Mohebbi Maryam, Hesar Hamed Danandeh
Department of Biomedical Engineering, K. N. Toosi University of Technology, Tehran, Iran.
J Med Signals Sens. 2018 Jul-Sep;8(3):147-160. doi: 10.4103/jmss.JMSS_14_18.
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.
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.
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.
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.
最近,一种边缘化粒子扩展卡尔曼滤波器(MP-EKF)已被提出用于心电图(ECG)信号去噪。与粒子滤波器类似,MP-EKF的性能在很大程度上依赖于合适的粒子加权策略的定义。在本文中,我们旨在研究MP-EKF在不同粒子加权策略下在平稳和非平稳噪声中的性能。其中一些粒子加权策略是首次引入用于ECG去噪。
在本文中,所提出的粒子加权策略使用不同的数学函数,基于噪声测量和利用ECG动态模型的特征参数构建的合成ECG信号来调节粒子的行为。其中一种策略是基于模糊的粒子加权方法,其被定义为根据不同的输入信噪比(SNR)来调整其函数。为了评估所提出的粒子加权策略,在MIT-BIH正常窦性心律数据库上,在11种不同的输入SNR以及四种不同类型的人工和真实噪声下评估了MP-EKF的去噪性能。为了进行定量比较,使用了SNR改善度量,为了进行定性比较,使用了基于多尺度熵的加权失真度量。
实验结果表明,基于模糊的粒子加权策略在平稳和非平稳噪声环境中均表现出非常良好且可靠的性能。
我们得出结论,基于模糊的粒子加权策略是最适合MP-EKF框架的策略,因为它能在不同噪声环境中自适应且自动地调节粒子的行为。