[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 v4?iOD  
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。 ]^"k8v/  
%XhfXd'  
模型 'p)Q68;&  
]/]ju$l9Z  
模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 jyW[m,#(go  
)tZ`K |  
%@&a7JOL  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. Y5A~E#zw  
l52a\
/  
光源 LR)& [{Kk  
#;9H@:N  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 "5DJu~  
n1(?|aJ#1  
\Z)1 ?fq  
vfvlB[  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 T!q_/[i~7  
ateUpGM QU  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 5$l9@0D.\  
p(3sgY1  
wV<
7pi  
L0Vgo<A  
视网膜的散射 >POO-8Q  
#*IVlchA"B  
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。 f%fa{  
D\L!F6taS  
tR
`S#rk  
RpQ*!a~O  
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。 1/j$I~B  
oC dGQ7G}  
H~+xB1  
o 5Zyh26  
脚本 #0y<a:}R  
SPy3~Db-o  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ?#[)C=p]z  
&/F_*=VE  
E1q%gi4Q%  
 .Oo/y0E^  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 @h-T:$  
余下的脚本计算与屈光度有关的所有参数。 w-
FnE}"l  
v+q<BYq  
分析 Y5TS>iEE]  
L4974E?S  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 2ChWe}f  
oj.lj!  
l:e9y$_)  
脚本代码 XCPb9<L  
)LFD6\z1pl  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. XI}I.M  
$4j^1U`~)K  
Dim entity As T_ENTITY g{ (@uzqG  
Dim op As T_OPERATION Zw=G@4xoU  
Dim mat As T_MODELMATERIAL 8=H\?4)()Y  
Dim A As Double h)B!LAr  
Dim pupilDiam As Double |'w^
n  
Dim eID As Long PZ]5Hf1"  
Dim parID As Long }brr ))  
Dim count As Integer K+ehr  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double zGs|DB  
Dim tlens As Double, nlens As Double FN{/.?w(  
Dim curv As Double, conic As Double *FPg
#a+  
Dim ok As Long _"f<Ol[!  
Baq ~}B<  
Sub Main oS!/|#mn  
Y?!/>q  
    '用户输入对话框 -uR{X G. D  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 u8uW9 <  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ZrcPgcF  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [t}):}~F|  
        OKButton 40,91,90,21 m!!;/e?yx  
        CancelButton 190,91,90,21 >\\5"Sf  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 q!
*MH/R  
        TextBox 220,49,40,21,.TextBox2 'default: 4 rt;gC[3\  
    End Dialog m^0A?jB
rR  
    Dim dlg As UserDialog !$E~\uT  
W:B}u\)C  
    ok = Dialog (dlg) ]L]T>~X`  
32KR--mn%  
    If ok=0 Then    'cancel button was pressed 3;D?|E]1  
        Print "Execution cancelled." oP-;y&AS  
        End c%yh(g  
    End If .HOY q  
R#fy60  
    'Assign accommodation and pupil diameter & use defaults if field left empty It\BbG=  
    If dlg.TextBox1 = "" Then a@k.$  
        A = 0           'Default accommodation ] zIfC>@R  
    Else Ys+N,:#R  
        A = CDbl(dlg.TextBox1) 3:O+GQ*  
    End If x 8M#t(hw  
P=pY8X:  
    If dlg.TextBox2 = "" Then ]-rczl|o  
        pupilDiam = 4   'Default pupil diameter {jUvKB_x  
    Else bXm:]?  
        pupilDiam = CDbl(dlg.TextBox2) ]TfeBX6ST  
    End If g1dmkX  
)+k[uokj  
    Print " " $l43>e{E  
    Print "Accommodation = " & A & " Diopters" "?+UI
 
    Print "Pupil Diameter = " & pupilDiam & " mm" {"}+V`O{  
9<~,n1b>x  
    ' Calculate new parameters with accommodation ZU^Q1}</5  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness wK ][qZ ]  
* T\>  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ndB@J*Im
u  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Lqq*Nr  
c}8 -/P=  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {'&8`d  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Tu'E{Hw  
mR6E]TuM  
    tlens = 3.767 + 0.04*A                  'Lens thickness y,1S&k  
8}J(c=4Gk  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Ta,u-!/I  
L&rO6  
    'Adjust parameters to account for accommodation zH'!fhcy  
BMe72  
    '************************************************************************* U0zW9jB  
    'Aqueous thickness (Position of Lens) "1\(ZKG8^Q  
    '************************************************************************* {M
A@A5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) @eA %(C  
    GetCustomElement eID, entity ]~ >@%v&  
@gY'YA8m  
    parID = FindFullName( "Geometry.Arizona Eye" ) O} (E(v  
H2s*s[T -  
    ' Delete any shift(s) in z ?F!W#  
    count = 0 y K=S!7p\  
    While GetOperationCount(eID)>count J~fuW?a]r  
        GetOperation eID, count, op +0SW ?#%  
        If op.Type="ShiftZ" Then i<0D Z_rub  
            DeleteOperation eID,count ho(5r5SNE  
            count=count-1 ?@yank|  
        End If ,WzG.3^m  
        count=count+1 ,q/tyGj  
    Wend _Eszr(zJ  
'"'D.,[W2  
    'Set new shift in m]Hb+Y=;h  
    op.Type = "ShiftZ" ,,zd.9n  
    op.val1 = taq / O|Td'Z  
    op.parent = parID Bi$ 0{V Z8  
    AddOperation eID, op q.U*X5  
    Print "Set aqueous humor thickness = " & taq-0.55 \IO$+Guh  
Q|6Ls$'$  
    '************************************************************************* {/th`#o4b  
    'Radius and conic constant of anterior lens dw'<"+zO  
    '************************************************************************* +.XZK3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) C+ZQB)gn  
    GetConic eID, entity, curv, conic 8  /5sv  
*vRNG 3D/  
    SetConic eID, entity, 1/Rant, CCant ^cfkP(Y3kx  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant .G7]&5s  
+R3\cRM  
    '************************************************************************* "u .)X3  
    'Radius and conic constant of posterior lens ~%D^Ga7  
    '************************************************************************* pE$|2v  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) uEc0/a :.  
