Application of the directed transfer function method to the study of the propagation of epilepsy neural information.

A study of the propagation of electroencephalogram (EEG) activity before seizure by means of the Directed Transfer Function (DTF) is presented. The DTF method is a multi-channel parametric method of analysis based on an autoregressive model, and is capable of supplying such information as the direction, spectra and dynamics of the propagation of EEG signals. This method is typically utilized to determine patterns of neural information flow. In this paper, the DTF method is applied to detect the propagation of EEG signals, and the work is focused on aiding the clinical diagnose for the foci and the propagation pathway of the epilepsy neural information. The work has been efficiently utilized to diagnose complex partial seizures originating from temporal and frontal lobe structures in 10 patients, based on the intracranial recordings. It is concluded that the source of the seizure onset, as well as the neural circuitry, can be found so that the propagation of the epileptic information from the foci to the entire brain can be determined. It is tested that the DTF method may be effective and practical in the clinical diagnose.

A simulation for effects of RF electromagnetic radiation from a mobile handset on eyes model using the finite-difference time-domain method.

Finite-difference time-domain (FDTD) method and specific absorption rate (SAR) are employed here to study the relationship between the radiation of a mobile handset and the human being health. Nowadays, much more attention has been paid to the simulations for the effects of RF radiation on the particular organs, such as the eyes or the ears because they are more sensitive and more near to the working mobile. In the paper, the simulation of the RF fields is focused on the eyes model and the eyes with glasses of metal frame respectively. A planar inverted F antenna is used as an exposure source at 900 MHz. Under this case, the intensity of the electrical field is calculated and analyzed. Also, SAR is utilized to evaluate the absorption of the organs to the radiation. Through the simulation, the peak values of SAR per 1G tissue at the radiating power being 600mW are obtained. It is concluded that when people are wearing glasses of metal framework, the peak value of SAR is shown to be a little higher than the safety limits. It is suggested that the radiation from the mobile handset do more harmful effect on the eyes with the glasses of metal frameworks.

An understanding for the abnormal spikes of the EEG simulation in a 2-d neural network.

The work here presents an abnormal EEG simulation and an analysis for the abnormal spikes in the simulation by using the wavelet method. The simulation is derived from the electrophysiological model of an excitable neuron being in a disorder process. The spike wave and the multi-spike wave of the EEG morphology are reconstructed by step changes in the concentration of the intracellular calcium ions ([Ca]i). In the further work, when the concentration of [Ca] i is sufficiently large, the multi-spike wave can also be reconstructed and the spikes of the potentials are analyzed by the multi-layer wavelet method. The work will be helpful to understand how the EEG morphology is formed from the microcosmic viewpoint.