Mental Workload Measurements through Low-Cost and Wearable Sensors: Insights into Accuracy, Obtrusiveness, and Research Usability of Three Instruments

Opportunities to measure mental workload through more objective and unobtrusive manners have emerged with the affordability of low-cost and wearable psychophysiological sensors. The current study has predominantly a methodological focus to investigate the selected devices in terms of accuracy, obtrusiveness and usability for research purposes. Measurements to compare these sensors are conducted in a simulator setting with train traffic controllers. Two sensors are assessed on their accuracy as a tool to measure heart rate variability (HRV) as an objective indicator of mental workload: the E3 sensor from Empatica (placed on the wrist) and HeartMath’s EmWave Pro system (placed at the earlobe). The Food and Drug Administration (FDA) approved BioPatch from Zephyr Technology (placed on the chest) was used as a gold standard to compare the data of the other two devices regarding their accuracy, in which linear dependencies for 6 out of 10 HRV parameters were found between the EmWave and BioPatch data and for 1 out of 10 for the E3 sensor. In terms of research usability of the sensors, both the E3 and BioPatch had issues with acquiring either sufficiently high data recording confidence values or normal distributions. However the BioPatch output files required no post-processing, which reduced costs and efforts in the analysis stage. All three sensors were not perceived as obtrusive by the participants. A recommendation for the use of sensors is provided with nuances based on researchers’ requirements and prioritizations regarding the design of a study.


  • English

Media Info

  • Media Type: Web
  • Features: Figures; Photos; References; Tables;
  • Pagination: 15p
  • Monograph Title: TRB 95th Annual Meeting Compendium of Papers

Subject/Index Terms

Filing Info

  • Accession Number: 01589937
  • Record Type: Publication
  • Report/Paper Numbers: 16-2751
  • Files: TRIS, TRB, ATRI
  • Created Date: Jan 12 2016 5:13PM