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 2021-10-22 09:55

Arizona眼睛模型

简介 WpTC,~-  
ocdXzk`  
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。 fD,#z&  
aEZl ICpU7  
模型 6K`frt  
*ArzXhs[  
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。 kZz;l(?0  
H D=WHT&  
Table 1. AZ眼睛模型的定义
^4s#nf:}  
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. z W+wtYV4  
Cc!n`%qc  
光源 *:\QD 8^  
F<'g6 f  
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。 D#(A?oN  
%#7M~RB[  
'7Te{^<FQ$  
图1. 光源和提示信息使用
 zKT \i  
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。 oWXvkDN   
L0+@{GP?  
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。 >{m>&u;Cc  
`uzRHbJ`  
图2. 字母F光源的设定方法光 ]j1BEO!Bg  
G4g },p!  
图3. 字母F在视网膜上位置点列图
dZnq 96<:|  
视网膜的散射 bE0S) b)  
X-n'?=  
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。 u=ENf1{ $>  
jRgv 8n  
g{<3*,  
图4. 视网膜朗伯散射设定
!_x-aro3<  
注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 BJW;A>@Pj  
]t #,{%h  
2H]&3kM3X  
图5. 视网膜重点采样规格设定
.bpxSU%X  
脚本 t$Qav>D  
`^_.E:f  
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: &,e@pvc3  
Nb B`6@r  
图6. 用户对话框的创建与编辑
DVpqm6$ Q  
图7. 用户对话框编辑器
.5ingB3%  
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。 qPzgGbmD9  
余下的脚本计算与屈光度有关的所有参数。 !sR`]0  
Dj<Vn%d*  
分析 t3bN P K^  
NINyg"g<  
屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 $9hOWti  
Cu/w><h)  
图7. 字母F在视网膜上颜色分析
T_\GvSOI  
脚本代码 ,Zs-<e"  
(a)d7y.oo  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. h?$4\^/  
N2~DxVJ5cT  
Dim entity As T_ENTITY 8c~b7F \  
Dim op As T_OPERATION M4')gG;  
Dim mat As T_MODELMATERIAL Bd\p!f<  
Dim A As Double sq :ff  
Dim pupilDiam As Double S{ *RF)  
Dim eID As Long u1>|2D  
Dim parID As Long meIY00   
Dim count As Integer eqjl$QWPJS  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double wcV~z:&^5  
Dim tlens As Double, nlens As Double z?E:s.4F  
Dim curv As Double, conic As Double ]2Lwd@  
Dim ok As Long &|gn%<^  
wAy;ZNu  
Sub Main \9D '7/$I,  
gv<9XYByt  
    '用户输入对话框 f#mY44:,C  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vsES`  
        TextBox 220,21,40,21,.TextBox1 'default: 0 <L5[#V_  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Fdvex$r&  
        OKButton 40,91,90,21 <\yM{ V\  
        CancelButton 190,91,90,21 8HTV"60hTs  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 w"A'uFXLc  
        TextBox 220,49,40,21,.TextBox2 'default: 4 k*lrE4::a  
    End Dialog (u$Q  
    Dim dlg As UserDialog IURi90Ir  
% ]  
    ok = Dialog (dlg) ZRcY; ?  
#PtV=Ee1  
    If ok=0 Then    'cancel button was pressed 6AzH'H F  
        Print "Execution cancelled." rEZa%)XJ  
        End l} h<2  
    End If RCgs3JIE+2  
*S{%+1F  
    'Assign accommodation and pupil diameter & use defaults if field left empty ;XGG&M%3  
    If dlg.TextBox1 = "" Then )2FS9h.t  
        A = 0           'Default accommodation 9h~>7VeZ)  
    Else Ku&0bXP  
        A = CDbl(dlg.TextBox1) UyIjM;X  
    End If 3!ulBiMh  
_RjM .  
    If dlg.TextBox2 = "" Then eGnc6)x@C  
        pupilDiam = 4   'Default pupil diameter cH"M8gP#  
    Else ly6?jVJ  
        pupilDiam = CDbl(dlg.TextBox2) ,R*ru*  
    End If rWSw1(sAA  
U2+CL)al^  
    Print " " [)9bR1wh  
    Print "Accommodation = " & A & " Diopters" xae}8E   
    Print "Pupil Diameter = " & pupilDiam & " mm" Yc\;`C  
l=bB,7gL  
    ' Calculate new parameters with accommodation 1>l {c  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness blxH`O!  
!]5F2~"v  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Bz!ddAvlK  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens #p*OLQ3~  
'{U56^b]  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens N.BD]_C  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a<c %Xy/  
qFf'RgUtP  
    tlens = 3.767 + 0.04*A                  'Lens thickness USe"1(|E  
Y@RPQPmIQ  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction D='/-3f!F]  
RH>b,  
    'Adjust parameters to account for accommodation c9i CH~  
IN`05Q  
    '************************************************************************* l0[jepmpiT  
    'Aqueous thickness (Position of Lens) WynHcxC  
    '************************************************************************* .U9NQwd  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Vx-H W;,  
    GetCustomElement eID, entity QoI@/ jLj  
I+8m1 *  
    parID = FindFullName( "Geometry.Arizona Eye" ) ,GZ(>|  
56&s'  
    ' Delete any shift(s) in z _W tSZmW?  
    count = 0 >0:h(,?V  
    While GetOperationCount(eID)>count =F8uuYX%m  
        GetOperation eID, count, op (/Z~0hA[Q  
        If op.Type="ShiftZ" Then L=4?vs  
            DeleteOperation eID,count "uqa~R{  
            count=count-1 6+m)   
        End If #y}@FG  
        count=count+1 /]<0`nI.  
