02869nas a2200301 4500008004100000022001400041245009000055210006900145260001200214300001400226490000700240520184800247653003402095653003002129653001802159653002702177653001102204653003202215100002902247700001902276700002602295700002502321700003202346700002502378700002102403700002102424856012202445 2020 eng d a1558-021000aEnhancing Communication for People in Late-Stage ALS Using an fNIRS-Based BCI System.0 aEnhancing Communication for People in LateStage ALS Using an fNI c05/2020 a1198-12070 v283 a

OBJECTIVE: Brain-computer interface (BCI) based communication remains a challenge for people with later-stage amyotrophic lateral sclerosis (ALS) who lose all voluntary muscle control. Although recent studies have demonstrated the feasibility of functional near-infrared spectroscopy (fNIRS) to successfully control BCIs primarily for healthy cohorts, these systems are yet inefficient for people with severe motor disabilities like ALS. In this study, we developed a new fNIRS-based BCI system in concert with a single-trial Visuo-Mental (VM) paradigm to investigate the feasibility of enhanced communication for ALS patients, particularly those in the later stages of the disease.

METHODS: In the first part of the study, we recorded data from six ALS patients using our proposed protocol (fNIRS-VM) and compared the results with the conventional electroencephalography (EEG)-based multi-trial P3Speller (P3S). In the second part, we recorded longitudinal data from one patient in the late locked-in state (LIS) who had fully lost eye-gaze control. Using statistical parametric mapping (SPM) and correlation analysis, the optimal channels and hemodynamic features were selected and used in linear discriminant analysis (LDA).

RESULTS: Over all the subjects, we obtained an average accuracy of 81.3%±5.7% within comparatively short times (< 4 sec) in the fNIRS-VM protocol relative to an average accuracy of 74.0%±8.9% in the P3S, though not competitive in patients with no substantial visual problems. Our longitudinal analysis showed substantially superior accuracy using the proposed fNIRS-VM protocol (73.2%±2.0%) over the P3S (61.8%±1.5%).

SIGNIFICANCE: Our findings indicate the potential efficacy of our proposed system for communication and control for late-stage ALS patients.

10aAmyotrophic Lateral Sclerosis10abrain-computer interfaces10aCommunication10aElectroencephalography10aHumans10aSpectroscopy, Near-Infrared1 aBorgheai, Seyyed, Bahram1 aMcLinden, John1 aZisk, Alyssa, Hillary1 aHosni, Sarah, Ismail1 aDeligani, Roohollah, Jafari1 aAbtahi, Mohammadreza1 aMankodiya, Kunal1 aShahriari, Yalda uhttps://www.neurotechcenter.org/publications/2020/enhancing-communication-people-late-stage-als-using-fnirs-based-bci02632nas a2200217 4500008004100000245012200041210006900163260001200232520184800244653004002092653003502132653004402167653001702211100002102228700002102249700001702270700002102287700002102308700002102329856006402350 2019 eng d00aAn exploration of BCI performance variations in people with amyotrophic lateral sclerosis using longitudinal EEG data0 aexploration of BCI performance variations in people with amyotro c05/20193 aObjective. Brain-computer interface (BCI) technology enables people to use direct measures of brain activity for communication and control. The National Center for Adaptive Neurotechnologies (NCAN) and Helen Hayes Hospital are studying long-term independent home use of P300-based BCIs by people with amyotrophic lateral sclerosis (ALS). This BCI use takes place without technical oversight, and users can encounter substantial variation in their day-to-day BCI performance. The purpose of this study is to identify and evaluate features in the electroencephalogram (EEG) that correlate with successful BCI performance during home use with the goal of improving BCI for people with neuromuscular disorders. Approach. Nine people with ALS used a P300-based BCI at home over several months for communication and computer control. Sessions from a routine calibration task were categorized as successful (≥70%) or unsuccessful (<70%) BCI performance. The correlation of temporal and spectral EEG features with BCI performance was then evaluated. Main Results. BCI performance was positively correlated with an increase in alpha-band (8-14 Hz) activity at locations PO8, P3, Pz, and P4; and beta-band (15-30 Hz) activity at occipital locations. In addition, performance was significantly positively correlated with a positive deflection in EEG amplitude around 220 ms at frontal mid-line locations (i.e., Fz and Cz). BCI performance was negatively correlated with delta-band (1-3 Hz) activity recorded from occipital locations. Significance. These results highlight the variability found in the EEG and describe EEG features that correlate with successful BCI performance during day-to-day use of a P300-based BCI by people with ALS. These results should inform studies focused on improved BCI reliability for people with neuromuscular disorders.10aamyotrophic lateral sclerosis (ALS)10aBrain-computer interface (BCI)10aLongitudinal Electroencephalogram (EEG)10aP300 speller1 aShahriari, Yalda1 aVaughan, Theresa1 aMcCane, Lynn1 aAllison, Brendan1 aWolpaw, Jonathan1 aKrusienski, Dean uhttps://iopscience.iop.org/article/10.1088/1741-2552/ab22ea