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Chris Baber

Publications and source records attributed to Chris Baber.

4 recordsLinked to original sources
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↗