I Computer-Aided Analysis of Human Esophageal Peristalsis Technical Description and Comparison with Manual Analysis DONALD O. CASTELL, MD, ANDRE DUBOIS, MD, PhD, CYNTHIA R. DAVIS, BS, CARMEL M. CORDOVA, BS, and DOUGLAS O. NORMAN, BS Manual and computer analysis of esophageal peristaltic activity induced by swallows of 5ml water were compared in 6 healthy subjects under basal conditions and following i.v. injection of 4 pharmacological agents: edrophonium (E, O.08mg/kg), atropine (A, 0.6rag), pentagastrin (PG, 0.6mcg/kg), and glucagon (GL, lmcg). Esophageal manomett7 was performed using a low compliance perfusion system and recorded on paper for standard manual analysis. The signal was concurrently taped on an analog recorder for subsequent digitization and analysis on a PDP-11 computer using a locally developed program. With both methods we determined the wave amplitude, duration, average upward slope (dP/ dT), and velocity of wave progyession. In addition, the computer allowed calculation of area under each wave and maximum upward slope (Max dP/dT). We found no significant difference between results of the parameters measured using both methods. Wave amplitude was significantly increased by E and significantly decreased by A. Average upward slope was decreased and velocity was significantly increased only by A. Computer-calculated wave area and Max dP/dT were significantly changed by both E and A. PG and GL had no effect on any of the measured parameters of the peristaltic wave. Esophageal peristalsis can be analyzed using a computer-aided method, providing a rapid and objective measurement of classical parameters and access to more in-depth analysis. Recording of pressure events during peristalsis in the human esophagus has been attempted for many years. Recent refinements in technology through Manuscript received September 6, 1982; revised manuscript received April 6, 1983; accepted April 12, 1983. From the Digestive Diseases Division, Department of Medi- cine, Uniformed Services University of the Health Sciences, and Computer Sciences Department, Armed Forces Radiobiology Research Institute, Bethesda, Maryland. The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Navy or the Department of Defense. The research reported herein was supported by USUHS grant R08316 and NNMC CIP 0-06-1398. Address for reprint requests: Dr. Donald O. Castell, Bowman Gray School of Medicine, 300 S. Hawthorne Rd., Winston- Salem, North Carolina 27103. the development of low-compliance, water-per- fused systems or direct intraesophageal transducers have allowed more accurate quantitative assess- ment of peristaltic pressure waves (1, 2). This has led to a clearer understanding of some specific clinical abnormalities of esophageal function and better description of other previously nonspecific abnormalities of peristalsis (3). Although measurement of esophageal peristalsis has been markedly improved by the recent techni- cal refinements, it still has important limitations. The popular method of manual reading of pressure tracings is subjective and tedious, requiring consid- erable technician and/or clinician time. In addition, manual readings are limited in their ability to pro- Digestive Diseases and Sciences, Vol. 29, No. I (January 1984) 65 0163-2116/84/01004)065503.50/0 1984 Plenum Publishing Corporation