Electroencephalography-guided upper-limb hybrid robotic platform to modulate cortical excitability

This study present an intervention combining an electroencephalography-based brain computer interface with a hybrid robotic system for the modulation of the cortical excitability (plasticity). Plasticity is intended to be elicited through the association of the voluntary motor-related cortical processes with the hybrid assistance during the execution of reaching movement. The cortical excitability was assessed before and after the intervention measuring the peak-to-peak amplitude of the Motor Evoked Potentials (MEPs) induced through transcranial magnetic stimulation pulses. Five healthy subjects participated in the experiments. Results showed an overall and distributed increase in the cortical excitability as a result of the proposed intervention

A hybrid automata framework for an adaptive impedance control of a robot-assisted training system

There is an increasing demand for an effective and adaptive robot-assisted training system for traumatic brain injury patients which can considerably promote their sensorimotor control performance, apart from ensuring the safety of the patients. This study focuses on the impedance control framework to simultaneously track the position trajectory while regulating the apparent impedance of the robot. The framework is based on the hybrid automata model that is used to govern the desired trajectory deployed by the robot-assisted training in assisting rehabilitative motion. A designed experimental setup was developed to evaluate the performance of the proposed hybrid automata scheme. Preliminary simulation results demonstrated the excellent response of the proposed framework with its ability to track the desired trajectory as well as the varying patients’ arm impedance profile. © Springer Nature Singapore Pte Ltd. 2020

Feedback-error learning control for powered assistive devices

Active orthoses (AOs) are becoming relevant for user-oriented training in gait rehabilitation. This implies efficient responses of AO's low-level controllers with short time modeling for medical applications. This thesis investigates, in an innovative way, the performance of Feedback-Error Learning (FEL) control to time-effectively adapt the AOs' responses to user-oriented trajectories and changes in the dynamics due to the interaction with the user. FEL control comprises a feedback PID controller and a neural network feedforward controller to promptly learn the inverse dynamics of two AOs. It was carried out experiments with able-bodied subjects walking on a treadmill and considering external disturbances to user-AO interaction. Results showed that the FEL control effectively tracked the user-oriented trajectory with position errors between 5% to 7%, and with a mean delay lower than 25 ms. Compared to a single PID control, the FEL control decreased by 16.5% and 90.7% the position error and delay, respectively. Moreover, the feedforward controller was able to learn the inverse dynamics of the two AOs and adapt to variations in the user-oriented trajectories, such as speed and angular range, while the feedback controller compensated for random disturbances. FEL demonstrated to be an efficient low-level controller for controlling AOs during gait rehabilitation.This work has been supported in part by the Fundação para a Ciência e Tecnologia (FCT) with the Reference Scholarship under Grant SFRH/BD/108309/2015, and part by the FEDER Funds through the Programa Operacional Regional do Norte and national funds from FCT with the project SmartOs - Controlo Inteligente de um Sistema Ortótico Ativo e Autónomo - under Grant NORTE-01-0145-FEDER-030386, and by the FEDER Funds through the COMPETE 2020—Programa Operacional Competitividade e Internacionalização (POCI)—with the Reference Project under Grant POCI-01-0145-FEDER-006941

Adaptive hybrid robotic system for rehabilitation of reaching movement after a brain injury: a usability study

BACKGROUND: Brain injury survivors often present upper-limb motor impairment affecting the execution of functional activities such as reaching. A currently active research line seeking to maximize upper-limb motor recovery after a brain injury, deals with the combined use of functional electrical stimulation (FES) and mechanical supporting devices, in what has been previously termed hybrid robotic systems. This study evaluates from the technical and clinical perspectives the usability of an integrated hybrid robotic system for the rehabilitation of upper-limb reaching movements after a brain lesion affecting the motor function. METHODS: The presented system is comprised of four main components. The hybrid assistance is given by a passive exoskeleton to support the arm weight against gravity and a functional electrical stimulation device to assist the execution of the reaching task. The feedback error learning (FEL) controller was implemented to adjust the intensity of the electrical stimuli delivered on target muscles according to the performance of the users. This control strategy is based on a proportional-integral-derivative feedback controller and an artificial neural network as the feedforward controller. Two experiments were carried out in this evaluation. First, the technical viability and the performance of the implemented FEL controller was evaluated in healthy subjects (N = 12). Second, a small cohort of patients with a brain injury (N = 4) participated in two experimental session to evaluate the system performance. Also, the overall satisfaction and emotional response of the users after they used the system was assessed. RESULTS: In the experiment with healthy subjects, a significant reduction of the tracking error was found during the execution of reaching movements. In the experiment with patients, a decreasing trend of the error trajectory was found together with an increasing trend in the task performance as the movement was repeated. Brain injury patients expressed a great acceptance in using the system as a rehabilitation tool. CONCLUSIONS: The study demonstrates the technical feasibility of using the hybrid robotic system for reaching rehabilitation. Patients’ reports on the received intervention reveal a great satisfaction and acceptance of the hybrid robotic system

