[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ?TU}~}  
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。 ( 5tvfz%  
f"qga/  
模型 aC%m-m  
y0'R
mk,  
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。 }j*KcB_  
f]JM /  
A-T]9f9  
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. "CUty"R8  
>rJnayLF  
光源 E#ul IgD  
w8Sp<6*  
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。 IHJ=i-
 
%we u 1f  
/4` 0?/V  
FE2f'e  
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。 pXJpK@z  
SRrw0&ts  
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/Khw/C  
~~SwCXZ+b^  
X&0 uI*r  
B,TB3 {  
视网膜的散射 fp[|M  
34d3g  
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。 B:!W$<  
X!m9lV<  
S%yd5<%_  
]K/DY Do-  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 Yx eOI#L  
Vzwc}k*Y  
\>7^f 3m  
+TQ47Zc  
脚本 ad:&$  
k[HAkB \{  
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： .8P.)%  
Er+nk`UR_  
m"o ;L3  
Qt/8r*Oe  
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。 + j
W1V}h  
余下的脚本计算与屈光度有关的所有参数。 sK7+Q  
rxy&spX  
分析 /ig:9R  
69J4=5lX  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 sfOHarww  
Oh'Y0_oB>  
/yZQ\{=  
脚本代码 JXu$ew>q  
US%
^#D q  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. -*m+(7G\  
.]sf0S!  
Dim entity As T_ENTITY "V$Bnz\n  
Dim op As T_OPERATION %"af748!+D  
Dim mat As T_MODELMATERIAL 82]vkU  
Dim A As Double opJMS6%r  
Dim pupilDiam As Double y^}6!>Ou:  
Dim eID As Long 4=Krq6{  
Dim parID As Long sRrzp=D  
Dim count As Integer ea~:}!-P  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double )I$q5%q8  
Dim tlens As Double, nlens As Double 9$|Gfyv  
Dim curv As Double, conic As Double FDv+*sZ  
Dim ok As Long ,I_^IitN  
/Ne<V2AX  
Sub Main E Kz'&Gu  
]f_6 '|5A  
    '用户输入对话框 `zE}1M%y  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 >$,y5 AJ&  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ]sGHG^I6  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 9`w)  
        OKButton 40,91,90,21 hQDTS>U
  
        CancelButton 190,91,90,21 +C(/Lyo}  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 S-'fS2  
        TextBox 220,49,40,21,.TextBox2 'default: 4 y(=#WlK}  
    End Dialog w&B#goS  
    Dim dlg As UserDialog vJU*>U,  
0#YX=vjX7  
    ok = Dialog (dlg) OLvcivf  
@;H,gEH^  
    If ok=0 Then    'cancel button was pressed OKvPL=~  
        Print "Execution cancelled." rJ!{/3e  
        End Eyh51IB.  
    End If QtJg^2@  
^=^z1M2P  
    'Assign accommodation and pupil diameter & use defaults if field left empty *mMEl]+  
    If dlg.TextBox1 = "" Then _+^ 2^TW  
        A = 0           'Default accommodation 0sh/|`\  
    Else }A:<%N  
        A = CDbl(dlg.TextBox1) v^_mFp-}\  
    End If .^m>AKC0cX  
-pE(_  
    If dlg.TextBox2 = "" Then Cc, `}SP  
        pupilDiam = 4   'Default pupil diameter EgDQ+( -  
    Else ^+1#[E
  
        pupilDiam = CDbl(dlg.TextBox2) 9Y<#=C  
    End If W5'3$,X9  
8B#GbS K  
    Print " " WMBm6?54  
    Print "Accommodation = " & A & " Diopters" ??i4z[0M  
    Print "Pupil Diameter = " & pupilDiam & " mm" j$7Xs"
 
W.1As{  
    ' Calculate new parameters with accommodation _%x4ty  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness |/|  
[F[K^xYTlg  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens *\
o/q[  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens J-<^P5  
G5,~Z&}YS  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens |P.6<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens -dO
'~all  
B=@ jWz"  
    tlens = 3.767 + 0.04*A                  'Lens thickness B:\Uw|Mf  
/^ " 83?_  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction .?>5-od2  
V&|!RxWK  
    'Adjust parameters to account for accommodation q,3;m[cA  
S i
nl  
    '************************************************************************* F>X-w+b4r  
    'Aqueous thickness (Position of Lens) N<L`c/  
    '************************************************************************* Jz!Z2c  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) cf7v[ZZ}  
    GetCustomElement eID, entity DS-fjH\  
3F#+~^2  
    parID = FindFullName( "Geometry.Arizona Eye" ) 4A3nO<oMF  
)kJH5/  
    ' Delete any shift(s) in z 0liR  
    count = 0 U5]pi+r  
    While GetOperationCount(eID)>count m"9XT)N  
        GetOperation eID, count, op $) 5Bf3P0  
        If op.Type="ShiftZ" Then zj|/ CxV  
            DeleteOperation eID,count '>v^6iS  
            count=count-1 1,V`8 [  
        End If Ji;mHFZ*FU  
        count=count+1 2F8|I7R  
    Wend YUdxG/~'  
H\GkW6  
    'Set new shift in f2,1<^{  
    op.Type = "ShiftZ" Xm4CKuU@  
    op.val1 = taq o."rxd  
    op.parent = parID Cj*-[EL<  
    AddOperation eID, op !4rPv\
  
