A circumferentially-sensitive miniature pressure sensor for study of human esophageal motility

Manometric systems in current use for study of human esophageal motility consist of sensors with a restricted radial disposition. Since both upper and lower esophageal sphincters are asymmetrical structures, such sensors are not ideal for sphincteric pressure measurements. In this report, we describe a circumferentially sensitive sensor (MT) which consists essentially of a miniature transducer mounted within a sealed fluid-filled chamber, surrounded by a pressure-sensitive silastic diaphragm. This device is accurate and sensitive. It was compared in 10 young healthy men with a standard perfused catheter system (PC) composed of three catheters, whose side openings were at the same axial level, connected to external transducers. Pressures recorded from the lower esophageal sphincter were significantly higher with the MT than with the PC; and in the upper esophageal sphincter, the rapid pressure changes associated with deglutition were far more faithfully reproduced with the MT. Contractile pressures recorded after swallowing from the body of the esophagus were similar with the two systems, provided that catheters were perfused at a rapid rate (approximately 8 ml/min for each catheter). This preliminary evaluation indicates that this MT has significant advantages as compared with currently available systems.