Calcul intensif pour la modélisation du milieu interstellaire

Calcul intensif pour la modélisation du milieu interstellair

0218: Comparison of transvenous versus surgical implantation of left ventricular lead for cardiac resynchronization therapy

BackgroundApproximately 1% of the adult population have heart failure with reduced ejection fraction. Since the 1980s, therapeutic advances in this field have been significant, particularly through the development of cardiac resynchronization therapy (CRT). However, transvenous implantation of the left ventricular (LV) lead is unsuccessful in 5 - 15% of patients. For this group, surgical placement of LV lead is an alternative.ObjectiveCompare the effects of transvenous versus surgical implantation of the LV lead in CRT.MethodsWe included 100 consecutive patients who had received CRT in our centre between January 2008 and July 2012 in a retrospective observational study. Twelve patients who had failed transvenous implantation of LV lead had a surgical placement.ResultsPopulation characteristics were a mean age of 66±11 years, 16% female, New York Heart Association class 2.9±0.5, 45% ischemic cardiomyopathy, left ventricular ejection fraction (LVEF) 24±7%, QRS width 165±23ms. There were no major difference in preoperative variables between two groups except sex category (12.5% female in transvenous group versus 42% in surgical group, p=0.022). During a mean follow-up of 508±429 days, the improvements seen in all variables showed no difference between the groups. At six months, 77% of patients had improved at least one class of their dyspnea stage, LVEF improved significantly (24±7% versus 36±10% at six months).ConclusionsSurgical placement of LV lead offers similar benefits as compared with transvenous implantation

Ouverture d'une consultation de cardiogénétique au Centre Hospitalier de Reims

REIMS-BU Santé (514542104) / SudocSudocFranceF

Imagerie acousto-optique de milieux diffusants épais par détection photoréfractive

Imager un milieu diffusant épais par voie optique interdit l utilisation des techniques d imagerie optique conventionnelles du fait de la faiblesse du signal balistique. L imagerie acousto-optique de la lumière diffusée permet d obtenir une imagerie de l absorption optique locale avec une résolution transverse millimétrique. Elle s appuie sur un faisceau acoustique focalisé qui engendre par interaction acousto-optique une modulation de la phase du champ lumineux diffusé. Les détections cohérentes du signal optique modulé acoustiquement se trouvent cependant souvent limitées par la faiblesse de leur étendue optique ou de leur bande passante. Notre expérimentation s appuie sur une détection photoréfractive hétérodyne reposant sur une holographie dynamique à 1064nm construite autour d un cristal photoréfractif massif d Arsenure de Gallium, pour pallier à ces deux limitations. Par ailleurs, pour obtenir une résolution millimétrique selon l axe de propagation ultrasonore, nous avons développé une technique de modulation aléatoire de phase du faisceau acoustique et du faisceau lumineux qui crée une zone de cohérence temporelle contrôlée au sein même du milieu diffusant. La mise en oeuvre de ces techniques ont permis d imager avec des résolutions millimétriques des échantillons diffusants de caractéristiques proches des tissus biologiques sur une épaisseur de 3cm.PARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Insuffisance rénale chronique et pathologies cardio-vasculaires (suivi prospectif clinique, biologique et échocardiographique d'une cohorte de 71 patients stade 4 (clairance de 15 a 29 ml/min)

REIMS-BU Santé (514542104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

An adaptative filtering method to evalute normal vectors and surface areas of 3d objects. Application to snow images from X-ray tomography

International audienceEstimating the normal vector field on the boundary of discrete 3D objects is essential for rendering and image measurement problems. Most of the existing algorithms do not provide an accurate determination of the normal vector field for shapes that present edges. We propose here a new and simple computational method in order to obtain accurate results on all types of shapes whatever their local convexity degree is. The presented method is based on the gradient vector field analysis of the object distance map. This vector field is adaptively filtered around each surface voxel using angle and symmetry criteria, so that as many relevant contributions as possible are accounted for. This optimizes the smoothing of digitization effects while preserving relevant details of the processed numerical object. Thanks to the precise normal field obtained, a projection method can be proposed to derive immediately the surface area from a raw discrete object. An empirical justification of the validity of such an algorithm in the continuous limit is also provided. Some results on simulated data and snow images from X-ray tomography are presented, compared to the Marching Cubes and Convex Hull results and discussed

Influence of healing time on the mechanicalproperties of an implanted mesh

International audienc