0
$\begingroup$

I'm trying to do Analysis of EEG Signal for the Detection of epileptic seizure so in the pre-processing of the EEG signal I use a low pass FIR filter

d1=designfilt('lowpassfir','PassbandFrequency',0.15,'StopbandFrequency',0.2,'PassbandRipple',3,'StopbandAttenuation',60,'DesignMethod','equiripple');
a = filtfilt(d1,deriv1);

I want to know if the values above for PassbandFrequency and StopbandFrequency are right.

$\endgroup$
  • $\begingroup$ Hi! These are MATLAB functions right? It's better if you clarify. $\endgroup$ – Fat32 Mar 16 '17 at 11:08
0
$\begingroup$

Assuming MATLAB functions to be used, passband frequency 0.15 means $\omega_p = 0.15 \pi$ whereas stopband frequency 0.2 means $\omega_s = 0.2 \pi$ and since $\omega_s > \omega_p$ these settings qualify for a proper lowpass filter.

Also passband ripple being $3dB$ and stopband attenuation being $60 dB$ are valid choices (although more exact specifications requires the knowledge application requirements)

The equiripple option designs a filter in which the designed filter magnitude error is distributed accross the pass and/or stop bands in equal amounts so as to reduce the filter length to a minimum while still meeting the maximum of the allowed peak error criteria.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.