[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ?+}_1x`  
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。 :E )>\&  
RdRp.pb8  
模型 *wB1,U{  
%/#NK1&M  
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。 p4 ^yVa  
ExL0?FemWV  
Cd}<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. 'kO!^6=4M  
lchPpm9  
光源 IKilr'  
P:MT*ra*,  
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。 ={@6{-tl  
V{3x!+q  
|imM#wF  
KF!Yf\  
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。 ,M ^<CJ  
PP33i@G  
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。 R|87%&6']
 
jkF
^-Up.  
:emiQ  
o9yJf#-En  
视网膜的散射 naz
Z*lC  
5IjGm  
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。 3eAX.z`D  
0rs"o-s<  
l L@XM2"  
gu.}M:u  
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。 qHlQ+:n  
9w"4K.  

< !C)x  
m'=Crei  
脚本 nV/G8SeI  
`%"\@<  
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： j@3Q;F0ba  
X[BIA+6  
TpwkD_fg  
oDAXiY$u  
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。 FxWSV|Z  
余下的脚本计算与屈光度有关的所有参数。 3<f}nfB%r?  
2*l/3VW  
分析 h_3E)jc  
M; tqp8  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 3J|F?M"N7  
Q6!zZ))~  
_FU_Ubkr  
脚本代码 SBk4_J/_  
Z4w!p?Wqa  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. ,pQZ@I\z  
$2M$?4S/T  
Dim entity As T_ENTITY NgGp  
Dim op As T_OPERATION BLf>_bUk  
Dim mat As T_MODELMATERIAL '9Xu p  
Dim A As Double Hc$O{]sq  
Dim pupilDiam As Double -4IE]'##  
Dim eID As Long rCbDu&k]  
Dim parID As Long jTtu0Q|  
Dim count As Integer ;LPfXpR  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double b)5uf'?-  
Dim tlens As Double, nlens As Double 0#s"e}@v  
Dim curv As Double, conic As Double aU "8{  
Dim ok As Long IT7
wT+  
yT"Eq"7/Y#  
Sub Main Val|n*%  
/}fHt^2H  
    '用户输入对话框 (!7sE9rP  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2M#
Q.F  
        TextBox 220,21,40,21,.TextBox1 'default: 0 GxI!{oi2  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 y@:h4u"3  
        OKButton 40,91,90,21 ^?7-r6  
        CancelButton 190,91,90,21 CR`Q#Yi  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ):68%,  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Q4!_>YZ  
    End Dialog b"uu  
    Dim dlg As UserDialog 0$)>D==  
IS{wtuA.  
    ok = Dialog (dlg) WwBOM~/`2  
p{Yv3dNl  
    If ok=0 Then    'cancel button was pressed FaQe_;  
        Print "Execution cancelled." 2W96Zju\  
        End p;59?  
    End If oim9<_  
sV{,S>s  
    'Assign accommodation and pupil diameter & use defaults if field left empty Bs_s&a>  
    If dlg.TextBox1 = "" Then j_!F*yul  
        A = 0           'Default accommodation 7uS~MW  
    Else . y-D16V  
        A = CDbl(dlg.TextBox1) ~Ei$nV  
    End If o WrKM  
XSe=s
HEI  
    If dlg.TextBox2 = "" Then h-#6av:  
        pupilDiam = 4   'Default pupil diameter qo90t{|c  
    Else mPtZO*Fc  
        pupilDiam = CDbl(dlg.TextBox2) Q_Q''j(r6b  
    End If hk(ZM#Bh  
Pmr5S4Ka  
    Print " " @uqd.Q  
    Print "Accommodation = " & A & " Diopters" I {S;L  
    Print "Pupil Diameter = " & pupilDiam & " mm" fcRxp{*zO  
3LJ+v5T~  
    ' Calculate new parameters with accommodation j^j1  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness qPX~@^`9  

