[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 @U.}Ei  
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。 kd4*Zab  
FEi,^V  
模型 Y&Vbf>Hi+  
x 3co?  
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。 %
>:)
4A  
2uR4~XjF  
nz?BLO=  
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. 4Jy,IKPp  
xcRrI|?eC  
光源 }~,cCtg:o  
!<^j!'2  
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。 t:@A)ip  
=xWW+w!r  
<?@46d?C  
ZZJ"Ny.2  
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。 ..{^"
`FQ  
.0;k|&eBD  
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。 #K*q(ei,7h  
tfIBsw.  
!Kqj&y5  
WG=r? xE  
视网膜的散射 @y2Bq['  
{
ZI6!zh'  
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。 
Vw@
x  
;j\$[4W.i  
hpes  
2Sd6b 2-  
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。 Vk=<,<BB  
_IGa8=~  
" yl"A4p S  
j|8{Vyqd  
脚本 X"59`Yh  
@!HMd{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： ptL}F~  
BnY|t2r  
*"L:"i`*$  
3/<^R}w\  
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~> #{"C  
余下的脚本计算与屈光度有关的所有参数。 WZ-{K"56  
5.UgJ/  
分析 *Z(C')7r  
l_IX+4(@b|  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 !Bbwl-e`  
.y/?~+N^  
jl29~^@}1i  
脚本代码 itM
c!bUQ  
}+Z;zm@/6  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. ;]o^u.PC  
\:28z
  
Dim entity As T_ENTITY UZ0O j5B.  
Dim op As T_OPERATION ,fLe%RP  
Dim mat As T_MODELMATERIAL G?
(:Z=  
Dim A As Double {D
.0_=y~2  
Dim pupilDiam As Double pMrfi}esx  
Dim eID As Long e+aQ$1^t  
Dim parID As Long #?|z&
9  
Dim count As Integer ZWW}r~d{  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double r{;4(3E2  
Dim tlens As Double, nlens As Double skArocs  
Dim curv As Double, conic As Double [$+61n}.12  
Dim ok As Long zOp"n\  
N=x,96CF  
Sub Main K",]_+b  
@isqFKjph  
    '用户输入对话框 YR#1[fe*_  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ~qxc!k!w4  
        TextBox 220,21,40,21,.TextBox1 'default: 0 GoXHVUyp  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^<b.j.$<z  
        OKButton 40,91,90,21 CtxK{:  
        CancelButton 190,91,90,21 EFOQ;q  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 M,lu)~H  
        TextBox 220,49,40,21,.TextBox2 'default: 4 x&p=vUuukP  
    End Dialog |%9~W^b  
    Dim dlg As UserDialog Dn!V)T  
sNTfRPC
 
    ok = Dialog (dlg) 1 crjRbi  
w|#79,&  
    If ok=0 Then    'cancel button was pressed "fwuvT 1  
        Print "Execution cancelled." ThB2U(Wf  
        End EaL+}/q&  
    End If '93&?  
O;tn5  
    'Assign accommodation and pupil diameter & use defaults if field left empty 4 .qjTR  
    If dlg.TextBox1 = "" Then }=)"uv  
        A = 0           'Default accommodation m 9Q{)?J7  
    Else %M:"Ai5:  
        A = CDbl(dlg.TextBox1) )A"7l7?.n)  
    End If 2|EoP-K7  
%J'_c|EQM  
    If dlg.TextBox2 = "" Then A&#Bf#!G  
        pupilDiam = 4   'Default pupil diameter }%|OnEk"  
    Else ],m-,K  
        pupilDiam = CDbl(dlg.TextBox2) ,;}RIcvQV  
    End If -ybupUJcbv  
%*hBrjbj  
    Print " " ,kI1"@Tu  
    Print "Accommodation = " & A & " Diopters" xCD+qP^  
    Print "Pupil Diameter = " & pupilDiam & " mm" g'@+#NMw  
V00zk`PH  
    ' Calculate new parameters with accommodation &bNj/n/  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness AmFHn  
z'*>Tk8h  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens "tIx$?I  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens FeJ5^Gh.  
p-_j0zv  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 9:>vl0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens #t*c*o  
Urr1K)  
    tlens = 3.767 + 0.04*A                  'Lens thickness "
~6BC  
E&AR=yqk  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction "`wq:$R  
"k/x+%!Spc  
    'Adjust parameters to account for accommodation *@Z'{V\  
dEnhNPeRl  
    '************************************************************************* ubw ]}sfM#  
    'Aqueous thickness (Position of Lens) Z'~FZRF  
    '************************************************************************* bBf+z7iyc  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) el<nY"c  
    GetCustomElement eID, entity sQ$FtKm6  
s&l[GKR  
    parID = FindFullName( "Geometry.Arizona Eye" ) nK[$ID  
Y;WrfO$J  
    ' Delete any shift(s) in z :0l(Ll KD  
    count = 0 0 N(2[s_A  
    While GetOperationCount(eID)>count >=
(e}~5y  
        GetOperation eID, count, op (`N/1}vk  
        If op.Type="ShiftZ" Then xHmc8G$zu  
            DeleteOperation eID,count
_<$=n6#  
            count=count-1 3 ren1   
        End If +}!eAMQ  
        count=count+1 VI4d/2e  
    Wend i8]r}a  
~tWBCq 6  
    'Set new shift in POf \l  
    op.Type = "ShiftZ" l d@^$  
    op.val1 = taq ^/,s$dj  
    op.parent = parID W~qo `r  
    AddOperation eID, op Hcpw[%(  
    Print "Set aqueous humor thickness = " & taq-0.55 F&\o1g-L  
'nul{RE*  
    '************************************************************************* Kj7Osqu2bE  
    'Radius and conic constant of anterior lens )]}*oO  
    '************************************************************************* sC$X7h(Q+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) m-:k]9I  
    GetConic eID, entity, curv, conic s}.nh>Q  
(]JJ?aAF  
    SetConic eID, entity, 1/Rant, CCant er_aol e  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant cb+!H>+  
@1pdyKK  
    '************************************************************************* ^ZsME,  
    'Radius and conic constant of posterior lens P_;oSN|>  
    '*************************************************************************
nL$tXm-x  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) BBX4^;t  
    GetConic eID, entity, curv, conic {|fA{ Q_R  
1Dbe0u  
    SetConic eID, entity, 1/Rpost, CCpost c}Qc2D3*  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost *?uF&( 0  
F'K{=  
    '************************************************************************* 9'tM65
K  
    'Lens thickness (Position of posterior lens surface) zUh(b=,  
    '************************************************************************* ,Ya&M@^Z  
3K'3Xp@A  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZE :oK  
-{O2Nv-]]  
    ' Delete any z-shift(s) dO=<3W  
    count = 0 2XE4w# [j  
    While GetOperationCount(eID)>count \nLO.,  
        GetOperation eID, count, op H=dj\Br`  
        If op.Type="ShiftZ" Then Bg3^BOT  
            DeleteOperation eID,count n4:WM+f4  
            count=count-1 [~J4:yDd=  
        End If WN0^hDc-  
        count=count+1 ZK;HW  
    Wend k~?@~xm,R  
>Nov9<p  
    'Set new z-shift 'HC4Q{b`  
    op.Type = "ShiftZ" wC[J=:]tA5  
    op.val1 = tlens &
1I0i[R  
    op.parent = parID 4-TM3Cw`d&  
    AddOperation eID, op }/=VnCfU  
    Print "Set lens thickness = " & tlens 'd28YjtoX  
F4k`x/ak  
    '************************************************************************* $}&6p6|  
    'Lens index of refraction _K9jj  
    '************************************************************************* /g_}5s-Z  
    eID = FindMaterial( "Lens" ) n>@(gDq
  
