A Methodological Approach to User Evaluation and Assessment of a Virtual Environment Hangout

Innovation in virtual reality and motion sensing devices is pushing the development of virtual communication platforms towards completely immersive scenarios, which require full user interaction and create complex sensory experiences. This evolution influences user experiences and creates new paradigms for interaction, leading to an increased importance of user evaluation and assessment on new systems interfaces and usability, to validate platform design and development from the users’ point of view. The REVERIE research project aims to develop a virtual environment service for realistic inter-personal interaction. This paper describes the design challenges faced during the development process of user interfaces and the adopted methodological approach to user evaluation and assessment

Static compliance and driving pressure are associated with ICU mortality in intubated COVID-19 ARDS

Background Pathophysiological features of coronavirus disease 2019-associated acute respiratory distress syndrome (COVID-19 ARDS) were indicated to be somewhat different from those described in nonCOVID-19 ARDS, because of relatively preserved compliance of the respiratory system despite marked hypoxemia. We aim ascertaining whether respiratory system static compliance (Crs), driving pressure (DP), and tidal volume normalized for ideal body weight (VT/kg IBW) at the 1st day of controlled mechanical ventilation are associated with intensive care unit (ICU) mortality in COVID-19 ARDS. Methods Observational multicenter cohort study. All consecutive COVID-19 adult patients admitted to 25 ICUs belonging to the COVID-19 VENETO ICU network (February 28th-April 28th, 2020), who received controlled mechanical ventilation, were screened. Only patients fulfilling ARDS criteria and with complete records of Crs, DP and VT/kg IBW within the 1st day of controlled mechanical ventilation were included. Crs, DP and VT/kg IBW were collected in sedated, paralyzed and supine patients. Results A total of 704 COVID-19 patients were screened and 241 enrolled. Seventy-one patients (29%) died in ICU. The logistic regression analysis showed that: (1) Crs was not linearly associated with ICU mortality (p value for nonlinearity = 0.01), with a greater risk of death for values < 48 ml/cmH(2)O; (2) the association between DP and ICU mortality was linear (p value for nonlinearity = 0.68), and increasing DP from 10 to 14 cmH(2)O caused significant higher odds of in-ICU death (OR 1.45, 95% CI 1.06-1.99); (3) VT/kg IBW was not associated with a significant increase of the risk of death (OR 0.92, 95% CI 0.55-1.52). Multivariable analysis confirmed these findings. Conclusions Crs < 48 ml/cmH(2)O was associated with ICU mortality, while DP was linearly associated with mortality. DP should be kept as low as possible, even in the case of relatively preserved Crs, irrespective of VT/kg IBW, to reduce the risk of death

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

Skeleton parallel programming and parallel objects

Abstract. We describe here the ongoing work aimed at integrating the POP-C++ parallel object programming environment with the ASSIST component based parallel programming environment. Both these programming environments are shortly outlined, first. Then several possibilities of integration are considered. For each one of these integration opportunities, the advantages and synergies that can be possibly achieved are outlined and discussed. Eventually, the current status of integration of the two environments is discussed, along with the expected results and fallouts on the two programming environments.

PAL: Exploiting Java Annotations for Parallelism

We discuss how Java annotations can be used to provide the meta information needed to automatically transform plain Java programs into suitable parallel code that can be run on workstation clusters, networks and grids. Programmers are only required to decorate the methods that will eventually be executed in parallel with standard Java 1.5 annotations. Then these annotations are automatically processed and parallel byte code is derived. When the annotated program is started, it automatically retrieves the information about the executing platform and evaluates the information specified inside the annotations to transform the byte-code into a semantically equivalent multithreaded or multitask version, depending on the target architecture features. The results returned by the annotated methods, when invoked, are futures with a wait-by-necessity semantics. A PAL (Parallel Abstraction Layer) prototype exploiting the annotation based parallelizing approach has been implemented in Java. PAL targets JJPF, an existing, skeleton based, JAVA/JINI programming environment, as Parallel Framework. The experiments made with the prototype are encouraging: the design of parallel applications has been greatly simplified and the performances obtained are the same of an application directly written in JJPF

Network Support for Social 3-D Immersive Tele-Presence with Highly Realistic Natural and Synthetic Avatar Users

The next generation in 3D tele-presence is based on modular systems that combine live captured object based 3D video and synthetically authored 3D graphics content. This paper presents the design, implementation and evaluation of a network solution for multi-party real-time communication of these types of content. This prototype includes a UDP/TCP multi-streaming kernel that includes media synchronization support, packet scheduling, loss resilient real-time transmission and an easy to use blocking and non-blocking API. To compress the live reconstructed 3D data streams that represent the natural user, two categories of 3D mesh codecs were integrated: a highly adaptive real-time geometry driven mesh codec and a fast single rate codec that provides better performance at high resolutions. Subjective tests with 16 subjects indicate that only modest perceptual degradation of the highly realistic 3D natural user is introduced, especially when the users in the virtual world are at a distance. We developed a session management protocol for setting up streams based on the specific 3DTI capabilities allowing device scalability from light (render only) to heavy clients (rendering and 3D Capturing). Additionally, a distributed messaging system via web-sockets and cloud infrastructures based on publish and subscribe was integrated for real-time delivery of avatar and other AI data

PAL: Exploiting Java Annotations for Parallelism

We discuss how Java annotations can be used to provide the meta information needed to automatically transform plain Java programs into suitable parallel code that can be run on workstation clusters, networks and grids. Programmers are only required to decorate the methods that will eventually be executed in parallel with standard Java 1.5 annotations. Then these annotations are automatically processed and parallel byte code is derived. When the annotated program is started, it automatically retrieves the information about the executing platform and evaluates the information specified inside the annotations to transform the byte-code into a semantically equivalent multithreaded or multitask version, depending on the target architecture features. The results returned by the annotated methods, when invoked, are futures with a wait-by-necessity semantics. A PAL (Parallel Abstraction Layer) prototype exploiting the annotation based parallelizing approach has been implemented in Java. PAL targets JJPF, an existing, skeleton based, JAVA/JINI programming environment, as Parallel Framework. The experiments made with the prototype are encouraging: the design of parallel applications has been greatly simplified and the performances obtained are the same of an application directly written in JJPF