[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 zuw6YY8kQ  
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。 KMa?2cJH#  
cqDnZ`|6  
模型 IV76#jL  
"\ m
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。 ryPzq}#  
$v,_8{ !  
QMP:}  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. %-D2I  
R4?/7  
光源 7-)KTBFL  
MeC@+@C  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 udMq>s;  
TD<.:ul]  
<#sK~G  
I~,*Rgv/Z  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 P$Nwf,d2u  
V0>,Kxk  
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。 4?`7XJ0a  
q-'zZ#  
raCxHY  
{8
eNQ-4I  
视网膜的散射 %VgR *  
74_ji!  
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。 gO29:L[t  
9"[#\TW9Vb  
YvonZ  
]*).3<Lw  
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。 lq7
4Fz&(  
o}BaZ|iZ2  
WE\V<MGS/  
+NQw^!0qy  
脚本 rRxqV?>n!  
,xGkE7=5  
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： ?(Nls.c  
:7'anj  
HQ"D>hsuU  
7+fFKZFKF  
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。 |2Q;SaI^\  
余下的脚本计算与屈光度有关的所有参数。 MOXDR  
,Ao8QN  
分析 @AJt/wPk  
<Fi/!  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 K:mb$YJ&  
{=TD^>?  
<3'r&ks  
脚本代码 JVRK\A|R  
6 LC*X  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. [!"u&iu`  
qvCl mZ  
Dim entity As T_ENTITY M*nfWQ a  
Dim op As T_OPERATION Zx@{nVoYe~  
Dim mat As T_MODELMATERIAL fN@2 B  
Dim A As Double ds`a6>746  
Dim pupilDiam As Double e(cctC|l  
Dim eID As Long L0}"H .  
Dim parID As Long WL<Cj_N_{H  
Dim count As Integer I_4'9  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^b'[81%  
Dim tlens As Double, nlens As Double -rUn4a  
Dim curv As Double, conic As Double _jp8;M~Z  
Dim ok As Long uGOvZO^v  
YoJN.],gf  
Sub Main &q>=6sQvf  
BDpeA
F8z  
    '用户输入对话框 V1M oW;&  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 |dK_^~;o  
        TextBox 220,21,40,21,.TextBox1 'default: 0 !ce:S!P  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 n>{>3?  
        OKButton 40,91,90,21 SBs_rhe  
        CancelButton 190,91,90,21 '~2;WF0h  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 w[t!?(![>  
        TextBox 220,49,40,21,.TextBox2 'default: 4 p "u5wJ_  
    End Dialog A~u-Iv(U  
    Dim dlg As UserDialog G}d@^9FkE  
bmFnsqo  
    ok = Dialog (dlg) vk&C'&uV9@  
|,|b~>  
    If ok=0 Then    'cancel button was pressed zGF_c9X  
        Print "Execution cancelled." wj/OYnMw  
        End ?Jio9Zr  
    End If Q u{#4qToA  
qhc3 oRe  
    'Assign accommodation and pupil diameter & use defaults if field left empty 5#~u U  
    If dlg.TextBox1 = "" Then ;CD@RP{$n  
        A = 0           'Default accommodation |}t[-a  
    Else Srg
`
Tt]  
        A = CDbl(dlg.TextBox1) X0O@,  
    End If 8V?O=3<a  
s${ew.eW  
    If dlg.TextBox2 = "" Then X2v|O3>/N  
        pupilDiam = 4   'Default pupil diameter ^h1EE=E"  
    Else Hn+w1v&3  
        pupilDiam = CDbl(dlg.TextBox2) @|sDb?J  
    End If uDbz`VpK  
N;Wm{~Zhb  
    Print " " /z9oPIJ=*  
    Print "Accommodation = " & A & " Diopters" _gxI=EYi  
    Print "Pupil Diameter = " & pupilDiam & " mm" ?VmEbl
 
A@^Y2:pY  
    ' Calculate new parameters with accommodation x8+W9i0[1  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness V*U{q%p(  
eTw sh]  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens kWZ?86!  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 0rP`BK|  
Sxa+"0d6  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens  !*5vXN  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens S3l$\X;6X  
Hx5t![g2K!  
    tlens = 3.767 + 0.04*A                  'Lens thickness ;H}XW=vO  
=^#^Mq)  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 3Uw}!>`%  
C7:;<<"P  
    'Adjust parameters to account for accommodation VPBlU
 
9x$Kb7'F  
    '************************************************************************* 4EQ-48h17  
    'Aqueous thickness (Position of Lens) @ W[LA<  
    '************************************************************************* '[V}]Z>-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ]n _OQ)VO
 
