Pharmaco-EEG analysis by means of FFT and FAD.

The EEG effects of a single oral dose of diazepam, amitriptyline and pernazine were studied in 26 healthy volunteers. The EEG analysis was performed by means of FFT and a new parametric method FAD. The results indicate that the FAD method reveals drug changes significantly more often than does the FFT analysis and that the medication effects are more clearly defined by the FAD.

FAD-parametric description of EEG time series.

A new method of the EEG time series parametric description was elaborated. The procedure consists of the following steps: calculation of AR model coefficients, the estimation of the transfer function in the form of parallel filters, finding of the impulse response function parameters. The parameters: frequencies, amplitudes and damaging coefficients (FAD) characterise the basic EEG waves.

The EEG time series parametrization method in the study of nociception.

A new method of EEG time series parametrization was proposed. The EEG rhythms were described in terms of frequency, amplitude and damping. These parameters were used in multivariate analysis of variance in order to estimate the group differences in terms of Mahalanobis distances.

A new method of presentation of the average spectral properties of the EEG time series.

In framework of the AR model the transfer function and the impulse response function of the EEG time series were found. The parameters of the impulse response function were interpreted in terms of: frequencies, damping factors and amplitudes of the hypothetical brain rhythm generators. The method of the rhythm diagrams was proposed to describe the spectral properties of the EEG time series.

A study of stability of electrocortical rhythm generators.

By means of the autoregressive model the transfer function and the impulse response function were determined and the parameters characterizing electrocortical oscillators were found for the four brain structures of the experimental animals. Different kinds of the representation of these parameters were compared and their sensitivity to the different factors was tested. The advantages of the proposed method over the conventional spectral analysis were demonstrated.

Application of combined median-averaging filters to scintigraphic image processing.

Statistical and deterministic properties of median filters are briefly discussed and their inherent advantages as a prospective tool in scintigraphic data processing are pointed out. The ability of median filters of suppressing impulse noise while the edge-like features of an image are preserved, is demonstrated on phantom data. The residual high-frequency noise remaining after median filtering can be subsequently reduced by standard smoothing procedures.