Wireless Software Synchronization of Multiple Distributed Cameras

We present a method for precisely time-synchronizing the capture of image sequences from a collection of smartphone cameras connected over WiFi. Our method is entirely software-based, has only modest hardware requirements, and achieves an accuracy of less than 250 microseconds on unmodified commodity hardware. It does not use image content and synchronizes cameras prior to capture. The algorithm operates in two stages. In the first stage, we designate one device as the leader and synchronize each client device's clock to it by estimating network delay. Once clocks are synchronized, the second stage initiates continuous image streaming, estimates the relative phase of image timestamps between each client and the leader, and shifts the streams into alignment. We quantitatively validate our results on a multi-camera rig imaging a high-precision LED array and qualitatively demonstrate significant improvements to multi-view stereo depth estimation and stitching of dynamic scenes. We release as open source 'libsoftwaresync', an Android implementation of our system, to inspire new types of collective capture applications.Comment: Main: 9 pages, 10 figures. Supplemental: 3 pages, 5 figure

PLC & SCADA based substation automation

lectrical power systems are a technical wonder. Electricity and its accessibility are the\ud greatest engineering achievements of the 20th century. A modern society cannot exist without electricity.\ud Generating stations, transmission lines and distribution systems are the main components of\ud power system. Smaller power systems (called regional grids) are interconnected to form a larger network\ud called national grid, in which power is exchanged between different areas depending upon surplus and\ud deficiency. This requires a knowledge of load flows, which is impossible without meticulous planning and\ud monitoring .Also, the system needs to operate in such a way that the losses and in turn the cost of\ud production are minimum.\ud The major factors that influence the operation of a power system are the changes in load and\ud stability. As is easily understood from the different load curves and load duration curve, the connected\ud load, load varies widely throughout the day. These changes have an impact on the stability of power\ud system. As a severe change in a short span can even lead to loss of synchronism. Stability is also affected\ud by the occurrence of faults, Faults need to be intercepted at an easily stage and corrective measures like\ud isolating the faulty line must be taken.\ud As the power consumption increases globally, unprecedented challenges are being faced,\ud which require modern, sophisticated methods to counter them. This calls for the use of automation in the\ud power system. The Supervisory Control and Data Acquisition (SCADA) and Programmable Logic\ud Controllers (PLC) are an answer to this.\ud SCADA refers to a system that enables on electricity utility to remotely monitor, co-ordinate,\ud control and operate transmission and distribution components, equipment and real-time mode from a\ud remote location with acquisition at date for analysis and planning from one control location.\ud PLC on the other hand is like the brain of the system with the joint operation of the SCADA\ud and the PLC, it is possible to control and operate the power system remotely. Task like\ud Opening of circuit breakers, changing transformer taps and managing the load demand can be carried out\ud efficiently.\ud This type of an automatic network can manage load, maintain quality, detect theft of\ud electricity and tempering of meters. It gives the operator an overall view of the entire network. Also, flow\ud of power can be closely scrutinized and Pilferage points can be located. Human errors leading to tripping\ud can be eliminated. This directly increases the reliability and lowers the operating cost.\ud In short our project is an integration of network monitoring functions with geographical\ud mapping, fault location, load management and intelligent metering

Risk factors for the development of neonatal sepsis in a neonatal intensive care unit of a tertiary care hospital of Nepal.

