Development of a hybrid robotic system based on an adaptive and associative assistance for rehabilitation of reaching movement after stroke

Stroke causes irreversible neurological damage. Depending on the location and the size of this brain injury, different body functions could result affected. One of the most common consequences is motor impairments. The level of motor impairment affectation varies between post-stroke subjects, but often, it hampers the execution of most activities of daily living. Consequently, the quality of life of the stroke population is severely decreased. The rehabilitation of the upper-limb motor functions has gained special attention in the scientific community due the poor reported prognosis of post-stroke patients for recovering normal upper-extremity function after standard rehabilitation therapy. Driven by the advance of technology and the design of new rehabilitation methods, the use of robot devices, functional electrical stimulation and brain-computer interfaces as a neuromodulation system is proposed as a novel and promising rehabilitation tools. Although the uses of these technologies present potential benefits with respect to standard rehabilitation methods, there still are some milestones to be addressed for the consolidation of these methods and techniques in clinical settings. Mentioned evidences reflect the motivation for this dissertation. This thesis presents the development and validation of a hybrid robotic system based on an adaptive and associative assistance for rehabilitation of reaching movements in post-stroke subjects. The hybrid concept refers the combined use of robotic devices with functional electrical stimulation. Adaptive feature states a tailored assistance according to the users’ motor residual capabilities, while the associative term denotes a precise pairing between the users’ motor intent and the peripheral hybrid assistance. The development of the hybrid platform comprised the following tasks: 1. The identification of the current challenges for hybrid robotic system, considering twofold perspectives: technological and clinical. The hybrid systems submitted in literature were critically reviewed for such purpose. These identified features will lead the subsequent development and method framed in this work. 2. The development and validation of a hybrid robotic system, combining a mechanical exoskeleton with functional electrical stimulation to assist the execution of functional reaching movements. Several subsystems are integrated within the hybrid platform, which interact each other to cooperatively complement the rehabilitation task. Complementary, the implementation of a controller based on functional electrical stimulation to dynamically adjust the level of assistance is addressed. The controller is conceived to tackle one of the main limitations when using electrical stimulation, i.e. the highly nonlinear and time-varying muscle response. An experimental procedure was conducted with healthy and post-stroke patients to corroborate the technical feasibility and the usability evaluation of the system. 3. The implementation of an associative strategy within the hybrid platform. Three different strategies based on electroencephalography and electromyography signals were analytically compared. The main idea is to provide a precise temporal association between the hybrid assistance delivered at the periphery (arm muscles) and the users’ own intention to move and to configure a feasible clinical setup to be use in real rehabilitation scenarios. 4. Carry out a comprehensive pilot clinical intervention considering a small cohort of patient with post-stroke patients to evaluate the different proposed concepts and assess the feasibility of using the hybrid system in rehabilitation settings. In summary, the works here presented prove the feasibility of using the hybrid robotic system as a rehabilitative tool with post-stroke subjects. Moreover, it is demonstrated the adaptive controller is able to adjust the level of assistance to achieve successful tracking movement with the affected arm. Remarkably, the accurate association in time between motor cortex activation, represented through the motor-related cortical potential measured with electroencephalography, and the supplied hybrid assistance during the execution of functional (multidegree of freedom) reaching movement facilitate distributed cortical plasticity. These results encourage the validation of the overall hybrid concept in a large clinical trial including an increased number of patients with a control group, in order to achieve more robust clinical results and confirm the presented herein.Programa Oficial de Doctorado en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Ramón Ceres Ruiz.- Secretario: Luis Enrique Moreno Lorente.- Vocal: Antonio Olivier

Daños causados por chinche barriga verde Dichelops melacanthus en maíz transgénico Bacillus thuringiensis (Bt)

Transgenic maize expressing Bacillus thuringiensis (Bt) toxin produces a crystal (Cry) protein toxic to caterpillars that is non-toxic to stink bugs. The objectives of this study were to identify the number of plants attacked and not by Dichelops melacanthus, to evaluate foliar damage through the number of punctures, to evaluate plant height and weight of grain production by corn plants attacked and not. The research was carried out on a commercial production agricultural farm in an area 700 m2. Data were recorded, tabulated in Excel spreadsheet and statistically analyzed by T Student test with 5 % of significance for comparison of two independent groups. The results indicate that 80.7 % of corn plants were attacked by D. melacanthus presenting punctures in their leaves. The average height of attacked plants was 41.2 ± 2.2 cm and 41.5 ± 3.3 cm for not attacking. A significant reduction in the production of 23 % was verified. The weight of grains of the attacked plant was on average 3.048 ± 319 g and 3.956 ± 269 g in a not-attacked plant, demonstrating that the damage caused by D. melhacantus reduces Bt corn productivity.El maíz transgénico que expresa la toxina de Bacillus thuringiensis (Bt) produce un cristal (Cry) de proteína tóxica para las orugas de las hojas y los tallos de maíz Bt, pero es atóxica para chinches. Los objetivos de este estudio fueron identificar la cantidad de plantas de maíz atacadas y no por la chinche barriga verde Dichelops melacanthus, evaluar los daños foliares a través del número de punturas, la altura de plantas y la producción en peso de granos de las plantas de maíz atacadas y no. La investigación se realizó en una granja agrícola de producción comercial en una superficie de 700 m2. Los datos fueron registrados en hoja impresa, tabulada en planilla electrónica Excel y analizados estadísticamente por el test T-Student con una significancia del 5 % para comparación de dos grupos de muestras independientes. Los resultados obtenidos indican que el 80,7 % de las plantas de maíz fueron atacadas por la chinche D. melacanthus presentando punturas foliares. La altura promedio de las plantas atacadas fue de 41,2 ± 2,2 cm y 41,5 ± 3,3 cm de las no atacadas. En relación a la producción se ha verificado una reducción significativa del 23 %. El peso de los granos de maíz por planta atacada tuvo un promedio de 3,048 ± 199 g y 3,956 ± 269 g en planta no atacada, demostrando así que los daños ocasionados por D. melacanthus reducen el rendimiento del maíz Bt

