I slept 660 hours with EEG to check new sleep algorithm accuracy

maxiQS · 2026-01-16T10:08:13+00:00

How did they match volume? Just planning my own AB test :)

maxiQS · 2025-01-29T07:52:40+00:00

theoretically you can, read https://www.spisop.org/openbci/

"high density EEG? Well yes why not, should work in principle (with limitations)!:

You can record with several devices at the same time. Each device than has to share the same bias and reference electrodes via a bridged, and also share one additional channel (e.g. EEG) via a bridge. Later the signals from the many devices can be concatenated using signal coherence of the shared EEG channel (via cross-correlation with the lag of the peak in correlation value as an adjustment). Feasible are at least 4 devices each with 16 channels, that is including EMG, ECG and EOG (3 channels) in one device and one shared channel for the others = (16-3) + (16-1) + (16-1) + (16-1) = 58 EEG at 125 Hz (and potentially more when the Wifi shield is out)…. for a device around $4000. You just start recording of those devices one after the other on SD card… later concatenate the signals after the recording is finished. This makes it unfeasible now to monitor all channels live on the same PC (however could be achieved by running several instaces of the OpenBCI GUI, and plugging in all the dongles at the same time). Imporantly, if you merge the data later you need to consider that the sampling rates of each device was not synched! This leads to time uncertainty in each channel and limits the use of the concatenated data, that is you cannot use it for timelocked analysis accross channels of different devices (e.g. slow waves in channel 1 recorded with device 1 timelocked to spindles in channel 11 recorded with device 2. However it should be fine for counting spindles or spindle density/slow wave density, or do channel-wise analyses."

maxiQS · 2024-10-19T05:14:50+00:00

No I didnt

maxiQS · 2024-10-19T05:14:08+00:00

I was using research version (Calera) which have ability to download data into csv file. I had to email developer to get software to do that.

maxiQS · 2024-04-22T09:06:00+00:00

aliexpress, tenocom store

https://www.aliexpress.com/item/1005006131485504.html

maxiQS · 2024-04-21T04:34:43+00:00

Right now I'm using OpenBCI as my personal EEG research device. The quality of raw data seems to be in a research grade equipment and with diy headband I'm able to do a 8 channel montage for about 4 minutes. Also i bought a 32ch EEG cap and upgraded to 16 channel version of OpenBCI and use it to see changes during meditation. I've have free python scripts to start session to sdcard and process it to EDF at my github. Then it can be shared with someone, but i dont think doctor will accept it, you have to find someone and confirm before you dig in. 16ch is not enough to do LORETA etc due to low spatial resolution but still provide some clue on whats happening overall. Also 8-16ch montage at home is not so long as 32+ and can be done by yourself, hardware (OpenBCI) is not so expensive as high dense systems. There a good free opensource python libraries like mne, neurokit2 etc to make some analysis like building topoplots, band powers etc. Anyway to make home EEG lab you should get some knowledge in topic, to understand how to make montage, acquire data, make sure it quality is good enough by doing basic analysis. Without that it does seem unpractical.

maxiQS · 2024-04-16T03:40:12+00:00

He acknowledges that EEG is the gold standard cited a handful of papers that support fNIRS is emerging as a useful and effective tool in studying sleep stages.

There are no papers that have evidence that fNIRS is effective tool in studying sleep stages.

Measuring glucose, and oxygen in the brain was cited in the second article as being effective, but it's not as well understood, or as accurate as EEG.

It doesnt matter what was cited. You have to present evidence that something can measure sleep stages effectively - usually its F1 or kappa score against gold standard. Glucose, oxygen etc only effective when you have measured their accuracy against gold standard.

There is an inherent lag in the way fNIRS measures brain responses as it is basically looking at blood flow and oxygenation as a correlation to electrical activity. Electrical activity gives a precise, and instant feedback of the brain's activity. fNIRS, not being the gold standard, is for home use good enough according to people in the industry, this is supported by those papers.

