Biomagnetic and bioelectric detection of gastric slow wave activity in normal human subjects-a correlation study

• Published in: Physiological measurement Vol. 33; no. 7; pp. 1171 - 1179
• Main Authors: Somarajan, S, Muszynski, N D, Obioha, C, Richards, W O, Bradshaw, L A
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 01.07.2012
• Subjects: Electrodes; electrogastrogram; Electromyography; Electrophysiological Phenomena; Female; Gastric Mucosa - physiology; Humans; Magnetics - methods; magnetogastrogram; Male; mucosal electrode; multichannel SQUID; Radiography; Signal Processing, Computer-Assisted; slow wave; Stomach - diagnostic imaging; Stomach - physiology; Wavelet Analysis
• ISSN: 0967-3334; 1361-6579; 1361-6579
• DOI: 10.1088/0967-3334/33/7/1171

We measured gastric slow wave activity simultaneously with a Superconducting Quantum Interference Device (SQUID) magnetometer, mucosal electrodes and cutaneous electrodes in 18 normal human subjects (11 women and 7 men). We processed signals with Fourier spectral analysis and SOBI blind-source separation techniques. We observed a high waveform correlation between the mucosal electromyogram (EMG) and multichannel SQUID magnetogastrogram (MGG). There was a lower waveform correlation between the mucosal EMG and cutaneous electrogastrogram (EGG), but the correlation improved with the application of SOBI. There was also a high correlation between the frequency of the electrical activity recorded in the MGG and in mucosal electrodes (r = 0.97). We concluded that SQUID magnetometers noninvasively record gastric slow wave activity that is highly correlated with the activity recorded by invasive mucosal electrodes.