title: An adaptive detector of genioglossus EMG reflex using Berkner transform for time latency measurement in OSA pathophysiological studies.
abstract: To investigate obstructive sleep apnea syndrome mechanisms, we developed a device to measure the surface electromyogram (EMG) time latency reflex of the genioglossus muscle stimulated by time and amplitude calibrated negative pharyngeal pressure drops. The reflex signals were found to be disturbed by transient signals that generate false alarms. Thus, to reduce false alarm occurrences we designed an adaptive multiscale method. Continuous wavelet transform (CWT) is widely used in biomedical signal event detection processes. The Berkner transform is an approximation of a CWT that is based on a hierarchical scheme similar to discrete wavelet transform. We used the Berkner transform to build a multiscale detector because it offers the possibility of maxima coefficients linkage that leads to good accuracy in reflex onset localization. As a contribution to this novel approach we used a reconstruction formula to develop an adaptive method for scale range determination in our surface EMG reflex detector. Finally, we characterized our detector in terms of accuracy and robustness, first on synthesized signals and second, on signals acquired on apneic patients and healthy subjects. Preliminary results showed a significant difference (p < 0.01) between the two populations regarding the genioglossus muscle mean latency time. These physiological findings may partly explain why the upper airway protective reflex occurring when a negative pressure is applied to the upper airway is ineffective in OSA patients, leading to pharyngeal collapse.
authors.affiliation: Laboratoire Techniques de l'Imagerie, de la Modélisation et de la Cognition, UMR-CNRS 5525, Joseph Fourier University, 38706 Grenoble, France. Pierre-Yves.Gumery@imag.fr
authors.forename: Pierre Yves
authors.initials: PY
authors.lastname: Guméry
authors.forename: Hervé
authors.initials: H
authors.lastname: Roux-Buisson
authors.forename: Sylvain
authors.initials: S
authors.lastname: Meignen
authors.forename: François Louis
authors.initials: FL
authors.lastname: Comyn
authors.forename: Maurice
authors.initials: M
authors.lastname: Dematteis
authors.forename: Bernard
authors.initials: B
authors.lastname: Wuyam
authors.forename: Jean Louis
authors.initials: JL
authors.lastname: Pépin
authors.forename: Patrick
authors.initials: P
authors.lastname: Lévy
mesh_terms: D000465:Algorithms; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004576:Electromyography / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010609:Pharyngeal Muscles / Q000294:innervation* / Q000503:physiopathology*; D011930:Reaction Time; D012018:Reflex; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000503:physiopathology*