Correlation and comparison of magnetic and electric detection of
small intestinal electrical activity.
Bradshaw, L. Alan, Suhail H. Allos, John P. Wikswo, and William O.
Richards[acute]a.
Living State Physics Group, Department of Physics and Astronomy,
Vanderbilt University, Department of Surgery, Veterans Administration
Medical Center, Department of Surgery, Vanderbilt University School
of Medicine, Vanderbilt University, Nashville, TN 37232
APStracts 3:0257G, 1996.
The small intestinal basic electrical rhythm (BER) was detected
simultaneously with serosal electrodes and a transabdominal
Superconducting QUantum Interference Device (SQUID) magnetometer in
anesthetized rabbits. We induced mesenteric ischemia to correlate
serosal electrode recording of changes in the BER with the SQUID
magnetometer. The BER frequency was obtained by spectral analysis of
the data using Fourier and autoregressive techniques. There was a
high degree of correlation (R = 0.96) between the BER frequency
determined using the serosal electrodes and the frequency of the BER
ascertained from SQUID data. Additionally, the effects of an
electrical insulator on the external electric and magnetic fields
were studied in the rabbit model. The presence of an insulator
profoundly attenuates external electric potentials recorded by
cutaneous electrodes but does not significantly affect external
magnetic fields or serosal potentials. We conclude that SQUID
magnetometers could noninvasively record small intestinal BER that
was highly correlated with the activity recorded by invasive serosal
electrodes. The advantages of magnetic field measurements have
encouraged us to investigate clinical applications.
Received 6 May 1996; accepted in final form 13 November 1996.
APS Manuscript Number G177-6.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996