[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 O.Xhi+  
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。 tR`^c8gD  
&6q67  
模型 Lsb`,:  
P4{!
/&/  
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。 F+Q(^Nk  
vg;9"A!(  
/k O <o&  
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. p%ZOLoc)Y  
VteMsL/H  
光源 Lh rU fy  
}2+*E}g  
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。 GMW,+  
# ;3v4P  
jWNF3\  
h= Mmd  
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。 X 3q2XU  
bJ5 VlK67R  
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。 q'1 86L87  
 Xn=  
YG K7b6  
Of.%rpgy  
视网膜的散射 uG,*m'x']  
={[9kR i  
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。 1.IEs:(;  
*w5xC5*  
Gk-49|qIV  
,%<ICusZ  
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。 D7|qFx;]g  
hywy(b3  
HVH<S  
Aw"Y_S8.  
脚本 &MJcLM]  
!cNw8"SIU  
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： 4#Cm5xAt6  
Cc&SHG*R  
w 21g&  
-F`uz,wZ  
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 TMJ.;  
余下的脚本计算与屈光度有关的所有参数。 vugGMP;D(  
ocPM zq-  
分析 |*v w(  
:878q TB  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 [Ufx=BPx3  
&e)V!o@wJV  
Lpv,6#m`)  
脚本代码 R4g;-Ci->  
lcfX(~/m^  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. H7CWAQPfj  
,-`A6ehg  
Dim entity As T_ENTITY fjh,e  
Dim op As T_OPERATION nxhn|v  
Dim mat As T_MODELMATERIAL ;i-<dAV8B  
Dim A As Double Gc,6;!+(  
Dim pupilDiam As Double m<I>NYfE  
Dim eID As Long HApjXv!U[  
Dim parID As Long lN~u='
Kc  
Dim count As Integer pE381Cw  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double GZzBATx  
Dim tlens As Double, nlens As Double QE4TvnhK  
Dim curv As Double, conic As Double wu~?P`  
Dim ok As Long <~}NxY\5  
ypLt6(1j%  
Sub Main OJT%?P%@{  
K9QC$b9(  
    '用户输入对话框 L]wk Ba  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 75W@B}dZd  
        TextBox 220,21,40,21,.TextBox1 'default: 0 LO@o`JF  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 $0&<Jx  
        OKButton 40,91,90,21 '7JM/AcC#K  
        CancelButton 190,91,90,21 A@Zs
L  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 >)6k)$x%%  
        TextBox 220,49,40,21,.TextBox2 'default: 4 9}$'q$0R]  
    End Dialog :wY(</H  
    Dim dlg As UserDialog wo5fGQJ
 
e)f!2'LL  
    ok = Dialog (dlg) bBY7^k  
SQ-CdpT<  
    If ok=0 Then    'cancel button was pressed Dio)orc  
        Print "Execution cancelled." D9%t67s  
        End %*];XpAE  
    End If {]Ec:6  
[!Zyp`:  
    'Assign accommodation and pupil diameter & use defaults if field left empty FJ] ?45  
    If dlg.TextBox1 = "" Then ~S~4pK  
        A = 0           'Default accommodation tqXCj}mR  
    Else mWTV)z57  
        A = CDbl(dlg.TextBox1) 8A: =#P^O\  
    End If irF+(&q]jh  
$Gs|Z$(  
    If dlg.TextBox2 = "" Then +wGFJLHJ  
        pupilDiam = 4   'Default pupil diameter Bmv5yc+;  
    Else NeR1}W  
        pupilDiam = CDbl(dlg.TextBox2) 'Esz#@R  
    End If ( 9(NP_s  
_rz7)%Y'#$  
    Print " " {sF;R.P&r  
    Print "Accommodation = " & A & " Diopters" @dc4v_9  
    Print "Pupil Diameter = " & pupilDiam & " mm" [z,6K=  
e'2w-^7  
    ' Calculate new parameters with accommodation Ntlbn&lc;D  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness n
K6(0?/  
O{Y*a )"  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens q"VC#97`  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens TJUYd9O4[  
?*:BgaR_  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ^?S 
lM  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Cuc+9  
4^7*R  
    tlens = 3.767 + 0.04*A                  'Lens thickness #B5-3CwB  
"0m\y+%8  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 8=-#LVo~c  
#&snl  
    'Adjust parameters to account for accommodation :czUOZ_  
Bpp(5  
    '************************************************************************* /mwsF]Y  
    'Aqueous thickness (Position of Lens) ld7B{ ?]  
    '************************************************************************* [<.dOe7|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) $|VD+[jSV  
    GetCustomElement eID, entity jH[{V[<#X  
;CDa*(e  
    parID = FindFullName( "Geometry.Arizona Eye" ) ;aDYw [  
=U}!+ 8f  
    ' Delete any shift(s) in z { {+:Vy  
    count = 0 +r$VrNVs  
    While GetOperationCount(eID)>count /! M%9gu  
        GetOperation eID, count, op Cf.(/5X  
        If op.Type="ShiftZ" Then $fwj8S7$  
            DeleteOperation eID,count naM=oSB(  
            count=count-1 em
G1Wyl  
        End If c>+hY5?C  
        count=count+1 m6o o-muAr  
    Wend B3Ws)nF"  
o"g<Vz  
    'Set new shift in OySn[4`(i  
    op.Type = "ShiftZ" qv8B$}FU  
    op.val1 = taq gM&4Ur  
    op.parent = parID ;RS^^vDm  
    AddOperation eID, op Vo9FlYj  
    Print "Set aqueous humor thickness = " & taq-0.55 :8Ugz~i  
R]N"P:wf@  
    '************************************************************************* 8xx2+  
    'Radius and conic constant of anterior lens F@1Eg
  
