ABSTRACT
Brain-computer interface (BCI) remains an emerging tool that seeks to improve the patient interaction with the therapeutic mechanisms and to generate neuroplasticity progressively through neuromotor abilities. Motor imagery (MI) analysis is the most used paradigm based on the motor cortex's electrical activity to detect movement intention. It has been shown that motor imagery mental practice with movement-associated stimuli may offer an effective strategy to facilitate motor recovery in brain injury patients. In this sense, this study aims to present the BCI associated with visual and haptic stimuli to facilitate MI generation and control the T-FLEX ankle exoskeleton. To achieve this, five post-stroke patients (55-63 years) were subjected to three different strategies using T-FLEX: stationary therapy (ST) without motor imagination, motor imagination with visual stimulation (MIV), and motor imagination with visual-haptic inducement (MIVH). The quantitative characterization of both BCI stimuli strategies was made through the motor imagery accuracy rate, the electroencephalographic (EEG) analysis during the MI active periods, the statistical analysis, and a subjective patient's perception. The preliminary results demonstrated the viability of the BCI-controlled ankle exoskeleton system with the beta rebound, in terms of patient's performance during MI active periods and satisfaction outcomes. Accuracy differences employing haptic stimulus were detected with an average of 68% compared with the 50.7% over only visual stimulus. However, the power spectral density (PSD) did not present changes in prominent activation of the MI band but presented significant variations in terms of laterality. In this way, visual and haptic stimuli improved the subject's MI accuracy but did not generate differential brain activity over the affected hemisphere. Hence, long-term sessions with a more extensive sample and a more robust algorithm should be carried out to evaluate the impact of the proposed system on neuronal and motor evolution after stroke.
Subject(s)
Brain-Computer Interfaces , Exoskeleton Device , Stroke , Ankle , Humans , SurvivorsABSTRACT
Introducción. El perifiton se entiende como una comunidad compleja de microorganismos entre los cuales se encuentran principalmente organismos fotosintéticos y zooplancton adheridos a sustratos, su estudio permite conocer el funcionamiento de los ecosistemas acuáticos, así como el estado y ecología de las comunidades presentes. Objetivo. Evaluar la calidad de agua a partir de la diversidad de perifiton del caño Barandas en la Reserva Natural El Diamante de Las Aguas, en el departamento de Guaviare. Metodología. se midieron las variables fisicoquímicas pH, oxígeno disuelto y temperatura en 5 estaciones a lo largo de 200 metros del cuerpo de agua, se tomaron muestras de perifiton sobrepuesto en superficies de roca, tronco y hojarasca, por medio de un raspado en el interior de un marco de 2x2 cm con 3 repeticiones; para la identificación de los organismos se observaron 25 alícuotas durante 5 minutos por alicuota; para evaluar la calidad de agua, se realizaron índices de diversidad de Shannon-Wiener, Simpson, Menhinick, análisis de correspondencia canónica y el índice biológico de contaminación (IBC). Resultados. Se obtuvieron 465 registros, distribuidos en 82 géneros, los más representativos fueron Campylodiscus (5.81%), Tribonema (8.60%), Ophyoctium (10.75%) y Microspora (11.40%). El BCI arrojó como resultado 11,7 lo cual indica que es una zona de agua limpia. Conclusión. Las variables evaluadas presentaron una relación directa con las comunidades de perifiton encontradas en las estaciones. Los índices de diversidad mostraron que en este caño hay una alta diversidad en las comunidades de perifiton, lo cual indica una buena calidad de agua.
Introduction. The periphyton is understood as a complex community of microorganisms among which are mainly photosynthetic organisms and zooplankton adhered to substrates, its study allows to know the functioning of aquatic ecosystems, as well as the state and ecology of the communities present. Objetive. To evaluate the water quality from the diversity of periphyton of Caño Barandas in the El Diamante de Las Aguas, Natural Reserve in the department of Guaviare. Methodology. The physicochemical variables pH, dissolved oxygen and temperature were measured in 5 stations along 200 meters in the water-body, followed by samples of the periphyton superimposed on rock surfaces, trunk and litter, by means of a scraping inside a 2x2 cm frame, with 3 repetitions, subsequently, for the identification of the organisms, 25 aliquots were observed for 5 minutes per aliquot. to evaluate the water quality. Shannon-Wiener, Simpson, Menhinick diversity indices, canonical correspondence analysis and the biological contamination index, Results. A total of 465 records were obtained, distributed in 82 genera, the most representative were Campylodiscus (5.81%), Tribonema (8.60%), Ophyoctium (10.75%) and Microspora (11.40%). The latter gave 11.7 as a result, which indicates that it is a clean water area. Conclusion. The evaluated variables presented a direct relationship with the periphyton communities found in the stations. The diversity indices showed that in this area there is a high diversity in the periphyton communities, which indicates a good water quality.