1,047 research outputs found

    An Analysis of Respiration with the Smart Sensor SENSIRIB in Patients Undergoing Thoracic Surgery

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    : The paper examines the problem of respiration monitoring with easily wearable instrumentation by using a smart device that is properly designed and implemented with small and light components. The practical implementation is presented both in practical aspects and from experimental results by following a properly defined method with a medical-like protocol and specific procedure of testing. The results of a statistically significant campaign of experimental tests are reported with the characteristic data from the angles and acceleration components of a sensed rib both to validate the smart device and the procedure for respiration monitoring

    Model-based fault detection in diesel engines air-path

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    Cette thèse a pour but l étude de la détection basée sur modèle de défauts pour lesmoteurs Diesel produits en grande série. La nécessité d une surveillance continue del état de santé des véhicules est maintenant renforcée par la législation Euro VI sur lesémissions polluantes, qui sera probablement rendue encore plus contraignante dans sesprochaines révisions. Dans ce contexte, le développement de stratégies robustes, faciles àcalibrer et valides pour des systèmes dispersés (car produits en grande série) procureraitun avantage considérable aux constructeurs automobile. L étude développée ici tentede répondre à ces besoins en proposant une méthodologie générique. On utilise desobservateurs adaptatifs locaux pour des systèmes scalaires non linéaires et affines parrapport à l état, pour résoudre les problèmes de la détection de défauts, de son isolationet de son estimation d une façon compacte. De plus, les incertitudes liées aux biais demesure et de modèle et aux dérives temporelles nécessitent d améliorer les méthodes dedétection par l utilisation de seuils robustes pour éviter les fausses détections. Dans cettethèse, on propose un seuil variable basé sur la condition d observabilité du paramètreimpacté par le défaut et sur une étude de sensibilité par rapport aux incertitudes surles entrées ou sur le modèle. Cette méthode permet, entre autres, de fournir un outild analyse pour la sélection des conditions de fonctionnement du système pour lesquelsle diagnostic est plus fiable et plus robuste par rapport aux incertitudes sur les entrées.L approche présentée a été appliquée avec succès et validée de façon expérimentale surun moteur Diesel pour le problème de détection de fuite dans le système d admissiond air, puis dans un environnement de simulation pour le problème de détection dedérive d efficacité turbine. On montre ainsi ses avantages en termes de fiabilité dedétection, d effort de calibration, et pour l analyse des conditions de fonctionnementmoteur adaptées au diagnostic.The study of model-based fault detection for mass production Diesel engines isthe aim of this thesis. The necessity of continuous vehicles health monitoring is nowenforced by the Euro VI pollutant legislation, which will probably be tightened in itsfuture revisions. In this context developing a robust strategy that could be easilycalibrated and work with different systems (due to production variability) would bea tremendous advantage for car manufacturers. The study developed here tries toanswer to those necessities by proposing a generic methodology based on local adaptiveobservers for scalar nonlinear state-affine systems. The fault detection, isolation andestimation problems are thus solved in a compact way. Moreover, the uncertaintiesdue to measurement or model biases and time drifts lead to the necessity of improvingthe detection methodology by the use of robust thresholds that could avoid undesiredfalse alarms. In this thesis a variable threshold is proposed based on the observabilitycondition and the sensitivity analysis of the parameter impacted by the fault withrespect to input or model uncertainties. This approach allows, among other things, tobe used as an analysis tool for the individuation of the system operating points for whichthe diagnosis is more reliable and more robust to inputs uncertainties. The discussedapproach has been successfully implemented and experimentally tested on a real Dieselengine for the intake leak detection and for the turbine efficiency loss drift detectionin a co-simulation environment showing its advantages in term of detection reliability,calibration effort and engines diagnosis operating condition analysis.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

    Anti-carbamylated protein antibodies as a new biomarker of erosive joint damage in systemic lupus erythematosus

