Frank Zanow

Phase slips arise from state transitions of the coordinated activity of cortical neurons which can be extracted from the EEG data. The phase slip rates (PSRs) were studied from the high-density (256 channel) EEG data, sampled at 16.384 kHz, of five adult subjects during covert visual object naming tasks. Artifact-free data from 29 trials were avera...

High-density electroencephalography (HD-EEG) is currently limited to laboratory environments since state-of-the-art electrode caps require skilled staff and extensive preparation. We propose and evaluate a 256-channel cap with dry multipin electrodes for HD-EEG. We describe the designs of the dry electrodes made from polyurethane and coated with Ag...

In state-of-the-art Electroencephalography (EEG) Silver/Silver-Chloride electrodes are applied together with electrolyte gels or pastes. Their application requires extensive preparation, trained medical staff and limits measurement time and mobility. We recently proposed a novel multichannel cap system for dry EEG electrodes for mobile and out-of-t...

Multichannel Electroencephalography (EEG) is widely used in clinical neurology and neuroscientific research. EEG caps with 64 wet Silver/Silver-Chloride (Ag/AgCl) electrodes represent an often-used standard in the field. Reproducible electrode-skin contact for these electrodes is ensured by electrolyte gel or paste. Thus, these electrodes require s...

Aim: Heat stress and hypoxia independently influence cerebrocortical activity and impair prolonged exercise performance. This study examined the relationship between electroencephalography (EEG) activity and self-paced exercise performance in control (CON, 18°C, 40% RH), hot (HOT, 35°C, 60%RH) and hypoxic (HYP, 18°C, 40%RH FiO2 : 0.145) conditions...

Transcranial Magnetic Stimulation (TMS) and Electroencephalography (EEG) are two of the most commonly used modalities to investigate signal propagation in the cortex and cognitive processes. As TMS provides a non-invasive and low-risk method to elicit/inhibit certain cognitive processes in the brain, it is a versatile tool, but as such, it depends...

Current usage of electroencephalography (EEG) is limited to laboratory environments. Self-application of a multichannel wet EEG caps is practically impossible, since the application of state-of-the-art wet EEG sensors requires trained laboratory staff. We propose a novel EEG cap system with multipin dry electrodes overcoming this problem. We descri...

Important requirements for the analysis of multichannel EEG data are efficient techniques for signal enhancement, signal decomposition, feature extraction, and dimensionality reduction. We propose a new approach for spatial harmonic analysis (SPHARA) that extends the classical spatial Fourier analysis to EEG sensors positioned non-uniformly on the...

Powered exoskeletons can empower paraplegics to stand and walk. Actively controlled hip ab/adduction (HAA) is needed for weight shift and for lateral foot placement to support dynamic balance control and to counteract disturbances in the frontal plane. Here, we describe the design, control, and preliminary evaluation of a novel exoskeleton, MINDWAL...

Neuroprosthetic technology and robotic exoskeletons are being developed to facilitate stepping, reduce muscle efforts, and promote motor recovery. Nevertheless, the guidance forces of an exoskeleton may influence the sensory inputs, sensorimotor interactions and resulting muscle activity patterns during stepping. The aim of this study was to report...

This paper presents MINDWALKER, which is an ambitious EC funded research project coordinated by Space Applications Services aiming at the development of novel Brain Neural Computer Interfaces (BNCI) and robotics technologies, with the goal of obtaining a crutch-less assistive lower limbs exoskeleton, with non-invasive brain control approach as main...

Background Mobile, wireless high-density biosignal applications are becoming more important in order to make the transition from a curative to a preemptive paradigm in medicine possible. State-of-the-art wet Ag/AgCl electrodes, although well established due to a superior signal performance, exhibit some well known drawbacks when used in high-densit...

New areas of application for electroencephalography are in brain-computer interfaces, where disabled people might be able to interact with their environment based on measured brain signals. However, conventional electroencephalography is not suitable here. Thus, our aim is to develop novel dry electrodes for home use. We developed various novel EEG...

