Handling Unbalanced Data in Nocturnal Epileptic Seizure Detection using Accelerometers

Kris Cuppens, Peter Karsmakers, Anouk Van de Vel, Bert Bonroy, Milica Milosevic, Lieven Lagae, Berten Ceulemans, Sabine Van Huffel, Bart Vanrumste

Abstract

Data of nocturnal movements in epileptic patients is marked by an imbalance due to the relative small number of seizures compared to normal nocturnal movements. This makes developing a robust classifier more difficult, especially with respect to reducing the number of false positives while keeping a high sensitivity. In this paper we evaluated different ways to overcome this problem in our application, by using a different weighting of classes and by resampling the minority class. Furthermore, as we only have a limited number of training samples available per patient, additionally it was investigated in which manner the training set size affects the results. We observed that oversampling gives a higher performance than only adjusting the weights of both classes. Compared to its alternatives oversampling based on the probability density function gives the best results. On 2 of 3 patients, this technique gives a sensitivity of 95% or more and a PPV more than 70%. Furthermore, an increased imbalance in the dataset leads to lower performance, whereas the size of the dataset has little influence.

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Paper Citation


in Harvard Style

Cuppens K., Karsmakers P., Van de Vel A., Bonroy B., Milosevic M., Lagae L., Ceulemans B., Van Huffel S. and Vanrumste B. (2013). Handling Unbalanced Data in Nocturnal Epileptic Seizure Detection using Accelerometers . In Proceedings of the 2nd International Conference on Pattern Recognition Applications and Methods - Volume 1: ICPRAM, ISBN 978-989-8565-41-9, pages 447-452. DOI: 10.5220/0004264704470452


in Bibtex Style

@conference{icpram13,
author={Kris Cuppens and Peter Karsmakers and Anouk Van de Vel and Bert Bonroy and Milica Milosevic and Lieven Lagae and Berten Ceulemans and Sabine Van Huffel and Bart Vanrumste},
title={Handling Unbalanced Data in Nocturnal Epileptic Seizure Detection using Accelerometers},
booktitle={Proceedings of the 2nd International Conference on Pattern Recognition Applications and Methods - Volume 1: ICPRAM,},
year={2013},
pages={447-452},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0004264704470452},
isbn={978-989-8565-41-9},
}


in EndNote Style

TY - CONF
JO - Proceedings of the 2nd International Conference on Pattern Recognition Applications and Methods - Volume 1: ICPRAM,
TI - Handling Unbalanced Data in Nocturnal Epileptic Seizure Detection using Accelerometers
SN - 978-989-8565-41-9
AU - Cuppens K.
AU - Karsmakers P.
AU - Van de Vel A.
AU - Bonroy B.
AU - Milosevic M.
AU - Lagae L.
AU - Ceulemans B.
AU - Van Huffel S.
AU - Vanrumste B.
PY - 2013
SP - 447
EP - 452
DO - 10.5220/0004264704470452