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How to get EEG, Alpha waves from BioWave1.1?

Posted: Mon Feb 11, 2008 2:18 pm
by mtuters
I am trying to work out how to gett EEG data out of the BioWave1.1.

Specifically, I'm trying to figure out how to get Alpha waves as shown in the pdf that accompanies the product.

Mounting the 3 sensors at the back of the head, I'm using the MAX and, so long as the sensors are mounted lower down the neck and i moisten my hair, I get some kind of data, but I'm encountering difficulty in seeing much of pattern in that data that corresponds with alpha activity.

In an attempt to stimulate the production of alpha, I have of course used eyes open/closed technique, as suggested in the pdf, as well as tried using stroboscopic light patterns (I also am working with binaural beats), so far all this to no avail!

As mentioned I've been slightly dampening the sensors. Might I need to use some kind of conductive gel?

Re: How to get EEG, Alpha waves from BioWave1.1?

Posted: Tue Feb 26, 2008 8:23 pm
by hughlusted
Hi Marc - I have been trying a few alpha experiments with the Biowave, and there are some variables that you should be aware of.

First, it would be useful to know what you are using the alpha signal for. The MAX patch is not ideal for detecting alpha. An alpha burst generally has larger amplitude than the background beta activity and this is all the MAX patch can display - an amplitude difference. Also, the display does not show the actual EEG waveform. You might consider using audio software (such as Audacity) to view the data from the Biowave.

I’m mentioning the data display because that may be your difficulty in seeing your alpha waves. Some people have very small amplitude alpha activity – even when measured from the back of the head – and it may not show up using the MAX patch.

Let’s go back to the headband – to be sure you are using it correctly. Put the headband on as though you were wearing the electrodes on your forehead – only rotate it so the 3 electrodes are on the back of your head. Position the 3 so that the middle one is centered on the back of your head. Also make sure the band is fitting snuggly, and don’t let the electrodes slip down toward your neck. Now, using a little squeeze bottle (like an eye drops bottle) drip some tap water in the hair under each electrode. Use enough water that you can feel it on your scalp. If you have really thick hair, you may have to tighten the headband to compress the hair against the scalp. The idea is that you want to create a conductive bridge between the scalp and the electrode.

Using the headband with the MAX patch you need to tune the min and max sliders to optimize the signal display. As mentioned in the user guide, most people produce a burst of alpha by closing the eyes. So try closing your eyes for 2 - 3 seconds a few times with the patch running and see if you can see the 10 Hz alpha burst pop up above the background EEG.

As a next step – tell us what your alpha application is and maybe we can find a better software solution for you.

Re: How to get EEG, Alpha waves from BioWave1.1?

Posted: Tue Feb 26, 2008 9:41 pm
by mtuters
the screengrab below shows what MAX shows me when i wear the headband as you instructed. if i move it closer to the kneck as you tell me not to do i get more interesting data. i understand that MAX may not be the final solution for the fine grained data i'm looking for, however, why would it give me absolutely nothing, that seems odd, no?

Re: How to get EEG, Alpha waves from BioWave1.1?

Posted: Tue Feb 26, 2008 9:49 pm
by mtuters
here's something odd, after keeping the sensor on my head for 10 minutes (i had wet it at the beginning and got a flatline as the previous post illustrates), quite suddenly, and for no apparent reason, the sensor just kicked int and started to give me something that looks more like eeg data

Re: How to get EEG, Alpha waves from BioWave1.1?

Posted: Tue Feb 26, 2008 10:09 pm
by mtuters
after havingat first placed the sensor on my head as you suggested hugh, and just got 10 minutes of flatline, suddenly i got the sensor to work (don't ask me what happened it just suddenly started to work) i feel like i managed to actually produce alpha, with the help of strobosopic flicker <> and this is what it looks like (the second attached image), compared with just the noisy baseline below. so now, the challenge is if there is enough of a clear difference that i can use some kind of beysian filter, or some such thing, so that i can use only the alpha. i have to be careful, cause there's a lot of random fluctuation from just moving the ears, or even moving the head at the neck.

Re: How to get EEG, Alpha waves from BioWave1.1?

