Volumetric performance capture from minimal camera viewpoints

We present a convolutional autoencoder that enables high fidelity volumetric reconstructions of human performance to be captured from multi-view video comprising only a small set of camera views. Our method yields similar end-to-end reconstruction error to that of a probabilistic visual hull computed using significantly more (double or more) viewpoints. We use a deep prior implicitly learned by the autoencoder trained over a dataset of view-ablated multi-view video footage of a wide range of subjects and actions. This opens up the possibility of high-end volumetric performance capture in on-set and prosumer scenarios where time or cost prohibit a high witness camera count

Transvenous lead extraction: Experience of the Tandem approach.

BACKGROUND: Transvenous lead extraction (TLE) is important in the management of cardiac implantable electronic devices but carries risk. TLE is most commonly completed from the superior access, often with 'bail-out' support via the femoral approach. Superior and inferior access may be used in tandem, which has been proposed as an advance in safety and efficacy. AIM: To evaluate the safety and efficacy of the Tandem approach. METHOD: The 'Tandem' procedure entailed grasping of the targeted lead in the right atrium to provide countertraction as a rotational dissecting sheath was advanced over the lead from the subclavian access. Consecutive 'Tandem' procedures performed by a single operator between December 2020 - March 2023 in a single large-volume TLE centre were included and compared with the conventional superior approach (control) using 1:1 propensity score matching; patients were statistically matched for demographics. RESULTS: The Tandem in comparison to the conventional approach extracted leads of much greater dwell time (148.9±79 vs 108.6±77 months, p<0.01) in a shorter procedure duration (96±36 vs 127±67 minutes, p<0.01) but requiring more fluoroscopy (16.4±10.9 vs 10.8±14.9 minutes, p<0.01). The Tandem and control groups had similar clinical (100% vs 94.7%, p=0.07) and complete (94.8% vs 92.8%, p=0.42) success, with comparable minor (4% vs 6.7%, p=0.72) and major (0% vs 4%, p=0.25) complications; procedural (0% vs 1.3%, p=1) and 30-day (1.3% vs 4%, p=0.62) mortality were also similar. CONCLUSION: The Tandem procedure is as safe and effective as the conventional TLE. It can be applied to leads of a long dwell time with a potentially shorter procedure duration

Templates for Convex Cone Problems with Applications to Sparse Signal Recovery

This paper develops a general framework for solving a variety of convex cone problems that frequently arise in signal processing, machine learning, statistics, and other fields. The approach works as follows: first, determine a conic formulation of the problem; second, determine its dual; third, apply smoothing; and fourth, solve using an optimal first-order method. A merit of this approach is its flexibility: for example, all compressed sensing problems can be solved via this approach. These include models with objective functionals such as the total-variation norm, ||Wx||_1 where W is arbitrary, or a combination thereof. In addition, the paper also introduces a number of technical contributions such as a novel continuation scheme, a novel approach for controlling the step size, and some new results showing that the smooth and unsmoothed problems are sometimes formally equivalent. Combined with our framework, these lead to novel, stable and computationally efficient algorithms. For instance, our general implementation is competitive with state-of-the-art methods for solving intensively studied problems such as the LASSO. Further, numerical experiments show that one can solve the Dantzig selector problem, for which no efficient large-scale solvers exist, in a few hundred iterations. Finally, the paper is accompanied with a software release. This software is not a single, monolithic solver; rather, it is a suite of programs and routines designed to serve as building blocks for constructing complete algorithms.Comment: The TFOCS software is available at http://tfocs.stanford.edu This version has updated reference

SIZER: A Dataset and Model for Parsing 3D Clothing and Learning Size Sensitive 3D Clothing

While models of 3D clothing learned from real data exist, no method can predict clothing deformation as a function of garment size. In this paper, we introduce SizerNet to predict 3D clothing conditioned on human body shape and garment size parameters, and ParserNet to infer garment meshes and shape under clothing with personal details in a single pass from an input mesh. SizerNet allows to estimate and visualize the dressing effect of a garment in various sizes, and ParserNet allows to edit clothing of an input mesh directly, removing the need for scan segmentation, which is a challenging problem in itself. To learn these models, we introduce the SIZER dataset of clothing size variation which includes $100$ different subjects wearing casual clothing items in various sizes, totaling to approximately 2000 scans. This dataset includes the scans, registrations to the SMPL model, scans segmented in clothing parts, garment category and size labels. Our experiments show better parsing accuracy and size prediction than baseline methods trained on SIZER. The code, model and dataset will be released for research purposes.Comment: European Conference on Computer Vision 202

Comparison of non-laser and laser transvenous lead extraction: a systematic review and meta-analysis.

