An Improved Method for the Geometrical Calibration of Parallelogram-based Parallel Robots

International audienceThis paper presents an improved method for the geometrical calibration of parallel robots for which the structure is based upon some parallelogram mechanisms. Its originality is to identify the complete geometry of the mechanism's parallelograms, and to compensate the positioning error of the TCP (Tool Centre Point), due to the infinitesimal rotation of the traveling plate, induced by the parallelogram geometrical errors. The main difficulties are: (i) to derive the calibration model relative to all geometrical parameters, and (ii) to reuse the identified errors in a control model in order to compensate the positioning errors. In fact, the position relationship taking into account the full geometry of the parallelograms is difficult, not to say impossible, to derive in a close form; therefore a linear approximation of the model is proposed. The formulas necessary to run the method on a Delta robot are given. Then a simple mechanism is used to illustrate the benefits of this method compared to classical ones

124 Peak systolic 2D strain may help to characterize arrhytmogenic right ventricular cardiomyopathy

BackgroundArrythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disease characterized by progressive fibrofatty replacement of the right ventricle (RV). The diagnosis of ARVC remains a challenge for clinicians. We hypothesized that 2D strain imaging helps to differentiate ARVC from normals.Material and Methods20 patients meeting both the Task Force and cardiac MRI criteria for ARVC were compared to 10 age-matched controls. From the apical-4 chamber view, we measured the end-diastolic RV area, the peak systolic S tissue velocity at the tricuspid level. A 2D strain region of interest including the RV free wall and the septum (occasionally diseased in ARVC) was manually traced, from which the averaged peak systolic 2D strain along 6 segments was calculated. Pulmonary systolic pressure as well as the systolic right atrial area were measured as surrogate for RV loading conditions. Overall, patients with ARVC had both larger right atrial and ventricular area (p<0.03 and p<0.02, respectively), compared to controls while pulmonary systolic pressure were similar in both groups (p=0.40). Peak systolic 2D strain was statistically deteriorated in ARCV patients (13±6 vs. 23±4% in normals, p<0.001) so as peak systolic S tissue velocity (8±3 vs. 12±4 in normals, p<0.005). From the ROC analysis, a peak systolic 2D strain of 19.7% had a sensitivity and specificity of 82% and 86% (AUC=90) while the peak systolic tissue velocity of 12 cm/s gave a sensitivity of 83% and a specificity of 71% (AUC=79).ConclusionPeak systolic 2D strain is deteriorated in ARVC patients and may help to characterize arrythmogenic right ventricular cardiomyopathy

Unusual presentation of metastatic adenocarcinoma

<p>Abstract</p> <p>Background</p> <p>The most common tumours of the adrenal gland are adenoma, pheochromocytoma, adrenocortical carcinoma, and metastases. Although the imaging features of these tumours are established, the imaging characteristics of uncommon adrenal masses are less well known. In patients with extradrenal tumour, incidental discovery of an adrenal mass necessitates excluding the possibility of metastatic malignancy.</p> <p>Case presentation</p> <p>A 52 year-old female was diagnosed with oesophageal adenocarcinoma and treated with oesophagectomy and adjuvant chemotherapy. Sixteen months later on staging CT scan a 2 × 2 cm adrenal mass was detected, which increased in size over a period of time to 3 × 3 cm in size. Adrenalectomy was performed and histological examination revealed metastatic adenocarcinoma within an adrenal adenoma.</p> <p>Conclusion</p> <p>The present case highlights the unusual behaviour of an oesophageal adenocarcinoma causing metastasis to an adrenocortical adenoma.</p

Competitiveness and communication for effective inoculation byRhizobium, Bradyrhizobium and vesicular-arbuscular mycorrhiza fungi

After a short summary on the ecology and rhizosphere biology of symbiotic bacteria and vesicular-arbuscular (VA) mycorrhiza fungi and their application as microbial inocula, results on competitiveness and communication are summarized. Stress factors such as high temperature, low soil pH, aluminium concentrations and phytoalexins produced by the host plants were studied withRhizobium leguminosarum bv.phaseoli andRhizobium tropici onPhaseolus beans. Quantitative data for competitiveness were obtained by usinggus + (glucoronidase) labelled strains, which produce blue-coloured nodules. ForPhaseolus-nodulating rhizobia, a group specific DNA probe was also developed, which did not hybridize with more than 20 other common soil and rhizosphere bacteria. Results from several laboratories contributing to knowledge of signal exchange and communication in theRhizobium/Bradyrhizobium legume system are summarized in a new scheme, including also defense reactions at the early stages of legume nodule initiation. Stimulating effects of flavonoids on germination and growth of VA mycorrhiza fungi were also found. A constitutive antifungal compound in pea roots, -isoxazolinonyl-alanine, was characterized

Multi-national survey on the methods, efficacy, and safety on the post-approval clinical use of pulsed field ablation (MANIFEST-PF).

