title: Peak detection of somatosensory evoked potentials using an integrated principal component analysis-walsh method.
abstract: Clinical application of somatosensory evoked potentials (SSEP) in intraoperative neurophysiological monitoring still requires anywhere between 200 to 500 trials, which is excessive and introduces a delay during surgery. In this study, the analysis was performed on the data recorded in 20 patients undergoing surgery during which the posterior tibial nerve was stimulated and SSEP response was recorded from scalp. The first 10 trials were analyzed using an eigen decomposition technique, and a signal extraction algorithm eliminated the common components of the signals not contributing to the SSEP. A unique Walsh transform operation was then used to identify the position of the SSEP event within the clinical requirements of 10% time in latency deviation and 50% peak-to-peak amplitude deviation using only 10 trials. The algorithm also shows consistency in the results in monitoring SSEP in up to 6-hour surgical procedures even under this significantly reduced number of trials.
authors.affiliation: Center for Advanced Technology and Education, College of Engineering and Computing, Florida International University, Miami, FL, USA.
authors.forename: Krishnatej
authors.initials: K
authors.lastname: Vedala
authors.forename: Ilker
authors.initials: I
authors.lastname: Yaylali
authors.forename: Mercedes
authors.initials: M
authors.lastname: Cabrerizo
authors.forename: Mohammed
authors.initials: M
authors.lastname: Goryawala
authors.forename: Malek
authors.initials: M
authors.lastname: Adjouadi
mesh_terms: D000465:Algorithms; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D006801:Humans; D016343:Monitoring, Intraoperative / Q000379:methods*; D025341:Principal Component Analysis / Q000379:methods*; D013979:Tibial Nerve / Q000502:physiology