Étude empirique de huit cas d'application de la réalité augmentée spatiale pour la communication événementielle

RÉSUMÉ : Le secteur des Nouvelles Technologies de l’Information et des Communications (NTIC) a créé de nouvelles attentes chez les consommateurs (mobilité, recherche de lien social, besoin de divertissement…) et a profondément bouleversé les schémas de communication traditionnelle. Pour répondre à ces nouvelles problématiques, de nouvelles approches de médiation ont fait leur apparition au sein des agences de communications. Depuis quelques années, l’usage de la Réalité Augmentée Spatiale (RAS), consistant à faire coexister spatialement et temporellement un monde virtuel avec le monde réel pour l'utilisateur placé dans l'environnement de réalité mixte, a permis aux agences de communication de mettre en place un nouveau modèle d’affaires, misant sur la dimension virale qu’ont les réalisations innovantes sur les réseaux sociaux. Certaines vidéos mettant en scène la dimension spectaculaire de la RAS à des fins publicitaires ont ainsi été partagées et visionnées plusieurs millions de fois, permettant de maximiser la diffusion du message publicitaire à moindre coût, grâce au partage des internautes. Le problème soulevé par cette recherche est le manque de littérature opérationnelle concernant ces prestations de services émergents. Les tâches de conception sont nombreuses, contextuelles et interconnectées, et impliquent plusieurs corps de métiers. Aussi, il est difficile de spécifier les fonctions d’usages de l’objet à concevoir principalement à cause de l’absence d’objet préexistant ou de client capable de formuler une demande claire. Il s’agit pour les acteurs de ces projets de conception innovante de créer des environnements de réalité mixte dans un environnement non contrôlé. Dans le cadre d'une communication événementielle nécessitant le développement d'un système de de Réalité Augmentée Spatiale (SRAS), cette recherche a pour objectif de répondre aux questions suivantes : quelles sont les tâches à faire, quelle est la démarche à suivre, à quels types de spécialistes faut-il faire appel, quels sont les outils informatiques à utiliser, et quels défis pratiques se posent? Nous espérons ainsi contribuer à l’amélioration des processus de développement et à la gestion de la connaissance associée à un champ d’applications industrielles émergentes. La méthode retenue pour ce projet de recherche est celle de la Recherche-Action (R-A). Elle a été réalisée dans le cadre d’un partenariat industriel de deux ans avec une agence de communication de nouveaux médias spécialisée dans les installations de projections à grande échelle et les expériences immersives et interactives. Au cours de ces deux années en milieu pratique, nous avons activement collaboré au développement de huit installations de RAS pour des cas de communication événementielle. La première contribution de ce mémoire, à travers la présentation de huit cas de projets industriels d’augmentations spatiales, est de permettre la réutilisation des processus opérationnels mis en place et des solutions techniques développées éprouvées par la pratique. Pour chaque cas, nous explicitons le mandat du commanditaire, le concept et le scénario d’augmentation retenu pour répondre aux besoins d'estime et d'usage, et les stratégies employées pour assurer la cohérence spatiale et temporelle de l'augmentation de la réalité. Ces cas permettront ainsi aux concepteurs d’appréhender les propriétés hédoniques et pragmatiques associées à ces produits émergents et représentent autant de pistes pour relever les défis qui se poseront lors de la conception de nouveaux SRAS. La deuxième contribution de ce mémoire est la proposition d'une démarche de conception et de réalisation dédiée. Pour cela, nous nous sommes basés sur nos expériences pratiques, nos observations et l’analyse du développement de ces huit produits de RAS. Nous explicitons la pluralité des expertises nécessaires, les tâches de conception génériques des différents acteurs et leurs interconnexions. Nous avons formulé des lignes directrices pour les tâches associées à l’augmentation numérique d’un environnement physique en contexte industriel (conception de l’expérience, conception matérielle et logicielle) et pour l’établissement du cadre de référence, permettant de faire le pont entre les dimensions réelle et virtuelle durant le développement. La troisième contribution de ce mémoire est l'analyse comparative de différents processus opérationnels pour la RAS par projection vidéo et des outils informatiques utilisables. Nous en avons utilisé certains pour des besoins réels de projets d’augmentation, ce qui nous a permis d’identifier leurs limites opérationnelles, de les indexer, et de formuler des conseils concernant leur utilisation contextuelle. Ce projet de recherche vise ainsi globalement à regrouper et structurer le savoir-faire technique et méthodique d'experts pionniers de l'usage de la RAS en tant que prestation de service de communication.----------ABSTRACT : The sector of New Technologies of Information and Communications (NICT) has created new expectations among consumers (mobility, social link seeking, entertainment need...) and profoundly disrupted traditional strategies for communication. To meet these new challenges, new approaches have appeared in communications agencies. In recent years, the use of Spatial Augmented Reality (SAR), consisting in overlaying an object or a physical environment with a digital layer of video, enabled agencies to establish a new business model, focusing on the viral dimension of innovative achievements on social networks. Indeed, some videos featuring the spectacular dimension of SAR for advertising purposes have been shared and viewed millions of times, maximizing the dissemination of the advertisement cost. The problem raised by this research is the lack of literature on the operational aspects of those emerging services and the design process of Spatial Augmented Reality Systems (SARS). Tasks are numerous, contextual, interconnected and involve several types of expertise. Our study is intended to help the designers of these projects by structuring the technical and methodical know-how. We hope to contribute to improve the development processes and the knowledge management associated with an emerging field of industrial applications. The method used for this research is Action Research. It was conducted as part of an industrial two-year partnership with a communication agency specializing in new media installations and large-scale projections experiences. During these two years in practice environment, we worked on the development of eight SARS used for event communication cases. The first contribution of this memoir is to present these eight cases of industrial projects to enable the reuse of processes and technical solutions that were developed. We described the mandate of the sponsor, the concept and scenario retained to meet his needs, and the strategies used to ensure spatial and temporal coherence of the augmentation of the reality for the end user. These cases should allow designers to understand the pragmatic and hedonic properties associated with these emerging products and represent examples for facing their own challenges when designing a specific SARS. The second contribution of this memoir is to suggest an approach to design SARS, based on our practical experience, our observations and the iterative development of these eight products. We expose the plurality of expertise that was required, the generic design tasks of the various actors and their interconnections. We have developed guidelines for the design tasks associated with the augmentation of a physical environment in an industrial context (experience design, hardware and software design) and have established a reference framework, building a bridge between the real and virtual dimension during the development of SARS. The third contribution of this memoir is a comparative analysis of different processes for projection mapping and of different computer tools used to fill the needs of this sector. We used some of them in the eight projects, which allowed us to identify their operational limits and give advice on their contextual uses

