[技术]Arizona眼睛模型 [复制链接]

简介 }s)Z:6;(,q  
VqbiZOZ@  
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。 S;t~"87v*  
>^Y9p~  
模型 >)N#n`  
qnA:[H;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。 ;m5M:Z"  
i
F%q
6R  
]!A;-m  
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. ^M80 F7  
hCDI;'ls  
光源 VLO>{"{'  
8odVdivh  
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。 nuCK7X  
\;?\@vo<  
<pE G8_{}  
G` 8j ^H,  
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。 t]` 2f3UO  
0)/214^&  
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。 )F~_KD)7jJ  
gRFC n6Q  
H 0h  
hD,-!R  
视网膜的散射 $?s^HKF~  
[qXpi'q[  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ?UxY4m%R;  
T9$U./69-L  
9F-k:hD |  
h49Q2`  
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。 $e_ps~{7$  
\8$`:3,@  
)
s8r(.W  
H|!s.  
脚本 [yyV`&  
vr vzV  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： yjr@v!o  
a(7ryl~c=  
NV gLq@F  
};j&)M  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 Z\L@5.*ydE  
余下的脚本计算与屈光度有关的所有参数。 Lg?'1dg  
`u}x:f !  
分析 k|_2aQ02  
Om^/tp\  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 7X|r';"?i  
j{^
(TE  
d"78:+  
脚本代码 HDEG/k/~m  
9,W-KM  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. K$.zO4  
md`ToU  
Dim entity As T_ENTITY :qbG%_PJ  
Dim op As T_OPERATION yRYWx` G  
Dim mat As T_MODELMATERIAL X2`>@GR/>  
Dim A As Double P&GZe/6Y  
Dim pupilDiam As Double -b$OHFL  
Dim eID As Long caP  
Dim parID As Long |FFC8R%@]u  
Dim count As Integer d.AjH9 jg  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double (*ng$zZ$  
Dim tlens As Double, nlens As Double
E1C_d'  
Dim curv As Double, conic As Double LC{hoq\  
Dim ok As Long sV<4^n7  
Fjzk;o  
Sub Main @r?`:&m0  
/)1-
^ju  
    '用户输入对话框 5avO48;Vc  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 4I*Mc%dD  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Lm|X5RVq  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 qJA.+q.e$e  
        OKButton 40,91,90,21 sJoi fl 7  
        CancelButton 190,91,90,21 !cb#fl  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 50&F#v%YB  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ~N9-an  
    End Dialog 6\;1<Sw*  
    Dim dlg As UserDialog YZl%JX  
^rwSbM$  
    ok = Dialog (dlg) _w;+Jh  
dLf8w>i`T  
    If ok=0 Then    'cancel button was pressed fO
^6q1a  
        Print "Execution cancelled." Bx-,"Z \  
        End Aa>gN  
    End If MPbPq3an  
'I]"=O,  
    'Assign accommodation and pupil diameter & use defaults if field left empty 3.X0!M;x  
    If dlg.TextBox1 = "" Then =on!&M  
        A = 0           'Default accommodation Td*Oljj._U  
    Else sK0VT"7K  
        A = CDbl(dlg.TextBox1) ?MM3LA! <  
    End If Fz&ilB  
Qiw4'xQm  
    If dlg.TextBox2 = "" Then v4_OUA>z,  
        pupilDiam = 4   'Default pupil diameter
yrAzD=  
    Else "5:f{GfO#v  
        pupilDiam = CDbl(dlg.TextBox2) k{jw%a<Sc  
    End If 4QAIQQS  
V1)P=?%(US  
    Print " " /dt!J `:  
    Print "Accommodation = " & A & " Diopters" VtiqAh}4  
    Print "Pupil Diameter = " & pupilDiam & " mm" %J7mZB9  
b0Ov+ )7#  
    ' Calculate new parameters with accommodation !`[I>:Ex  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ]A$^ l,  
Lzx$"R-  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens I<./(X[H:#  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens +esNwz_   
5w)^~#'  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ~e77w\Q0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Nu/Qa:H_{  
07Q[L'}y@  
    tlens = 3.767 + 0.04*A                  'Lens thickness N5s
|a5  
IXvz&4VD  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction gkML .u  
ef}E.Bl  
    'Adjust parameters to account for accommodation 5A$az03y$\  
?lDcaI>+n  
    '************************************************************************* *rcuhw"^b#  
    'Aqueous thickness (Position of Lens) 8@yc}~8 *  
    '************************************************************************* >xV<nL
f/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) /~l/_Jct@G  
    GetCustomElement eID, entity 8o7]XZE=)  
e=o{Zo?H=  
    parID = FindFullName( "Geometry.Arizona Eye" ) >'-w%H/  
>Ug?O~-  
    ' Delete any shift(s) in z j%Z{.>mJ  
    count = 0 _8b]o~[Z+  
    While GetOperationCount(eID)>count XDdcq]*|  
        GetOperation eID, count, op s i"`  
        If op.Type="ShiftZ" Then 'CX.qxF1;p  
            DeleteOperation eID,count (Ef2 w['  
            count=count-1 w$lfR,  
        End If Uk*;C  
        count=count+1 m/hi~.D9  
    Wend 8jjk?PUD8  
KtUGI.X  
    'Set new shift in j&[.2PW\  
    op.Type = "ShiftZ" 
q"+ q  
    op.val1 = taq HM@}!6/s  
    op.parent = parID 1%hM8:)i_  
    AddOperation eID, op ra%R:xX  
    Print "Set aqueous humor thickness = " & taq-0.55 c
o^P7+j  
?$J7%I@  
    '************************************************************************* !*?(Q6  
    'Radius and conic constant of anterior lens d@6:|auO  
    '************************************************************************* 2&gVZz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 9U7Mu;4  
    GetConic eID, entity, curv, conic 85%Pq:E  
&=z1$ih>2\  
    SetConic eID, entity, 1/Rant, CCant _7=pw5[  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant yxCMl.  
