[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 sZ7RiH+I  
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。 jWX^h^
n7K  
Y;B#_}yF  
模型 \U
\k$ (  
(e~vrSk+)~  
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。 aP}%&{iC*  
2\'5LL3  
9si,z  
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. |E7)s;}D  
d=$1Z.]  
光源 wfJ[" q   
c8=@s#  
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。 [h=[@ji
B  
(F.vVldBy  
n~e#Y<IP\1  
q*36/I  
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。 j\^u_D  
`JrvD  
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。 ;=ci7IT'  
|-'.\)7:  
gL-\@4\wc  
<Ky6|&!  
视网膜的散射 .:(N1n'>1  
CNRiK;nQ  
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。 ]L?DV3N  
aDr
eN*n  
UN"U#Si)  
=nTNL.SX  
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。 H>/LC* 8-  
~H+W[r}  
A8by5qU  
AWqc?K@   
脚本 oP0ZJK&;  
N`Q[OFe  
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： 61}hB>TT:  
|x ~<Dc>0*  
}K%y'D  
ktMUTL(B  
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。 HNj6Iw  
余下的脚本计算与屈光度有关的所有参数。 /cN. -lEo%  

~l=Jx*  
分析 uSRvc0R\  
{q}#  Sq  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 >aaHN1Ca  
F~Z~OqCS  
5{@Hpj/B  
脚本代码 )U':NV2  
>dTJ  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. XJ.ERLR.  
nYv`{0S+m  
Dim entity As T_ENTITY VIi/=mO]  
Dim op As T_OPERATION YhzDi>hob  
Dim mat As T_MODELMATERIAL i7RW8*  
Dim A As Double !UV/p"CfX  
Dim pupilDiam As Double k\J 6WT  
Dim eID As Long Q5N;MpJ-  
Dim parID As Long *YI>Q@F9  
Dim count As Integer Q6r!=yOEY  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double "V:24\vO  
Dim tlens As Double, nlens As Double ]DaC??%w  
Dim curv As Double, conic As Double '[6o(~*  
Dim ok As Long NSPa3NE  
xzRs;AXOp  
Sub Main W97%12J3  
)= ,Lfj8x  
    '用户输入对话框 hjgxCSp  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 oiS>:de%tc  
        TextBox 220,21,40,21,.TextBox1 'default: 0 !/},k"p6  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 %ys-y?r  
        OKButton 40,91,90,21 #{t?[JUn  
        CancelButton 190,91,90,21 P 3CzX48^  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ``:AF:  
        TextBox 220,49,40,21,.TextBox2 'default: 4 U;_b4S:  
    End Dialog LcA~a<_  
    Dim dlg As UserDialog N9M''H*VS  
iSZiJ4AUq  
    ok = Dialog (dlg) -C7IUat<  
FZEK-
]h.  
    If ok=0 Then    'cancel button was pressed ?rD`'B  
        Print "Execution cancelled." 6#JdQ[IP6  
        End R`RLq1WA  
    End If
B f_oIc  
nA\9UD<G.  
    'Assign accommodation and pupil diameter & use defaults if field left empty f.o,VVYi  
    If dlg.TextBox1 = "" Then -%U 15W;  
        A = 0           'Default accommodation Vo\RtM/6{  
    Else 5nGDt~a  
        A = CDbl(dlg.TextBox1) b$24${*'  
    End If r*'X]q|L+  
q]\bJV^/U  
    If dlg.TextBox2 = "" Then G*;}6 bj|?  
        pupilDiam = 4   'Default pupil diameter Ef1R?<  
    Else 6PS #Zydb  
        pupilDiam = CDbl(dlg.TextBox2) +n ${6/  
    End If -,;Iob56
!  
9Q#eu~R  
    Print " " Qr/8kWa0C  
    Print "Accommodation = " & A & " Diopters" EzDj,!!<w  
    Print "Pupil Diameter = " & pupilDiam & " mm" Dm=Em-ST6  
"rjqDpH  
    ' Calculate new parameters with accommodation &?@gUk74"  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ,6zH;fi  
2>.2H  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens m})q8b!S  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 5ml^3,x  
P}%0YJ$6  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens T41&;?-  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens I$Q%iZ{  
ZwLD7j*)  
    tlens = 3.767 + 0.04*A                  'Lens thickness (O N \-*  
0,T'z,
  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction pr|P#mc"J  
ZD9UE3-  
    'Adjust parameters to account for accommodation &=sVq^d@qe  
x9#>0 4s  
    '************************************************************************* T4dYC'z  
    'Aqueous thickness (Position of Lens) l_lm)'ag  
    '************************************************************************* ~HwY?[}!m  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) $XqfwlUu/4  
    GetCustomElement eID, entity No)v&P%  
7L[HtwI  
    parID = FindFullName( "Geometry.Arizona Eye" ) gc:qqJi)X  
Ul?Ha{W  
    ' Delete any shift(s) in z zfE;)K^"  
    count = 0 E6SGK,f0D  
    While GetOperationCount(eID)>count sW~Z?PFP  
        GetOperation eID, count, op Ge+&C RhyX  
        If op.Type="ShiftZ" Then B)F2SK<@  
            DeleteOperation eID,count 5#zwdoQ  
            count=count-1 1n! JfsU  
        End If OCzWP,  
        count=count+1 1NO<K`  
    Wend ny5= =C{9  
}b+tD3+  
    'Set new shift in eH2.,wY1  
    op.Type = "ShiftZ" )*@Oz  
    op.val1 = taq EO'[AU%~  
    op.parent = parID V8>%$O sw  
    AddOperation eID, op >Au]S`  
    Print "Set aqueous humor thickness = " & taq-0.55 '#SacJ\L7  
]@op  
    '************************************************************************* jg?B][  
    'Radius and conic constant of anterior lens k--.g(
T  
    '************************************************************************* Ox"4 y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) NIDK:qdR  
    GetConic eID, entity, curv, conic J!,5HJh1  
W'\{8&:!  
