Physiological Signal

One of the most challenging activities of the group is the analysis and recognition of electrophysiological signals for device control. Electrical signals, such as the electromyography (EMG) and electroencephalography (EEG), are recorded, processed and translated into a command to pilot an external device, such as a virtual limb, a robotic hand, a spelling device, a domotic interface, in the so called human-machine interface (HMI) technology.

EMG

It consists in the recording of the electrical activity of the skeletal muscles by means of sensors, named electrodes. It can be recorded both on muscles surfaces, and in this case it is a non-invasive data acquisition called surface EMG (sEMG) or inside muscles, and in this case it is an invasive data acquisition called intramuscular EMG (iEMG). By recording muscles electrical activity, it is possible to reconstruct precise body movements; for example, by recording forearms muscles activity, it is possible to reconstruct hand movements. This finds noteworthy applications in the field of rehabilitation and functionalities augmentation of upper-limb amputees. Our group is involved in a project with the INAIL centre, for the recognition of hand movements in trans-radial amputees and the following treatment of phantom limb pain.

EEG

It consists in the recording of the electrical activity of brain cells, named neurons, by means of electrodes which are positioned on the scalp in predefined positions following international standards (e.g. 10-20 systems). By recording brain activity, it is possible to decode subjects’ intention and this can be a valuable mean to translate human brain signal variations in commands towards an output peripheral, in the so-called Brain-Computer Interface (BCI) application. A BCI system allows decoding human activities into output commands and is mainly intended for severely disabled people (e.g. locked-in persons) who, after severe traumas or degenerative pathologies, have lost any control on all the body muscles and therefore any possibility of communication.