Semi-Automatic Artifact Rejection Procedure based on Kurtosis, Renyi's Entropy and Independent Component Scalp Maps

Abstract— Artifact rejection plays a key role in many signal processing applications. The artifacts are disturbance that can occur during the signal acquisition and that can alter the analysis of the signals themselves. Our aim is to automatically remove the artifacts, in particular from the Electroencephalographic (EEG) recordings. A technique for the automatic artifact rejection, based on the Independent Component Analysis (ICA) for the artifact extraction and on some high order statistics such as kurtosis and Shannon’s entropy, was proposed some years ago in literature. In this paper we try to enhance this technique proposing a new method based on the Renyi’s entropy. The performance of our method was tested and compared to the performance of the method in literature and the former proved to outperform the latter. Keywords — Artifact, EEG, Renyi’s entropy, kurtosis, Independent Component Analysis. I . I NTRODUCTION RTIFACT rejection is a key topic in many signal processing applications, particularly in biomedical applications. When an artifact occurs during a signal recording, it generates some unwelcome signals that can be superimposed to the signals that we want to analyse, therefore it can undermine the results of the analysis. In this paper we focus on the artifact rejection from brain activity registrations, in particular we focus on the artifact rejection from Electroencephalography (EEG). EEG is a technique for monitoring the electrical activity of the brain: the brain cells communicate by producing tiny electrical impulses and, by means of some electrodes placed on the scalp over multiple areas of the brain, we can detect and record patterns of electrical activity. Some flat metal discs (electrodes) are applied in different positions on the scalp, these discs are held in places with a sticky paste, the electrodes are connected by wires to an amplifier and a recording machine. EEG is used to help to diagnose the presence and type of seizure disorders, to look for causes of confusion, and to evaluate head injuries, tumors, infections, degenerative diseases and metabolic disturbances that affect the brain. The occurrence of the artifacts can alter the analysis or completely obscure the EEG waves. Artifacts are disturbances caused by eye movement, eye blink, electrode movement, muscle activity, movements of the head, sweating, breathing, earth