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Biomedical subjects

Chris Baber

Publications and source records attributed to Chris Baber.

8 recordsLinked to original sources
PubMed2006

Assessing the physical loading of wearable computers.

Wearable computers enable workers to interact with computer equipment in situations where previously they were unable. Attaching a computer to the body though has an unknown physical effect. This paper reports a methodology for addressing this, by assessing postural effects and the effect of added weight. Using the example of arm-mounted computers (AMCs), the paper shows that adopting a posture to interact with an AMC generates fatiguing levels of stress and a load of 0.54 kg results in increased level of stress and increased rate of fatigue. The paper shows that, due to poor postures adopted when wearing and interacting with computers and the weight of the device attached to the body, one possible outcome for prolonged exposure is the development of musculoskeletal disorders.

Adult↗
PubMed2005

Cognitive aspects of tool use.

Tool use has traditionally been viewed as primarily a physical activity, with little consideration given to the cognitive aspects that might be involved. In this paper, a new approach to considering tool use in terms of Forms of Engagement is presented and discussed. This approach combines notions of schema from cognitive psychology with the idea of task-specific devices to explain psychomotor aspects of using tools. From the perspective of Forms of Engagement, various aspects of craftwork and skilled tool use are considered.

Biomechanical Phenomena↗
PubMed2005

A tool to assess the comfort of wearable computers.

Wearable computer comfort can be affected by numerous factors, making its assessment based on one value with one scale inappropriate. This paper presents a tool that measures wearable comfort across six dimensions: emotion, attachment, harm, perceived change, movement, and anxiety. The dimensions for these comfort rating scales were specifically developed for wearable equipment assessment by applying multidimensional scaling to a comfort term association matrix developed using the results of groupings of wearable computer comfort terms. Testing the scales on four different types of wearable computer showed that the scales can be used to highlight differences in comfort between different types of technology for different aspects of comfort. An intraclass correlation of .872 suggested that the scales were used with a high level of reliability. A second study showed that modifications made to a wearable computer resulted in improvements in comfort, although they were not significant (p > .05). A potential application for this research is as an aid to designers and researchers for assessing the wearability, in terms of comfort, of wearable computer devices and to determine the effectiveness of any modifications made to the design of a wearable device.

Adolescent↗
PubMed2004

Neck muscle activity and perceived pain and discomfort due to variations of head load and posture.

BACKGROUND: The increasing use of helmet-mounted displays in aviation raises issues of head-supported weight and neck musculoskeletal function, especially during acceleration. OBJECTIVES: This study aimed to quantify musculoskeletal stress as weight was added to the front of the head in different head positions and determine the effectiveness of a counterbalance in reducing stress. METHODS: There were 20 subjects who participated. The study required that the subject move his head every 10 s for 10 min to one of five positions that were assumed to represent those readily adopted in everyday situations: neutral, 30 degrees extended, 30 degrees flexed, 35 degrees left rotated, and 35 degrees right rotated. Of the subjects, 10 repeated the test while wearing a GSMK6 helmet, and when 0.5 kg, 1.0 kg, or 2.0 kg was added to the front of the helmet. The other 10 subjects repeated the test but with counterbalances. During testing, EMG was recorded from the neck extensors and sternocleidomastoid muscle. Pain levels were recorded using the Borg-CR10 scale. RESULTS: Changes in head position from neutral resulted in significant increases of EMG amplitude (mean +/- SD) in the neck extensors of up to 18 +/- 13% (p < 0.05), and due to head load by 46 +/- 33% (p < 0.05) with a frontal load of 2 kg. Sternocleidomastoid EMG showed little change due to increases in load but increased significantly by up to 265 +/- 227% of the neutral position (p < 0.05) when the head was rotated. CONCLUSIONS: The use of head-mounted displays presents the risk of detrimental effects to the musculoskeletal system. Determining the effect of added weight requires a knowledge of working head postures.

Adult↗
PubMed2002

Objective surgical performance evaluation based on haptic feedback.

In order to develop effective virtual reality training systems for surgery there is a need to provide appropriate sensory and performance feedback to the user. This paper aims to demonstrate a method by which performance data can be collected. This is used to investigate the effect of haptic feedback on performance. A PHANTOM desktop device was used in conjunction with a suturing simulation A pair of needle-holders was instrumented with strain gauges and attached to the stylus of the PHANTOM allowing the measurement of force application and time. Suturing performance was evaluated in terms of stitch completion time, peak force application, and the length and straightness of the stitch. The effect of the level of force feedback provided by the simulation and performance over time was considered. The results indicate that the presence of force feedback affected task completion time, peak force application and the straightness of the stitch. Task completion time was shown to increase with the level of force feedback provided. Performance was seen to improve over time in terms of task completion time and the accuracy ofthe stitch. The work has examined how the presence and level of force feedback affects performance of a simple task. The accuracy of haptic feedback is important in the design of surgical simulation systems to ensure effective training transfer. A data collection method by which objective performance evaluation can be made is demonstrated. The method can be applied to training using bench models, simulations and potentially in the operating theatre.

Clinical Competence↗
PubMedDate not supplied

Event Analysis of Systemic Teamwork (EAST): a novel integration of ergonomics methods to analyse C4i activity.

C4i is defined as the management infrastructure needed for the execution of a common goal supported by multiple agents in multiple locations and technology. In order to extract data from complex and diverse C4i scenarios a descriptive methodology called Event Analysis for Systemic Teamwork (EAST) has been developed. With over 90 existing ergonomics methodologies already available, the approach taken was to integrate a hierarchical task analysis, a coordination demand analysis, a communications usage diagram, a social network analysis, and the critical decision method. The outputs of these methods provide two summary representations in the form of an enhanced operation sequence diagram and a propositional network. These offer multiple overlapping perspectives on key descriptive constructs including who the agents are in a scenario, when tasks occur, where agents are located, how agents collaborate and communicate, what information is used, and what knowledge is shared. The application of these methods to live data drawn from the UK rail industry demonstrates how alternative scenarios can be compared on key metrics, how multiple perspectives on the same data can be taken, and what further detailed insights can be extracted. The ultimate aim of EAST is, by applying it across a number of scenarios in different civil and military domains, to provide data to develop generic models of C4i activity and to improve the design of systems aimed at enhancing this management infrastructure.

Communication↗
PubMedDate not supplied

Command and control in emergency services operations: a social network analysis.

There is increasing interest in the use of social network analysis as a tool to study the performance of teams and organizations. In this paper, processes of command and control in the emergency services are explored from the perspective of social network theory. We report a set of network analyses (comprising visualization, a selection of mathematical metrics, and a discussion of procedures) based on the observation of six emergency service incidents: three fire service operations involving the treatment of hazardous chemicals, and three police operations involving immediate response to emergency calls. The findings are discussed in terms of our attempts to categorize the network structures against a set of extant command and control network archetypes and the relationship between those structures; comments on the qualities the networks display are put into the contexts of the incidents reported. We suggest that social network analysis may have a valuable part to play in the general study of command and control.

Efficiency, Organizational↗