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In the province of Quebec (Canada), paramedics use the esophageal tracheal Combitube (ETC) for prehospital airway management.Our main objective was to determine the proportion of patients with successful ventilation achieved after ETC use. Our secondary aim was to determine the number of ETC insertion attempts required to ventilate the patient.This is a retrospective cohort study. All patients who had ≥1 attempt to insert an ETC during prehospital care between January 1, 2017 and December 31, 2018 were included. Prehospital and in-hospital data were extracted. Successful ventilation was defined as thorax elevation, lung sounds on chest auscultation, or positive end-tidal capnography after ETC insertion.A total of 580 emergency medical services interventions (99.3% cardiac arrests) were included. Most patients were men (62.5%) with a mean age 67.0 years (SD 17.6 years), and 35 (13.1%) of the 298 patients transported to emergency department survived to hospital discharge. Sufficient information to determine whether ventilation was successful or not was available for 515 interventions. Ventilation was achieved during 427 (82.7%) of these interventions. The number of ETC insertion attempts was available for 349 of the 427 successful ETC use. Overall, the first insertion resulted in successful ventilation during 294 interventions for an overall proportion of first-pass success ranging between 57.1% and 72.1%.Proportions of successful ventilation and ETC first-pass success are lower than those reported in the literature with supraglottic airway devices. The reasons explaining these lower rates and their impact on patient-centered outcomes need to be studied.

Objective To provide an expert consensus definition of persistent postconcussion symptoms following a mild traumatic brain injury (mTBI). Participants Canadian healthcare professionals caring for patients with mTBI. Design Online Delphi process. Main measures A first Delphi round documented important dimensions or criteria to consider when defining persistent symptoms. Expert opinions were then resubmitted in 4 subsequent Delphi rounds and their relevance was rated using a 9-point Likert scale. An item with a median rating of 7 or more and a sufficient level of agreement were considered consensual. Results After 5 rounds, consensus was reached on a set of criteria that can be summarized as follows: presence of any symptom that cannot be attributed to a preexisting condition and that appeared within hours of an mTBI, that is still present every day 3 months after the trauma, and that has an impact on at least one sphere of a person's life. Conclusion This Delphi consensus proposes a set of criteria that support a more uniform definition of persistent symptoms in mild TBI among clinicians and researchers. This definition may help clinicians better identify persistent postconcussion symptoms and improve patient management.

Objective: To retrospectively analyse the use of imaging studies in the Emergency Department of community hospitals using evidence based guidelines and clinical judgement. Methods: Medical records of 661 patients who visited the Emergency Department (ED) in 2015 and underwent imaging studies were reviewed. The Canadian Association of Radiologists, American College of Radiologists and Choosing Wisely Canada guidelines were used to determine the appropriateness of imaging studies. The use of prior patient imaging, the rate at which studies were repeated and the respective impacts on patient management of the imaging studies were also examined. Results: Of the 1056 imaging studies reviewed, 228 (22%) were found to be clinical situations where no imaging study was indicated while 168 (16%) were considered a suboptimal choice of imaging study or modality. When no study was recommended, a positive impact on the diagnosis was noted in 105 (46%) cases and on patient management 83 (36%) times. Notably, 219 (21%) patients had a relevant examination performed in the last 30 days, and 147 (14%) reports noted that the results of the prior study also concurred with the imaging study evaluated. Conclusion: In this study, 228 (22%) radiographs and CT studies, excluding MVC related imaging and extremity imaging, were not indicated based on appropriateness criteria and consequently had a limited impact on patient management. This supports the need for increased clinical decision support for ED physicians, regional health information exchanges and consideration of Computerized Physician Order Entry in the ED with embedded appropriateness criteria at the point of ordering.

