Development of inflatable structures at the University of Southampton

Inflatable technology for space applications is under continual development and advances in high strength fibres and rigidizable materials have pushed the limitations of these structures. This has lead to their application in deploying large-aperture antennas, reflectors and solar sails. However, many significant advantages can be achieved by combining inflatable structures with structural stiffeners such as tape springs. These advantages include control of the deployment path of the structure while it is inflating (a past weakness of inflatable structure designs), an increased stiffness of the structure once deployed and a reduction in the required inflation volume. Such structures have been previously constructed at the Jet Propulsion Laboratory focusing on large scale booms. However, due to the high efficiency of these designs they are also appealing to small satellite systems. This article outlines ongoing research work performed at the University of Southampton into the field of small satellite hybrid inflatable structures. Inflatable booms have been constructed and combined with tape spring reinforcements to create simple hybrid structures. These structures have been subjected to bending tests and compared directly to an equivalent inflatable tube without tape spring reinforcement. This enables the stiffness benefits to be determined with respect to the added mass of the tape springs. The paper presents these results, which leads to an initial performance assessment of these structures

Peripartum cardiomyopathy: diagnosis and management

No abstract available

Effectiveness of stroke early supported discharge

Background Implementation of stroke early supported discharge (ESD) services has been recommended in many countries’ clinical guidelines, based on clinical trial evidence. This is the first observational study to investigate the effectiveness of ESD service models operating in real-world conditions, at scale. Methods AND RESULTS Using historical prospective data from the United Kingdom Sentinel Stroke National Audit Programme (January 1, 2016–December 31, 2016), measures of ESD effectiveness were “days to ESD” (number of days from hospital discharge to first ESD contact; n=6222), “rehabilitation intensity” (total number of treatment days/total days with ESD; n=5891), and stroke survivor outcome (modified Rankin scale at ESD discharge; n=6222). ESD service models (derived from Sentinel Stroke National Audit Programme postacute organizational audit data) were categorized with a 17-item score, reflecting adoption of ESD consensus core components (evidence-based criteria). Multilevel modeling analysis was undertaken as patients were clustered within ESD teams across the Midlands, East, and North of England (n=31). A variety of ESD service models had been adopted, as reflected by variability in the ESD consensus score. Controlling for patient characteristics and Sentinel Stroke National Audit Programme hospital score, a 1-unit increase in ESD consensus score was significantly associated with a more responsive ESD service (reduced odds of patient being seen after ≥1 day of 29% [95% CI, 1%–49%] and increased treatment intensity by 2% [95% CI, 0.3%–4%]). There was no association with stroke survivor outcome measured by the modified Rankin Scale. Conclusions This study has shown that adopting defined core components of ESD is associated with providing a more responsive and intensive ESD service. This shows that adherence to evidence-based criteria is likely to result in a more effective ESD service as defined by process measures. REGISTRATION: URL: http://www.isrctn.com/ ; Unique identifier: ISRCTN15568163

Effectiveness of Stroke Early Supported Discharge: Analysis From a National Stroke Registry

BackgroundImplementation of stroke early supported discharge (ESD) services has been recommended in many countries’ clinical guidelines, based on clinical trial evidence. This is the first observational study to investigate the effectiveness of ESD service models operating in real-world conditions, at scale.Methods AND RESULTSUsing historical prospective data from the United Kingdom Sentinel Stroke National Audit Programme (January 1, 2016–December 31, 2016), measures of ESD effectiveness were “days to ESD” (number of days from hospital discharge to first ESD contact; n=6222), “rehabilitation intensity” (total number of treatment days/total days with ESD; n=5891), and stroke survivor outcome (modified Rankin scale at ESD discharge; n=6222). ESD service models (derived from Sentinel Stroke National Audit Programme postacute organizational audit data) were categorized with a 17-item score, reflecting adoption of ESD consensus core components (evidence-based criteria). Multilevel modeling analysis was undertaken as patients were clustered within ESD teams across the Midlands, East, and North of England (n=31). A variety of ESD service models had been adopted, as reflected by variability in the ESD consensus score. Controlling for patient characteristics and Sentinel Stroke National Audit Programme hospital score, a 1-unit increase in ESD consensus score was significantly associated with a more responsive ESD service (reduced odds of patient being seen after ≥1 day of 29% [95% CI, 1%–49%] and increased treatment intensity by 2% [95% CI, 0.3%–4%]). There was no association with stroke survivor outcome measured by the modified Rankin Scale.ConclusionsThis study has shown that adopting defined core components of ESD is associated with providing a more responsive and intensive ESD service. This shows that adherence to evidence-based criteria is likely to result in a more effective ESD service as defined by process measures