    GetCustomElement eID, entity ruiAEC<Ej  
$ReoIU^<  
    parID = FindFullName( "Geometry.Arizona Eye" ) HE6kt6  
d)d\h`=Z  
    ' Delete any shift(s) in z w eu3c`-a  
    count = 0 3z5w}qN]M  
    While GetOperationCount(eID)>count vy&q7EX<i  
        GetOperation eID, count, op [Tmpj9!q  
        If op.Type="ShiftZ" Then &Cv0oi&B  
            DeleteOperation eID,count rRgP/E#_  
            count=count-1 C^2J<  
        End If 7S'3U}Y>VX  
        count=count+1 8Evon&G59  
    Wend ]w*w@:Zk  

w&VMb&<  
    'Set new shift in ti%uyXfja  
    op.Type = "ShiftZ" ,z8<[Q-#  
    op.val1 = taq ]A.:8;  
    op.parent = parID 33/aYy  
    AddOperation eID, op SY&)?~C  
    Print "Set aqueous humor thickness = " & taq-0.55 ,j^z];  
u^5X@.  
    '************************************************************************* fiG/"/u  
    'Radius and conic constant of anterior lens p)'.swpJ  
    '************************************************************************* Y367Jr@^N  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) H! IL5@@K  
    GetConic eID, entity, curv, conic vuP.V#  
ZoFQJJK56B  
    SetConic eID, entity, 1/Rant, CCant ~Q4 emgBD  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant VkKq<`t<  
mV\QZfoF  
    '************************************************************************* #*r u*  
    'Radius and conic constant of posterior lens c^Y&4=>T  
    '************************************************************************* g3*" ^C2=  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) dG{D2~#  
    GetConic eID, entity, curv, conic  0C3s  
T8*<  
    SetConic eID, entity, 1/Rpost, CCpost ;ndsq[k>  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost pyvZ[R9  
^#:F8D  
    '************************************************************************* =~7%R.U([e  
    'Lens thickness (Position of posterior lens surface) @t W;(8-  
    '************************************************************************* KB3zQJY  
AL(YQ)-Cg  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) KaRdO  
{Vg8pt  
    ' Delete any z-shift(s) lL6bIjf  
    count = 0 r@j$$Pk`  
    While GetOperationCount(eID)>count n4*
hQi+d  
        GetOperation eID, count, op P8Nzz(JF  
        If op.Type="ShiftZ" Then 8V]oR3'  
            DeleteOperation eID,count {i}z|'!  
            count=count-1 <X
5'uve  
        End If : 5=E>!  
        count=count+1 zQ[g*  
    Wend @%8Xa7+  
Mwm=r//  
    'Set new z-shift 4s{_(gy  
    op.Type = "ShiftZ" ^g[,}t:/d  
    op.val1 = tlens f(Hh(  
    op.parent = parID EqY e.dF,  
    AddOperation eID, op }
digw(  
    Print "Set lens thickness = " & tlens &PfCY{_  

+W=  
    '************************************************************************* *TacVp  
    'Lens index of refraction hX?rIx  
    '************************************************************************* ?k6PH"M  
    eID = FindMaterial( "Lens" ) BC/oh+FW3  
    GetModelMaterial eID, mat ;THb6Jz/+  
J?Y1G<&  
    mat.Nd = nlens \M@9#bd  
    SetModelMaterial eID, mat 8(GH.)I+0  
    Print "Set lens index of refraction = " & nlens h}vzZZ2,  
st8=1}:&\  
    '************************************************************************* q(N2#
di  
    'Pupil diameter cy0 %tsB|  
    '************************************************************************* Sk*-B@!S  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) QH_0U`3  
R`7v3{  
    'Adjust pupil diameter (trimming volume inner hole) )+
'
De  
j_r?4k
 
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" vY+{zGF  
0zSRk]i.f  
    ' Adjust pupil location to just in front of the lens .I6:iB  
    parID = FindFullName( "Geometry.Arizona Eye" ) $]&0`F  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) )p,uZ`~
v  
    count = 0 ]e*Zx;6oi  
    While GetOperationCount(eID)>count .Pp;%  
        GetOperation eID, count, op \,U#^Vr  
        If op.Type="ShiftZ" Then /zB;1%m-  
            DeleteOperation eID,count pHW Qk z(  
            count=count-1 Q}a, f75  
        End If aD2+9?m  
        count=count+1 )X8?m <cG  
    Wend Rnl 4  
    op.Type = "ShiftZ" pt"yJtM'P  
    op.val1 = taq-0.01 50s)5G#  
    op.parent = parID WYHr'xJ  
    AddOperation eID, op lq4vX^S  
{l/]+8G^  
    Print "Set pupil diameter = " & pupilDiam eSV_.uvsb  
$On  
    'Update AZ Eye subassembly Description c5>'1L  
    eID = FindFullName( "Geometry.Arizona Eye" ) ^8_`
IT  
    GetEntity eID, entity KNR_upO8  
    entity.Description = "Accommodation = " & A & "D" 6mawcK:7  
    SetEntity eID, entity >DHpD?Pm!  
3f 1@<7*  
    Update IaxzkX_48  
    Print "DONE!" 'rT@r:6fn  
     2TR l@  
End Sub HA +EuQE"  
Dv7/eRt  
如果屈光度是4，光瞳直径是4，则会输出如下数据： pq \M;&  
Dy>U=(S  
Accommodation = 4 Diopters 3 cd5g  
Pupil Diameter = 4 mm Jk
$XL<t  
Set aqueous humor thickness = 2.81 .Yl*kG6r  
Set anterior lens radius = 10.4 and conic constant = -2.375869 l\vvM>#S  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 oXCZpS  
Set lens thickness = 3.927 =r<0l=  
Set lens index of refraction = 1.42672 'IaI7on  
Set pupil diameter = 4 9*?H/iN@p?  
DONE! *`}4]OGv.  
:+1S+w