    '************************************************************************* !-tVt D  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^t P|8k  
    GetConic eID, entity, curv, conic 9j<7KSj  
^]9.$$GU\A  
    SetConic eID, entity, 1/Rant, CCant 5 ~YaXh^  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant G!U `8R  
><{Lh@{  
    '************************************************************************* c.uD%  
    'Radius and conic constant of posterior lens Z@bKYfGM  
    '************************************************************************* vY]7oX+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) E2Ec
`o  
    GetConic eID, entity, curv, conic rhC x&L  
8>'vzc/*>  
    SetConic eID, entity, 1/Rpost, CCpost J'*`K>wV  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost i*e'eZ;
)  
bl[2VM7P  
    '************************************************************************* gt!tDu  
    'Lens thickness (Position of posterior lens surface) EO"G(v  
    '************************************************************************* r[3 2'E  
m5lTf
 
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4)d"}j  
PDpDkcy|QM  
    ' Delete any z-shift(s) JxQGL{) >  
    count = 0 )odz/\9n3c  
    While GetOperationCount(eID)>count R?8/qGSVqJ  
        GetOperation eID, count, op K5 Z'kkOk  
        If op.Type="ShiftZ" Then lGX8kAv?  
            DeleteOperation eID,count DS=Dg@y  
            count=count-1 RH"EO4  
        End If "BvDLe':  
        count=count+1 h-5] nL3  
    Wend t^7}j4lk  
GhW{6.^  
    'Set new z-shift 4x_# 1 -  
    op.Type = "ShiftZ" Oox,4
&  
    op.val1 = tlens gCM(h[7A  
    op.parent = parID f&? 8fB8{  
    AddOperation eID, op 7%i6zP/a  
    Print "Set lens thickness = " & tlens 3H`ES_JL  
) -@Dh6F  
    '************************************************************************* Z"E2ZSa0  
    'Lens index of refraction h`:B8+k  
    '************************************************************************* ] jycg@=B  
    eID = FindMaterial( "Lens" ) x%55:8{  
    GetModelMaterial eID, mat ?A~a}bFZ  
dwVo"_Yr  
    mat.Nd = nlens E*83N@i  
    SetModelMaterial eID, mat >C -N0H
 
    Print "Set lens index of refraction = " & nlens s;xErH@RA  
>H,PST  
    '************************************************************************* jNW/Biy4u  
    'Pupil diameter Cd7l+~*Y  
    '************************************************************************* fi'\{!!3m^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) :YNXS;>)!  
eI+p  
    'Adjust pupil diameter (trimming volume inner hole) v.Xmrry  
>/y+;<MZ  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :{~TG]4M  
/y-8dgv0a  
    ' Adjust pupil location to just in front of the lens w s7LDY&(  
    parID = FindFullName( "Geometry.Arizona Eye" ) X,`e1nsR  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) lfte  
    count = 0 IvM>z03  
    While GetOperationCount(eID)>count E*8).'S%k  
        GetOperation eID, count, op VevDW }4q*  
        If op.Type="ShiftZ" Then Pi=B\=gs  
            DeleteOperation eID,count Z)G@ahOQ  
            count=count-1 mh8)yy5\  
        End If <Y^)/ s  
        count=count+1 EN)0b,ax  
    Wend }?[a>.]u  
    op.Type = "ShiftZ" en29<#8TO  
    op.val1 = taq-0.01 d.p%jVO)"  
    op.parent = parID lVS.XQ2<  
    AddOperation eID, op xU'% 6/G  
6='x}Qb\H  
    Print "Set pupil diameter = " & pupilDiam m]/sR3yF  
S3?U-R^`  
    'Update AZ Eye subassembly Description qfyuq]  
    eID = FindFullName( "Geometry.Arizona Eye" ) }M~[8f ]  
    GetEntity eID, entity nrCr9#  
    entity.Description = "Accommodation = " & A & "D" a<&GsDw  
    SetEntity eID, entity 2~QN#u|UC3  
u-HBmL  
    Update N@\`DO  
    Print "DONE!" 1IWP~G  
     $ cYKVhf  
End Sub ?Z"<&ts
Z  
<xr\1VjA  
如果屈光度是4，光瞳直径是4，则会输出如下数据： %#@5(_'  
&#<>fT_  
Accommodation = 4 Diopters ~A-D>.ZH  
Pupil Diameter = 4 mm zl!Y(o!@  
Set aqueous humor thickness = 2.81 e%JH q  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ![{0Yw D  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Wh1'?#  
Set lens thickness = 3.927 OLyl.#J  
Set lens index of refraction = 1.42672 v)rQ4 wD:  
Set pupil diameter = 4 SJ8|~,vL  
DONE! wU/BRz8I  
7^DN8g"&\