    GetConic eID, entity, curv, conic xe"4u JO  
6~:W(E}  
    SetConic eID, entity, 1/Rpost, CCpost =$&7IQ?  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Dlqn~  
*#ob5TBq[  
    '************************************************************************* -lJx%9>  
    'Lens thickness (Position of posterior lens surface) $]Q*E4(kV9  
    '************************************************************************* BG(R=, 7  
UrD=|-r`  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) vLi/'|7  
&/J.0d-*``  
    ' Delete any z-shift(s) Y&K<{KA\4  
    count = 0
`@VM<av  
    While GetOperationCount(eID)>count 4*@G&v?n  
        GetOperation eID, count, op BXQ\A~P\  
        If op.Type="ShiftZ" Then Jdk3) \  
            DeleteOperation eID,count Bt|9%o06l  
            count=count-1 s9ju/+fv  
        End If Fi,e}j=2f  
        count=count+1 }1X11+/W  
    Wend s$SU vo1J  
'xLM>6[wz  
    'Set new z-shift _WRR 3  
    op.Type = "ShiftZ" N'lGA;}i  
    op.val1 = tlens INN/VDsJ  
    op.parent = parID ^P3g9'WK  
    AddOperation eID, op c%xED%X9  
    Print "Set lens thickness = " & tlens Q
2_WH)J 3  
=hZ&66  
    '************************************************************************* kuKnJWv  
    'Lens index of refraction !0!P.Q8>&  
    '************************************************************************* )V9Mcr*Ce6  
    eID = FindMaterial( "Lens" ) :Ul'(@  
    GetModelMaterial eID, mat kz$6}&uk  
SG(%d^x
`R  
    mat.Nd = nlens yi AG'[  
    SetModelMaterial eID, mat MHpL$g=5_  
    Print "Set lens index of refraction = " & nlens gLXvw]  
hB2s$QS  
    '************************************************************************* pAUfG^v  
    'Pupil diameter ~I/>i&|M1  
    '************************************************************************* (7rz:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 36x5q 1  
0,"n-5Im  
    'Adjust pupil diameter (trimming volume inner hole) mCC:}n"#  
QXIbFv  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" .Y^d
9.  
]|((b/L3  
    ' Adjust pupil location to just in front of the lens &dwI8@&  
    parID = FindFullName( "Geometry.Arizona Eye" ) vJ'yz#tl
9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ;QvvU[eb  
    count = 0 ?C#F?N0  
    While GetOperationCount(eID)>count N$ qNe'b  
        GetOperation eID, count, op }K#&5E  
        If op.Type="ShiftZ" Then ||
*&g2Y  
            DeleteOperation eID,count OGE#wG"S  
            count=count-1 )"i>R ~*  
        End If ki*79d"$  
        count=count+1 f/IRO33  
    Wend oC@"^>4  
    op.Type = "ShiftZ" u #=kb5}{  
    op.val1 = taq-0.01 0?&aV_:;X  
    op.parent = parID vBCZ/F[  
    AddOperation eID, op =JySY@
?9  
V5hlG =V  
    Print "Set pupil diameter = " & pupilDiam RB$ 8^#  
tx|"v|&e2  
    'Update AZ Eye subassembly Description k?|zIu  
    eID = FindFullName( "Geometry.Arizona Eye" ) x=)30y3*;  
    GetEntity eID, entity a dz;N;rIY  
    entity.Description = "Accommodation = " & A & "D" ?O.6r"  
    SetEntity eID, entity A Eyr_!G,  
79c9+  
    Update MSYLkQ}_b  
    Print "DONE!" I%zo>s6  
     ?:;hTY  
End Sub pYi=q
 
%unK8z  
如果屈光度是4，光瞳直径是4，则会输出如下数据： 0t:|l@zB  
gS(: c.  
Accommodation = 4 Diopters OL mBh3&  
Pupil Diameter = 4 mm .>gU 9A(Nk  
Set aqueous humor thickness = 2.81 f
B @pwmu  
Set anterior lens radius = 10.4 and conic constant = -2.375869 b$`4Nn|  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 45O6TqepN  
Set lens thickness = 3.927 ?GMeA}j  
Set lens index of refraction = 1.42672 tWX+\ |  
Set pupil diameter = 4 M;Mdz[Q  
DONE! )/N Xh'  
UNZVu~WnF