Physiological Sensing

This Toolset contains resources for understanding more about how physiological data can be used to explore human performance and cognition in digital manufacturing.

What is Physiological Sensing?

In the context of this project, physiological sensing refers to the use of sensor to capture signals related to underlying human physiological phenomena. A few examples of data captured as part of this project are heart rate, breathing rate, facial temperature, cerebral hemodynamic response and muscle activity.

Current technology advances allow for signals related to human physiology to be captured with less invasive sensors and often in more ecologically valid environments. This in turn offers opportunities for collecting these data while operators are performing various types of jobs in order to better understand how changes in operator states reflect in the data. The hope is that this will lead to guidelines on how to better design jobs.

DigiTOP Study: Physiological indicators of task demand, fatigue, and cognition in future digital manufacturing environments

As Digital Manufacturing transforms traditionally physical work into more cognitive work (for example, tasks involving system monitoring), new methods are required for estimating worker’s levels of mental workload, situation awareness, and other cognitive states relevant to optimising performance in the joint-cognitive manufacturing system. Some physiological measures have shown promise for detecting changes in cognitive state, and recent advances in sensor technology offer minimally-invasive ways to monitor our cognitive activity. Previous research in functional near-infrared spectroscopy, for example, has observed changes in cerebral hemodynamic response during periods of high demand within tasks.

In DigiTOP, our work has explored the use of physiological sensing for operator state monitoring in a range of manufacturing scenarios. In one study, we investigated the relationships among task demand, fatigue, and attention degradation in a sustained attention task, and their collective association with changes in heart rate, breathing rate, nose temperature and hemodynamic response in the prefrontal cortex and middle temporal gyrus.

man sitting in-front of two computer monitors with head sensor son

Image: Physiological data (fNIRS and facial thermography) being collected during a sustained attention task.

Findings

Analysis revealed a small but significant effect of fatigue on heart rate relative to baseline, breathing rate and hemodynamic response. Task demand had a small but significant effect on breathing rate and nose temperature, both relative to a baseline measurement, but no difference between levels of demand was observed in heart rate or hemodynamic response. Our results provide insight into what physiological data can tell us about cognitive state, ability to focus, and the impact of fatigue over time, while also pointing towards limitations of existing technology and challenges for future research.

Please click on the link to go directly to the publication 

Recommended Reading

Charles, R. L., & Nixon, J. (2019). Measuring mental workload using physiological measures: a systematic review. Applied ergonomics, 74, 221-232