Biosignal

Biosignal is a summarizing term for all kinds of signals that can be (continually) measured and monitored from biological beings. The term biosignal is often used to mean bio-electrical signal but in fact, biosignal refers to both electrical and non-electrical signals.

Electrical biosignals ("bio-electrical" signals) are usually taken to be (changes in) electric currents produced by the sum of electrical potential differences across a specialized tissue, organ or cell system like the nervous system. Thus, among the best-known bio-electrical signals are the

• Electroencephalogram (EEG)
• Magnetoencephalogram (MEG)
• Galvanic skin response (GSR)
• Electrocardiogram (ECG)
• Electromyogram (EMG)
• Heart Rate Variability (HRV)

Electrical currents and changes in electrical resistances across tissues can also be measured from plants.

Bio-signals may also refer to any non-electrical signal that is capable of being monitored from biological beings, such as mechanical signals (e.g. the mechanomyogram or MMG), acoustic signals (e.g. phonetic and non-phonetic utterances, breathing), chemical signals (e.g. pH, oxygenation) and optical signals (e.g. movements).

Applications

• Using electroencephalograph signals for task classification and activity recognition Microsoft
• NASA scientists use hands-off approach to land passengers jet

Hardware

University project

• University of Vienna : cours Biomedical Engineering, Electromyography (EMG)
• Electroencephalographe,EEG, sans fil ( Cornell University, Ithaca, NY, USA)

See also

• Bioindicator
• Biomarker
• Biosignature
• Molecular marker
• Multimedia Information Retrieval