Differences in heart rate variability between young and elderly normal men during graded head up tilt.
An autoregressive spectral analysis of heart rate variability (HRV) was used to analyze the differences in autonomic functions during graded head up tilt (HUT) between young and elderly men. After recording at the 0 degree position, the table was rotated to an upright position. The incline of the table was increased progressively to 15 degrees, 30 degrees and 60 degrees. The data obtained from seven young subjects (mean age of 20.0 years) and nine elderly subjects (mean age of 63.3 years) were analyzed. The high frequency components expressed by normalized units (HFnu) were used as the parasympathetic indicators, and HFnu decreased with tilt angle in both age groups. These results suggested that parasympathetic withdrawal have an important role in adaptation to an upright posture in both age groups. However, mean HF amplitude at the 0 degree position in elderly men was not significantly different from that of young men at 60 degrees tilt. A significant interaction effect (age group x tilt angle) was found for mean HF amplitude. The increase of the low frequency components expressed by normalized units (LFnu) and the LF-to-HF ratio in elderly subjects from 0 degree to 15 degrees seemed to be larger than that in young subjects. Sympathetic activities may be sensitive to lower levels of orthostatic stress in the elderly, and the elderly workers are easily affected by a change in workload. Therefore, keeping the workload lower and constant may be recommended to avoid excessive sympathetic activation among the elderly. (+info)
International standards on mental work-load--the ISO 10,075 series.
After a short review of the history and an introduction into the background of standardization in the field of mental work-load an overview over the ISO 10,075 series of standards on ergonomic principles related to mental work-load is given. The review also presents relationships of these standards with some other ergonomic standards and some of the problems associated with standardization in the field of mental work-load. The stress-strain model, the concepts and the terminology used in ISO 10,075 are presented in the overview, together with the basic ideas and the frame of reference of the design guidelines provided by ISO 10,075-2. An outline of the state of discussion and possible developments of a working draft for ISO 10,075-3 on diagnostic methods concludes the presentation of the international standards on mental work-load. (+info)
Measurement of fatigue in industries.
Fatigue of workers is a complex phenomenon resulting from various factors in technically innovated modern industries, and it appears as a feeling of exhaustion, lowering of physiological functions, breakdown of autonomic nervous balance, and decrease in work efficiency. On the other hand industrial fatigue is caused by excessive workload, remarkable alteration in working posture and diurnal and nocturnal rhythms in daily life. Working modes in modern industries have changed from work with the whole body into that with the hands, arms, legs and/or eyes which are parts of the body, and from physical work to mental work. Visual display terminal (VDT) work is one of the most characteristic jobs in the various kinds of workplaces. A large number of fatigue tests have already been adopted, but it is still hard to draw a generalized conclusion as to the method of selecting the most appropriate test battery for a given work load. As apparatus for fatigue measurement of VDT work we have developed VRT (Visual Reaction Test) and the Portable Fatigue Meter. Furthermore, we have presented immune parameters of peripheral blood and splenic T cells for physical fatigue. (+info)
Occupational stress in human computer interaction.
There have been a variety of research approaches that have examined the stress issues related to human computer interaction including laboratory studies, cross-sectional surveys, longitudinal case studies and intervention studies. A critical review of these studies indicates that there are important physiological, biochemical, somatic and psychological indicators of stress that are related to work activities where human computer interaction occurs. Many of the stressors of human computer interaction at work are similar to those stressors that have historically been observed in other automated jobs. These include high workload, high work pressure, diminished job control, inadequate employee training to use new technology, monotonous tasks, por supervisory relations, and fear for job security. New stressors have emerged that can be tied primarily to human computer interaction. These include technology breakdowns, technology slowdowns, and electronic performance monitoring. The effects of the stress of human computer interaction in the workplace are increased physiological arousal; somatic complaints, especially of the musculoskeletal system; mood disturbances, particularly anxiety, fear and anger; and diminished quality of working life, such as reduced job satisfaction. Interventions to reduce the stress of computer technology have included improved technology implementation approaches and increased employee participation in implementation. Recommendations for ways to reduce the stress of human computer interaction at work are presented. These include proper ergonomic conditions, increased organizational support, improved job content, proper workload to decrease work pressure, and enhanced opportunities for social support. A model approach to the design of human computer interaction at work that focuses on the system "balance" is proposed. (+info)
Ergonomic strategies for improving working conditions in some developing countries in Asia.
Ergonomic action is growing in Asia in response to increasing local needs. Recent studies in some developing countries in Asia commonly developed and applied widely-applicable measures for assessing local needs in field conditions including small enterprises and agriculture. For this purpose, carefully examining the actual workplace conditions of the local people was essential. Consequently, a number of field studies could contributed to improving the working conditions of the local people in materials handling, workstation design, work organization and work environment by using available local resources. Building on local capacity and practice, action-oriented ergonomics training has also been developing and spreading into many workplaces. Various non-expert human resources including local government units, trade unions, industrial associations and the agricultural sectors have been mobilized to act as participatory trainers in the action-oriented ergonomic training programmes. Training tools such as action checklists, good local examples and group work dynamics have been developed and applied to such training activities. Learning from local achievements and focusing on locally available resources, ergonomists have facilitated these local action processes by developing action-oriented training tools and training local trainers. It was confirmed that a number of ergonomic improvements could be formulated by the self-help initiative of the local people when participatory action tools and training were provided. Developing flexible and dynamic ergonomic research and training methods to meet the diversifying needs of the local people will continuously be important. Ergonomists' efforts to cover the wider population and workplaces need to be strengthened and accelerated. (+info)
Occupational health psychology: an emerging discipline.
There is growing concern that rapidly changing patterns of work organization and employment pose risk for occupational illness and injury. In the present article, we assert that these changes create new needs and opportunities for research and practice by psychologists in the area of work organization and health. We begin with an historical overview of the contribution of psychologists to the occupational safety and health field, and to the study of work organization and health. We then describe new initiatives by the American Psychological Association and national health organizations in the United States and Europe to frame a new field of study--called "occupational health psychology"--that focuses on the topic of work organization and health. We conclude with a discussion of emerging research needs and trends within this field. (+info)
The Conquest Hospital picture archiving and communications system development, 1992 to 1999.
Conquest Hospital was a UK regional development site for a pre-Digital Imaging and Communications in Medicine (DICOM) picture archiving and communication system (PACS). The initial system was installed in mid 1992. Identification has been made of data transfer, ergonomic and single point of failure issues in the original PACS, which was called "iLAN." This has informed respecification of a DICOM/HTML PACS, the first stages of which have been hospital renetworking and installation of new DICOM 3.0 computed radiography/fluorography and computed tomography/magnetic resonance imaging segments. Final PACS elements are at contract stage. Plans are being completed for linkage of PACS to a clinical information system to create a comprehensive electronic patient record system. (+info)
The effects of strapped spectacles on the fit factors of three manufactured brands of full facepiece negative pressure respirators.
A study was conducted to determine the effects of strapped spectacles on the fit factors obtained during quantitative fit testing on three different brands of full facepiece negative pressure respirators. The three brands of respirators were evaluated with and without strapped spectacles worn by the test subjects. A total of 180 quantitative fit testing trials were conducted on ten male test subjects. For each test subject, three quantitative fit testing trials were performed with each brand of respirator with and without the spectacles. The average of the fit testing trials for each subject with each respirator was used for statistical analysis. The results demonstrated that the fit factor values were significantly lower during use of the spectacles (p < 0.05). The estimated percentage of test subjects who failed the American National Standards Institute pass/fail criteria for quantitative fit testing (1000) increased by 15-36% when spectacles were worn. (+info)