Analyzing occupational heat stress using sensor-based monitoring: a wearable approach with environmental ergonomics perspective

Occupational heat stress could impose a greater risk of heat-related morbidities among the exposed users, declining their work productivity and contributing to a financial burden. This necessitate the implementation of adequate preventive measures and control policies to improve the users’ well-being and productive capacity. The emergence of modernistic sensors gives rise to workplace heat stress monitoring at a substantially lower cost than expensive conventional equipment. Present work unveils the productive role of sensor-based safety helmet, which could monitor the environmental variables, heat stress indices, and users’ physiological variables as an indicator of heat strain.

The proposed safety helmet was tested under three different work environments with users’ engaged in specific work activities. Notable variations were perceived among the measured data under respective work conditions and physical activity performed. Higher heat risk exposures were attributable to the outdoor condition compared to indoor work conditions. For wet bulb globe temperature index, strong association (p-value < 0.01) was observed with fighter index of thermal stress (R ²-value = 0.959) followed by Bio Basic Temperature Control Equipment discomfort index (R ²-value = 0.899) and heat index (R ²-value = 0.867).

Results revealed a rise in measured physiological parameters under the heavy workload activity (shoveling task; outdoor location) followed by hacksaw cutting task (indoor location), while least values were associated with light workload activity (drilling task; indoor location). The proposed design intervention could be considered an effective site-specific solution for monitoring heat stress exposures and keeping exposed users well aware of the prevalent thermal work conditions at the individual level.

Open-source projects continue to grow in popularity alongside open-source educational resources, software, and hardware tools. The impact of this increased availability of open-source technologies is that end users are empowered to have greater control over the tools that they work with. This trend extends in the life science laboratory space, where new open-source projects are routinely being published that allow users to build and modify scientific equipment specifically tailored to their needs, often at a reduced cost from equivalent commercial offerings. Recently, we identified a need for a compact orbital shaker that would be usable in temperature and humidity-controlled incubators to support the development and execution of a high-throughput suspension cell-based assay.

Based on the requirements provided by staff biologists, an open-source project known as the DIYbio orbital shaker was identified on Thingiverse, then quickly prototyped and tested. The initial orbital shaker prototype based on the DIYbio design underwent an iterative prototyping and design process that proved to be straightforward due to the open-source nature of the project. The result of these efforts has been the successful initial deployment of ten shakers as of August 2021.

This afforded us the scalability and efficacy needed to complete a large-scale screening campaign in less time and at less cost than if we purchased larger, less adaptable orbital shakers. Lessons learned from prototyping, modifying, validating, deploying and maintaining laboratory devices based on an open-source design in support of a full-scale drug discovery high-throughput screening effort are described within this manuscript.

Oxygen sensor is an important technique in various applications including industrial process control, medical equipment, biological fabrication, etc. The reported optical fiber-based configurations so far, using gas-sensitive coating do not meet the stringent performance targets, such as fast response time and low limit of detection (LOD). Tin-based halide perovskites are sensitive to oxygen with potential use for sensor applications. Here, the halide perovskite-based oxygen optical fiber sensor by combining phenylethylammonium tin iodide (PEA₂ SnI₄ ) and tilted fiber Bragg grating (TFBG) is demonstrated.

The PEA₂ SnI₄ -based oxygen optical fiber sensor is reversible at room temperature with a response time of about 10 s, and the experimental LOD approaches to an extremely low oxygen concentration of about 50 ppm. The as-fabricated oxygen sensor shows a relative response change of 0.6 dB for an oxygen concentration increase from 50 ppm to 5% with good gas selection against NO₂ , CO, CO₂ , H₂ . This work extends the sensor applications of halide perovskites, providing a novel technique for rapid and repeatable oxygen gas detection at a low level.