AIMS Pulsed field ablation (PFA) is a novel atrial fibrillation (AF) ablation modality that has demonstrated preferential tissue ablation, including no oesophageal damage, in first-in-human clinical trials. In the MANIFEST-PF survey, we investigated the 'real world' performance of the only approved PFA catheter, including acute effectiveness and safety-in particular, rare oesophageal effects and other unforeseen PFA-related complications. METHODS AND RESULTS This retrospective survey included all 24 clinical centres using the pentaspline PFA catheter after regulatory approval. Institution-level data were obtained on patient characteristics, procedure parameters, acute efficacy, and adverse events. With an average of 73 patients treated per centre (range 7-291), full cohort included 1758 patients: mean age 61.6 years (range 19-92), female 34%, first-time ablation 94%, paroxysmal/persistent AF 58/35%. Most procedures employed deep sedation without intubation (82.1%), and 15.1% were discharged same day. Pulmonary vein isolation (PVI) was successful in 99.9% (range 98.9-100%). Procedure time was 65 min (38-215). There were no oesophageal complications or phrenic nerve injuries persisting past hospital discharge. Major complications (1.6%) were pericardial tamponade (0.97%) and stroke (0.4%); one stroke resulted in death (0.06%). Minor complications (3.9%) were primarily vascular (3.3%), but also included transient phrenic nerve paresis (0.46%), and TIA (0.11%). Rare complications included coronary artery spasm, haemoptysis, and dry cough persistent for 6 weeks (0.06% each). CONCLUSION In a large cohort of unselected patients, PFA was efficacious for PVI, and expressed a safety profile consistent with preferential tissue ablation. However, the frequency of 'generic' catheter complications (tamponade, stroke) underscores the need for improvement

Digitally-enabled, patient-centred care in rhinitis and asthma multimorbidity: The ARIA-MASK-air® approach

MASK-air®, a validated mHealth app (Medical Device regulation Class IIa) has enabled large observational implementation studies in over 58,000 people with allergic rhinitis and/or asthma. It can help to address unmet patient needs in rhinitis and asthma care. MASK-air® is a Good Practice of DG Santé on digitally-enabled, patient-centred care. It is also a candidate Good Practice of OECD (Organisation for Economic Co-operation and Development). MASK-air® data has enabled novel phenotype discovery and characterisation, as well as novel insights into the management of allergic rhinitis. MASK-air® data show that most rhinitis patients (i) are not adherent and do not follow guidelines, (ii) use as-needed treatment, (iii) do not take medication when they are well, (iv) increase their treatment based on symptoms and (v) do not use the recommended treatment. The data also show that control (symptoms, work productivity, educational performance) is not always improved by medications. A combined symptom-medication score (ARIA-EAACI-CSMS) has been validated for clinical practice and trials. The implications of the novel MASK-air® results should lead to change management in rhinitis and asthma

Integrated, multi-scale and multi-objective design of a mobile fruit and vegetable processing unit

