Volume-based Semantic Labeling with Signed Distance Functions

Research works on the two topics of Semantic Segmentation and SLAM (Simultaneous Localization and Mapping) have been following separate tracks. Here, we link them quite tightly by delineating a category label fusion technique that allows for embedding semantic information into the dense map created by a volume-based SLAM algorithm such as KinectFusion. Accordingly, our approach is the first to provide a semantically labeled dense reconstruction of the environment from a stream of RGB-D images. We validate our proposal using a publicly available semantically annotated RGB-D dataset and a) employing ground truth labels, b) corrupting such annotations with synthetic noise, c) deploying a state of the art semantic segmentation algorithm based on Convolutional Neural Networks.Comment: Submitted to PSIVT201

Real-Time RGB-D Camera Pose Estimation in Novel Scenes using a Relocalisation Cascade

Camera pose estimation is an important problem in computer vision. Common techniques either match the current image against keyframes with known poses, directly regress the pose, or establish correspondences between keypoints in the image and points in the scene to estimate the pose. In recent years, regression forests have become a popular alternative to establish such correspondences. They achieve accurate results, but have traditionally needed to be trained offline on the target scene, preventing relocalisation in new environments. Recently, we showed how to circumvent this limitation by adapting a pre-trained forest to a new scene on the fly. The adapted forests achieved relocalisation performance that was on par with that of offline forests, and our approach was able to estimate the camera pose in close to real time. In this paper, we present an extension of this work that achieves significantly better relocalisation performance whilst running fully in real time. To achieve this, we make several changes to the original approach: (i) instead of accepting the camera pose hypothesis without question, we make it possible to score the final few hypotheses using a geometric approach and select the most promising; (ii) we chain several instantiations of our relocaliser together in a cascade, allowing us to try faster but less accurate relocalisation first, only falling back to slower, more accurate relocalisation as necessary; and (iii) we tune the parameters of our cascade to achieve effective overall performance. These changes allow us to significantly improve upon the performance our original state-of-the-art method was able to achieve on the well-known 7-Scenes and Stanford 4 Scenes benchmarks. As additional contributions, we present a way of visualising the internal behaviour of our forests and show how to entirely circumvent the need to pre-train a forest on a generic scene.Comment: Tommaso Cavallari, Stuart Golodetz, Nicholas Lord and Julien Valentin assert joint first authorshi

CORONARY PERFUSION:IMPACT OF FLOW DYNAMICS AND GEOMETRIC DESIGN OF TWO DIFFERENT AORTIC PROSTHESES OF SIMILAR SIZE

BackgroundAortic valve replacement leads to improvement of coronary flow but not to complete normalization. Coronary hypoperfusion contributes to higher left ventricular mass persistence, arrhythmias, congestive heart failure and sudden death. This prospective study compares 2 similarly sized aortic prostheses (mechanical and porcine) regarding coronary flow and hemodynamic performances in patients who underwent surgery for pure aortic stenosis.MethodsSixty patients having undergone aortic valve replacement for pure aortic stenosis with Medtronic Mosaic Ultra bioprosthesis 21 mm (n = 30) or St Jude Regent mechanical valve 19 mm (n = 30) were evaluated preoperatively and 12 months postoperatively comparing the coronary flow and the hemodynamic behavior. Echocardiography and cardiac positron emission tomography were performed at rest and during exercise or adenosine maximal stimulation, respectively.ResultsThe St Jude Regent mechanical valve, compared with the Medtronic Mosaic Ultra bioprosthesis, had reduced coronary flow reserve (2.1 ± 0.3 vs 2.3 ± 0.2; P = .003), less favorable systolic/diastolic time ratio (0.87 ± 0.02 vs 0.78 ± 0.03; P < .001), and higher mean transprosthetic gradient (46 ± 11 vs 38 ± 9; P = .003) during exercise. Multivariate analysis of impaired coronary reserve related indexed effective orifice area less than 0.65 cm/m2 (risk ratio [RR], 1.9; 95% confidence intervals [CI], 1.5-2.8; P < .001), mechanical valve (RR, 2.5; 95% CI, 1.7-3.3; P < .001), and systolic/diastolic time ratio greater than 0.75 (RR, 2.6; 95% CI, 1.8-3.8; P < .001), as well as high transprosthetic gradient (RR, 1.7; 95% CI, 1.3-2.4; P < .001) ) during exercise with coronary reserve less than 2.2.ConclusionsImprovement of coronary flow and reserve was more evident for bioprostheses than for mechanical valves. The bioprostheses demonstrated superior hemodynamics during exercise, which may have some impact on exercise capability during normal daily life

