Correlation of electrogastrography and bioelectric impedance techniques for the gastric motility assessment

The electrical bioimpedance (EBI) technique has been used to measure gastric motility and emptying parameters. A well-known technique for this purpose is electrogastrography (EGG). No correlation between EGG signal and mechanical motility has been reported. In this study, a direct data comparison of these two techniques was performed.

23 volunteers underwent simultaneous gastric monitoring using EGG and EBI. Signal processing was performed to isolate the slow waves of 0.5-9 cpm. The parameters obtained from 70 % overlapped time slots of 3.5 min, included the dominant frequency and power of the normo-gastric region and the percentage of brady-, normo-, and tachy-gastric slow waves.

The EGG showed slightly higher values in dominant frequencies, whereas EBI displayed higher variability. High-frequency features were more significant in the EBI, with lower variability, and correlations were found in approximately half of the frequency spectra. Slow waves exhibited poor correlation, but were significant at 95 % of the timeslots.

Comparing EBI and EGG, global parameters in the normogastric region had slight variances, which may not significantly impact clinical findings. The sensitivity of the EBI to higher frequencies is evident.