Conference of 43rd Annual Review of Progress in Quantitative Nondestructive Evaluation, QNDE 2016 ; Conference Date: 17 July 2016 Through 22 July 2016; Conference Code:126650; International audience; The use of composite structures has importantly increased because of their reduced weight, assembly simplification and excellent specific strength and stiffness. The multiple possibilities of their manufacturing allow today to integrate within a single structure multiple functions: design, mechanical strength, multi-material...These structures, by their geometric and structural complexity (anisotropy, attenuation and scattering noise), do not always allow the application of conventional ultrasound real-time methods. In this communication, the problem related to anisotropy is treated in a first part with an analysis of the influence of materials properties on the conventional array imaging methods. In the second part, anisotropy is taken into account in the Total Focusing Method (TFM) to improve the image quality in carbon fiber composite plates.

The behavior and budget of Mn, Cd and Cu in the Gironde estuary were investigated through data from both the water column (WC) and sediment depth profiles. In the estuarine freshwater reaches, Mn and Cd removal from and Cu addition to the dissolved phase occurs with a magnitude equivalent to 10%, 30% and 25% of their respective annual fluvial gross dissolved input, respectively. In the saline estuary, diffusive benthic outflow is the main source of dissolved Mn (74% of the total gross dissolved input within the estuary) to the WC. In contrast, Cd (96%) and Cu (89%) are mainly released into the dissolved phase of the WC from fluvial, estuarine and dredging-related particles through complexation (Cd) and organic carbon mineralization (Cu). Anthropogenic activities (sediment dredging) induce pore water inputs, particulate sulfide oxidation and sediment resuspension, significantly contributing to the metal budget of the WC. The related amounts of metals released could be equivalent to 20–50% (Cd) and up to 70% (Cu) of their respective net dissolved addition. Mass balances suggest that a large part of the metals previously released into the dissolved phase from processes within the estuary are removed by suspended particles due to (co-)precipitation of Fe/Mn (oxy)hydroxides and scavenging on autochthonous organic matter. On an annual basis, the Gironde estuary acts as a net sink of dissolved Mn, removing 60% of the dissolved fluvial inputs, and as a net source of dissolved Cd and Cu, contributing ∼ 85% and 20–45% to the dissolved Cd and Cu fluxes to the ocean.

International audience; Vertical distributions of dissolved major redox parameters, Mo and U from the water to the sediment were sampled in the salinity gradient of the Gironde estuary. In the water, sulfate and Mo are conservatively transported throughout the salinity gradient. In contrast, U shows a significant removal rate of 85 mu mol m(-2) a(-1) related to reductive sequestration of U in the anoxic sediment. Early diagenesis is highly transient and characterized by a three-zone regime related to three density layers functioning at different timescales. Excess of sulfate (up to 1 mM) is observed in the soft mud layer and is assigned to sulfide oxidation by both abiotic Mn- and Fe-oxide reduction and bacterial nitrate reduction. During early diagenesis, Mo and U are released in the sediment porewater from Mn- and Fe-oxides. In not-dredged anoxic sediments, authigenic precipitation of Mo and U with iron sulfides is proposed to explain their removal from solution. In contrast, in dredged sediments, authigenic precipitation of U is inhibited probably owing to the less effective reduction of soluble U(VI) to insoluble U(IV) due to oxidizing transient conditions. Mixing of anoxic sediment porewater with oxygenated water, due to (i) cyclical resuspension of the soft mud layer and (ii) dredging operations in the navigation channel, induces addition of dissolved sulfate (produced from diagenetic sulfide oxidation), Mo and U to the water. This addition is equivalent to 2% (sulfate), 5.5% (Mo) and 0.5% (U) of the dissolved fluvial inputs into the estuary for the natural resuspension, and 0.4% (Mo), less than 0.2% (sulfate, U) for dredge-induced resuspension. Addition of dissolved Mo and U, produced by oxidation of sulfide phases in the dredged sediments redeposited in dynamic environments, are equivalent to 12% (Mo) and 0.8% (U) of their respective fluvial inputs. Additional Mo and U inputs into the water originate from diffusive outflow from muddy sediments and are equivalent to 2% (Mo) and 0.3% (U) of their respective fluvial inputs. However, we show that all these dissolved inputs are scavenged by solid phases.