    Print "Set aqueous humor thickness = " & taq-0.55 Q#Y k?Kv~  
v[lnw} =m9  
    '************************************************************************* 0~&"  
    'Radius and conic constant of anterior lens (Bo bB]~a  
    '************************************************************************* L}j0a>=x4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) GyC/_ntn  
    GetConic eID, entity, curv, conic -~4+w  
w#^U45y1v  
    SetConic eID, entity, 1/Rant, CCant IF@HzT;Q  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?R5'#|EyX  
]/T-t1D  
    '************************************************************************* GPWr>B.{:S  
    'Radius and conic constant of posterior lens kHJ96G  
    '************************************************************************* 0"g@!gSrQ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 1>r ,vD&  
    GetConic eID, entity, curv, conic `Vq`z]}  
:h:@o h_=  
    SetConic eID, entity, 1/Rpost, CCpost #~Q8M*~@  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost oH2!5;A|  
s~},y]YV  
    '************************************************************************* @gSkROCdC)  
    'Lens thickness (Position of posterior lens surface) IwpbfZ  
    '************************************************************************* hFvi5I-b  
y5m!*=`l`  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" )
P=H+ #  
jK8'T_Pah  
    ' Delete any z-shift(s) J`#`fX  
    count = 0 !6w{(Rc(C  
    While GetOperationCount(eID)>count Icp0A\L@  
        GetOperation eID, count, op dZ:r&Qa  
        If op.Type="ShiftZ" Then &HM-g7|C0E  
            DeleteOperation eID,count ;5<-)  
            count=count-1 YYRT.U'  
        End If 6(sIYZ2yq  
        count=count+1 I"xWw/Ec  
    Wend Y(GN4@`S  
J<JBdk  
    'Set new z-shift _ ^7|!(Sz  
    op.Type = "ShiftZ" Wn!G.(Jq  
    op.val1 = tlens -PAF p3w\y  
    op.parent = parID fY2wDD  
    AddOperation eID, op sXl ??UGe  
    Print "Set lens thickness = " & tlens 
8o)L,{yl  
m%QqmTH  
    '************************************************************************* )Mz
t3u  
    'Lens index of refraction >Csbjf6  
    '************************************************************************* X9~m8c){z  
    eID = FindMaterial( "Lens" ) f|xLKcOP  
    GetModelMaterial eID, mat
z^sST  
${U6=  
    mat.Nd = nlens J-J3=JG  
    SetModelMaterial eID, mat b"8FlZ$  
    Print "Set lens index of refraction = " & nlens H?}wl%  
Fc0jQ@4=  
    '************************************************************************* !Y;<:zx5  
    'Pupil diameter U 5`y  
    '************************************************************************* ~SVQ;U)-  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =LZ>su  
# bX~=`  
    'Adjust pupil diameter (trimming volume inner hole) ccO aCr  
<<3+g"enno  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |#T
XE|#ux  
=cfm=+  
    ' Adjust pupil location to just in front of the lens v`)m">e*w  
    parID = FindFullName( "Geometry.Arizona Eye" ) i+~QDo(Pi  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Wp*sPZ  
    count = 0 6MrKi|'X@  
    While GetOperationCount(eID)>count ;]&-MFv#  
        GetOperation eID, count, op $P?{O3:V  
        If op.Type="ShiftZ" Then fkW(Dt,  
            DeleteOperation eID,count R!{7OkC  
            count=count-1 #t5juX9Ho9  
        End If X}apxSd"  
        count=count+1 >rwYDT#m]  
    Wend hU,$|_WDy  
    op.Type = "ShiftZ" >.Q0Tx!P  
    op.val1 = taq-0.01 PN\V[#nS  
    op.parent = parID Qp&?L"U)2  
    AddOperation eID, op ida*]+ ~  
^\YQ_/\~L  
    Print "Set pupil diameter = " & pupilDiam N^@ \tg=  
;4d.)-<No_  
    'Update AZ Eye subassembly Description N&B>#:  
    eID = FindFullName( "Geometry.Arizona Eye" ) ZA.fa0n
  
    GetEntity eID, entity Cnur"?w@o  
    entity.Description = "Accommodation = " & A & "D" y@9Y,ZR*  
    SetEntity eID, entity Kcn\g.  
fjkT5LNxk  
    Update $i&\\QNn  
    Print "DONE!" s
M9-0A  
     4? {*(  
End Sub tG 7+7Z=  
--/-D5  
如果屈光度是4，光瞳直径是4，则会输出如下数据： w$% BlqN  
W}k[slqZA  
Accommodation = 4 Diopters ,'-?:`hP'  
Pupil Diameter = 4 mm kt<@H11  
Set aqueous humor thickness = 2.81 7S2c|U4IM  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Ge9}8  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 a&:>Ped"  
Set lens thickness = 3.927 7h1"^}M&  
Set lens index of refraction = 1.42672 14u^[M"U  
Set pupil diameter = 4 -$tCF>,  
DONE! [5LMt*Y  
t!savp