[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 O0:q;<>z  
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。 QWU-m{@~&  
'fW-Y!k%  
模型 ^f@=:eWI  
+ai< q>+  
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。 tX[WH\(xI  
d_CT$  
H*6W q  
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. {)Xy%QV  
r|Z{-*`  
光源 NlXimq  
cb bFw  
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。 _dg\\c  
,//S`j$S  
0`H# '/  
.]Z"C&"N]  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 Zd&S@Z  
kT=8e;K  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 {+Jv+J9  
,,T
nIouy  
*ui</+  
!9x}  
视网膜的散射 xD$\,{  
5-M-X#(  
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。 =c7;r]Ol  
'q.!|G2U  
t<qiGDJ<d  
2rMpgV5  
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。 ,?3G;-  
T
C"<g  
WhDJ7{D  
%)wjR/o  
脚本 45oR=Atn  
<GsuZ  
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： PW4q~rc=:  
;d?R:Uw8  

_4f;<FL  
hOeRd#AQK  
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。 F!do~Z  
余下的脚本计算与屈光度有关的所有参数。 "5 A!jq  
f!"w5qC^  
分析 7o4\oRGV  
fR|A(u#9  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Ep}s}Stlr}  
KTv$  
ElXFeJ%[G  
脚本代码 liSmjsk  
`{Ul!  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. \Cj B1]I  
\DzGQ{`~
m  
Dim entity As T_ENTITY <QvOs@i*  
Dim op As T_OPERATION P*o9a  
Dim mat As T_MODELMATERIAL <}
LC~B!  
Dim A As Double j#6.Gq  
Dim pupilDiam As Double 0aAoV0fMDz  
Dim eID As Long =T_g}
pu  
Dim parID As Long ME dWLFf  
Dim count As Integer Ls%MGs9PI  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #
b`ke/P  
Dim tlens As Double, nlens As Double u4j5w  
Dim curv As Double, conic As Double b]y2+A.
n  
Dim ok As Long ~m |BC*)  
M`>E|"<  
Sub Main % `3jL7|  
"]dI1 g_  
    '用户输入对话框 ]{iQ21`a-  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 f<H2-
(m  
        TextBox 220,21,40,21,.TextBox1 'default: 0 VE24ToI?W"  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 MJvp6n  
        OKButton 40,91,90,21 #F#%`Rv1  
        CancelButton 190,91,90,21 L$-T,Kze  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 3u;oQ5<(v  
        TextBox 220,49,40,21,.TextBox2 'default: 4 >/|*DI-HJ  
    End Dialog 6 r"<jh#  
    Dim dlg As UserDialog 3Y &d=  
+0~YP*I`/  
    ok = Dialog (dlg) :>*7=q=  
JO;Uus{?  
    If ok=0 Then    'cancel button was pressed /NlGFO*Z  
        Print "Execution cancelled." /\Ef%@  
        End G9lUxmS<  
    End If 99S^f:t  
:0ep(<|;  
    'Assign accommodation and pupil diameter & use defaults if field left empty  eIlva?  
    If dlg.TextBox1 = "" Then <!+Az,-  
        A = 0           'Default accommodation G#CXs:1pd+  
    Else k\IbIv7?i  
        A = CDbl(dlg.TextBox1) s>en  
    End If RpK@?[4s  
R2;  
    If dlg.TextBox2 = "" Then O}P`P'Y|'  
        pupilDiam = 4   'Default pupil diameter hc1N~$3!G  
    Else 8QK&
_n*  
        pupilDiam = CDbl(dlg.TextBox2) ;,TFr}p`
 
