Ergonomics
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The development of physiologic monitors has contributed to the decline in morbidity and mortality in patients undergoing anaesthesia. Diverse factors (physiologic, technical, historical and medico-legal) create challenges for monitor alarm designers. Indeed, a growing body of literature suggests that alarms function sub-optimally in supporting the human operator. Despite existing technology that could allow more appropriate design, most anaesthesia alarms still operate on simple, pre-set thresholds. Arguing that more alarms do not necessarily make for safer alarms is difficult in a litigious medico-legal environment and a competitive marketplace. The resultant commitment to the status quo exposes the risks that a lack of an evidence-based theoretical framework for anaesthesia alarm design presents. In this review, two specific theoretical foundations with relevance to anaesthesia alarms are summarised. The potential significance that signal detection theory and cognitive systems engineering could have in improving anaesthesia alarm design is outlined and future research directions are suggested. ⋯ The development of physiologic monitors has increased safety for patients undergoing anaesthesia. Evidence suggests that the full potential of the alarms embedded within those monitors is not being realised. In this review article, the authors propose a theoretical framework that could lead to the development of more ergonomic anaesthesia alarms.
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Comparative Study
A biomechanical and subjective assessment and comparison of three ambulance cot design configurations.
Effects of ambulance cot design features (handle design and leg folding mechanism) were evaluated. Experienced ambulance workers performed tasks simulating loading and unloading a cot to and from an ambulance, and a cot raising task. Muscle activity, ratings of perceived exertion, and performance style were significantly affected by cot condition (p < 0.05). ⋯ Providing handle options and automatic leg folding/unfolding operation can reduce cot operator's effort and physical strain. Practitioner Summary: Paramedics frequently incur musculoskeletal injuries associated with patient-handling tasks. A controlled experiment was conducted to assess effects of ambulance cot design features on physical stress of operators, as seen through muscle activity and operator's perceptions. Differences between cots were found, signalling that intentional design can reduce operator's physical stress.
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To examine the effects of firefighters' self-contained breathing apparatus' (SCBA) weight and its harness design on the physiological and subjective responses, eight male students performed treadmill exercise under four conditions: the 8 kg firefighter protective clothing (PC) (Control), the PC + an 11 kg SCBA with an old harness (Test A), the PC + a 6.4 kg SCBA with an old harness (Test B) and the PC + a 6.4 kg SCBA with a new harness (Test C), at ambient temperatures (T(a)) of 22°C and 32°C. Besides highlighting the fact that a heavy SCBA had a significant effect on the oxygen consumption and metabolic rate, this experiment also found that in a T(a) of 32°C, in particular, the combined effect of 4.7 kg lighter SCBA and new harness design could reduce metabolic rate and improved subjective muscle fatigue and thermal discomfort. ⋯ An effort to alleviate the physiological and subjective burden of firefighters by reducing the weight of SCBA and by using the new harness design has provided satisfactory results in reduced oxygen consumption and in improved subjective responses in a hot air environment.
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Work-related musculoskeletal pain (MSP) risk assessments by trained observers are often used in ergonomic practice; however, the validity may be questionable. We investigated the predictive value of work-site MSP risk estimates in a prospective cohort study of 1745 workers. Trained observers estimated the risk of MSP (neck, shoulder or low-back pain) using a three-point scale (high, moderate and low risk) after observing a video of randomly selected workers representing a task group. ⋯ The results show that observers were able to estimate the risk of shoulder and neck pain, whereas they found it difficult to estimate the risk of low-back pain. Practitioner Summary: Work-related musculoskeletal pain risk assessments by observers are often used in ergonomic practice. We showed that observers were able to estimate shoulder and neck pain risk, but had difficulties to estimate the risk of low-back pain. Therefore, observers' risk estimates might provide a useful method for musculoskeletal pain risk assessments.
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Although adaptive coordination has been highlighted by several studies, research dealing with how adaptive coordination develops is still rare. Thus, the aim of this study was to investigate the development of coordination mechanisms and their task-related adaptation in a longitudinal observation of medical simulation-based training of final year students. We recorded six anaesthesia teams during a sequence of four task scenarios, and each scenario comprised of a routine and a complication phase. After trained observers rated sub-tasks within each scenario for explicit and implicit coordination, statistical analysis revealed a statistically significant effect of previous scenarios on coordination development in the routine phases. While the amount of explicit coordination decreased, implicit coordination increased, revealing adaptive coordination as a skill developed through repeated group interaction. We conclude that anaesthesia training should consider cost- and patient safety-benefits of implicit and explicit coordination and focus on adaptive coordination. ⋯ Group coordination is crucial to anaesthesia team performance. Results of this longitudinal observation of six anaesthesia teams during four medical simulation-based training scenarios document that teams develop adaptive patterns of coordination. This study also demonstrates that adaptive coordination is a trainable skill within crisis resource management training.