Propiedades pulperas de E. globulus ssp globulus y E. grandis en las diferentes zonas de prioridad forestal.

De las especies de Eucalyptus plantadas en Uruguay E.grandis y E.globulus ocupan la mayor parte del área forestada con una superficie aproximada de 419.000 ha (150.000 y 269.000 has, respectivamente. MGAP, Dirección Forestal, 2004). Estas especies han mostrado diferente comportamiento en cuanto al grado deadaptación a las diferentes zonas en donde ha sido implantadas. Por un lado, el E.grandis, en general es una especie que alcanza valores relativamente altos de crecimiento en todo el país, particularmente en los departamentos de Tacuarembó y Rivera aunque también ha obtenido buenos niveles de productividad en las regiones del centro y litoral del pais. El E.globulus, sin embargo, es una especie que generalmente alcanza los mayores valores de crecimiento en la zona sureste seguidapor la zona del litoral oeste. En la región norte del país ha mostrado serios problemas de adaptación, lo cual está determinado fundamentalmente por la alta temperatura media anual. El Programa Nacional Forestal del INIA cuenta hoy en día con semilla de Huerto Semillero de 1ra y 2da generación para E. globulus y E. grandis,respectivamente, resultantes de la selección de los orígenes de mejor comportamiento en nuestro pais

Efecto de enfermedades del fuste en Eucalyptus globulus.

El alto valor de la madera de Eucalyplus globulus para la producción de pulpa y papel ha llevado a que esta especie sea, con más de 200 mil hectáreas, la especieforestal más plantada en Uruguay. En general se reconoce que E. globulus es una especie exigente desde el punto de vista climático y que es susceptible a diversas enfermedades y plagas. Sin embargo, tanto la adaptación a las diterentes zonas, como la susceptibilidad a enfermedades, varían marcadamente con la fuente de semilla utilizada. En el presente trabajo se analiza el efecto de enfermedades que afectan el fuste sobre el crecimiento y la capacidad de rebrote post cosecha, evaluado en un ensayo instalado en el departamento de Lavalleja

Performance of Eucalyptus tereticornis provenances in subtropical climate. [Comportamiento productivo de orígenes de Eucalyptus tereticornis en clima subtropical.]. [Comportamento produtivo de origens de Eucalyptus tereticornisem clima subtropical.]

