MS Thesis Defense
SAX-BOP: Epileptic Seizure Detection using
Symbolic Aggregate Approximation and Bag of Patterns
Sidharth Allani
1:00pm Friday, 12 December 2014, ITE 325b
Epilepsy is a chronic neurological disorder that makes patients susceptible to experiencing recurrent seizures. A seizure occurs when abnormal activity in the brain leads to involuntary body moment, lack of awareness or behavior, short-term loss of memory or attention, short-term unconsciousness, or body convulsions. Epilepsy affects three million people in the United States and accounts for $15.5 billion in direct and indirect costs.
Epilepsy has many different causes, and often no definite cause can be found. Patients who suffer from intractable seizures experience unpredictable and frequent seizures that cannot be controlled using anti-seizure drugs. Such seizures leave the patient traumatized and, due to their uncertainty, the patient’s mobility and independence are restricted, resulting in social isolation and economic hardship.
The research in this thesis aims to detect epileptic seizures and to analyze the performance of Symbolic Aggregate approXimation and the Bag of Patterns representation for seizure event detection. We use Electroencephalogram (EEG) recordings as the data source for seizure detection, which is the recording of electrical activity along the scalp that measures ionic current flows within the neurons of the brain. These signals are a good source of information about abnormal activity in the brain and are helpful in the process of epileptic seizure detection. This problem becomes challenging because of the enormous size of the EEG data, making it difficult to effectively and efficiently analyze these signals and detect a seizure. We use Symbolic Aggregate approXimation (SAX) and the Bag of Patterns Representation (BOP) and analyze their performance with EEG time series data to detect seizures.
Committee: Drs. Tim Oates (chair), Tim Finin and Tinoosh Mohsenin