BACKGROUND: Sepsis is an overwhelming and life-threatening response to bacteria in bloodstream and a major cause of neonatal morbidity and mortality. Understanding the etiology and potential risk factors for neonatal sepsis is urgently required, particularly in low-income countries where burden of infection is high and its epidemiology is poorly understood. METHODS: A prospective observational cohort study was conducted between April 2016 and October 2017 in a level three NICU at a tertiary care hospital in Nepal to determine the bacterial etiology and potential risk factors for neonatal sepsis. RESULTS: Among 142 NICU admitted neonates, 15% (21/142) and 32% (46/142) developed blood culture-positive and -negative neonatal sepsis respectively. Klebsiella pneumoniae (34%, 15/44) and Enterobacter spp. (25%, 11/44) were the most common isolates. The antimicrobial resistance of isolates to ampicillin (100%, 43/43), cefotaxime (74%, 31/42) and ampicillin-sulbactam (55%, 21/38) were the highest. BlaTEM (53%, 18/34) and blaKPC (46%, 13/28) were the commonest ESBL and carbapenemase genes respectively. In univariate logistic regression, the odds of sepsis increased with each additional day of use of invasive procedures such as mechanical ventilation (OR 1.086, 95% CI 1.008-1.170), umbilical artery catheter (OR 1.375, 95% CI 1.049-1.803), intravenous cannula (OR 1.140, 95% CI 1.062-1.225); blood transfusion events (OR 3.084, 95% CI 1.407-6.760); NICU stay (OR 1.109, 95% CI 1.040-1.182) and failure to breast feed (OR 1.130, 95% CI 1.060-1.205). Sepsis odds also increased with leukopenia (OR 1.790, 95% CI 1.04-3.082), increase in C-reactive protein (OR 1.028, 95% CI 1.016-1.040) and decrease in platelets count (OR 0.992, 95% CI 0.989-0.994). In multivariate analysis, increase in IV cannula insertion days (OR 1.147, 95% CI 1.039-1.267) and CRP level (OR 1.028, 95% CI 1.008-1.049) increased the odds of sepsis. CONCLUSIONS: Our study indicated various nosocomial risk factors and underscored the need to improve local infection control measures so as to reduce the existing burden of sepsis. We have highlighted certain sepsis associated laboratory parameters along with identification of antimicrobial resistance genes, which can guide for early and better therapeutic management of sepsis. These findings could be extrapolated to other low-income settings within the region

Types of glaucoma in a university health centre in Al‑Ahsa, Saudi Arabia: a pilot study

Objective: The objective was to assess the profile of different types of glaucoma in a University Health Centre in Al‑Ahsa, Saudi Arabia.Materials and Methods: It is a retrospective study in which the files of the patients at King Faisal University Health Centre were reviewed. The data collected included: Age, sex, race, visual acuity, the slit lamp examination findings, the intraocular pressure (IOP) as the average of 3 readings, the cup‑to‑disc ratio (CDR), the visual field changes, and the details of treatment received.Results: Eighty glaucomatous eyes from 50 patients were included in the study. The mean age was 54.8 ± 12.7 years, and the mean IOP was 19 ± 3.9 mmHg that ranged from 11 to 28 mmHg. The mean CDR mean was 0.48 ± 0.16 that ranged between 0.3 and 0.9. Ninety‑one percent of the visual field defects were arcuate scotomata. Primary open‑angle glaucoma (POAG) (60%) was the most predominant type of glaucoma, followed by primary angle closure glaucoma (ACG) (21.3%), secondary OAG (7.5%), and secondary ACG (6.3%). As for the anti‑glaucoma medications, 88% of the studied patients were on more than one medicine.Conclusion: This pilot study has demonstrated that POAG may be the predominant type of glaucoma in Al‑Ahsa, Kingdom of Saudi Arabia (KSA). Apopulation‑based study with a larger sample size is warranted to confirm the outcome and to provide a baseline data on the prevalence of types of glaucoma in this region of KSA.Keywords: Glaucoma, glaucoma types, prevalence, Saudi Arabi

Cessation and Resumption of Elective Neurointerventional Procedures during the Coronavirus Disease 2019 Pandemic and Future Pandemics

