We describe a novel probabilistic framework for real-time tracking of multiple objects from combined depth-colour imagery. Object shape is represented implicitly using 3D signed distance functions. ...Probabilistic generative models based on these functions are developed to account for the observed RGB-D imagery, and tracking is posed as a maximum a posteriori problem. We present first a method suited to tracking a single rigid 3D object, and then generalise this to multiple objects by combining distance functions into a shape union in the frame of the camera. This second model accounts for similarity and proximity between objects, and leads to robust real-time tracking without recourse to bolt-on or ad-hoc collision detection.
Powerline infrastructure provides the backbone for the electricity supply of industrial, administrative and private sectors. Its maintenance requires regular inspections, that are still largely ...carried out manually. In this work, we propose an automated inspection system instead. We review current inspection processes as a baseline, give an overview of relevant inspection criteria, propose a suitable multi-modal sensor system, and discuss methods to automate the inspection tasks. In our system, we particularly focus on the high-level organization of the sensor data and inspection results to form a Digital Twin of the power line, that allows operators to browse through the recorded data in a meaningful way and review the status of their powerline from the desk.
We present a novel approach to the structure-from-motion problem which combines the search for correspondences and geometric reconstruction, rather than treating these as separate steps. Through the ...combination of the two steps, we achieve an implicit feedback of 3D information to aid the correspondence search, and at the same time we avoid an explicit model for tracking errors. The reconstruction results are therefore optimal in case of, for example, Gaussian noise on image intensities. We also present an efficient online framework for structure-from-motion with our combined approach, thoroughly evaluate the method in experiments and compare the results to state-of-the-art methods.
Volumetric high-intensity focused ultrasound (HIFU) guided by multiplane magnetic resonance (MR) thermometry has been shown to be a safe and efficient method to thermally ablate large tissue volumes. ...However, the induced temperature rise and thermal lesions show significant variability, depending on exposure parameters, such as power and timing, as well as unknown tissue parameters. In this study, a simple and robust feedback-control method that relies on rapid MR thermometry to control the HIFU exposure during heating is introduced. The binary feedback algorithm adjusts the durations of the concentric ablation circles within the target volume to reach an optimal temperature. The efficacy of the binary feedback control was evaluated by performing 90 ablations in vivo and comparing the results with simulations. Feedback control of the sonications improved the reproducibility of the induced lesion size. The standard deviation of the diameter was reduced by factors of 1.9, 7.2, 5.0, and 3.4 for 4-, 8-, 12-, and 16-mm lesions, respectively. Energy efficiency was also improved, as the binary feedback method required less energy to create the desired lesion. These results show that binary feedback improves the quality of volumetric ablation by consistently producing thermal lesions of expected size while reducing the required energy as well.
Until now, absolute uterine factor infertility has been the major untreatable form of female infertility. Uterus transplantation has recently proven to be the first successful treatment for absolute ...uterine factor infertility, with demonstration of live births. In this study, live donation uterus transplantation was performed in nine women. In total, 163 cervical biopsies (149 protocol, 14 follow‐up) were taken to detect histopathological signs of rejection. Based on experience from animal experiments, we used a three‐grade scoring system to evaluate biopsies systematically. Nine episodes of rejection were diagnosed in five patients: grade 1 in six episodes, grade 2 in two episodes, and grade 3 in one episode. Treatment decisions were based on histopathology, and all rejection episodes were reversed after treatment. The biopsies were reviewed retrospectively, and immunohistochemistry was performed to characterize the inflammatory infiltrates. A borderline category was introduced to avoid overtreatment of patients. Based on our review of all biopsies, we put forward a simple grading system for monitoring of rejection and to guide immunosuppressive treatment in uterus transplantation.
This article presents a preliminary grading system of rejection in uterus transplants using cervical biopsies.
Sensor data fusion from multiple cameras is an important problem for machine vision systems operating in complex, natural environments. We tackle the problem of how information from different sensors ...can be fused in 3D object tracking. We embed an approach called democratic integration into a probabilistic framework and solve the fusion step by hierarchically fusing the information of different sensors and different information sources (cues) derived from each sensor. We compare different fusion architectures and different adaptation schemes. The experiments for 3D object tracking using three calibrated cameras show that adaptive hierarchical fusion improves the tracking robustness and accuracy compared to a flat fusion strategy.
8 patients with plasmocytomas were treated with Endoxan and compared with 5 patients without any considerable treatment. Diagnosis, therapy and prognosis of plasmocytoma are discussed. Particularly ...mentioned are 3 patients with secondary tumours during cytostatic treatment, a plasmocytoma without paraprotein, a tumorous plasmocytoma with double paraproteinemia and a gammopathia with further development into a plasmocytoma 10 years later.
•Reverse flow phenomena so far have only been observed indirectly in experiments.•Long duration PIV records capture time-resolved flow fields of these rare events.•The reverse flow events are ...self-similar and limited to the viscous sublayer.•Their topology matches those observed in direct numerical simulation data.
This study reports on experimentally observed rare near-wall reverse flow events in a fully developed turbulent flat plate boundary layer at zero pressure gradient with Reynolds numbers between Reθ≈2500 and Reθ≈8000 (Reτ≈800–2400). The reverse flow events are captured using high magnification particle image velocimetry sequences with record lengths varying from 50000 to 126000 samples. Time resolved particle image sequences allow singular reverse flow events to be followed over several time steps whereas long records of nearly statistically independent samples provide a variety of single snapshots at a higher spatial resolution. The probability of occurrence lies in the order of 0.012–0.018% which matches predictions from direct numerical simulations (DNS). The typical size of the reverse flow bubble is about 30 wall units in length and 5 wall units in height which agrees well with similar observations made in existing DNS data.
Percutaneous dilatational tracheostomy (PDT) in critically ill patients often involves bronchoscopic optical guidance. However, this procedure is not without disadvantages. Therefore, we aimed to ...study a recently introduced endotracheal tube-mounted camera (VivaSight
-SL tube VST; ETView, Misgav, Israel) for guiding PDT.
This was a randomized controlled trial involving 46 critically ill patients who received PDT using optical guidance with a VST or with bronchoscopy. The primary outcome measure was visualization of the tracheal structures (i.e., identification and monitoring of the thyroid, cricoid, and tracheal cartilage and the posterior wall) rated on 4-point Likert scales. Secondary measures were the quality of ventilation (before puncture and during the tracheostomy procedure rated on 4-point Likert scales) and blood gases sampled at standardized time points.
The mean ratings for visualization (lower values better; values given for per-protocol analysis) were 5.4 (95% CI 4.5-6.3) for the VST group and 4.0 (95% CI 4.0-4.0) for the bronchoscopy group (p < 0.001). Mean ventilation ratings were 2.5 (95% CI 2.1-2.9) for VST and 5.0 (95% CI 4.4-5.7) for bronchoscopy (p < 0.001). Arterial carbon dioxide increased to 5.9 (95% CI 5.4-6.5) kPa in the VST group vs. 8.3 (95% CI 7.2-9.5) kPa in the bronchoscopy group (p < 0.001), and pH decreased to 7.40 (95% CI 7.36-7.43) in the VST group vs. 7.26 (95% CI 7.22-7.30) in the bronchoscopy group (p < 0.001), at the end of the intervention.
Visualization of PDT with the VST is not noninferior to guidance by bronchoscopy. Ventilation is superior with less hypercarbia with the VST. Because visualization is not a prerequisite for PDT, patients requiring stable ventilation with normocarbia may benefit from PDT with the VST.
ClinicalTrials.gov, NCT02861001 . Registered on 13 June 2016.