Search Results (4)

Conventional thrust vector control nozzles are severely constrained by a single-pivot deflection paradigm, which induces asymmetric shock reflections and adverse boundary layer separation at large angles. Multi-segmented serial configurations offer a promising alternative to overcome these limitations by distributing the total deflection across multiple joint interfaces, thereby achieving large terminal angles and smooth flow-path curvatures. To realize such a configuration, this study draws inspiration from the abdominal bending mechanism of the damselfly Ischnura elegans during mating wheel formation. Real-time video recording and morphological characterizations identified abdominal segments VI and VII as critical for high-amplitude bending under load. Finite element analysis under muscular actuation elucidated the biomechanical synergy, which was rigorously verified through mesh convergence and material property sensitivity checks. Inspired by this biological system, a multi-segmented nozzle configuration incorporating discrete elastic elements and a centralized cable-driven layout was designed and evaluated using multibody dynamics and computational fluid dynamics. The nozzle achieved a continuous 61.20° deflection within 8 s under subsonic exhaust conditions, successfully stabilizing periodic supersonic shock structures and completely suppressing adverse boundary layer separation. These findings turn biological bending into a thrust vectoring method, giving insights for next-generation agile aerospace propulsion systems. Full article

Background/Objectives: Bystander first aid in paediatric choking is crucial. It ought to be universally comprehensible and backed up by evidence-based guidelines. However, there still are inconsistencies in guidelines worldwide. The objective of this research was to assess the knowledge of medical students on paediatric choking rescue manoeuvres and their educational backgrounds in order to evaluate the impact of differences in educational curricula. Methods: Medical students from a total of 12 universities across Canada, Libya, and Poland were surveyed online. The questionnaire assessed the respondents’ experience, training, and knowledge in first aid regarding foreign body airway obstruction in infants and children. Results: Out of 324 responses, 290 were evaluated. Although the students studied in only 3 countries, they represented 37 countries of origin. A total of 7 new reference groups were created based on guideline identification. A comparison of 4 clinical scenario questions revealed that certain training providers communicate recommendations more effectively to medical students, as their guidelines seem to have better knowledge retention. Conclusions: There are important differences in medical student knowledge, possibly due to discrepancies in training programs and guidelines. Variability was found in body position, anti-choking suction devices, blind finger sweeps, and medical follow-ups. More research is needed to standardize training and improve worldwide choking management outcomes. Full article

The management of foreign body airway obstruction has evolved over time from back blows and chest thrusts to abdominal thrusts. However, current guidelines worldwide are based on outdated data, with unclear evidence regarding the effectiveness and safety of these rescue manoeuvres. Concerns persist about the potential of these techniques to cause injury, especially in children; therefore, a critical revision to ensure optimal child safety is necessary. The literature on first aid for paediatric choking was identified through the searching of various databases. Studies were evaluated for their relevance, quality, and currency. The analysis examined guideline consistency with current evidenced-based medicine and identified research gaps. The analysis of the available data was supplemented by adult-based evidence due to the scarcity of paediatric-specific research. First aid guidelines and recommendations for paediatric choking are divergent and generally grounded in low-quality evidence derived primarily from case studies. Studies since 2015 have shown highly diverse methodologies and often lack details on the execution of individual techniques, body positioning or the specific characteristics of study groups, which are crucial when comparing the effectiveness and safety of rescue manoeuvres. Updating evidence-based scientific knowledge for future recommendations is crucial. Full article

Background: Choking is a prevalent source of injury and mortality worldwide. Traditional choking interventions, including abdominal thrusts and back blows, have remained the standard of care for decades despite limited published data. Suction-based airway clearance devices (ACDs) are becoming increasingly popular and there is an urgent need to evaluate their role in choking intervention. The aim of this study was to describe the effectiveness (i.e., resolution of choking symptoms) and safety (i.e., adverse events) of identified airway clearance devices interventions to date. Methods: This retrospective descriptive analysis included any individual who self-identified to manufacturers as having used an ACD as a choking intervention prior to 1 July 2021. Records were included if they contained three clinical variables (patient’s age, type of foreign body, and resolution of choking symptoms). Researchers performed data extraction using a standardized form which included patient, situational, and outcome variables. Results: The analysis included 124 non-invasive (LifeVac©) and 61 minimally invasive (Dechoker©) ACD interventions. Median patient age was 40 (LifeVac©, 2–80) and 73 (Dechoker©, 5–84) with extremes of age being most common [<5 years: LifeVac© 37.1%, Dechoker© 23.0%; 80+ years: 27.4%, 37.7%]. Food was the most frequent foreign body (LifeVac© 84.7%, Dechoker© 91.8%). Abdominal thrusts (LifeVac© 37.9%, Dechoker© 31.1%) and back blows (LifeVac© 39.5%, Dechoker© 41.0%) were often co-interventions. Resolution of choking symptoms occurred following use of the ACD in 123 (LifeVac©) and 60 (Dechoker©) cases. Three adverse events (1.6%) were reported: disconnection of bellows/mask during intervention (LifeVac©), a lip laceration (Dechoker©), and an avulsed tooth (Dechoker©). Conclusion: Initial available data has shown ACDs to be promising in the treatment of choking. However, limitations in data collection methods and quality exist. The second phase of this evaluation will be an industry independent, prospective assessment in order to improve data quality, and inform future choking intervention algorithms. Full article