An Analytical Approach to Avoid Obstacles in Mobile Robot Navigation

A nonlinear supervised globally stable controller is proposed to reactively guide a mobile robot to avoid obstacles while seeking a goal. Whenever the robot detects an object nearby, its orientation is changed to be aligned with the tangent to the border of the obstacle. Then, the robot starts following it, looking for a feasible path to its goal. The supervisor is responsible for deciding which path to take when the robot faces some particular obstacle configurations that are quite difficult to deal with. Several simulations and experiments were run to validate the proposal, some of which are discussed here. To run the experiments, the proposed controller is programmed into the onboard computer of a real unicycle mobile platform, equipped with a laser range scanner. As for the simulations, the models of the same experimental setup were used. The final conclusion is that the nonlinear supervised controller proposed to solve the problem of avoiding obstacles during goal seeking has been validated, based on the theoretical analysis, and the simulated and experimental results.Fil: Brandao, Alexandre Santos. Federal University of Viçosa. Department of Electrical Engineering; BrasilFil: Sarcinelli Filho, Mário . Federal University of Espírito Santo. Department of Electrical Engineering; ArgentinaFil: Carelli Albarracin, Ricardo Oscar. Universidad Nacional de San Juan. Facultad de Ingenieria. Instituto de Automática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Dynamic model of lithium polymer battery: Load resistor method for electric parameters identification

Maximum battery runtime and its transients behaviors are crucial in many applications. With accurate battery models in hand, circuit designers can evaluate the performance of its developments considering the influence of a finite source of energy which has a particular dynamics; as well as the energy storage systems can be optimized. First, this work describes a complete dynamic model of a lithium polymer battery. In the sequel a simple and novel procedure is used to obtain the electric parameters of adopted model with the advantage of using only one resistor to represent the battery load and a pc-connected multimeter. The methodology used to identify the parameters of the battery model is simple, clearly explained and can be applied to various types of batteries. Simulation and experimental results are presented and discussed, demonstrating the good performance of the proposed identification methodology.Fil: Gandolfo, Daniel. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Automática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Brandao, Alexandre. Universidade Federal de Viçosa; BrasilFil: Patiño, Héctor Daniel. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Automática; ArgentinaFil: Molina, Marcelo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentin

Investigation of fMRI protocol for evaluation of Gestural Interaction applied to upper-limb motor improvement

The use of Virtual Reality (VR) systems for rehabilitation treatment as a complement to conventional therapy has grown in recent years. Upper limbs therapy using VR has already been shown useful for stroke patients. In this work, we present a pilot study aiming to investigate the use of a functional magnetic resonance imaging (fMRI) protocol to analyze brain connectivity changes in subjects undergoing upper limb training through a VR environment. Thirteen healthy subjects underwent resting-state fMRI exams before and after a VR session. Although no significant changes are expected in healthy subjects performing only one training session, this study could pave the way for future studies performed with both stroke patients or athletes performing more sessions. Indeed, no significant changes in motor cortex connectivity were found. Nonetheless, an evaluation protocol for this type of VR rehabilitation procedure was successfully established, to be used in further studies with patients or athletes

Graph analysis of cortical reorganization after virtual reality-based rehabilitation following stroke: a pilot randomized study

IntroductionStroke is the leading cause of functional disability worldwide. With the increase of the global population, motor rehabilitation of stroke survivors is of ever-increasing importance. In the last decade, virtual reality (VR) technologies for rehabilitation have been extensively studied, to be used instead of or together with conventional treatments such as physiotherapy or occupational therapy. The aim of this work was to evaluate the GestureCollection VR-based rehabilitation tool in terms of the brain changes and clinical outcomes of the patients.MethodsTwo groups of chronic patients underwent a rehabilitation treatment with (experimental) or without (control) complementation with GestureCollection. Functional magnetic resonance imaging exams and clinical assessments were performed before and after the treatment. A functional connectivity graph-based analysis was used to assess differences between the connections and in the network parameters strength and clustering coefficient.ResultsPatients in both groups showed improvement in clinical scales, but there were more increases in functional connectivity in the experimental group than in the control group.DiscussionThe experimental group presented changes in the connections between the frontoparietal and the somatomotor networks, associative cerebellum and basal ganglia, which are regions associated with reward-based motor learning. On the other hand, the control group also had results in the somatomotor network, in its ipsilateral connections with the thalamus and with the motor cerebellum, which are regions more related to a purely mechanical activity. Thus, the use of the GestureCollection system was successfully shown to promote neuroplasticity in several motor-related areas

