The device was designed for researchers dealing with human psychophysiological reactions. The system may be used during strictly scientific experiments as well as during marketing and opinion research. Thanks to advanced measurement techniques and signal processing methods, combined with mobility and comfort of measurement of both reactions on the wrist, GSR is excellent in situations in which other systems fail.
Measurement of galvanic skin response, that is changes in electrical resistance of the skin caused by activity of sweat glands controlled by sympathetic nervous system, is carried out using the Féré method. The body is subjected to low voltage between two electrodes attached to the skin. The current flowing through the tissue under the influence of this voltage is measured. Alternating current stimulation with two stimulation frequencies was applied in the project. The data are filtered appropriately and processed, which enables GSR measurement free of distortions.
The pulse is measured using reflectance photoplethysmography (PPG). It is a non-invasive and pain-free method of measurement of blood flow and changes in blood volume in the skin. An intelligent algorithm of heartbeat detection allows for determination of the time between subsequent heartbeats and calculation of BPM approximated between subsequent samples.