Paroxysmal brain state changes, such as microsleep events in drivers, are presumably subcortically induced and accompanied by cortical processes. This raises questions of how stable and persistent are the cortical processes that can be observed with EEG in real time. For this purpose, recordings of four night-driving simulation studies including 79...
Martin Patrick Pauli Constantin Pohl Martin Golz
Inter-individual differences in the feature distribution of electroencephalograms (EEG) during microsleep (MS) raise questions about the generalizability of the methodology, because methodology should have the same validity for subjects to be included in the analysis in the future as for subjects included so far. We address this question using leav...
Martin Patrick Pauli Constantin Pohl Martin Golz
GMLVQ (Generalized Matrix Relevance Learning Vector Quantization) is a method of machine learning with an adaptive metric. While training, the prototype vectors as well as the weight matrix of the metric are adapted simultaneously. The method is presented in more detail and compared with other machine learning methods employing a fixed metric. It w...
Martin Golz Sebastian Thomas Adolf Schenka
The circadian rhythm that drives the human sleepwake cycle manifests itself in the variation of the core body temperature (CBT). Measuring CBT continuously, however, is intricate. Heart rate and its variability also varies notably over the course of the day, but is more accessible to measure. We present first results from a study that investigates...
Christian Heinze Martin Golz
This paper examines the question of how strongly the spectral properties of the EEG during microsleep differ between individuals. For this purpose, 3859 microsleep examples were compared with 4044 counterexamples in which drivers were very drowsy but were able to perform the driving task. Two types of signal features were compared: logarithmic powe...
Martin Golz Adolf Schenka Florian Haselbeck Martin Patrick Pauli
Automatic relevance determination (ARD) was applied to two-channel EOG recordings for microsleep event (MSE) recognition. 10 s immediately before MSE and also before counterexamples of fatigued, but attentive driving were analysed. Two type of signal features were extracted: the maximum cross correlation (MaxCC) and logarithmic power spectral densi...
Martin Golz Sebastian Wollner David Sommer Sebastian Schnieder
It was investigated whether cognitive performance shows a circadian rhythm during a 50 h-long forced desynchrony sleep-wake-schedule. We asked whether it would be possible to estimate the circadian period of cognitive performance under such circumstances and how strong it correlates to subjective sleepiness rating as well as body temperature. Cogni...
Thomas Schnupp Christian Heinze Martin Golz
Automatic relevance determination (ARD) was applied to two-channel EOG recordings for microsleep event (MSE) recognition. 10 s immediately before MSE and also before counterexamples of fatigued, but attentive driving were analysed. Two type of signal features were extracted: the maximum cross correlation (MaxCC) and logarithmic power spectral densi...
Martin Golz Sebastian Wollner David Sommer Sebastian Schnieder
We examined if ECG-based features are discrimi-native towards drowsiness. Twenty-five volunteers (19–32 years) completed 7×40 minutes of monotonous overnight driving simulation, designed to induce drowsiness. ECG (512 s-1) was recorded continuously; subjective ratings of drowsiness on the Karolinska sleepiness scale (KSS) were polled every five min...
Christian Heinze Constantin Hütterer Thomas Schnupp Martin Golz
This contribution addresses the question if imminent changes of the cortical state are predictable. The analysis is based on 1484 examples of microsleep (MS) and 1940 counterexamples of sustained attention (SA), both observed during overnight driving in the simulator. EEG segments (8 s in length) immediately before each respective event were includ...
Martin Golz David Sommer Jarek Krajewski
Microsleep events (MSE) are short intrusions of sleep under the demand of sustained attention. They can impose a major threat to safety while driving a car and are considered one of the most significant causes of traffic accidents. Driver’s fatigue and MSE account for up to 20% of all car crashes in Europe and at least 100,000 accidents in the US e...
Gustavo Lenis Patrick Reichensperger David Sommer Olaf Dössel
EEG related sleepiness measures were investigated with regard to three hypotheses. Measures of sleepiness should increase with time since sleep as well as with time on task, and they should also increase shortly before a sleepiness related crash in the driving simulator occurs. For this purpose, power spectral densities in the alpha, theta and in t...
