264 research outputs found

    Estimation of muscular forces from SSA smoothed sEMG signals calibrated by inverse dynamics-based physiological static optimization

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    The estimation of muscular forces is useful in several areas such as biomedical or rehabilitation engineering. As muscular forces cannot be measured in vivo non-invasively they must be estimated by using indirect measurements such as surface electromyography (sEMG) signals or by means of inverse dynamic (ID) analyses. This paper proposes an approach to estimate muscular forces based on both of them. The main idea is to tune a gain matrix so as to compute muscular forces from sEMG signals. To do so, a curve fitting process based on least-squares is carried out. The input is the sEMG signal filtered using singular spectrum analysis technique. The output corresponds to the muscular force estimated by the ID analysis of the recorded task, a dumbbell weightlifting. Once the model parameters are tuned, it is possible to obtain an estimation of muscular forces based on sEMG signal. This procedure might be used to predict muscular forces in vivo outside the space limitations of the gait analysis laboratory.Postprint (published version

    Exploring the genesis of glaucony and verdine facies for paleoenvironmental interpretation: a review

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    Green marine clays, known as glaucony and verdine facies, are unique iron-rich minerals typically found in shallow marine sedimentary environments covering large areas of continental shelves today. While on some occasions they have been used effectively as paleoenvironmental indicators associated with transgressive and highstand system tracts, their occurrence can vary in different sedimentary environments. This paper aims to provide a review of the nomenclature and mineralogical composition of these facies, their habits and morphologies, as well as the physico-chemical characteristics of their genesis. This includes water depth, temperature, and geochemical factors that influence the local environments and characteristics of their formation. The article also presents examples from the NW Galician Continental Shelf and discusses the variety of mechanisms behind their genesis and evolution, as well as the challenges surrounding their chronology. Comparisons are drawn with the old facies (ironstone), which can occur in a wider range of marine environments and are sometimes found alongside glaucony and verdine facies in ancient deposits. This highlights the importance of accurately reconstructing the environment of each deposit. The literature reveals many exceptions in relation to the zonal and bathymetric distribution, sedimentation rates, age, etc. of these facies, emphasizing the need for further investigation into their genesis in current and ancient environments. Such research would provide valuable insights for paleogeographic, paleoenvironmental, and stratigraphic interpretations.Universidade de Vigo/CISU

    Design of a patient-tailored active knee-ankle-foot orthosis to assist the gait of spinal cord injured subjects

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    —This paper presents the main design steps in the development of an active knee-ankle-foot orthosis (KAFO) conceived to assist the gait of incomplete spinal cord injured (SCI) subjects. The design approach is based on the idea of modifying the available passive orthoses by adding adaptable mechatronic modules at the joints. This approach has resulted in a prototype that has been tested on SCI patients. The design and control problems found and their adopted solutions are thoroughly described.Postprint (published version

    Design, control and evaluation of a low-cost active orthosis for the gait of spinal cord injured subjects

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    Robotic gait training after spinal cord injury is of high priority to maximize independence and improve the living conditions of the patients. Current rehabilitation robots are expensive and heavy, and are generally found only in the clinical environment. To overcome these issues, we present the design of a low-cost, low-weight and personalized robotic orthosis for incomplete spinal cord injured subjects. The paper also presents a preliminary experimental evaluation of the assistive device on one subject with spinal cord injury that can control hip flexion to a certain extent, but lacks control of knee and ankle muscles. Results show that gait velocity, stride length and cadence of walking increased (24,11%, 7,41% and 15,56%, respectively) when wearing active orthoses compared to the case when the subject used the usual passive orthoses.Postprint (published version

    Adaptation strategies to climate change in the tourist sector: The case of coastal tourism in Spain

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    Tourism activities, that are very important in the Spanish Mediterranean coast since 60s, have been described as highly vulnerable to climate change. Diversification of the tourism and tourist products are often presented as a possible strategy for adapting to the effects of climate change. The present study explores the initiatives in product diversification that are being put into practice in the Spanish Mediterranean coastal tourism sector. To this end, the study focuses on the analysis of the experiences of the rural tourism sector as an alternative to sun-and-sand tourism in the Alt Empordà (Costa Brava, North-eastern Spain). Methodology of this research is based in two aspects: a) desk research of relevant public documents aimed to promote the diversification of the tourist sector; b) regional survey of rural tourism establishments. The analysis reveals a process of diversification that is characterised by spontaneous developments that lack planning and shows an absence of product structuring in accordance with a segmentation of the market. Given these characteristics, the process of diversification that has taken place will not contribute to increasing adaptation\u27s capacity of tourism to climate change or, consequently, to reducing its level of vulnerability
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