[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 PB53myDQ  
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。 LA%bq_>f  
l! v!hUb+  
模型 !kL> ,O>/  
eV7u*d?  
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。 BqH]-'1G  
`t(D!  
XK ApLz  
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. vq!uD!lr  
&:5\"b  
光源 P"3*lk+w  
<rIz Z'D  
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。 z@Hp,|Vy[  
|Au]1}  
E9}{1A  
z[EFQ^*>  
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。 '+Xlw  
4!#a3=_  
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。 6#e::GD  
831JwSR  
OGO~f;7  
XYEv&-M`?w  
视网膜的散射 TDt
Amk  
hBU\'.x  
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。 E?)656F[  
sJG5/w  
58V[mlW)O0  
9`Q<Yy"du  
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。 kA wNly  
x=Hndx^  
^aZAw%K  
%~xGkk"I  
脚本 3oy~=  
s{bdl[7  
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： ^dm!)4W  
x_#-tB  
\G|%Zw|  
;]sYf  
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。 ;gg\;i}^  
余下的脚本计算与屈光度有关的所有参数。 ?.=}pAub  
&>g'$a<[  
分析 lfZ04M{2  
Z{6kWA3Kk  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 t2HJsMX  
9=X)ung9  
6uPcXd:8ZR  
脚本代码 eY
X5(`c[  
*f%>YxF  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. N_pUv  
Ev"|FTI/  
Dim entity As T_ENTITY {LHR!~d}5f  
Dim op As T_OPERATION <^?1uzxH8A  
Dim mat As T_MODELMATERIAL \!]hU%Un  
Dim A As Double :Y,BdU  
Dim pupilDiam As Double )0 W`  
Dim eID As Long D]G)j  
Dim parID As Long VZ& A%UFC  
Dim count As Integer 7JJ/D4uT  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &fa5laJb  
Dim tlens As Double, nlens As Double J(4"S o_  
Dim curv As Double, conic As Double 'B5^P  
Dim ok As Long |*/[`|*G  
C)'q QvA  
Sub Main {--0z3n>  
Z/;Xl~  
    '用户输入对话框 uDw.|B2ui  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 jHXwOJq %  
        TextBox 220,21,40,21,.TextBox1 'default: 0 1923N]b  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \s"U{N-  
        OKButton 40,91,90,21 'H5M|c$s  
        CancelButton 190,91,90,21 ]?O2:X  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 *Xo]-cKL0  
        TextBox 220,49,40,21,.TextBox2 'default: 4 tZ`Ts}\e  
    End Dialog c~QS9)=E  
    Dim dlg As UserDialog 0:0NXVYs&  
7>iU1zy  
    ok = Dialog (dlg) ;9o;r)9~  
)
^||\G  
    If ok=0 Then    'cancel button was pressed -=s(l.?Hm5  
        Print "Execution cancelled." 5DOBsf8Jo  
        End qd3Q}Lk  
    End If Twn4
lG4~  
=K'cM=WM6  
    'Assign accommodation and pupil diameter & use defaults if field left empty 8 C[/dH  
    If dlg.TextBox1 = "" Then BH]Ynu&o  
        A = 0           'Default accommodation ^7zu<lX  
    Else z#BR5jF  
        A = CDbl(dlg.TextBox1) s,#>m*Rh  
    End If kKC9{^%)  
(=D&A<YX  
    If dlg.TextBox2 = "" Then t!Sq A(-V  
        pupilDiam = 4   'Default pupil diameter lL1k.&|5m  
    Else I>L-1o|^  
        pupilDiam = CDbl(dlg.TextBox2) 8-<:
i  
    End If ifN64`AhRX  
AJ#Nenmj  
    Print " " {*{Ox[Nh{  
    Print "Accommodation = " & A & " Diopters" @(r/dZc  
    Print "Pupil Diameter = " & pupilDiam & " mm" 6aM*:>C"  
)95f*wte  
    ' Calculate new parameters with accommodation @gY)8xMbA  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness PkI:*\R  
dy_:-2S  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens MSf;ZB  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8@so"d2e  
{s.=)0V  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens z5ij(RE]  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens l;o1 d-n]  
%iV^S!e  
    tlens = 3.767 + 0.04*A                  'Lens thickness II6CHjW`;  
A}eOFu`  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction SlsdqP 9  
/SYw;<=  
    'Adjust parameters to account for accommodation $DG?M6  
8WnwQ%;m?  
    '************************************************************************* J2:y6kGj>  
    'Aqueous thickness (Position of Lens) ]U"94S U:)  
    '************************************************************************* vVOh3{e|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7uzkp&+:  
    GetCustomElement eID, entity <[w=TdCPs  
,v"YqD+GC5  
    parID = FindFullName( "Geometry.Arizona Eye" ) iLSr*` o  
m*JaXa  
    ' Delete any shift(s) in z 4?B\O`sy.  
