A Robust and Self-Paced BCI System Based on a Four Class SSVEP Paradigm: Algorithms and Protocols for a High-Transfer-Rate Direct Brain Communication

In this paper, we present, with particular focus on the adopted processing and identification chain and protocol-related solutions, a whole self-paced brain-computer interface system based on a 4-class steady-state visual evoked potentials (SSVEPs) paradigm. The proposed system incorporates an automated spatial filtering technique centred on the common spatial patterns (CSPs) method, an autoscaled and effective signal features extraction which is used for providing an unsupervised biofeedback, and a robust self-paced classifier based on the discriminant analysis theory. The adopted operating protocol is structured in a screening, training, and testing phase aimed at collecting user-specific information regarding best stimulation frequencies, optimal sources identification, and overall system processing chain calibration in only a few minutes. The system, validated on 11 healthy/pathologic subjects, has proven to be reliable in terms of achievable communication speed (up to 70 bit/min) and very robust to false positive identifications

An immersive virtual reality platform to enhance walking ability of children with acquired brain injuries

Background: Acquired brain injury (ABI) may result in lifelong impairment of physical, cognitive, and psychosocial functions. Several rehabilitative treatments are often needed to support walking recovery, thus participantsâ\u80\u99 engagement becomes a crucial aspect, especially when patients are children. In the last few years, traditional physiotherapy (PT) has been flanked by innovative technologies for rehabilitation in the fields of robotics and Virtual Reality (VR). Preliminary results have shown interesting perspectives in the use of a VR system, the GRAIL (Gait Real-time Analysis Interactive Lab), in improving walk- ing abilities in a small group of children with ABI, although further insights are needed about its use as rehabilitative tool in the pediatric population. Objectives: To evaluate the efficacy of a rehabilitation treatment on a GRAIL system for the improvement of walking abilities, in a group of children suffering from ABI. Methods: 12 children with ABI (study group â\u80\u93 SG; mean age = 12.1 ± 3.8 years old) underwent a 10-session treatment with the GRAIL, an instrumented multi-sensor platform based on immersive VR for gait training and rehabilitation in engaging VR environments. Before (T0) and at the end of the treatment (T1), the participants were assessed by means of functional scales (Gross Motor Function Measure (GMFM), Functional Assessment Questionnaire (FAQ), 6-Minute Walk Test (6minWT) and the 3D-Gait Analysis, over ground (OGA) and on GRAIL (GGA). Results: All the participants completed the rehabilitative treatment. The functional evaluations showed an improvement in Gross Motor abilities (GMFM-88, p = 0.008), especially in standing (GMFM-D, p = 0.007) and walking (GMFM-E, p = 0.005), an increase of the endurance (6minWT, p = 0.002), and enhanced autonomy in daily life activities (FAQ, p = 0.025). OGA identified a significant decrease of the Gillette Gait Index for the impaired side and a general increase of symmetry. GGA showed improvements in spatiotemporal parameters and joints range of motion that moved towards normality and symmetry recovery. Conclusions: A 10-session treatment with GRAIL on children with ABI led to improvements in their walking abilities and enhanced their engagement during the training. This is desirable when long life impairments are faced and childrenâ\u80\u99s motor functions have to be regained and it supports the leading role that VR might have in the rehabilitation field

Detection of drug resistance mutations at low plasma HIV-1 RNA load in a European multicentre cohort study

Guidelines indicate a plasma HIV-1 RNA load of 500-1000 copies/mL as the minimal threshold for antiretroviral drug resistance testing. Resistance testing at lower viral load levels may be useful to guide timely treatment switches, although data on the clinical utility of this remain limited. We report here the influence of viral load levels on the probability of detecting drug resistance mutations (DRMs) and other mutations by routine genotypic testing in a large multicentre European cohort, with a focus on tests performed at a viral load <1000 copies/mL

Search for intermediate-mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo

International audienceIntermediate-mass black holes (IMBHs) span the approximate mass range 100−105 M⊙, between black holes (BHs) that formed by stellar collapse and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a binary merger of mass ∼150 M⊙ providing direct evidence of IMBH formation. Here, we report on a dedicated search of O3 data for further IMBH binary mergers, combining both modeled (matched filter) and model-independent search methods. We find some marginal candidates, but none are sufficiently significant to indicate detection of further IMBH mergers. We quantify the sensitivity of the individual search methods and of the combined search using a suite of IMBH binary signals obtained via numerical relativity, including the effects of spins misaligned with the binary orbital axis, and present the resulting upper limits on astrophysical merger rates. Our most stringent limit is for equal mass and aligned spin BH binary of total mass 200 M⊙ and effective aligned spin 0.8 at 0.056 Gpc−3 yr−1 (90% confidence), a factor of 3.5 more constraining than previous LIGO-Virgo limits. We also update the estimated rate of mergers similar to GW190521 to 0.08 Gpc−3 yr−1.Key words: gravitational waves / stars: black holes / black hole physicsCorresponding author: W. Del Pozzo, e-mail: [email protected]† Deceased, August 2020

Open data from the first and second observing runs of Advanced LIGO and Advanced Virgo

Advanced LIGO and Advanced Virgo are monitoring the sky and collecting gravitational-wave strain data with sufficient sensitivity to detect signals routinely. In this paper we describe the data recorded by these instruments during their first and second observing runs. The main data products are gravitational-wave strain time series sampled at 16384 Hz. The datasets that include this strain measurement can be freely accessed through the Gravitational Wave Open Science Center at http://gw-openscience.org, together with data-quality information essential for the analysis of LIGO and Virgo data, documentation, tutorials, and supporting software