VERIFICATION OF THE INTRALUMINAL MULTIPLE ELECTRICAL-IMPEDANCE MEASUREMENT FOR THE RECORDING OF GASTROINTESTINAL MOTILITY

A new intraluminal electrical impedance procedure for high-resolution measurements and the quantitative assessment of gastrointestinal motil ity is examined in healthy volunteers by cineradiography and manometry . The peristalsis in the oesophagus, stomach and small bowel is record ed with a combined impedance-pressure catheter. Additionally, investig ations with a flexible 16-channel impedance catheter with a closed sur face and a diameter of 3 mm are carried out in the oesophagus and smal l intestine. The 16 measuring segments with a length of 2 cm each reco rd the contractile patterns from a 32-cm-long organ section without a gap. The correctness of the physical approach is validated by concurre nt impedance and cineradiography recordings of the oesophageal perista lsis. The comparative studies confirm a close relation between the pre ssure and the impedance changes in the oesophagus and small intestine. The time analysis of the impedance tracings offers information about the bolus transit and the change of the wall compliance along the orga n. Regions of high or low compliance of the muscular wall can be recog nized. From the impedance tracings the direction of the contraction wa ves as well as their velocities, lengths, beginnings and ends can be d etermined. Moreover, the beginning and end of the bolus, and from them the momentary bolus length, can be characterized for any instant duri ng the bolus transit.