At the time of this writing, the coronavirus disease 2019 pandemic continues to be a global threat, disrupting usual processes, and protocols for delivering health care around the globe. There have been significant regional and national differences in the scope and timing of these disruptions. Many hospitals were forced to temporarily halt elective neurointerventional procedures with the first wave of the pandemic in the spring of 2020, in order to prioritize allocation of resources for acutely ill patients and also to minimize coronavirus disease 2019 transmission risks to non-acute patients, their families, and health care workers. This temporary moratorium on elective neurointerventional procedures is generally credited with helping to flatten the curve and direct scarce resources to more acutely ill patients; however, there have been reports of some delaying seeking medical care when it was in fact urgent, and other reports of patients having elective treatment delayed with the result of morbidity and mortality. Many regions have resumed elective neurointerventional procedures, only to now watch coronavirus disease 2019 positivity rates again climbing as winter of 2020 approaches. A new wave is now forecast which may have larger volumes of hospitalized coronavirus disease 2019 patients than the earlier wave(s) and may also coincide with a wave of patients hospitalized with seasonal influenza. This paper discusses relevant and practical elements of cessation and safe resumption of nonemergent neurointerventional services in the setting of a pandemic

Robust Single-view Cone-beam X-ray Pose Estimation with Neural Tuned Tomography (NeTT) and Masked Neural Radiance Fields (mNeRF)

Many tasks performed in image-guided, mini-invasive, medical procedures can be cast as pose estimation problems, where an X-ray projection is utilized to reach a target in 3D space. Expanding on recent advances in the differentiable rendering of optically reflective materials, we introduce new methods for pose estimation of radiolucent objects using X-ray projections, and we demonstrate the critical role of optimal view synthesis in performing this task. We first develop an algorithm (DiffDRR) that efficiently computes Digitally Reconstructed Radiographs (DRRs) and leverages automatic differentiation within TensorFlow. Pose estimation is performed by iterative gradient descent using a loss function that quantifies the similarity of the DRR synthesized from a randomly initialized pose and the true fluoroscopic image at the target pose. We propose two novel methods for high-fidelity view synthesis, Neural Tuned Tomography (NeTT) and masked Neural Radiance Fields (mNeRF). Both methods rely on classic Cone-Beam Computerized Tomography (CBCT); NeTT directly optimizes the CBCT densities, while the non-zero values of mNeRF are constrained by a 3D mask of the anatomic region segmented from CBCT. We demonstrate that both NeTT and mNeRF distinctly improve pose estimation within our framework. By defining a successful pose estimate to be a 3D angle error of less than 3 deg, we find that NeTT and mNeRF can achieve similar results, both with overall success rates more than 93%. However, the computational cost of NeTT is significantly lower than mNeRF in both training and pose estimation. Furthermore, we show that a NeTT trained for a single subject can generalize to synthesize high-fidelity DRRs and ensure robust pose estimations for all other subjects. Therefore, we suggest that NeTT is an attractive option for robust pose estimation using fluoroscopic projections

The professional and personal impact of the coronavirus pandemic on US neurointerventional practices: a nationwide survey

Background Little is currently known about the effects of the coronavirus (COVID-19) pandemic on neurointerventional (NI) procedural volumes or its toll on physician wellness. Methods A 37-question online survey was designed and distributed to physician members of three NI physician organizations. Results A total of 151 individual survey responses were obtained. Reduced mechanical thrombectomy procedures compared with pre-pandemic were observed with 32% reporting a greater than 50% reduction in thrombectomy volumes. In concert with most (76%) reporting at least a 25% reduction in non-mechanical thrombectomy urgent NI procedures and a nearly unanimous (96%) cessation of non-urgent elective cases, 68% of physicians reported dramatic reductions (\u3e50%) in overall NI procedural volume compared with pre-pandemic. Increased door-to- puncture times were reported by 79%. COVID-19-positive infections occurred in 1% of physician respondents: an additional 8% quarantined for suspected infection. Sixty-six percent of respondents reported increased career stress, 56% increased personal life/family stress, and 35% increased career burnout. Stress was significantly increased in physicians with COVID-positive family members (P\u3c0.05). Conclusions This is the first study designed to understand the effects of the COVID-19 pandemic on NI physician practices, case volumes, compensation, personal/family stresses, and work-related burnout. Future studies examining these factors following the resumption of elective cases and relaxing of social distancing measures will be necessary to better understand these phenomena