Type

Journal Article

Authors

Chris Bleakley
Mary Fitzsimons
Kunjan Patel
Eric C.-P. Chua

Subjects

Computer Science

Topics
seizure detection user interaction line detection interactive machine learning subject specific adaptation surgical algorithms

Improved patient specific seizure detection during pre-surgical evaluation (2011)

Abstract Objective: There is considerable interest in improved off-line automated seizure detection methods that will decrease the workload of EEG monitoring units. Subject-specific approaches have been demonstrated to perform better than subject-independent ones. However, for pre-surgical diagnostics, the traditional method of obtaining a priori data to train subject-specific classifiers is not practical. We present an alternative method that works by adapting the threshold of a subject-independent to a specific subject based on feedback from the user. Methods: A subject-independent quadratic discriminant classifier incorporating modified features based partially on the Gotman algorithm was first built. It was then used to derive subject-specific classifiers by determining subject-specific posterior probability thresholds via user interaction. The two schemes were tested on 529 h of intracranial EEG containing 63 seizures from 15 subjects undergoing pre-surgical evaluation. To provide comparison, the standard Gotman algorithm was implemented and optimised for this dataset by tuning the detection thresholds. Results: Compared to the tuned Gotman algorithm, the subject-independent scheme reduced the false positive rate by 51% (0.23 to 0.11 h−1) while increasing sensitivity from 53% to 62%. The subject-specific scheme further improved sensitivity to 78%, but with a small increase in false positive rate to 0.18 h−1. Conclusions: The results suggest that a subject-independent classifier scheme with modified features is useful for reducing false positive rate, while subject adaptation further enhances performance by improving sensitivity. The results also suggest that the proposed subject-adapted classifier scheme approximates the performance of the subject-specific Gotman algorithm. Significance: The proposed method could potentially increase the productivity of offline EEG analysis. The approach could also be generalised to enhance the performance of other subject independent algorithms.
Collections Ireland -> University College Dublin -> CASL Research Collection
Ireland -> University College Dublin -> Institutes and Centres
Ireland -> University College Dublin -> Complex and Adaptive Systems Laboratory
Ireland -> University College Dublin -> College of Science
Ireland -> University College Dublin -> School of Computer Science
Ireland -> University College Dublin -> Computer Science Research Collection

Full list of authors on original publication

Chris Bleakley, Mary Fitzsimons, Kunjan Patel, Eric C.-P. Chua

Experts in our system

1
Chris Bleakley
University College Dublin
Total Publications: 105