A system for computer-assisted encoding, tabulation and analysis of visually scored sleep data is presented. The main features of the system are: (1) The use of computer-readable optical scan sheets for direct encoding of the sleep data. This eliminates the need for a separate transcription and/or key-punching operation. (2) The development of a visually scored data base, organized by NREM and ...

When a patient falls asleep, he transits by different sleep stages, which characterize the quality of his night. To determine these sleep stages, the technicians visually analyzes the polysomnographic signals (PSG) witch have different aspects according to these stages. However, this task requires a lot of time. This is why one generally tries to class them automatically. Then, one is generally...

Information processing has been suggested to depend on the current state of the brain as well as stimulus characteristics (e.g. salience). We compared processing of salient stimuli (subject's own names [SONs] and angry voice [AV] stimuli) to processing of unfamiliar names (UNs) and neutral voice (NV) stimuli across different vigilance stages (i.e. wakefulness as well as sleep stages N1 and N2) ...

Overnight sleep EEG recorded from 21 derivations was studied for 7 subjects (4 normal and 3 depressive). The multichannel autoregressive model was fitted to all 21 channels simultaneously. Ordinary, multiple and partial coherencies and directed transfer function were estimated for sleep stages and wakefulness. Ordinary coherencies give rather trivial information that coherence decreases with th...

BACKGROUND We investigate the potential usability of a novel in-the-ear electroencephalography recording device for sleep staging. METHODS In one healthy subject we compare simultaneous earelectroencephalography to standard scalp EEG visually and using power spectrograms. Hypnograms independently derived from the records are compared. RESULTS We find that alpha activity, K complexes, sleep ...

OBJECTIVE—Nocturnal hypoglycemia represents an important problem for diabetic patients, which has been primarily attributed to an attenuated hormonal counterregulation during sleep. So far, hypoglycemia counterregulation has been exclusively examined during early nocturnal sleep, although early sleep differs markedly in sleep stage architecture from late sleep. Here, we investigated whether awa...

In this study cyclic changes of human sleep structure were examined. For whole-night polysomnograms of 35 healthy volunteers of both sexes, manual hypnograms were created and divided into NREM-REM cycles. EEG signals from C3-A2 derivation were analysed by computer using a Fast Fourier Transform (FFT). For consecutive NREM-REM cycles of individual sleep stages, EEG power density contents for del...

Automated detection of waveforms such as delta and K-complex in the EEG is an important component of sleep stage monitoring. The K-complex is a key feature that contributes to sleep stages assessment. However, its automated detection is still difficult due to the stochastic nature of the EEG. In this paper, we propose a detection structure which can be interpreted as joint linear filtering oper...

To study the effects of neuroleptic therapy on sleep EEG variables in schizophrenia, as well as the clinical correlates of these variables, we performed polysomnographic (PSG) studies on 14 schizophrenic inpatients before and during neuroleptic therapy. Sleep continuity measures improved after 3 weeks of neuroleptic therapy, showing decreased sleep latency and improved sleep efficiency. REM lat...

The influence of afferent impulses of intestinal origin on the sleep stages was studied in fed and starved cats. Low-frequency electrical stimulation of the mucosal surface in a small intestinal fistula reduced the latency of sleep onset. The number of slow wave sleep episodes decreased, but their mean duration increased during stimulation. Conversely, the number of paradoxical sleep episodes i...