Enhanced Brain Source localization using Multimodal signal Fusion

A Master of Science thesis in Biomedical Engineering by Anas Chaari entitled, “Enhanced Brain Source localization using Multimodal signal Fusion”, submitted in December 2025. Thesis advisor is Dr. Hasan Al Nashash and thesis co-advisor is Dr. Hasan Mir. Soft copy is available (Thesis, Completion Cer...

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Main Author: Chaari, Anas (author)
Format: doctoralThesis
Published: 2025
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Online Access:https://hdl.handle.net/11073/33445
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author Chaari, Anas
author_facet Chaari, Anas
author_role author
dc.contributor.none.fl_str_mv Al Nashash, Hasan
Mir, Hasan
dc.creator.none.fl_str_mv Chaari, Anas
dc.date.none.fl_str_mv 2025-12
2026-05-21T15:38:33Z
2026-05-21T15:38:33Z
dc.format.none.fl_str_mv application/pdf
dc.identifier.none.fl_str_mv 35.232-2025.74
https://hdl.handle.net/11073/33445
dc.language.none.fl_str_mv en_US
dc.relation.none.fl_str_mv Master of Science in Biomedical Engineering (MSBME)
dc.subject.none.fl_str_mv Multimodal neuroimaging
Brain source localization
EEG Inverse problem
Joint EEG–fNIRS reconstruction
Neurovascular coupling
REML
dc.title.none.fl_str_mv Enhanced Brain Source localization using Multimodal signal Fusion
dc.type.none.fl_str_mv info:eu-repo/semantics/publishedVersion
info:eu-repo/semantics/doctoralThesis
description A Master of Science thesis in Biomedical Engineering by Anas Chaari entitled, “Enhanced Brain Source localization using Multimodal signal Fusion”, submitted in December 2025. Thesis advisor is Dr. Hasan Al Nashash and thesis co-advisor is Dr. Hasan Mir. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).
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identifier_str_mv 35.232-2025.74
language_invalid_str_mv en_US
network_acronym_str aus
network_name_str aus
oai_identifier_str oai:repository.aus.edu:11073/33445
publishDate 2025
repository.mail.fl_str_mv
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spelling Enhanced Brain Source localization using Multimodal signal FusionChaari, AnasMultimodal neuroimagingBrain source localizationEEG Inverse problemJoint EEG–fNIRS reconstructionNeurovascular couplingREMLA Master of Science thesis in Biomedical Engineering by Anas Chaari entitled, “Enhanced Brain Source localization using Multimodal signal Fusion”, submitted in December 2025. Thesis advisor is Dr. Hasan Al Nashash and thesis co-advisor is Dr. Hasan Mir. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The human brain is the most complex organ that controls multiple cognitive, sensory, and motor functions. Understanding its complex dynamics requires precise brain source localization techniques, which are important for diagnosing neurological disorders and studying brain functions. Multimodal neuroimaging can be applied to improve localization accuracy by combining modalities with complementary strengths of each modality. This project proposes an approach for multimodal brain source localization by integrating electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) data using Restricted Maximum Likelihood (REML) model to enhance both spatial and temporal accuracy. The methodology is validated using simulated data, where known neural sources were reconstructed independently using EEG and fNIRS, and then jointly using fNIRS-derived spatial priors. Integration reduced mean localization error (MLE) from 103.46 mm to 22.75 mm, showing the method’s accuracy. The proposed methodology was then applied to experimental data from 20 healthy subjects performing cognitive stress-induction tasks. EEG processing included filtering and ICA-based artifact removal, while fNIRS data underwent motion correction and detrending. The results showed consistent improvements across detection performance metrics, including specificity, accuracy, and MLE. For example, in Subject 10, MLE reduced from 72.601 mm (EEG only) to 16.010 mm (integrated), alongside improvements in specificity (0.3359 to 0.9883) and accuracy (0.3373 to 0.9873). A novel contribution of this work is the inclusion of neurovascular coupling delay compensation prior to multimodal integration, where EEG data are time shifted relative to hemodynamic responses in 2 s increments from 3 to 21 s. Optimal alignment was achieved between 3–5 s, showing enhanced localization performance. Additionally, analysis using frontal-only EEG channels to match the fNIRS cap layout im- proved spatial constraint and reduced interference from unrelated cortical regions.College of EngineeringMultidisciplinary ProgramMaster of Science in Biomedical Engineering (MSBME)Al Nashash, HasanMir, Hasan2026-05-21T15:38:33Z2026-05-21T15:38:33Z2025-12info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdf35.232-2025.74https://hdl.handle.net/11073/33445en_USMaster of Science in Biomedical Engineering (MSBME)oai:repository.aus.edu:11073/334452026-06-09T05:40:57Z
spellingShingle Enhanced Brain Source localization using Multimodal signal Fusion
Chaari, Anas
Multimodal neuroimaging
Brain source localization
EEG Inverse problem
Joint EEG–fNIRS reconstruction
Neurovascular coupling
REML
status_str publishedVersion
title Enhanced Brain Source localization using Multimodal signal Fusion
title_full Enhanced Brain Source localization using Multimodal signal Fusion
title_fullStr Enhanced Brain Source localization using Multimodal signal Fusion
title_full_unstemmed Enhanced Brain Source localization using Multimodal signal Fusion
title_short Enhanced Brain Source localization using Multimodal signal Fusion
title_sort Enhanced Brain Source localization using Multimodal signal Fusion
topic Multimodal neuroimaging
Brain source localization
EEG Inverse problem
Joint EEG–fNIRS reconstruction
Neurovascular coupling
REML
url https://hdl.handle.net/11073/33445