首页 -> 登录 -> 注册 -> 回复主题 -> 发表主题
光行天下 -> 讯技光电&黉论教育 -> Arizona眼睛模型 [点此返回论坛查看本帖完整版本] [打印本页]

infotek 2023-04-27 08:29

Arizona眼睛模型

2 4+  
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。 M2|!,2  
^hiY6N &  
模型 9zb1t1[ W  
w8w0:@0(  
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。 h@Ea5x  
Table 1. AZ眼睛模型的定义
CYLab5A  
6{buel(|e  
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. Lo%vG{yTr  
.Pponmy  
光源 @k&6\1/U  
\0x>#ygX  
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。 1oej<67PdJ  
@T~XwJ~  
图1. 光源和提示信息使用
[M[<'+^*  
u"=]cBRWL6  
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。 !i)!|9e  
*,4rYb7I w  
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。 6X*vCylI  
图2. 字母F光源的设定方法光 wn5OgXxG<  
Yi%lWbr  
图3. 字母F在视网膜上位置点列图
K2zln_W  
"-$}GUK?Z  
视网膜的散射 ID2->J  
a]u.Uqyx2w  
在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 .oyAi||  
|${4sUR  
图4. 视网膜朗伯散射设定
P!W%KobZ7|  
22ON=NN  
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。 +PjTT6  
A7Ql%$v7^  
图5. 视网膜重点采样规格设定
=U3S"W %  
G0UaE1n  
脚本 \Nt 5TG_  
E+lR&~mK=  
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: T;92M}\  
图6. 用户对话框的创建与编辑
KVa{;zBwl  
图7. 用户对话框编辑器
yMz#e0k  
PaI\y! f  
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。 }#FV{C]  
余下的脚本计算与屈光度有关的所有参数。 '#f<wf n  
$&as5z8  
分析 |reA`&<q  
tTy!o=  
屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 9r].rzf9  
图7. 字母F在视网膜上颜色分析
r >'tE7W9  
e"t0 rScA  
脚本代码 >[;W ~*  
KEOk%'c,  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. _ p\L,No  
$H@SXx  
Dim entity As T_ENTITY !i;6!w  
Dim op As T_OPERATION ~S/oW89  
Dim mat As T_MODELMATERIAL mH$tG $  
Dim A As Double eTa_RO,x  
Dim pupilDiam As Double ty,oj33  
Dim eID As Long ^/ "}_bR  
Dim parID As Long @ b!]Jw  
Dim count As Integer VvyRZMR  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double kkq1:\pZ]a  
Dim tlens As Double, nlens As Double \jiE :Qt  
Dim curv As Double, conic As Double GOc   
Dim ok As Long INN}xZ  
kEDpF26!  
Sub Main ..} P$  
^O_Z5NbC3  
    '用户输入对话框 oV vA`}  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 +l7)7qKx  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ;bE/(nz M  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 PR@6=[|d  
        OKButton 40,91,90,21 ZM.'W}J{ *  
        CancelButton 190,91,90,21 #d@wjQ0DW  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Ol>q(-ea  
        TextBox 220,49,40,21,.TextBox2 'default: 4 U!(.i1^n  
    End Dialog 5s[nE\oaG  
    Dim dlg As UserDialog (Mk7"FC7  
~m6=s~Vn  
    ok = Dialog (dlg) 1"H;Tr|  
0nb%+],pX  
    If ok=0 Then    'cancel button was pressed pa!BJ]~  
        Print "Execution cancelled." Gm|-[iUTG]  
        End `WayR^9  
    End If bXs=<`>  
uV5uZ  
    'Assign accommodation and pupil diameter & use defaults if field left empty Vf cIR(  
    If dlg.TextBox1 = "" Then 'S_i6K  
        A = 0           'Default accommodation uN`/&_$c  
    Else nJ;^Sz17Q  
        A = CDbl(dlg.TextBox1) |n 26[=\B  
    End If $r!CQ 2S  
IbI0".o  
    If dlg.TextBox2 = "" Then '`2KLO>!  
        pupilDiam = 4   'Default pupil diameter E#J})cPzw  
    Else fu5L)P^T  
        pupilDiam = CDbl(dlg.TextBox2) a:cci?cb  
    End If ?9~^QRLT  
pl]|yIZ  
    Print " " yD3}USw  
    Print "Accommodation = " & A & " Diopters" ME)Tx3d  
    Print "Pupil Diameter = " & pupilDiam & " mm" 1wR[nBg*|  
P6v ANL-B  
    ' Calculate new parameters with accommodation E.K^v/dNdq  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness EOB8|:*  
c~ R'`Q  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [M\ an6h6O  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens hN3FH# YO  
al2lC#Sy  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens & P-8_I  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 0-Mzb{n5  
Q4u.v,sE  
    tlens = 3.767 + 0.04*A                  'Lens thickness {+67<&g  
B\Nbt!Ps  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction r07u6OA  
QEr<(wM-y  
    'Adjust parameters to account for accommodation 4}H+hk8-  
PeJ#9hI~rQ  
    '************************************************************************* hZJ~zx~  
    'Aqueous thickness (Position of Lens) J p?XV<3Z  
    '************************************************************************* m4/qxm"Dx:  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,6>3aD1w~q  
    GetCustomElement eID, entity `p()ko  
u9"=t  
    parID = FindFullName( "Geometry.Arizona Eye" ) ZO<,V  
A6]:BuP;c  
    ' Delete any shift(s) in z &ksuk9M  
    count = 0 >PA*L(Dh%  
    While GetOperationCount(eID)>count wMVUTm  
        GetOperation eID, count, op a}y b~:TC  
        If op.Type="ShiftZ" Then c>LP}PGk  
            DeleteOperation eID,count EVPQe-  
            count=count-1 5MnP6(3$  