    Wend y.w/7iw:  
M _$pqVm  
    'Set new shift in ~>xn9vb=  
    op.Type = "ShiftZ" rm(<?w%'?  
    op.val1 = taq ?i)-K?4Sb  
    op.parent = parID IS]03_uQ  
    AddOperation eID, op XC0G5rtB  
    Print "Set aqueous humor thickness = " & taq-0.55 W[j =!o  
26.iFt/:  
    '************************************************************************* htlsU*x  
    'Radius and conic constant of anterior lens BAg*zYV7  
    '************************************************************************* }B^s!y&b  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &g.w~KWa  
    GetConic eID, entity, curv, conic E=sBcb/v  
4 lJ@qhV  
    SetConic eID, entity, 1/Rant, CCant 9%kY8#%SV  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant B;hc|v{(  
-(Taj[;[  
    '************************************************************************* xgsD<3  
    'Radius and conic constant of posterior lens ~}z p}Pt  
    '************************************************************************* 2,q^O3F  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 1}KNzMHk9  
    GetConic eID, entity, curv, conic `S{< $:D  
"{qhk{  
    SetConic eID, entity, 1/Rpost, CCpost ^?&Jq_oU  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost )|uPCZdLZ  
dGP*bMCT  
    '************************************************************************* 4U C/pGZY  
    'Lens thickness (Position of posterior lens surface) \qV5mD]"M  
    '************************************************************************* HBo^8wN  
'1=/G7g  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4#;rv$ {  
IP&En8W+  
    ' Delete any z-shift(s) CHN!o9f  
    count = 0 V|#B=W  
    While GetOperationCount(eID)>count (RWZ [-;)  
        GetOperation eID, count, op =lr*zeHLC  
        If op.Type="ShiftZ" Then NT= ?@uxD  
            DeleteOperation eID,count 5#$E4k:YV  
            count=count-1 [$8*(d"F'  
        End If ElqHZ$a?  
        count=count+1 |>jlY|  
    Wend Ud`V"X  
<)?H98S  
    'Set new z-shift ?n\~&n'C  
    op.Type = "ShiftZ" ~k|~Q\   
    op.val1 = tlens aE1h0`OT  
    op.parent = parID s3/->1#i  
    AddOperation eID, op QRgWzaI  
    Print "Set lens thickness = " & tlens onG,N1`+  
:NA cad  
    '************************************************************************* k[A=:H1"  
    'Lens index of refraction K34ca-~  
    '************************************************************************* im*QaO%a4  
    eID = FindMaterial( "Lens" ) i ,4  
    GetModelMaterial eID, mat }Jh!B|  
+qD4`aI   
    mat.Nd = nlens A6q,"BS^d  
    SetModelMaterial eID, mat zu*0uL  
    Print "Set lens index of refraction = " & nlens r_FW)Fu^  
*)L%pH>`  
    '************************************************************************* RTHdL  
    'Pupil diameter vyN =X]p  
    '************************************************************************* !i.`m-J*  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) @>(l}5U5  
[~f%z(vI  
    'Adjust pupil diameter (trimming volume inner hole) s/`4]B;2U  
O 4l[4,`  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" xO"5bj  
EOVHTDkKf  
    ' Adjust pupil location to just in front of the lens $T1 D ?X  
    parID = FindFullName( "Geometry.Arizona Eye" ) ;vQ7[Pv.j  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) B%^B_s  
    count = 0 frc>0\  
    While GetOperationCount(eID)>count JQQD~J1)E  
        GetOperation eID, count, op :pDwg d  
        If op.Type="ShiftZ" Then |+x;18  
            DeleteOperation eID,count u2-%~Rlo  
            count=count-1 '`/1?,=  
        End If /D 2v 1  
        count=count+1 76zi)f1f  
    Wend OHp 121  
    op.Type = "ShiftZ" `"A\8)6-  
    op.val1 = taq-0.01 '#u |RsZ  
    op.parent = parID ~Jmn?9 3  
    AddOperation eID, op /_ o1b_1 U  
r}D`15IHJ  
    Print "Set pupil diameter = " & pupilDiam } Yj ic4?  
SobK<6  
    'Update AZ Eye subassembly Description d[-w&[iy  
    eID = FindFullName( "Geometry.Arizona Eye" ) Eq~&d.j  
    GetEntity eID, entity 4q~+K' Z  
    entity.Description = "Accommodation = " & A & "D" gPQ2i])"Q  
    SetEntity eID, entity ~?[%uGI0h  
Q4CxtY  
    Update FyZw='D  
    Print "DONE!" :E@"4O?<Y)  
     HWVWl~FA  
End Sub (`!?p ^>A  
IUbYw~f3  
如果屈光度是4,光瞳直径是4,则会输出如下数据: lwQI 9U[O2  
$N+a4  
Accommodation = 4 Diopters t}_qtO7>  
Pupil Diameter = 4 mm KosAc'/ M  
Set aqueous humor thickness = 2.81 l)a]V]oQ  
Set anterior lens radius = 10.4 and conic constant = -2.375869 .OX.z~":y  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 gqyQ Zew  
Set lens thickness = 3.927 7=Ew[MOmM  
Set lens index of refraction = 1.42672 % 89f<F\V  
Set pupil diameter = 4 7evE;KL  
DONE! r,L#JR w#-  
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