Modeling the relationship between the environment and human experiences

Is low-cost motion capture with artificial intelligence applicable for human working posture risk assessment during manual material handling? A pilot study

BACKGROUND

Assessing working posture risks is important for occupational safety and health. However, low-cost assessment techniques for human motion injuries in the logistics delivery industry have rarely been reported.

OBJECTIVE

To propose a novel approach for posture risk assessment using low-cost motion capture with artificial intelligence.

METHODS

A Kinect was adopted to obtain red-green-blue (RGB) and depth images of the subject with 24 postures, and the human joints were extracted using artificial intelligence. The images were registered to obtain the actual three-dimensional (3D) human joint angle.

RESULTS

The root mean square error (RMSE) significantly decreased. Finally, two common methods for evaluating human working posture injuries-the Rapid Upper Limb Assessment and Ovako Working Posture Analysis System-were investigated.

CONCLUSIONS

The outputs of the proposed method are consistent with those of the commercial ergonomic evaluation software.

Low-grade systemic inflammation and the workplace

BACKGROUND

Psychosocial and physical stressors can elicit the stress response, co-ordinated by interactions between neuroendocrine and inflammatory processes. The central role of the immune system, specifically low-grade systemic inflammation, is sometimes overlooked in work-related stress research.

OBJECTIVE

To review evidence that work-related psychosocial and physical stressors can stimulate a low-grade systemic inflammation which, through interactions with the neurohormonal systems, may impact on the well-being and productivity of workers.

METHODS

Literature searches were performed by databases and by hand. Databases used included Interface - EBSCOhost Research Databases; PsycINFO; Academic Search Complete; Africa-Wide Information; CINAHL; E-Journals; MEDLINE and PsycARTICLES.

RESULTS

Psychosocial stressors, infections, poor indoor air quality, musculoskeletal injuries and chemicals can stimulate a low-grade systemic inflammation that may adversely affect workers' mental and physical health, as well as productivity. The psychological and physical effects caused by infection-induced inflammation are generally referred to as sickness behaviour and those caused by poor indoor air quality as sick building syndrome.

CONCLUSIONS

Stressor-induced low-grade systemic inflammation can be a causal factor in the physical and behavioural symptoms of work-related stress. It is therefore important that those involved with the health of workers be cognisant of inappropriate or chronic low-grade inflammation as a potential health hazard.

Desktop lighting for comfortable use of a computer screen

BACKGROUND:

The contrast between a bright computer screen and a dark ambient environment may influence comfort of the users, especially on their eyes.

OBJECTIVE:

The objective of this research is to identify the optimal desktop lighting for the comfortable use of the computer screen in a dark environment.

METHODS:

An experiment was designed where seven illumination setups were introduced for the users to perform their leisure tasks on a computer screen. Fifteen healthy subjects participated in the experiments. During each session, durations of the eye blinks, fixations and saccades of the user were recorded by an eye tracker. His/her neck and trunk movements were recorded by a motion tracking system as well. The comfort/discomfort questionnaire, localized postural discomfort questionnaire, NASA task load index and computer user questionnaire were used to record the overall comfort/discomfort, the local perceived physical discomfort, the cognitive workload, and general/eye health problems, respectively.

RESULTS:

Subjective and objective measurement results indicated that users felt more comfortable with high intensity warm lights using a computer screen. We also identified that the eye fixation durations, as well as the scores of two questions in the computer user questionnaire, have significant negative correlations with comfort. On the other side, the durations of blinks and the scores of three questions in the computer user questionnaire, were significantly correlated with discomfort.

CONCLUSION:

The warm (3000K) and high intensity (1500 lux) light reduced the visual and cognitive fatigue of the user and therefore improve the comfort of the user during the use of a computer screen.

Introduction to the special issue on comfort: A review of 26 papers from the International Comfort Congress 2019

Various aspects related to comfort are described in this special issue. Some papers are focused on the environment, like smell, temperature, light, acoustics, space and some on an artefact touching the human, like the floor angle, the seat, a bed and light. However, in this special issue also topics like modelling and behavior get more attention.

A multifactorial approach to specify comfortable rail seats

BACKGROUND

A robust rail seat comfort assessment can inform the GB rail industry when procuring new seats and identify areas for comfort improvement in the refurbishment of existing seats, improving the customer experience.

OBJECTIVE

To take a multifactorial approach to measuring comfort and to create a robust seat comfort assessment method for the GB rail industry.

METHODS

Seat comfort assessment scores were developed by identifying seat dimensions (e.g. Seat height, seat width, seat depth), seat pad thickness and hardness requirements, seat accessories and seat attractiveness components. Scores for each seat feature were verified by conducting a fitting trial and asking 7 participants to rank dimensions through a range of adjustment. The combined scoring of features was verified by asking 14 participants to rank seats in three configurations (<minimum comfort; minimum comfort;>minimum comfort). The seat comfort dimensions scores were then validated by ranking seven existing rail seats using the assessment method and comparing the ranks with subjective comfort ranks of 12 participants.

RESULTS

The validation testing resulted in a moderate positive correlation, indicating an alignment between the seat comfort assessment method and subjective comfort scores.

CONCLUSIONS

A multifactorial seat comfort assessment has been shown to be a good indicator of passenger seat comfort.

The effect of aircraft seat pitch on comfort

This study explores the relationship between seat pitch and comfort, and the influencing factors, like space experience and anthropometric measurements. Two hundred ninety-four participants experienced economy class seats in a Boeing 737 with 28-inch, 30-inch, 32-inch and 34-inch seat pitches. Anthropometric measurements of the participants were measured. Participants completed a questionnaire on comfort (10-scale), discomfort (CP-50) and space experience and the results were analysed using SPSS 25. This study showed a significant relationship between seat pitch and comfort as well as discomfort. Additionally, it was found that the mean rank of discomfort of each pitch size for the middle seat was higher than the window and aisle seat, though seat pitch did affect the (dis)comfort more compared with seat location. It was also found that anthropometric sizes significantly affect the (dis)comfort on smaller pitch sizes, and all space experience questions had a correlation to the pitch sizes.