The computer as referee in the analysis of human small bowel motility

Abstract

The aim of this study was to determine whether visual analysis of graphic records of small bowel motility is a reliable method of discriminating pressure events caused by bowel wall contraction from those of extraenteric origin and to compare this method with computerized analysis. Each of six independent observers was supplied with the same pair of records of 1 h of fasting diurnal duodenojejunal motility, acquired with a 3-channel ambulant data-logging system; one record included many artifacts due to body movement while the other did not. The observers were asked to identify and classify pressure events and to measure the duration and amplitude of "true" contractions. A computer program for on-line analysis is described; the algorithm was designed to overcome the problems of a variable baseline and sudden changes in pressure due to body movements that are unavoidable in prolonged recording from the small bowel of ambulant subjects. For regular contractions (phase III of migrating motor complex) there was good agreement between observers but not for irregular contractions, particularly when movement artifacts were abundant. When the observers were asked to repeat the analysis 6 mo later, there was poor agreement with their original identification of irregular contractions and artifacts. There was, however, good agreement between the computer analysis, which was totally reproducible, and the median decisions of the observer group; this agreement supports the validity of our computer algorithm. We conclude that computer analysis is not merely a valuable ergonomic aid for analysis of large quantity of data acquired in prolonged ambulatory monitoring, but also that, even for brief recordings, it provides a standard of reproducibility unmatched by "expert" inspection. Visual analysis is unreliable and thus susceptible to subjective bias; this may, in part, account for conflicting reports of small bowel motility under similar conditions reported by different workers in our own and other laboratories.

Multiple Intraluminal Impedance Measurement and Manometry in the Jejunum of Healthy Subjects: A New Tool for Diagnosis of Small Bowel Motility

“…The main reason for this restriction was poor interobserver agreement when evaluating short distance BTEs, because impedance recordings of the small bowel appear to be more affected by artifacts than in the esophagus. Similar difficulties have been encountered earlier by others [22] and by our own group [3] in the visual analysis of small bowel contractions. The restriction to MII events exceeding 10 cm in length in our present study is further substantiated by the validation study of Imam et al [12].…”

Comparison of the Small Bowel Motor Response to Solid and Liquid Meals in Man

“…A phase III was ignored if it occurred within 20 min after the start of ingestion of a drink or a meal, as conversion of interdigestive to postprandial motor pattern is not necessarily an immediate process [1,19]. A validated computer program calculated the incidence and amplitude of contractions as well as the AUC [5], Contractile activity was analyzed for the total period between the start of ingestion and the appearance of the next phase 111 and for consecutive 30-rnin intervals thereof. In one experi ment, a phase III was not seen within the 7-hour period after the liq uid meal and before the volunteer had his evening meal.…”

“…Recently, 24-hour ambulatory manometry has become available, now allowing prolonged recordings in ambula tory subjects [3,4], Furthermore different groups have developed dedicated computer softwares so that small bowel motor activity can be analyzed in greater detail [5][6][7][8], These new techniques now enable us to study the phys iology of postprandial small bowel motility in man.…”

Nitric oxide regulation of migrating motor complex: randomized trial of NG‐monomethyl‐l‐arginine effects in relation to muscarinic and serotonergic receptor blockade

“…Still, visual analysis is relevant to make fine discrimination between true contractions and artefacts. Other authors have shown computer-assisted interpretation of graphic records of small bowel motility to be a reliable method of discriminating pressure events caused by bowel wall contraction from those of extra-enteric origin, which is the main confounder in the analysis (Benson et al 1993). At present, no software is available that provides a fully automated small bowel manometry analysis.…”