COMPUTER-MODEL OF GASTRIC ELECTRICAL-STIMULATION

The aim of the study was to simulate gastric electrical stimulation us ing a computer model of gastric electrical activity and suggest a poss ible 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 produce d circumferentially using 4 rings of stimulating electrodes supplied w ith 2-sec phase-locked bipolar trains of 50 Hz, 15 V (peak to peak) re ctangular voltage. Temporal and propagation organizations of gastric-e lectrical 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 comp letely controllable simulated gastric contractions that could be propa gated 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 invok ed circumferential contractions that are artificially propagated by ph ase-locking the stimulating voltage could be an avenue toward reliable gastric pacing of gastroparetic patients.