Surface plasmons (SP) are collective excitations of the electron gas bounded to the interface between a surface plasmon active material and a dielectric. Such materials are characterized by a dominating contribution of the quasi-free electrons to the optical properties. In contrast to electron energy loss spectroscopy (EELS), surface plasmons are i...
M. Abraham M. Klopfleisch Martin Golz A. Tadjeddine
Short segments of EEG, EOG and pupil diame-ter signals recorded in overnight driving simulation ses-sions of 21 young subjects were extracted during micro-sleep events and during fatigue states, where driving is still possible. Both classes were found by video based subjec-tive scoring of experts. Estimated spectral power densities were used as inp...
Martin Golz David Sommer
Posturography is widely used for quantitative assessment of balance control function in patients with vestibular dysfunction. The objective of this study was to investigate whether the postural control of normal subjects is influenced by a medium dose of alcohol. 51 young volunteers without known vestibular diseases examined four 40-seconds trials...
Martin Golz David Sommer Leif Erik Walther
Für die individuelle Anpassung biomathematischer Modelle des menschlichen Schlaf-Wach-Zyklus ist es erforderlich, physiologische Größen zu messen, aus denen die freien Modellparameter abgeleitet werden können. Es ist bekannt, dass verschiedene Zeit- und Frequenzbereichs-Merkmale des Tachogramms deutliche zirkadiane Schwankungen aufweisen. Die zirka...
Christian Heinze Udo Trutschel David Sommer Martin Golz
Danilo Mandic Martin Golz Anthony Kuh Toshihisa Tanaka
Contradictory results of several authors which investigated the EEG immediately before and after stimulus presentation in order to evoke K-comple- xes (KC) during sleep have lead us to the question if methodological extensions in the biosignal ana- lysis can clarify the picture. We applied several methods of parametric and non-parametric power spec...
Martin Golz David Sommer Brigitte Kurella
The eye gaze point and the pupil size of five subjects were recorded during an overnight driving simulation task. By scoring the recorded videos clear microsleep events (MSE) and clear non-microsleep events were picked out and the measured signals in the preceding eight seconds were analyzed. The spectral power densities of these segments were clas...
Martin Golz David Sommer
EEG-signals and EOG-signals of eleven subjects were recorded during an overnight driving simulation task. By scoring the recorded videos clear microsleep events and clear non-microsleep events were picked out and small segments of the measured EEG- and EOG-signals before and during the events were analyzed. The spectral densities of these segments...
David Sommer Thilo Hink Martin Golz
Quantitative EEG analysis in combination with modern Soft Computing methods offers the feasibility of proces- sing a large amount of different features. This paper compares empirically the case of no feature reduction to four variants of feature reduction. Investigations were performed on a data set of more than 3,700 examples of microsleep events...
David Sommer Martin Golz
The alpha attenuation test was performed on 15 young subjects during one night in a driving simula- tion laboratory. Recorded electroencephalograms were analyzed by estimation of alpha attenuation coefficients and by neural networks to track the goal of discrimina- tion of fatigue states and drowsy states. Calculated alpha attenuation coefficients...
René Gerber David Sommer Martin Golz
Overnight driving is associated with increased accident risk due to impaired alertness and reduced performance. As a consequence of monotony and factors like time-of-day, time-since-sleep and time-on-task, fatigue is gener- ally increasing during driving. This increase is not always monotonically, but often shows slow waxing and wan- ing patterns,...
Martin Golz David Sommer
The Delay Vector Variance (DVV), as recently introduced in (1), describes a new approach for analysis of the linear and non-linear as well as the deterministic and stochastic character of a time series. It has been applied to different time series, such as polysomnography, heart rate variability and functional MRI. This paper briefly describes DVV...
Markus Holzbrecher Thomas Schnupp David Sommer Martin Golz
In diesem Beitrag werden einige Möglichkeiten zur Auswertung von Selbstorganisierenden Merkmalskarten für die Clusterung multivariater Merkmalsvektoren, die aus selektierten EEG Segmenten extrahiert wurden, vorgestellt. Da die übliche Auswertung der Gewinnhäufigkeiten in vielen Anwendungsfällen nicht eindeutig und instabil ist und außerdem eine Be...
David Sommer Martin Golz
Oculomotoric performance of 15 young sub- jects was measured under two different conditions during different states of fatigue. In a first task the subjects had to perform smooth pursuit eye movement and in a second task they had to hold eye fixations over 10 sec. Coordi- nates of point of gaze and pupil diameters were recorded by an eyetracking de...
Daniel Bauer David Sommer Martin Golz
The spectral powers of the pre-stimulus EEG are used as input feature vectors to Learning Vector Quantization and to Self-Organizing Map networks to classify these vectors into four classes. The four classes were observed in the EEG as eliciting patterns of K-complexes due to double-tone pip stimulations during sleep. A modified Learning Vector Qua...
Martin Golz David Sommer Thomas Lembcke Brigitte Kurella
Human postural equilibrium is the result of complex control processes. Nevertheless these processes are taken for granted in our daily life, disturbance or degeneration of a single system involved in these processes leads to a variety of diseases, which pile up with age. Therefore, investigation of postural signals is the aim of many clinical and b...
Andreas Fey David Sommer Martin Golz
The detection of spontaneous behavioral events like short episodes of unintentional sleep onset during driving, which are usually called microsleep events, still poses a challenge. The analysis of only a small number of signals seems to be useful to detect such events on a second-by-second basis. Here we present an experimental investigation of 22...
Martin Golz David Sommer Markus Holzbrecher Thomas Schnupp
Electrophysiological and eyetracking signals of eleven subjects recorded in overnight driving simulations were analyzed using three different neural networks: learning vector quantization, self-organizing maps and growing cell structures. In the first investigation the electrophysiological signals were screened for slow eye movements (SEM), a typic...
David Sommer Martin Golz