    count = 0 |\pbir  
    While GetOperationCount(eID)>count %c4Hse#Y  
        GetOperation eID, count, op 82l~G;.n3  
        If op.Type="ShiftZ" Then `V##Y  
            DeleteOperation eID,count Bz,?{o6s)Q  
            count=count-1 }_ 9Cxji  
        End If ob8qe,_'  
        count=count+1 h$2</J"  
    Wend I_]^ .o1q  
F w?[lS  
    'Set new shift in e%b6(%  
    op.Type = "ShiftZ" @;"|@!l|  
    op.val1 = taq Yw-G'  
    op.parent = parID <7~'; K  
    AddOperation eID, op Zu7)gf  
    Print "Set aqueous humor thickness = " & taq-0.55 7Op>i,HZk\  
&q9T9AOS  
    '************************************************************************* PUUwv_  
    'Radius and conic constant of anterior lens n@)K #  
    '************************************************************************* ?`?)QE8  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) jnn}V~L  
    GetConic eID, entity, curv, conic \.-bZ$  
Z.Lc>
7o  
    SetConic eID, entity, 1/Rant, CCant {tWf  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant DA\2rLs  
m^zUmrj[  
    '************************************************************************* K|epPGRr  
    'Radius and conic constant of posterior lens `x*Pof!Io  
    '************************************************************************* Fe4(4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 5?x>9Ca  
    GetConic eID, entity, curv, conic g%=z_  
a^I\ /&aw'  
    SetConic eID, entity, 1/Rpost, CCpost #pnI\  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost BI%$c~wS  
{N+$Q'  
    '************************************************************************* JJN.ugT}1  
    'Lens thickness (Position of posterior lens surface) p
;>ec:z3M  
    '************************************************************************* %V7at7>o  
cPlZXf  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'DCTc&J['  
3ca (i/c  
    ' Delete any z-shift(s) 5j?3a1l0  
    count = 0 _z|65H  
    While GetOperationCount(eID)>count >G25m'&,7  
        GetOperation eID, count, op gi1^3R[  
        If op.Type="ShiftZ" Then gtppv6<Mj4  
            DeleteOperation eID,count <eWf<  
            count=count-1 `r9!zffyS  
        End If I=`U7Bis"  
        count=count+1 (5-FVp fb  
    Wend g,!L$,/F  
S4_YT@VD%  
    'Set new z-shift vg32y /l]S  
    op.Type = "ShiftZ" X}Ai-D  
    op.val1 = tlens [M=7M}f;  
    op.parent = parID W')Yg5T  
    AddOperation eID, op n-tgX?1'  
    Print "Set lens thickness = " & tlens +V{kb<P  
9y"@(  
    '************************************************************************* -lY6|79bF  
    'Lens index of refraction +~ P2C6@G  
    '************************************************************************* vdc\R?  
    eID = FindMaterial( "Lens" ) hcsP2 0s  
    GetModelMaterial eID, mat rlOAo`hd  
B|C2lu  
    mat.Nd = nlens _@ qjV~%Sy  
    SetModelMaterial eID, mat ~:s>aQ`!  
    Print "Set lens index of refraction = " & nlens 52Z2]T c,  
w;4<h8Wn5  
    '************************************************************************* <L8'!q}  
    'Pupil diameter mn"G_I  
    '************************************************************************* ;n*.W|Uph  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) EE06h-ns  
#A JDWelD  
    'Adjust pupil diameter (trimming volume inner hole) Kqb#_hm  
f<d`B]$(  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" {k TEHe  
.ypL=~Rp  
    ' Adjust pupil location to just in front of the lens ^BikV  
    parID = FindFullName( "Geometry.Arizona Eye" ) dy%;W%   
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) z!ZtzD]cb  
    count = 0 -b9\=U[  
    While GetOperationCount(eID)>count <KL,G};0pm  
        GetOperation eID, count, op |4;Fd9q^m  
        If op.Type="ShiftZ" Then  M^=zt  
            DeleteOperation eID,count ) j#`r/  
            count=count-1 P~>OS5^  
        End If *v^Jb/E315  
        count=count+1 |"8b_Cq{  
    Wend d;Ym=YHJtn  
    op.Type = "ShiftZ" un mJbY;t  
    op.val1 = taq-0.01 6 $4[gcL'  
    op.parent = parID '}53f2%gKa  
    AddOperation eID, op M=@:ZQ^!  
NX*Q F+  
    Print "Set pupil diameter = " & pupilDiam BU/"rv"(Fg  
uP)'F
I  
    'Update AZ Eye subassembly Description pZ.ecZe/  
    eID = FindFullName( "Geometry.Arizona Eye" ) > PRFWO  
    GetEntity eID, entity V1N3iI  
    entity.Description = "Accommodation = " & A & "D" vxBgGl  
    SetEntity eID, entity c<:-T  
xX&+WR  
    Update _YhES-Ff  
    Print "DONE!" we//|fA<  
     = SMXDaH  
End Sub y@S$^jk.  
%D{6[8  
如果屈光度是4，光瞳直径是4，则会输出如下数据： 'x#~'v
*  
yW=::=  
Accommodation = 4 Diopters zZPO&akB"  
Pupil Diameter = 4 mm J5K^^RUR  
Set aqueous humor thickness = 2.81  ~d.Y&b  
Set anterior lens radius = 10.4 and conic constant = -2.375869 {3mRq"e  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ?=sDM& '  
Set lens thickness = 3.927 S6DKREO  
Set lens index of refraction = 1.42672 L\J;J%fz.  
Set pupil diameter = 4 iHM%iUV  
DONE! D0-3eV-  
zFfr.g;L