En Afrique subsaharienne, les revenus des producteurs agricoles sont faibles et les pertes post-récolte de fruits et légumes sont importantes. C’est le cas du gombo qui est un légume très apprécié des consommateurs en raison de ses propriétés gluantes. Mais la dégradation de ces propriétés pendant le procédé de conservation freine la consommation locale du gombo sous forme stabilisée.Pour répondre à ces problématiques, la société AS FOOD INTERNATIONAL souhaite développer une unité mobile de transformation (UMT) capable de transformer différents types de fruits et légumes (mangue, ananas, gombo) en purées et/ou en jus. Le principal objectif de cette étude est d’optimiser la conception de cette UMT en mettant en œuvre une méthodologie adaptée.Dans un premier temps le travail de recherche s’est concentré sur le gombo pour : (i) identifier comment mesurer ses propriétés rhéologiques et texturales, (ii) rechercher les méthodes de mesure instrumentale les plus adaptées pour prédire la perception sensorielle de la texture gluante et (iii) suivre la dégradation de la texture du gombo pendant la stabilisation thermique. Les résultats montrent que l’indice de consistance K et le filant sont deux mesures instrumentales nécessaires et suffisantes pour caractériser et discriminer les propriétés rhéologiques et texturales de purées de gombo. Une analyse sensorielle a montré que le gluant est « une propriété texturale complexe résultant de la perception subjective et combinée des propriétés élongationnelles et visqueuses de matrices semi-solides ». Pour prédire la perception sensorielle des sauces gombo, il faut combiner la mesure instrumentale de l’indice de consistance K avec celle du filant. Un plan d’expérience a permis d’identifier les paramètres cinétiques permettant de décrire, modéliser et prédire l’évolution de ces deux indicateurs texturaux en fonction du pH et de la température de stabilisation thermique. Ces résultats ont été utilisés pour construire un modèle capable de prédire la qualité texturale finale d’une purée de gombo en fonction du barème, du format de l’emballage et du type d’autoclave.Dans un second temps, un outil d’aide à la décision a été développé et utilisé pour optimiser la conception de l’UMT. Tout d’abord, l’analyse de l’environnement d’utilisation de l’UMT a permis de définir le scénario d’utilisation et les objectifs de conception. Les variables de conception ont été définies en utilisant une approche de conception intégrée de façon à tenir compte des interactions entre les conditions d’exploitation et la structure de l’UMT. Ensuite, l’UMT a été décomposée hiérarchiquement en 3 niveaux fonctionnels. Au niveau de l’opération unitaire, des modèles prédictifs tenaient compte des caractéristiques des équipements possibles. A ce niveau, le modèle prédictif de la qualité finale de la purée de gombo (et des 3 autres produits finis) a été intégré. Au niveau du procédé, un simulateur d’évènements discrets estimait les performances de la ligne de production pour chaque produit fini. Les performances économiques de l’UMT étaient calculées au niveau de l’atelier. Une échelle de temps caractéristique était associée à chaque niveau fonctionnel et des méthodes de couplage adaptées ont permis de gérer les flux d’informations entre ces 3 niveaux. Puis, les préférences du décideur ont été modélisées et un algorithme d’optimisation a été intégré. L’outil d’aide à la décision a enfin été utilisé et amélioré de façon itérative. Pour cela, les résultats générés étaient visualisés et analysés après chaque itération. Cette démarche a permis de comprendre finement le problème de conception et d’obtenir une solution de conception satisfaisante, faisable et cohérente.Ce travail a conduit à formaliser une méthodologie de conception intégrée combinant les méthodes de simulation multi-échelle et les méthodes d'optimisation multi-objectifs existantes. Elle peut être utilisée pour résoudre de nombreux problèmes de conception.In sub-Saharan Africa, farmers' incomes are low and post-harvest losses of fruit and vegetables are high. This is the case for okra, a vegetable highly appreciated by consumers because of its slimy properties. However, the degradation of its rheological and textural properties during the preservation process is a major obstacle to the local consumption of okra in stabilised form.To address these issues, AS FOOD INTERNATIONAL intends to develop a mobile processing unit (MPU) capable of processing different types of fruits and vegetables (mango, pineapple, okra) into purees and/or juices. The main objective of this study is to optimise the design of this MPU by implementing a suitable methodology.In a first stage, the research work focused on okra to: (i) identify how to measure its rheological and textural properties, (ii) search for the instrumental measurement methods which are the most suitable to predict the sensory perception of the slimy texture and (iii) monitor the degradation of the texture of okra during thermal stabilisation. Results show that the consistency index K and the stringiness are two necessary and sufficient instrumental measures to characterise and discriminate the rheological and textural properties of okra purées. Sensory analysis showed that sliminess is "a complex textural property resulting from the subjective and combined perception of elongational and viscous properties of semi-solid matrices". To predict the sensory perception of okra sauces, it is necessary to combine the instrumental measurement of the consistency index K with the one of stringiness. An experimental design was conducted to identify the kinetic parameters for describing, modelling and predicting the evolution of these two textural indicators as a function of pH and stabilisation temperature. These results were used to build a model capable of predicting the final textural quality of an okra puree as a function of sterilisation temperature, packaging format and type of autoclave.In a second step, a decision support tool was developed and used to optimise the design of the MPU. First, the analysis of the environment of the MPU enabled to define the usage scenario and the design objectives. The design variables were defined using an integrated design approach in order to take into account the interactions between the operating conditions and the structure of the MPU. Then, the MPU was hierarchically decomposed into 3 functional levels. At the unit operation level, predictive models took into account the characteristics of the possible equipment. At this level, the model predicting the final quality of okra puree (and of the 3 other final products) was embedded. At the process level, a discrete event simulator estimated the performance of the production line for each final product. The economic performance of the MPU was calculated at the plant level. A characteristic time scale was associated with each functional level and suitable bridging methods were used to manage the information flows between these 3 levels. Then, the preferences of the decision maker were modelled and an optimisation algorithm was implemented. Finally, the decision support tool was used and improved in an iterative way. For this purpose, the generated results were visualised and analysed after each iteration. This approach enabled a detailed understanding of the design problem and the achievement of a design solution that was satisfactory, feasible and consistent.This work led to the formalisation of an integrated design methodology combining existing multi-scale simulation methods and multi-objective optimisation methods. This comprehensive design methodology can be used to solve many design problems