Incorporating Feedback from Multiple Sensory Modalities Enhances Brain–Machine Interface Control

The brain typically uses a rich supply of feedback from multiple sensory modalities to control movement in healthy individuals. In many individuals, these afferent pathways, as well as their efferent counterparts, are compromised by disease or injury resulting in significant impairments and reduced quality of life. Brain–machine interfaces (BMIs) offer the promise of recovered functionality to these individuals by allowing them to control a device using their thoughts. Most current BMI implementations use visual feedback for closed-loop control; however, it has been suggested that the inclusion of additional feedback modalities may lead to improvements in control. We demonstrate for the first time that kinesthetic feedback can be used together with vision to significantly improve control of a cursor driven by neural activity of the primary motor cortex (MI). Using an exoskeletal robot, the monkey\u27s arm was moved to passively follow a cortically controlled visual cursor, thereby providing the monkey with kinesthetic information about the motion of the cursor. When visual and proprioceptive feedback were congruent, both the time to successfully reach a target decreased and the cursor paths became straighter, compared with incongruent feedback conditions. This enhanced performance was accompanied by a significant increase in the amount of movement-related information contained in the spiking activity of neurons in MI. These findings suggest that BMI control can be significantly improved in paralyzed patients with residual kinesthetic sense and provide the groundwork for augmenting cortically controlled BMIs with multiple forms of natural or surrogate sensory feedback

Improving Brain–Machine Interface Performance by Decoding Intended Future Movements

Objective. A brain–machine interface (BMI) records neural signals in real time from a subject\u27s brain, interprets them as motor commands, and reroutes them to a device such as a robotic arm, so as to restore lost motor function. Our objective here is to improve BMI performance by minimizing the deleterious effects of delay in the BMI control loop. We mitigate the effects of delay by decoding the subject\u27s intended movements a short time lead in the future. Approach. We use the decoded, intended future movements of the subject as the control signal that drives the movement of our BMI. This should allow the user\u27s intended trajectory to be implemented more quickly by the BMI, reducing the amount of delay in the system. In our experiment, a monkey (Macaca mulatta) uses a future prediction BMI to control a simulated arm to hit targets on a screen. Main Results. Results from experiments with BMIs possessing different system delays (100, 200 and 300 ms) show that the monkey can make significantly straighter, faster and smoother movements when the decoder predicts the user\u27s future intent. We also characterize how BMI performance changes as a function of delay, and explore offline how the accuracy of future prediction decoders varies at different time leads. Significance. This study is the first to characterize the effects of control delays in a BMI and to show that decoding the user\u27s future intent can compensate for the negative effect of control delay on BMI performance

“Asymmetric scalloping of the regenerate”: a radiological sign of pseudoaneurysm in distraction osteogenesis

Pseudoaneurysm formation is an uncommon but well-recognised and important complication in limb reconstruction surgery. Postoperative diagnosis is usually clinical or an incidental finding. We present an 11-year-old girl, who underwent two-stage limb lengthening with a circular fixator, for a previously treated pseudoarthrosis of the tibia. During the lengthening plan, a concave defect was noted on one side of the regenerate, which was found to be due to extrinsic compression by a pseudoaneurysm. Normal regenerate formation was seen after selective embolisation of the pseudoaneurysm. This concave appearance on one side of the regenerate has previously been described secondary to a difference in stability on the two sides of the osteotomy, when a monolateral fixator is used, but not due to extrinsic compression by a pseudoaneurysm. The authors propose that this radiographic appearance of “asymmetrical scalloping” on one side of the regenerate may represent a radiological sign of a pseudoaneurysm formation and should provoke investigation for the same

Associations between pre-pregnancy psychosocial risk factors and infant outcomes: a population-based cohort study in England

