Volume conductor effects on simulated magnetogastrograms.

We simulated the magnetic field due to gastric electrical activity (GEA) using a temporally and spatially moving dipole source. The contributions of the volume conductor to the total magnetic field were examined. The volume conductor was represented using three simplified models (free-space, spherical and half-space) and an anatomically realistic torso model. We compared the patterns and the directions of the resultant magnetic fields generated using these volume conductor models. We concluded that all the simplified models produced significantly different magnetic fields when compared to the anatomically realistic model. Therefore, an anatomically realistic model is necessary for any modeling studies to accurately calculate the magnetic fields from GEA.