e#L8X {f  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens q#Z@+(^  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens w(*vj  
yYIf5S`V]  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens #zv3b[@  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 2\A$6N;_  
JgKO|VO  
    tlens = 3.767 + 0.04*A                  'Lens thickness -LoZs ru  
RE7?KR>  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction uB]7G0g:  
~:rl=o}  
    'Adjust parameters to account for accommodation 25nt14Y0u  
jiV<+T?  
    '************************************************************************* :j9l"5"  
    'Aqueous thickness (Position of Lens) n71r_S*  
    '************************************************************************* Xk~D$~4<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?mwt~_s9  
    GetCustomElement eID, entity w=0(<s2  
~9a<0Mc?  
    parID = FindFullName( "Geometry.Arizona Eye" ) v}}F,c(f  
Uu10)/.LC  
    ' Delete any shift(s) in z \+oQd=K@  
    count = 0  acajHs  
    While GetOperationCount(eID)>count ExY]Sdx  
        GetOperation eID, count, op GfxZ'VIn  
        If op.Type="ShiftZ" Then 9|^2",V  
            DeleteOperation eID,count <.x{|p  
            count=count-1 fy>{QC\  
        End If . oF &Ff/[  
        count=count+1 e8>})  
    Wend %~O,zs.2p  
!_]Y~[  
    'Set new shift in 9Z@hPX3.  
    op.Type = "ShiftZ" :;RMo2Tl  
    op.val1 = taq @
wGPqg  
    op.parent = parID
LiC*@W  
    AddOperation eID, op |IeTqEu9  
    Print "Set aqueous humor thickness = " & taq-0.55 \#2Z)Kz  
m4[;(1  
    '************************************************************************* OZb-:!m*  
    'Radius and conic constant of anterior lens .wEd"A&j  
    '************************************************************************* uanhr)Ys  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) !hA-_  
    GetConic eID, entity, curv, conic & TCkpS  
1jmjg~W  
    SetConic eID, entity, 1/Rant, CCant =J
]&c?I  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant D
TX0  
WA<v9#m  
    '************************************************************************* ?(@ 7r_j  
    'Radius and conic constant of posterior lens G*?8MTP8![  
    '************************************************************************* mxvp3t\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 8 `v-<J  
    GetConic eID, entity, curv, conic `[y^ :mj  
!4ocZmj\  
    SetConic eID, entity, 1/Rpost, CCpost aj-Km`5r}  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost l] K3Y\#bP  
j"8ZM{aO  
    '************************************************************************* $f$SNx)),  
    'Lens thickness (Position of posterior lens surface) gT6z9  
    '************************************************************************* @f_Lp%K  
BwN0!lsF3  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) CQc+#nRe  
WJ]T\DI  
    ' Delete any z-shift(s) :p1u(hflS  
    count = 0 %HhBt5w  
    While GetOperationCount(eID)>count 0gu_yg!R  
        GetOperation eID, count, op s-NX 
o  
        If op.Type="ShiftZ" Then >1X|^  
            DeleteOperation eID,count Gf%~{@7=u  
            count=count-1 6lZ3tdyNo  
        End If 1>.Ev,X+e  
        count=count+1 WSPI|#Xr%  
    Wend zF@/K`  
_f7 9wx\B  
    'Set new z-shift "-E\[@/  
    op.Type = "ShiftZ" =?5]()'*n  
    op.val1 = tlens h!,v/7=  
    op.parent = parID FBG4pb9=~  
    AddOperation eID, op b35fs]}u-6  
    Print "Set lens thickness = " & tlens Qry@ s5  
 >^O7  
    '************************************************************************* 8%:Iv(UMk  
    'Lens index of refraction `](e:be}  
    '************************************************************************* m%0p\Y-/  
    eID = FindMaterial( "Lens" ) Q@=Q0  
    GetModelMaterial eID, mat Mg+2. 8%  
YByLoM*  
    mat.Nd = nlens .w:DFk^E]b  
    SetModelMaterial eID, mat 6u?>M9  
    Print "Set lens index of refraction = " & nlens ),_@WW;k  
S0$8@"~=  
    '************************************************************************* GWGSd
\z  
    'Pupil diameter "BAK !N$9  
    '************************************************************************* Oz.HH  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) eB2a
-,  
(xycJ`N  
    'Adjust pupil diameter (trimming volume inner hole) //B&k`u  
6]i-E>p3R  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Q(
G#W+r  
}ZYd4h|g\z  
    ' Adjust pupil location to just in front of the lens @ 8(q$  
    parID = FindFullName( "Geometry.Arizona Eye" ) -+-?w|}qV  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) @?ebuj5{e  
    count = 0 zE*li`@  
    While GetOperationCount(eID)>count \Zk;ikEY  
        GetOperation eID, count, op C-xr"]#]  
        If op.Type="ShiftZ" Then *9 {PEx  
            DeleteOperation eID,count O}gV`q;  
            count=count-1 5; C|  
        End If ]dVGUG8  
        count=count+1 t6rRU~;}  
    Wend Fk
7?xc  
    op.Type = "ShiftZ" 39c2pV[  
    op.val1 = taq-0.01 H;mSkRD3N  
    op.parent = parID Y+pHd\$-4  
    AddOperation eID, op I]|Pq  
/*~EO{o  
    Print "Set pupil diameter = " & pupilDiam Brw@g8w-X  
RIR\']WN  
    'Update AZ Eye subassembly Description ?9vuuIE  
    eID = FindFullName( "Geometry.Arizona Eye" ) a"1t-x  
    GetEntity eID, entity NCXRevE  
    entity.Description = "Accommodation = " & A & "D" wKh4|Ka  
    SetEntity eID, entity i%iL[id:w  
LG0;#3YwH  
    Update E#34Wh2z  
    Print "DONE!" gE'sOT9v  
     lM`2sy  
End Sub /A\8 mL8  
Ha#=(9.  
如果屈光度是4，光瞳直径是4，则会输出如下数据： >fG3K`  
UsG~row:!  
Accommodation = 4 Diopters @)F)S7  
Pupil Diameter = 4 mm KRbvj  
Set aqueous humor thickness = 2.81 Xfc-UP|}  
Set anterior lens radius = 10.4 and conic constant = -2.375869 `?H]h"{7Q  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 2y\E[jA  
Set lens thickness = 3.927 d7^}tM  
Set lens index of refraction = 1.42672 r wL`Czs  
Set pupil diameter = 4 'ycJMYP8  
DONE! [|wZ77\  
';Ea?ID