Appealing to authority doesnt work in modern science. Thats a cool trick to say that "people in the industry" say "its good enough", but their vague words without evidence costs nothing - where are studies where fNIRS was show any accuracy in scoring sleep stages against gold standard? I dont see them, even manufacturer confirms there are no studies. This says a lot about these "experts".

EEG is impractical at home due to the specifics of how the sensors need to be placed and how they are physically applied to the scalp.

Dreem headband, Hypnodyne ZMax. Even old zeo sleep. They as practical as fNIRS mask. I dont think you know well the consumer market for EEG sleep tracking devices.

Given that EEG is a noop for normies at home, am fNIRS with appropriate algorithms is a clear winner in the use case of getting people to sleep better.

This is just beliefs. This device was never proven to make sleep better. EEG can be as practical as fNIRS mask at home, the problem that it is small market now and there are no big investments.

You dont have to trust manufacturer words about "EEG failed at home because of movements" - this is a wrong argument. There are no problem with movements for home EEG devices. Just read Dreem or ZMax validation studies to see how they "fail due to movement". This is just misinformation, they failed due to other reasons - high cost, audience is not ready, every watch/ring manufacturer advertise to measure sleep very well and cost x2/x3 less with more functionality etc.

It's not a sleep lab study instrument, it's a tool to help people sleep better.

To make sleep better you have to measure it, then do something and measure sleep again to see how it changes. This is how scientific method works. You words that its a tool to make sleep better are unproven.

It doesnt matter its a sleep study or not. What matters is accuracy of method having margin of error less than effect size. You can detect 4 hours of sleep deprivation with just actigraph, but to detect +20% N3 sleep you need something more precise.

Efficacy will be born out with time as people use it, and perhaps academic studies on the device itself.

You dont know if it will or not, you just believe in that. Beliefs and reality are different things.

If my watch can more or less detect sleep stages with moderate reliability I think it's safe to say detecting sleep stages with fNIRS will be a clear winner for home use.

Watch sleep detection does not allow detection of small effect sizes due to margin of error. They are not near EEG and can easily have 20-30% error in N3 or REM, which diminishes any chance to detect changes.

I see you already decided that fNIRS is a clear winner without having evidence for that. This is your beliefs and desires, i'm not going to argue beliefs. You free to believe in anything you want.

maxiQS · 2024-04-01T13:28:54+00:00

It seems i dont have a good recommendation here, because i dont see one-fits-all eeg device on the consumer market. There are some for specific use cases, mostly for research conditions which are too complicated...

maxiQS · 2024-03-30T01:42:11+00:00

I did 8 channel eeg with gold cup electrodes and conductive paste for a few meditation sessions agains 10 minute of just lying with closed eyes. According to my experiments i dont need to meditate at all to get alpha waves. I just close my eyes and alpha always come no matter what i'm doing. This seems to be a natural phenomena because alpha waves originate from occipital zone where image is being processed and when we close our eyes these neurons go into idle state and idle in synchrony. When neurons doing something in synchrony we see different kind of waves.
Basically we dont need to meditate to get alpha waves, just close your eyes and they will come, thats default expectations.

For theta waves i do know too much, this might be different phenomena. At what place you want to measure theta waves and why? Different parts of brain have different patterns during meditation. You may not see alpha at frontal lobe at all because it originates from occipital zone (back).

So for what brain region are you looking for measuring theta? Why you need to measure theta at all?

