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Exact(approximate) frequency of particular brainwave state
Posted: Fri Dec 09, 2022 3:56 am
by dusan
Hello,
Is there a way to know exact frequency of specific brainwave state ? Let's say I would like to know what exact frequency I've spent in Delta state or maybe most of time. Now I can distinguish only between 5 states, Delta, Theta, Alpha, Beta and Gamma. I am thinking to know more about my personal sleeping frequency to support it, not just Delta
From spec:
"FFT stands for Fast Fourier Transform. This computes the power spectral density of each frequency on each channel.
Absolute band powers are based on the logarithm of the Power Spectral Density of the EEG data for each channel."
Thank you.
Re: Exact(approximate) frequency of particular brainwave state
Posted: Fri Dec 09, 2022 8:52 am
by James
Yes and No.
You can see that in the discrete frequency graph and spectrogram, but obviously not when you are sleeping!
If you want to calculate that from recorded data, then you would have to do an FFT of the data in something like MATLAB.
Re: Exact(approximate) frequency of particular brainwave state
Posted: Fri Dec 09, 2022 10:19 am
by dusan
Re: Exact(approximate) frequency of particular brainwave state
Posted: Fri Dec 09, 2022 10:23 am
by James
I think it would be too much data for Excel to handle. To do FFT calculations you need to set the "Recording Interval" in settings to "Constant". This will give you 256Hz data (256 rows of data per second), which is requried for FFT. For 8 hours of sleep, thats 7,372,800 rows of data not including blink rows.
Re: Exact(approximate) frequency of particular brainwave state
Posted: Fri Dec 09, 2022 11:47 am
by dusan
Correct, Excel FFT is limited to 4096 samples
https://www.analog.com/en/design-notes/ ... excel.html
I may not need to analyze entire 8 hours, up to 1 hour long deep stage would be enough but 4096 is anyway too little.
Re: Exact(approximate) frequency of particular brainwave state
Posted: Sat Dec 10, 2022 8:25 am
by cricky
Hi i'm a Newbie, please answer my questions below..
1. What is the most DB Normal Range for users when using Absolute?
2. What is the physical dimension of Z Accelerometer?
3. What would be the highest DB of any State that you deem already crude effect as oppose to subtle effect?
4. What would be the equivalent DB state if a person is in a vegetative state?
5. My Alpha State went up to 180DB, so is that an accomplishment?
6. What does each graph do for you specifcally?
7. If I require my Pineal gland be always activated, what must be the DB range to accept that my pineal gland is pandiculating or actively pumping?
Re: Exact(approximate) frequency of particular brainwave state
Posted: Sat Dec 10, 2022 11:11 am
by dusan
There is a simple python script using FFT and generating graph even listening for Muse headband
https://github.com/vasilescur/FocusFriend
I could feed it with MindMonitor CSV data.