The last decade has seen the emergence of new ultrasonic array techniques going beyond the simple application of suitable delays (phased array techniques) for focusing purposes. Amongst these techniques, the particular method combining the so-called FMC (Full Matrix Capture) acquisition scheme with the synthetic focusing algorithm denoted by TFM (Total Focusing Method) has become popular in the NDE community. The 2014 WFNDEC ultrasonic benchmark aims at providing FMC experimental data for evaluating the ability of models to predict images obtained by TFM algorithms (or equivalent ones). In this paper we describe the benchmark and report comparisons obtained with the CIVA simulation software. The simulations and measurements are carried out on two steel blocks, one in carbon steel and another in stainless steel. The reference probe is a 64 elements linear array, with .5mm element width and a gap of .1mm, working at 5 MHz. The benchmark problem consists in predicting images of vertical and tilted notches located on plane or inclined backwalls. The notches have different heights and different ligaments. The images can be obtained considering different paths (direct echoes or corner echoes). For each notch, the full matrix capture (FMC) have been recorded in one unique position with the probe positioned such that than angle between the probe axis and the notch direction corresponds to 45°. The results are calibrated on the response of a 2mm side drilled hole. For each case, TFM images have been reconstructed for both experimental and simulated signals. The models used are those implemented in CIVA based on Kirchhoff approximation. Comparisons are reported and discussed.

Vertical profiles of heavy metals (Cd, Cu, Cr, Fe, Mn, Ni and Pb) in the particulate and dissolved phases and redox sensitive parameters (dissolved oxygen, nitrate, nitrite and ammonium) were analyzed for the first time in the continuum Maximum Turbidity Zone (MTZ)–Fluid Mud (FM; 50 g l 1

International audience; Vertical profiles from the water column, including the maximum turbidity zone (MTZ) to the consolidated sediment were sampled in September 2000 in the freshwater reaches of the Gironde Estuary during a complete neap tide-spring tide cycle. The vertical distributions of dissolved major redox parameters and metals (Mn, Fe, Cd, Cu, V, Co, Ni, Mo, and U) were determined. Reactive particulate metal fractions were also determined from selective leaching. The studied system is characterized by density layers functioning at different time-scales, consisting of two mobile layers, i.e., the liquid (LM) and the soft mud (SM), overlying consolidated sediments (CS). This results in a three-zone diagenetic regime where (1) O2 dynamics are fast enough to show depletion in the rapidly mixed LM sequence (tidal time-scale), (2) denitrification occurs on the weekly time-scale mixing SM sequence, and (3) the Mn, Fe, and sulfate cycling occurs in the CS layer (annual time-scale). The studied trace metals show differential behavior during early diagenesis: (1) Cd, Cu, and V are released into pore water preferentially from organic matter in the SM, (2) Co, Ni, and U are released in the CS from Mn and Fe oxides during reductive dissolution, and (3) Mo from both processes. Transient conditions (i.e., oscillations of redox fronts and reoxidation processes), due to the dynamics of the mobile layers, strongly influence the trace metal distributions as inducing resolubilization (Cd, Cu, and Mo). In the CS, authigenic metal phases accumulate, either by direct precipitation with sulfides (Cu, Cd) or co-precipitation with Fe-sulfides (Mo). Microbially mediated reduction of Fe oxides is proposed to control U removal from pore water by reduction of U(VI) to U(IV) at depth. However, a significant fraction of the trace metals is trapped in the sediment in exchangeable forms, and therefore is susceptible to be mobilized due to resuspension of estuarine sediment during strong river flood periods and/or dredging activities.

