Barros A K, Yoshizawa M, Yasuda Y
Department of Knowledge-Based Information Engineering, Toyohashi University of Technology, Japan.
IEEE Trans Biomed Eng. 1995 Mar;42(3):324-7. doi: 10.1109/10.364522.
Impedance cardiography (ICG) may be altered by noises as respiration and movement artifacts, mainly during exercise. In this work, a scaled Fourier linear combiner (SFLC) event-related to the R-R interval of ECG is proposed. It estimates the deterministic component of the impedance cardiographic signal and removes the noises uncorrelated to this interval. The impedance cardiographic signal is modeled as Fourier series with the coefficients estimated by the least mean square (LMS) algorithm. Simulations have been carried out to evaluate the filter performance for different noise conditions. Moreover, the method capability to remove uncorrelated noises was also examined in physiological data obtained in rest and exercise, by synchronizing respiration and pedaling with a metronome. Analyzing the ICG power spectrum, it was concluded that the proposed filter could remove the noises that are not synchronized with heart rate.
阻抗心动图（ICG）可能会受到呼吸和运动伪影等噪声的影响，尤其是在运动期间。在这项工作中，提出了一种与心电图R-R间期相关的缩放傅里叶线性组合器（SFLC）。它估计阻抗心动图信号的确定性成分，并去除与该间期不相关的噪声。阻抗心动图信号被建模为傅里叶级数，其系数由最小均方（LMS）算法估计。已经进行了模拟以评估不同噪声条件下的滤波器性能。此外，还通过用节拍器同步呼吸和蹬踏，在静息和运动时获得的生理数据中检验了该方法去除不相关噪声的能力。通过分析ICG功率谱得出结论，所提出的滤波器可以去除与心率不同步的噪声。
