Examinando por Autor "Martinez, F."
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Ítem A Novel Low-Cost Sensor Prototype for Nocturia Monitoring in Older People(Institute of Electrical and Electronics Engineers Inc., 2018-09) Taramasco, C.; Rodenas, T.; Martinez, F.; Fuentes, P.; Munoz, R.; Olivares, R.; Albuquerque, V.H.C.; Demongeot, J.Nocturia is frequently defined as the necessity to get out of bed at least one time during the night to urinate, with each of these episodes being preceded and continued by sleep. Several studies suggest that an increase of nocturia is seen with the onset of age, occurring in around 70% of adults over the age of 70. Its appearance is associated with detrimental quality of life for those who present nocturia, since it leads to daytime sleepiness, cognitive dysfunction, among others. Currently, a voiding diary is necessary for nocturia assessment; these are prone to bias due to their inherent subjectivity. In this paper, we present the design of a low-cost device that automatically detects micturition events. The device obtained 73% in sensibility and 81% in specificity; these results show that systems such as the proposed one can be a valuable tool for the medical team when evaluating nocturia. © 2013 IEEE.Ítem A novel monitoring system for fall detection in older people(2169-3536, 2018-07) Taramasco, C.; Rodenas, T.; Martinez, F.; Fuentes, P.; Munoz, R.; Olivares, R.; De Albuquerque, V.H.C.; Demongeot, J.Each year, more than 30% of people over 65 years-old suffer some fall. Unfortunately, this can generate physical and psychological damage, especially if they live alone and they are unable to get help. In this field, several studies have been performed aiming to alert potential falls of the older people by using different types of sensors and algorithms. In this paper, we present a novel non-invasive monitoring system for fall detection in older people who live alone. Our proposal is using very-low-resolution thermal sensors for classifying a fall and then alerting to the care staff. Also, we analyze the performance of three recurrent neural networks for fall detections: Long short-term memory (LSTM), gated recurrent unit, and Bi-LSTM. As many learning algorithms, we have performed a training phase using different test subjects. After several tests, we can observe that the Bi-LSTM approach overcome the others techniques reaching a 93% of accuracy in fall detection. We believe that the bidirectional way of the Bi-LSTM algorithm gives excellent results because the use of their data is influenced by prior and new information, which compares to LSTM and GRU. Information obtained using this system did not compromise the user's privacy, which constitutes an additional advantage of this alternative. © 2013 IEEE.Ítem Superior vena cava syndrome due to a leiomyosarcoma of the anterior mediastinum: a case report and literature overview(Elsevier Ltd, 2014) Labarca, E.; Zapico, A.; Ríos, B.; Martinez, F.; Santamarina, M.INTRODUCTION: Leiomyosarcomas are an infrequent cause of malignant superior vena cava syndrome (VCS). PRESENTATION OF CASE: A 51-year old male patient was admitted for a three-day history of dyspnoea, dysphagia and erythema of the head and neck. Computed tomography and magnetic resonance imaging showed a lesion arising on the anterior mediastinum, which was in close proximity with a thrombus in the superior vena cava. Surgical excision was performed, including open resection of the primary tumour and an atrio-innominate vein bypass with 8-mm polytetrafluoroethylene (PTFE). Histology confirmed a leiomyosarcoma and postoperative radiotherapy sessions were performed. Due to evidence of enlarge ment of the thrombus, a second intervention was undertaken. In this procedure, a remainder of the primary tumour was resected and the superior vena cava reconstructed with an autologous pericardium patch. The patient recovered satisfactorily and was discharged on the seventh postoperative day, with no evidence for relapse after 10 months of follow-up. DISCUSSION: Leiomyosarcomas comprise less than 2% of the tumours of the mediastinum and are a rare cause of paraneoplastic VCS. Male patients in their sixties are most commonly affected. Relapses seem to be common, and thus a careful follow-up is often recommended. CONCLUSION: In spite of the limited data on the management of thoracic leiomyosarcomas, surgery is currently considered the mainstay of treatment. © 2014 The Authors. Published by Elsevier Ltd. on behalf of Surgical Associates Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).Ítem Synthesis, thermal behavior, and aggregation in aqueous solution of poly(methyl Methacrylate)-b-poly(2-hydroxyethyl Methacrylate(Chilean Chemical Society, 2013-12) Acevedo, B.; Martinez, F.; Olea, A.Amphiphilic block copolymers of poly(methyl methacrylate) PMMA and poly(2-hidroxyethyl methacrylate) PHEMA were synthesized by a two-step atom transfer radical polymerization (ATRP). Copolymers with various degrees of polymerization and different relative block sizes were obtained. The structure of the resulting polymers have been characterized and verified by FT-IR and 1H-NMR, molecular weight were determined by size exclusion chromatography analyses. The thermal properties of these polymers were investigated by differential scanning calorimetry DSC and thermogravimetric analysis TGA. The glass transition temperature of mono halogenated PMMA increases from 116 C to 123 C with increasing molecular weight, whereas the glass transition temperature of block copolymers depends slightly on polymer structure. The derivatives of TGA curves indicate that thermal degradation occurs in one stage. The self-assembly of PMMA-b-PHEMA in aqueous solution have been investigated by fluorescence probing methods. The critical micelle concentrations are in the range 10-6 - 10-7 M. The micropolarity sensed by pyrene is higher than in aggregates formed by block copolymers based on polystyrene.