[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 wx^Det  
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。 Sl/]1[|mb  
, #=TputM  
模型 )r^vrCNy>  
w"5Eyz-eO  
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。 fLnwA|n=  
?7}ybw3t]  
C$q};7b1N  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. >TMd1?,  
;plBo%EBV  
光源 Z#.1p'3qm1  
^D<CoxG  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 nfbR"E jXr  
fcxg6W'  
D(l,Z  
eZEk$W%  
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。 ,`JYFh M  
VwpC UW  
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。 <l(n)|H1P  
&#L C'  

.u>[m.  
rCwE$5 b  
视网膜的散射 hs[x\:
})/  
d\uN  
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。  
4d\^  
+q'\rpt  
}/dk2!?ig  
t5%cpkgh4  
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。 +l^tT&s;f  
ffG<hclk  
+@=V}IO  
?V,q&=9  
脚本 E{EO9EI  
~4khIz  
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： XjF@kQeM=  
*#'j0;2F  
-Y@tx fu-  
\?; `_E`j  
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。 YZ5,K6u  
余下的脚本计算与屈光度有关的所有参数。 #m,H1YH M  
]R_R`X?  
分析 R|n  
"aOs#4N  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 N2O *g`YC  
<mQXS87  
sSZ)C|Q  
脚本代码 ?>Sv_0  
T[Zs{S  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. &J)<1!|  
uR ?W|a  
Dim entity As T_ENTITY eJ99W=  
Dim op As T_OPERATION H"FK(N\  
Dim mat As T_MODELMATERIAL .JPN';  
Dim A As Double X>8,C^~$1  
Dim pupilDiam As Double B:Ts_9*  
Dim eID As Long 2 ^m}5:0  
Dim parID As Long G9f
6'5 O  
Dim count As Integer sq!$+=1-X  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5Jbwl$mZ  
Dim tlens As Double, nlens As Double 3]l)uoNt/  
Dim curv As Double, conic As Double D`T;j[SsS#  
Dim ok As Long SI=$s>1  
g}NO$?ndg  
Sub Main fZ$
b8  
umIGI  
    '用户输入对话框 i)?7+<X  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 C`hdj/!A  
        TextBox 220,21,40,21,.TextBox1 'default: 0 23wztEp{a  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 6nZ]y&$G-k  
        OKButton 40,91,90,21 e0TYHr)X>3  
        CancelButton 190,91,90,21 C(ij_>  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 UGSZg|&6#*  
        TextBox 220,49,40,21,.TextBox2 'default: 4 &"^F;z/  
    End Dialog hZx&j{  
    Dim dlg As UserDialog 8M99cx*K  
WO_Uc_R  
    ok = Dialog (dlg) *4}_2"[  
<0})%V?-  
    If ok=0 Then    'cancel button was pressed sp,-JZD  
        Print "Execution cancelled." r[S(VPo[()  
        End CRK%^3g  
    End If 9MMCWMV  
2!{D~Gfl=  
    'Assign accommodation and pupil diameter & use defaults if field left empty yp#!$+a}  
    If dlg.TextBox1 = "" Then AJ\&>6GZ(b  
        A = 0           'Default accommodation Cz0FA]-g  
    Else lL}NiN-)t  
        A = CDbl(dlg.TextBox1) IrMHAM5K  
    End If h[W`P%xZ  
hzo> :U  
    If dlg.TextBox2 = "" Then x4WCAqi/2  
        pupilDiam = 4   'Default pupil diameter ubwM*P  
    Else aV\i3\da  
        pupilDiam = CDbl(dlg.TextBox2) n9B5D:.G  
    End If X'`n>1z  
 0k (-  
    Print " " rYb5#aT[  
    Print "Accommodation = " & A & " Diopters" wZ(1\ M(  
    Print "Pupil Diameter = " & pupilDiam & " mm" lq-KM
8j  
}u_D{bz  
    ' Calculate new parameters with accommodation ANhqS  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 8A#,*@V[  
W/qXQORv  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens cnu&!>8V  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens o701RG~)  
` ,\b_SFg  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ?2]fE[SqY  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens g(@F`W[  
,"EaZ/Bl/  
    tlens = 3.767 + 0.04*A                  'Lens thickness > Vm}u`x  
TxJk.
c  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction _4by3?
<c  
P~j#8cH7  
    'Adjust parameters to account for accommodation Db|f"3rq?  
