Conception, réalisation et mise en oeuvre d’un calcul de risque de chute en temps réel dans un micro-logiciel embarqué dans une semelle intelligente

Mon projet de recherche consiste à développer, sur une semelle instrumenté, une reconnaissance de la marche et un calcul du risque lié à celle-ci qui soit fiable. Pour développer une reconnaissance fiable, il a fallu s’appuyer sur la littérature déjà existante mais aussi développer des moyens de vérifications des procédés mis en place. Pour cela, il a fallu créer un système embarqué que l’on peut diviser en plusieurs étapes : 1) définition d’une fenêtre d’analyse 2) extraction des signaux des capteurs. 3) détection de la marche 4) traitement des signaux pendant l’activité 5) calcul du risque lié à la marche 6) exportation des résultats obtenus pour en faire la vérification. Pour la première étape, il est important de délimiter une fenêtre pouvant contenir l’activité à détecter, la fenêtre d’analyse étant en corrélation avec le temps, il faut la définir suffisamment grande pour que le début et la fin de l’activité soit dans cette fenêtre mais il est aussi important de ne pas la prendre trop grande car, utilisant de la technologie embarqué, les ressources disponibles ne sont pas « infinies » comme sur un ordinateur. À la seconde étape, l’acquisition des signaux consiste à mesurer les mouvements de l’opérateur à l’aide d’un instrument de mesure non-invasif, non-intrusif capable de fonctionner dans son milieu de travail in-situ. La troisième étape consiste, à l’aide de la littérature, à définir ce qu’est un pas traduisant la marche en utilisant les capteurs présents dans la semelle. Ainsi on peut définir ce qu’est un pas et délimiter un segment de notre fenêtre sur lequel nous ferons l’analyse du risque. Une fois le segment de données extrait à l’aide de la détection de la marche, des caractéristiques sont extraites sur les signaux relevés afin de permettre de diminuer le nombre de données à traiter ainsi que de permettre de créer plus facilement une distinction entre la marche et les autres activités. En cinquième étape, nous calculons le risque à l’aide des caractéristiques extraites, ce modèle de calcul est calqué sur un modèle déjà existant très fiable et pourtant très simpliste basé sur un modèle statistique. Pour la dernière étape, les données obtenues sont transférés vers un ordinateur afin de faire un traitement sur Matlab des résultats obtenus, à la fois sur le calcul des caractéristiques mais aussi sur le calcul du risque. Une fois la comparaison effectuée, le calcul de la déviation de l’écart mesuré avec les valeurs attendues donne des résultats de l’ordre de 10−7% pour les résultats avec l’écart le plus grand. Dans les meilleurs cas, la précision atteinte est de 100%, tout particulièrement pour le calcul du risque qui est le résultat le plus intéressant à étudier. Ces résultats n’impliquent pas que le risque est reconnu dans 100% des situations mais plutôt que les résultats des calculs sont totalement fiables. Ainsi, la semelle mis en place dispose des meilleurs outils pour atteindre les résultats escomptés dans la détection des autres activités

Physico-chemical modifications of the interactions between hemp fibres and a lime mineral matrix: impacts on mechanical properties of mortars

International audienceIn order to understand the physico-chemical mechanisms governing interactions between hemp fibres and a lime-based mineral matrix, the consequences of various chemical treatments onto hemp fibres characteristics were measured using scanning electron microscopy, thermal analysis, X-ray diffraction and FTIR spectroscopy. Secondly, effects of these treatments on the mechanical properties of lime mortars incorporating the chemically modified fibres were evaluated using 3 point bending tests. NaOH and EDTA treatments increase the crystallinity index of hemp fibres and increase the experimental rigidity of lime/natural fibres mortars. Treatments with polyethylene imine and a saturated lime solution do not induce any significant changes onto the mechanical properties. These results show that some specific chemical treatments have an impact onto the hemp/lime interfaces quality. The elaborated composite materials exhibit a higher rigidity and an improvement of the matrix /fibre charge transfer. However, the rupture stress is only slightly modified due to a relatively low fibre volumic content (10 %)

Fluorescence resonance energy transfer between organic dyes adsorbed onto nano-clay and Langmuir-Blodgett (LB) films

In this communication we investigate two dyes N,N' -dioctadecyl thiacyanine perchlorate (NK) and octadecyl rhodamine B chloride (RhB) in Langmuir and Langmuir-Blodgett (LB) films with or with out a synthetic clay laponite. Observed changes in isotherms of RhB in absence and presence of nano-clay platelets indicate the incorporation of clay platelets onto RhB-clay hybrid films. AFM image confirms the incorporation of clay in hybrid films. FRET was observed in clay dispersion and LB films with and without clay. Efficiency of energy transfer was maximum in LB films with clay.Comment: 15 pages 5 figures, 1 tabl

A novel system for water soluble protein encapsulation with high efficiency: “Micelles enhanced” polyelectrolyte capsules

