Characterization of sleep spindles using higher order statistics and spectra

Cataloged from PDF version of article.This work characterizes the dynamics of sleep spindles, observed in electroencephalogram (EEG) recorded from humans during sleep, using both time and frequency domain methods which depend on higher order statistics and spectra. The time domain method combines the use of second- and third-order correlations to reveal information on the stationarity of periodic spindle rhythms to detect transitions between multiple activities. The frequency domain method, based on normalized spectrum and bispectrum, describes frequency interactions associated with nonlinearities occuring in the observed EEG

Tremor recording and analysis as a tool for target localization in thalamotomy and DBS for tremor

The objective of this work was to design and use a tremor and analysis system for stereotactic thalamotomy and thalamus stimulation (DBS). A notebook PC based system was developed. The tremor was measured by accelero-transducers or EMG. The method was used to confirm the definitive localization of the coagulation or stimulation target. Intra-operatively recorded effects of stimulation on the tremor were reproducible. Thermocoagulation and electrode implantation were done only after a significant reduction of the tremor was recorded on thalamic stimulation between 75 and 125 Hz. This method has been used on 9 patients; 2 underwent DBS implantation. It is concluded that intra-operative monitoring of the tremor during ventrolateral thalamotomy or stimulation is useful for identifying the final target for coagulation or electrode implantation