        End If <st<oR'  
        count=count+1 G0 )[(s  
    Wend Hhknjx  
R #wZW&N  
    'Set new shift in \ptO4E  
    op.Type = "ShiftZ" CP7Fe{P  
    op.val1 = taq @;4;72@O  
    op.parent = parID 30sJ"hF9  
    AddOperation eID, op V#ELn[k  
    Print "Set aqueous humor thickness = " & taq-0.55 VEgtN}  
JR] 2Ray  
    '************************************************************************* ]yPK}u  
    'Radius and conic constant of anterior lens e4z~   
    '*************************************************************************  FSMM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) `H! (hMMV  
    GetConic eID, entity, curv, conic <odi>!ViH  
tc'iKJ5)  
    SetConic eID, entity, 1/Rant, CCant T1d@=&0"  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant U"r*kO%  
d'';0[W)  
    '************************************************************************* 9Vt ^q%DC  
    'Radius and conic constant of posterior lens G=cRdiy`C  
    '************************************************************************* x {NBhq(4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) .) Ej#mk  
    GetConic eID, entity, curv, conic $4{sP Hi)I  
Ic0Sb7c  
    SetConic eID, entity, 1/Rpost, CCpost %tVU Rj  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost + +L7*1t  
|?88EG@05  
    '************************************************************************* 76w[X=Fv  
    'Lens thickness (Position of posterior lens surface) 2PQBUq  
    '************************************************************************* _x.2&S89  
<W0(!<U  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {bXN[=j  
l!,tssQ  
    ' Delete any z-shift(s) 6:2*<  
    count = 0 <SNr\/aCRi  
    While GetOperationCount(eID)>count 1J!v;Y\\  
        GetOperation eID, count, op Tr?p/9.m  
        If op.Type="ShiftZ" Then toY_1  
            DeleteOperation eID,count 8ae`V!5  
            count=count-1 PlB3"{}0Q  
        End If ZjxF@`H  
        count=count+1 4#(/{6J  
    Wend D|5mNX %e  
#m U\8M,  
    'Set new z-shift i431mpMa  
    op.Type = "ShiftZ" *P' X[z  
    op.val1 = tlens 8]#FvgX  
    op.parent = parID X`g<"Ka  
    AddOperation eID, op v`oilsrc  
    Print "Set lens thickness = " & tlens 8[@,i|kgg0  
$s _k/dM~&  
    '************************************************************************* /H<{p$Wd  
    'Lens index of refraction FsqH:I4O  
    '************************************************************************* Zz} o  t  
    eID = FindMaterial( "Lens" ) r%;|gIky  
    GetModelMaterial eID, mat (A?>U_@  
__}SHU0R  
    mat.Nd = nlens P.YT/  
    SetModelMaterial eID, mat "[ S[vkI  
    Print "Set lens index of refraction = " & nlens Uc!k)o#=  
zYaFbNi  
    '************************************************************************* !mK()#6  
    'Pupil diameter {m U%.5  
    '************************************************************************* W7!Rf7TK  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Py*WHHO  
B*G]Dr)e  
    'Adjust pupil diameter (trimming volume inner hole) b,Eq-Z;  
 8~T}BC  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |r+ x/,2-  
BZ\="N#f  
    ' Adjust pupil location to just in front of the lens wbWC &X.  
    parID = FindFullName( "Geometry.Arizona Eye" ) SXsszb:_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) gbMA-r:IC  
    count = 0 {U-z(0  
    While GetOperationCount(eID)>count ;C-ds  
        GetOperation eID, count, op Ho(M O!(  
        If op.Type="ShiftZ" Then NzZ(N z5  
            DeleteOperation eID,count UG.:D';3,  
            count=count-1 `n6cpX5  
        End If fm Yx  
        count=count+1 tzN9d~JZ  
    Wend ~xG/yPl  
    op.Type = "ShiftZ" n_{&dVE  
    op.val1 = taq-0.01 P:g!~&Q  
    op.parent = parID q2#Ebw %]  
    AddOperation eID, op 9(fh+  
OR&pGoW  
    Print "Set pupil diameter = " & pupilDiam RV@B[:  
(w-"1(  
    'Update AZ Eye subassembly Description "6]oi*_8  
    eID = FindFullName( "Geometry.Arizona Eye" ) ~d&&\EZ  
    GetEntity eID, entity M"]?'TMfXc  
    entity.Description = "Accommodation = " & A & "D" %x#S?GMV<  
    SetEntity eID, entity eLT3b6'"?  
JAHmmNlW  
    Update Q=!QCDO(  
    Print "DONE!" F$>#P7ph\a  
     !=30s;-  
End Sub H.?`90IQ  
Hd4 ~v0eS  
如果屈光度是4,光瞳直径是4,则会输出如下数据: ~7aD#`amU  
CXn?~m&K  
Accommodation = 4 Diopters &=t~_ Dc  
Pupil Diameter = 4 mm yVzV]&k  
Set aqueous humor thickness = 2.81 ;|T|*0vY[  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Kez0Bka  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 R)d_0Ng  
Set lens thickness = 3.927 \>su97  
Set lens index of refraction = 1.42672 #l>r9Z71  
Set pupil diameter = 4 `Zp*?  
DONE!
\Uh/(q7  
=?L16mu1&  

查看本帖完整版本: [-- Arizona眼睛模型 --] [-- top --]

Copyright © 2005-2025 光行天下 蜀ICP备06003254号-1 网站统计