Estimation of Unbound Carboplatin Clearance From Total Plasma Concentrations as a Means of Facilitating Therapeutic Drug Monitoring

International audienc

Archetype Analysis Identifies Distinct Profiles in Renal Transplant Recipients with Transplant Glomerulopathy Associated with Allograft Survival

BACKGROUND: Transplant glomerulopathy, a common glomerular lesion observed after kidney transplant that is associated with poor prognosis, is not a specific entity but rather the end stage of overlapping disease pathways. Its heterogeneity has not been precisely characterized to date. METHODS: Our study included consecutive kidney transplant recipients from three centers in France and one in Canada who presented with a diagnosis of transplant glomerulopathy (Banff cg score ≥1 by light microscopy), on the basis of biopsies performed from January of 2004 through December of 2014. We used an unsupervised archetype analysis of comprehensive pathology findings and clinical, immunologic, and outcome data to identify distinct groups of patients. RESULTS: Among the 8207 post-transplant allograft biopsies performed during the inclusion period, we identified 552 biopsy samples (from 385 patients) with transplant glomerulopathy (incidence of 6.7%). The median time from transplant to transplant glomerulopathy diagnosis was 33.18 months. Kidney allograft survival rates at 3, 5, 7, and 10 years after diagnosis were 69.4%, 57.1%, 43.3%, and 25.5%, respectively. An unsupervised learning method integrating clinical, functional, immunologic, and histologic parameters revealed five transplant glomerulopathy archetypes characterized by distinct functional, immunologic, and histologic features and associated causes and distinct allograft survival profiles. These archetypes showed significant differences in allograft outcomes, with allograft survival rates 5 years after diagnosis ranging from 88% to 22%. Based on those results, we built an online application, which can be used in clinical practice on the basis of real patients. CONCLUSIONS: A probabilistic data-driven archetype analysis approach applied in a large, well defined multicenter cohort refines the diagnostic and prognostic features associated with cases of transplant glomerulopathy. Reducing heterogeneity among such cases can improve disease characterization, enable patient-specific risk stratification, and open new avenues for archetype-based treatment strategies and clinical trials optimization

Prediction system for risk of allograft loss in patients receiving kidney transplants: international derivation and validation study

