Aplicação do tempo-frequência para a análise de sinais de eletroencefalográficos (EEG) no contexto de pacientes sob protocolo de morte encefálica

Abstract

This work proposes the quantitative analysis of electroencephalographic (EEG) signals, comparing normal subjects to patients in coma state under brain death protocol, by means of a software platform developed in MATLAB. This analysis involved peak frequencies, median frequencies, average, standard deviation and modular index. This last one relates to the bilaterality, i.e. how equidistant electrodes are on the same frequency. Results outlined that patients in coma present lower average median frequency (11.89 Hz), when compared to normal subjects (30.69 Hz). Moreover, with regard the analysis of bilaterality based on modular index, patients in coma also presented lower average standard deviation of the average median frequency (4.72 Hz) than the normal individuals (13 , 67 Hz), e.g., comatose patients presented higher bilaterality. Therefore, results suggests the possibility of applying these quantifications as biomarkers of brain death.