A noninvasive technique to monitor gastric electrical activity (GEA) and mechanical activity as an aid in assessing gastric motor function is presented. The GEA is measured with ordinary ECG electrodes located on the torso in the region above the stomach. The mechanical activity is recorded through an electrical impedance monitoring device. A study of a mathematical model of the electrically active antral part of the stomach in the body revealed that the waveform of the extracorporeally measured signals can be related to the direction of propagation of the GEA. This feature was confirmed experimentally.