eID, count, op 5hz_P+Q  
        If op.Type="ShiftZ" Then u+z~  
            DeleteOperation eID,count jw4TLc7p  
            count=count-1 KPggDKS  
        End If Cuv|6t75'  
        count=count+1 tJm{I)G  
    Wend ^c'f<<z|7r  
26PD[af64O  
    'Set new shift in 3:AU:  
    op.Type = "ShiftZ" f4 O]`U  
    op.val1 = taq ccMd/  
    op.parent = parID h2;l1G,  
    AddOperation eID, op 6t$N78U  
    Print "Set aqueous humor thickness = " & taq-0.55 (&c,twa~  
3#mE( `|P  
    '************************************************************************* U8[Qw}T P  
    'Radius and conic constant of anterior lens tqhh<u;  
    '************************************************************************* `^%@b SE(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) R@$+t:}  
    GetConic eID, entity, curv, conic nx$bM(.  
^U{P3%uZ  
    SetConic eID, entity, 1/Rant, CCant t= *Jg/$  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant O{BW;Deo  
5Pqt_ZWy  
    '************************************************************************* +f
]u5p[  
    'Radius and conic constant of posterior lens TrQm]9@  
    '************************************************************************* y#e ?iE@  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) }VZM,.w  
    GetConic eID, entity, curv, conic 1tyNRoET  
Q@Dkl F  
    SetConic eID, entity, 1/Rpost, CCpost X+*<B(E  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost b"3uD`  
eA
&t%  
    '************************************************************************* i'iO H|s  
    'Lens thickness (Position of posterior lens surface) wt\m+!u`  
    '************************************************************************* z L8J`W  
Yx 3|G  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) xD^wTtT  
P eHW[\)  
    ' Delete any z-shift(s) MYu`c[$jZ  
    count = 0 {83C,C-  
    While GetOperationCount(eID)>count :mn(0 R~  
        GetOperation eID, count, op 1VGpq-4*j  
        If op.Type="ShiftZ" Then Bs@:rhDi  
            DeleteOperation eID,count +K&?)?/=  
            count=count-1 yZ|+VXO  
        End If wA1Ey:q  
        count=count+1 sX!3_'-  
    Wend X&.:H~xS+  
<OIUyZS  
    'Set new z-shift iel-<(~  
    op.Type = "ShiftZ" _hWuAJ9Qy  
    op.val1 = tlens 3l$E8?[Zwi  
    op.parent = parID ",QYDFFeF  
    AddOperation eID, op  d~sJ=)  
    Print "Set lens thickness = " & tlens X'xUwT|_+  
ovbEmb  
    '************************************************************************* dB
@F
I  
    'Lens index of refraction {x9j_/R  
    '************************************************************************* r(]98a]o~  
    eID = FindMaterial( "Lens" ) m|lM.]2_  
    GetModelMaterial eID, mat {wHvE4F2  
C_-%*]*,j  
    mat.Nd = nlens ,!r@9T  
    SetModelMaterial eID, mat {hM"TO7\  
    Print "Set lens index of refraction = " & nlens Y}S.37|+^  
'V1!&Q6  
    '************************************************************************* X8i[fk1.R  
    'Pupil diameter hRa\1Jt>a  
    '************************************************************************* =pyVn_dg  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) k?<
i*;7  
?P%|P  
    'Adjust pupil diameter (trimming volume inner hole) ]W+)ee|D  
El{r$-}  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >n1h^AW  
Shs')Zsbv  
    ' Adjust pupil location to just in front of the lens C0gfJ~M)  
    parID = FindFullName( "Geometry.Arizona Eye" ) \|blRm;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) )dqR<)  
    count = 0 ?vMK'"  
    While GetOperationCount(eID)>count "oHp.$+K  
        GetOperation eID, count, op /9P^{OZ;y  
        If op.Type="ShiftZ" Then )sRN
!~  
            DeleteOperation eID,count 'y< t/qo  
            count=count-1 7,f:Qi@g  
        End If U7jhV,gO4  
        count=count+1  ccRlql(  
    Wend $y8mK|3.3u  
    op.Type = "ShiftZ" JR])xPI`  
    op.val1 = taq-0.01 s%5Uj}  
    op.parent = parID ZTr:xX{R6  
    AddOperation eID, op 
hK Fk$A  
E2h(w_l  
    Print "Set pupil diameter = " & pupilDiam HJ
c<Gwm  
+I*k0"gj6  
    'Update AZ Eye subassembly Description tsck|;v  
    eID = FindFullName( "Geometry.Arizona Eye" ) I; ^xAd3G  
    GetEntity eID, entity =sxkrih  
    entity.Description = "Accommodation = " & A & "D" UP}feN  
    SetEntity eID, entity B^H4Q 4-  
:sU!PF[<  
    Update fDL3:%D
  
    Print "DONE!" 9*BoYFw92*  
     jMTRcj];(  
End Sub  o1 jk=  
b*cW<vX}~  
如果屈光度是4，光瞳直径是4，则会输出如下数据： )gr}<}X)B  
km9Gwg/zT  
Accommodation = 4 Diopters |Uc<;> l  
Pupil Diameter = 4 mm \)FeuLGL9  
Set aqueous humor thickness = 2.81 >s;oOo+5  
Set anterior lens radius = 10.4 and conic constant = -2.375869 4 U3C~J  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 rH[5~U  
Set lens thickness = 3.927 (irk$d %  
Set lens index of refraction = 1.42672 @m5O{[euj<  
Set pupil diameter = 4 S4;wa6  
DONE! i:C.8hmAE