523 research outputs found

    Development of a general purpose tour-guide robot able to learn routes from people and to adapt and move in unstructured and crowded environments

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    Industrial robots has consolidated its presence in factories and professional environments during the last few years. However, in the next decades it is expected that service robots approach an exponential growth, reaching the mass market and taking over our homes and offices. In order to meet these predictions, there is still some way to go. Service robots need to be able to adapt to the dynamic nature of unstructured environments, where people walk by, and furniture might be moved around. In recent years, tour-guide robots have become a popular research topic because they face many of the challenges which have arisen in service robotics. Essentially, a tour-guide robot must be able to interact with humans, who might demand routes from the robot. Also, in order to showcase these routes, the robot must have a reliable and flexible perception of the changing environment where it operates. For these reasons, the goal of this thesis is to build a general purpose tourguide robot, which should be able to learn routes while following an instructor. The instructor can be anyone, i.e members of the staff from where the robot operates. This makes necessary the development of robust and flexible behaviours. More specifically, we have a) designed and developed a person-following behaviour, b) a human-robot interaction scheme, c) the processes for route recording and reproduction, and d) a strategy to allow the robot to learn its own control algorithms..

    Combined sterilization and fabrication of drug-loaded scaffolds using supercritical CO2 technology

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    The access of biodegradable scaffolds to the clinical arena is constrained by the absence of a suitable sterilization technique for the processing of advanced polymeric materials. Sterilization with supercritical CO2 (scCO2) may circumvent some technological limitations (e.g., low temperature, no chemical residues on the material), although scCO2 can plasticize the polymer depending on the processing conditions used. In this latter case, the integration of the manufacturing and sterilization processes is of particular interest to obtain sterile and customized scaffolds in a single step. In this work, scCO2 was exploited as a concomitantly foaming and sterilizing agent for the first time, developing a one-step process for the production of vancomycin-loaded poly(ε-caprolactone) (PCL) bone scaffolds. The effect of the CO2 contact time on the sterility levels of the procedure was investigated, and the sterilization efficiency was evaluated against dry spores (Bacillus stearothermophilus, Bacillus pumilus and Bacillus atrophaeus). Vancomycin-loaded PCL scaffolds had relevant sustained release profiles for the prophylaxis of infections at the grafted area, even those caused by methicillin-resistant Staphylococcus aureus (MRSA). The biological performance of the scaffolds was evaluated in vitro regarding human mesenchymal stem cells (hMSCs) attachment and growth. Finally, the biocompatibility and angiogenic response of the manufactured sterile scaffolds was assessed in ovo through chick chorioallantoic membrane (CAM) assaysThis research was funded by Xunta de Galicia [ED431C 2020/17], MICINN [PID2020-120010RB-I00], Consellería de Sanidade, Servizo Galego de Saúde, Axencia de Coñecemento en Saúde (ACIS, CT850A-G), Agencia Estatal de Investigación [AEI] and FEDER funds. V. Santos-Rosales acknowledges to Xunta de Galicia (Consellería de Cultura, Educación e Ordenación Universitaria) for a predoctoral research fellowship [ED481A-2018/014]S

    Self-Organized Multi-Camera Network for a Fast and Easy Deployment of Ubiquitous Robots in Unknown Environments

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    To bring cutting edge robotics from research centres to social environments, the robotics community must start providing affordable solutions: the costs must be reduced and the quality and usefulness of the robot services must be enhanced. Unfortunately, nowadays the deployment of robots and the adaptation of their services to new environments are tasks that usually require several days of expert work. With this in view, we present a multi-agent system made up of intelligent cameras and autonomous robots, which is easy and fast to deploy in different environments. The cameras will enhance the robot perceptions and allow them to react to situations that require their services. Additionally, the cameras will support the movement of the robots. This will enable our robots to navigate even when there are not maps available. The deployment of our system does not require expertise and can be done in a short period of time, since neither software nor hardware tuning is needed. Every system task is automatic, distributed and based on self-organization processes. Our system is scalable, robust, and flexible to the environment. We carried out several real world experiments, which show the good performance of our proposalThis work was supported by the research projects TIN2009-07737, INCITE08PXIB262202PR, and TIN2012-32262, the grant BES-2010-040813 FPI-MICINN, and by the grant “Consolidation of Competitive Research Groups, Xunta de Galicia ref. 2010/6”S