    GetModelMaterial eID, mat ThHK1{87X}  
uv@4/M`  
    mat.Nd = nlens ]-O:|q>]  
    SetModelMaterial eID, mat 7==Uoy*O  
    Print "Set lens index of refraction = " & nlens $GcVC (]  
# wG}T .*  
    '************************************************************************* rUj]6j=e  
    'Pupil diameter rc$G0O  
    '************************************************************************* {RzlmDStV  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) b[/-lNrc  
UCl,sn  
    'Adjust pupil diameter (trimming volume inner hole) `=FfzL  
s Ce{V*ua  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"
\}cEHLq  
/{Nx%PqL  
    ' Adjust pupil location to just in front of the lens IQR?n}ce  
    parID = FindFullName( "Geometry.Arizona Eye" ) Jo2:0<VL  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) <%|2yPb]  
    count = 0 3.8d"  
    While GetOperationCount(eID)>count WT1ch0~2  
        GetOperation eID, count, op E$RH+):|  
        If op.Type="ShiftZ" Then chxO*G  
            DeleteOperation eID,count vmL0H)q  
            count=count-1 %POoyH@D}  
        End If ^xFZ;Yf  
        count=count+1 g&&5F>mF  
    Wend ^hLAMaR  
    op.Type = "ShiftZ" 10t9Qv/  
    op.val1 = taq-0.01 H htAD Y  
    op.parent = parID y1z4qSeM  
    AddOperation eID, op aO6w:IO  
}fdo Aid~  
    Print "Set pupil diameter = " & pupilDiam :IvKxOv  
:Fu.S1j$  
    'Update AZ Eye subassembly Description dy`K5lC@  
    eID = FindFullName( "Geometry.Arizona Eye" ) >}Fe9Y.o  
    GetEntity eID, entity g"^<LX-  
    entity.Description = "Accommodation = " & A & "D" 9*U3uyPi  
    SetEntity eID, entity m&cVda/  
HvLvSy1U  
    Update ~}PB&`%7  
    Print "DONE!" \= =rdW-  
     tWT@%(2~0  
End Sub -ich N/U]s  
CWHTDao  
如果屈光度是4，光瞳直径是4，则会输出如下数据： r< sx On  
}y;s(4  
Accommodation = 4 Diopters 1>|2B&_^  
Pupil Diameter = 4 mm 09HlL=0q  
Set aqueous humor thickness = 2.81 :*k  
Set anterior lens radius = 10.4 and conic constant = -2.375869 t&*X~(Yb!  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 }\?UmuolQ  
Set lens thickness = 3.927 @Ge\odfF:  
Set lens index of refraction = 1.42672 s8Bbet  
Set pupil diameter = 4 tUaDwIu#  
DONE! 5R"iF+p4  
2M1}`H\