[技术]Arizona眼睛模型 [复制链接]

简介 f>s?4  
M[z)6.  
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。 2P]L9'N{Y  
@"Z7nJX  
模型 _{Sm k[  
/ }Rz=&  
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。 Cn>ADWpT&  
Ug:\  
dgDy5{_  
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. $''9K  
!r`,=
jK"  
光源 ifo7%XPcg  
50 A^bbid  
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。 l^d[EL+  
]r3Kg12
Mi  
O:{U^K:*  
X*Z8CM_  
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。 4O:W#bx  
~V/?H!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。 t6BHGX{o  
<" @zn  
kNT}dv]<  
}<z_Q_b+e  
视网膜的散射 `]LSbS  
l<Q>N|1#k%  
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。 '+ xu#R
  
DI`%zLDcY  
0 a~HiIh  
7~ztwL  
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。 (Y+N@d  
|v[Rp=?]  
bu&t'?zx!  
p#SY /KIw  
脚本 0aoHKeP  
5/gDK+%4D(  
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： *WE1;msr  
JbO ~n )%x  
_SACqamo5s  
(_r
EAEo  
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。 '!P"xBVAu  
余下的脚本计算与屈光度有关的所有参数。 &TG5rUUg  
pG^}Xf2a  
分析 cECi')  
n,~;x@=5  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 .D4bqL  
w[_x(Ojq;  
PY3ps2^K.  
脚本代码 NZN-^ >  
0t#g}  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. ES<{4<Kpx  
5efxEt>U  
Dim entity As T_ENTITY \V2,pi8'v  
Dim op As T_OPERATION &x-TW,#Ks  
Dim mat As T_MODELMATERIAL vG^#Sfgtw  
Dim A As Double pPVRsXy  
Dim pupilDiam As Double o{*ay$vA]  
Dim eID As Long )' xE
TA  
Dim parID As Long =2y8CgLj  
Dim count As Integer pium$4l2#  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double x'Pi5NRE  
Dim tlens As Double, nlens As Double kCUT ^  
Dim curv As Double, conic As Double 19(Dj&x  
Dim ok As Long u@p?  
hNXBVIL<&  
Sub Main NZu)j["  
%~j2 ('Y  
    '用户输入对话框 <DH*~tLp2  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 7%OKH<i\2<  
        TextBox 220,21,40,21,.TextBox1 'default: 0 *QM~O'WhD  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [oc~iDx%W  
        OKButton 40,91,90,21 4R>zPEo  
        CancelButton 190,91,90,21 Je4Z(kj 0  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 kW6%32  
        TextBox 220,49,40,21,.TextBox2 'default: 4 rZ_>`}O2  
    End Dialog oK+ WF  
    Dim dlg As UserDialog IfDx@?OB  
8_d-81Dd  
    ok = Dialog (dlg) nzX@:7g  
Uz%Z&K  
    If ok=0 Then    'cancel button was pressed ? 81X  
        Print "Execution cancelled." Q\{x)|{$  
        End [O-sVYB  
    End If d~ng6pA  
vMSW$Bx ;  
    'Assign accommodation and pupil diameter & use defaults if field left empty >+cVs:  
    If dlg.TextBox1 = "" Then %'L;FPxB  
        A = 0           'Default accommodation 'ul\Q`N3  
    Else l{P\No  
        A = CDbl(dlg.TextBox1) DE{h
5-g  
    End If 0MIUI<;j  

AB.(CS=i  
    If dlg.TextBox2 = "" Then v7trr W}  
        pupilDiam = 4   'Default pupil diameter <c,~aq#W'  
    Else d]0
a%Xh[  
        pupilDiam = CDbl(dlg.TextBox2) F.q|x|9j  
    End If Jd 3@cLCe-  
:ipoD%@  
    Print " " Q^eJ4{Ya:  
    Print "Accommodation = " & A & " Diopters" 3$M3Q]z  
    Print "Pupil Diameter = " & pupilDiam & " mm" 9w;?-  
TbE:||r?^  
    ' Calculate new parameters with accommodation (7$$;  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness /jD-\,:L}  
fW0$s`  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^E>CGGS4  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens d-!<C7O}  
]]iO- }  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {^q)^<#JT  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ar, 9U9  
0x)dnq\  
    tlens = 3.767 + 0.04*A                  'Lens thickness 2BB<mv K4  
!FG%2L4?,5  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction t Y1Et0  
Mpx/S<Z  
    'Adjust parameters to account for accommodation 'Am-vhpm  
x%BF{Sw  
    '************************************************************************* :iY$82wQ  
    'Aqueous thickness (Position of Lens) 6`nR5fh  
    '************************************************************************* >w'$1tc?+F  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) X,fu!  
    GetCustomElement eID, entity @YL}km&Fw  
KS>$`ax,
  
    parID = FindFullName( "Geometry.Arizona Eye" ) ahIE;Y\j'  
QocQowz
 
    ' Delete any shift(s) in z setLdEi  
    count = 0 ~a+NJ6e1  
    While GetOperationCount(eID)>count y8s=\`~PR  
        GetOperation eID, count, op LPE)  
        If op.Type="ShiftZ" Then FRyPeZR  
            DeleteOperation eID,count oNRG25  
            count=count-1 *v #/Y9}  
        End If ]W9B6G_  
        count=count+1 ]A:(L9  
    Wend Pern*x9$  
o'UHStk
 