    A clustering-based method for single-channel fetal heart rate monitoring

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    Non-invasive fetal electrocardiography (ECG) is based on the acquisition of signals from abdominal surface electrodes. The composite abdominal signal consists of the maternal electrocardiogram along with the fetal electrocardiogram and other electrical interferences. These recordings allow for the acquisition of valuable and reliable information that helps ensure fetal well-being during pregnancy. This paper introduces a procedure for fetal heart rate extraction from a single-channel abdominal ECG signal. The procedure is composed of three main stages: a method based on wavelet for signal denoising, a new clustering-based methodology for detecting fetal QRS complexes, and a final stage to correct false positives and false negatives. The novelty of the procedure thus relies on using clustering techniques to classify singularities from the abdominal ECG into three types: maternal QRS complexes, fetal QRS complexes, and noise. The amplitude and time distance of all the local maxima followed by a local minimum were selected as features for the clustering classification. A wide set of real abdominal ECG recordings from two different databases, providing a large range of different characteristics, was used to illustrate the efficiency of the proposed method. The accuracy achieved shows that the proposed technique exhibits a competitve performance when compared to other recent works in the literature and a better performance over threshold-based techniques.This work has been partially funded by Banco Santander and Centro Mixto UGR-MADOC through project SIMMA (code 2/16). The contribution of Antonio García has been partially funded by Spain's Ministerio de Educación, Cultura y Deporte (Programa Estatal de Promoción del Talento y su Empleabilidad en I+D+i, Subprograma Estatal de Movilidad, within Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016) under a "Salvador de Madariaga" grant (PRX17/00287)

    Sterile and dual-porous aerogels scaffolds obtained through a multistep supercritical CO2-based approach

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    Aerogels from natural polymers are endowed with attractive textural and biological properties for biomedical applications due to their high open mesoporosity, low density, and reduced toxicity. Nevertheless, the lack of macroporosity in the aerogel structure and of a sterilization method suitable for these materials restrict their use for regenerative medicine purposes and prompt the research on getting ready-to-implant dual (macro + meso)porous aerogels. In this work, zein, a family of proteins present in materials for tissue engineering, was evaluated as a sacrificial porogen to obtain macroporous starch aerogels. This approach was particularly advantageous since it could be integrated in the conventional aerogel processing method without extra leaching steps. Physicochemical, morphological, and mechanical characterization were performed to study the effect of porogen zein at various proportions (0:1, 1:2, and 1:1 zein:starch weight ratio) on the properties of the obtained starch-based aerogels. From a forward-looking perspective for its clinical application, a supercritical CO2 sterilization treatment was implemented for these aerogels. The sterilization efficacy and the influence of the treatment on the aerogel final properties were evaluated mainly in terms of absence of microbial growth, cytocompatibility, as well as physicochemical, structural, and mechanical modifications.Work supported by Xunta de Galicia [ED431F 2016/010 & ED431C 2016/008], MINECO [SAF2017-83118R], AEI, FEDER and Interreg VAPOCTEP Programme [0245_IBEROS_1_E].C.A.García-González acknowledges to MINECO for a Ramón y Cajal Fellowship [RYC2014-15239]. V. Santos-Rosales acknowledges to Xunta de Galicia (Consellería de Cultura, Educación e Ordenación Universitaria) for a predoctoral research fellowship [ED481A-2018/014]. A.L. Oliveira acknowledges Portuguese National Funds from FCT—Fundação para a Ciência e a Tecnologia through Program FCT Investigator (IF/00411/2013), project SERICAMED (IF/00411/2013/CP1167) and project UID/Multi/50016/2013. Work carried out in the frame of the COST-Action “Advanced Engineering and Research of aeroGels for Environment and Life Sciences” (AERoGELS, ref. CA18125) funded by the European CommissionS

    Tendencias y variabilidad climática para el siglo XXI en Galicia [Póster]

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    Póster presentado en: VIII Congreso de la Asociación Española de Climatología celebrado en Salamanca entre el 25 y el 28 de septiembre de 2012.Este trabajo ha sido financiado por la Xunta de Galicia bajo el proyecto de investigación No. 10PXIB383169PR y cofinanciado por los fondos para el desarrollo europeo regional (FEDER)

    Tendencias y variabilidad climática para el siglo XXI en Galicia

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    Ponencia presentada en: VIII Congreso de la Asociación Española de Climatología celebrado en Salamanca entre el 25 y el 28 de septiembre de 2012.[ES]En las últimas décadas se ha llegado a la conclusión de que el clima está cambiando por causas antropogénicas. A nivel general este cambio se sustancia en un aumento de temperatura y del nivel de mar. En cuanto a las lluvias existe una mayor incertidumbre, pero todo parece indicar que el ciclo hidrológico debería aumentar en intensidad, incrementando la probabilidad de sequía en aquellas zonas actualmente sujetas a la misma. Sin embargo a nivel más local estos cambios no han sido tan estudiados, ya que los modelos climáticos no llegaban al nivel de resolución necesario. En los últimos años sí se alcanza ese nivel de resolución. Por tanto en este trabajo se han usado los resultados de modelos de cambio climático a nivel regional ejecutados dentro del proyecto ENSEMBLES. El área de estudio es el noroeste de la península Ibérica. Los resultados sugieren que las temperaturas también aumentarán en el área de estudio, mientras que las lluvias no muestran un patrón demasiado definido.[EN]In recent decades it has been concluded that the climate is changing due to anthropogenic causes. In general this change provokes an increase in temperature and sea level. Considering the rain there is more uncertainty, but it appears that the hydrological cycle is expected to increase in intensity, increasing the likelihood of drought in areas currently subject to it. Nevertheless, at a more local level these changes have not been so intensively studied, because climate models do not reach the level of resolution required. In recent years this level of resolution has been acheived. Therefore in this work we have used the results of models of regional climate change implemented within the ENSEMBLES project. The study area is the northwest of the Iberian Peninsula. The results show that temperatures will also increase in the study area, while the rains did not show a defined pattern.Este trabajo ha sido financiado por la “Xunta de Galicia” bajo el proyecto 10PXIB383169PR