Biocompatibility and setting time of CPM-MTA and white Portland cement clinker with or without calcium sulfate

To evaluate the biocompatibility and the setting time of Portland cement clinker with or without 2% or 5% calcium sulfate and MTA-CPM. Twenty-four mice (Rattus norvegicus) received subcutaneously polyethylene tubes filled with Portland cement clinker with or without 2% or 5% calcium sulfate and MTA. After 15, 30 and 60 days of implantation, the animals were killed and specimens were prepared for microscopic analysis. For evaluation of the setting time, each material was analyzed using Gilmore needles weighing 113.5 g and 456.5 g, according to the ASTM specification Number C266-08 guideline. Data were analyzed by ANOVA and Tukey's test for setting time and Kruskal-Wallis and Dunn test for biocompatibility at 5% significance level. Histologic observation showed no statistically significant difference of biocompatibility (p>0.05) among the materials in the subcutaneous tissues. For the setting time, clinker without calcium sulfate showed the shortest initial and final setting times (6.18 s/21.48 s), followed by clinker with 2% calcium sulfate (9.22 s/25.33 s), clinker with 5% calcium sulfate (10.06 s/42.46 s) and MTA (15.01 s/42.46 s). All the tested materials showed biocompatibility and the calcium sulfate absence shortened the initial and final setting times of the white Portland cement clinke

Relação entre antropometria, gordura corporal e autoconceito de adolescentes do sexo feminino

