Burst Patterns Occurring during Drowsiness in Clinical EEGs

Vigilance monitoring for operator safety: A simulation study on highway driving

INTRODUCTION

Alertness of individuals operating vehicles, aircrafts, and machinery is a pre-requisite for safety of the individual and for avoiding economic losses. In this paper, we present a new technique for determining the alertness level of the operator and elaborate the methodology for the specific case of highway driving

METHOD

Our hypothesis is that the time derivative of force exerted by the driver at the vehicle-human interfaces can be used to construct a signature of individual driving styles and to discern different levels of alertness

RESULTS

In this study, we present experimental results corroborating this hypothesis and introduce a parameter, 'spikiness index,' for the time series data of the force derivative to quantify driver alertness

IMPACT ON INDUSTRY

The low cost, ruggedness, and low-volume data processing requirements of the proposed technique give it a competitive edge over existing predominantly image processing based vigilance monitoring systems.

Sharp transients in the sleep EEG of healthy adults: a possible pitfall in the diagnostic assessment of seizure disorders

The use of sleep EEG recordings is a routine procedure in the diagnostic work up of patients with suspected epilepsy. With respect to the diagnostic significance of paroxysmal EEG phenomena it is of importance to be informed about the incidence of such paroxysms in EEG's of healthy subjects. Several benign paroxysmal EEG phenomena during drowsiness or sleep have been identified (benign epileptiform transients of sleep (BETS), 14 and 6 positive spikes). Recent studies have shown that other, apparently aspecific, paroxysmal sharp transients may be recorded during drowsiness or sleep in healthy subjects. In order to obtain more data on such paroxysmal EEG phenomena during sleep, a qualitative and semi quantitative analysis was performed on full night sleep recordings from 60 carefully selected healthy volunteers. Only 4 recordings were completely without the studied phenomena, all others showed some suspicious paroxysmal transients and some rare yet true specific epileptiform discharges were recorded in 8 subjects (13%), predominantly during transient periods of light non-REM sleep in the first two sleep cycles. The presence of some sharp transients during drowsiness or light sleep thus should be considered as a non-specific and non-pathological finding. Moreover these findings indicate the limited diagnostic specificity of the presence of a few epileptiform discharges during sleep, especially in patients with an ambiguous clinical history of epilepsy.