ECG Signal Preprocessing Based on Change Step Iteration of the LMS Adaptive Filtering Algorithm

For there are power line interference and baseline drift to ECG signal, the signal to noise ratio of ECG is reduced enormously. Based on self-adaptive noise cancellation system, a step iteration changeable least mean square (LMS) algorithm is brought forward. The step-change factor is introduced in the process of the algorithm. The concrete changing process of the noise variance and the signal error are both considered, and the step is adjusted with the increase in the number of iterative to match with the convergence of adaptive filter. The effect of the algorithm in this paper is compared with that of the other LMS algorithm at the same time. The results show that the step iteration changeable algorithm can be implemented easily and its computational complexity is smaller. In addition, the error convergence rate of the algorithm is fast, and the filtering effect is good.