I'm trying to filter out line noise(60Hz and 120Hz) from a EEG signals received over a bluetooth link. I'm proposing to use a IIR notch filter to filter out the line-noise which varies w.r.t to distance between the bluetooth transmitter and receiver. I'm not able to establish a clear relationship between the Notch filter parameters and the magnitude of line noise so as to avoid over-attenuation or under-attenuation to avoid dips and peaks at these frequencies in the spectrum. The problem is Q-factor and stop-band Bandwidth which define the notch filter don't directly relate to the stop band attenuation. If this is not possible is there any other equally efficient adaptive stop-band filtering method to achieve the same ? How can this be implemented w.r.t line noise measurement and corresponding filter parameter adjustments ?