PhysioLab
Both for the investigation of human-machine interactions and for the analysis of workplaces and work activities, the ifab has access to various instruments for recording objective physiological data. These allow conclusions to be drawn about the physical and mental strain on the participants in the study.
System for recording physiological data
Varioport
The "Varioport" biosignal recorder enables parallel recording of electrocardiography (ECG), electromyography (EMG) and electrodermal activity (EDA) with 16 channels and a sampling rate of 400 Hz. Due to its small dimensions and the direct storage of data on memory cards, the device is suitable for a wide range of applications and does not restrict the subject.
EDA
The recording of skin conductivity (electrodermal activity) is based on the increased activity of the sympathetic nervous system as a reaction of the human body to emotional stimuli. The triggered increase in sweat secretion reduces the skin's conduction resistance in the short term. By applying two electrodes a short distance apart, this drop in resistance can be recorded and then analyzed in conjunction with information about the stimuli acting on the skin.
EMG
By analyzing voluntary muscle activation - known as electromyography - physical strain can be investigated, particularly during physical work activities.
ECG
Like electromyography, the recording of the heart rate using surface sensors (electrocardiography) is based on the recording of potential changes, in this case specifically in the heart muscles. Several influencing factors must be taken into account for the change in heart rate, such as physical activity, mental and emotional stress.
Our research is currently also examining the reliability and validity of two fitness trackers. The aim of this evaluation is to determine whether small, wireless PPG devices can replace an ECG in field research. The systems are based on photoplethysmography (PPG).
PPG
PPG is a light-based method for determining the heart rate that has also been used in commercial products (fitness trackers, smartwatches) for several years. PPG is based on the following principle:
- The measuring device is positioned over the area to be examined and illuminates the skin surface with a high flashing frequency.
- A photodiode registers changes in the amount of light absorbed.
- The heart rate can be calculated from the course of the change.
Motion measurement systems
MyoMotion from Noraxon
The MyoMotion system can be used to record human movements in the laboratory with a high degree of accuracy. The basis for this is the combination of up to 16 inertial sensors, which can be freely positioned on the body. The wireless transmission of the data gives the test subject unrestricted freedom of movement. Data is collected in parallel by the gyroscope, accelerometer and magnetometer at a maximum sampling rate of 200 Hz and combined to create a detailed overall picture.
CAPTIV T-Sens Motion from Tea Ergo
The CAPTIV system is a system with which human movements can be recorded in the laboratory and directly at workstations. This makes it possible to examine the ergonomic situation directly at production workstations and in real time. With a sampling rate of up to 128 Hz and the flexible fixation of the 13 sensors on the body, almost the entire body posture can be analyzed simultaneously. The associated software also enables the detailed evaluation of movement data synchronized with other physiological data, such as heart rate.