    SetConic eID, entity, 1/Rant, CCant =6t)-53  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant NDhHU#Q9  
yV:DR  
    '************************************************************************* 22L#\qVkl  
    'Radius and conic constant of posterior lens ^5biD9>M  
    '************************************************************************* Ys10r-kDS  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 8jxgSB",  
    GetConic eID, entity, curv, conic \xk`o5/{  
AigL:4[  
    SetConic eID, entity, 1/Rpost, CCpost JBdZ]  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /sENoQR  
M_V\mYC8I  
    '*************************************************************************
^;B vd!  
    'Lens thickness (Position of posterior lens surface) }io9Hk>|  
    '************************************************************************* w .l2  
]*pALT6  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" )  PA"xb3@I  
VAc-RaA  
    ' Delete any z-shift(s)
`gy]|gS#b  
    count = 0 HoGrvt<:.P  
    While GetOperationCount(eID)>count w}<BO> z  
        GetOperation eID, count, op ,,oiL  
        If op.Type="ShiftZ" Then m~
\BkE/[l  
            DeleteOperation eID,count 3|%Q{U  
            count=count-1 v\:>} <gc  
        End If %;9f$:U  
        count=count+1 .O'S@ %]  
    Wend q@P
5c  
02&mM%#  
    'Set new z-shift _ Onsfv  
    op.Type = "ShiftZ" uk_?2?>-5  
    op.val1 = tlens qt+vmi+~  
    op.parent = parID Ul OoMGg  
    AddOperation eID, op gOa'o<  
    Print "Set lens thickness = " & tlens ["GC   
v')Fq[H  
    '************************************************************************* c+#GX)zh\G  
    'Lens index of refraction ~f2H@#  
    '************************************************************************* {Q^P<  
    eID = FindMaterial( "Lens" ) 5)o-$1s A  
    GetModelMaterial eID, mat t/HMJ  
D0=D8P}H:  
    mat.Nd = nlens A\lnH5A  
    SetModelMaterial eID, mat +Tde#T&[  
    Print "Set lens index of refraction = " & nlens URm
x8=q  
_S/bwPj|~y  
    '************************************************************************* 4p&q
H igG  
    'Pupil diameter ;JA2n\iP,  
    '************************************************************************* ?Jm/v%0O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  =w0Rq~  
k}l5v)m  
    'Adjust pupil diameter (trimming volume inner hole) ^]^Y~$u  
!)ey~Suh  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" B+eB=KL  
d
~uK/R-KD  
    ' Adjust pupil location to just in front of the lens 8$-Wz:X&  
    parID = FindFullName( "Geometry.Arizona Eye" ) &CF74AN#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) F4>}mIA  
    count = 0 8(q4D K\5u  
    While GetOperationCount(eID)>count ^o,Hu
#  
        GetOperation eID, count, op )!hDF9O  
        If op.Type="ShiftZ" Then SQWwxFJ  
            DeleteOperation eID,count "lx}.  
            count=count-1 )-#%  
        End If ,d<wEB?\`  
        count=count+1 $jo}?Y+  
    Wend /"tVOv#  
    op.Type = "ShiftZ" AnG/A!G  
    op.val1 = taq-0.01 CT3wd?)z`  
    op.parent = parID -#j-Zo+<  
    AddOperation eID, op o;M"C[  
2sjV*\Udf  
    Print "Set pupil diameter = " & pupilDiam F
N;X"it.  
='T<jV`evu  
    'Update AZ Eye subassembly Description A5z`_b4f  
    eID = FindFullName( "Geometry.Arizona Eye" ) z<ptrH  
    GetEntity eID, entity
[zn`vT  
    entity.Description = "Accommodation = " & A & "D" l~AmHw e  
    SetEntity eID, entity a"EP`  
.Gh-T{\V'  
    Update 0XSZ3dY&+  
    Print "DONE!" EN` --^  
     iW+ZI6@  
End Sub B-|:l7  
c_x6FoE;L  
如果屈光度是4，光瞳直径是4，则会输出如下数据： :g}WN  
$d{{><  
Accommodation = 4 Diopters ?W1(
@.  
Pupil Diameter = 4 mm *J=`"^BO  
Set aqueous humor thickness = 2.81 aRdk^|}  
Set anterior lens radius = 10.4 and conic constant = -2.375869 D&0*+6j((  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ' ]l,  
Set lens thickness = 3.927 L qMH]W  
Set lens index of refraction = 1.42672 q El:2<  
Set pupil diameter = 4 0SwWLq  
DONE! H5S>|"`e`e  
zK(9k0+s