Dear James, I'm making progress with your software, thanks for it. Now, I have the same question than “jaycode” in the post “Understanding the unit of measurement used on the Chart“ that I think is not already answered. The question is:
“I need the power of all five wave types on μV^2 and you give it in dB. How could I convert dB to this unit?!
I’ve been reading the posts related to PSD an FFT etc.. and I understand the discrete frequency and spectrogram graphs in the app are done using a real time FFT from the RAW EEG data.
I need it the power data of every type of wave in this unit because it seems to be the standard unit with to compare the data.
Finally, I am using only the CSV file of Mind Monitor, I am not using your web or excel graphic.
Thanks a lot.
Oscar
Power Units : Belts or microvolts issue.
Re: Power Units : Belts or microvolts issue.
You can call the units whatever you like. PSD has no designated units. I was told by a staff member at Interaxon that they use Bels as the units because the calculation to get PSD is logarithmic.
Re: Power Units : Belts or microvolts issue.
Oscar, I was wondering about the same thing.
Technically, for PSD with input signals in μV, the unit is μV^2/Hz, and we typically convert that to dBμV/Hz by doing 10*log10(PSD). However Interaxon said it's Bel so I guess they only did log10(PSD), which is not quite common. If we multiply their value by 10 then I think we have dBμV/Hz, unless Interaxon did some additional scaling. To verify we may use raw the 256 Hz data to compute PSD and compare (I wanted to try that but did not get a chance to do it).
If the resistance is calibrated and used in the computation we might have dBm/Hz, based on which we can more easily figure out the power in mW.
Technically, for PSD with input signals in μV, the unit is μV^2/Hz, and we typically convert that to dBμV/Hz by doing 10*log10(PSD). However Interaxon said it's Bel so I guess they only did log10(PSD), which is not quite common. If we multiply their value by 10 then I think we have dBμV/Hz, unless Interaxon did some additional scaling. To verify we may use raw the 256 Hz data to compute PSD and compare (I wanted to try that but did not get a chance to do it).
If the resistance is calibrated and used in the computation we might have dBm/Hz, based on which we can more easily figure out the power in mW.