title: Centre-specific multichannel electrogastrographic testing utilizing wavelet-based decomposition.
abstract: Although the principles of electrogastrography (EGG) have been known for years, the clinical utility of EGG has not been clearly demonstrated, and EGG recording and analysis techniques have not been fully standardized. The aim of this study was to develop a multichannel EGG technique for detecting abnormal gastric motility using an EGG database specifically designed for a particular testing centre, maximizing the sensitivity and the specificity of the test. Eight healthy volunteers formed a reference group to which 4 study groups (17 gastro-oesophageal reflux disease (GORD) patients, 7 functional dyspepsia patients, 8 post-fundoplication patients and 12 healthy volunteers) were compared. Eight-channel EGG was recorded in the postprandial and fasting states for 30 min each. The recorded signals were wavelet compressed and the resulting error (per cent root mean square difference (PRD)) after the compression was utilized to compare the study groups to the reference group. A threshold in the number of channels with significantly different PRD values was introduced. Sensitivity (SE), specificity (SP) and correct classification rate (CC) of the test in recognizing each clinical condition in the study groups for several channel thresholds and compressions were calculated, and were maximized. Increasing the compression and channel threshold levels improved the specificity, but decreased the sensitivity of the multichannel EGG test. An optimal combination region was identified based on a centre-specific adjustment of the channel threshold and the wavelet compression. The achieved maximum sensitivity, specificity and correct classification for this region in our test centre were as follows: GORD--SE 82.4%, SP 83.3%, CC 82.8%; functional dyspepsia--SE 100%, SP 75%, CC 84.2%; post-fundoplication--SE 75.0%, SP 83.3%, CC 80.0%. The utilization of a wavelet-based decomposition technique to process multichannel EGG signals can be a very effective method for enhancing the clinical utility of EGG, provided it is specifically developed for a given testing centre.
authors.affiliation: Department of Electrical and Computer Engineering, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
authors.forename: I V
authors.initials: IV
authors.lastname: Tchervensky
authors.forename: R J
authors.initials: RJ
authors.lastname: de Sobral Cintra
authors.forename: E
authors.initials: E
authors.lastname: Neshev
authors.forename: V S
authors.initials: VS
authors.lastname: Dimitrov
authors.forename: D C
authors.initials: DC
authors.lastname: Sadowski
authors.forename: M P
authors.initials: MP
authors.lastname: Mintchev
mesh_terms: D000328:Adult; D000368:Aged; D003938:Diagnostic Techniques, Digestive System / Q000706:statistics & numerical data; D004415:Dyspepsia / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D018662:Fundoplication; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D012680:Sensitivity and Specificity