Notch filtering minimizing artifacts in signal

1. What is the purpose of notch filter?
2. What does notch filter do on EEG?
3. Why is notch filter used in ECG?
4. Can filters improve signal quality?

What is the purpose of notch filter?

Notch filters are used to remove a single frequency or a narrow band of frequencies. In audio systems, a notch filter can be used to remove interfering frequencies such as powerline hum. Notch filters can also be used to remove a specific interfering frequency in radio receivers and software-defined radio.

What does notch filter do on EEG?

A notch filter is typically an aggressive filter that strongly attenuates the power over a narrow region of the spectrum. For example, a notch filter at 60 Hz / 50 Hz is used to filter out power line noise with minimal disruption to the rest of the signal.

Why is notch filter used in ECG?

Several kinds of notch filters (analog and digital) were implemented for evaluation of the distortion caused on ECG signals. These filters were applied to ECGs of humans and rats and then distortion estimates were computed from their resulting signals.

Can filters improve signal quality?

More than half of the filters were found to improve the signal quality. Figure 2 displays a stacked histogram of the SQI for G1, G2, and G3, which details the different filters and orders.