FARFAN Fernando Daniel
congresos y reuniones científicas
From bipolar to unipolar recordings
ALVARO GABRIEL PIZÁ; FERNANDO DANIEL FARFÁN; ANA LÍA ALBARRACÍN; GABRIEL ALFREDO RUIZ; CARMELO JOSÉ FELICE
Huerta Grande, Cordoba
Congreso; XXIX CONGRESO ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACION EN NEUROCIENCIAS; 2014
Sociedad Argentina de Investigación en Neurociencias
The recording techniques employed in electrophysiology laboratory influence the nature of the biosignals that are recorded during electrophysiological exploration processes. Unipolar recordings are useful for source localization during mapping procedures, but have a great susceptibility to far-field interferences that can obscure low-amplitude signals of interest. Bipolar recordings are standard in most laboratories because rejection of far-field signal facilitates identification of local potentials, but the signal of interest can be beneath either recording electrode. Here we have proposed calculation methods that allow to estimate the electrophysiological information of unipolar recordings from bipolar recordings. For this have been used two bipolar EEG recordings, e.g. C3-Pz and C4-Pz (with common active electrodes) to estimate the unipolar recordings of three channels (C3, C4 and Pz). Three techniques for solving linear equation systems were used: pseudo-inverse matrix, Tikhonov regularization and least squares. Unipolar recordings estimated with the proposed methods were statistically compared with real unipolar recordings both time- and frequency- domain. Preliminary results show the feasibility of obtaining unipolar recordings from bipolar recordings. The methodology proposed is versatile and can be used for a wide variety of electrophysiological applications.