957 research outputs found

    Using magnetoencephalography to investigate brain activity during high frequency deep brain stimulation in a cluster headache patient

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    PURPOSE: Treatment-resistant cluster headache can be successfully alleviated with deep brain stimulation (DBS) of the posterior hypothalamus [1]. Magnetoencephalography (MEG) is a non-invasive functional imaging technique with both high temporal and high spatial resolution. However, it is not known whether the inherent electromagnetic (EM) noise produced by high frequency DBS is compatible with MEG. MATERIALS AND METHODS: We used MEG to record brain activity in an asymptomatic cluster headache patient with a DBS implanted in the right posterior hypothalamus while he made small movements during periods of no stimulation, 7 Hz stimulation and 180 Hz stimulation. RESULTS: We were able to measure brain activity successfully both during low and high frequency stimulation. Analysis of the MEG recordings showed similar activation in motor areas in during the patient's movements as expected. We also observed similar activations in cortical and subcortical areas that have previously been reported to be associated with pain when the patient's stimulator was turned on or off [2,3]. CONCLUSION: These results show that MEG can be used to measure brain activity regardless of the presence of high frequency deep brain stimulation

    Cost-effectiveness of alternative changes to a national blood collection service.

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    OBJECTIVES: To evaluate the cost-effectiveness of changing opening times, introducing a donor health report and reducing the minimum inter-donation interval for donors attending static centres. BACKGROUND: Evidence is required about the effect of changes to the blood collection service on costs and the frequency of donation. METHODS/MATERIALS: This study estimated the effect of changes to the blood collection service in England on the annual number of whole-blood donations by current donors. We used donors' responses to a stated preference survey, donor registry data on donation frequency and deferral rates from the INTERVAL trial. Costs measured were those anticipated to differ between strategies. We reported the cost per additional unit of blood collected for each strategy versus current practice. Strategies with a cost per additional unit of whole blood less than £30 (an estimate of the current cost of collection) were judged likely to be cost-effective. RESULTS: In static donor centres, extending opening times to evenings and weekends provided an additional unit of whole blood at a cost of £23 and £29, respectively. Introducing a health report cost £130 per additional unit of blood collected. Although the strategy of reducing the minimum inter-donation interval had the lowest cost per additional unit of blood collected (£10), this increased the rate of deferrals due to low haemoglobin (Hb). CONCLUSION: The introduction of a donor health report is unlikely to provide a sufficient increase in donation frequency to justify the additional costs. A more cost-effective change is to extend opening hours for blood collection at static centres

    The effectiveness of artificial intelligence conversational agents in healthcare: a systematic review

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    Background: High demand on healthcare services and the growing capability of artificial intelligence has led to the development of conversational agents designed to support a variety of health-related activities - including behaviour change, treatment support, health monitoring, training, triage, and screening support. Automation of these tasks could free clinicians to focus on more complex work and increase accessibility to healthcare services for the general public. An overarching assessment of the acceptability, usability, and effectiveness of these agents in healthcare is needed to collate the evidence so that future development can target areas for improvement and potential for sustainable adoption. Objective: This systematic review aimed to assess the effectiveness and usability of conversational agents in healthcare and identify the elements that users like and dislike, to inform future research and development of these agents. Methods: PubMed, Medline (Ovid), EMBASE, CINAHL, Web of Science, and ACM Digital Library were systematically searched for articles published since 2008 that evaluated unconstrained natural language processing conversational agents used in healthcare. Endnote (version X9; Clarivate Analytics) reference management software was used for initial screening, then full-text screening was conducted by one reviewer. Data was extracted and risk of bias was assessed by one reviewer and validated by another. Results: A total of 31 studies were selected and included a variety of conversational agents - 14 chatbots (two of which were voice chatbots), 6 embodied conversational agents, 3 each of interactive voice response calls, virtual patients, and speech recognition screening systems, as well as one contextual question answering agent and one voice recognition triage system. Overall, the evidence reported was mostly positive or mixed. Usability and satisfaction performed well (27/30 and 26/31) and positive or mixed effectiveness was found in three quarters of the studies (23/30), but there were several limitations of the agents highlighted in specific qualitative feedback. Conclusions: The studies generally reported positive or mixed evidence for the effectiveness, usability, and satisfactoriness of the conversational agents investigated, but qualitative user perceptions were more mixed. The quality of many of the studies was limited, and improved study design and reporting is necessary to more accurately evaluate the usefulness of the agents in healthcare and identify key areas for improvement. Further research should also analyse the cost-effectiveness, privacy, and security of the agents

    Parton-Hadron Duality in Unpolarised and Polarised Structure Functions

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    We study the phenomenon of parton-hadron duality in both polarised and unpolarised electron proton scattering using the HERMES and the Jefferson Lab data, respectively. In both cases we extend a systematic perturbative QCD based analysis to the integrals of the structure functions in the resonance region. After subtracting target mass corrections and large x resummation effects, we extract the remaining power corrections up to order 1/Q^2. We find a sizeable suppression of these terms with respect to analyses using deep inelastic scattering data. The suppression appears consistently in both polarised and unpolarised data, except for the low Q^2 polarised data, where a large negative higher twist contribution remains. Possible scenarios generating this behavior are discussed.Comment: 17 pages, 9 figure

