Computerized 24-hour esophageal pH monitoring: a new ambulatory technique using radiotelemetry.

A computerized telemetric system using a portable microprocessor receiving unit has been designed for clinical use in ambulatory 24-hour esophageal pH monitoring. The receiving unit can be used with either a pH-sensitive radiotelemetry pill or a standard intraesophageal pH probe. Esophageal pH data is collected under microprocessor control while the patient is in the usual home or work environment. Computerized plotting and analysis of the compiled pH data is performed at the conclusion of the ambulatory testing. The system has been successfully used in patients with symptoms of esophageal reflux and healthy volunteers with no symptoms. The development of a computer-based radiotelemetry system for prolonged monitoring of esophageal pH represents a substantial advance in existing investigational technology. It allows the use of new radiotelemetric techniques of esophageal pH recording with increased patient comfort and acceptance over a 24-hour ambulatory testing period. Microprocessor control of both data collection and analysis allows rapid interpretation of complex 24-hour esophageal pH tracings and greatly facilitates the performance of esophageal pH monitoring as a routine clinical investigation.