Performance Investigation of Marginalized Particle‑Extended Kalman Filter under Different Particle Weighting Strategies in the Field of Electrocardiogram Denoising

Background: Recently, a marginalized particle‑extended Kalman filter (MP‑EKF) has been proposed for electrocardiogram (ECG) signal denoising. Similar to particle filters, the performance of MP‑EKF relies heavily on the definition of proper particle weighting strategy. In this paper, we aim to investigate the performance of MP‑EKF under different particle weighting strategies in both stationary and nonstationary noises. Some of these particle weighting strategies are introduced for the first time for ECG denoising. Methods: In this paper, the proposed particle weighting strategies use different mathematical functions to regulate the behaviors of particles based on noisy measurements and a synthetic ECG signal built using feature parameters of ECG dynamic model. One of these strategies is a fuzzy‑based particle weighting method that is defined to adapt its function based on different input signal‑to‑noise ratios (SNRs). To evaluate the proposed particle weighting strategies, the denoising performance of MP‑EKF was evaluated on MIT‑BIH normal sinus rhythm database at 11 different input SNRs and in four different types of artificial and real noises. For quantitative comparison, the SNR improvement measure was used, and for qualitative comparison, the multi‑scale entropy‑based weighted distortion measure was used. Results: The experimental results revealed that the fuzzy‑based particle weighting strategy exhibited a very well and reliable performance in both stationary and nonstationary noisy environments. Conclusion: We concluded that the fuzzy‑based particle weighting strategy is the best‑suited strategy for MP‑EKF framework because it adaptively and automatically regulates the behaviors of particles in different noisy environments.