Analysis and modelling of amplitude changes in human duodenal slow waves

Abstract
Regular amplitude variations have frequently been observed in the slow-wave electrical signals recorded from the human duodenum. The amplitude variations could be the result of amplitude modulation of a single frequency signal, or the result of the summation of two signals at different frequencies. Signals were recorded from the serosal surface of the human duodenum. Frequency analysis of the signals, using both Fast Fourier Transform and Auto-Regressive Modelling techniques, shows that the predominant cause of the amplitude variations is the summation of two signals. The implications that the results have for models of the electrical activity of the human duodenum are discussed, and it is shown that an estimate of the degree of electrical coupling between cells can be inferred.