39 research outputs found

    Effect of a mixed reality-based intervention on arm, hand, and finger function on chronic stroke

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    [EN] Background: Virtual and mixed reality systems have been suggested to promote motor recovery after stroke. Basing on the existing evidence on motor learning, we have developed a portable and low-cost mixed reality tabletop system that transforms a conventional table in a virtual environment for upper limb rehabilitation. The system allows intensive and customized training of a wide range of arm, hand, and finger movements and enables interaction with tangible objects, while providing audiovisual feedback of the participants' performance in gamified tasks. This study evaluates the clinical effectiveness and the acceptance of an experimental intervention with the system in chronic stroke survivors. Methods: Thirty individuals with stroke were included in a reversal (A-B-A) study. Phase A consisted of 30 sessions of conventional physical therapy. Phase B consisted of 30 training sessions with the experimental system. Both interventions involved flexion and extension of the elbow, wrist, and fingers, and grasping of different objects. Sessions were 45-min long and were administered three to five days a week. The body structures (Modified Ashworth Scale), functions (Motricity Index, Fugl-Meyer Assessment Scale), activities (Manual Function Test, Wolf Motor Function Test, Box and Blocks Test, Nine Hole Peg Test), and participation (Motor Activity Log) were assessed before and after each phase. Acceptance of the system was also assessed after phase B (System Usability Scale, Intrinsic Motivation Inventory). Results: Significant improvement was detected after the intervention with the system in the activity, both in arm function measured by the Wolf Motor Function Test (p < 0.01) and finger dexterity measured by the Box and Blocks Test (p < 0.01) and the Nine Hole Peg Test (p < 0.01); and participation (p < 0.01), which was maintained to the end of the study. The experimental system was reported as highly usable, enjoyable, and motivating. Conclusions: Our results support the clinical effectiveness of mixed reality interventions that satisfy the motor learning principles for upper limb rehabilitation in chronic stroke survivors. This characteristic, together with the low cost of the system, its portability, and its acceptance could promote the integration of these systems in the clinical practice as an alternative to more expensive systems, such as robotic instruments.The authors wish to thank the staff and patients of the Servicio de Neurorrehabilitación y Daño Cerebral de los Hospitales NISA for their involvement in the study. The authors also wish to thank the staff of LabHuman for their support in this project, especially Francisco Toledo and José Roda for their assistance. This study was funded in part by the Project TEREHA (IDI-20110844) and Project NeuroVR (TIN2013-44741-R) of the Ministerio de Economia y Competitividad of Spain, the Project Consolider-C (SEJ2006-14301/PSIC) of the Ministerio de Educacion y Ciencia of Spain, the "CIBER of Physiopathology of Obesity and Nutrition, an initiative of ISCIII", and the Excellence Research Program PROMETEO of the Conselleria de Educacion of Generalitat Valenciana (2008-157).Colomer Font, C.; Llorens Rodríguez, R.; Noé Sebastián, E.; Alcañiz Raya, ML. (2016). Effect of a mixed reality-based intervention on arm, hand, and finger function on chronic stroke. Journal of NeuroEngineering and Rehabilitation. 13:1-10. https://doi.org/10.1186/s12984-016-0153-6S11013Fregni F, Pascual-Leone A. Hand motor recovery after stroke: tuning the orchestra to improve hand motor function. Cogn Behav Neurol. 2006;19(1):21–33.Patten C, Condliffe EG, Dairaghi CA, Lum PS. 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    Feasibility of a walking virtual reality system for rehabilitation: objective and subjective parameters

