EEG - frequency processing question
Posted: Tue Mar 20, 2012 5:15 am
Hello,
I am trying to take the 2D array of samples from 64 EEG channels in the ring buffer, and process these to determine in real-time the respective power of delta, theta, alpha, beta, and gamma brain wave activity.
I am attempting to do this using bandpass filters within an auto-indexing for-loop, however the output graph is not displaying any power in these frequency bands. The only error I can see is a message in the filter control suggesting that the Nyquist stability criterion is not being met. According to our calculations, the sampling rate (2048 Hz) should be more than enough to accommodate the filter settings.
Is there a better way to go about this? Might I be missing something? Any assistance would be very much appreciated.
Best,
Matthew
I am trying to take the 2D array of samples from 64 EEG channels in the ring buffer, and process these to determine in real-time the respective power of delta, theta, alpha, beta, and gamma brain wave activity.
I am attempting to do this using bandpass filters within an auto-indexing for-loop, however the output graph is not displaying any power in these frequency bands. The only error I can see is a message in the filter control suggesting that the Nyquist stability criterion is not being met. According to our calculations, the sampling rate (2048 Hz) should be more than enough to accommodate the filter settings.
Is there a better way to go about this? Might I be missing something? Any assistance would be very much appreciated.
Best,
Matthew