H2(z) and H3(z) was 128 and the coefficient convergence rates μ1, μ2 and μ3 were 0.001. The output of H1(z) is y1(n), which is an estimation of the line artifact present in the EEG. This signal y1(n) is subtracted from the corrupted d1(n) to produce the error e1(n), which is the EEG without lineinterference. The e1(n) error is forwarded as the corrupted input signal d2(n) to the second stage. The reference input x2(n) of the second stage can be either a real or artificial ECG. The output of H2(z) is y2(n), representing a good estimate of the ECG artifact present in the EEG record. Signal y2(n) is subtracted from d2(n); its result produces error e2(n). Thus, we have obtained the EEG without line and ECG interference. Then, e2(n) enters into the third stage as the signal d3(n). The reference input x3(n) of filter H3(z) is also a real or artificial EOG and its output is y3(n), which is a replica of the EOG artifact present in the EEG record. Such y3(n), subtracted from d3(n), gives error e3(n). It is the final output of the cascade filter, that is, the EEG without artifacts.