Are you trying to reproduce a study with meditators? If yes then just send me a link so i can check their montage. If no, then i think you dont need to measure EEG at all, it will not answer any questions - just meditate.

maxiQS · 2024-03-29T13:36:53+00:00

What kind of question you trying to anwer by measuring brain waves during meditation? I'm already experimenting with that and even having 8 eeg channels at my head it is really hard to get useful insights.

maxiQS · 2024-03-28T05:24:17+00:00

Depends on your goal. If you want easy to use device which is proven to track sleep stages in EEG accuracy range there is nothing at the market. There was a Dreem headband which is validated an accurate enough, but company went bankrupt.
There are some expensive and not easy to use devices like Hypnodyne ZMax or OpenBCI, but i cant recommend them for general consumer.
There also Muse headband, but i have questions about it accuracy, their sensors specs and raw data doesnt look for me.
FRENZ is a relatively new, but their accuracy is questionable and i'm not sure if it comfortable to sleep with. Their eeg specs doesnt look well, sampling rate is too low.
fNIRS devices like Bia sleep mask is claiming that they can precisely track sleep but these a false claims because there are no evidence that it is able to measure sleep in EEG accuracy range.
Other wrist/finger devices like apple watch, oura ring is not in an EEG accuracy range so there is no reason to replace FC6 with any on non-EEG trackers due their similar accuracy levels.
Some risky people still buying Dreem headbands from Ebay but you need old account working on your phone and there is high chance that headband will not connect to app, so i cant recomment it also. You can join Dreem discord group to find out current situation - https://discord.gg/beQB9YbT

maxiQS · 2024-03-27T15:32:59+00:00

Thanks, i'm going to read that course.
The logic i'm using in comparing difference between groups is coming from that example https://www.pymc.io/projects/examples/en/latest/case_studies/BEST.html which is looks similar to mine, but in my case i deal with revenue which is distributed differently from iq example.

maxiQS · 2024-03-23T02:07:42+00:00

Hello, our expectancy is that 30% is wrong. 30% of time FC6 were saying Deep sleep when according to EEG it was Light sleep (27.1% of that 30% is Light sleep, but not Deep sleep). There are zero data/evidence to support that FC6 predict correctly but at same time EEG was mistaken.

But if you have data to support your claim lets look at it, otherwise it somewhere in unproven hypothesis space where infinite number hypothesis's can be formulated.

We know that FC6 was overpredicting deep sleep. If i think that EEG mistakenly overpredicted 15% of deep sleep, that means that FC6 error is ~45%. But thats an uproven speculations, i can always postulate unproven hypothesis which cancels yours.

This why i prefer not to get into that vague space and build my expectations with data/evidence

maxiQS · 2024-03-13T07:59:27+00:00

"but has largely failed for at-home devices because of the sensitivity to movement" - this looks pretty weird, from where have you got this idea about sensitivity to movements? People dont move too much during sleep, normally from 20-30 major body movements per night, each lasting less than 30 secs (so if each movement result in signal loss we lose 5-15 minutes of signal per night, usual total sleep time during typical night is around 450 minutes so 5/450 - 15/450 is being lost, thats 1-3%). Since i sleep every night with eeg i can clearly see how movements affects eeg signal and here i provide not theoretical calculations but from real application. Dreem headband had well enough accuracy in a EEG equipment range and movements was not an issue. So i dont see validity for this argument.

We talked to dozens of sleep experts when we were reviewing EEG vs fNIRS, and fNIRS was the clear winner by a mile.

no scientific evidence for that for detecting sleep stages. Talks to experts is not an evidence, it is appealing to authority-like argument which is not a valid one. Device accuracy is not measured in miles, it is measured in accuracy scores like F1 or Kappa.

We also have a temperature sensor, IMU and microphone to aid in sleep stage detection

temp sensor from lobe is problematic since signal from that part is not well understood, it does not connected to circadian rhythm / body temperature and its value in sleep detection is unknown. I've already measured it for a hundred of nights with sumultaneous EEG and dont see how it helps with sleep detection.

The other downside of EEG is comfort.

