- author = "Arturo Sotelo and Enrique Guijarro and Leonardo Trujillo and Luis N. Coria and Yuliana Martinez",
- title = "Identification of epilepsy stages from {ECoG} using genetic programming classifiers",
- journal = "Computers in Biology and Medicine",
- year = "2013",
- volume = "43",
- number = "11",
- pages = "1713--1723",
- month = nov,
- email = "leonardo.trujillo@tectijuana.edu.mx",
- keywords = "genetic algorithms, genetic programming, Epilepsy diagnosis, Classification",
- ISSN = "0010-4825",
-
URL = "
http://www.sciencedirect.com/science/article/pii/S001048251300231X",
-
DOI = "
doi:10.1016/j.compbiomed.2013.08.016",
- size = "11 pages",
-
abstract = "Objective: Epilepsy is a common neurological disorder,
for which a great deal of research has been devoted to
analyse and characterise brain activity during
seizures. While this can be done by a human expert,
automatic methods still lag behind. This paper analyses
neural activity captured with Electrocorticogram
(ECoG), recorded through intracranial implants from
Kindling model test subjects. The goal is to
automatically identify the main seizure stages:
Pre-Ictal, Ictal and Post-Ictal. While visually
differentiating each stage can be done by an expert if
the complete time-series is available, the goal here is
to automatically identify the corresponding stage of
short signal segments.
Methods and materials: The proposal is to pose the above task as a supervised classification problem and derive a mapping function that classifies each signal segment. Given the complexity of the signal patterns, it is difficult to a priori choose any particular classifier. Therefore, Genetic Programming (GP), a population based meta-heuristic for automatic program induction, is used to automatically search for the mapping functions. Two GP-based classifiers are used and extensively evaluated. The signals from epileptic seizures are obtained using the Kindling model of elicited epilepsy in rodent test subjects, for which a seizure was elicited and recorded on four separate days. Results: Results show that signal segments from a single seizure can be used to derive accurate classifiers that generalise when tested on different signals from the same subject; i.e., GP can automatically produce accurate mapping functions for intra-subject classification. A large number of experiments are performed with the GP classifiers achieving good performance based on standard performance metrics. Moreover, a proof-of-concept real-world prototype is presented, where a GP classifier is transferred and hard-coded on an embedded system using a digital-to-analogue converter and a field programmable gate array, achieving a low average classification error of 14.55percent, sensitivity values between 0.65 and 0.97, and specificity values between 0.86 and 0.94.
Conclusions: The proposed approach achieves good results for stage identification, particularly when compared with previous works that focus on this task. The results show that the problem of intra-class classification can be solved with a low error, and high sensitivity and specificity. Moreover, the limitations of the approach are identified and good operating configurations can be proposed based on the results.",
