Biomagnetic and bioelectric detection of gastric slow wave activity in normal human subjects--a correlation study.
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.
Department of Surgery, Vanderbilt University, Nashville, TN, USA. suseela.somarajan@vanderbilt.edu
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S
Somarajan
N D
ND
Muszynski
C
C
Obioha
W O
WO
Richards
L A
LA
Bradshaw
D004566:Electrodes; D004576:Electromyography; D055724:Electrophysiological Phenomena; D005260:Female; D005753:Gastric Mucosa / Q000502:physiology; D006801:Humans; D008280:Magnetics / Q000379:methods*; D008297:Male; D011859:Radiography; D012815:Signal Processing, Computer-Assisted; D013270:Stomach / Q000000981:diagnostic imaging / Q000502:physiology*; D058067:Wavelet Analysis