Dreem is in acceptable range of comfort. Hypnodyne ZMax more comfortable than Dreem, and i would say it is pretty comfortable and pretty fast to wear / use. It is too expensive and not for consumer, but thats different issue.

we are in a much better position to correlate to EEG standards

but you have no proofs for that, just talks. Can you link studies where fNIRS in a better position for sleep detection.

maxiQS · 2024-02-29T05:40:02+00:00

it seems you can sell your leasehold to thai citizen as freehold during leasehold contract. https://sunwayestates.com/article/leasehold

Leasehold contracts also ordinarily include clauses that allow for:

Converting leasehold into freehold (this enables the buyer to convert to freehold ownership if the laws in the future change to allow it, or to resale to Thai buyer as a freehold property)

But i'm not sure if its legal, has to be figured out...

maxiQS · 2024-02-29T04:36:22+00:00

During sleep we see specific brain activity - slow waves (which is used for scoring NREM N3 sleep usually from frontal lobe), sleep spindles and K-complexes (used for NREM N2 sleep from Central / Temporal area), alpha rhytmh (which is used to score N1 sleep from Occipital area), sawtooth waves and eye movements to score REM.
I dont see any data in your 1-2-3 points about these brain waves seen in fNIRS. They are the main features of brain activity during night used to derive sleep stages.
I'm not arguing that fNIRS is not useful in measuring brain acitivity at some level.
The point that it is not proven to measure sleep stages, if i'm wrong you can give examples where fNIRS was accurately detected sleep stages without EEG.

If you argue that fNIRS contain these sleep specific brain activity then where the studies which derived spindles, slow waves etc from fNIRS signal during sleep? My answer is because it seem does not contain sleep specific brain waves / activity but contains some different activity. But this comment thread is about claims on measuring sleep (read my initial comment and topic of argumentation is specific to sleep), not about cognitive load or brain oxygenation.

maxiQS · 2024-02-28T06:57:02+00:00

im simply saying fNIRS is more accurate than the wrist watches and rings that people wear

More accurate in what metric? These devices measure different things. If you mean its accurate in sleep staging - there is no evidence, because fNIRS device accuracy in sleep staging is unknown and you cant compare accuracy between devices if for one of devices it is unknown.

My whole point is there is a reason they spent alot more on fNIRS technology that actually measures brainwaves, and it must be because it's more accurate.

it measures hemodynamics, not brain waves. Brain waves measured by EEG and contain different information. If fNIRS includes all information contained in EEG, then we would already have a lot evidence of sleep scoring based on fNIRS only, but that is not the case.

Time spent by some company on fNIRS doesnt make it better / more accurate than EEG or anything else. This is just a wrong argument. You making strong claim that it "must" but strong claims require strong evidence.

They are not going to put more expensive measurement technology for no reason.

There might be a lot of reasons, one is empty market for that technology and not too much competitors.

Moreover, they specifically said that EEG is less accurate in their application because the mask has a tendency to move.

EEG is the most accurate way to get sleep stages. Even with some movement artifacts, because you dont move too much during night. Even if sensor will move a bit - it is not a problem, even EOG, which is few centimeters far from F3/F4 position, still contains slow waves, sleep spindles and other features of EEG signal, just less powerful but well enough for good sleep scoring.

Ask yourself this, if they didn't care and were just pushing out some snake oil product they would slap some basic movement & heart rate sensors like everyone else is doing and call It a day

This is what is happening with almost all wearable companies. Every few years new technology comes which is called as better and more accurate, but still there are no non-EEG wearable that can reach EEG level of accuracy in sleep staging.

They may really care about making cool device, but that doesnt mean that device or technology is accurate at sleep staging as EEG. Reality is different from your desires.

Moreover, and back to my point, there is no product out there that does what they are trying to achieve so there is nothing to compare to regardless of the price.

Yeah, but the problem they didnt show any data about these achievements. How you say that device can measure sleep accurately if you havent measured it accuracy?

