Computer analysis of prolonged lower oesophageal sphincter pressure recordings

The aim of the study was to validate a recently developed computer program for the analysis of prolonged recordings of lower oesophageal sphincter pre ssure. Thirty 1-hour stretches were selected from sets of 24-h pressure sig nals recorded from the pharynx, oesophagus, lower oesophageal sphincter (LO S) and stomach in 10 ambulant patients with gastrooesophageal reflux diseas e. Three experienced investigators visually analysed end-expiratory LOS pre ssures and transient lower oesophageal sphincter relaxations (TLOSRs), usin g published criteria. A computer program was developed for calculation of a n end-expiratory pressure curve and detection of TLOSRs using the same crit eria. Although the results showed an maximum deviation from the mean of 11. 1% and 14.8% for manually calculated LOS pressures and visually detected TL OSRs, respectively only 62.1% of the detected TLOSRs were detected by all t hree observers. LOS pressure as measured by the computer closely approximat ed the mean of the LOS pressures calculated by the three observers. Althoug h the total number of TLOSRs was comparable to that assessed by visual anal ysis, the computer detected only 46% of the TLOSRs detected by each observe r and 56.8% of the TLOSRs detected by all observers. It is concluded that a utomated calculation of end-expiratory LOS pressure is feasible and yields reliable results, whereas automated detection of TLOSRs could not be satisf actorily accomplished. Our study showed that improvement of computer algori thms for TLOSR detection is desirable. However, the previously described cr iteria for detection of TLOSRs are insufficiently precise; further refineme nt of these criteria will be necessary to reduce the large discrepancies be tween the outcome of detection of TLOSRs by computer and by humans, and to reduce the equally large discrepancies between the results of detection by different human observers.