BACKGROUND: Existing studies evaluating the association between maternal risk factors and specific infant outcomes such as birthweight, injury admissions, and mortality have mostly focused on single risk factors. We aimed to identify routinely recorded psychosocial characteristics of pregnant women most at risk of adverse infant outcomes to inform targeting of early intervention. METHODS: We created a cohort using administrative hospital data (Hospital Episode Statistics) for all births to mothers aged 15-44 years in England, UK, who gave birth on or after April 1, 2010, and who were discharged before or on March 31, 2015. We used generalised linear models to evaluate associations between psychosocial risk factors recorded in hospital records in the 2 years before the 20th week of pregnancy (ie, teenage motherhood, deprivation, pre-pregnancy hospital admissions for mental health or behavioural conditions, and pre-pregnancy hospital admissions for adversity, including drug or alcohol abuse, violence, and self-harm) and infant outcomes (ie, birthweight, unplanned admission for injury, or death from any cause, within 12 months from postnatal discharge). FINDINGS: Of 2 520 501 births initially assessed, 2 137 103 were eligible and were included in the birth outcome analysis. Among the eligible births, 93 279 (4·4%) were births to teenage mothers (age <20 years), 168 186 (7·9%) were births to previous teenage mothers, 51 312 (2·4%) were births to mothers who had a history of hospital admissions for mental health or behavioural conditions, 58 107 (2·7%) were births to mothers who had a history of hospital admissions for adversity, and 580 631 (27·2%) were births to mothers living in areas of high deprivation. 1 377 706 (64·5%) of births were to mothers with none of the above risk factors. Infants born to mothers with any of these risk factors had poorer outcomes than those born to mothers without these risk factors. Those born to mothers with a history of mental health or behavioural conditions were 124 g lighter (95% CI 114-134 g) than those born to mothers without these conditions. For teenage mothers compared with older mothers, 3·6% (95% CI 3·3-3·9%) more infants had an unplanned admission for injury, and there were 10·2 (95% CI 7·5-12·9) more deaths per 10 000 infants. INTERPRETATION: Health-care services should respond proactively to pre-pregnancy psychosocial risk factors. Our study demonstrates a need for effective interventions before, during, and after pregnancy to reduce the downstream burden on health services and prevent long-term adverse effects for children. FUNDING: Wellcome Trust

What works in practice: User and provider perspectives on the acceptability, affordability, implementation, and impact of a family-based intervention for child overweight and obesity delivered at scale

Background: As part of a study considering the impact of a child weight management programme when rolled out at scale following an RCT, this qualitative study focused on acceptability and implementation for providers and for families taking part. Methods: Participants were selected on the basis of a maximum variation sample providing a range of experiences and social contexts. Qualitative interviews were conducted with 29 professionals who commissioned or delivered the programme, and 64 individuals from 23 families in 3 English regions. Topic guides were used as a tool rather than a rule, enabling participants to construct a narrative about their experiences. Transcripts were analysed using framework analysis. Results: Practical problems such as transport, work schedules and competing demands on family time were common barriers to participation. Delivery partners often put considerable efforts into recruiting, retaining and motivating families, which increased uptake but also increased cost. Parents and providers valued skilled delivery staff. Some providers made adaptations to meet local social and cultural needs. Both providers and parents expressed concerns about long term outcomes, and how this was compromised by an obesogenic environment. Concerns about funding together with barriers to uptake and engagement could translate into barriers to commissioning. Where these barriers were not experienced, commissioners were enthusiastic about continuing the programme. Conclusions: Most families felt that they had gained something from the programme, but few felt that it had ‘worked’ for them. The demands on families including time and emotional work were experienced as difficult. For commissioners, an RCT with positive results was an important driver, but family barriers, alongside concerns about recruitment and retention, a desire for local adaptability with qualified motivated staff, and funding changes discouraged some from planning to use the intervention in future

After the RCT: who comes to a family-based intervention for childhood overweight or obesity when it is implemented at scale in the community?

Background: When implemented at scale, the impact on health and health inequalities of public health interventions depends on who receives them in addition to intervention effectiveness. Methods: The MEND 7–13 (Mind, Exercise, Nutrition…Do it!) programme is a family-based weight management intervention for childhood overweight and obesity implemented at scale in the community. We compare the characteristics of children referred to the MEND programme (N=18 289 referred to 1940 programmes) with those of the population eligible for the intervention, and assess what predicts completion of the intervention. Results: Compared to the MEND-eligible population, proportionally more children who started MEND were: obese rather than overweight excluding obese; girls; Asian; from families with a lone parent; living in less favourable socioeconomic circumstances; and living in urban rather than rural or suburban areas. Having started the programme, children were relatively less likely to complete it if they: reported ‘abnormal’ compared to ‘normal’ levels of psychological distress; were boys; were from lone parent families; lived in less favourable socioeconomic circumstances; and had participated in a relatively large MEND programme group; or where managers had run more programmes. Conclusions: The provision and/or uptake of MEND did not appear to compromise and, if anything, promoted participation of those from disadvantaged circumstances and ethnic minority groups. However, this tendency was diminished because programme completion was less likely for those living in less favourable socioeconomic circumstances. Further research should explore how completion rates of this intervention could be improved for particular groups

Energy consumption and capacity utilization of galvanizing furnaces

An explicit equation leading to a method for improving furnace efficiency is presented. This equation is dimensionless and can be applied to furnaces of any size and fuel type for the purposes of comparison. The implications for current furnace design are discussed. Currently the technique most commonly used to reduce energy consumption in galvanizing furnaces is to increase burner turndown. This is shown by the analysis presented here actually to worsen the thermal efficiency of the furnace, particularly at low levels of capacity utilization. Galvanizing furnaces are different to many furnaces used within industry, as a quantity of material (in this case zinc) is kept molten within the furnace at all times, even outside production periods. The dimensionless analysis can, however, be applied to furnaces with the same operational function as a galvanizing furnace, such as some furnaces utilized within the glass industry. © IMechE 2004