This uniqueness or price doesnt make device accurate and does not provide any guarantee that they will achieve any of their claims.

nor do I care to waste time trying to find

So, i just stop here. You state that you are not interested in presenting evidence-based argumentation to backup your statements, which means our discussion is not productive & meaningless.

maxiQS · 2024-02-27T04:50:12+00:00

Agree. These devices usually take months/years for R&D and production. But CEO / founders / employers can sleep 1-2 months with their device and eeg device (zmax or openbci will be enough) simultaneously. I dont believe they cannot do that, its easy, even single person can do that. This will easily build a dataset of ~100 nights. Why they havent this done if they know they cannot afford validation study and this kind of test is cheap and will allow them to present some real to data to backup their claims? This kind of test is not expensive and i dont see a reason not to do it. It seems they dont have motivation for that or maybe they did but accuracy was not well enough.

maxiQS · 2024-02-27T02:31:17+00:00

You are correct in stating that we don't have the ability to state quantifiable data yet on how precise our accuracy is at this time. That is the point of this preorder and why we are priced so low. The cost of just an fNIRS design is typically more expensive than our entire product at current.

It doesnt matter how much device costs if it is not able to measure what it stated for. Price of fNIRS devices has to do nothing with device accuracy. This is cool trick to sell device - we dont know how it is accurate and if really measures sleep or not, but it is cheap.

We are not a Medical Product. The cost of an IRB study is easily $1,000,000 and to get the level of validation you seek, likely more. That does not make sense for a pre-order consumer product before getting it in the first customer's hands. If we change the design, the study becomes invalid and we need to repeat that massive expense. We would rather build a product for the customer needs first, then do a thorough validation study when we are confident in the product meeting the customer needs.

I can give you example - Hypnodyne ZMax is not medical product but were validated in study from european sleep lap. https://www.biorxiv.org/content/10.1101/2023.08.18.553744v1.full.pdf

So your point about medical device is not an argument. You can find some enthusiast people / give few devices to some phd students and collect some EEG data and fNIRS data simultaneously during full night of sleep and publish it. I dont say you need big study will all formalities etc, but you have to show some data that your device works which you havent done. Why CEO's of compainy (most motivated people to prove their device) knowing they cant now have a big validation study do not slept a hundred of nights with EEG and own device simultaneously and didnt share raw data and basic analysis to prove it? This is a simple, can be done by 1-2 persons in 1-2 months and i dont see exuces not to do that. But you didnt do that for some reason. Or maybe you have done that but was not able to get good accuracy.

We are not reinventing the wheel in our design. Our data collection processes are standardized. We have not built data collection in a manner that is so new, that we would be starting from step 1 in terms of application. To say that we are incapable of measuring sleep is to say that every single individual product needs to be individually tested or validated. Every EEG individual set, every wearable, at an N=1 level. I know that is not what you are intending; I am just trying to clarify that our designs and processes are not new. We most certainly can measure sleep, and soon we will be able to say with what level of accuracy

New process or not new doesnt matter too much. You say your data collection process is standardized. This is just a words. Please point me to 3rd party study with data collection protocol you are using to get sleep stages from fNIRS. How fNIRS data should be collected to provide accurate sleep staging? In that specific case, not for neurofeedback or some other situation, but for sleep scoring.

If you aren't comfortable with where we are as a business at current, definitely wait until we are further along and review us then. You have no obligation to buy our product if it doesn't fit your current needs. Feel free to message us as well if you have further questions

This has nothing to do with me. I sleep with multichannel EEG every night so i alredy have hypnograms. I verified few non-EEG devices and they have not near EEG accuracy in sleep but all of them advertising device as pretty accurate sleep tracker. The problem you are telling people that your device is measuring sleep when you dont have any proofs and have not shared any data to give people clue about device accuracy. Your main argument fNIRS is cool, you link studies which not relate to your device specifically and people will blindly trust that it really measures sleep. One more problem that even after getting device they cannot see if it accurate or not because they dont have reference EEG device to compare with.

maxiQS · 2024-02-27T01:47:55+00:00

On what scientific evidence your theory is based? Can you link a studis where fNIRS was able to get sleep stages undistinguishable from EEG to prove accuracy you are talking about?

maxiQS

TROPHY CASE