Abstract
Electrogastrography (EGG) is a non-invasive method but left unclear for clinical use. EGG was studied with the independent component analysis (ICA) for 5 volunteers, aged from 25 to 45 years. Four silver disc electrodes were set as a conventional placement; at the square corners on a frontal abdominal wall, referred to the center of the square (a navel). Electrocardiogram (ECG) was monitored and an impedance sensor was applied to the thorax to monitor the respiratory pattern. Signals were sampled at 250 Hz with a band-pass filter from 0.016 to 30 Hz (BIOTOP-6R12, San-ei, Japan), and digitalized into 14-bit. Subjects were supine position at rest with eyes-closed, and record EGG for 25 min. First five minutes, subjects were asked to be at rest, and following five minutes, subjects were asked to soak the left hand in cool water which was to be a cool water-load. The following five minutes were asked to take the hand out to be left at the room temperature. The cool water-load and being left at the room temperature were alternatively asked two times in total. Signals were analyzed with ICA (S. Makeig, USA). Four components were obtained; ECG, EGG, respiration and electromyograms were suspected. But, any other generators should be suspected from the abdominal signals than ECG, EGG, EMG and respiration. EGG with ICA needs further precise study in perspective. [Jpn J Physiol 55 Suppl:S190 (2005)]
