Psychophysiological Measurements

Psychophysiological parameters provide detailed insights into the physical and/or psychological strain on users when interacting with technical systems, user interfaces and workplaces. They supplement subjective methods such as questionnaires or interviews with more objective measures that cannot be directly influenced by users. In research and industrial projects at the IAD, muscle activity, cardiac activity (heart rate, heart rate variability) and electrodermal activity (skin conductance) in particular are recorded using state-of-the-art measurement systems and then analyzed descriptively and statistically.

Electromyography (EMG) enables the measurement of muscular activity and is used in particular to analyze physical strain, muscular fatigue and to determine the “physiological costs” as a measure of the ergonomic quality and compatibility of workplaces and work equipment.

Electrocardiography (ECG) can be used to precisely measure heart rate and related parameters. Both heart rate and heart rate variability are sensitive indicators of physical and mental strain: For example, the heart rate increases during mental strain, while reduced heart rate variability can indicate increased mental strain.

To record psychological reactions, the electrodermal activity (EDA) respectively skin conductance is used, which increases during mental and emotional strain, as sweat production increases the skin conductance due to moisture.

Example applications:

Noraxon Ultium EMG
Noraxon Ultium EMG
  • The IAD uses the Noraxon Ultium EMG measurement system, which represents the gold standard for EMG technology with a measurement frequency of up to 4000 Hz. The myoelectric signals are recorded wirelessly via surface electrodes, which are applied locally to the relevant muscles according to scientific standards, such as those of the SENIAM project. EMG was used as part of the development and evaluation of optimal storage bin allocation in manual order picking by recording the muscle strain in the arm-shoulder and trunk area of manual order pickers in a user study with a set-up warehouse layout. The IAD also used EMG to analyze the effect of passive and active exoskeletons on the muscle strain in the lower back and arm-shoulder area of workers in representative activities in automotive assembly and construction with unfavorable postures such as overhead work or moving heavy loads.
Polar H10 Chest Strap
Polar H10 Chest Strap
  • Polar H10 chest strap worn under the chest is used to record heart activity. The system records the heart rate or the R-pulses that are emitted via the skin. In an empirical study at the IAD's human-robot collaboration workstation, where users interacted with the Sawyer robot, the influence of users' given freedom for designing and acting in their interaction with the robot on their strain was investigated – both subjectively by completing the NASA Task Load Index and objectively by recording their heart rate and heart rate variability with the Polar H10 chest strap.
Shimmer3 GSR+ Unit
Shimmer3 GSR+ Unit
  • The Shimmer3 GSR+ unit is used for real-time detection of EDA and measures the conductivity of the skin between two electrodes on the fingers. Increased activity of the sweat glands as a result of a stimulus increases moisture, which improves the skin conductance as the balance of positive and negative ions changes. In addition, the Shimmer3 GSR+ unit can optically detect the pulse with an ear clip or a pulse probe on the index fingertip to estimate the heart rate. Thanks to its compatibility with virtual reality headsets, it was used in a virtual reality study to measure the mental arousal of pedestrians interacting with automated vehicles.
Empatica EmbracePlus
Empatica EmbracePlus
  • In addition to specialized measurement systems, the IAD also uses wearables such as smartwatches (e.g. the Empatica EmbracePlus), which are ideal for long-term digital workplace analyses. They record physiological parameters such as electrodermal activity, heart activity, skin temperature and movement data, do not restrict the wearer's mobility and are unobtrusive when worn.

If you would like to know whether the method is suitable for your application, you are welcome to contact us using the contact button on the right. Your enquiry will then be forwarded directly to our experts.