Detection of Small Bowel Slow-Wave Frequencies From Noninvasive Biomagnetic Measurements

• Published in: IEEE transactions on biomedical engineering Vol. 56; no. 9; pp. 2181 - 2189
• Main Authors: Erickson, Jonathan C., Obioha, Chibuike, Goodale, Adam, Bradshaw, L. Alan, Richards, William O.
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.09.2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Animals; Biomagnetics; Electric variables measurement; Electromagnetic Fields; Electrophysiological Phenomena; Frequency measurement; Gastrointestinal Motility - physiology; Interference; Intestine, Small - physiology; Intestines; Noise measurement; Signal processing; Signal Processing, Computer-Assisted; slow wave; SOBI; SQUID; SQUID magnetometers; Superconducting device noise; Superconducting devices; Swine; wavelet transforms
• ISSN: 0018-9294; 1558-2531; 1558-2531
• DOI: 10.1109/TBME.2009.2024087

We report a novel method for identifying the small intestine electrical activity slow-wave frequencies (SWFs) from noninvasive biomagnetic measurements. Superconducting quantum interference device magnetometer measurements are preprocessed to remove baseline drift and high-frequency noise. Subsequently, the underlying source signals are separated using the well-known second-order blind identification (SOBI) algorithm. A simple classification scheme identifies and assigns some of the SOBI components to a section of small bowel. SWFs were clearly identified in 10 out of 12 test subjects to within 0.09-0.25 cycles per minute. The method is sensitive at the 40.3 %-55.9% level, while false positive rates were 0%-8.6 %. This technique could potentially be used to help diagnose gastrointestinal ailments and obviate some exploratory surgeries.