Time-frequency quantification of the small bowel myoelectrical surface recording

The electroenterogram is the myoelectrical signal of the small bowel, and is the result of a permanent slow wave and series of spike bursts that are only present when a bowel contraction occurs. Previous studies showed that time-frequency (t-f) distributions of electroenterogram recorded on abdominal surface are a helpful tool in order to interpret and quantify bowel myoelectrical activity. The aim of this paper is to relate parameters derived from surface electroenterogram t-f analysis to internal motility index (IMI). Local energy and local frequency are calculated and quantified from Choi-Williams (CWD) and spectrogram (SP) of surface recordings. Energy and energy over two Hz of internal electroenterogram recordings are calculated for quantifying intestinal motility. Correlation between surface recording parameters and internal motility index is studied. Our results show that some parameters derived from the spectrogram of surface electroenterogram present high correlation coefficient values (higher than 0.6). However, negativity of CWD provokes low correlation of CWD parameters with IMI. Spectrogram is better for quantifying intestinal myoelectrical activity in order to indicate gut motility. Bowel contractile activity can be studied without the need of surgical intervention through t-f analysis of electroenterogram recorded on the abdominal surface.