[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 N~=A  
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。 *QE<zt  
Q^eJ4{Ya:  
模型 ,<ya@Fi{  
!)NidG  
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。 m8R=?U~!S  
Sn3:x5H,l  
N:+ taz-  
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. (N~$x  
Lx|',6S  
光源 'bW5Fr>W  
j kn^Z":  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 FT\?:wpKa  
y@vj;3:  
}4c/YP"a'E  
P-z`c\Rt  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。   &LQ%  
#I\Y=XCY  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 A{,n;;  
Z/ bB h  
&d$
~6'x*  
=_=*O
EgO]  
视网膜的散射 HD# r0)  
sy<iKCM\  
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。 QocQowz
 
4L:>4X[T  
8:g!w:$x  
FRyPeZR  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 z-u?s`k**  
we]>(|  
yqcM(,0]  
rFd@mO  
脚本 .)PqN s:  
Enj_tJs  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： xks?y.wA  
snMQ"ju  
6$e]i|e  
fD6GQ*  
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。 >A jCl  
余下的脚本计算与屈光度有关的所有参数。 :1<~}*B@{  
c4]u&tvjJ  
分析 RV!<?[  
?JqjYI{$  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Ph)|j&]  
O~'FR[J  
nm):SEkC  
脚本代码 Ml`vx  
k,_i#9X  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. W^R'@  
vfbe$4mH  
Dim entity As T_ENTITY +i)AS0?d  
Dim op As T_OPERATION {8m1dEC^@Q  
Dim mat As T_MODELMATERIAL 8eX8IR!K9  
Dim A As Double ?`. XK}  
Dim pupilDiam As Double /2w@K_Px6  
Dim eID As Long (T;9us0  
Dim parID As Long &>=#w"skb6  
Dim count As Integer xwLy|&  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double NV~vuC  
Dim tlens As Double, nlens As Double wgZrrq/W|  
Dim curv As Double, conic As Double Mo|yv[(K,  
Dim ok As Long )0|):g  
$c9=mjwH  
Sub Main l\aUresm  
FfXZ|o$;  
    '用户输入对话框 ak2dn]]D  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 csvOg[  
        TextBox 220,21,40,21,.TextBox1 'default: 0 UPO^V:.R
4  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 X%`KYo%  
        OKButton 40,91,90,21 ewQe/Fq  
        CancelButton 190,91,90,21 hho%~^bn(  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 d$Em\*C  
        TextBox 220,49,40,21,.TextBox2 'default: 4 1*c>I@I;  
    End Dialog H5p5S\g-)  
    Dim dlg As UserDialog DPeVKyjU  
'>]&rb09|  
    ok = Dialog (dlg) @\$Keg=>:  
bX&e_Pd  
    If ok=0 Then    'cancel button was pressed uN(b.5y  
        Print "Execution cancelled." EE9v
k*[@C  
        End 9fCO7AE0#  
    End If d5' )6  
?%;B`2 nDR  
    'Assign accommodation and pupil diameter & use defaults if field left empty <i7agEdZD  
    If dlg.TextBox1 = "" Then MA"#rOcP  
        A = 0           'Default accommodation bQV("~#  
    Else 4@/z  
        A = CDbl(dlg.TextBox1) "cQvd(kug  
    End If z+Z%H#9e  
,5:![  
    If dlg.TextBox2 = "" Then |Cq8%  
        pupilDiam = 4   'Default pupil diameter [yvt1:q  
    Else OaNc9c"  
        pupilDiam = CDbl(dlg.TextBox2) 3B -NYJa  
    End If /pU|ZA.z'2  
kU(kU
2u%9  
    Print " " 26}u4W$  
    Print "Accommodation = " & A & " Diopters" :@;6  
    Print "Pupil Diameter = " & pupilDiam & " mm" AtT"RG-6  
59~FpjJ  
    ' Calculate new parameters with accommodation 6~3jn+K$1  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {70Ou}*  
h-,?a_  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 'D
eW<Sa~  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens WN1Jm:5YV  
"Ac~2<V  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ZGzc"r(r:#  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens d["x= [f  
EqoASu  
    tlens = 3.767 + 0.04*A                  'Lens thickness 1oB$u!6P  
$)l2G;&  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction l_ZO^E~D_  
B#Qpd7E+*  
    'Adjust parameters to account for accommodation rI *!"PL  
C~{xL>I  
    '************************************************************************* *^ey]),f54  
    'Aqueous thickness (Position of Lens) %kJh6J  
    '************************************************************************* ['?^>jfr  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) tz"5+uuu  
    GetCustomElement eID, entity A%P 8c  
E`(5UF*>  
    parID = FindFullName( "Geometry.Arizona Eye" ) &+,:u*%  
T^d#hl.U  
    ' Delete any shift(s) in z G I&qwA  
    count = 0 CH55K[{<  
    While GetOperationCount(eID)>count i]LU4y%'  
        GetOperation eID, count, op n$IWoIdbGN  
        If op.Type="ShiftZ" Then gO9'q='5l  
            DeleteOperation eID,count ~37R0`C  
            count=count-1 avmcGyL  
        End If \)p4okpR  
        count=count+1 dZ.}j&ZH'  
    Wend j/~VP2R`  
N/(ofy  
    'Set new shift in g%+ql[(4  
    op.Type = "ShiftZ" @>+^W&  
    op.val1 = taq %N7gT*B:  
    op.parent = parID i0VhG:O;  
    AddOperation eID, op ZUv ZNf  
    Print "Set aqueous humor thickness = " & taq-0.55 gHp'3SnS  
/L)?> tg  
    '************************************************************************* B,r5kQI4  
    'Radius and conic constant of anterior lens CQj/e+eE4  
    '************************************************************************* M\9at\$  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 5z9JhU
 
    GetConic eID, entity, curv, conic =VCi8jDkP  
CM`x>J  
    SetConic eID, entity, 1/Rant, CCant 6.k^m&-A  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ,\BfmC_i  
Ewa[Y=+tx  
    '************************************************************************* .L~fFns/  
    'Radius and conic constant of posterior lens +dDJes!]  