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    Background: The application of more sensitive imaging techniques, such as ultrasonography (US), changed the concept of non-erosive arthritis in systemic lupus erythematosus (SLE), underlining the need for biomarkers to identify patients developing the erosive phenotype. Anti-citrullinated peptide antibodies (ACPA), associated with erosions in inflammatory arthritis, have been identified in about 50% of patients with SLE with erosive arthritis. More recently, anti-carbamylated proteins antibodies (anti-CarP) have been associated with erosive damage in rheumatoid arthritis. We aimed to assess the association between anti-CarP and erosive damage in a large SLE cohort with joint involvement. Methods: We evaluated 152 patients (male/female patients 11/141; median age 46years, IQR 16; median disease duration 108months, IQR 168). All patients underwent blood draw to detect rheumatoid factor (RF) and ACPA (commercial enzyme-linked immunosorbent assay (ELISA) kit), and anti-CarP ("home-made" ELISA, cutoff 340aU/mL). The bone surfaces of the metacarpophalangeal and proximal interphalangeal joints were assessed by US: the presence of erosions was registered as a dichotomous value (0/1), obtaining a total score (0-20). Results: The prevalence of anti-CarP was 28.3%, similar to RF (27.6%) and significantly higher than ACPA (11.2%, p=0.003). Erosive arthritis was identified in 25.6% of patients: this phenotype was significantly associated with anti-CarP (p=0.004). Significant correlation between anti-CarP titer and US erosive score was observed (r=0.2, p=0.01). Conclusions: Significant association was identified between anti-CarP and erosive damage in SLE-related arthritis, in terms of frequency and severity, suggesting that these antibodies can represent a biomarker of severity in patients with SLE with joint involvement

    High-fidelity and polarization insensitive universal photonic processors fabricated by femtosecond laser writing

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    Universal photonic processors (UPPs) are fully programmable photonic integrated circuits that are key components in quantum photonics. With this work, we present a novel platform for the realization of low-loss, low-power and high-fidelity UPPs based on femtosecond laser writing (FLW) and compatible with a large wavelength spectrum. In fact, we demonstrate different UPPs, tailored for operation at 785 nm and 1550 nm, providing similar high-level performances. Moreover, we show that standard calibration techniques applied to FLW-UPPs result in Haar random polarization independent photonic transformations implemented with average amplitude fidelity as high as 0.9979 at 785 nm (0.9970 at 1550 nm), with the possibility of increasing the fidelity over 0.9990 thanks to novel optimization algorithms. Besides being the first demonstrations of polarization-transparent UPPs, these devices show the highest level of control and reconfigurability ever reported for a FLW circuit. These qualities will be greatly beneficial to applications in quantum information processing

    Model-based Adaptive Observers for Intake Leakage Detection in Diesel Engines

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    International audienceThis paper studies the problem of diesel engine diagnosis by means of model-based adaptive observers. The problem is motivated by the needs of garante high-performance engine behavior and in particular to respect the environmentally-based legislative regulations. The complexity of the intake systems of this type of engine makes this task particularly arduous and requires to constantly monitor and diagnose the engine operation. The development and application of two different nonlinear adaptive observers for intake leakage estimation is the goal of this work. The proposed model-based adaptive observers approach allows estimating a variable that is directly related to the presence of leakage, e.g., hole radius. Monitoring and diagnostic tasks, with this kind of approach, are straightforward. Two different approaches, whose main difference is on observer adaptation law structure are studied. One approach is based on fixed gains while the other method has variable gain. The paper also includes a comparative study of the two methods in simulations using advanced diesel engine professional simulator AMEsim

    Prevalence, sensitivity and specificity of antibodies against carbamylated proteins in a monocentric cohort of patients with rheumatoid arthritis and other autoimmune rheumatic diseases

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    Antibodies against carbamylated proteins (anti-CarP) have been recently identified in the sera of patients with rheumatoid arthritis (RA). The objective of the study was to evaluate the prevalence, sensitivity and specificity of anti-CarP compared to anti-citrullinated peptide antibodies (ACPA) and rheumatoid factor (RF), replicating the existing data in a large cohort of Italian patients with RA and extending the evaluation to other autoimmune rheumatic diseases (AIRDs)

    How skill expertise shapes the brain functional architecture: an fMRI study of visuo-spatial and motor processing in professional racing-car and naïve drivers

