Seizure states identification in experimental epilepsy using gabor atom analysis.

Background: Epileptic seizures evolve through several states, and in the process the brain signals may change dramatically. Signals from different states share similar features, making it difficult to distinguish them from a time series; the goal of this work is to build a classifier capable of identifying seizure states based on time-frequency features taken from short signal segments.

Methods: There are different amounts of frequency components within each Time-Frequency window for each seizure state, referred to as the Gabor atom density.

Identification of epilepsy stages from ECoG using genetic programming classifiers.

Objective: Epilepsy is a common neurological disorder, for which a great deal of research has been devoted to analyze and characterize brain activity during seizures. While this can be done by a human expert, automatic methods still lag behind. This paper analyzes neural activity captured with Electrocorticogram (ECoG), recorded through intracranial implants from Kindling model test subjects.

Multisensor system for isotemporal measurements to assess indoor climatic conditions in poultry farms.

The rearing of poultry for meat production (broilers) is an agricultural food industry with high relevance to the economy and development of some countries. Periodic episodes of extreme climatic conditions during the summer season can cause high mortality among birds, resulting in economic losses. In this context, ventilation systems within poultry houses play a critical role to ensure appropriate indoor climatic conditions.

Sensitivity of rheoencephalographic measurements to spatial brain electrical conductivity.

Rheoencephalography (REG) is impedance plethysmography applied to the head, and provides an indirect measurement of the pulsatility of the cerebral blood volume. To extend REG as a clinical and research tool, it is necessary to evaluate the sensitivity of REG measurement to local brain conductivity changes. By means of the analytical solution of a four-sphere geometrical model of the head, maps of impedance sensitivity were assessed for different electrode arrangements.

Identification of spike sources using proximity analysis through hidden Markov models.

Hidden Markov models have shown promising results for identification of spike sources in Parkinson's disease treatment, e.g., for deep brain stimulation.

Extraction of the intracranial component from the rheoencephalographic signal: a new approach.

The well-known inherent artifact on the rheoencephalogram (REG) caused by the pulsatility of the scalp blood flow left the REG out of the clinical practice. In fact, depending on the selected electrode arrangement, the measurement of the brain impedance changes time-locked with the heartbeat can be completely buried on that of the scalp. In this work, a novel mathematical method based on the physiological differences between the brain and scalp perfusions is proposed to extract the intracranial information from REG.

Spatiotemporal pattern of the extracranial component of the rheoencephalographic signal.

The use of rheoencephalography (REG) in the clinical practice to evaluate cerebral blood flow is conditional on the finding of a method for removing the extracranial interference caused by the scalp blood flow. To remove this undesirable influence, digital processing based on statistics could be an effective technique if the appropriate data model were applied. This paper focuses on the analysis of the spatiotemporal features of the extracranial REG component, by comparing its morphology and phase shift at several scalp sites.

Influence of the scalp thickness on the intracranial contribution to rheoencephalography.

In spite of the great efforts made by the scientific community, up to now there is no agreement about the rheoencephalography (REG) capability to reflect cerebral blood flow (CBF). Moreover, a standard procedure and the optimal electrode arrangement have not been established yet. In a previous study, we found, using a classical four-shell spherical model of the head and solving it by numerical methods that, theoretically, there could exist an electrode arrangement to register an REG II free of extracranial contribution.