Different readings from 2 different Muse 2 headbands

[lightinmyshadow]

Hi James.

I've been recording my brainwaves with Muse 2 for 13 months and graphing my progress over time.

For 13 months my theta and delta waves have been relatively consistent on all 4 sensors.

I brought a new Muse 2 and began using it 31 May 2021. Since then, my right side sensors (AF8 & TP10) have been showing a significant drop in delta and theta waves.

My RAW is clean, and I've done factory resets. It's either my brainwaves OR it's a fault with my new Muse 2.

I guess I'm just asking for your opinion here cause I'm stumped. What do you think the chances are of it being a fault with the Muse - but ONLY affecting the right side sensors, and ONLY affecting the delta and theta brainwave readings?

(sure there is the possibility that it's working just fine and it is, in fact, my brainwaves...)

I'm frustrated because I expect that two different Muse 2 headsets (or 10 for that matter) would be calibrated the same, and ALL capture and relay brainwave information exactly the same. It's really messing with my research.

I've raised this with Interaxon but they say there is nothing wrong with my Muse. They've asked me to ask you - as I'm capturing this information with Mind Monitor software. Have you seen this before? Any help would be appreciated.

I've attached images of my progress graphs since May 2020 - you can see on AF8 & TP10 what I'm referring to....this decrease does not happen on AF7 and TP9 - my left side. Looking forward to your response.

[James]

Assuming that these graphs are showing the daily averages of your meditations over a year and you've not made any other changes,(other than swapping out the Muse), then I'd agree with you that the two devices are producing different results.

So now the question is, why.

On both graphs (mainly TP10), you're seeing a drop in Delta and some Theta. I think that the most likely cause for this is that the new Muse 2 has clean sensors.
Poor sensor contact (and EMG) manifest as Delta and to a less extent Theta. So that would explain what we're seeing here.

Do you still have the other Muse? If so I would try scrubbing the sensors with an old toothbrush and rubbing alcohol and you will likely get similar readings. Note that oxidization/dirt on the sensor pads might not be very visible and I've heard that most people who had high Delta problems from dirty sensor pads needed to scrub them much more vigorously than they thought they'd need to before the problem was fixed!

The only way to really test the true calibration of the sensors, is to hook them up to a signal generator and record the RAW EEG.

The other possibility is that the two Muse's have different metal types on the contacts and that's producing slightly different results. I vaguely recall someone telling me that the sensor pad metal was a different colour on a Muse that they purchased later, vs the one they got on launch day. So that's something you could check if you still have the old one.

[lightinmyshadow]

Thanks James,

Yes these graphs show the averages over the year, and no other changes were made - except for switching to the new Muse on 31 May....

I still have my old Muse 2, and the metal sensors LOOK the same....but I can't test it out as it broke (hence getting the new Muse). So the old Muse is useless.

I hear you about the old Muse possibly accumulating dirt/oil etc giving higher delta readings - it makes total sense, but it's not that - I regularly and vigorously cleaned the sensors of my old Muse with alcohol wipes and water - plus if you look at the beginning of the graphs, at that time my old Muse was fresh out of the box clean, and the delta/theta output never really changed from then on.

I've also attached my LEFT side sensor images - which show no issues at all with my new Muse 2. It's only the RIGHT side that has the problem. I believe it's the new Muse with the issue - as these new delta and theta values have dropped abnormally low (especially compared to the left side).

I'm stumped (and annoyed haha!) I'm trying to get Interaxon to exchange it, failing that, I'll bite the bullet and buy ANOTHER Muse 2, test and compare the results. If the 3rd Muse shows the same results, then it's my brain (lol) - and I'll send the 3rd Muse back for a change of mind refund. If the 3rd Muse shows my old theta/delta levels and I'm going to bug them to check the calibration of my current one as there's definitely a fault.

I love a good mystery, but I'm over this one! I simply want the device to work as it should. If you have any further thoughts, please do let me know, otherwise, as always thank you for your input - it's been very much appreciated

[James]

I wouldn't exchange it. This new Muse is giving you better results! You want low Delta while awake.

Do you have the original CSV recordings for each of these? If so, can you email (Support@Mind-Monitor.com) me 20/06/21 and one with the old Muse, say 18/09/20.

What broke on the old Muse? I might be able to fix it. Email me photos.

Also, not important for this, but I noticed in the date sequence you have have a few Jan 2020 dates on the far right in between Jan 2021 dates.

[lightinmyshadow]

I do have the CSV files, I'll email them over now.

The way my old Muse broke, was 13 months in TP9 stopped connecting (both to Mind Monitor and Muse app) it just flat-lined. I tried everything - cleaning super vigorously, hard resets, 'forgetting the device' on bluetooth, reconnecting on an iphone AND android - nothing worked. Interaxon saw photos of the horseshoe not picking up TP9 and the flat-lined signal and also agreed it died.

I tried it again the other day and it's gotten worse. Now connection on all 4 sensors drops out continuously, around every 5 seconds. Bluetooth connection I guess - and I'd be happy to email you photos, but I don't know if you could help me fix that! (please tell me if you can....)

Something I should have mentioned earlier regarding my delta waves, is that my meditation is eyes open. (It's mindful drawing in a way where I'm reprogramming myself - it's weird and it works I barely blink (not really noticeable on the RAW), i don't make 'eye movements', no muscles, jaw clenches - BUT yes my eyes are open.)

The reason I am sure the problem is with my new Muse, is because my delta and theta have always been relatively balanced in my right and left hemispheres.....now bang on since using the new Muse - only the right side theta/delta has nosedived - but the left hasn't. You'll see it in the csv files I send you.

Excellent pick up with the Jan 20 typos - much appreciated.

And thanks for staying with me here - I'd love to get to the bottom of this.

[James]

After looking at the two sessions which you emailed, I think I was correct with my first guess; The old Muse is noisier than the new Muse. That's it

The difference is very slight, but it's there. The extra noise is just enough to bump the lower frequencies up exactly as seen in your graph.

If you look at the two compared side by side with the same fixed max/min, you can see that the old Muse RAW EEG is just a little bit fatter and that's what is making this difference.

As to why the new one is better, I'm not sure. It could be that Interaxon have made some slight improvements to the hardware, or given that your old one broke, it might be that the connections on the old one were not as good.

20v21.png (96.58 KiB) Viewed 2702 times

[lightinmyshadow]

Hi James,

Thanks. I see what you're saying with the extra 'noise' in TP9 – but take a look at my TP9 graph (above) - you can see that TP9 theta/delta readings haven't changed much from switching from the old muse to my new Muse.

It's the right side - (TP10 & AF8) with the reduced theta/delta issue.

Even if this new Muse does have less noise – it's not acceptable to me that it has less noise on the RIGHT side, but not the LEFT side sensors also.

This is giving me faulty readings.

I've also attached another TP9 image from the Old Muse below (dated 16.01.21) that's a bit neater - and less 'noisy' than the New Muse.

I'm going to have to buy a new muse 2, and compare them. I'll tell you what I find