Reference v intrakraniálním EEG: implementace a analýza

Abstract

PĹ™edstava záznamu mozkovĂ© aktivity bez zkreslujĂ­cĂ­ch artefaktĹŻ koluje ve vÄ›deckĂ˝ch kruzĂ­ch jiĹľ nÄ›kolik desĂ­tek let. ParazitnĂ­ jevy a nežádoucĂ­ sloĹľky dokáží vĂ˝raznÄ› komplikovat analĂ˝zu pacientskĂ©ho záznamu intrakraniálnĂ­ho elektroencefalografu (iEEG). S nástupem modernĂ­ technologie však zaÄŤaly pĹ™ibĂ˝vat novĂ© metody pro preciznĂ­ odstranÄ›nĂ­ zkreslujĂ­cĂ­ho šumu. Zde nastupuje koncept virtuálnĂ­ch referenÄŤnĂ­ch signálĹŻ, jakoĹľto nástroj pro eliminaci nežádoucĂ­ch komponent. V tĂ©to práci, metoda zaloĹľená na prĹŻmÄ›rovánĂ­ spolu s modernÄ›jšími metodami zaloĹľenĂ˝ch na analĂ˝ze nezávislĂ˝ch komponent (ICA) byly realizovány a testovány na rĹŻznĂ˝ch iEEG záznamech. Bylo zjištÄ›no, Ĺľe algoritmy zaloĹľenĂ© na ICA umoĹľĹujĂ­ lepší a pĹ™esnÄ›jší odhad referenÄŤnĂ­ho signálu v porovnánĂ­ s prĹŻmÄ›rovacĂ­ metodou. Na závÄ›r byly všechny navrĹľenĂ© metody implementovány do open-source Python knihovny đť‘źđť‘’đť‘“đť‘ đť‘–đť‘”, která je veĹ™ejnÄ› dostupná, jednoduše instalovatelná a pĹ™ipravena k pouĹľitĂ­.The idea of a artifact-free brain activity recording has been circling around the scientific world for a few decades. Parasitic phenomenons and unwanted components may significatntly complicate the analysis of intracranial electroencephalographic (iEEG) recordings. However, with the rise of modern technology, new methods for precise removal of noise artifacts started to emerge. Here we use the concept of virtual reference signals for the elimination of such unwanted components. In this work, the algorithms for reference signal estimation using common average based method as well as more recent methods based on independent component analysis (ICA) were realized and evaluated on a variety of iEEG data. It was found that the ICA-based algorithms allow obtaining more accurate estimation of the reference signal as compared to the average-based one. Finally, all the methods were implemented into a open-source Python package đť‘źđť‘’đť‘“đť‘ đť‘–đť‘”, which is publicly available, easy to install and ready to use.