Martin Golz David Sommer Britta Geißler Axel Muttray
Recently, it has been shown by overnight driving simulation studies that microsleep density is the only known sleepiness indicator which rapidly increases within a few seconds immediately before sleepiness related crashes. This indicator is based solely on EEG and EOG and subsequent adaptive pattern recognition. Accurate microsleep recognition is v...
Martin Golz Adolf Schenka David Sommer A. Muttray
The purpose of this study was to refine a commercial car driving simulation for occupational research. As the effects of ethanol on driving behavior are well established, we choose alcohol as a test compound to investigate the performance of subjects during simulation. We programmed a night driving scenario consisting of monotonous highway and a ru...
Axel Muttray Anais Breitinger Elisabeth Goetze Stephan Letzel
An experimental sleep-wake protocol of 30-minute cycles with an allowed 10-minute sleep episode and an enforced 20-minute wake episode was carried out over 48 hours. The sleep and wake conditions of the experiment are simulated using the two process model. A fitness function measuring the occurrence of Non-REM sleep in the 10 minute episodes betwee...
Christian Heinze Sven Schirmer Udo Trutschel Martin Golz
Microsleep (MS) and alpha burst (AB) patterns in the EEG of ten young drivers were detected. Their percentage within 1 min intervals was compared with independent variables of drowsiness: 1) lane tracking performance, 2) self-rating of sleepiness. In addition, the occurrence of both patterns immediately before crashes was investigated. Results offe...
Martin Golz David Sommer
Based on questionnaires and diagnosis by one senior medical specialist 28 patients were evaluated with respect to their fall risk and categorized into two classes (low / high fall risk). Posturography stabilograms were quantitatively analyzed by means of time as well as spectral domain techniques. Feature sets were analyzed with three different met...
Thomas Schnupp Adolf Schenka L E Walther Martin Golz
Thomas Schnupp Adolf Schenka L Walther Martin Golz
Introduction Recently, two different methods were introduced to assess driver sleepiness based on pattern recognition in the EEG. One aims at machine learning to represent patterns occurring during microsleep events. Within the recall process the entire EEG is searched for microsleep-like patterns. The second method aims at detecting alpha burst ac...
Martin Golz David Sommer
In order to investigate the potential of heart rate measures to reflect changes in the circadian rhythm or in sleepiness, an ultrashort sleep-wake experimental protocol was used to unmask circadian- or sleepiness-related effects: Over a duration of 50 hours and always alternating, subjects attempted to fall asleep within 10 minutes and must stay aw...
Christian Heinze Udo Trutschel Martin Golz
Introduction Irregular sleep-wake behavior is common to a vast amount of people in industrialized nations. Many are working in shift schedules, other are travelling on long distant flights. Vigilance expert systems might be helpful managing sleep-wake behavior to become more regular. Mobile devices are needed to support adaptation of the expert sy...
David Sommer Martin Golz
Zusammenfassung Das Ziel des vorliegenden Beitrags ist die Darstellung der Entwicklung und Validierung eines phonetisch-akustischen Messverfahrens zur stimmbasierten Schläfrigkeitsdetektion. Der Vorzug dieses automatisierten Messansatzes liegt in der belästigungsarmen, sensorapplikationsfreien Handhabung. Das hier gewählte Stimmanalyseprozedere fol...
Jarek Krajewski Martin Sauerland David Sommer Martin Golz
Posturography methods have been applied in clinical neurootology to evaluate the equilibrium function of patients. Methods of statistical analysis play an important role for improving data processing and to support the interpretation of the results. In contrast to conventional statistics, artificial neural networks are model-free and non-parametric...
L E Walther I Repik Thomas Schnupp Martin Golz
The purpose of this study was to evaluate commercially available devices for driver fatigue monitoring with particular focus on the needs of the mining industry. We present an overview of fatigue monitoring technologies (FMTs) and propose means to evaluate the devices. Three video-based devices were selected and used in an overnight driving simulat...
Martin Golz David Sommer Udo Trutschel David J Edwards
The aim of this paper is to improve the information gained by the most commonly applied fit-for-duty sleepiness test (Pupillographic Sleepiness test, PST) by using pattern recognition approaches. The pupil diameter based sleepiness detection is enriched by several new features and machine learning methods. Using all newly computed pupil diameter fe...
Jarek Krajewski Thomas Schnupp Sebastian Schnieder Martin Golz
