A planar array of electrodes has been used to provide a longitudinal s
ection of the stomach. Impedance changes at the gastric frequency of 0
.05 Hz can be detected. The changes are mainly located around the peri
phery of the stomach image, suggesting that they are the result of mov
ement of the stomach wall. The generation of a vector histogram of wal
l movement gives a non-invasive method which appears to quantify the p
eristaltic waves which produce transport in the stomach.