In vivo detection of normal and pathologic bowel electricalactivity using a SQUID magnetometer

摘要

The Superconducting QUantum Interference Device (SQUID)magnetometer can non-invasively detect the magnetic fields created bythe Basic Electrical Rhythm (BER) of the Gastrointestinal Tract (GIT).Using anesthetized adult male New Zealand rabbits the authors recordedsignals from two isolated bowel segments at the same time, before andafter ischemia was induced in either one or both bowel segments. Thedominant frequency peaks for each period of recording were determinedusing autoregressive (AR) spectral analysis. There was a significantfall in the BER frequency in the ischemic segment from 11.8±0.9to 7.8±0.6 cycles per minute (cpm), while there was no change inthe normal bowel. It was possible for two observers (LAB, WOR) who wereblinded to the preparation, to identify which bowel segment wasischemic. The results of this experiment demonstrate the ability of theSQUID magnetometer to noninvasively detect and differentiate signalsfrom normal and ischemic bowel sources