Multichannel digital recording of intraluminal temperature in the upper gastrointestinal tract of man: techniques and analyses.

A recording system has been developed to measure intraluminal temperature changes from six sites simultaneously in the upper gastrointestinal tract at rates up to 10 Hz from each site. The temperature probe contains six type K thermocouples mounted in 14 French gauge orogastric tube. The data is logged, after digital conversion and signal multiplexing, onto disc storage by a dedicated microcomputer. The fluctuating temperature profile, defined as temperature spikes, has been subjected to novel computer analysis to allow definition of temperature load and dissipation within the oesophagus, stomach and duodenum. This system enables the effects of drinking and eating hot and cold foods on the physiological functions of the gastrointestinal tract to be studied accurately.