Estimation of instantaneous bandwidth and reconstruction of noisy ECG signal measured by a 24-hour continuous healthcare system for the elderly and people with disabilities

In this manuscript, a case study is conducted on bio-signals of timevarying spectral content with the purpose of developing a quality of life engineering product. The study deals with noise reduction of electrocardiogram (ECG) for detecting abnormality of the heart system during daily life. Instantaneous bandwidth (IB) of ECG is estimated and is used adaptively as IB of variable bandwidth filter (VBF) for suppressing noise whose Fourier spectrum overlaps with that of ECG and estimating more accurately parameters such as onsets, ends, rates, intervals and durations on the six principal waves of ECG measured during daily life. The proposed method based on the VBF improves the SNR on the P, Q and T waves without damaging the QRS complex, different from, the methods based on the Fourier spectral analysis