For most biopotential recordings, it is important to provide a low impedance contact with the tissue underneath the skin at the electrode site. Consequently skin should be abraded with pumice, an ELPAD or ELPREP. Alcohol prep pads are generally not preferred because they dry the skin. The purpose of abrasion is to remove dead cells from the outer layer of skin. These cells form an electrical barrier. Electrical communication from the electrode surface to the underlying tissue is most often through a water-based gel. For good recordings, this gel must soak into the skin. As alcohol dries out the skin, it slows the process of establishing the liquid bridge between electrode and tissue.
One exception where abrasion is not recommended is measurement of electrodermal activity (skin conductance). Here skin should be rinsed but neither washed with soap nor abraded. As the conductivity of the skin at the electrode site is the variable to be measured in this case, no steps should be taken to modify that conductance artificially.
Eyes are the window to the soul and, more importantly, the brain. Psychophysiology, neuroscience, and consumer neuroscience researchers use eye tracking technology to understand emotion, behavior, subject response, decision-making, and human performance—and to help improve products and services. But not everyone knows where to start or how and why to use this important technology. A panel of eye tracking experts will present typical use cases and the latest eye tracking technology.
Join this online presentation with Q&A to learn the fundamentals of eye tracking!
Recent physiological studies feature BIOPAC’s Wireless BioNomadix Data Recorders Using Metronomes and Rhythmic stimulation to help people with Parkinson’s disease walk For those living with Parkinson’s disease, even simple tasks can take too long to accomplish properly, such as crossing a room or picking up an object. In this study, participants with diagnosed cases of […]
BIOPAC’s just released Introductory ECG Guide addresses fundamental to advanced concerns to optimize electrocardiography data recording and analysis. Topics include: ECG Complex; Electrical and Mechanical Sequence of a Heartbeat; Systole and Diastole; Configurations for Lead I, Lead II, Lead III, 6-lead ECG, 12-lead ECG, precordial leads; Ventricular Late Potentials (VLPs); ECG Measurement Tools; Automated Analysis Routines […]