Adaptive cancellation of the pacing stimulus artifact in the gastric myoelectrical recordings

To evaluate the effects of gastric pacing, several electrodes are usually placed on the serosal surface of the stomach along the greater curvature so that one can be used for delivering electrical currents and others for recording gastric myoelectrical activity. One of problems with these recordings is the pacing stimulus artifact superimposed on the natural gastric myoelectrical signals which make it difficult to analyze accurately. This paper presents an effective transform-domain adaptive filtering method for the cancellation of the pacing stimulus artifact in the gastric myoelectrical signals obtained through serosal electrodes during gastric pacing. Results from both simulations and real signals demonstrated that the pacing stimulus artifact could be effectively canceled while the natural gastric myoelectrical signal was not affected by adaptive filtering.