[show abstract][hide abstract] ABSTRACT: A warning system capable of reliably detecting lapses in responsiveness (lapses) has the potential to prevent many fatal accidents. We have developed a system capable of detecting lapses in real-time with second-scale temporal resolution. Data was from 15 subjects performing a visuomotor tracking task for two 1-hour sessions with concurrent electroencephalogram (EEG) and facial video recordings. The detector uses a neural network with normalized EEG log-power spectrum inputs from two bipolar EEG derivations, though we also considered a multichannel detector. Lapses, identified using a combination of video rating and tracking behavior, were used to train our detector. We compared detectors employing tapped delay-line linear perceptron, tapped delay-line multilayer perceptron (TDL-MLP), and long short-term memory (LSTM) recurrent neural networks operating continuously at 1 Hz. Using estimates of EEG log-power spectra from up to 4 s prior to a lapse improved detection compared with only using the most recent estimate. We report the first application of a LSTM to an EEG analysis problem. LSTM performance was equivalent to the best TDL-MLP network but did not require an input buffer. Overall performance was satisfactory with area under the curve from receiver operating characteristic analysis of 0.84 plusmn 0.02 (mean plusmn SE) and area under the precision-recall curve of 0.41 plusmn 0.08
IEEE Transactions on Biomedical Engineering 06/2007; · 2.35 Impact Factor
[show abstract][hide abstract] ABSTRACT: In many high-risk occupations, it is critical that a person remains alert at all times. There is much to be gained by being able to monitor a person on-line and detect lapses of consciousness (LoC) so that remedial action can be taken (e.g., a rest break) to ensure that safety is maintained. In this study, 15 normal subjects were observed on two sessions while they performed a continuous tracking task for a period of 1 hour. EEG, eye movements, tracking performance data and a video of the subject were recorded during the session. This work presents some preliminary results on the phenomenon of lapsing. Only 4 of the 15 subjects did not have a LoC at some stage. Seven subjects had LoCs more than 45 times and 4 more than 100 times during the 2 hours. The mean rate of lapsing over all subjects was 29.1 LoC/h. In contrast, lapses in performance were caused by both lapses of consciousness (30.1%) and attention (69.9%). There was no correlation found between age of subject and number of lapses of consciousness.
Engineering in Medicine and Biology Society, 2004. IEMBS '04. 26th Annual International Conference of the IEEE; 10/2004