En Contrôle Non-Destructif (CND) par ultrasons, la plupart des systèmes d'acquisition disposent de modalités d’imagerie sophistiquées, comme la Total Focusing Method (TFM) ou le Plane Wave Imaging (PWI). Ces méthodes restent cependant restreintes à de l’imagerie 2D en raison du volume de données à traiter et du nombre d’opérations élevés en 3D. En effet, le nombre de points à reconstruire est généralement deux ordres de grandeur supérieurs en 3D. De plus, comme les sondes matricielles dédiées à l’imagerie 3D comportent au minimum 16 × 16 éléments, le nombre de signaux à traiter devient lui aussi problématique. Cette communication présente les derniers résultats d’une étude visant à développer un prototype d’imageur 4D pour le CND. Pour atteindre des cadences d’imagerie acceptables avec un nombre de voxels garantissant une haute résolution dans chacune des trois dimensions, les algorithmes de reconstruction dans le domaine de Fourier sont utilisés en raison de leur moindre complexité algorithmique. Nous montrons que leur implémentation peut être optimisée pour réduire la taille de l’espace mémoire requise, sans perdre en qualité d’image. Une étude comparative entre les deux méthodes temporelles, TFM et PWI, et leurs équivalents dans le domaine fréquentiel, nommés k-TFM et k-PWI, est présentée. Les performances des algorithmes en termes de qualité d'image, de cadence d’imagerie et de besoins en mémoire sont comparées. Les quatre méthodes sont évaluées expérimentalement en imageant un réseau 3D de porosités sphériques de 0,8 mm de diamètre contenues dans un échantillon en acier élaboré par fabrication additive à l’aide d’un procédé de fusion laser par lit de poudre.

This work aims to develop a methodology to image defects in composite structures by using Phased Array ultrasonic techniques. More specifically, the essential motivation lies in the difficulty of applying conventional ultrasonic methods for the control of thick and heterogeneous composite structures. Indeed, the application of these methods is more difficult in the presence of structural anisotropy where the velocity and the attenuation parameters change significantly depending on the ultrasound considered path. This could be more complicated in the presence of the viscoelastic properties frequency dispersion of the composite material. The studied imaging methods are applied in the case of heterogeneous and thick composite structures. First, the velocity and attenuation parameters of the elastic volume waves propagating in the composite under different incidences is determined. This work also allowed to go back to the viscoelastic characteristics by inverse method. The various parameters found by direct and inverse methods are then integrated into the direct ultrasound path calculation model to correct the anisotropy effects in the Total Focusing Method (TFM) and Plane Wave Imaging (PWI) imagery and thus to study the possibilities of improvement of the detection and characterization of defects that may exist within the studied composite structures. Finally, it is important to emphasize that this same work discusses the need of the tensor of elasticity for an optimal characterization of the anisotropy. For this purpose, a comparison with a simplified model involving group velocity is proposed.; Ce travail de thèse a pour objectif de développer une méthodologie visant à imager les défauts dans les structures composites moyennant les ultrasons multiéléments. Plus précisément, la motivation essentielle réside dans la difficulté d’application des méthodes ultrasonores conventionnelles pour le contrôle de structures composites épaisses et hétérogènes. En effet, l’application de ces méthodes est d’autant plus difficile en présence d’anisotropie structurelle où les paramètres vitesse et atténuation changent de façon importante en fonction du trajet ultrasonore considéré. Cela pourrait même se compliquer en présence de dispersion fréquentielle des propriétés viscoélastiques du matériau composite. Les méthodes d’imagerie étudiées sont appliquées dans le cas de structures composites hétérogènes de forte épaisseur. Dans un premier temps, les paramètres vitesse et atténuation des ondes élastiques de volume se propageant dans le composite sous différentes incidences ont été déterminées.Ce travail a également permis de remonter aux caractéristiques viscoélastiques par méthode inverse.Les différents paramètres trouvés par méthodes directe et inverse sont ensuite intégrés au modèle direct de calcul de trajets ultrasonores pour corriger les effets d’anisotropie dans l’imagerie Total Focusing Method (TFM) et Plane Wave Imaging (PWI) et étudier ainsi les possibilités d’amélioration de la détection et de la caractérisation des défauts pouvant exister au sein des structures composites étudiées. Enfin, il est important de souligner que ce même travail discute de la nécessité de connaître le tenseur d’élasticité pour une prise en compte optimale de l’anisotropie. À cet effet, une comparaison avec un modèle simplifié mettant en jeu les vitesses de groupe est proposée.

