Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Master of Science in Electrical Engineering (MSEE)

Document Type

Master's Thesis




Electrical and Computer Engineering

First Advisor

Dr. Jihye Bae


Refractory focal epilepsy is characterized by the presence of seizures that cannot be controlled via anti-seizure medications. For patients suffering from this form of epilepsy, accurate identification of the seizure onset zone is a crucial step for many modalities of treatment. Electrical source imaging (ESI) allows for estimation of the seizure onset zone from electroencephalography. EEG feature extraction is an important step that can impact the final accuracy of source estimates. This work provides a review of 23 ictal ESI studies and proposes a delta-focused ictal ESI methodology. Our proposed delta-focused ictal ESI is implemented across 33 refractory focal epilepsy patients over 63 recorded seizures, guided by neurophysiological evidence of delta oscillatory activity contributing to seizure activity. We use 3 different inverse solutions applied across 4 different time windows and 2 distinct levels of delta filtering. The resulting computational estimates are compared to clinical references to measure accuracy. We achieve > 80% localizing accuracy in both electrographically and clinically defined seizures. These results are comparable to other ictal ESI studies, suggesting that the introduced delta-focused ictal ESI can yield adequately localizing results. This accurate seizure onset localization may contribute to improved pre-surgical evaluation in interventional procedures for refractory focal epilepsy.

Digital Object Identifier (DOI)

Funding Information

This study was supported by the University of Kentucky's Undergraduate Engineering Research Fellowship and the Department of Electrical and Computer Engineering's Undergraduate Engineering Research Fellowship.

Available for download on Friday, May 02, 2025