Search results for "EEG"
showing 10 items of 313 documents
EEG data acquisition system based on asynchronous sigma-delta modulator
2012
This paper describes a multichannel mobile EEG data acquisition system that consists of on-head sensors with built in electroencephalogram (EEG) signal amplifier, asynchronous sigma-delta modulator (ASDM) for analog to digital conversion and 434MHz On-Off keying (OOK) wireless data transmitter. A prototype circuit has been designed and fabricated in a 11×16mm cylinder package. After receiving the signal, appropriate processing is applied in order to reconstruct the brain wave signals.
Smadzeņu viļņus analizējošas programmatūras izstrāde
2018
Piekļuve personālajām EEG ierīcēm pēdējos gados ir strauji augusi, radot interesi par to potenciālo pietietojumu smadzeņu – datora interfeisa izveidē. Šī pētniecības darba mērķis ir apkopot informāciju par to kā smadzenēs ģenerētu signālu ir iespējams pārveidot komandās ar kurām iespējams vadīt dažāda veida programmatūru. Darbā tiek pētīts kādus smadzeņu signālus ir iespējams pārvērst vadības komandās, kādi ir populārākie algoritmi šo signālu pārveidošanai un kādi smadzeņu – datora interfeisa veidi šobrīd ir pieejami programmatūras izstrādei. Tiek pievērsta uzmanība arī tam kāda ir personālo EEG ierīču kvalitāte un vai tā ir piemērota kvalitatīvai programmatūras vadībai.
Studying the Response of Drivers against Different Collision Warning Systems: A Review
2017
International audience; The number of vehicle accidents is rapidly increasing and causing significant economic losses in many countries. According to the World Health Organization, road accidents will become the fifth major cause of death by the year 2030. To minimize these accidents different types of collision warning systems have been proposed for motor vehicle drivers. These systems can early detect and warn the drivers about the potential danger, up to a certain accuracy. Many researchers study the effectiveness of these systems by using different methods, including Electroencephalography (EEG). From the literature review, it has been observed that, these systems increase the drivers' …
Which direction should I go? A quest for understanding the effect of TMS stimulus orientation on evoked responses
2023
The orientation of the electric field (E-field) induced by transcranial magnetic stimulation (TMS) plays a significant role in determining the magnitude of motor evoked potentials (MEP) and TMS-evoked potentials (TEP). However, fundamental mechanisms explaining the interaction of the induced E-field and the underlying neuronal populations are still largely unknown. We recently entered a quest to understand and describe neurophysiological and physical factors affecting the effect of the E-field orientation on the MEP and TEP. We developed a dual-coil TMS transducer capable of fast and accurate electronic control of the induced E-field orientation. With this transducer, we could scan the effe…
Real-Time Localization of Epileptogenic Foci EEG Signals: An FPGA-Based Implementation
2020
The epileptogenic focus is a brain area that may be surgically removed to control of epileptic seizures. Locating it is an essential and crucial step prior to the surgical treatment. However, given the difficulty of determining the localization of this brain region responsible of the initial seizure discharge, many works have proposed machine learning methods for the automatic classification of focal and non-focal electroencephalographic (EEG) signals. These works use automatic classification as an analysis tool for helping neurosurgeons to identify focal areas off-line, out of surgery, during the processing of the huge amount of information collected during several days of patient monitori…
Data-driven analysis of simultaneous EEG/fMRI reveals neurophysiological phenotypes of impulse control
2016
Response inhibition is the ability to suppress inadequate but prepotent or ongoing response tendencies. A fronto-striatal network is involved in these processes. Between-subject differences in the intra-individual variability have been suggested to constitute a key to pathological processes underlying impulse control disorders. Single-trial EEG/fMRI analysis allows to increase sensitivity for inter-individual differences by incorporating intra-individual variability. Thirty-eight healthy subjects performed a visual Go/Nogo task during simultaneous EEG/fMRI. Of 38 healthy subjects, 21 subjects reliably showed Nogo-related ICs (Nogo-IC-positive) while 17 subjects (Nogo-IC-negative) did not. C…
Absence Seizure Detection Algorithm for Portable EEG Devices
2021
Absence seizures are generalized nonmotor epileptic seizures with abrupt onset and termination. Transient impairment of consciousness and spike-slow wave discharges (SWDs) in EEG are their characteristic manifestations. This type of seizure is severe in two common pediatric syndromes: childhood (CAE) and juvenile (JAE) absence epilepsy. The appearance of low-cost, portable EEG devices has paved the way for long-term, remote monitoring of CAE and JAE patients. The potential benefits of this kind of monitoring include facilitating diagnosis, personalized drug titration, and determining the duration of pharmacotherapy. Herein, we present a novel absence detection algorithm based on the propert…
Effects of pulsed high-frequency electromagnetic fields on the neuroendocrine system.
1998
The influence of pulsed high-frequency electromagnetic fields emitted from a circularly polarized antenna on the neuroendocrine system in healthy humans was investigated (900 MHz electromagnetic field, pulsed with 217 Hz, average power density 0.02 mW/cm<sup>2</sup>). Nocturnal hormone profiles of growth hormone (GH), cortisol, luteinizing hormone (LH) and melatonin were determined under polysomnographic control. An alteration in the hypothalamo-pituitary-adrenal axis activity was found with a slight, transient elevation in the cortisol serum level immediately after onset of field exposure which persisted for 1 h. For GH, LH and melatonin, no significant effects were found under…
An augmented MFS approach for brain activity reconstruction
2017
Abstract Weak electrical currents in the brain flow as a consequence of acquisition, processing and transmission of information by neurons, giving rise to electric and magnetic fields, which can be modeled by the quasi-stationary approximation of Maxwell’s equations. Electroencephalography (EEG) and magnetoencephalography (MEG) techniques allow for reconstructing the cerebral electrical currents and thus investigating the neuronal activity in the human brain in a non-invasive way. This is a typical electromagnetic inverse problem which can be addressed in two stages. In the first one a physical and geometrical representation of the head is used to find the relation between a given source mo…
Rear-view mirror use, driver alertness and road type: An empirical study using EEG measures
2006
Abstract The use of rear-view mirrors has been suggested as a good behavioural indicator of driver alertness in traffic situations (Brookhuis, K. A., De Vries, G., & De Waard, D. (1991). The effects of mobile telephoning on driving performance. Accident Analysis and Prevention, 23 (4), 309–316). In general terms, drivers look in the mirrors to find information and adapt their driving to traffic variations. This paper aims to analyse the links between time variations in alertness—measured from EEG activity data—and the frequency of rear-view mirror use in a group of drivers, both on motorways and conventional roads. The results point to a direct relationship between alertness level and mirro…