Spatial Filtering of MEG Signals for User-Specified Spherical Regions

Oezkurt T. E., Sun M., Jia W., Sclabassi R. J.

IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, cilt.56, sa.10, ss.2429-2438, 2009 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 56 Sayı: 10
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1109/tbme.2009.2024760
  • Dergi Adı: IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.2429-2438
  • Anahtar Kelimeler: Biomagnetism, inverse problem, magnetoencephalography (MEG), signal space separation (SSS), source localization, spatial filtering, spherical harmonics, SPACE SEPARATION, RESPONSES, EEG
  • Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

We introduce a spatial filtering method in the spherical harmonics domain for constraining magnetoencephalographic (MEG) multichannel measurements to any user-specified spherical region of interest (ROI) inside the head. The method relies on a linear transformation of the signal space separation inner coefficients that represent the MEG signal generated by sources located inside the head. The spatial filtering is achieved effectively by constructing a spherical harmonics basis vector that is dependent on the center of the targeted ROI and it does not require any discrete division of the headspace into grids like the traditional MEG spatial filtering approaches. The validation and the performance of the method are demonstrated through both simulated and actual bilateral auditory-evoked data experiments.