This thesis is related to ultrasonic non-destructive testing and detection of defects in complex materials. Improvements of the Total Focusing Method (TFM) when images are corrupted bya high noise level are proposed. Three main points are developed : the optimization of the acquisition of the impulse response matrix K(t) using virtual sources or spatial coding ; the separation of subspaces associated with the signal and the noise using the decomposition of the time reversal operator (DORT) ; and the image formation in the time domain with TFM after the signal denoising. Two different types of noise are considered : the coherent noise linked to the heterogeneous structure of a coarse-grained steel, and the incoherent electronic noise introduced by the signal acquisition system in the case of a high attenuating viscoelastic material.The study also focuses on imaging artifacts generated by surface waves which propagate alonga contact array probe. The singular values associated with these guided modes are modeled tofacilitate the interpretation of the decomposition of the transfer matrix ˆK( f ), and to filter theartifacts. When the region of interest is far from the probe axis, an alternative approach to singular vector back-propagation is proposed in order to improve the quality of images formedin the frequency domain. This approach consists in combining the DORT method with the topologica limaging. After the noise and surface waves filtering, the TFM images are comparedwith those calculated by the singular vector back-propagation or by the topological imaging.Then, this work focuses on the detection in a polyethylene pipe of high viscoelastic attenuation introducing unwanted noise in the TFM images. To record the K(t) matrix while increasingthe ultrasonic penetration depth, two Hadamard pseudo-codes are developed, and the gainsare theoretically and experimentally justified. A theoretical model of the singular values associated with the noise is then proposed to facilitate the defect response extraction from thetransfer matrix ˆK( f ). Finally, a filtering procedure for Plane Wave Imaging (PWI) is proposed,which combines the advantages of virtual sources (used in the coarse-grained steel) and coded transmissions (used in the polyethylene), thus giving excellent performances in complex materials; Cette thèse porte sur le contrôle non destructif par ultrasons et la détection de défauts dans des matériaux complexes. Elle apporte des améliorations à l’imagerie Total Focusing Method(TFM) lorsque les images sont altérées par un haut niveau de bruit. Trois points essentiels sont abordés : l’optimisation de l’acquisition de la matrice des réponses impulsionnelles K(t) avec des sources virtuelles ou des émissions codées en amplitude ; la séparation des sous-espaces vectoriels associés au signal et au bruit avec la Décomposition de l’Opérateur de Retournement Temporel (DORT) ; et la formation d’image dans le domaine temporel avec TFM après le débruitage des signaux. La thèse s’intéresse au bruit cohérent lié à la structure hétérogène d’un acier à gros grains, puis au bruit électronique incohérent introduit par la chaîne d’acquisition des signaux dans le cas d’un matériau viscoélastique très atténuant. Ce travail s’intéresse aussi aux artefacts d’imagerie engendrés par les ondes de surface se propageant le long d’un capteur multiéléments au contact. Les valeurs singulières associées à ces modes guidés sont modélisées pour faciliter l’interprétation de la décomposition de la matrice de transfert Kˆ(f)et filtrer les artefacts d’imagerie. Lorsque la zone d’intérêt est éloignée de l’axe central du capteur,une approche alternative à la rétro-propagation de vecteurs singuliers est proposée pour améliorer la qualité des images formées dans le domaine fréquentiel. Elle consiste à combinerla méthode DORT avec l’imagerie topologique. Après filtrage du bruit et des ondes de surface,les images TFM sont comparées avec celles calculées par rétro-propagation ou par imagerie topologique. Ensuite, ce travail s’intéresse à la détection dans un tube en polyéthylène dont l’atténuation viscoélastique fait apparaître un fort bruit électronique sur les images TFM. Pour enregistrer la matrice K(t) en augmentant la profondeur de pénétration des ultrasons, deux pseudo-codages de Hadamard sont développés, et les gains apportés sont justifiés théoriquement et expérimentalement. Un modèle théorique des valeurs singulières associées au bruit est ensuite proposé pour faciliter l’extraction de la réponse du défaut dans la matrice Kˆ(f). Enfin, la thèse introduit une méthode de filtrage pour Plane Wave Imaging (PWI) offrant de bonnes performances dans les matériaux complexes car elle cumule les avantages de sources virtuelles (utilisées dans l’acier) et des émissions codées (utilisées dans le polyéthylène)