    'Set new shift in `bP?o  
    op.Type = "ShiftZ" C|e+0aW  
    op.val1 = taq |XcH]7Ai"  
    op.parent = parID SPwPCI1?  
    AddOperation eID, op W,NL*($^  
    Print "Set aqueous humor thickness = " & taq-0.55 Gt^d;7x]  
QUP|FIpZ  
    '************************************************************************* %!W%#U0  
    'Radius and conic constant of anterior lens \|+/0USn  
    '*************************************************************************
M<oA<#IW  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) h
[U7!aM  
    GetConic eID, entity, curv, conic #( uj$[o  
' iQ9hQjD  
    SetConic eID, entity, 1/Rant, CCant nm):SEkC  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9O >z4o  
sJ6a7A8)  
    '************************************************************************* k,_i#9X  
    'Radius and conic constant of posterior lens GXeAe}T  
    '************************************************************************* 8R/ *6S=&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +i)AS0?d  
    GetConic eID, entity, curv, conic {8m1dEC^@Q  
8eX8IR!K9  
    SetConic eID, entity, 1/Rpost, CCpost e[4V%h  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %cj58zO|y  
QMb^&?;s  
    '************************************************************************* nEVbfNo0  
    'Lens thickness (Position of posterior lens surface) 5; f\0<-  
    '************************************************************************* )F E8D  
[$:@X V(  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) H-a^BZ&iU  
Xiju"Cup"  
    ' Delete any z-shift(s) SsRVd^=;x  
    count = 0 ay[ZsQC  
    While GetOperationCount(eID)>count PW^ 8;[\QP  
        GetOperation eID, count, op 5B|,S1b  
        If op.Type="ShiftZ" Then EI
K*49b2  
            DeleteOperation eID,count xMsGs  
            count=count-1 G+C}<S}  
        End If Q?]w{f(  
        count=count+1 $3:X+X  
    Wend Bm<^rhJ9  
|8'B/ p=  
    'Set new z-shift ~
,Mr0  
    op.Type = "ShiftZ" 8r^j P.V  
    op.val1 = tlens f!!P  
    op.parent = parID |D(&w+(  
    AddOperation eID, op "OJr*B  
    Print "Set lens thickness = " & tlens `vX4!@Tw  
cuMc*i$w!  
    '************************************************************************* 4tnjXP8  
    'Lens index of refraction :p$EiR  
    '************************************************************************* WVkG2  
    eID = FindMaterial( "Lens" ) &%:*\_2
s  
    GetModelMaterial eID, mat -fQX4'3R  
3.~h6r5-  
    mat.Nd = nlens x Ty7lfSe  
    SetModelMaterial eID, mat N1s.3`  
    Print "Set lens index of refraction = " & nlens #'iPDRYy  
c.-cpFk^L&  
    '************************************************************************* `$f2eB&   
    'Pupil diameter iP,v=pS6  
    '************************************************************************* 4JSZ0:O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &/DOO ^  
ooDdV >  
    'Adjust pupil diameter (trimming volume inner hole) 8.-S$^hj~6  
&58 {  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" rFO_fIJno  
;,v.(Z ic  
    ' Adjust pupil location to just in front of the lens QSv^l-<  
    parID = FindFullName( "Geometry.Arizona Eye" ) H}a)^90_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *@~`d*d  
    count = 0 p4y6R4kyT  
    While GetOperationCount(eID)>count >F~ITk5`Oo  
        GetOperation eID, count, op sU0Stg8&b  
        If op.Type="ShiftZ" Then Vp\80D&
  
            DeleteOperation eID,count 3Cd<p[%3#,  
            count=count-1 q>P[nz%  
        End If ^+URv  
        count=count+1 unJiE!  
    Wend =!YP$hfY  
    op.Type = "ShiftZ" bu_/R~&3{  
    op.val1 = taq-0.01 nrF!;:x  
    op.parent = parID )FV6

,  
    AddOperation eID, op Dl&PL  
[~!.a\[RW  
    Print "Set pupil diameter = " & pupilDiam 7^&lbzVbm(  
S;>4i!Mb ^  
    'Update AZ Eye subassembly Description @OY1`EuO  
    eID = FindFullName( "Geometry.Arizona Eye" ) ['?^>jfr  
    GetEntity eID, entity (;C$gnr.C  
    entity.Description = "Accommodation = " & A & "D" gu^_iU  
    SetEntity eID, entity |$Qp0vOA}  
f!mE1,eBEe  
    Update U{HyxZ|q<  
    Print "DONE!" :&qC<UD  
     5"$e=y/  
End Sub $]nVr(OZ_  
QN3qF|))  
如果屈光度是4，光瞳直径是4，则会输出如下数据： bG"6pU  
Tw}@+-  
Accommodation = 4 Diopters :a=ro2NH  
Pupil Diameter = 4 mm ?<Z)*CF)  
Set aqueous humor thickness = 2.81 vwm|I7/w  
Set anterior lens radius = 10.4 and conic constant = -2.375869 5Ws5X_?d  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 8I<_w4fC  
Set lens thickness = 3.927 =jsx(3V  
Set lens index of refraction = 1.42672 Av@&hD\  
Set pupil diameter = 4 t
N[St  
DONE! yB 1I53E