ABSTRACT. - Eucalyptus tereticornis has a wide natural geographic distribution from Papua New Guinea to South Australia (6º-38º S), therefore, it is expected the existence of important differences among provenances. Although differ-ences in performance among provenances have been reported in several countries, the existing information is insufficient to allow the choice of the most appropriate provenance as a source of seeds for commercial planta-tions for humid subtropical climates. In order to evaluate the performance of 20 provenances of E. tereticornisin Uruguay and to generate information that contributes to the identification of the best provenances for humid subtropical climates, survival, individual tree volume, stem straightness and forking were assessed at 9-years-old in 4 sites in the center, north and northeast of Uruguay. Significant differences among provenances for all traits and significant provenance by site interaction for survival, individual tree volume and forking were found. No provenance was best in all sites. The Buckenbowra provenance had simultaneously high volume and sur-vival. The absence of a clear regionalization, coupled with a significant provenance-by site interaction, suggests that local evaluation of different provenances is essential to identify appropriate seed sources, both for tree breeding and for use in commercial plantations..-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.RESUMEN. - Eucalyptus tereticornis es una especie que tiene una amplia distribución geográfica natural, desde Papúa Nueva Guinea hasta Australia del Sur (6º-38º S), por lo tanto, es esperable la existencia de importantes diferencias entre procedencias. Aunque se han reportado diferencias en el rendimiento entre procedencias en varios paí-ses, la información existente es insuficiente para permitir la elección de la procedencia más apropiada como fuente de semillas para plantaciones comerciales en climas subtropicales húmedos. Para evaluar el desempeño de 20 procedencias de E. tereticornis en Uruguay y generar información que contribuya a la identificación de las mejores procedencias en climas subtropicales húmedos se evaluó supervivencia, volumen individual, recti-tud del fuste y presencia de bifurcaciones a los 9 años de edad, en 4 sitios en el centro, norte y noreste de Uruguay. Como resultado, se encontraron diferencias significativas entre procedencias para todas las caracte-rísticas y significativa interacción sitio por procedencia para supervivencia, volumen individual y presencia de bifurcaciones. Ninguna procedencia fue mejor en todos los sitios. La procedencia de Buckenbowra tuvo simul-táneamente un alto volumen y supervivencia. La ausencia de una clara regionalización, junto con una interac-ción significativa de procedencia por sitio, sugiere que la evaluación local de las diferentes procedencias es esencial para identificar las fuentes de semillas apropiadas para el cultivo de esta especie y su uso en planta-ciones comerciales..-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.RESUMO. - Eucalyptus tereticornis é uma espécie que apresenta ampla distribuição natural, desde Papua Nova Guiné até o Sul da Austrália (6º-38º S), portanto, espera-se a existência de diferenças importantes entre procedências. Embora diferenças de rendimento entre procedências tenham sido relatadas em vários países, as informações existentes são insuficientes para permitir a escolha da procedência mais apropriada como fonte de sementes para plantações comerciais em climas subtropicais úmidos. Para avaliar o desempenho de 20 procedências deE. tereticornis no Uruguay e gerar informações que contribuam para a identificação das melhores procedências em climas subtropicais úmidos, avaliou-se a sobrevivência, o volume individual, a retidão do fuste e a presença de bifurcações aos 9 anos de idade, em quatro locais em centro, norte e nordeste do Uruguay. Como resultado, foram encontradas diferenças significativas entre procedências para todas as características e interação sitio-procedência significativa para sobrevivência, volume individual e presença de bifurcações. Nenhuma procedên-cia foi melhor em todos os locais. A procedencia de Buckenbowra foi simultaneamente de alto volume e sobre-vivencia. A ausência de uma regionalização clara, juntamente com uma interação significativa procedência por sitio, sugere que a avaliação local das diferentes procedências é essencial para identificar fontes de sementes apropriadas para o cultivo desta espécie e para uso em plantações comerciais

Availability and environmental performance of wood for a second-generation biorefinery.

Abstract:The current global climate change, the 2030 Agenda, and the planetary boundaries have driven new development strategies, such as the circular economy, bioeconomy, and biorefineries. In this framework, this study analyzes the potential availability and sustainability of the wood supply chain for a small-scale biorefinery aiming at producing 280?300 L of bioethanol per ton of dry biomass, consuming 30,000 t of dry biomass per year harvested in a 50 km radius. This wood production goal was assessed from Eucalyptus grandis stands planted for solid wood in northeastern Uruguay. Moreover, to understand the environmental performance of this biomass supply chain, the energy return on investment (EROI), carbon footprint (CF), and potential soil erosion were also assessed. The results showed that the potential wood production would supply an average of 81,800 t of dry mass per year, maintaining the soil erosion below the upper threshold recommended, an EROI of 2.3, and annual CF of 1.22 kg CO2?eq m?3 (2.6 g CO2?eq MJ?1). Combined with the environmental performance of the bioethanol biorefinery facility, these results would show acceptable values of sustainability according to EU Directive 2009/28/ec because the bioethanol CF becomes 1.7% of this petrol?s C

Biomasa total y madera potencialmente disponible para producción de biocombustibles y productos de biorrefinería en el norte de Uruguay.

El presente artículo pone el foco en la estimación de biomasa realizada durante el proyecto BABET REAL5, del que INIA participó. Esta iniciativa apuntó agenerar conocimiento para el aprovechamiento de la cadena de madera sólida (aserrío y tableros), orientado a la producción de biocombustibles y/o productosde biorrefinería, con el fin de impulsar el agregado de valor a nivel local

Efecto de la intensidad de poda en E. grandis al séptimo año de crecimiento: revista forestal.

El objetivo de este ensayo es comparar el efecto de distintos calendarios de poda (frecuencia e intensidad) en el crecimiento de plantaciones de E.grandis en suelos de la zona 7. Para que los mismos sean comparables se definió una altura de poda final constante, por lo que la variable de ajuste es el número de intervenciones