fsrg2:kQ  
    '************************************************************************* loeLj4""  
    'Radius and conic constant of posterior lens t?9;cS4  
    '************************************************************************* BK(pJNBh  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) A&|Wvb=  
    GetConic eID, entity, curv, conic hnsa)@  
=nvAOvP{?  
    SetConic eID, entity, 1/Rpost, CCpost @cu}3>  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost tB,.  
!$p2z_n$@.  
    '************************************************************************* of+phMev  
    'Lens thickness (Position of posterior lens surface) u+z .J4w  
    '************************************************************************* kJurUDo  
XWUvP  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) v?Yd
LR  
cXb @H#  
    ' Delete any z-shift(s) }_a+X  
    count = 0 hy$M
V3LP  
    While GetOperationCount(eID)>count c#{Ywh  
        GetOperation eID, count, op {+C%D'  
        If op.Type="ShiftZ" Then `R=a@DQ  
            DeleteOperation eID,count 23}BW_m  
            count=count-1 28T\@zi  
        End If YQ8j  
        count=count+1 ~T>jBYI0  
    Wend nr<WO~Xw~  
W(uP`M%][0  
    'Set new z-shift VY+(,\)U  
    op.Type = "ShiftZ" x{NNx:T1  
    op.val1 = tlens ><;l:RGK|  
    op.parent = parID A*7Io4e!  
    AddOperation eID, op W{fULl  
    Print "Set lens thickness = " & tlens ).0V%}>  
="3a%\  
    '************************************************************************* vQ-i
xh  
    'Lens index of refraction %_B:EMPd  
    '************************************************************************* _`bS[%CJ  
    eID = FindMaterial( "Lens" ) {BFT  
    GetModelMaterial eID, mat JqI6k6~Q^  
IF&g.
R  
    mat.Nd = nlens Sni&?tcY  
    SetModelMaterial eID, mat >]Mq)V9  
    Print "Set lens index of refraction = " & nlens ; g Z%U  
[;(]Jy  
    '************************************************************************* T&9`?QD  
    'Pupil diameter ps"/}u l  
    '************************************************************************* O"
%Hprx  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 8_xnWMOe  
{PN:bb  
    'Adjust pupil diameter (trimming volume inner hole) Dk)@>l:gI,  
5Y(r\Dd  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" !Oeq G  
)8pcf`h{  
    ' Adjust pupil location to just in front of the lens b%Wd<N2  
    parID = FindFullName( "Geometry.Arizona Eye" ) JQ*D  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) tO?21?AD D  
    count = 0 reJ"r<2  
    While GetOperationCount(eID)>count 7<h.KZPc  
        GetOperation eID, count, op kx|me~I  
        If op.Type="ShiftZ" Then yB-.sGu  
            DeleteOperation eID,count 84iJ[F
q{  
            count=count-1 [X;>*-  
        End If X3P&"}a  
        count=count+1 R<Z^L~)  
    Wend |if'_x1V  
    op.Type = "ShiftZ" jmkRP"ZnA  
    op.val1 = taq-0.01 3H1Pp*PH  
    op.parent = parID y7CWBTH0>  
    AddOperation eID, op 8ou e-:/a  
CXBzX:T?#  
    Print "Set pupil diameter = " & pupilDiam OZ
G0AX+=#  
e&d3SQ%  
    'Update AZ Eye subassembly Description Kn']n91m  
    eID = FindFullName( "Geometry.Arizona Eye" ) pp(H PKs=}  
    GetEntity eID, entity 2*+3RrJ  
    entity.Description = "Accommodation = " & A & "D" 6H0W`S0a  
    SetEntity eID, entity Gu2_dT  
7nm}fT z7  
    Update O4T'o.  
    Print "DONE!" mRCHrw?WG  
     d{W}p~UbH  
End Sub [u[ U_g*  
GOGt?iw*<  
如果屈光度是4，光瞳直径是4，则会输出如下数据： L*P_vCC  
W3^.5I  
Accommodation = 4 Diopters _Aa[?2 O  
Pupil Diameter = 4 mm ,NDh@VYe  
Set aqueous humor thickness = 2.81 |Z d]=tue  
Set anterior lens radius = 10.4 and conic constant = -2.375869 G OpjRA@  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 fVYiwE=F  
Set lens thickness = 3.927 d5Qd'  
Set lens index of refraction = 1.42672 T0r<O_ubOA  
Set pupil diameter = 4 kg:l:C)Tq  
DONE! UIn^_}jF`