    '************************************************************************* UENYJ*tnP  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Lr K9F^c  
    GetConic eID, entity, curv, conic x&QNP  
&uv>'S#%  
    SetConic eID, entity, 1/Rpost, CCpost Up_>y>x  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }*xC:A%aS  
V#p G; ,  
    '************************************************************************* I[tAT
[ <  
    'Lens thickness (Position of posterior lens surface) s4!|v`+$M  
    '************************************************************************* ,G916J*XA  
H4P\hOK7r  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Q,OkO?uY  
s4MNVT  
    ' Delete any z-shift(s) ju
8
',ZC  
    count = 0 sZ0g99eX  
    While GetOperationCount(eID)>count Wpiv1GZ%c8  
        GetOperation eID, count, op ?y+\v'3v  
        If op.Type="ShiftZ" Then U;x99Go:  
            DeleteOperation eID,count p*A^0DN'Fn  
            count=count-1
$I?=.:<+  
        End If k/$Ja;  
        count=count+1 Rh wt<  
    Wend 43UJ#rF  
:7HVBH  
    'Set new z-shift '?&B5C  
    op.Type = "ShiftZ" s98: *o3  
    op.val1 = tlens QT7w::ht  
    op.parent = parID .F{}~K]  
    AddOperation eID, op f]@[4<Ny  
    Print "Set lens thickness = " & tlens 'DaNR`9  
?7r
mwy\  
    '************************************************************************* &6|6J1c8  
    'Lens index of refraction T{5M1r  
    '************************************************************************* |[lxV&SD.  
    eID = FindMaterial( "Lens" ) yb@X*PW
/z  
    GetModelMaterial eID, mat mafAC73  
BDv|~NHs  
    mat.Nd = nlens bAA'=z<  
    SetModelMaterial eID, mat n?TO!5RZK  
    Print "Set lens index of refraction = " & nlens *so6]+)cU  
<8F->k1"3  
    '************************************************************************* KD[)O7hYC  
    'Pupil diameter Zq2H9^![y~  
    '************************************************************************* hr/xpQW  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $6Q2)^LJ  
E-*>f"<h  
    'Adjust pupil diameter (trimming volume inner hole) UgOGBj,&5W  
'ugR!o1  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" brpN>\  
&;uGIk>s  
    ' Adjust pupil location to just in front of the lens xc3Ov9`8%  
    parID = FindFullName( "Geometry.Arizona Eye" ) !VJT"Ds_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Zp% ""  
    count = 0 HbJadOK  
    While GetOperationCount(eID)>count (
+]Ig> t  
        GetOperation eID, count, op -7C=- \]  
        If op.Type="ShiftZ" Then JsAb q  
            DeleteOperation eID,count }[hDg6i  
            count=count-1 'xu7AKpU)  
        End If j,gM+4V^  
        count=count+1 A61-AwvF8-  
    Wend &L[8Mju6  
    op.Type = "ShiftZ" v]d?6g  
    op.val1 = taq-0.01 B<|q{D$N/  
    op.parent = parID IAt+S-q0  
    AddOperation eID, op j3V"d3)  
Hsux>+Q  
    Print "Set pupil diameter = " & pupilDiam ] BP^.N=  
5BGv^Qb_2  
    'Update AZ Eye subassembly Description HeAc(_=C  
    eID = FindFullName( "Geometry.Arizona Eye" ) .[eSKtbc)  
    GetEntity eID, entity s]V{}bY`  
    entity.Description = "Accommodation = " & A & "D" l#J>It\  
    SetEntity eID, entity 5u=U--  
O7L6Htya  
    Update #q^>qX y  
    Print "DONE!" QVA!z##  
     m-pIFL<^N  
End Sub g'l7Jr3  
w-q=.RSTn=  
如果屈光度是4，光瞳直径是4，则会输出如下数据： ' m#Ymp  
`zvT5=*-#  
Accommodation = 4 Diopters #f jX|b  
Pupil Diameter = 4 mm 2Xk1AS  
Set aqueous humor thickness = 2.81 .jG.90  
Set anterior lens radius = 10.4 and conic constant = -2.375869 f|HgLFx  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 =,}!Ns{k  
Set lens thickness = 3.927 b^|,9en  
Set lens index of refraction = 1.42672 mhHm#  
Set pupil diameter = 4 )I0g&e^Tzy  
DONE! T J"{nB  
B1AF4}~5