Simulation of Dynamic Systems with MATLAB® and Simulink®, 3rd Edition

4.12Case Study: Notch Filter for Electrocardiograph Waveform

An electrocardiograph (ECG) signal is corrupted with 60 Hz noise from an electrical power source. A portion of the noisy signal, sampled regularly at 0.004 s intervals, is shown in Figure 4.113.

Figure 4.113ECG signal corrupted with 60 Hz noise sampled at T = 0.004 s intervals.

A notch filter is needed to remove the noise. One realization of a second-order filter transfer function is given by (Orfanidis 1996)

H(z)=Y(z)U(z)=b[1−2(cosω0T)z−1+z−21−2b(cosω0T)+(2b−1)z−2]	(4.801)

where ω0 is the notch frequency (in rad/s). The filter parameter Q relates the notch frequency ω0 to ...