Adaptive cancellation technique in processing myoelectric activity of respiratory muscles

Abstract

Spectral analysis of myoelectric activity of the chest muscles is a promising diagnostic tool for respiratory diseases. Reduction of the corrupting cardiac activity from the recorded myoelectric activity of the chest muscles is essential because of the spectral overlap of both the signals. The adaptive noise cancellation technique was used to reduce the interfering cardiac activity from the recorded myoelectric activity. The adaptive noise canceller implemented in a transversal structure was found to successfully reduce the corrupting cardiac activity. This paper describes the cancellation of the corrupting cardiac activity from the recorded myoelectric activity using adaptive noise cancellation technique and the characteristic features of spectra of EMG signals.

Elimination of electrocardiogram contamination from electromyogram signals: An evaluation of currently used removal techniques

“…Other types of ECG removal techniques reported in the literature are the combination methods of adaptive noise cancellation (ANC) and event synchronous cancellation (ESC) [1,2,14,18,32], and clipping [7]. The ANC and ESC methods use the collection of a pure ECG signal in time Fig.…”

“…The ECG signal is then subtracted from the collected contaminated EMG signals followed by an automatic adaptive filtering method [1,2,14,18,32]. Since the test signals were created by superimposing the pure ECG and EMG signals, subtraction of the ECG signal would result in 100% efficacy of this method, which could be misleading.…”

“…Unsurprisingly, controversy over the best method to remove ECG contamination from EMG signals persists. Difficulties in comparing between studies arise due to the different signals used (diaphragmatic or skeletal muscle), electrodes, collection systems, and methods (esophageal or surface EMG) [1,6]. Moreover, the technique efficacy is usually evaluated by visual inspection without additional quantification, as the investigations are usually performed on contaminated EMG, leaving the effect of the removal technique on the EMG signal largely unknown.…”

Adaptive filtering for ECG rejection from surface EMG recordings

“…Six different recursive algorithms were tested using two different principles: four of the gradient (least mean square, LMS) family and the other two of the fast recursive least square (FRLS) family [1,3,4].…”

Removal of ECG interference from surface respiratory electromyography

“…However, this method results in signal information loss, which will affect the original signal. Marque and Akkiraju [3,9] proposed an adaptive noise canceller using the Widrow adaptive filter. This method requires an additional channel to record the ECG signal for use as a reference input for the noise canceller.…”