Realising robust low speed sensorless PMSM control using current derivatives obtained from standard current sensors

This paper describes the implementation of a simple, robust and cost-effective sensorless control technique for PMSM machines. The method uses stator current derivative measurements made in response to certain PWM vectors. In this work the derivatives are created from measurements made with standard hall-effect sensors (at the start and end of switching vectors), meaning that specialist transducers, such as Rogowski Coils, are not required. However, under narrow PWM vectors high frequency (HF) oscillations can disrupt the current and current derivative responses. In previous work, the time that PWM vectors were applied to the machine for was extended to a threshold known as the minimum pulse width (tmin) in order to allow the HF oscillations to decay and a derivative measurement to be obtained. This introduces additional distortion to the motor current. It is shown here that an artificial neural network can be used to estimate derivatives using measurements from a standard current sensor before the HF oscillations have fully decayed, thus permitting a reduction of the minimum pulse width (and associated distortion)

Playful mapping in the digital age:The Playful Mapping Collective

From Mah-Jong, to the introduction of Prussian war-games, through to the emergence of location-based play: maps and play share a long and diverse history. This monograph shows how mapping and playing unfold in the digital age, when the relations between these apparently separate tropes are increasingly woven together. Fluid networks of interaction have encouraged a proliferation of hybrid forms of mapping and playing and a rich plethora of contemporary case-studies, ranging from fieldwork, golf, activism and automotive navigation, to pervasive and desktop-based games evidences this trend. Examining these cases shows how mapping and playing can form productive synergies, but also encourages new ways of being, knowing and shaping our everyday lives. The chapters in this book explore how play can be more than just an object or practice, and instead focus on its potential as a method for understanding maps and spatiality. They show how playing and mapping can be liberating, dangerous, subversive and performative

STEPWISE - STructured lifestyle Education for People WIth SchizophrEnia : a study protocol for a randomised controlled trial

BACKGROUND: People with schizophrenia are two to three times more likely to be overweight than the general population. The UK National Institute of Health and Care Excellence (NICE) recommends an annual physical health review with signposting to, or provision of, a lifestyle programme to address weight concerns and obesity. The purpose of this randomised controlled trial is to assess whether a group-based structured education programme can help people with schizophrenia to lose weight. METHODS: Design: a randomised controlled trial of a group-based structured education programme. SETTING: 10 UK community mental health trusts. PARTICIPANTS: 396 adults with schizophrenia, schizoaffective, or first-episode psychosis who are prescribed antipsychotic medication will be recruited. Participants will be overweight, obese or be concerned about their weight. INTERVENTION: participants will be randomised to either the intervention or treatment as usual (TAU). The intervention arm will receive TAU plus four 2.5-h weekly sessions of theory-based lifestyle structured group education, with maintenance contact every 2 weeks and 'booster' sessions every 3 months. All participants will receive standardised written information about healthy eating, physical activity, alcohol and smoking. OUTCOMES: the primary outcome is weight (kg) change at 1 year post randomisation. Secondary outcomes, which will be assessed at 3 and 12 months, include: the proportion of participants who maintained or reduced their weight; waist circumference; body mass index; objectively measured physical activity (wrist accelerometer); self-reported diet; blood pressure; fasting plasma glucose, lipid profile and HbA1c (baseline and 1 year only); health-related quality of life (EQ-5D-5L and RAND SF-36); (adapted) brief illness perception questionnaire; the Brief Psychiatric Rating Scale; the Client Service Receipt Inventory; medication use; smoking status; adverse events; depression symptoms (Patient Health Questionnaire-9); use of weight-loss programmes; and session feedback (intervention only). Outcome assessors will be blind to trial group allocation. Qualitative interviews with a subsample of facilitators and invention-arm participants will provide data on intervention feasibility and acceptability. Assessment of intervention fidelity will also be performed. DISCUSSION: The STEPWISE trial will provide evidence for the clinical and cost-effectiveness of a tailored intervention, which, if successful, could be implemented rapidly in the NHS. TRIAL REGISTRATION: ISRCTN19447796 , registered on 20 March 2014

Comparative costs and activity from a sample of UK clinical trials units

Background: The costs of medical research are a concern. Clinical Trials Units (CTUs) need to better understand variations in the costs of their activities. Methods: Representatives of ten CTUs and two grant-awarding bodies pooled their experiences in discussions over 1.5 years. Five of the CTUs provided estimates of, and written justification for, costs associated with CTU activities required to implement an identical protocol. The protocol described a 5.5-year, nonpharmacological randomized controlled trial (RCT) conducted at 20 centres. Direct and indirect costs, the number of full time equivalents (FTEs) and the FTEs attracting overheads were compared and qualitative methods (unstructured interviews and thematic analysis) were used to interpret the results. Four members of the group (funding-body representatives or award panel members) reviewed the justification statements for transparency and information content. Separately, 163 activities common to trials were assigned to roles used by nine CTUs; the consistency of role delineation was assessed by Cohen's κ. Results: Median full economic cost of CTU activities was £769,637 (range: £661,112 to £1,383,323). Indirect costs varied considerably, accounting for between 15% and 59% (median 35%) of the full economic cost of the grant. Excluding one CTU, which used external statisticians, the total number of FTEs ranged from 2.0 to 3.0; total FTEs attracting overheads ranged from 0.3 to 2.0. Variation in directly incurred staff costs depended on whether CTUs: supported particular roles from core funding rather than grants; opted not to cost certain activities into the grant; assigned clerical or data management tasks to research or administrative staff; employed extensive on-site monitoring strategies (also the main source of variation in non-staff costs). Funders preferred written justifications of costs that described both FTEs and indicative tasks for funded roles, with itemised non-staff costs. Consistency in role delineation was fair (κ = 0.21-0.40) for statisticians/data managers and poor for other roles (κ < 0.20). Conclusions: Some variation in costs is due to factors outside the control of CTUs such as access to core funding and levels of indirect costs levied by host institutions. Research is needed on strategies to control costs appropriately, especially the implementation of risk-based monitoring strategies

Structured lifestyle education for people with schizophrenia, schizoaffective disorder and first-episode psychosis (STEPWISE): randomised controlled trial

Background Obesity is a major challenge for people with schizophrenia. Aims We assessed whether STEPWISE, a theory-based, group structured lifestyle education programme could support weight reduction in people with schizophrenia. Method In this randomised controlled trial (study registration: ISRCTN19447796), we recruited adults with schizophrenia, schizoaffective disorder or first-episode psychosis from ten mental health organisations in England. Participants were randomly allocated to the STEPWISE intervention or treatment as usual. The 12-month intervention comprised four 2.5 h weekly group sessions, followed by 2-weekly maintenance contact and group sessions at 4, 7 and 10 months. The primary outcome was weight change after 12 months. Key secondary outcomes included diet, physical activity, biomedical measures and patient-related outcome measures. Cost-effectiveness was assessed and a mixed-methods process evaluation was included. Results Between 10 March 2015 and 31 March 2016, we recruited 414 people (intervention 208, usual care 206) with 341 (84.4%) participants completing the trial. At 12 months, weight reduction did not differ between groups (mean difference 0.0 kg, 95% CI-1.6 to 1.7, P = 0.963); physical activity, dietary intake and biochemical measures were unchanged. STEPWISE was well-received by participants and facilitators. The healthcare perspective incremental cost-effectiveness ratio was £246 921 per quality-adjusted life-year gained. Conclusions Participants were successfully recruited and retained, indicating a strong interest in weight interventions; however, the STEPWISE intervention was neither clinically nor cost-effective. Further research is needed to determine how to manage overweight and obesity in people with schizophrenia