Artifact detection in neonatal EEG using unsupervised machine learning

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Perustieteiden korkeakoulu | Master's thesis
Ask about the availability of the thesis by sending email to the Aalto University Learning Centre oppimiskeskus@aalto.fi

Date

2017-04-03

Department

Major/Subject

Biomedical Engineering

Mcode

SCI3059

Degree programme

Master’s Programme in Life Science Technologies

Language

en

Pages

53+8

Series

Abstract

The neonatal electroencephalogram (EEG) is an important tool for assessing cortical activity in critically ill neonates. However, the EEG is often contaminated by artifacts such movement artifacts, electromyographic (EMG) artifacts from muscle activity and electrocardiographic (ECG) artifacts. These artifacts make visual inspection difficult and negatively influence the results of automated analysis. Even though several methods for automated neonatal EEG analysis have been developed, there is a significant lack of comprehensive artifact detection systems for the neonatal EEG. In this thesis, an automated artifact detection system based on a semi-supervised Gaussian mixture model (GMM) is presented. We examined the effects of feature set size, mixture number and the use of principal component analysis (PCA) as a pre-processor. Performance was assessed using the area under the receiver operating characteristic (AUC) and estimated using leave-one-patient-out cross-validation. The best-performing system was obtained with 23 features, 30 mixtures and no PCA (median AUC = 0.95, IQR: 0.83--0.99). EMG and movement artifacts were detected with the highest accuracy.

Description

Supervisor

Parkkonen, Lauri

Thesis advisor

Stevenson, Nathan

Keywords

EEG, artifact, Gaussian mixture model, classification, neonatal

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