Nx 42k|8  
    '*************************************************************************
wW%b~JX  
    'Aqueous thickness (Position of Lens) 0~U#DTx0  
    '************************************************************************* =-r"@2HBq  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Rw?w7?I  
    GetCustomElement eID, entity o%_-u +  
s<!A<+Sh  
    parID = FindFullName( "Geometry.Arizona Eye" ) L^JU{\C  
ZFtx&vrP  
    ' Delete any shift(s) in z ~su>RolaX  
    count = 0 Gd
ow[x  
    While GetOperationCount(eID)>count [+\He/M6  
        GetOperation eID, count, op eKiDc=@  
        If op.Type="ShiftZ" Then w|f+OlPXq  
            DeleteOperation eID,count % !@E)%d0  
            count=count-1 <f>77vh0  
        End If tK3$,9+  
        count=count+1 fEBi'Ad  
    Wend Qsbyy>o)  
[j6]!p]S$  
    'Set new shift in G#%Sokkb'  
    op.Type = "ShiftZ" I'5[8  
    op.val1 = taq Ae2N"%Ej  
    op.parent = parID =F\Xt "  
    AddOperation eID, op F@<cp ?dR  
    Print "Set aqueous humor thickness = " & taq-0.55 JG;}UuHYM  
U^_\V BAk  
    '************************************************************************* <WUg
H6"  
    'Radius and conic constant of anterior lens f#l9rV"@g  
    '************************************************************************* tR!C8:u  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) <-1:o*8:}  
    GetConic eID, entity, curv, conic /we]i1-9  
Mi.#x_  
    SetConic eID, entity, 1/Rant, CCant fM.#FT??  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Uh.swBC n  
|sGJum&=  
    '************************************************************************* .i;.5)shsu  
    'Radius and conic constant of posterior lens fq>{5ODO  
    '************************************************************************* AWcbbj6Nd  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) `+Nv=vk  
    GetConic eID, entity, curv, conic g[~{iu_$d  
#w''WOk@ZG  
    SetConic eID, entity, 1/Rpost, CCpost "M:ui0YP  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Z`kVyuQ  
+(!/(2>~  
    '************************************************************************* u0W6u} 4;  
    'Lens thickness (Position of posterior lens surface) Z(q]rX5"  
    '************************************************************************* qlM<X?  
~C{:G;Iy0  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {+lU4u  
4rDVCXE  
    ' Delete any z-shift(s) GJ
dL1ptc  
    count = 0 }k.yLcXM  
    While GetOperationCount(eID)>count e#hg,I  
        GetOperation eID, count, op :?UcD_F  
        If op.Type="ShiftZ" Then >)D=PvGlmp  
            DeleteOperation eID,count Ko&4{}/  
            count=count-1 =R:O`qdC4e  
        End If @:im/SE  
        count=count+1 +o@:8!IM1  
    Wend w7`pbcY,  
4M%|N  
    'Set new z-shift BvvjaC  
    op.Type = "ShiftZ" `Hw][qy#  
    op.val1 = tlens -~c-mt  
    op.parent = parID Z'A 3\f   
    AddOperation eID, op 3rK\ f4'  
    Print "Set lens thickness = " & tlens bj`GGxzOb  
Hya.OW{  
    '************************************************************************* 8d$|JN;)  
    'Lens index of refraction kB?/_a`]  
    '************************************************************************* <cZ/_+H%
C  
    eID = FindMaterial( "Lens" ) i+(>w'=m  
    GetModelMaterial eID, mat sf$hsPC^  
P84YriLo  
    mat.Nd = nlens (Q*x"G#4>  
    SetModelMaterial eID, mat r?u4[ Oe#  
    Print "Set lens index of refraction = " & nlens +8
xT}mX  
dG+$!*6Z  
    '************************************************************************* N( 7(~D=)B  
    'Pupil diameter 3XB`|\:  
    '************************************************************************* )o:sDj`b]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &bq1n_  
R<fF ^^  
    'Adjust pupil diameter (trimming volume inner hole) dfAw\7v/  
#do%u"q  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" @-K[@e/uwy  
i+5Qs-dHA  
    ' Adjust pupil location to just in front of the lens [f\Jcjc  
    parID = FindFullName( "Geometry.Arizona Eye" ) 9:g A0Z  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) YFu>`w^Y  
    count = 0 ]["%e9#aX  
    While GetOperationCount(eID)>count ,){#
J"W  
        GetOperation eID, count, op T*@o?U  
        If op.Type="ShiftZ" Then #qk=R7"Q  
            DeleteOperation eID,count MA_YMxP.'  
            count=count-1 VMF?qT3Nd  
        End If Q_p&~PNy5  
        count=count+1 =}tomN(F~[  
    Wend Kn3Xn`P?  
    op.Type = "ShiftZ" 3=U#v<  
    op.val1 = taq-0.01 DZmVm['l  
    op.parent = parID I*j~5fsS'  
    AddOperation eID, op a~@f,bw  
] 7[#K^  
    Print "Set pupil diameter = " & pupilDiam VOC$Kqg;  
>`3F`@1L0  
    'Update AZ Eye subassembly Description A",}Ikh='`  
    eID = FindFullName( "Geometry.Arizona Eye" ) Y,L[0%  
    GetEntity eID, entity iVnMn1h  
    entity.Description = "Accommodation = " & A & "D" lO|LvJyx  
    SetEntity eID, entity "6IZf>N@#  
_\yR/W~  
    Update L<oQKe7Q:  
    Print "DONE!" A`M-N<T  
     [;aM8N  
End Sub 
)H]L/n  
s>G]U)d<'  
如果屈光度是4，光瞳直径是4，则会输出如下数据： }D!tB  
b3_P??yp  
Accommodation = 4 Diopters Bx\ o8k  
Pupil Diameter = 4 mm 9;I%Dv  
Set aqueous humor thickness = 2.81 Q=%W-  
Set anterior lens radius = 10.4 and conic constant = -2.375869 0\"#Xa+}8  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &c"!Y)%G  
Set lens thickness = 3.927 ?7)v:$
(G}  
Set lens index of refraction = 1.42672 |J`v w  
Set pupil diameter = 4
VJw7defc  
DONE! )c*xKij  
Gjq7@F'