An assembled electrogastrographic device to examine the meal effect on gastric slow wave

We have assembled an electrogastrographic device based on the main components of amplifiers, a band-pass filter, an analogue/digital converter, low band-pass digital filters and a personal computer. The analysis software uses autoregressive moving average modelling to compute the frequency of slow waves and uses fast Fourier transformation for power spectral computation. Twenty healthy young male volunteers were enrolled in the study to test meal-elicited responses of the slow wave. Subjects underwent a 15 min recording while fasting and then a standard breakfast, which included 250 mL milk and a cake with a total of 1.45 kj, was ingested within 5 min. The post-prandial 15 min recording was immediately resumed after the meal. A slight but significant increase in the frequency of slow waves was seen in post-prandial measurement (mean +/- s.d., 0.0506 +/- 0.0005 vs 0.0497 +/- 0.0005 Hz; P < 0.0001). Moreover, a significant enhancement of the power of slow waves was elicited following the meal (36.0 +/- 3.1 vs 27.6 +/- 3.1 dB; P < 0.0001). We conclude that this assembled electrogastrographic device is a reliable means of monitoring gastric myoelectrical activity because the phenomenon of post-prandial responses of slow waves in either frequency or power is well demonstrated.