How do patients spend their time in stroke rehabilitation units in England? The REVIHR study

Aim: To examine how patients spend their time in stroke rehabilitation units in England.Methods: We recruited 144 patients within a month after stroke from four stroke rehabilitation units and observed their activity type, interactions and location. Each participant was observed for 1 min every 10-minutes, for a total of 20 h, over three consecutive days. Multilevel modelling was performed to assess differences across sites.Results: Across the four sites a total of 12,248 observations were performed. Patients spent on average 37% of the observed time inactive and 60% alone. A health care professional was present for 18% of the observations and patients' most frequent contact was with family members (19%). Patients were mainly physically active in the presence of therapists, but they practiced self-care activities of daily living most frequently in the presence of nursing staff. There were limited opportunities for activity away from the bedside. Significant differences were found between the units, including patients' level of contact with rehabilitation assistants and nursing staff, but not in their time with occupational therapists and physiotherapists.Conclusions: Stroke patients in England spend a large proportion of their day inactive and alone. Opportunities to promote a rehabilitation focused environment may include: a) enhancing the role of rehabilitation assistants, b) supporting nursing staff in maximising opportunities for the practice of activities of daily living and c) involving family members in the rehabilitation process

Late gadolinium enhancement and adverse outcomes in a contemporary cohort of adult survivors of tetralogy of Fallot

Objective: Myocardial fibrosis has been associated with poorer outcomes in tetralogy of Fallot, however only a handful of studies have assessed its significance in the current era. Our aim was to quantify the amount of late gadolinium enhancement in both the LV and RV in a contemporary cohort of adults with surgically repaired tetralogy of Fallot, and assess the relationship with adverse clinical outcomes. Design: Single centre cohort study Setting: National tertiary referral center Patients: One hundred fourteen patients with surgically repaired tetralogy of Fallot with median age 29.5 years (range 17.5-64.2). Prospective follow-up for mean 2.4 years (SD 1.29). Interventions: Cardiovascular magnetic resonance was performed, and late gadolinium enhancement mass was estimated for the LV using the 5-SD remote myocardium method, and for the RV using a segmental scoring system. Cohort characterization was determined through the use of a computerized database. Outcome measures: Survival analysis from time of scan to first adverse event, defined as an episode of atrial arrhythmia, sustained ventricular arrhythmia, hospitalization with heart failure, or implantable cardioverter-defibrillator insertion. Results: Eleven patients experienced an adverse outcome in the follow-up period, although there were no deaths. LV late gadolinium enhancement was associated with adverse outcomes in a univariate model (P = .027). However, when adjusted for age at scan the significant variables included NYHA class (P = .006), peak oxygen uptake (P = .028), number of prior sternotomies (P = .044), and higher indexed RV and LV end diastolic volumes (P = .002 and P < .001), but not RV or LV late gadolinium enhancement. Conclusions: Formal quantification of late gadolinium enhancement is not currently as helpful in ascertaining prognosis compared to other, more easily assessed parameters in a contemporary cohort of tetralogy of Fallot survivors, however assessment particularly of the LV holds promise for the future

A qualitative study exploring how stroke survivors’ expectations and understanding of stroke Early Supported Discharge shaped their experience and engagement with the service