Posted: Mon Mar 03, 2008 12:47 pm
by mtuters
so as the post above shows, i managed to get what looks like alpha waves out of the sensor, hooray!
while that can be seen as a minour success it also brings up more issues: for 1.) one i had from some technical difficulties getting the thing to work at all, 2.) second, i have found it hard to repeat the results apart from that one success, and 3.) third assuming i solve the first two, there seems to be tons of what i guess is just is just plain old background noise in the data, that i need to filter out. so i guess that i need to do some real time signal processing to get anything useful out of the sensor (just making a digital switch that tells me when i'm producing alpha would be a start, although i'd rather be able to get some more data than that ultimately). i know this problem is a touch one, but that's where i'm at, and any advise would be most appreciated.

Re: How to get EEG, Alpha waves from BioWave1.1?

Posted: Tue Mar 04, 2008 2:23 pm
by mtuters
Hugh, in order to help with advise on how best to use the sensor, you asked for information on the piece I am trying to produce for which the BioWave is the data acquisition device, so what follows is a project description:

What I have in mind is a screen based real-time art installation in which the "participant" enters a gallery space and an attendant fits the "participant" with a head-mount (embedded with the BioWave), instructing them on the experience, and adjusting the sensors output to the individual. A delicate process this may take 5-10 minutes. Following said "tuning", the trainee will begin to experience a combination of aural stimulation and visual deprivation. Since as the BioWave's PDF states Alpha is the easiest to acquire, at this point, conceptually, the project is based around stimulating the production of Alpha.

The head-mount is additionally embedded with noise canceling headphones playing a binaural frequency which stimulate the creation of the brain's Alpha. The "participant's" eyes are covered so that there is no direct visual information to process, such circumstances are ideal for the detection of Alpha waves. When Alpha is detected, the image on screen produces a mild flicker visible through the translucent visor. As their production of Alpha hopefully increases, the system rewards them by increasing the brightness and frequency of the flicker as well as augmenting the binaural beats accordingly.

At first, upon entering the space the image projected on-screen will appear as highly rendered image of a dark pool of water. Once the participant is fitted with the headmount, however, and the data starts coming in, the image changes (all the participant, however, can see at this point is gross changes in luminance of the on-screen image). As the participant starts to produce Alpha this data is fed-back into the visualization to control a number of the images parameters. For one thing, the image on screen starts flashing (this can be seen by the participant through the translucent visor), and the binaural beats become augmented. These stimuli are intended to relax the participant and encourage the production of more Alpha.

From the point of view of the surrounding audience (i.e. not the participant) the experience however is different. As they would be able to see the screen unimpeded, they would see a 3d computer graphic image appear on-screen. (For aesthetic reasons related to positioning the project in relation to the history of biofeedback and virtual reality research, as well as in the contemporary context of interactive entertainment the image that the audience will see is intended to resemble a portal to another dimension.) The audience thus see a clear representation of the shape of the wormhole form on-screen, the data from the participant's brainwaves controlling image parameters including: the shape, direction, texturing and speed of fly-through (additionally peaks in the data could be used to generate particles, that would seem as though they were emanating from the wormhole). Finally there is also the idea what peaks in the data would create loud Bass-heavy white noise on speakers (which the head-mount's headphones would cancel-out).

Here, then, is the crux of the idea, as the helmet wearer creates alpha (representing his state of relaxation) while, the party outside gets more exciting and the visuals get more stimulating, eventually culminating to pure flashing light and very fast BPMs. The irony here, of course, is that while the experience gets more and more intense and aggressive for the outside audience, it relies on the wearer to keep relaxing in order to create more Alpha. In this sense the participant wearing the helmet is like the calm at the center of the virtual storm.

Re: How to get EEG, Alpha waves from BioWave1.1?

Posted: Wed Dec 30, 2009 11:33 pm
by venture
How can I get EEG data from BioWave v1.2?
I could see Alpha waves in Max patch after few minutes (as mtuters wrote).
But Max patch doesn't allow save any data, as I understand.
I-CubeX editor is so complicated, and I don't understand how to receive EEG data with it.

Did anybody have success to get EEG data in file?