“Analysis of EEG Recordings During Grasp and Lift (GAL) Trials

EEG stands for Electroencephalography is a medical technique that is used to
extract the signal in the brain by using a special medical device known as
electroencephalogram. EEG signal is highly noisy as the signal is recorded from a
scalp electrode that is influenced by different deeper brain structure. The changes of
the signal with time make the signal to be non-stationary. The idea of using the EEG
signal to extract the signals which related to object manipulation is reasonable as
most of the human cortex involves in basic motor tasks of a person. However, until
now there is uncertainty regarding what extent the extraction of signals from the
human brain can be used in the monitoring and control purposes. The purpose of
analysing this EEG data is to help develop a prosthetic device that can control an
upper limb and generate a power grasp or a pinch grasp involving the thumb and
index finger. Specifically for this project, we will focus on the process of analysing
the EEG signal that includes the extraction of data, filtering data, applying feature
extraction and performing classification of the EEG signal. This paper will review
the step by step process involved in this project which is to classify the 6 different
events or movement of grasping and lifting using the EEG recording of grasp and lift
trial. The classification of the signals is done by using various classifiers that
differentiate each of the 6 events and compute the percentage of accuracy for the
correctly predicted events. There are two types of investigation which are
classification with feature extraction and without feature extraction. Throughout this
project, we managed to get the classification accuracy of 6 events for 26.6% and 58.5%
while for 2 events of up to 67.4% and 96% using 6 channels for both algorithms
respectively.