Uso de glicerina bruta en la reducción de pérdidas fermentativas de ensilaje de Pennisetum purpureum

To identify symbiosis between roots and arbuscular mycorrhizal fungi (HMA), methodologies have been reported with variations in concentrations of reagents, temperature, and time of exposure for staining, which does not always adjust to the need for specific cultures due to variation in root structures. The objective of this research was to standardize a methodology to identify mycorrhizal colonization in banana crops in an efficient way. The research was carried out during the second semester of 2022 in the municipality of Apartadó-Antioquia. Four treatments were established that consisted of the evaluation with and without mycorrhizal inoculation with two bleaching techniques each (with and without subjection to Bain Marie). A total of 108 plates (54/technique) were evaluated, where percentage of colonization, visibility, vesicles and arbuscules were identified. There was a complete randomized design. Data were analyzed with R Studio 2022.02 software. An ANAVA and means separations were obtained with a post-hoc analysis of Tukey and Kruskal-Wallis with a confidence level of 95%. Symbiosis was found in all cases, statistical differences were identified in percentage of colonization with 46.8% to 90.2%; arbuscules from 12.1 to 338.0 units and a visibility percentage of 100% in treatments subjected to a Bain Marie, highlighting the need for subjecting banana roots to heat to favor discoloration, staining and visibility due to their architecture.El objetivo de esta investigación fue verificar mejoras en el proceso fermentativo del ensilaje de Pennisetum purpureum cosechados en tres edades de corte con la inclusión de diferentes dosis de glicerina bruta (GB). El experimento fue realizado en un delineamiento completamente al azar en esquema factorial 4x3x3, cuatro dosis de glicerina bruta (0, 10, 20 y 30% de la materia seca [MS] ensilada) y tres edades de corte (30, 45 y 60 días) con tres repeticiones por tratamiento (minisilos). Fueron determinados, pH, producción de efluente (PE), pérdidas por gases (PG) y pérdidas de materia seca (PMS). Los resultados fueron sometidos a un análisis de varianza al 5% de probabilidad. Se ha verificado mejoras en el proceso fermentativo del ensilaje de P. purpureum con la adición de glicerina bruta y reducción de pérdidas. PE se redujo 12,05% para las dosis de 30% de glicerina bruta en el primer corte, para el segundo corte, se redujo del 17,63% en relación al T1 (Testigo) 0% de GB. Las reducciones en las PG en el primer y segundo corte fueron de 22,30% y 82,16% respectivamente, así también la mayor dosis (30% GB) fue la que arrojo mejores resultados con una reducción del 57,3 por ciento. En cuanto a PMS, el ensilaje producido con la mayor dosis de GB (30%) fue el que produjo mejor resultado comparando con las demás dosis. GB puede ser utilizada en el ensilaje de Pennisetum purpureum para promover mejoras en el proceso fermentativo y reducción de las perdidas cualitativas

Productive and Economic Losses Caused by <em>Dichelops melacanthus</em> in Transgenic Bt Maize <em>Bacillus thuringiensis</em>

Transgenic maize expressing Bacillus thuringiensis (Bt) toxin produces a crystal (Cry) protein toxic to caterpillars that is non-toxic to stink bugs. The objectives of this study were to identify the number of plants attacked and not by Dichelops melacanthus, to evaluate foliar damage through the number of punctures, to evaluate plant height, weight of grain production by corn plants attacked and not and economic loss. The research was carried out on a commercial production agricultural farm in an area of 700 m2. Eight areas were evaluated (10 m × 1.8 m) randomly distributed and in V6 physiological stage. Data were recorded, tabulated in Excel spreadsheet and statistically analysed by T Student test with 5% of significance for comparison of two independent groups. The results indicate that 80.7% of corn plants were attacked by D. melacanthus presenting punctures in their leaves. The average height for attacked plants was 41.2 ± 2.2 cm and 41.5 ± 3.3 cm for not attacked. A significant reduction in production of 23% was verified. The weight of grains of attacked plant was in average 3048 ± 319 g and 3956 ± 269 g in not-attacked plant, demonstrating that the damage caused by D. melhacantus reduces Bt corn productivity and loss of income of 98.93 US dollars per hectare