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.
High-performance mobile fNIR Imaging Systems are stand-alone functional brain imaging solutions for continuous NIR spectroscopy (NIRS). These top of the line systems provide cognitive function assessment and eliminate a great many of the drawbacks of a functional MRI. Mobile subjects are comfortable and can respond naturally in real-world situations to take a test or perform mobile […]
February 14, 2019 BIOPAC Systems, Inc. Goleta, CA USA New “Smart Amplifiers” make it easier than ever for life science researchers to get great data Fast Setup & High Performance Smart Amplifiers improve performance by amplifying the physiological signal close to the subject, which allows a high-level voltage connection to the data acquisition system and reduces noise artifact. […]
BIOPAC provides software and hardware that allows research teams to record and analyze numerous body signals for physiological experimentation. Here are a few notable studies using BIOPAC equipment that cover Respiration, EEG, and Neuromarketing. Breathe Easy In this study, a mathematician from Simpson College uses her skills and students’ respiratory studies conducted with Biopac Student Lab equipment (BSL […]