BACKGROUND: Development of electrogastrography, the recording of gastric electric rhythm from cutaneous electrodes, for clinical purposes has been hampered by methodologic problems and the lack of an ambulatory technique. We have evaluated a newly developed system for ambulatory electrogastrography. METHODS: 24-Hour recordings were obtained from 30 healthy volunteers. We used digital filtering, a Hamming window, and spectral analysis to determine the dominant frequency of successive 256-sec segments of data. RESULTS: Low-frequency noise disturbed the primary signal. After secondary filtering a stable normogastric (2-4 cpm) rhythm was present during a median of 49% (range, 34-79%) of the recording time. The mean frequency of gastric electric activity varied from 2.92 +/- 0.15 cpm (mean +/- SD) at mid-day to 2.72 +/- 0.13 cpm in the late night. CONCLUSIONS: Ambulatory recording of electrogastrography needs technical improvement. The electrogastrogram shows a circadian variation in frequency.
BACKGROUND: Development of electrogastrography, the recording of gastric electric rhythm from cutaneous electrodes, for clinical purposes has been hampered by methodologic problems and the lack of an ambulatory technique. We have evaluated a newly developed system for ambulatory electrogastrography. METHODS: 24-Hour recordings were obtained from 30 healthy volunteers. We used digital filtering, a Hamming window, and spectral analysis to determine the dominant frequency of successive 256-sec segments of data. RESULTS: Low-frequency noise disturbed the primary signal. After secondary filtering a stable normogastric (2-4 cpm) rhythm was present during a median of 49% (range, 34-79%) of the recording time. The mean frequency of gastric electric activity varied from 2.92 +/- 0.15 cpm (mean +/- SD) at mid-day to 2.72 +/- 0.13 cpm in the late night. CONCLUSIONS: Ambulatory recording of electrogastrography needs technical improvement. The electrogastrogram shows a circadian variation in frequency.