Portable Electrocardiogram System Based on iDR-RLS Filtering
摘要
The adaptive filtering algorithm recursive least squares (RLS) is widely used for the elimination of motion artifacts in electrocardiogram (ECG) signals. However, RLS suffers from the overshoot phenomenon, which affects its filtering performance. In this work, we proposed a data reuse method for ECG signal processing to achieve the suppression of the overshoot phenomenon while filtering the ECG. We investigated the ECG filtering performance of data reuse RLS (DR-RLS) and proposed an improved DR-RLS (iDR-RLS) for ECG filtering by incorporating the morphological features of ECG to interval for data reuse. Compared with the conventional DR-RLS,RLS, VMD, and FIR algorithms, iDR-RLS increased the signal-to-noise ratio of the filtered signals by 4.3221, 1.3132, 6.3114, and 3.2446 dB, respectively. The additional computational cost of the proposed method is only 0.08% of the computational cost of the RLS algorithm itself when the data reuse number is 4. In addition, we implemented the proposed algorithm in hardware based on STM32F407 and developed an ECG portable processing system to verify the efficacy of the algorithm. For ECGs with a sample capacity of 5000, the iDR-RLS algorithm exhibits a slightly longer operational duration (0.09 s) than the RLS algorithm. In addition, for 36 sample sets from the database, the filtered signal produced by the proposed algorithm demonstrates an error of −0.001060 ± 0.074392 mv compared to the original signal. This study illustrates the efficacy of data reuse in mitigating motion artifact noise in ECG.