TY - JOUR
T1 - Brain chirps
T2 - Spectrographic signatures of epileptic seizures
AU - Schiff, Steven J.
AU - Colella, David
AU - Jacyna, Gary M.
AU - Hughes, Elizabeth
AU - Creekmore, Joseph W.
AU - Marshall, Angela
AU - Bozek-Kuzmicki, Maribeth
AU - Benke, George
AU - Gaillard, William D.
AU - Conry, Joan
AU - Weinstein, Steven R.
N1 - Funding Information:
Research supported by grants from grants from National Institutes of Health (7K02MH01493, 2R01MH50006) and U.S. Office of Naval Research (N00014-95-1-013). Software support was received from the MathWorks and Manugistics. AM received support from a WT Gill Jr Fellowship from the George Washington University School of Medicine.
PY - 2000/6/1
Y1 - 2000/6/1
N2 - Objective: A chirp is a brief signal within which the frequency content changes rapidly. Spectrographic chirps are found in signals produced from many biological and physical phenomena. In radar and sonar engineering, signals with chirps are used to localize direction and range to the signal source. Although characteristic frequency changes during epileptic seizures have long been observed, the correlation with chirps and chirp technology seems never to have been made. Methods: We analyzed 19 404 s (1870 s of which were from 43 seizures) of intracranially (subdural and depth electrode) recorded digital EEG from 6 patients for the presence of spectral chirps. Matched filters were constructed from methods in routine use in non-medical signal processing applications. Results: We found that chirps are very sensitive detectors of seizures (83%), and highly specific as markers (no false positive detections). The feasibility of using spectral chirps as matched filters was demonstrated. Conclusions: Chirps are highly specific and sensitive spectrographic signatures of epileptic seizure activity. In addition, chirps may serve as templates for matched filter design to detect seizures, and as such, can demonstrate localization and propagation of seizures from an epileptic focus. Copyright (C) 2000 Elsevier Science Ireland Ltd.
AB - Objective: A chirp is a brief signal within which the frequency content changes rapidly. Spectrographic chirps are found in signals produced from many biological and physical phenomena. In radar and sonar engineering, signals with chirps are used to localize direction and range to the signal source. Although characteristic frequency changes during epileptic seizures have long been observed, the correlation with chirps and chirp technology seems never to have been made. Methods: We analyzed 19 404 s (1870 s of which were from 43 seizures) of intracranially (subdural and depth electrode) recorded digital EEG from 6 patients for the presence of spectral chirps. Matched filters were constructed from methods in routine use in non-medical signal processing applications. Results: We found that chirps are very sensitive detectors of seizures (83%), and highly specific as markers (no false positive detections). The feasibility of using spectral chirps as matched filters was demonstrated. Conclusions: Chirps are highly specific and sensitive spectrographic signatures of epileptic seizure activity. In addition, chirps may serve as templates for matched filter design to detect seizures, and as such, can demonstrate localization and propagation of seizures from an epileptic focus. Copyright (C) 2000 Elsevier Science Ireland Ltd.
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U2 - 10.1016/S1388-2457(00)00259-5
DO - 10.1016/S1388-2457(00)00259-5
M3 - Article
C2 - 10825700
AN - SCOPUS:0034213032
SN - 1388-2457
VL - 111
SP - 953
EP - 958
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
IS - 6
ER -