Spatial and temporal variations in the magnetic fields produced by human gastrointestinal activity

Magnetoenterography (MENG) is a new, non-invasive technique that measures g astrointestinal magnetic signals near the body surface. This study was unde rtaken to evaluate the temporal and spatial characteristics of the magnetic signals generated by gastric and duodenal slow wave activity. The gastroin testinal magnetic fields of eight normal subjects were measured for 60 minu tes in both the fasting and fed state using 36 magnetic sensors simultaneou sly. The results were displayed as a succession of maps over time showing t he temporal evolution of the spatial distribution of the signal over the up per abdomen. In all subjects, slow wave activity of the stomach centred at 3.0 +/- 0.5 cycles min(-1) in both the fasting and fed state was observed. The duodenal signal at 11.0 +/- 1.0 cycles min(-1) was observed in four sub jects. The spatial distribution of these two signals is distinctly differen t The observed spatial and temporal variations are described in terms of a model used previously to explain the potentials observed in electrogastrogr aphy (EGG).