Novel “micelles enhanced” polyelectrolyte (PE) capsules based on functional templates of hybrid calcium carbonate were fabricated. Evidences suggested that the structure of capsule wall was different from that of conventional PE capsules, and the wall permeability of these PE capsules changed significantly. Lysozyme, a positively charged protein in neutral solution, was studied as a model protein to be encapsulated into the “micelles enhanced” PE capsules. Confocal laser scanning microscope was used to observe the entrapping process in real time, while UV-Vis spectroscope and scanning force microscope measurements suggested the high efficiency of encapsulation. In addition, the fluorescence recovery after photobleaching technique was employed to determine the existence form of deposited molecules. Further studies showed even negatively charged water-soluble peptides or proteins can be encapsulated into these hybrid capsules by modulating the pH value in bulk solution under its isoelectronic point as well. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58582/1/31543_ftp.pd

Nanocomposite Microcontainers

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93507/1/adma_201201378_sm_suppl.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/93507/2/4597_ftp.pd

Polymeric Nanocapsule from Silica Nanoparticle@Cross-linked Polymer Nanoparticles via One-Pot Approach

A facile strategy was developed here to prepare cross-linked polymeric nanocapsules (CP nanocapsules) with silica nanoparticles as templates. The silica nanoparticle@cross-linked polymer nanoparticles were prepared by the encapsulation of the silica nanoparticles by the one-pot approach via surface-initiated atom transfer radical polymerization of hydroxyethyl acrylate in the presence ofN,N′-methylenebisacrylamide as a cross-linker from the initiator-modified silica nanoparticles. After the silica nanoparticle templates were etched with hydrofluoric acid, the CP nanocapsules with particle size of about 100 nm were obtained. The strategy developed was confirmed with Fourier transform infrared, thermogravimetric analysis and transmission electron microscopy

LC-HRMS data as a result of untargeted metabolomic profiling of human cerebrospinal fluid.

Cerebrospinal fluid (CSF) is a key body fluid that maintains the homeostasis in central nervous system (CNS). As a biofluid whose content reflects the brain metabolic activity, the CSF is analyzed in the context of neurological diseases and is rarely collected from healthy subjects. For this reason, the metabolite variation associated with general phenotypic characteristics such as gender and age have hardly ever been studied. Here we present the hydrophilic interaction liquid chromatography-high resolution mass spectrometry (HILIC-HRMS) data as a result of untargeted metabolomics analysis of a cohort of elderly cognitively healthy volunteers ( <i>n</i>  = 32). 146 unambiguously identified water soluble metabolites (using accurate mass, retention time and MS/MS matching against spectral libraries) were measured and their abundances across all the subjects depending on their gender are provided in this article. Data tables are available at https://data.mendeley.com/datasets/c73xtsd4s5/1. it's published on mendeley, the DOI is DOI:10.17632/c73xtsd4s5.1. The data presented in this article are related to the research article entitled "A global HILIC-MS approach to measure polar human cerebrospinal fluid metabolome: Exploring gender-associated variation in a cohort of elderly cognitively healthy subjects" (Gallart-Ayala et al., 2018, In press)

Encapsulation of a Concanavalin A/dendrimer glucose sensing assay within microporated poly (ethylene glycol) microspheres

Proper management of diabetes requires the frequent measurement of a patient’s blood glucose level. To create a long-term, minimally-invasive sensor that is sensitive to physiological concentrations of glucose a fluorescent glucose sensing assay using a competitive binding approach between fluorescently tagged Concanavalin-A (Con-A) and glycodendrimer is being developed. Until now, the essential step of effectively encapsulating this aggregative sensing assay while allowing a reversible response has yet to be reported. In this paper, a microporation technique is described in which microspheres are synthesized in a manner that creates fluid-filled pores within a poly (ethylene glycol) hydrogel. This dual-nature technique creates hydrophilic, biocompatible microcapsules in which the aggregative binding kinetics of the sensing assay within the pores are not constrained by spatial fixation in the hydrogel matrix. Confocal images displaying the localization of pockets filled with the assay within the polymeric matrix are presented in this paper. In addition, fluorescent responses to varying glucose concentrations, leaching studies, and long-term functionality of the encapsulated assay are demonstrated. To our knowledge, this is the first time that the Con-A/glycodendrimer assay has been shown to be reversible and repeatable within hydrogel spheres, including the display of functionality up to fourteen days under ambient conditions

TMEM106B and CPOX are genetic determinants of cerebrospinal fluid Alzheimer's disease biomarker levels

INTRODUCTION: Neurofilament light (NfL), chitinase-3-like protein 1 (YKL-40), and neurogranin (Ng) are biomarkers for Alzheimer's disease (AD) to monitor axonal damage, astroglial activation, and synaptic degeneration, respectively. METHODS: We performed genome-wide association studies (GWAS) using DNA and cerebrospinal fluid (CSF) samples from the EMIF-AD Multimodal Biomarker Discovery study for discovery, and the Alzheimer's Disease Neuroimaging Initiative study for validation analyses. GWAS were performed for all three CSF biomarkers using linear regression models adjusting for relevant covariates. RESULTS: We identify novel genome-wide significant associations between DNA variants in TMEM106B and CSF levels of NfL, and between CPOX and YKL-40. We confirm previous work suggesting that YKL-40 levels are associated with DNA variants in CHI3L1. DISCUSSION: Our study provides important new insights into the genetic architecture underlying interindividual variation in three AD-related CSF biomarkers. In particular, our data shed light on the sequence of events regarding the initiation and progression of neuropathological processes relevant in AD