Accessing Alpha and Beta values in LibMuse (Android)


#1

Hi Everyone,

I am working on a project that requires Alpha and Beta values in real-time on an android device. Currently, I am recording the headset data on MuseLab, converting the .muse file to a csv, and then analyzing the alpha and beta values afterwards.

[B]Is there a way for me to directly get Alpha and Beta values from the headset to an Android device, preferably using LibMuse, without performing any signal processing?[/B]

Thanks in advance!
Jake

EDIT: Looking at the example code I noticed this:


[B]public void [/B]receiveMuseDataPacket(MuseDataPacket p) {
[B]     switch [/B](p.getPacketType()) {
[B]          case [/B][B][I]EEG[/I][/B]:            
               updateEeg(p.getValues()); 
[B]               break[/B]; 
[B]          case [/B][B][I]ACCELEROMETER[/I][/B]:
               updateAccelerometer(p.getValues()); 
[B]               break[/B]; 
[B]          case [/B][B][I]ALPHA_RELATIVE[/I][/B]:            
               updateAlphaRelative(p.getValues()); 
[B]               break[/B]; 
[B]          case [/B][B][I]BATTERY[/I][/B]:            
[B]               fileWriter[/B].addDataPacket(1, p); [I]// It's library client responsibility to flush the buffer, [/I][I]            // otherwise you may get memory overflow.  [/I]
[B]               if [/B]([B]fileWriter[/B].getBufferedMessagesSize() > 8096)                
[B]                     fileWriter[/B].flush(); 
[B]               break[/B]; 
[B]         default[/B]:            
[B]                break[/B]; } } 

Would I just add a case for ALPHA_ABSOLUTE and BETA_ABSOLUTE and then create updateAlphaAbsolute and updateBetaAbsolute functions similar to the updateAlphaRelative function to take the data and record it?


#2

That is what my app does :wink: https://play.google.com/store/apps/d…ns.museMonitor


#3

Could you elaborate on how your app is determining brain wave levels? The reason I ask is because I’m frequently seeing high delta waves while awake (~57dB on average) and I want to know how reliable the information your app is giving me is.


#4

All the brain wave values shown in my app are pulled directly from the Muse using the Interaxon SDK. I do not do any post processing on the values, so accuracy will entirely depend on correct headband placement and of-course the accuracy of the device itself.


#5

Hey wildcolin,

Lower frequencies in EEG usually contain more power. For more info, see my answer to a previous post (http://forum.choosemuse.com/forum/developer-forum/4160-help-needed-with-clarifications-about-bands-and-muselab):

Regarding your Delta power looking similar to your Beta, that is not unusual. To understand why this is, you might want to look into “1/f noise” as it relates to EEG. Basically, the power in the spectrum of an EEG recording decreases with frequency in a 1/f fashion. This is actually intrinsic to many physical processes, EEG being one of them. The Delta, Alpha, Beta oscillations tend to appear as local peaks superimposed on a downward-sloping 1/f type curve. So more power is almost always contained in lower frequencies than in higher frequencies. Analyzing different EEG frequency bands is more about comparing how their power changes with time rather than just looking at their instantaneous values. For this reason, we provide “session scores” for each frequency band: https://sites.google.com/a/interaxon…Session-Scores


#6

That doesn’t make sense. There are no OSC DSP paths that give a single value for any of the brain waves. There are always four channels for each type of brain wave. That would suggest that your app is averaging them. That is what I want to know.


#7

Heh, I get the impression I won’t be the last person to ask this question. Thanks for the informative reply.


#8

Yes, sorry. I think perhaps you forgot to look at the setting screen! :wink: Average is the default setting, but you can also display each individually.


#9

Hi,I have the Muse 2016,after recording the data in csv file from Muse monitor,there is any free software to open and analyze the file?I can only find very complex softwares that require hours just to setting…thanks


#10

You can view your Muse Monitor recordings online here http://MuseMonitor.com/Chart.php


#11

hi @Enigma644 , so your app uses the ALPHA_SCORE , ALPHA_RELATIVE or ALPHA_ABSOLUTE
I’m confused,
I’m not getting the ALPHA _SCORE at all?
What does the Muse App uses?


#12

Muse Monitor uses (and records) the Absolute value, as this is the actual data and all other values can be derived from it.

Relative is the single absolute value divided by the sum of all absolute values.

Score is just a rolling average mapped to a [0:1] scale.

Details of these are here: http://developer.choosemuse.com/tools/available-data