    End If "zc l|@  
aYeR{Y]  
    Print " " GmG5[?)  
    Print "Accommodation = " & A & " Diopters" g\U-VZ6;p  
    Print "Pupil Diameter = " & pupilDiam & " mm" G6/m#  
iwq!w6+  
    ' Calculate new parameters with accommodation C}X\|J  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness .N3mb6#[R  
m[$_7a5  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens (mOtU8e  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens u!s2BC0}N  
[Zrr)8A  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;`Z{7'^U  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens %C0Dw\A*:  
~[ F`"  
    tlens = 3.767 + 0.04*A                  'Lens thickness i?/qY&~  
=v\.h=~~  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction K'xV;r7Nt  
O2+6st  
    'Adjust parameters to account for accommodation lFkR=!?=  
5N]
"~w*  
    '************************************************************************* FsPw1A$y  
    'Aqueous thickness (Position of Lens) <$YlH@;)`a  
    '************************************************************************* i@q&5;%%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) wq{hF<  
    GetCustomElement eID, entity 6LZCgdS{  
}qUX=s GG  
    parID = FindFullName( "Geometry.Arizona Eye" ) {_}I!`opr$  
r^ XVB`v  
    ' Delete any shift(s) in z gr{ DWCK  
    count = 0 |:o4w  
    While GetOperationCount(eID)>count _GPe<H  
        GetOperation eID, count, op 3R/bz0 V>  
        If op.Type="ShiftZ" Then >_TZ'FT  
            DeleteOperation eID,count ,+VGSd  
            count=count-1 0_/[k*Re  
        End If >~f]_puT  
        count=count+1 TvM~y\s  
    Wend "tZe>>I  
m'U0'}Ld};  
    'Set new shift in K}y f>'O  
    op.Type = "ShiftZ" AX INThJ  
    op.val1 = taq cK@wsA^4  
    op.parent = parID 54,er$$V  
    AddOperation eID, op xk5]^yDp  
    Print "Set aqueous humor thickness = " & taq-0.55 h;Kx!5)y  
}vuARZ>  
    '************************************************************************* Y2TtY;  
    'Radius and conic constant of anterior lens :0/7,i  
    '************************************************************************* sA~]$A;DM!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) b>W%t  
    GetConic eID, entity, curv, conic sKWfXCd  
i%/+5gq  
    SetConic eID, entity, 1/Rant, CCant /FII07V  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant FmW(CGs  
[^)g%|W  
    '*************************************************************************
(:_$5&i7  
    'Radius and conic constant of posterior lens 1 zZlC#V  
    '************************************************************************* [0of1eCSl  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) b>|6t~}M  
    GetConic eID, entity, curv, conic #cJ@uqR  
DXo|.!P=3  
    SetConic eID, entity, 1/Rpost, CCpost K9[UB  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost gi8FHSU|G  
M:8R-c#![  
    '************************************************************************* !if   
    'Lens thickness (Position of posterior lens surface) c$,P ~Ws'  
    '************************************************************************* | Iib|HQ)  
\zY!qpX<  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZNoDFf*h  
Q8NX)R  
    ' Delete any z-shift(s) XX@ZQcN  
    count = 0 '%qr.T %  
    While GetOperationCount(eID)>count uH]OEz\H'  
        GetOperation eID, count, op KXy6Eno  
        If op.Type="ShiftZ" Then *hx  
            DeleteOperation eID,count d$RIS+V  
            count=count-1 NUZl`fu1Z4  
        End If p?!/+  
        count=count+1 =(Mch~  
    Wend 3Ul*QN{6  
=&]L00u.  
    'Set new z-shift BLttb  
    op.Type = "ShiftZ" Ey2^?  
    op.val1 = tlens 8Wx=p#_  
    op.parent = parID  DrR@n~  
    AddOperation eID, op ,2q-D&)\Z  
    Print "Set lens thickness = " & tlens L#J1b!D&<6  
>
j/w@Fj  
    '************************************************************************* ![1rzQvGDb  
    'Lens index of refraction *T/']t  
    '************************************************************************* vgPCQO([  
    eID = FindMaterial( "Lens" ) $]d^-{|  
    GetModelMaterial eID, mat qna8|3
eP  
NOva'qk  
    mat.Nd = nlens "x-j~u?  
    SetModelMaterial eID, mat +rd+0 `}C  
    Print "Set lens index of refraction = " & nlens 29KiuP  
;`&kZi60Hz  
    '************************************************************************* ? k/`  
    'Pupil diameter <YY14p  
    '************************************************************************* {mg2pfhB!  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) b;n[mk  
! mHO$bQ"  
    'Adjust pupil diameter (trimming volume inner hole) ]esC[r]PJ  
}tz7b#  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" C_Dn{  
~Y;*u]^  
    ' Adjust pupil location to just in front of the lens icgfB-1|i  
    parID = FindFullName( "Geometry.Arizona Eye" ) uFE)17E  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) se)TzI^]b@  
    count = 0 UN
Yqft4  
    While GetOperationCount(eID)>count d6O[ @CyP  
        GetOperation eID, count, op _/|\aqF.  
        If op.Type="ShiftZ" Then @]j1:PN-  
            DeleteOperation eID,count {FkF  
            count=count-1 p{_" bB  
        End If ;pAK_>
 
        count=count+1 J5
q
ZFD  
    Wend hb$Ce'}N  
    op.Type = "ShiftZ" jp,4h4C^)  
    op.val1 = taq-0.01 7! Nsm  
    op.parent = parID TbU#96"~.  
    AddOperation eID, op A^g(k5M*  
6m93puY
`7  
    Print "Set pupil diameter = " & pupilDiam F8=+j_UGI  
LVGe]lD  
    'Update AZ Eye subassembly Description s;e\ pt  
    eID = FindFullName( "Geometry.Arizona Eye" ) @{Q4^'K"  
    GetEntity eID, entity /: "1Z]@  
    entity.Description = "Accommodation = " & A & "D" f|5co>Hk  
    SetEntity eID, entity qX%_uOw:%  
)
7F/O3Tq  
    Update .*oU]N%K=  
    Print "DONE!" ]^E?;1$f?  
     ye&;(30Oq  
End Sub kVgTGC"L=  
CJY$G}rk  
如果屈光度是4，光瞳直径是4，则会输出如下数据： P:c w|Q  
^q5#ihM  
Accommodation = 4 Diopters oR'm2d^  
Pupil Diameter = 4 mm uRvP hkqm  
Set aqueous humor thickness = 2.81 u9e@a9c  
Set anterior lens radius = 10.4 and conic constant = -2.375869 [0!(xp^  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 %b$>qW\*&  
Set lens thickness = 3.927 q V=!ORuj  
Set lens index of refraction = 1.42672 04ui`-c(  
Set pupil diameter = 4 Lbgi7|&  
DONE! y[;>#j$  
zhQJy?>'m