Biomedical subjects

Hongwei Hsiao

Publications and source records attributed to Hongwei Hsiao.

4 recordsLinked to original sources

PubMed2003

Sizing and fit of fall-protection harnesses.

Full-body fall-protection harnesses have been a critical work-practice control technology for reducing the number of fall-related injuries and fatalities among construction workers; yet, very little is known about the fit of these harnesses to the population that wears them. This study evaluated the fit and sizing efficacy of a harness system. Seventy-two male and 26 female construction workers participated in the study. Their body size-and-shape information was measured while they were suspended (with a harness) and standing (with and without a harness), using a 3-D full-body laser scanner and traditional anthropometric calipers. Fisher's discriminant analysis results did not point to the need for a change in the current sizing selection scheme by body height and weight for end users. However, an integrated redesign of harness components is needed because 40% of subjects did not pass fit-performance criteria in either the standing or suspended condition. A multivariate accommodation analysis has identified 15 representative body models for the 'standard-size' harness design. These models can serve as a useful population to test harness design until a larger survey of the nation's construction workers can be done. Finally, further developments in 3-D shape quantification methods are recommended to improve the harness design process; the point-to-point anthropometric information currently used seems to be insufficient for harness design.

Accidental Falls↗

PubMed2003

Control and perception of balance at elevated and sloped surfaces.

Understanding roof-work-related risk of falls and developing low-cost, practical engineering controls for reducing this risk remain in high demand in the construction industry. This study investigated the effects of the roof work environment characteristics of surface slope, height, and visual reference on standing balance in construction workers. The 24 participants were tested in a laboratory setting at 4 slopes (0 degrees, 18 degrees, 26 degrees, and 34 degrees), 2 heights (0, 3 m), and 2 visual conditions (with and without visual references). Postural sway characteristics were calculated using center of pressure recordings from a force platform. Workers' perceptions of postural sway and instability were also evaluated. The results indicated that slope and height synergistically increased workers' standing postural instability. Workers recognized the individual destabilizing effects of slope and height but did not recognize the synergistic effect of the two. Visual references significantly reduced the destabilizing effects of height and slope. Actual and potential applications of this research include the use of temporary level work surfaces and proximal vertical reference structures as postural instability control measures during roofing work.

Accidental Falls↗

PubMed2002

Accuracy and precision of two in-shoe pressure measurement systems.

The recent rapid adoption of insole pressure measurement systems for clinical and ergonomic evaluations of human gait has necessitated a comprehensive understanding of the accuracy and precision of such systems. Five bench experiments were performed to examine the Pedar and F-Scan in-shoe pressure measurement systems. The insoles examined were the Pedar Y-sized right insole and the F-scan insole trimmed to the size and shape of a Pedar Y-sized insole. Data were sampled at 50 Hz at different levels of applied pressure, calibration procedure, duration of pressure application, insole age of use and experiment day or week. The system accuracy was determined by the per cent error of measurement, the system precision by the 95% tolerance interval of the per cent error. The results show that system accuracy and precision varied among levels of applied pressure, calibration procedure, duration of pressure application and insole age of use. The Pedar system showed the greatest accuracy and precision when the insole was new and measurements were taken (1) after a system calibration as specified by the manufacturer, (2) in the 50 - 500 kPa pressure range and (3) within a few seconds after pressure was applied. Under this condition, the measurement error was in the range -0.6 to 2.7%, and the magnitude (upper bound minus lower bound) of the 95% tolerance intervals was from 13.5 to 18.7%. Measuring less than 35 kPa with the Pedar system is not recommended. To ensure the accuracy and precision of the F-Scan system, users are recommended to estimate the range of the applied pressure and then choose a similar pressure level for calibration. Under this condition, the measurement error was in the range 1.3 - 5.8% and the magnitude (upper bound minus lower bound) of the 95% tolerance intervals was estimated to be in the range 1.1 - 14.8%. When the calibration pressure was outside this range of applied pressure, the per cent errors were considerably higher, ranging from -26.3 to 33.9%.

Calibration↗

PubMed2002

Anthropometric differences among occupational groups.

The increasing demands for anthropometric information for the design of machinery and personal protective equipment to prevent occupational injuries has necessitated an understanding of the anthropometric differences to be found among occupations. This study identified differences in various body measurements between occupational groups in the USA, as determined in the third National Health and Nutrition Examination Survey. Approximately 16,000 of its 32,900 subjects were associated with an occupational group. The analysis of the data showed that the body size, or body segment measurements, of some occupational groups differ significantly. For example, agricultural workers were shorter by an average of 2.5 cm in height, and had wider wrist breadths, than other workers. Female agricultural and manufacturing workers had larger waist circumferences than those in the 'other occupations' and 'all occupations' categories. Protective service workers (i.e. firefighters, police and guards) were taller and heavier (7 kg heavier for males and over 10 kg heavier for females) than those in all occupations combined. These differences and other deviations as well as some age-and-ethnicity-adjusted results were tabulated for users' reference. Researchers and designers who use anthropometric databases to evaluate human-machine interfaces and personal protective equipment (PPE) must use caution in selecting databases that are adequate for their occupational applications.

Anthropometry↗