New Approach to Estimation of Interchannel Phase Coupling of Electroencephalograms

Estimation of Inter-Channel Phase Synchronization of Eeg Signals in the Ridges of Their Wavelet Spectrograms in Patients With Traumatic Brain Injury

“…The approach to estimating the inter-channel phase connectivity of the EEG at the points of the ridges of their wavelet-spectrograms with the stationary phase is considered as an inverse task to the problem of modeling ridges. In [6] it is shown that for the amplitude and phase of the amplitudemodulated signal…”

“…We proposed an approach to the estimation of the inter-channel phase connectivity of the EEG [6] based on the phases calculation and comparison of the signals at the points of the ridges of their wavelet spectrograms having the property of stationarity of the phase, which does not exist in both of the above approaches. Under this the approach, phase-coupled pairs of EEG signals are considered for the group of healthy subjects and for the group of patients with traumatic brain injury during two cognitive and motor tests.…”

“…The coherency Coh xy (f) is determined by the normalized complex cross correlation of signals x and y: (2) In coherent analysis, due to the modulus of normalized complex cross correlation C xy (f) = 1, the coherency Coh xy (f) is averaged in different of time intervals and in a certain frequency interval that is determined using neurophysiological data. Normally, such intervals correspond to the delta (2-4 Hz), theta (4)(5)(6)(7)(8), and alpha (8-12 Hz) EEG rhythms. Such an averages and the presence of the threshold level of coherence that is used to select the phase-coupled…”

Investigation of distribution laws of the phase difference of the envelopes of electromyograms of antagonist muscles in Parkinson's disease and essential tremor patients

“…So, in the works of Yu.V. Obukhov and coauthors [14,15], the so-called "ridges" of wavelet spectrograms are used. The use of ridges allows to select the leading frequency in the signal, as well as to find signal areas with a high signal-tonoise ratio.…”

New Approach to the Detection of Epileptiform Activity in Eeg Signals and Methods to Differentiate Epileptic Seizures From Chewing Artifacts

“…IVAN A. KERSHNER, MIKHAIL V. SINKIN, YURI V. OBUKHOV where f r (τ k ) is the instantaneous frequency of the signal at the time τ k . Moreover, f r (τ k ) coincides with the frequency value at the point of the wavelet spectrogram ridge at the time τ k , if the following condition is satisfied[8]:…”