OBJECTIVE: To develop and validate an integrative system to predict long term kidney allograft failure. DESIGN: International cohort study. SETTING: Three cohorts including kidney transplant recipients from 10 academic medical centres from Europe and the United States. PARTICIPANTS: Derivation cohort: 4000 consecutive kidney recipients prospectively recruited in four French centres between 2005 and 2014. Validation cohorts: 2129 kidney recipients from three centres in Europe and 1428 from three centres in North America, recruited between 2002 and 2014. Additional validation in three randomised controlled trials (NCT01079143, EudraCT 2007-003213-13, and NCT01873157). MAIN OUTCOME MEASURE: Allograft failure (return to dialysis or pre-emptive retransplantation). 32 candidate prognostic factors for kidney allograft survival were assessed. RESULTS: Among the 7557 kidney transplant recipients included, 1067 (14.1%) allografts failed after a median post-transplant follow-up time of 7.12 (interquartile range 3.51-8.77) years. In the derivation cohort, eight functional, histological, and immunological prognostic factors were independently associated with allograft failure and were then combined into a risk prediction score (iBox). This score showed accurate calibration and discrimination (C index 0.81, 95% confidence interval 0.79 to 0.83). The performance of the iBox was also confirmed in the validation cohorts from Europe (C index 0.81, 0.78 to 0.84) and the US (0.80, 0.76 to 0.84). The iBox system showed accuracy when assessed at different times of evaluation post-transplant, was validated in different clinical scenarios including type of immunosuppressive regimen used and response to rejection therapy, and outperformed previous risk prediction scores as well as a risk score based solely on functional parameters including estimated glomerular filtration rate and proteinuria. Finally, the accuracy of the iBox risk score in predicting long term allograft loss was confirmed in the three randomised controlled trials. CONCLUSION: An integrative, accurate, and readily implementable risk prediction score for kidney allograft failure has been developed, which shows generalisability across centres worldwide and common clinical scenarios. The iBox risk prediction score may help to guide monitoring of patients and further improve the design and development of a valid and early surrogate endpoint for clinical trials. TRIAL REGISTRATION: Clinicaltrials.gov NCT03474003.status: publishe

Long term outcomes of transplantation using kidneys from expanded criteria donors: prospective, population based cohort study

International audienceObjectives To assess the long term outcomes of transplantation using expanded criteria donors (ECD; donors aged ≥60 years or aged 50-59 years with vascular comorbidities) and assess the main determinants of its prognosis.Design Prospective, population based cohort study.Setting Four French referral centres.Participants Consecutive patients who underwent kidney transplantation between January 2004 and January 2011, and were followed up to May 2014. A validation cohort included patients from another four referral centres in France who underwent kidney transplantation between January 2002 and December 2011.Main outcome measures Long term kidney allograft survival, based on systematic assessment of donor, recipient, and transplant clinical characteristics; preimplantation biopsy; and circulating levels of donor specific anti-HLA (human leucocyte antigen) antibody (DSA) at baseline.Results The study included 6891 patients (2763 in the principal cohort, 4128 in the validation cohort). Of 2763 transplantations performed, 916 (33.2%) used ECD kidneys. Overall, patients receiving ECD transplants had lower allograft survival after seven years than patients receiving transplants from standard criteria donors (SCD; 80% v 88%, P12 h; 1.53 (1.1 to 2.1); P=0.011). Recipients of ECD kidneys with circulating DSA showed a 5.6-fold increased risk of graft loss compared with all other transplant therapies (P<0.001). ECD allograft survival at seven years significantly improved with screening and transplantation in the absence of circulating DSA (P<0.001) and with shorter (<12 h) cold ischaemia time (P=0.030), respectively. This strategy achieved ECD graft survival comparable to that of patients receiving an SCD transplant overall, translating to a 544.6 allograft life years saved during the nine years of study inclusion time.Conclusions Circulating DSA and cold ischaemia time are the main independent determinants of outcome from ECD transplantation. Allocation policies to avoid DSA and reduction of cold ischaemia time to increase efficacy could promote wider implement of ECD transplantation in the context of organ shortage and improve its prognosis

COVID-19 severity in kidney transplant recipients is similar to nontransplant patients with similar comorbidities