BACKGROUND: Transvenous lead extraction (TLE) is performed using non-laser and laser techniques with overall high efficacy and safety. Variation in outcomes between the two approaches does exist with limited comparative evidence in the literature. AIM: We sought to compare non-laser and laser TLE in a meta-analysis. METHODS: We searched Medline, Embase, Scopus, ClinicalTrials.gov and CENTRAL databases for TLE studies published between 1991-2021. From the included 68 studies, safety and efficacy data was carefully evaluated and extracted. Aggregated cases of outcomes were used to calculate odds ratio (OR) and pooled rates were synthesised from eligible studies, to compare non-laser and laser techniques. Subgroup comparison of rotational tool and laser extraction was also performed. RESULTS: Non-laser in comparison to laser had lower procedural mortality (pooled rate 0% vs 0.1%, p < 0.01), major complications (pooled rate 0.7% vs 1.7%, p < 0.01) and superior vena cava (SVC) injury (pooled rate 0% vs 0.5%, p < 0.001), with higher complete success (pooled rate 96.5% vs 93.8%, p < 0.01). Non-laser comparatively to laser was more likely to achieve clinical (OR 2.16 [1.77-2.63], p < 0.01) and complete (OR 1.87 [1.69-2.08], p < 0.01) success, with a lower procedural mortality risk (OR 1.6 [1.02-2.5], p < 0.05). In the subgroup analysis, rotational tool compared to laser achieved greater complete success (pooled rate 97.4% vs 95%, p < 0.01) with lower SVC injury (pooled rate 0% vs 0.7%, p < 0.01). CONCLUSION: Non-laser TLE is associated with a better safety and efficacy profile when compared to laser methods. There is a greater risk of SVC injury associated with laser sheath extraction

Outcome of anal symptoms and anorectal function following two obstetric anal sphincter injuries (OASIS)-a nested case-controlled study.

INTRODUCTION AND HYPOTHESIS: Obstetric anal sphincter injury (OASI) is a significant risk factor for developing anal incontinence. It can therefore be hypothesised that recurrent OASI in a subsequent delivery may predispose women to further anal sphincter dysfunction. METHODS: A nested case-controlled study based on data collected prospectively between 2006 and 2019. Women matched for age and ethnicity, with a history of one OASI and no sphincter damage in a subsequent delivery (control) were compared to women sustaining a second OASI. Assessment was carried out using the St Mark's score (SMIS), anorectal manometry and endoanal ultrasound scan (findings quantified using the modified Starck score). RESULTS: Eighty-four women were included and equally distributed between the two groups, who were followed up 12 weeks postnatally. No difference in SMIS scores was found. Maximum resting pressure (MRP, mmHg) and maximum squeeze pressure (MSP, mmHg) were significantly reduced in the study group. Median (IQR) MRP in the study group was 40.0 (31.3-54.0) versus 46.0 (39.3-61.5) in the control group (p = 0.030). Median (IQR) MSP was 73.0 (58.3-93.5) in the study group versus 92.5 (70.5-110.8) (p = 0.006) in the control group. A significant difference (p = 0.002) was found in the modified Starck score between the study group (median 0.0 [IQR 0.0-6.0]) and control group (median 0.0 [IQR 0.0-0.0]). CONCLUSIONS: We have demonstrated that women with recurrent OASI do not have significant anorectal symptoms compared to those with one OASI 12 weeks after delivery, but worse anal sphincter function and integrity. Therefore, on long-term follow-up, symptoms may possibly develop. This information will be useful when counselling women in a subsequent pregnancy

Noise estimation in cardiac x-ray imaging: a machine vision approach

YesWe propose a method to automatically parameterize noise in cardiac x-ray image sequences. The aim was to provide context-sensitive imaging information for use in regulating dose control feedback systems that relates to the experience of human observers. The algorithm locates and measures noise contained in areas of approximately equal signal level. A single noise metric is derived from the dominant noise components based on their magnitude and spatial location in relation to clinically relevant structures. The output of the algorithm was compared to noise and clinical acceptability ratings from 28 observers viewing 40 different cardiac x-ray imaging sequences. Results show good agreement and that the algorithm has the potential to augment existing control strategies to deliver x-ray dose to the patient on an individual basis.This work has been performed in the project PANORAMA, funded by grants 335 from Belgium, Italy, France, the Netherlands, United Kingdom, and the ENIAC Joint Undertaking

Fermi-LAT observations of the exceptional gamma-ray outbursts of 3C 273 in September 2009

We present the light curves and spectral data of two exceptionally luminous gamma-ray outburts observed by the Large Area Telescope (LAT) experiment on board Fermi Gamma-ray Space Telescope from 3C 273 in September 2009. During these flares, having a duration of a few days, the source reached its highest gamma-ray flux ever measured. This allowed us to study in some details their spectral and temporal structures. The rise and decay are asymmetric on timescales of 6 hours, and the spectral index was significantly harder during the flares than during the preceding 11 months. We also found that short, very intense flares put out the same time-integrated energy as long, less intense flares like that observed in August 2009.Comment: Corresponding authors: E. Massaro, [email protected]; G. Tosti, [email protected]. 15 pages, 4 figures, published in The Astrophysical Journal Letters, Volume 714, Issue 1, pp. L73-L78 (2010