[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 Ms(xQ[#+  
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。 J}X{8Ds9  
- Fbp!*. u  
模型 ?";SUku  
hb5K"9Y  
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。 +hmFFQQ}  
ZLv/otf:|"  
Z,38eQpM  
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. 2Kz+COP+  
:OY~Q3 @  
光源 2L^)k?9>g+  
yS\&2"o  
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。 "S%t\  
FI$:R  
;Y`Y1  
lZ\8W^  
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。 5XZ!yYB?  
(G>[A}-  
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。 |:=o\eu&  
ijF_ KP'  
neDXzMxF  
tF0jH+7J-  
视网膜的散射 ~.m<`~u  
u#E'k KGO  
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。 }Q/onBt  
:jLL IqhB  
NXY jb(4:  
_95296  
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。 g\JJkXjD#  

z*eBjHbF  
&N|$G8\CY  
QOF@DvQ  
脚本 jmM|on!  
[]>'Dw_r  
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： '-;[8:y.  
qos7u91z  
afEa@et'  
Z'JS@dV  
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。 @p+;iS1}  
余下的脚本计算与屈光度有关的所有参数。 nVb@sI{{k  
|W">&Rb<t#  
分析 'YNaLZ20  
iq(PC3e`V  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Sjpx G@k  
*U?O4E9  
+2~kHrv  
脚本代码 ?{{w[U6NE  
:]^e-p!z  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. !_<6
}:ZB  
0s#72}n  
Dim entity As T_ENTITY tgK I
 
Dim op As T_OPERATION m~ tvuz I  
Dim mat As T_MODELMATERIAL sHP-@  
Dim A As Double ~Iu!B Y  
Dim pupilDiam As Double z$32rt8{`v  
Dim eID As Long gE-y`2SU  
Dim parID As Long WSkGVQu  
Dim count As Integer 'rD6MY  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double O !L`0 =%c  
Dim tlens As Double, nlens As Double *eVq(R9?T  
Dim curv As Double, conic As Double yPm2??5MW>  
Dim ok As Long l]nt@0+  
^.SY
AwL  
Sub Main "/#JC}]  
&1xCPKIr  
    '用户输入对话框 4`IM[DIG~  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 qS!r<'F3dP  
        TextBox 220,21,40,21,.TextBox1 'default: 0 7io["zW  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Ac7^JXh%
 
        OKButton 40,91,90,21
]rmBM  
        CancelButton 190,91,90,21 R$awgSE  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 d"$8-_K  
        TextBox 220,49,40,21,.TextBox2 'default: 4 J~Xv R  
    End Dialog US6_5>/  
    Dim dlg As UserDialog )s2] -n}W  
THA9OXP  
    ok = Dialog (dlg) !QUY (  
v0^9"V:y  
    If ok=0 Then    'cancel button was pressed &J[a.:..  
        Print "Execution cancelled." weitDr6  
        End Nd_fjB  
    End If 4JSPD#%f  
!XA3G`}p6s  
    'Assign accommodation and pupil diameter & use defaults if field left empty 15$xa_w}L  
    If dlg.TextBox1 = "" Then T)C@6/  
        A = 0           'Default accommodation [\uR3$j#  
    Else $6Q
IYF""  
        A = CDbl(dlg.TextBox1) 8#I>`z^F  
    End If I-7LT?r  
W+XWS,(  
    If dlg.TextBox2 = "" Then 0ju1>.p  
        pupilDiam = 4   'Default pupil diameter q>q:ZV  
    Else *
OVB;]D3+  
        pupilDiam = CDbl(dlg.TextBox2) <3YZ0f f>  
    End If k_=SDm a  
&dtk&P{  
    Print " " |Td+,>,  
    Print "Accommodation = " & A & " Diopters" ]n ?x tI  
    Print "Pupil Diameter = " & pupilDiam & " mm" #u<Qc T@  
k15vs  
    ' Calculate new parameters with accommodation z(PUoV:?  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness r@r%qkh(.@  
-@uFRQt  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ><%585  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~m%[d. }e  
yTaMlT|  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens N,ht<l\  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens B.<SC  
@|!4X(2  
    tlens = 3.767 + 0.04*A                  'Lens thickness ~iw&^p|=K  
]`o5eByo  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ?-??>& z  
xQ?>72grP  
    'Adjust parameters to account for accommodation [)H 6`w  
7AG|'s['=  
    '************************************************************************* w$gvgz  
    'Aqueous thickness (Position of Lens) e r" w{  
    '************************************************************************* \lL[08G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) r4.6W[|d  
    GetCustomElement eID, entity 7GA8sK  
J5@08bZm  
    parID = FindFullName( "Geometry.Arizona Eye" ) )W@ug,y  
 Xo^8o0xi  
    ' Delete any shift(s) in z +^I0>\  
    count = 0 6K2e]r  
    While GetOperationCount(eID)>count D6SUzI1+H  
        GetOperation eID, count, op E}^V@ :j>  
        If op.Type="ShiftZ" Then |%_C$s%  
            DeleteOperation eID,count +vc+9E.?9  
            count=count-1 8K8u|]i  
        End If ,"qCz[aDN1  
        count=count+1
I?KN7(9u?  
    Wend %lKw+D  
GR,2^]<{  
    'Set new shift in pP\Cwo #,
 