Fluoride Exposure and ADHD: A Systematic Review of Epidemiological Studies

Background and objectives: Attention deficit hyperactivity disorder (ADHD) is a childhood-onset neurodevelopmental disorder characterized by two dimensions: inattentiveness and hyperactivity/impulsivity. ADHD may be the result of complex interactions between genetic, biological and environmental factors possibly including fluoride exposure. Materials and methods: A literature search was performed on 31 March 2023 in the following databases: PubMed, Embase and Web of Science. We defined the following inclusion criteria according to the PECOS statement: a healthy child and adolescent population (P), fluoride exposure of any type (E), comparison with low or null exposure (C), ADHD spectrum disorder (O), and ecological, cross-sectional, case-control and cohort studies (S). Results: We found eight eligible records corresponding to seven different studies investigating the effect of fluoride exposure on children and adolescents. One study had a cohort design and one a case-control one, while five were cross-sectional. Only three studies applied validated questionnaires for the purpose of ADHD diagnosis. As regards exposure assessment, levels of fluoride in urine and tap water were, respectively used in three and two studies, while two used both. Three studies reported a positive association with ADHD risk, all assessing exposure through fluoride levels. By using urinary fluoride, conversely, a positive correlation with inattention, internalizing symptoms, cognitive and psychosomatic problems was found in three studies, but no relation was found in the other one. Conclusions: The present review suggests that early exposure to fluoride may have neurotoxic effects on neurodevelopment affecting behavioral, cognitive and psychosomatic symptoms related to ADHD diagnosis. However, due to the heterogeneity of the studies included, current evidence does not allow to conclusively confirm that fluoride exposure is specifically linked to ADHD development

Continuative statin therapy after percutaneous coronary intervention improves outcome in coronary bypass surgery: A propensity score analysis of 2501 patients

ObjectivesA history of percutaneous coronary intervention increases the risk of death and complications of coronary artery bypass grafting. This retrospective multicenter study evaluated the impact of continuative use of statin on postoperative outcomes when subsequent elective coronary artery bypass grafting is required after percutaneous coronary intervention.MethodsAmong 14,575 patients who underwent isolated first-time coronary artery bypass grafting between January 2000 and December 2010, 2501 who had previous percutaneous coronary intervention with stenting and fulfilled inclusion criteria were enrolled. Continuative statin therapy was used in 1528 patients and not used in 973 patients. Logistic multiple regression and propensity score analyses were used to assess the risk-adjusted impact of statin therapy on in-hospital mortality and major adverse cardiac events. The Cox proportional hazards model was constructed to assess the effect of continuative statin therapy on 24-month outcome.ResultsAt multivariate analysis, age more than 70 years, 3-vessel or 2-vessel plus left main coronary disease, multivessel percutaneous coronary intervention, ejection fraction 0.40 or less, diabetes mellitus, and logistic European System for Cardiac Operative Risk Evaluation 5 or greater were independent predictors of hospital mortality and major adverse cardiac events. After propensity score matching, conditional logistic regression analysis demonstrated that continuative statin therapy before coronary artery bypass grafting reduced the risk for hospital and 2-year mortality (odds ratio [OR], 0.27; 95% confidence interval [CI], 0.12-0. 57; P = .004 and OR, 0.6; 95% CI, 0.36-0.96; P = .04, respectively) and major adverse cardiac events (OR, 0.31; 95% CI, 0.18-0.78; P = .003 and OR, 0.5; 95% CI, 0.34-0.76; P = .006, respectively).ConclusionsLong-term statin treatment after percutaneous coronary intervention improves early and midterm outcome when surgical revascularization will be required

Response of plasma matrix metalloproteinases and tissue inhibitor of metalloproteinases to stent-graft surgery for descending thoracic aortic aneurysms

ObjectiveThe role of matrix metalloproteinases and their tissue endogenous inhibitors has been documented in abdominal aortic aneurysms, but few articles have investigated their role after thoracic aortic aneurysm treatment. Our report investigates matrix metalloproteinases and tissue endogenous inhibitor-1 plasmatic changes in patients who have undergone endovascular aneurysm repair for descending thoracic aortic aneurysms and assesses their clinical significance.MethodsThirty-two patients with thoracic aortic aneurysms who underwent endovascular aneurysm repair were compared with 25 healthy volunteers. Plasma matrix metalloproteinase-3/matrix metalloproteinase-9 and tissue endogenous inhibitor-1 values were determined by an enzyme-linked immunosorbent assay method at a predetermined time interval.ResultsThe preoperative levels of matrix metalloproteinases in the endovascular aneurysm repair group were 3-fold and 2-fold higher than those in the control group (P < .001 and .02, respectively). Matrix metalloproteinase values normalized after endovascular aneurysm repair, whereas patients experiencing endoleaks had higher matrix metalloproteinase values and matrix metalloproteinase-9/tissue endogenous inhibitor-1 ratio compared with the control group (P = .003, < .001, and = .02, respectively, at 1-month follow-up). These values normalized with the resolution of the endoleak.ConclusionsPlasma matrix metalloproteinase values are increased in patients with thoracic aortic aneurysms, along with reduced tissue endogenous inhibitor-1 expression. Successful endovascular aneurysm repair results in values normalization, whereas high levels persist in patients with endoleaks. The enzyme-linked immunosorbent assay test is a simple and reliable technique that is useful to assess the efficacy of endovascular aneurysm repair and to detect endoleaks