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    The present study was designed to investigate the brain functional architecture that subserves visuo-spatial and motor processing in highly skilled individuals. By using functional magnetic resonance imaging (fMRI), we measured brain activity while eleven Formula racing-car drivers and eleven ‘naïve’ volunteers performed a motor reaction and a visuo-spatial task. Tasks were set at a relatively low level of difficulty such to ensure a similar performance in the two groups and thus avoid any potential confounding effects on brain activity due to discrepancies in task execution. The brain functional organization was analyzed in terms of regional brain response, inter-regional interactions and blood oxygen level dependent (BOLD) signal variability. While performance levels were equal in the two groups, as compared to naïve drivers, professional drivers showed a smaller volume recruitment of task-related regions, stronger connections among task-related areas, and an increased information integration as reflected by a higher signal temporal variability. In conclusion, our results demonstrate that, as compared to naïve subjects, the brain functional architecture sustaining visuo-motor processing in professional racing-car drivers, trained to perform at the highest levels under extremely demanding conditions, undergoes both ‘quantitative’ and ‘qualitative’ modifications that are evident even when the brain is engaged in relatively simple, non-demanding tasks. These results provide novel evidence in favor of an increased ‘neural efficiency’ in the brain of highly skilled individuals

    It’s not all in your car: functional and structural correlates of exceptional driving skills in professional racers

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    Driving is a complex behavior that requires the integration of multiple cognitive functions. While many studies have investigated brain activity related to driving simulation under distinct conditions, little is known about the brain morphological and functional architecture in professional competitive driving, which requires exceptional motor and navigational skills. Here, 11 professional racing-car drivers and 11 “naïve” volunteers underwent both structural and functional brain magnetic resonance imaging (MRI) scans. Subjects were presented with short movies depicting a Formula One car racing in four different official circuits. Brain activity was assessed in terms of regional response, using an Inter-Subject Correlation (ISC) approach, and regional interactions by mean of functional connectivity. In addition, voxel-based morphometry (VBM) was used to identify specific structural differences between the two groups and potential interactions with functional differences detected by the ISC analysis. Relative to non-experienced drivers, professional drivers showed a more consistent recruitment of motor control and spatial navigation devoted areas, including premotor/motor cortex, striatum, anterior, and posterior cingulate cortex and retrosplenial cortex, precuneus, middle temporal cortex, and parahippocampus. Moreover, some of these brain regions, including the retrosplenial cortex, also had an increased gray matter density in professional car drivers. Furthermore, the retrosplenial cortex, which has been previously associated with the storage of observer-independent spatial maps, revealed a specific correlation with the individual driver's success in official competitions. These findings indicate that the brain functional and structural organization in highly trained racing-car drivers differs from that of subjects with an ordinary driving experience, suggesting that specific anatomo-functional changes may subtend the attainment of exceptional driving performance

    Autologous Periosteum-Derived Micrografts and PLGA/HA Enhance the Bone Formation in Sinus Lift Augmentation

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    Sinus lift augmentation is a procedure required for the placement of a dental implant, whose success can be limited by the quantity or quality of available bone. To this purpose, the first aim of the current study was to evaluate the ability of autologous periosteum-derived micrografts and Poly(lactic-co-glycolic acid) (PLGA) supplemented with hydroxyl apatite (HA) to induce bone augmentation in the sinus lift procedure. Secondly, we compared the micrograft's behavior with respect to biomaterial alone, including Bio-Oss® and PLGA/HA, commercially named Alos. Sinus lift procedure was performed on 24 patients who required dental implants and who, according to the study design and procedure performed, were divided into three groups: group A (Alos + periosteum-derived micrografts); group B (Alos alone); and group C (Bio-Oss® alone). Briefly, in group A, a small piece of periosteum was collected from each patient and mechanically disaggregated by Rigenera® protocol using the Rigeneracons medical device. This protocol allowed for the obtainment of autologous micrografts, which in turn were used to soak the Alos scaffold. At 6 months after the sinus lift procedure and before the installation of dental implants, histological and radiographic evaluations in all three groups were performed. In group A, where sinus lift augmentation was performed using periosteum-derived micrografts and Alos, the bone regeneration was much faster than in the control groups where it was performed with Alos or Bio-Oss® alone (groups B and C, respectively). In addition, the radiographic evaluation in the patients of group A showed a radio-opacity after 4 months, while after 6 months, the prosthetic rehabilitation was improved and was maintained after 2 years post-surgery. In summary, we report on the efficacy of periosteum-derived micrografts and Alos to augment sinus lift in patients requiring dental implants. This efficacy is supported by an increased percentage of vital mineralized tisssue in the group treated with both periosteum-derived micrografts and Alos, with respect to the control group of Alos or Bio-Oss® alone, as confirmed by histological analysis and radiographic evaluations at 6 months from treatment
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