BIOSIGNALS

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) electrical 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 :

1.)Electroencephalogram (EEG)



2.)Magnetoencephalogram (MEG)



3.)Galvanic skin response (GSR)



4.)Electrocardiogram (ECG)



5.)Electromyogram (EMG)



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) and visual signals (e.g. movements).