A Suitable Approach in Extracting Non Event Related Potential Sources from Brain of Disabled Patients

Brain is the most important, astonishing and complicated part of human body which is responsible for controlling and functioning of all other human organs. The physical movements and thinking capability (Cognition) of humans depend on the brain activity. Based on certain changes that occur within the brain, electric fields will be generated within the brain. Analyzing brain signals plays vital role in diagnosis and treatment of brain disorders. Brain signals are obtained from electrodes of Electroencephalogram (EEG) or Magneto encephalogram (EMG). These are linear mixture of evoked potentials (EVP) of large number of neurons due to variations in conductive and geometric properties in the layers of 3 layer head model or 4 layer head model. Earlier work1-5 considered processing these mixed signals for analyzing brain functioning of brain disabled patients. But working on the source signals gives an authoritative result. Hence there is a need to separate the source signals from the measured (electrode) signals. This work will suggest a suitable approach in extracting source signals of disabled patients while they were used as subjects under experiment of retrieving event related potentials (ERP). This work retrieved the signals of non target trails i.e., non event related potentials (NERP) and extracted original source signals by the best Gaussian estimate and the algorithm proposed.