Real-time display of the stomach slow wave and its parameters in a newly designed electrogastrographic system

We designed a new three-channel electrogastrographic (EGG) system, which wa s easily operated on the Windows 95 platform and could automatically provid e slow wave parameters. The purpose of the present study was to test its re liability and accuracy in clinical recording. The system included a signal acquisition device assembled on a printed circuit board. Recorded myoelectr ical signals were filtered, amplified, digitized, and transmitted via this device into a notebook personal computer (PC). Based on the shortterm Fouri er transform the software could transfer the time domain of the signal into the frequency domain. Real-time displayed slow wave parameters, including dominant frequency/power, percent of normal frequency (2-4 cpm), instabilit y coefficient in frequency/ power, and power ratio, were automatically rene wed every 64s. Twenty healthy subjects (M/F, 12/8; age, 23-51 years) were e nrolled to measure both fast and postprandial myoelectrical activities for each 30-min recording. Our results indicated that meal ingestion significan tly increased dominant frequency (3.15 +/- 0.20 vs 3.23 +/- 0.23 cpm; P < 0 .05) and power (26.1 +/- 3.8 vs 28.4 +/- 3.9 dB; P < 0.05). The power ratio of the meal effect was 2.02 +/- 2.07. Other parameters, including instabil ity coefficient and percent of normal frequency, remained similar despite f ood ingestion. This newly designed EGG system is acceptable for clinically measuring gastric myoelectrical activity; the real-time display of many EGG parameters is an advantage with this new system.