Purpose: To explore how stroke survivors’ expectations and understanding of Early Supported Discharge (ESD) helped them make sense of their experiences, and shaped their engagement with the service. Methods: Data were collected as part of a study of large-scale implementation of stroke ESD: the WISE realist mixed-methods study. Semi-structured interviews were conducted with five purposefully selected stroke survivors from six sites in England implementing stroke ESD (n = 30). Participants were aged 32–88 years (20 males). Interviews were audio recorded, transcribed verbatim and transcripts were analysed using reflexive thematic analysis. Results: Three overarching themes were identified: (1) ESD as a post-stroke recovery tool, (2) desire to recover quickly, (3) psychosocial impact and support. Stroke survivors were uncertain about what to expect when they first entered the service, however, their experience of ESD exceeded their expectations and increased their engagement with the service. Stroke survivors especially valued the goal-oriented approach the team adopted. Rehabilitation at home was perceived as positive and practical, encouraging independence within real-life contexts. Psycho-social support played an important role in the stroke survivors’ rehabilitation. Conclusions: Ensuring stroke survivors are fully informed about ESD and what to expect, optimises engagement with the services, improves experience and could enhance outcomes.IMPLICATIONS FOR REHABILITATION Informing stroke survivors about what to expect from ESD services could optimise engagement and improve their experience. The provision of personalised and target focussed therapy at home improves stroke survivors’ experience and could potentially accelerate recovery. Preparing stroke survivors early for discharge from ESD can reduce anxiety and enhance engagement with the service

Evaluating stroke early supported discharge using cost-consequence analysis

Purpose: To evaluate different stroke Early Supported Discharge (ESD) services in different geographical settings using cost-consequence analysis (CCA), which presents information about costs and outcomes in the form of a balance sheet. ESD is a multidisciplinary service intervention that facilitates discharge from hospital and includes delivery of stroke specialist rehabilitation at home.Materials and methods: Data were collected from six purposively sampled services across the Midlands, East and North of England. All services, rural and urban, provided stroke rehabilitation to patients in their own homes. Cost data included direct and overhead costs of service provision and staff travel. Consequence data included service level adherence to an expert consensus regarding the specification of ESD service provision.Results: We observed that the most rural services had the highest service cost per patient. The main costs associated with running each ESD service were staff costs. In terms of the consequences, there was a positive association between service costs per patient and greater adherence to meeting the evidence-based ESD service specification agreed by an expert panel.Conclusions: This study found that rural services were associated with higher costs per patient, which in turn were associated with greater adherence to the expert consensus regarding ESD service specification. We suggest additional resources and costs are required in order for rural services to meet evidence-based criteria.Study registration: http://www.isrctn.com/ISRCTN1556816

Evolutionary Computation and Explainable AI: A Roadmap to Transparent Intelligent Systems

AI methods are finding an increasing number of applications, but their often black-box nature has raised concerns about accountability and trust. The field of explainable artificial intelligence (XAI) has emerged in response to the need for human understanding of AI models. Evolutionary computation (EC), as a family of powerful optimization and learning tools, has significant potential to contribute to XAI. In this paper, we provide an introduction to XAI and review various techniques in current use for explaining machine learning (ML) models. We then focus on how EC can be used in XAI, and review some XAI approaches which incorporate EC techniques. Additionally, we discuss the application of XAI principles within EC itself, examining how these principles can shed some light on the behavior and outcomes of EC algorithms in general, on the (automatic) configuration of these algorithms, and on the underlying problem landscapes that these algorithms optimize. Finally, we discuss some open challenges in XAI and opportunities for future research in this field using EC. Our aim is to demonstrate that EC is well-suited for addressing current problems in explainability and to encourage further exploration of these methods to contribute to the development of more transparent and trustworthy ML models and EC algorithms.Output Status: Forthcomin

Evolutionary computation and explainable AI: a roadmap to understandable intelligent systems.

Artificial intelligence methods are being increasingly applied across various domains, but their often opaque nature has raised concerns about accountability and trust. In response, the field of explainable AI (XAI) has emerged to address the need for human-understandable AI systems. Evolutionary computation (EC), a family of powerful optimization and learning algorithms, offers significant potential to contribute to XAI, and vice versa. This paper provides an introduction to XAI and reviews current techniques for explaining machine learning models. We then explore how EC can be leveraged in XAI and examine existing XAI approaches that incorporate EC techniques. Furthermore, we discuss the application of XAI principles within EC itself, investigating how these principles can illuminate the behavior and outcomes of EC algorithms, their (automatic) configuration, and the underlying problem landscapes they optimize. Finally, we discuss open challenges in XAI and highlight opportunities for future research at the intersection of XAI and EC. Our goal is to demonstrate EC's suitability for addressing current explainability challenges and to encourage further exploration of these methods, ultimately contributing to the development of more understandable and trustworthy ML models and EC algorithms