International audienceHigher rates of severe COVID-19 have been reported in kidney transplant recipients (KTRs) compared to nontransplant patients. We aimed to determine if poorer outcomes were specifically related to chronic immunosuppression or underlying comorbidities. We used a 1:1 propensity score-matching method to compare survival and severe disease-free survival (defined as death and/or need for intensive care unit [ICU]) incidence in hospitalized KTRs and nontransplant control patients between February 26 and May 22, 2020. Patients were matched for risk factors of severe COVID-19: age, sex, body mass index, diabetes mellitus, preexisting cardiopathy, chronic lung disease, and basal renal function. We included 100 KTRs (median age [interquartile range (IQR)]) 64.7 years (55.3-73.1) in three French transplant centers. After a median follow-up of 13 days (7-30), transfer to ICU was required for 34 patients (34%) and death occurred in 26 patients (26%). Overall, 43 patients (43%) developed a severe disease during a median follow-up of 8.5 days (2-14). Propensity score matching to a large French cohort of 2017 patients hospitalized in 24 centers, revealed that survival was similar between KTRs and matched nontransplant patients with respective 30-day survival of 62.9% and 71% (p = .38) and severe disease-free 30-day survival of 50.6% and 47.5% (p = .91). These findings suggest that severity of COVID-19 in KTRs is related to their associated comorbidities and not to chronic immunosuppression

Dynamic prediction of renal survival among deeply phenotyped kidney transplant recipients using artificial intelligence: an observational, international, multicohort study

International audienceBackground: Kidney allograft failure is a common cause of end-stage renal disease. We aimed to develop a dynamic artificial intelligence approach to enhance risk stratification for kidney transplant recipients by generating continuously refined predictions of survival using updates of clinical data.Methods: In this observational study, we used data from adult recipients of kidney transplants from 18 academic transplant centres in Europe, the USA, and South America, and a cohort of patients from six randomised controlled trials. The development cohort comprised patients from four centres in France, with all other patients included in external validation cohorts. To build deeply phenotyped cohorts of transplant recipients, the following data were collected in the development cohort: clinical, histological, immunological variables, and repeated measurements of estimated glomerular filtration rate (eGFR) and proteinuria (measured using the proteinuria to creatininuria ratio). To develop a dynamic prediction system based on these clinical assessments and repeated measurements, we used a Bayesian joint models-an artificial intelligence approach. The prediction performances of the model were assessed via discrimination, through calculation of the area under the receiver operator curve (AUC), and calibration. This study is registered with ClinicalTrials.gov, NCT04258891.Findings: 13 608 patients were included (3774 in the development cohort and 9834 in the external validation cohorts) and contributed 89 328 patient-years of data, and 416 510 eGFR and proteinuria measurements. Bayesian joint models showed that recipient immunological profile, allograft interstitial fibrosis and tubular atrophy, allograft inflammation, and repeated measurements of eGFR and proteinuria were independent risk factors for allograft survival. The final model showed accurate calibration and very high discrimination in the development cohort (overall dynamic AUC 0·857 [95% CI 0·847-0·866]) with a persistent improvement in AUCs for each new repeated measurement (from 0·780 [0·768-0·794] to 0·926 [0·917-0·932]; p<0·0001). The predictive performance was confirmed in the external validation cohorts from Europe (overall AUC 0·845 [0·837-0·854]), the USA (overall AUC 0·820 [0·808-0·831]), South America (overall AUC 0·868 [0·856-0·880]), and the cohort of patients from randomised controlled trials (overall AUC 0·857 [0·840-0·875]).Interpretation: Because of its dynamic design, this model can be continuously updated and holds value as a bedside tool that could refine the prognostic judgements of clinicians in everyday practice, hence enhancing precision medicine in the transplant setting

Trajectories of glomerular filtration rate and progression to end stage kidney disease after kidney transplantation

Although the gold standard of monitoring kidney transplant function relies on glomerular filtration rate (GFR), little is known about GFR trajectories after transplantation, their determinants, and their association with outcomes. To evaluate these parameters we examined kidney transplant recipients receiving care at 15 academic centers. Patients underwent prospective monitoring of estimated GFR (eGFR) measurements, with assessment of clinical, functional, histological and immunological parameters. Additional validation took place in seven randomized controlled trials that included a total of 14,132 patients with 403,497 eGFR measurements. After a median follow-up of 6.5 years, 1,688 patients developed end-stage kidney disease. Using unsupervised latent class mixed models, we identified eight distinct eGFR trajectories. Multinomial regression models identified seven significant determinants of eGFR trajectories including donor age, eGFR, proteinuria, and several significant histological features: graft scarring, graft interstitial inflammation and tubulitis, microcirculation inflammation, and circulating anti-HLA donor specific antibodies. The eGFR trajectories were associated with progression to end stage kidney disease. These trajectories, their determinants and respective associations with end stage kidney disease were similar across cohorts, as well as in diverse clinical scenarios, therapeutic eras and in the seven randomized control trials. Thus, our results provide the basis for a trajectory-based assessment of kidney transplant patients for risk stratification and monitoring