Tutorial. Surface EMG detection, conditioning and pre-processing: Best practices

This tutorial is aimed primarily to non-engineers, using or planning to use surface electromyography (sEMG) as an assessment tool for muscle evaluation in the prevention, monitoring, assessment and rehabilitation fields. The main purpose is to explain basic concepts related to: (a) signal detection (electrodes, electrode–skin interface, noise, ECG and power line interference), (b) basic signal properties, such as amplitude and bandwidth, (c) parameters of the front-end amplifier (input impedance, noise, CMRR, bandwidth, etc.), (d) techniques for interference and artifact reduction, (e) signal filtering, (f) sampling and (g) A/D conversion, These concepts are addressed and discussed, with examples. The second purpose is to outline best practices and provide general guidelines for proper signal detection, conditioning and A/D conversion, aimed to clinical operators and biomedical engineers. Issues related to the sEMG origin and to electrode size, interelectrode distance and location, have been discussed in a previous tutorial. Issues related to signal processing for information extraction will be discussed in a subsequent tutorial

Low cost inkjet printing for the fast prototyping of surface EMG detection systems

In the last years, printing techniques have been developed for the realization of electronic circuits using functional inks. In this field inkjet printing technology has a number of attractive features and received a lot of interest with the development of specifically designed functional inks, including conductive inks based on silver nanoparticles or organic polymers. Some works in literature investigated the use of inkjet printing technique for the development of electrophysiological sensors. The aim of this work was to explore the potentialities of low cost inkjet printing for the prototyping of high-density electrode arrays for the detection of surface electromyographic signal (sEMG). A low cost inkjet system for the printing of conductive tracks based on standard office printer has been setup and tested for the prototyping of sEMG detection systems. The setup allowed the printing of high density bi-dimensional electrode arrays. The sEMG detection systems have been tested on the abductor pollicis muscle and biceps brachii muscle during isometric and dynamic contractions. The detected signals show a good quality and a stable contact without movement artifacts. The proposed system offers the possibility to design and print electrode arrays with different electrode patterns in a few minutes. This characteristic allows developing sEMG detection systems that can be adapted to the anatomy of the muscles under investigation in a short time