    On the precision of chiral-dispersive calculations of ππ\pi\pi scattering

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    We calculate the combination 2a0(0)5a0(2)2a_0^{(0)}-5a_0^{(2)} (the Olsson sum rule) and the scattering lengths and effective ranges a1a_1, a2(I)a_2^{(I)} and b1b_1, b2(I)b_2^{(I)} dispersively (with the Froissart--Gribov representation) using, at low energy, the phase shifts for ππ\pi\pi scattering obtained by Colangelo, Gasser and Leutwyler (CGL) from the Roy equations and chiral perturbation theory, plus experiment and Regge behaviour at high energy, or directly, using the CGL parameters for aas and bbs. We find mismatch, both among the CGL phases themselves and with the results obtained from the pion form factor. This reaches the level of several (2 to 5) standard deviations, and is essentially independent of the details of the intermediate energy region (0.82E1.420.82\leq E\leq 1.42 GeV) and, in some cases, of the high energy behaviour assumed. We discuss possible reasons for this mismatch, in particular in connection with an alternate set of phase shifts.Comment: Version to appear in Phys. Rev. D. Graphs and sum rule added. Plain TeX fil

    Zeeman Perturbed 63^{63}Cu Nuclear Quadrupole Resonance Study of the Vortex State of YBa2_2Cu3_3O7δ_{7-\delta}

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    We report a 63^{63}Cu nuclear quadrupole resonance (NQR) study of the vortex state for an aligned polycrystalline sample of a slightly overdoped high-TcT_c superconductor YBa2_2Cu3_3O7δ_{7-\delta} (TcT_{c}\sim92 K) at a low magnetic field of 96 mT along the c axis, near a lower critical field Hc1H_{c1}. We observed the frequency distribution of the nuclear spin-lattice relaxation time 63T1^{63}T_1 in the Zeeman-perturbed 63^{63}Cu NQR spectrum below TcT_c. The characteristic behavior of 1/63T1^{63}T_1, taking the minimum values with respect to temperature and frequency, indicates the significant role of antiferromagnetic spin fluctuations in the Doppler-shifted quasiparticle energy spectrum inside and outside vortex cores.Comment: 4 pages, 4 figure

    What makes you not a Buddhist? : a preliminary mapping of values

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    This study sets out to establish which Buddhist values contrasted with or were shared by adolescents from a non-Buddhist population. A survey of attitude toward a variety of Buddhist values was fielded in a sample of 352 non-Buddhist schoolchildren aged between 13 and 15 in London. Buddhist values where attitudes were least positive concerned the worth of being a monk/nun or meditating, offering candles & incense on the Buddhist shrine, friendship on Sangha Day, avoiding drinking alcohol, seeing the world as empty or impermanent and Nirvana as the ultimate peace. Buddhist values most closely shared by non-Buddhists concerned the Law of Karma, calming the mind, respecting those deserving of respect, subjectivity of happiness, welfare work, looking after parents in old age and compassion to cuddly animals. Further significant differences of attitude toward Buddhism were found in partial correlations with the independent variables of sex, age and religious affiliation. Correlation patterns paralleled those previously described in theistic religions. Findings are applied to spiritual, moral, social and cultural development and for the teaching of religious to pupils of no faith adherence. The study recommends that quantitative psychometrics employed to conceptualize Buddhist values by discriminant validity in this study could be extended usefully to other aspects of the study of Buddhism, particularly in quest of validity in the conceptualization of Buddhist identity within specifically Buddhist populations

    Safety and acceptability of a natural-language AI assistant to deliver clinical follow-up to cataract surgery patients: Proposal for a pragmatic evaluation

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    Background: Due to an ageing population, the demand for many services is exceeding the capacity of the clinical workforce. As a result, staff are facing a crisis of burnout from being pressured to deliver high-volume workloads, driving increasing costs for providers. Artificial intelligence, in the form of conversational agents, presents a possible opportunity to enable efficiencies in the delivery of care. Aims and Objectives: This study aims to evaluate the effectiveness, usability, and acceptability of Dora - an AI-enabled autonomous telemedicine call - for detection of post-operative cataract surgery patients who require further assessment. The study’s objectives are to: 1) establish Dora’s efficacy in comparison to an expert clinician, 2) determine baseline sensitivity and specificity for detection of true complications, 3) evaluate patient acceptability, 4) collect evidence for cost-effectiveness, and 5) capture data to support further development and evaluation. Methods: Based on implementation science, the interdisciplinary study will be a mixed-methods phase one pilot establishing inter-observer reliability of the system, usability, and acceptability. This will be done using using the following scales and frameworks: the system usability scale; assessment of Health Information Technology Interventions in Evidence-Based Medicine Evaluation Framework; the telehealth usability questionnaire (TUQ); the Non-Adoption, Abandonment and Challenges to the Scale-up, Spread and Suitability (NASSS) framework. Results: The results will be included in the final evaluation paper, which we aim to publish in 2022. The study will last eighteen months: seven months of evaluation and intervention refinement, nine months of implementation and follow-up, and two months of post-evaluation analysis and write-up. Conclusions: The project’s key contributions will be evidence on artificial intelligence voice conversational agent effectiveness, and associated usability and acceptability
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