Biopotential acquisition systems

FEDERICO GUERRERO; ENRIQUE SPINELLI

Medicine-Based Informatics and Engineering

Springer

Año: 2022;

Electrical potentials from a biological origin, or biopotentials, have been known and explored for a long time by medicine together with engineering. They allow obtaining hints about our health in multiple clinical applications and even providing a pathway through which our will can manifest in the environment in brain-computer interfaces. The systems that allow acquiring these biopotentials have evolved for more than a century and can be considered a very mature technology in some respects. However, the requirements and conditions under which they must operate have also evolved. Crisis such as that presented by COVID-19 expose the need for robust, low-cost, pervasive mobile health devices. Challenging applications presented in this book, such as electromyographic (EMG) signals recording on free-roaming walkers, and electroencephalogram (EEG) signal acquisition for rehabilitation therapies, show that biopotential acquisition systems must operate in non-conditioned environments: they have moved from laboratories and medical offices to homes, gyms, rehabilitation centers, sports fields and even swimming pools. Moreover, the 24-hour availability of networked digital data pushes for pervasive, ever-present monitoring as is incipiently available for electrocardiograph (ECG) signals. This new framework claims for low-cost, portable, and compact systems, thus leading their evolution towards wearable devices, which could be installed on the patient as easily as a piece of clothing. In this chapter, the design of biopotential amplifiers is contextualized in this connected environment. The harsh operational conditions faced by wearable devices are presented. Focus is made on the challenges of electromagnetic interference (EMI) sources and high-amplitude motion artifacts, including a general approach to power-line interference analysis.