  Obesity poses future metabolic risks, as well as contributing to the development of early psychosocial problems and to the reduction of adolescent quality of life. Self-concept is an important indicator of psychological well-being, especially in the young age, however, several factors can contribute to the perception of self-concept, among them is the nutritional status, which is constantly modified in this phase of life. In this sense, the nutritional status variables may be associated with positive or negative concepts about themselves, favoring the understanding of psychosocial factors of the young population in favor of healthy behaviors. Thus, this study sought to analyze the relationship of waist circumference, fat percentage and the physical and global self-concept of female adolescents. For that, a cross-sectional study was carried out with the participation of 101 female adolescents, students of the High School of a State Technical School of the city of São Paulo. The Harter self - perception scale for adolescents was validated for Brazilian adolescents, in the dimensions of the physical and global self - concept, and anthropometric measures of body mass and height were checked for BMI, skin folds for fat percentage and waist circumference. The data were categorized and correlated with each other. An inverse correlation was found between the variables physical self-concept and waist circumference corroborating with other studies. Keywords: self-concept; physical self-concept; adolescent; anthropometry.    La obesidad trae riesgos metabólicos futuros, además de contribuir en el desarrollo de problemas psicosociales precoces y en la reducción de la calidad de vida del adolescente. El autoconcepto es un importante indicador de bienestar psicológico, principalmente en la edad joven, sin embargo, diversos factores pueden contribuir a la percepción del autoconcepto, entre ellos, está el estado nutricional, que es constantemente modificado en esa fase de la vida. En este sentido, las variables del estado nutricional pueden estar asociadas a conceptos positivos o negativos sobre sí mismo, favoreciendo el entendimiento de factores psicosociales de la población joven en pro de comportamientos saludables. Así, ese trabajo buscó analizar la relación de la circunferencia de cintura, el porcentaje de grasa y el autoconcepto físico y global de adolescentes del sexo femenino. Para ello, se realizó un estudio transversal con la participación de 101 adolescentes del sexo femenino, estudiantes de la Enseñanza Media de una Escuela Técnica Estadual de la ciudad de São Paulo. Se utilizó la escala de Autopercepción de Harter para Adolescentes validada para adolescentes brasileños, en las dimensiones del autoconcepto físico y global, y medidas medidas antropométricas de masa corporal y estatura para la verificación del IMC, pliegues cutáneos para el porcentaje de grasa y circunferencia de cintura. Los datos fueron categorizados y correlacionados entre sí. Se encontró correlación inversa entre las variables autoconcepto físico y circunferencia de cintura corroborando con otros estudios. Palabras clave: autoconcepto; autoconcepto físico; adolescente; antropometría.  A obesidade traz futuras cãibras metabólicas, além de contribuir não para o desenvolvimento de problemas psicossociais e precários na redução da qualidade de vida do adolescente. O e Um autoconceito importante indicador de bem-estar psicológico, Jovem principalmente na Idade, não entanto, vários Fatores PODEM contribuir para uma Percepção fazer autoconceito entre ELES é ou estado nutricional, que E nessa fase constantemente modificado dá vida. Nesse sentido, como fazem Variáveis ​​PODEM estado nutricional ser positivo OU Associated negativo para se MESMO CONCEITOS, favorecendo ou Entendimento de psicossociais Fatores Jovem em Prol da População de comportamentos Saudáveis. Assim, esse trabalho buscou analisar a relação da circunferência da cintura, ou percentual de gordura e autoconceito físico e global de adolescentes do sexo feminino. Por isso, Foi realizado um estudo transversal com a participação de 101 adolescentes do sexo feminino, estudantes do Ensino Médio de uma Escola Técnica Estadual de São Paulo. Foi usado para dimensionar Autopercepção Harter adolescente validado para adolescentes Brasileiros, NAS fazer Dimensões autoconceito físico e, em geral, e aferidas medidas antropométricas de massa corporal e estatura para a verificação do IMC, pele para ou percentual de pregas de gordura e circunferência da cintura. Os foram foram categorizados e correlacionados entre si. Foi encontrada uma correlação inversa entre autoconceito físico variado e circunferência de cintura, corroborando com outros estudos. Foi usado para dimensionar Autopercepção Harter adolescente validado para adolescentes Brasileiros, NAS fazer Dimensões autoconceito físico e, em geral, e aferidas medidas antropométricas de massa corporal e estatura para a verificação do IMC, pele para ou percentual de pregas de gordura e circunferência da cintura. Os foram foram categorizados e correlacionados entre si. Foi encontrada uma correlação inversa entre autoconceito físico variado e circunferência de cintura, corroborando com outros estudos. Foi usado para dimensionar Autopercepção Harter adolescente validado para adolescentes Brasileiros, NAS fazer Dimensões autoconceito físico e, em geral, e aferidas medidas antropométricas de massa corporal e estatura para a verificação do IMC, pele para ou percentual de pregas de gordura e circunferência da cintura. Os foram foram categorizados e correlacionados entre si. Foi encontrada uma correlação inversa entre autoconceito físico variado e circunferência de cintura, corroborando com outros estudos. Os foram foram categorizados e correlacionados entre si. Foi encontrada uma correlação inversa entre autoconceito físico variado e circunferência de cintura, corroborando com outros estudos. Os foram foram categorizados e correlacionados entre si. Foi encontrada uma correlação inversa entre autoconceito físico variado e circunferência de cintura, corroborando com outros estudos. Palavras-chave: autoconceito; autoconceito físico; adolescente antropometria   &nbsp

Behaviour of the foramen ovale flow in fetuses with intrauterine growth restriction

Foramen ovale (FO) flow may be altered in IUGR. .is study was designed to test this hypothesis. Methods. Forty pregnant women (24–38 weeks) were divided into 3 groups: group I (IUGR), group II (adequate growth and maternal hypertension), and group III (normal controls). Impedance across the FO was assessed by the FO pulsatility index (FOPI): (systolic velocity − presystolic velocity)/mean velocity. Statistical analysis utilized ANOVA, Tukey test, and ROC curves. Results. Mean FOPI in IUGR fetuses (n=15) was 3.70 ± 0.99 (3.15–4.26); in the group II (n=12), it was 2.84 ± 0.69 (2.40–3.28), and in the group III (n=13), it was 2.77 ± 0.44 (2.50–3.04) (p=0.004). FOPI and UtA RI were correlated (r= 0.375, p= 0.017), as well as FOPI and UA RI (r= 0.356, p= 0.024) and, inversely, FOPI and MCA RI (r= −0.359, p= 0.023). Conclusions. .e FO flow pulsatility index is increased in fetuses with IUGR, probably as a result of impaired left ventricular diastolic functio