Dry biosignal electrodes for electro-encephalography (EEG) are an essential step for realization of ubiquitous EEG monitoring and brain computer interface technologies. We propose a novel electrode design with a specific shape for hair layer interfusion and reliable skin contact. An electrically conductive Titanium-Nitride (TiN) thin layer is depos...

MINDWALKER [1] is an EC FP7 funded project which aims at researching, designing and prototyping technologies for the seamless control of a lower limbs exoskeleton, relying on BNCI (Brain Neural Computer Interfaces) technologies. It promotes a non-invasive approach minimizing the cognitive load of the user for controlling the system. This paper firs...

With up to 256 silver/silver-chloride (Ag/AgCl) electrodes, research using multichannel electroencephalography (EEG) is nowadays characterized by an increasing number of electrodes. Hence, the preparation gets more and more time-consuming and error-prone. We propose a novel electrode concept based on titanium/titanium nitride (Ti/TiN) electrodes in...

Usability of conventional wet electrodes for electroencephalography (EEG) is depending on a set of requirements, including time consuming and complex preparation of the skin of a subject, thus limiting possible application. A new class of “dry” electrodes without the need for electrolyte gels or pastes is being investigated. The dry application sce...

Chronic alcoholism leads to impaired visual and auditory processing of emotions, but the cross-modal (auditory-visual) processing of emotional stimuli has not yet been explored. Our objectives were to describe the electrophysiological correlates of unimodal (visual and auditory) impairments in emotion processing in people suffering from alcoholism,...

The purpose of this paper is to introduce a new method for spatial-time-frequency analysis of multichannel biomedical data. We exemplify the method for data recorded with a 31-channel Philips biomagnetometer. The method creates approximations and decompositions of spatiotemporal signal distributions using elements (atoms) chosen from a very large a...

A method for multichannel biomedical signal analysis was developed and is presented in this paper. The method is based on the Matching Pursuit algorithm. It creates approximations of spatiotemporal distributions of multichannel data using a relatively small number of components chosen from a very big and redundant set. The components are distribute...

Time-frequency signal analysis based on various decomposition techniques is widely used in biomedical applications. Matching Pursuit is a new adaptive approach for time-frequency decomposition of such biomedical signals. Its advantage is that it creates a concise signal approximation with the help of a small set of Gabor atoms chosen iteratively fr...

Sophisticated analysis methods for EEG and MEG play a key role in the better understanding of brain functions as measured by high-density EEG and MEG. Being commercially available since 1996, the ASA software (ANT Software BV, Enschede, Netherlands) has been gaining growing popularity among clinical and cognitive researchers. With the following art...

Sophisticated analysis methods for EEG and MEG play a key role in the better understanding of brain functions as measured by high-density EEG and MEG. Being commercially available since 1996, the ASA software (ANT Software BV, Enschede, Netherlands) has been gaining growing popularity among clinical and cognitive researchers. With the following art...

In MEG source reconstruction, the use of realistically shaped volume conductor models for the head is becoming more and more common. Among several approaches to solve the volume conduction problem numerically, the boundary element method (BEM) is usually preferred. The main reason for this is that most of the blurring effects of the head on MEG ari...

In our project we develop a new educational software tool for electrophysiology courses. It is designed to be suitable for biomedical and technical curricula where these courses are scheduled. The software provides support for the education of electrophysiology. The software focuses on the relations between physiological sources and the observable...

When biomagnetic and/or bioelectric measurements are used for the localization of electrical activity within the human body, mathematical models are needed that describe the electrical properties of the sources and the surrounding region, the so-called volume conductor. The sources can be described as arrangements of current dipoles. Commonly, the...

Inverse solution techniques based on electroencephalograph (EEG) measurements have become a powerful means of gaining knowledge about the functioning of the brain. A model of the head and a potential computation method are necessary to describe the EEG problem mathematically. The generation of realistically shaped three-compartment models of the he...