    Supercritical CO2 technology for one-pot foaming and sterilization of polymeric scaffolds for bone regeneration

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    Sterilization is a quite challenging step in the development of novel polymeric scaffolds for regenerative medicine since conventional sterilization techniques may significantly alter their morphological and physicochemical properties. Supercritical (sc) sterilization, i.e. the use of scCO2 as a sterilizing agent, emerges as a promising sterilization method due to the mild operational conditions and excellent penetration capability. In this work, a scCO2 protocol was implemented for the one-pot preparation and sterilization of poly(-caprolactone) (PCL)/poly(lactic-co-glycolic acid) (PLGA) scaffolds. The sterilization conditions were established after screening against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) vegetative bacteria and spores of Bacillus stearothermophilus, Bacillus pumilus and Bacillus atrophaeus. The transition from the sterilization conditions (140 bar, 39 °C) to the compressed foaming (60 bar, 26 °C) was performed through controlled depressurization (3.2 bar/min) and CO2 liquid flow. Controlled depressurization/pressurization cycles were subsequently applied. Using this scCO2 technology toolbox, sterile scaffolds of well-controlled pore architecture were obtained. This sterilization procedure successfully achieved not only SAL-6 against well-known resistant bacteria endospores but also improved the scaffold morphologies compared to standard gamma radiation sterilization proceduresThis work was supported by Xunta de Galicia [ED431F 2016/01, ED431C 2020/17], MCIUN [RTI2018-094131-A-I00], MINECO [SAF2017-83118-R], Consellería de Sanidade, Servizo Galego de Saúde, Axencia de Coñecemento e Saúde (ACIS, CT850A-G), Agencia Estatal de Investigación [AEI] and FEDER funds. V. Santos-Rosales acknowledges to Xunta de Galicia (Consellería de Cultura, Educación e Ordenación Universitaria) for a predoctoral research fellowship [ED481A-2018/014]. C.A. García-González acknowledges to MINECO for a Ramón y Cajal Fellowship [RYC2014-15239]S

    Nanocolumnar growth of thin films deposited at oblique angles: Beyond the tangent rule

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    The growth of nanostructured physical vapor deposited thin films at oblique angles is becoming a hot topic for the development of a large variety of applications. Up to now, empirical relations, such as the so-called tangent rule, have been uncritically applied to account for the development of the nanostructure of these thin films even when they do not accurately reproduce most experimental results. In the present paper, the growth of thin films at oblique angles is analyzed under the premises of a recently proposed surface trapping mechanism. The authors demonstrate that this process mediates the effective shadowing area and determines the relation between the incident angle of the deposition flux and the tilt angle of the columnar thin film nanostructures. The analysis of experimental data for a large variety of materials obtained in our laboratory and taken from the literature supports the existence of a connection between the surface trapping efficiency and the metallic character of the deposited materials. The implications of these predictive conclusions for the development of new applications based on oblique angle deposited thin films are discussed.Junta de Andalucía P09-CTS- 5189, TEP5283, FQM-6900Ministerio de Ciencia e Innovación CSD2008-00023, MAT2010-21228, MAT2010-1844

    Attention deficit hyperactivity disorder: Genetic association study in a cohort of spanish children

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    Background: Attention deficit hyperactivity disorder (ADHD) has a strong genetic component. The study is aimed to test the association of 34 polymorphisms with ADHD symptomatology considering the role of clinical subtypes and sex in a Spanish population. Methods: A cohort of ADHD 290 patients and 340 controls aged 6–18 years were included in a case–control study, stratified by sex and ADHD subtype. Multivariate logistic regression was used to detect the combined effects of multiple variants. Results: After correcting for multiple testing, we found several significant associations between the polymorphisms and ADHD (p value corrected ≤0.05): (1) SLC6A4 and LPHN3 were associated in the total population; (2) SLC6A2, SLC6A3, SLC6A4 and LPHN3 were associated in the combined subtype; and (3) LPHN3 was associated in the male sample. Multivariable logistic regression was used to estimate the influence of these variables for the total sample, combined and inattentive subtype, female and male sample, revealing that these factors contributed to 8.5, 14.6, 2.6, 16.5 and 8.5 % of the variance respectively. Conclusions: We report evidence of the genetic contribution of common variants to the ADHD phenotype in four genes, with the LPHN3 gene playing a particularly important role. Future studies should investigate the contribution of genetic variants to the risk of ADHD considering their role in specific sex or subtype, as doing so may produce more predictable and robust modelsThis study was supported by the following research grants: Fundacion Alicia Koplowitz (4019-004), Biobank of Fundacion Jimenez Diaz Hospital (RD09/0076/00101, Instituto de Salud Carlos III) and the Centre for Biomedical Network Research on Rare Diseases -CIBERER (06/07/0036). The work of CG-S is supported by a Fundacion Conchita Rabago Gran
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