    op.Type = "ShiftZ" {1GJ,['qL  
    op.val1 = taq $Dg-;I  
    op.parent = parID r}U6LE?>  
    AddOperation eID, op %wD#[<BGn>  
    Print "Set aqueous humor thickness = " & taq-0.55 D(cD8fn,J  
,n|si#  
    '************************************************************************* 68%aDs  
    'Radius and conic constant of anterior lens IrwQ~z3I  
    '************************************************************************* c '|*{%<e2  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) _h%Jf{nu  
    GetConic eID, entity, curv, conic W5jwD  
Y
MGy-]!o  
    SetConic eID, entity, 1/Rant, CCant .j6udiv5  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant GT>'|~e  
wG3L+[,  
    '************************************************************************* E4#{&sRT  
    'Radius and conic constant of posterior lens aRd~T6I  
    '************************************************************************* iUKjCq02  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ci,(]T+!  
    GetConic eID, entity, curv, conic h yrPu_  
+in)(a.  
    SetConic eID, entity, 1/Rpost, CCpost $e^"Inhtqp  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ulR yt^bx|  
UlXm4\@  
    '************************************************************************* 31n"w;  
    'Lens thickness (Position of posterior lens surface) ;_sJ>.=\  
    '************************************************************************* 7o4E_ .*  
7
uBx  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) YSjc=  
KdNo'*;U]_  
    ' Delete any z-shift(s) wGHft`Z  
    count = 0 o)Q4+njT@  
    While GetOperationCount(eID)>count 2"0VXtv6  
        GetOperation eID, count, op 2OG/0cP  
        If op.Type="ShiftZ" Then 3=S|U,  
            DeleteOperation eID,count ^&3vGu9  
            count=count-1 xvGYd,dlK  
        End If "|\hTRQ  
        count=count+1 lL}6IZ5sb  
    Wend ]4rmQAS7"  
s>9I#_4]  
    'Set new z-shift :?f<tNU$  
    op.Type = "ShiftZ" Rtf<UhUn  
    op.val1 = tlens 2%/F`_XbP  
    op.parent = parID +\dVC,,=^g  
    AddOperation eID, op lp*5;Ls'q  
    Print "Set lens thickness = " & tlens /%YW[oY{V  
l&& i`  
    '************************************************************************* ^Ks1[xc*`  
    'Lens index of refraction A-x^JC=  
    '************************************************************************* at>_EiS  
    eID = FindMaterial( "Lens" ) UG v
IHm  
    GetModelMaterial eID, mat r*HSi.'21  
,~L*N*ML  
    mat.Nd = nlens /fQcrd7h  
    SetModelMaterial eID, mat ~|u;z,\  
    Print "Set lens index of refraction = " & nlens W83d$
4\d  
p{?duq=  
    '************************************************************************* R6~6b&-8  
    'Pupil diameter ;5X6`GlS#5  
    '************************************************************************* ZfM]A)  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) -6MPls+  
AA-$;s  
    'Adjust pupil diameter (trimming volume inner hole) 4'faE="1)S  
% :G78.  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" p5In9s  
;&lXgC^*  
    ' Adjust pupil location to just in front of the lens %+r(*Q+0$f  
    parID = FindFullName( "Geometry.Arizona Eye" ) $GoS?\G  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) c coi  
    count = 0 hl]d99Lc  
    While GetOperationCount(eID)>count B"v*[p?  
        GetOperation eID, count, op #jbC@A9Pe  
        If op.Type="ShiftZ" Then /{R ^J#  
            DeleteOperation eID,count U" @5R[=F-  
            count=count-1 g.\b@0Uy'  
        End If
:7@[=n
  
        count=count+1 WjBml'^RY  
    Wend erI&XI  
    op.Type = "ShiftZ" y^r'4zN'  
    op.val1 = taq-0.01 Cq@7oi]W0  
    op.parent = parID fD%/]`y  
    AddOperation eID, op .p{l
zI9  
ErN[maix#  
    Print "Set pupil diameter = " & pupilDiam #h ud_  
r6j[C"@  
    'Update AZ Eye subassembly Description >MJ%6A>  
    eID = FindFullName( "Geometry.Arizona Eye" ) =Vh]{y~$  
    GetEntity eID, entity JP!e'oWxi  
    entity.Description = "Accommodation = " & A & "D" nANl9;G  
    SetEntity eID, entity hl[<o<`Q  
u%L6@M2  
    Update A._CCou  
    Print "DONE!" !,-'wT<v  
     0ytAn+/"x  
End Sub N+V#=Uy  
+4J'> dr  
如果屈光度是4，光瞳直径是4，则会输出如下数据： yS)k"XNb  
g=KK PSK  
Accommodation = 4 Diopters "eoPG#]&  
Pupil Diameter = 4 mm VI3fvGHat{  
Set aqueous humor thickness = 2.81 j gV^{8qG  
Set anterior lens radius = 10.4 and conic constant = -2.375869 TaF*ZT2  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 }P=FMme{F(  
Set lens thickness = 3.927 ko.%@Y(=  
Set lens index of refraction = 1.42672 qV=O;  
Set pupil diameter = 4 e_Zs4\^ef  
DONE!
EAY+#>L*  
oe6Ex5h