Computer model of gastric electrical stimulation.

The aim of the study was to simulate gastric electrical stimulation using a computer model of gastric electrical activity and suggest a possible avenue toward reliable gastric pacing. Modeling was based on the conoidal dipole model of gastric electrical activity described earlier. It was assumed that local, nonpropagated contractions can be produced circumferentially using 4 rings of stimulating electrodes supplied with 2-sec phase-locked bipolar trains of 50 Hz, 15 V (peak to peak) rectangular voltage. Temporal and propagation organizations of gastric electrical activity described in the conoidal dipole model were used to derive the geometry of the stimulating electrodes and the time shifts for phase-locking of the electrical stimuli applied to the different circumferential electrode sets. The major assumptions and findings of the model were tested on two unconscious dogs. The model produced completely controllable simulated gastric contractions that could be propagated distally by phase-locking the stimulating voltage. The values of interelectrode distances in different rings, as well as the distances between the successive rings, were also derived. The concept of invoked circumferential contractions that are artificially propagated by phase-locking the stimulating voltage could be an avenue toward reliable gastric pacing of gastroparetic patients.