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    [EN] Background: Even though virtual reality (VR) is increasingly used in rehabilitation, the implementation of walking navigation in VR still poses a technological challenge for current motion tracking systems. Different metaphors simulate locomotion without involving real gait kinematics, which can affect presence, orientation, spatial memory and cognition, and even performance. All these factors can dissuade their use in rehabilitation. We hypothesize that a marker-based head tracking solution would allow walking in VR with high sense of presence and without causing sickness. The objectives of this study were to determine the accuracy, the jitter, and the lag of the tracking system and its elicited sickness and presence in comparison of a CAVE system. Methods: The accuracy and the jitter around the working area at three different heights and the lag of the head tracking system were analyzed. In addition, 47 healthy subjects completed a search task that involved navigation in the walking VR system and in the CAVE system. Navigation was enabled by natural locomotion in the walking VR system and through a specific device in the CAVE system. An HMD was used as display in the walking VR system. After interacting with each system, subjects rated their sickness in a seven-point scale and their presence in the Slater-Usoh-Steed Questionnaire and a modified version of the Presence Questionnaire. Results: Better performance was registered at higher heights, where accuracy was less than 0.6 cm and the jitter was about 6 mm. The lag of the system was 120 ms. Participants reported that both systems caused similar low levels of sickness (about 2.4 over 7). However, ratings showed that the walking VR system elicited higher sense of presence than the CAVE system in both the Slater-Usoh-Steed Questionnaire (17.6 +/- 0.3 vs 14.6 +/- 0.6 over 21, respectively) and the modified Presence Questionnaire (107.4 +/- 2.0 vs 93.5 +/- 3.2 over 147, respectively). Conclusions: The marker-based solution provided accurate, robust, and fast head tracking to allow navigation in the VR system by walking without causing relevant sickness and promoting higher sense of presence than CAVE systems, thus enabling natural walking in full-scale environments, which can enhance the ecological validity of VR-based rehabilitation applications.The authors wish to thank the staff of LabHuman for their support in this project, especially José Miguel Martínez and José Roda for their assistance. This study was funded in part by Ministerio de Economia y Competitividad of Spain (Project NeuroVR, TIN2013-44741-R and Project REACT, TIN2014-61975-EXP), by Ministerio de Educacion y Ciencia of Spain (Project Consolider-C, SEJ2006-14301/PSIC), and by Universitat Politecnica de Valencia (Grant PAID-10-14).Borrego, A.; Latorre Grau, J.; Llorens Rodríguez, R.; Alcañiz Raya, ML.; Noé, E. (2016). Feasibility of a walking virtual reality system for rehabilitation: objective and subjective parameters. Journal of NeuroEngineering and Rehabilitation. 13:1-9. https://doi.org/10.1186/s12984-016-0174-1S1913Lee KM. Presence. Explicated Communication Theory. 2004;14(1):27–50.Riva G. Is presence a technology issue? Some insights from cognitive sciences. Virtual Reality. 2009;13(3):159–69.Banos RM, et al. Immersion and emotion: their impact on the sense of presence. Cyberpsychol Behav. 2004;7(6):734–41.Llorens R, et al. 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    Bridging the gap between benchtop testing and field conditions in flow assurance studies

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    E-Book - ISBN: 978-1-61399-571-6International audienceObjectives/Scope: The goal for any flow assurance study is to capture the thermo-hydraulic conditions in flowlines without having large scale flow facilities that closely represent the field. As such, benchtop testing must as best as possible reproduce the shear and dispersion of the phases encountered in flowlines. With the increasing need of laboratory testing for solid precipitation and production chemicals, coupled with reduced CAPEX and OPEX, it is critically important to have a robust benchtop testing system that give reliable and transferable data that can be used for field applications.Methods, Procedures, Process: While many benchtop tools are widespread (e.g., autoclave cells, rocking cells, cold fingers) and are used extensively by industry, there is still a significant gap in bridging the results from these lab scale devices to field conditions. One of the major concerns with the current testing rigs is the inability to reproduce the shear AND phases dispersion that are present in pipe flow and are a consequence of the multiphase flow conditions. To bridge the gap To bridge the gap between benchtop testing and filed conditions, we demonstrate how an innovative testing rig, called rock-flow cell, can be used to capture flow assurance issues (e.g., hydrate, wax, asphaltene, scale, corrosion, sand transport) under pseudo-flow conditions.Results, Observations, Conclusions: This system is superior to existing testing systems due to its ability to reproduce flow conditions that are typically found in actual production flowlines, such as, stratified flow, stratified wavy flow, and slug flow. In addition, the system is compact and inexpensive to build and operate, unlike flow loop systems, which are currently the only reliable testing rig with proper flow conditions.Novel/Additive Information: The rock-flow cell can be easily used for testing of chemicals (e.g., anti-agglomerants and kinetic inhibitors) for hydrate management, for assessing wax deposition of crude oils, for testing of scale precipitation, and for testing of sand transport; each of these flow assurance issues can be tested separated or combined as desired. Moreover, the rock-flow cell is also a suitable setup for testing of steady-state and transient (shut-in/restart) conditions typically encountered in flow assurance with proper account of liquid loading, water cut, and GOR

    Differences in the endophytic microbiome of olive cultivars infected by xylella fastidiosa across seasons

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    The dynamics of Xylella fastidiosa infections in the context of the endophytic microbiome was studied in field-grown plants of the susceptible and resistant olive cultivars Kalamata and FS17. Whole metagenome shotgun sequencing (WMSS) coupled with 16S/ITS rRNA gene sequencing was carried out on the same trees at two different stages of the infections: In Spring 2017 when plants were almost symptomless and in Autumn 2018 when the trees of the susceptible cultivar clearly showed desiccations. The progression of the infections detected in both cultivars clearly unraveled that Xylella tends to occupy the whole ecological niche and suppresses the diversity of the endophytic microbiome. However, this trend was mitigated in the resistant cultivar FS17, harboring lower population sizes and therefore lower Xylella average abundance ratio over total bacteria, and a higher α-diversity. Host cultivar had a negligible effect on the community composition and no clear associations of a single taxon or microbial consortia with the resistance cultivar were found with both sequencing approaches, suggesting that the mechanisms of resistance likely reside on factors that are independent of the microbiome structure. Overall, Proteobacteria, Actinobacteria, Firmicutes, and Bacteriodetes dominated the bacterial microbiome while Ascomycota and Basidiomycota those of Fungi
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